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linux-7.2.3/arch/x86/boot/.gitignore

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+# SPDX-License-Identifier: GPL-2.0-only
+bootsect
+bzImage
+cpustr.h
+mkcpustr
+voffset.h
+zoffset.h
+setup
+setup.bin
+setup.elf
+fdimage
+mtools.conf
+image.iso
+hdimage
+tools/

linux-7.2.3/arch/x86/boot/Makefile

@@ -0,0 +1,139 @@
+#
+# arch/x86/boot/Makefile
+#
+# This file is subject to the terms and conditions of the GNU General Public
+# License.  See the file "COPYING" in the main directory of this archive
+# for more details.
+#
+# Copyright (C) 1994 by Linus Torvalds
+# Changed by many, many contributors over the years.
+#
+
+# If you want to preset the SVGA mode, uncomment the next line and
+# set SVGA_MODE to whatever number you want.
+# Set it to -DSVGA_MODE=NORMAL_VGA if you just want the EGA/VGA mode.
+# The number is the same as you would ordinarily press at bootup.
+
+SVGA_MODE	:= -DSVGA_MODE=NORMAL_VGA
+
+targets		:= vmlinux.bin setup.bin setup.elf bzImage
+targets		+= fdimage fdimage144 fdimage288 image.iso hdimage
+subdir-		:= compressed
+
+setup-y		+= a20.o bioscall.o cmdline.o copy.o cpu.o cpuflags.o cpucheck.o
+setup-y		+= early_serial_console.o edd.o header.o main.o memory.o
+setup-y		+= pm.o pmjump.o printf.o regs.o string.o tty.o video.o
+setup-y		+= video-mode.o version.o
+setup-$(CONFIG_X86_APM_BOOT) += apm.o
+
+# The link order of the video-*.o modules can matter.  In particular,
+# video-vga.o *must* be listed first, followed by video-vesa.o.
+# Hardware-specific drivers should follow in the order they should be
+# probed, and video-bios.o should typically be last.
+setup-y		+= video-vga.o
+setup-y		+= video-vesa.o
+setup-y		+= video-bios.o
+
+targets		+= $(setup-y)
+hostprogs	+= mkcpustr
+
+HOST_EXTRACFLAGS += -I$(srctree)/tools/include \
+		    -include include/generated/autoconf.h \
+	            -D__EXPORTED_HEADERS__
+
+$(obj)/cpu.o: $(obj)/cpustr.h
+
+quiet_cmd_cpustr = CPUSTR  $@
+      cmd_cpustr = $(obj)/mkcpustr > $@
+$(obj)/cpustr.h: $(obj)/mkcpustr FORCE
+	$(call if_changed,cpustr)
+targets += cpustr.h
+
+# ---------------------------------------------------------------------------
+
+KBUILD_CFLAGS	:= $(REALMODE_CFLAGS) -D_SETUP
+KBUILD_AFLAGS	:= $(KBUILD_CFLAGS) -D__ASSEMBLY__
+KBUILD_CFLAGS	+= -fno-asynchronous-unwind-tables
+KBUILD_CFLAGS	+= $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
+
+$(obj)/bzImage: asflags-y  := $(SVGA_MODE)
+
+quiet_cmd_image = BUILD   $@
+      cmd_image = (dd if=$< bs=4k conv=sync status=none; cat $(filter-out $<,$(real-prereqs))) >$@
+
+$(obj)/bzImage: $(obj)/setup.bin $(obj)/vmlinux.bin FORCE
+	$(call if_changed,image)
+	@$(kecho) 'Kernel: $@ is ready' ' (#'$(or $(KBUILD_BUILD_VERSION),`cat .version`)')'
+
+OBJCOPYFLAGS_vmlinux.bin := -O binary -R .note -R .comment -S
+$(obj)/vmlinux.bin: $(obj)/compressed/vmlinux FORCE
+	$(call if_changed,objcopy)
+
+SETUP_OBJS = $(addprefix $(obj)/,$(setup-y))
+
+sed-zoffset := -e 's/^\([0-9a-fA-F]*\) [a-zA-Z] \(startup_32\|efi.._stub_entry\|efi\(32\)\?_pe_entry\|input_data\|kernel_info\|_end\|_ehead\|_text\|_e\?data\|_e\?sbat\|z_.*\)$$/\#define ZO_\2 0x\1/p'
+
+quiet_cmd_zoffset = ZOFFSET $@
+      cmd_zoffset = $(NM) $< | sed -n $(sed-zoffset) > $@
+
+targets += zoffset.h
+$(obj)/zoffset.h: $(obj)/compressed/vmlinux FORCE
+	$(call if_changed,zoffset)
+
+
+AFLAGS_header.o += -I$(objtree)/$(obj)
+$(obj)/header.o: $(obj)/zoffset.h
+
+LDFLAGS_setup.elf	:= -m elf_i386 -z noexecstack -T
+$(obj)/setup.elf: $(src)/setup.ld $(SETUP_OBJS) FORCE
+	$(call if_changed,ld)
+
+OBJCOPYFLAGS_setup.bin	:= -O binary
+$(obj)/setup.bin: $(obj)/setup.elf FORCE
+	$(call if_changed,objcopy)
+
+$(obj)/compressed/vmlinux: FORCE
+	$(Q)$(MAKE) $(build)=$(obj)/compressed $@
+
+# Set this if you want to pass append arguments to the
+# bzdisk/fdimage/hdimage/isoimage kernel
+FDARGS =
+# Set this if you want one or more initrds included in the image
+FDINITRD =
+
+imgdeps = $(obj)/bzImage $(obj)/mtools.conf $(src)/genimage.sh
+
+$(obj)/mtools.conf: $(src)/mtools.conf.in
+	sed -e 's|@OBJ@|$(obj)|g' < $< > $@
+
+targets += mtools.conf
+
+# genimage.sh requires bash, but it also has a bunch of other
+# external dependencies.
+quiet_cmd_genimage = GENIMAGE $3
+      cmd_genimage = $(BASH) $(src)/genimage.sh $2 $3 $(obj)/bzImage \
+		$(obj)/mtools.conf '$(FDARGS)' $(FDINITRD)
+
+PHONY += bzdisk fdimage fdimage144 fdimage288 hdimage isoimage
+
+# This requires write access to /dev/fd0
+# All images require syslinux to be installed; hdimage also requires
+# EDK2/OVMF if the kernel is compiled with the EFI stub.
+bzdisk: $(imgdeps)
+	$(call cmd,genimage,bzdisk,/dev/fd0)
+
+fdimage fdimage144: $(imgdeps)
+	$(call cmd,genimage,fdimage144,$(obj)/fdimage)
+	@$(kecho) 'Kernel: $(obj)/fdimage is ready'
+
+fdimage288: $(imgdeps)
+	$(call cmd,genimage,fdimage288,$(obj)/fdimage)
+	@$(kecho) 'Kernel: $(obj)/fdimage is ready'
+
+hdimage: $(imgdeps)
+	$(call cmd,genimage,hdimage,$(obj)/hdimage)
+	@$(kecho) 'Kernel: $(obj)/hdimage is ready'
+
+isoimage: $(imgdeps)
+	$(call cmd,genimage,isoimage,$(obj)/image.iso)
+	@$(kecho) 'Kernel: $(obj)/image.iso is ready'

linux-7.2.3/arch/x86/boot/a20.c

@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007-2008 rPath, Inc. - All Rights Reserved
+ *   Copyright 2009 Intel Corporation; author H. Peter Anvin
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Enable A20 gate (return -1 on failure)
+ */
+
+#include "boot.h"
+
+#define MAX_8042_LOOPS	100000
+#define MAX_8042_FF	32
+
+static int empty_8042(void)
+{
+	u8 status;
+	int loops = MAX_8042_LOOPS;
+	int ffs   = MAX_8042_FF;
+
+	while (loops--) {
+		io_delay();
+
+		status = inb(0x64);
+		if (status == 0xff) {
+			/* FF is a plausible, but very unlikely status */
+			if (!--ffs)
+				return -1; /* Assume no KBC present */
+		}
+		if (status & 1) {
+			/* Read and discard input data */
+			io_delay();
+			(void)inb(0x60);
+		} else if (!(status & 2)) {
+			/* Buffers empty, finished! */
+			return 0;
+		}
+	}
+
+	return -1;
+}
+
+/* Returns nonzero if the A20 line is enabled.  The memory address
+   used as a test is the int $0x80 vector, which should be safe. */
+
+#define A20_TEST_ADDR	(4*0x80)
+#define A20_TEST_SHORT  32
+#define A20_TEST_LONG	2097152	/* 2^21 */
+
+static int a20_test(int loops)
+{
+	int ok = 0;
+	int saved, ctr;
+
+	set_fs(0x0000);
+	set_gs(0xffff);
+
+	saved = ctr = rdfs32(A20_TEST_ADDR);
+
+	while (loops--) {
+		wrfs32(++ctr, A20_TEST_ADDR);
+		io_delay();	/* Serialize and make delay constant */
+		ok = rdgs32(A20_TEST_ADDR+0x10) ^ ctr;
+		if (ok)
+			break;
+	}
+
+	wrfs32(saved, A20_TEST_ADDR);
+	return ok;
+}
+
+/* Quick test to see if A20 is already enabled */
+static int a20_test_short(void)
+{
+	return a20_test(A20_TEST_SHORT);
+}
+
+/* Longer test that actually waits for A20 to come on line; this
+   is useful when dealing with the KBC or other slow external circuitry. */
+static int a20_test_long(void)
+{
+	return a20_test(A20_TEST_LONG);
+}
+
+static void enable_a20_bios(void)
+{
+	struct biosregs ireg;
+
+	initregs(&ireg);
+	ireg.ax = 0x2401;
+	intcall(0x15, &ireg, NULL);
+}
+
+static void enable_a20_kbc(void)
+{
+	empty_8042();
+
+	outb(0xd1, 0x64);	/* Command write */
+	empty_8042();
+
+	outb(0xdf, 0x60);	/* A20 on */
+	empty_8042();
+
+	outb(0xff, 0x64);	/* Null command, but UHCI wants it */
+	empty_8042();
+}
+
+static void enable_a20_fast(void)
+{
+	u8 port_a;
+
+	port_a = inb(0x92);	/* Configuration port A */
+	port_a |=  0x02;	/* Enable A20 */
+	port_a &= ~0x01;	/* Do not reset machine */
+	outb(port_a, 0x92);
+}
+
+/*
+ * Actual routine to enable A20; return 0 on ok, -1 on failure
+ */
+
+#define A20_ENABLE_LOOPS 255	/* Number of times to try */
+
+int enable_a20(void)
+{
+       int loops = A20_ENABLE_LOOPS;
+       int kbc_err;
+
+       while (loops--) {
+	       /* First, check to see if A20 is already enabled
+		  (legacy free, etc.) */
+	       if (a20_test_short())
+		       return 0;
+
+	       /* Next, try the BIOS (INT 0x15, AX=0x2401) */
+	       enable_a20_bios();
+	       if (a20_test_short())
+		       return 0;
+
+	       /* Try enabling A20 through the keyboard controller */
+	       kbc_err = empty_8042();
+
+	       if (a20_test_short())
+		       return 0; /* BIOS worked, but with delayed reaction */
+
+	       if (!kbc_err) {
+		       enable_a20_kbc();
+		       if (a20_test_long())
+			       return 0;
+	       }
+
+	       /* Finally, try enabling the "fast A20 gate" */
+	       enable_a20_fast();
+	       if (a20_test_long())
+		       return 0;
+       }
+
+       return -1;
+}

linux-7.2.3/arch/x86/boot/apm.c

@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *   Copyright 2009 Intel Corporation; author H. Peter Anvin
+ *
+ *   Original APM BIOS checking by Stephen Rothwell, May 1994
+ *   (sfr@canb.auug.org.au)
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Get APM BIOS information
+ */
+
+#include "boot.h"
+
+int query_apm_bios(void)
+{
+	struct biosregs ireg, oreg;
+
+	/* APM BIOS installation check */
+	initregs(&ireg);
+	ireg.ah = 0x53;
+	intcall(0x15, &ireg, &oreg);
+
+	if (oreg.flags & X86_EFLAGS_CF)
+		return -1;		/* No APM BIOS */
+
+	if (oreg.bx != 0x504d)		/* "PM" signature */
+		return -1;
+
+	if (!(oreg.cx & 0x02))		/* 32 bits supported? */
+		return -1;
+
+	/* Disconnect first, just in case */
+	ireg.al = 0x04;
+	intcall(0x15, &ireg, NULL);
+
+	/* 32-bit connect */
+	ireg.al = 0x03;
+	intcall(0x15, &ireg, &oreg);
+
+	boot_params.apm_bios_info.cseg        = oreg.ax;
+	boot_params.apm_bios_info.offset      = oreg.ebx;
+	boot_params.apm_bios_info.cseg_16     = oreg.cx;
+	boot_params.apm_bios_info.dseg        = oreg.dx;
+	boot_params.apm_bios_info.cseg_len    = oreg.si;
+	boot_params.apm_bios_info.cseg_16_len = oreg.hsi;
+	boot_params.apm_bios_info.dseg_len    = oreg.di;
+
+	if (oreg.flags & X86_EFLAGS_CF)
+		return -1;
+
+	/* Redo the installation check as the 32-bit connect;
+	   some BIOSes return different flags this way... */
+
+	ireg.al = 0x00;
+	intcall(0x15, &ireg, &oreg);
+
+	if ((oreg.eflags & X86_EFLAGS_CF) || oreg.bx != 0x504d) {
+		/* Failure with 32-bit connect, try to disconnect and ignore */
+		ireg.al = 0x04;
+		intcall(0x15, &ireg, NULL);
+		return -1;
+	}
+
+	boot_params.apm_bios_info.version = oreg.ax;
+	boot_params.apm_bios_info.flags   = oreg.cx;
+	return 0;
+}
+

linux-7.2.3/arch/x86/boot/bioscall.S

@@ -0,0 +1,79 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* -----------------------------------------------------------------------
+ *
+ *   Copyright 2009-2014 Intel Corporation; author H. Peter Anvin
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * "Glove box" for BIOS calls.  Avoids the constant problems with BIOSes
+ * touching registers they shouldn't be.
+ */
+
+	.code16
+	.section ".inittext","ax"
+	.globl	intcall
+	.type	intcall, @function
+intcall:
+	/* Self-modify the INT instruction.  Ugly, but works. */
+	cmpb	%al, 3f
+	je	1f
+	movb	%al, 3f
+	jmp	1f		/* Synchronize pipeline */
+1:
+	/* Save state */
+	pushfl
+	pushw	%fs
+	pushw	%gs
+	pushal
+
+	/* Copy input state to stack frame */
+	subw	$44, %sp
+	movw	%dx, %si
+	movw	%sp, %di
+	movw	$11, %cx
+	rep movsl
+
+	/* Pop full state from the stack */
+	popal
+	popw	%gs
+	popw	%fs
+	popw	%es
+	popw	%ds
+	popfl
+
+	/* Actual INT */
+	.byte	0xcd		/* INT opcode */
+3:	.byte	0
+
+	/* Push full state to the stack */
+	pushfl
+	pushw	%ds
+	pushw	%es
+	pushw	%fs
+	pushw	%gs
+	pushal
+
+	/* Re-establish C environment invariants */
+	cld
+	movzwl	%sp, %esp
+	movw	%cs, %ax
+	movw	%ax, %ds
+	movw	%ax, %es
+
+	/* Copy output state from stack frame */
+	movw	68(%esp), %di	/* Original %cx == 3rd argument */
+	andw	%di, %di
+	jz	4f
+	movw	%sp, %si
+	movw	$11, %cx
+	rep movsl
+4:	addw	$44, %sp
+
+	/* Restore state and return */
+	popal
+	popw	%gs
+	popw	%fs
+	popfl
+	retl
+	.size	intcall, .-intcall

linux-7.2.3/arch/x86/boot/bitops.h

@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Very simple bitops for the boot code.
+ */
+
+#ifndef BOOT_BITOPS_H
+#define BOOT_BITOPS_H
+#define _LINUX_BITOPS_H		/* Inhibit inclusion of <linux/bitops.h> */
+
+#include <linux/types.h>
+#include <asm/asm.h>
+
+static inline bool constant_test_bit(int nr, const void *addr)
+{
+	const u32 *p = addr;
+	return ((1UL << (nr & 31)) & (p[nr >> 5])) != 0;
+}
+static inline bool variable_test_bit(int nr, const void *addr)
+{
+	bool v;
+	const u32 *p = addr;
+
+	asm("btl %2,%1" : "=@ccc" (v) : "m" (*p), "Ir" (nr));
+	return v;
+}
+
+#define test_bit(nr,addr) \
+(__builtin_constant_p(nr) ? \
+ constant_test_bit((nr),(addr)) : \
+ variable_test_bit((nr),(addr)))
+
+static inline void set_bit(int nr, void *addr)
+{
+	asm("btsl %1,%0" : "+m" (*(u32 *)addr) : "Ir" (nr));
+}
+
+#endif /* BOOT_BITOPS_H */

linux-7.2.3/arch/x86/boot/boot.h

@@ -0,0 +1,330 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *   Copyright 2009 Intel Corporation; author H. Peter Anvin
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Header file for the real-mode kernel code
+ */
+
+#ifndef BOOT_BOOT_H
+#define BOOT_BOOT_H
+
+#define STACK_SIZE	1024	/* Minimum number of bytes for stack */
+
+#ifndef __ASSEMBLER__
+
+#include <linux/stdarg.h>
+#include <linux/types.h>
+#include <linux/edd.h>
+#include <asm/setup.h>
+#include <asm/asm.h>
+#include "bitops.h"
+#include "ctype.h"
+#include "cpuflags.h"
+#include "io.h"
+
+/* Useful macros */
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
+
+extern struct setup_header hdr;
+extern struct boot_params boot_params;
+
+#define cpu_relax()	asm volatile("pause")
+
+static inline void io_delay(void)
+{
+	const u16 DELAY_PORT = 0x80;
+	outb(0, DELAY_PORT);
+}
+
+/* These functions are used to reference data in other segments. */
+
+static inline u16 ds(void)
+{
+	u16 seg;
+	asm("movw %%ds,%0" : "=rm" (seg));
+	return seg;
+}
+
+static inline void set_fs(u16 seg)
+{
+	asm volatile("movw %0,%%fs" : : "rm" (seg));
+}
+static inline u16 fs(void)
+{
+	u16 seg;
+	asm volatile("movw %%fs,%0" : "=rm" (seg));
+	return seg;
+}
+
+static inline void set_gs(u16 seg)
+{
+	asm volatile("movw %0,%%gs" : : "rm" (seg));
+}
+static inline u16 gs(void)
+{
+	u16 seg;
+	asm volatile("movw %%gs,%0" : "=rm" (seg));
+	return seg;
+}
+
+typedef unsigned int addr_t;
+
+static inline u8 rdfs8(addr_t addr)
+{
+	u8 *ptr = (u8 *)absolute_pointer(addr);
+	u8 v;
+	asm volatile("movb %%fs:%1,%0" : "=q" (v) : "m" (*ptr));
+	return v;
+}
+static inline u16 rdfs16(addr_t addr)
+{
+	u16 *ptr = (u16 *)absolute_pointer(addr);
+	u16 v;
+	asm volatile("movw %%fs:%1,%0" : "=r" (v) : "m" (*ptr));
+	return v;
+}
+static inline u32 rdfs32(addr_t addr)
+{
+	u32 *ptr = (u32 *)absolute_pointer(addr);
+	u32 v;
+	asm volatile("movl %%fs:%1,%0" : "=r" (v) : "m" (*ptr));
+	return v;
+}
+
+static inline void wrfs8(u8 v, addr_t addr)
+{
+	u8 *ptr = (u8 *)absolute_pointer(addr);
+	asm volatile("movb %1,%%fs:%0" : "+m" (*ptr) : "qi" (v));
+}
+static inline void wrfs16(u16 v, addr_t addr)
+{
+	u16 *ptr = (u16 *)absolute_pointer(addr);
+	asm volatile("movw %1,%%fs:%0" : "+m" (*ptr) : "ri" (v));
+}
+static inline void wrfs32(u32 v, addr_t addr)
+{
+	u32 *ptr = (u32 *)absolute_pointer(addr);
+	asm volatile("movl %1,%%fs:%0" : "+m" (*ptr) : "ri" (v));
+}
+
+static inline u8 rdgs8(addr_t addr)
+{
+	u8 *ptr = (u8 *)absolute_pointer(addr);
+	u8 v;
+	asm volatile("movb %%gs:%1,%0" : "=q" (v) : "m" (*ptr));
+	return v;
+}
+static inline u16 rdgs16(addr_t addr)
+{
+	u16 *ptr = (u16 *)absolute_pointer(addr);
+	u16 v;
+	asm volatile("movw %%gs:%1,%0" : "=r" (v) : "m" (*ptr));
+	return v;
+}
+static inline u32 rdgs32(addr_t addr)
+{
+	u32 *ptr = (u32 *)absolute_pointer(addr);
+	u32 v;
+	asm volatile("movl %%gs:%1,%0" : "=r" (v) : "m" (*ptr));
+	return v;
+}
+
+static inline void wrgs8(u8 v, addr_t addr)
+{
+	u8 *ptr = (u8 *)absolute_pointer(addr);
+	asm volatile("movb %1,%%gs:%0" : "+m" (*ptr) : "qi" (v));
+}
+static inline void wrgs16(u16 v, addr_t addr)
+{
+	u16 *ptr = (u16 *)absolute_pointer(addr);
+	asm volatile("movw %1,%%gs:%0" : "+m" (*ptr) : "ri" (v));
+}
+static inline void wrgs32(u32 v, addr_t addr)
+{
+	u32 *ptr = (u32 *)absolute_pointer(addr);
+	asm volatile("movl %1,%%gs:%0" : "+m" (*ptr) : "ri" (v));
+}
+
+/* Note: these only return true/false, not a signed return value! */
+static inline bool memcmp_fs(const void *s1, addr_t s2, size_t len)
+{
+	bool diff;
+	asm volatile("fs repe cmpsb"
+		     : "=@ccnz" (diff), "+D" (s1), "+S" (s2), "+c" (len));
+	return diff;
+}
+static inline bool memcmp_gs(const void *s1, addr_t s2, size_t len)
+{
+	bool diff;
+	asm volatile("gs repe cmpsb"
+		     : "=@ccnz" (diff), "+D" (s1), "+S" (s2), "+c" (len));
+	return diff;
+}
+
+/* Heap -- available for dynamic lists. */
+extern char _end[];
+extern char *HEAP;
+extern char *heap_end;
+#define RESET_HEAP() ((void *)( HEAP = _end ))
+static inline char *__get_heap(size_t s, size_t a, size_t n)
+{
+	char *tmp;
+
+	HEAP = (char *)(((size_t)HEAP+(a-1)) & ~(a-1));
+	tmp = HEAP;
+	HEAP += s*n;
+	return tmp;
+}
+#define GET_HEAP(type, n) \
+	((type *)__get_heap(sizeof(type),__alignof__(type),(n)))
+
+static inline bool heap_free(size_t n)
+{
+	return (int)(heap_end-HEAP) >= (int)n;
+}
+
+/* copy.S */
+
+void copy_to_fs(addr_t dst, void *src, size_t len);
+void *copy_from_fs(void *dst, addr_t src, size_t len);
+
+/* a20.c */
+int enable_a20(void);
+
+/* apm.c */
+int query_apm_bios(void);
+
+/* bioscall.c */
+struct biosregs {
+	union {
+		struct {
+			u32 edi;
+			u32 esi;
+			u32 ebp;
+			u32 _esp;
+			u32 ebx;
+			u32 edx;
+			u32 ecx;
+			u32 eax;
+			u32 _fsgs;
+			u32 _dses;
+			u32 eflags;
+		};
+		struct {
+			u16 di, hdi;
+			u16 si, hsi;
+			u16 bp, hbp;
+			u16 _sp, _hsp;
+			u16 bx, hbx;
+			u16 dx, hdx;
+			u16 cx, hcx;
+			u16 ax, hax;
+			u16 gs, fs;
+			u16 es, ds;
+			u16 flags, hflags;
+		};
+		struct {
+			u8 dil, dih, edi2, edi3;
+			u8 sil, sih, esi2, esi3;
+			u8 bpl, bph, ebp2, ebp3;
+			u8 _spl, _sph, _esp2, _esp3;
+			u8 bl, bh, ebx2, ebx3;
+			u8 dl, dh, edx2, edx3;
+			u8 cl, ch, ecx2, ecx3;
+			u8 al, ah, eax2, eax3;
+		};
+	};
+};
+void intcall(u8 int_no, const struct biosregs *ireg, struct biosregs *oreg);
+
+/* cmdline.c */
+int __cmdline_find_option(unsigned long cmdline_ptr, const char *option, char *buffer, int bufsize);
+int __cmdline_find_option_bool(unsigned long cmdline_ptr, const char *option);
+static inline int cmdline_find_option(const char *option, char *buffer, int bufsize)
+{
+	unsigned long cmd_line_ptr = boot_params.hdr.cmd_line_ptr;
+
+	if (cmd_line_ptr >= 0x100000)
+		return -1;      /* inaccessible */
+
+	return __cmdline_find_option(cmd_line_ptr, option, buffer, bufsize);
+}
+
+static inline int cmdline_find_option_bool(const char *option)
+{
+	unsigned long cmd_line_ptr = boot_params.hdr.cmd_line_ptr;
+
+	if (cmd_line_ptr >= 0x100000)
+		return -1;      /* inaccessible */
+
+	return __cmdline_find_option_bool(cmd_line_ptr, option);
+}
+
+/* cpu.c, cpucheck.c */
+int check_cpu(int *cpu_level_ptr, int *req_level_ptr, u32 **err_flags_ptr);
+int check_knl_erratum(void);
+int validate_cpu(void);
+
+/* early_serial_console.c */
+extern int early_serial_base;
+void console_init(void);
+
+/* edd.c */
+void query_edd(void);
+
+/* header.S */
+void __attribute__((noreturn)) die(void);
+
+/* memory.c */
+void detect_memory(void);
+
+/* pm.c */
+void __attribute__((noreturn)) go_to_protected_mode(void);
+
+/* pmjump.S */
+void __attribute__((noreturn))
+	protected_mode_jump(u32 entrypoint, u32 bootparams);
+
+/* printf.c */
+int sprintf(char *buf, const char *fmt, ...);
+int vsprintf(char *buf, const char *fmt, va_list args);
+int printf(const char *fmt, ...);
+
+/* regs.c */
+void initregs(struct biosregs *regs);
+
+/* string.c */
+int strcmp(const char *str1, const char *str2);
+int strncmp(const char *cs, const char *ct, size_t count);
+size_t strnlen(const char *s, size_t maxlen);
+unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base);
+size_t strlen(const char *s);
+char *strchr(const char *s, int c);
+
+/* tty.c */
+void puts(const char *);
+void putchar(int);
+int getchar(void);
+void kbd_flush(void);
+int getchar_timeout(void);
+
+/* video.c */
+void set_video(void);
+
+/* video-mode.c */
+int set_mode(u16 mode);
+int mode_defined(u16 mode);
+void probe_cards(int unsafe);
+
+/* video-vesa.c */
+void vesa_store_edid(void);
+
+#endif /* __ASSEMBLER__ */
+
+#endif /* BOOT_BOOT_H */

linux-7.2.3/arch/x86/boot/cmdline.c

@@ -0,0 +1,156 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Simple command-line parser for early boot.
+ */
+
+#include "boot.h"
+
+static inline int myisspace(u8 c)
+{
+	return c <= ' ';	/* Close enough approximation */
+}
+
+/*
+ * Find a non-boolean option, that is, "option=argument".  In accordance
+ * with standard Linux practice, if this option is repeated, this returns
+ * the last instance on the command line.
+ *
+ * Returns the length of the argument (regardless of if it was
+ * truncated to fit in the buffer), or -1 on not found.
+ */
+int __cmdline_find_option(unsigned long cmdline_ptr, const char *option, char *buffer, int bufsize)
+{
+	addr_t cptr;
+	char c;
+	int len = -1;
+	const char *opptr = NULL;
+	char *bufptr = buffer;
+	enum {
+		st_wordstart,	/* Start of word/after whitespace */
+		st_wordcmp,	/* Comparing this word */
+		st_wordskip,	/* Miscompare, skip */
+		st_bufcpy	/* Copying this to buffer */
+	} state = st_wordstart;
+
+	if (!cmdline_ptr)
+		return -1;      /* No command line */
+
+	cptr = cmdline_ptr & 0xf;
+	set_fs(cmdline_ptr >> 4);
+
+	while (cptr < 0x10000 && (c = rdfs8(cptr++))) {
+		switch (state) {
+		case st_wordstart:
+			if (myisspace(c))
+				break;
+
+			/* else */
+			state = st_wordcmp;
+			opptr = option;
+			fallthrough;
+
+		case st_wordcmp:
+			if (c == '=' && !*opptr) {
+				len = 0;
+				bufptr = buffer;
+				state = st_bufcpy;
+			} else if (myisspace(c)) {
+				state = st_wordstart;
+			} else if (c != *opptr++) {
+				state = st_wordskip;
+			}
+			break;
+
+		case st_wordskip:
+			if (myisspace(c))
+				state = st_wordstart;
+			break;
+
+		case st_bufcpy:
+			if (myisspace(c)) {
+				state = st_wordstart;
+			} else {
+				if (len < bufsize-1)
+					*bufptr++ = c;
+				len++;
+			}
+			break;
+		}
+	}
+
+	if (bufsize)
+		*bufptr = '\0';
+
+	return len;
+}
+
+/*
+ * Find a boolean option (like quiet,noapic,nosmp....)
+ *
+ * Returns the position of that option (starts counting with 1)
+ * or 0 on not found
+ */
+int __cmdline_find_option_bool(unsigned long cmdline_ptr, const char *option)
+{
+	addr_t cptr;
+	char c;
+	int pos = 0, wstart = 0;
+	const char *opptr = NULL;
+	enum {
+		st_wordstart,	/* Start of word/after whitespace */
+		st_wordcmp,	/* Comparing this word */
+		st_wordskip,	/* Miscompare, skip */
+	} state = st_wordstart;
+
+	if (!cmdline_ptr)
+		return -1;      /* No command line */
+
+	cptr = cmdline_ptr & 0xf;
+	set_fs(cmdline_ptr >> 4);
+
+	while (cptr < 0x10000) {
+		c = rdfs8(cptr++);
+		pos++;
+
+		switch (state) {
+		case st_wordstart:
+			if (!c)
+				return 0;
+			else if (myisspace(c))
+				break;
+
+			state = st_wordcmp;
+			opptr = option;
+			wstart = pos;
+			fallthrough;
+
+		case st_wordcmp:
+			if (!*opptr)
+				if (!c || myisspace(c))
+					return wstart;
+				else
+					state = st_wordskip;
+			else if (!c)
+				return 0;
+			else if (c != *opptr++)
+				state = st_wordskip;
+			break;
+
+		case st_wordskip:
+			if (!c)
+				return 0;
+			else if (myisspace(c))
+				state = st_wordstart;
+			break;
+		}
+	}
+
+	return 0;	/* Buffer overrun */
+}

linux-7.2.3/arch/x86/boot/compressed/.gitignore

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
+relocs
+vmlinux.bin.all
+vmlinux.relocs
+vmlinux.lds
+mkpiggy
+piggy.S

linux-7.2.3/arch/x86/boot/compressed/Makefile

@@ -0,0 +1,163 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# linux/arch/x86/boot/compressed/Makefile
+#
+# create a compressed vmlinux image from the original vmlinux
+#
+# vmlinuz is:
+#	decompression code (*.o)
+#	asm globals (piggy.S), including:
+#		vmlinux.bin.(gz|bz2|lzma|...)
+#
+# vmlinux.bin is:
+#	vmlinux stripped of debugging and comments
+# vmlinux.bin.all is:
+#	vmlinux.bin + vmlinux.relocs
+# vmlinux.bin.(gz|bz2|lzma|...) is:
+#	(see scripts/Makefile.lib size_append)
+#	compressed vmlinux.bin.all + u32 size of vmlinux.bin.all
+
+targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \
+	vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4 vmlinux.bin.zst
+
+# CLANG_FLAGS must come before any cc-disable-warning or cc-option calls in
+# case of cross compiling, as it has the '--target=' flag, which is needed to
+# avoid errors with '-march=i386', and future flags may depend on the target to
+# be valid.
+KBUILD_CFLAGS := -m$(BITS) -O2 $(CLANG_FLAGS)
+KBUILD_CFLAGS += $(CC_FLAGS_DIALECT)
+KBUILD_CFLAGS += -fno-strict-aliasing -fPIE
+KBUILD_CFLAGS += -fno-jump-tables
+KBUILD_CFLAGS += -Wundef
+KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
+cflags-$(CONFIG_X86_32) := -march=i386
+cflags-$(CONFIG_X86_64) := -mcmodel=small -mno-red-zone
+KBUILD_CFLAGS += $(cflags-y)
+KBUILD_CFLAGS += -mno-mmx -mno-sse
+KBUILD_CFLAGS += -ffreestanding -fshort-wchar
+KBUILD_CFLAGS += -fno-stack-protector
+KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
+KBUILD_CFLAGS += -Wno-pointer-sign
+KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
+KBUILD_CFLAGS += -D__DISABLE_EXPORTS
+# Disable relocation relaxation in case the link is not PIE.
+KBUILD_CFLAGS += $(call cc-option,-Wa$(comma)-mrelax-relocations=no)
+KBUILD_CFLAGS += -include $(srctree)/include/linux/hidden.h
+
+# sev-decode-insn.c indirectly includes inat-table.c which is generated during
+# compilation and stored in $(objtree). Add the directory to the includes so
+# that the compiler finds it even with out-of-tree builds (make O=/some/path).
+CFLAGS_sev-handle-vc.o += -I$(objtree)/arch/x86/lib/
+
+KBUILD_AFLAGS  := $(KBUILD_CFLAGS) -D__ASSEMBLY__
+
+KBUILD_LDFLAGS := -m elf_$(UTS_MACHINE)
+KBUILD_LDFLAGS += $(call ld-option,--no-ld-generated-unwind-info)
+# Compressed kernel should be built as PIE since it may be loaded at any
+# address by the bootloader.
+LDFLAGS_vmlinux := -pie $(call ld-option, --no-dynamic-linker)
+ifdef CONFIG_LD_ORPHAN_WARN
+LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
+endif
+LDFLAGS_vmlinux += -z noexecstack
+ifeq ($(CONFIG_LD_IS_BFD),y)
+LDFLAGS_vmlinux += $(call ld-option,--no-warn-rwx-segments)
+endif
+ifeq ($(CONFIG_EFI_STUB),y)
+# ensure that the static EFI stub library will be pulled in, even if it is
+# never referenced explicitly from the startup code
+LDFLAGS_vmlinux += -u efi_pe_entry
+endif
+LDFLAGS_vmlinux += -T
+
+hostprogs	:= mkpiggy
+HOST_EXTRACFLAGS += -I$(srctree)/tools/include
+
+sed-voffset := -e 's/^\([0-9a-fA-F]*\) [ABbCDGRSTtVW] \(_text\|__start_rodata\|_sinittext\|__inittext_end\|__bss_start\|_end\)$$/\#define VO_\2 _AC(0x\1,UL)/p'
+
+quiet_cmd_voffset = VOFFSET $@
+      cmd_voffset = $(NM) $< | sed -n $(sed-voffset) > $@
+
+targets += ../voffset.h
+
+$(obj)/../voffset.h: vmlinux FORCE
+	$(call if_changed,voffset)
+
+$(obj)/misc.o: $(obj)/../voffset.h
+
+vmlinux-objs-y := $(obj)/vmlinux.lds $(obj)/kernel_info.o $(obj)/head_$(BITS).o \
+	$(obj)/misc.o $(obj)/string.o $(obj)/cmdline.o $(obj)/error.o \
+	$(obj)/piggy.o $(obj)/cpuflags.o
+
+vmlinux-objs-$(CONFIG_EARLY_PRINTK) += $(obj)/early_serial_console.o
+vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr.o
+ifdef CONFIG_X86_64
+	vmlinux-objs-y += $(obj)/ident_map_64.o
+	vmlinux-objs-y += $(obj)/idt_64.o $(obj)/idt_handlers_64.o
+	vmlinux-objs-$(CONFIG_AMD_MEM_ENCRYPT) += $(obj)/mem_encrypt.o
+	vmlinux-objs-y += $(obj)/pgtable_64.o
+	vmlinux-objs-$(CONFIG_AMD_MEM_ENCRYPT) += $(obj)/sev.o $(obj)/sev-handle-vc.o
+endif
+
+vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o
+vmlinux-objs-$(CONFIG_INTEL_TDX_GUEST) += $(obj)/tdx.o $(obj)/tdcall.o $(obj)/tdx-shared.o
+vmlinux-objs-$(CONFIG_UNACCEPTED_MEMORY) += $(obj)/mem.o
+
+vmlinux-objs-$(CONFIG_EFI) += $(obj)/efi.o
+vmlinux-libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
+vmlinux-libs-$(CONFIG_X86_64)	+= $(objtree)/arch/x86/boot/startup/lib.a
+vmlinux-objs-$(CONFIG_EFI_SBAT) += $(obj)/sbat.o
+
+ifdef CONFIG_EFI_SBAT
+$(obj)/sbat.o: $(CONFIG_EFI_SBAT_FILE)
+AFLAGS_sbat.o += -I $(srctree)
+endif
+
+$(obj)/vmlinux: $(vmlinux-objs-y) $(vmlinux-libs-y) FORCE
+	$(call if_changed,ld)
+
+OBJCOPYFLAGS_vmlinux.bin :=  -R .comment -S
+$(obj)/vmlinux.bin: vmlinux FORCE
+	$(call if_changed,objcopy)
+
+targets += $(patsubst $(obj)/%,%,$(vmlinux-objs-y)) vmlinux.bin.all vmlinux.relocs
+
+CMD_RELOCS = arch/x86/tools/relocs
+quiet_cmd_relocs = RELOCS  $@
+      cmd_relocs = $(CMD_RELOCS) $< > $@;$(CMD_RELOCS) --abs-relocs $<
+
+$(obj)/vmlinux.relocs: vmlinux.unstripped FORCE
+	$(call if_changed,relocs)
+
+vmlinux.bin.all-y := $(obj)/vmlinux.bin
+vmlinux.bin.all-$(CONFIG_X86_NEED_RELOCS) += $(obj)/vmlinux.relocs
+
+$(obj)/vmlinux.bin.gz: $(vmlinux.bin.all-y) FORCE
+	$(call if_changed,gzip)
+$(obj)/vmlinux.bin.bz2: $(vmlinux.bin.all-y) FORCE
+	$(call if_changed,bzip2_with_size)
+$(obj)/vmlinux.bin.lzma: $(vmlinux.bin.all-y) FORCE
+	$(call if_changed,lzma_with_size)
+$(obj)/vmlinux.bin.xz: $(vmlinux.bin.all-y) FORCE
+	$(call if_changed,xzkern_with_size)
+$(obj)/vmlinux.bin.lzo: $(vmlinux.bin.all-y) FORCE
+	$(call if_changed,lzo_with_size)
+$(obj)/vmlinux.bin.lz4: $(vmlinux.bin.all-y) FORCE
+	$(call if_changed,lz4_with_size)
+$(obj)/vmlinux.bin.zst: $(vmlinux.bin.all-y) FORCE
+	$(call if_changed,zstd22_with_size)
+
+suffix-$(CONFIG_KERNEL_GZIP)	:= gz
+suffix-$(CONFIG_KERNEL_BZIP2)	:= bz2
+suffix-$(CONFIG_KERNEL_LZMA)	:= lzma
+suffix-$(CONFIG_KERNEL_XZ)	:= xz
+suffix-$(CONFIG_KERNEL_LZO) 	:= lzo
+suffix-$(CONFIG_KERNEL_LZ4) 	:= lz4
+suffix-$(CONFIG_KERNEL_ZSTD)	:= zst
+
+quiet_cmd_mkpiggy = MKPIGGY $@
+      cmd_mkpiggy = $(obj)/mkpiggy $< > $@
+
+targets += piggy.S
+$(obj)/piggy.S: $(obj)/vmlinux.bin.$(suffix-y) $(obj)/mkpiggy FORCE
+	$(call if_changed,mkpiggy)

linux-7.2.3/arch/x86/boot/compressed/acpi.c

@@ -0,0 +1,322 @@
+// SPDX-License-Identifier: GPL-2.0
+#define BOOT_CTYPE_H
+#include "misc.h"
+#include "error.h"
+#include "../string.h"
+#include "efi.h"
+
+#include <asm/bootparam.h>
+
+#include <linux/numa.h>
+
+/*
+ * Longest parameter of 'acpi=' is 'copy_dsdt', plus an extra '\0'
+ * for termination.
+ */
+#define MAX_ACPI_ARG_LENGTH 10
+
+/*
+ * Immovable memory regions representation. Max amount of memory regions is
+ * MAX_NUMNODES*2.
+ */
+struct mem_vector immovable_mem[MAX_NUMNODES*2];
+
+static acpi_physical_address
+__efi_get_rsdp_addr(unsigned long cfg_tbl_pa, unsigned int cfg_tbl_len)
+{
+#ifdef CONFIG_EFI
+	unsigned long rsdp_addr;
+	int ret;
+
+	/*
+	 * Search EFI system tables for RSDP. Preferred is ACPI_20_TABLE_GUID to
+	 * ACPI_TABLE_GUID because it has more features.
+	 */
+	rsdp_addr = efi_find_vendor_table(boot_params_ptr, cfg_tbl_pa, cfg_tbl_len,
+					  ACPI_20_TABLE_GUID);
+	if (rsdp_addr)
+		return (acpi_physical_address)rsdp_addr;
+
+	/* No ACPI_20_TABLE_GUID found, fallback to ACPI_TABLE_GUID. */
+	rsdp_addr = efi_find_vendor_table(boot_params_ptr, cfg_tbl_pa, cfg_tbl_len,
+					  ACPI_TABLE_GUID);
+	if (rsdp_addr)
+		return (acpi_physical_address)rsdp_addr;
+
+	debug_putstr("Error getting RSDP address.\n");
+#endif
+	return 0;
+}
+
+static acpi_physical_address efi_get_rsdp_addr(void)
+{
+#ifdef CONFIG_EFI
+	unsigned long cfg_tbl_pa = 0;
+	unsigned int cfg_tbl_len;
+	unsigned long systab_pa;
+	unsigned int nr_tables;
+	enum efi_type et;
+	int ret;
+
+	et = efi_get_type(boot_params_ptr);
+	if (et == EFI_TYPE_NONE)
+		return 0;
+
+	systab_pa = efi_get_system_table(boot_params_ptr);
+	if (!systab_pa)
+		error("EFI support advertised, but unable to locate system table.");
+
+	ret = efi_get_conf_table(boot_params_ptr, &cfg_tbl_pa, &cfg_tbl_len);
+	if (ret || !cfg_tbl_pa)
+		error("EFI config table not found.");
+
+	return __efi_get_rsdp_addr(cfg_tbl_pa, cfg_tbl_len);
+#else
+	return 0;
+#endif
+}
+
+static u8 compute_checksum(u8 *buffer, u32 length)
+{
+	u8 *end = buffer + length;
+	u8 sum = 0;
+
+	while (buffer < end)
+		sum += *(buffer++);
+
+	return sum;
+}
+
+/* Search a block of memory for the RSDP signature. */
+static u8 *scan_mem_for_rsdp(u8 *start, u32 length)
+{
+	struct acpi_table_rsdp *rsdp;
+	u8 *address, *end;
+
+	end = start + length;
+
+	/* Search from given start address for the requested length */
+	for (address = start; address < end; address += ACPI_RSDP_SCAN_STEP) {
+		/*
+		 * Both RSDP signature and checksum must be correct.
+		 * Note: Sometimes there exists more than one RSDP in memory;
+		 * the valid RSDP has a valid checksum, all others have an
+		 * invalid checksum.
+		 */
+		rsdp = (struct acpi_table_rsdp *)address;
+
+		/* BAD Signature */
+		if (!ACPI_VALIDATE_RSDP_SIG(rsdp->signature))
+			continue;
+
+		/* Check the standard checksum */
+		if (compute_checksum((u8 *)rsdp, ACPI_RSDP_CHECKSUM_LENGTH))
+			continue;
+
+		/* Check extended checksum if table version >= 2 */
+		if ((rsdp->revision >= 2) &&
+		    (compute_checksum((u8 *)rsdp, ACPI_RSDP_XCHECKSUM_LENGTH)))
+			continue;
+
+		/* Signature and checksum valid, we have found a real RSDP */
+		return address;
+	}
+	return NULL;
+}
+
+/* Search RSDP address in EBDA. */
+static acpi_physical_address bios_get_rsdp_addr(void)
+{
+	unsigned long address;
+	u8 *rsdp;
+
+	/* Get the location of the Extended BIOS Data Area (EBDA) */
+	address = *(u16 *)ACPI_EBDA_PTR_LOCATION;
+	address <<= 4;
+
+	/*
+	 * Search EBDA paragraphs (EBDA is required to be a minimum of
+	 * 1K length)
+	 */
+	if (address > 0x400) {
+		rsdp = scan_mem_for_rsdp((u8 *)address, ACPI_EBDA_WINDOW_SIZE);
+		if (rsdp)
+			return (acpi_physical_address)(unsigned long)rsdp;
+	}
+
+	/* Search upper memory: 16-byte boundaries in E0000h-FFFFFh */
+	rsdp = scan_mem_for_rsdp((u8 *) ACPI_HI_RSDP_WINDOW_BASE,
+					ACPI_HI_RSDP_WINDOW_SIZE);
+	if (rsdp)
+		return (acpi_physical_address)(unsigned long)rsdp;
+
+	return 0;
+}
+
+/* Return RSDP address on success, otherwise 0. */
+acpi_physical_address get_rsdp_addr(void)
+{
+	acpi_physical_address pa;
+
+	pa = boot_params_ptr->acpi_rsdp_addr;
+
+	if (!pa)
+		pa = efi_get_rsdp_addr();
+
+	if (!pa)
+		pa = bios_get_rsdp_addr();
+
+	return pa;
+}
+
+#if defined(CONFIG_RANDOMIZE_BASE) && defined(CONFIG_MEMORY_HOTREMOVE)
+/*
+ * Max length of 64-bit hex address string is 19, prefix "0x" + 16 hex
+ * digits, and '\0' for termination.
+ */
+#define MAX_ADDR_LEN 19
+
+static unsigned long get_cmdline_acpi_rsdp(void)
+{
+	unsigned long addr = 0;
+
+#ifdef CONFIG_KEXEC_CORE
+	char val[MAX_ADDR_LEN] = { };
+	int ret;
+
+	ret = cmdline_find_option("acpi_rsdp", val, sizeof(val));
+	if (ret < 0)
+		return 0;
+
+	if (ret >= sizeof(val)) {
+		warn("acpi_rsdp= value too long; ignoring");
+		return 0;
+	}
+
+	if (boot_kstrtoul(val, 16, &addr))
+		return 0;
+#endif
+	return addr;
+}
+
+/* Compute SRAT address from RSDP. */
+static unsigned long get_acpi_srat_table(void)
+{
+	unsigned long root_table, acpi_table;
+	struct acpi_table_header *header;
+	struct acpi_table_rsdp *rsdp;
+	u32 num_entries, size, len;
+	char arg[10];
+	u8 *entry;
+
+	/*
+	 * Check whether we were given an RSDP on the command line. We don't
+	 * stash this in boot params because the kernel itself may have
+	 * different ideas about whether to trust a command-line parameter.
+	 */
+	rsdp = (struct acpi_table_rsdp *)get_cmdline_acpi_rsdp();
+	if (!rsdp)
+		rsdp = (struct acpi_table_rsdp *)(long)
+			boot_params_ptr->acpi_rsdp_addr;
+
+	if (!rsdp)
+		return 0;
+
+	/* Get ACPI root table from RSDP.*/
+	if (!(cmdline_find_option("acpi", arg, sizeof(arg)) == 4 &&
+	    !strncmp(arg, "rsdt", 4)) &&
+	    rsdp->xsdt_physical_address &&
+	    rsdp->revision > 1) {
+		root_table = rsdp->xsdt_physical_address;
+		size = ACPI_XSDT_ENTRY_SIZE;
+	} else {
+		root_table = rsdp->rsdt_physical_address;
+		size = ACPI_RSDT_ENTRY_SIZE;
+	}
+
+	if (!root_table)
+		return 0;
+
+	header = (struct acpi_table_header *)root_table;
+	len = header->length;
+	if (len < sizeof(struct acpi_table_header) + size)
+		return 0;
+
+	num_entries = (len - sizeof(struct acpi_table_header)) / size;
+	entry = (u8 *)(root_table + sizeof(struct acpi_table_header));
+
+	while (num_entries--) {
+		if (size == ACPI_RSDT_ENTRY_SIZE)
+			acpi_table = *(u32 *)entry;
+		else
+			acpi_table = *(u64 *)entry;
+
+		if (acpi_table) {
+			header = (struct acpi_table_header *)acpi_table;
+
+			if (ACPI_COMPARE_NAMESEG(header->signature, ACPI_SIG_SRAT))
+				return acpi_table;
+		}
+		entry += size;
+	}
+	return 0;
+}
+
+/**
+ * count_immovable_mem_regions - Parse SRAT and cache the immovable
+ * memory regions into the immovable_mem array.
+ *
+ * Return the number of immovable memory regions on success, 0 on failure:
+ *
+ * - Too many immovable memory regions
+ * - ACPI off or no SRAT found
+ * - No immovable memory region found.
+ */
+int count_immovable_mem_regions(void)
+{
+	unsigned long table_addr, table_end, table;
+	struct acpi_subtable_header *sub_table;
+	struct acpi_table_header *table_header;
+	char arg[MAX_ACPI_ARG_LENGTH];
+	int num = 0;
+
+	if (cmdline_find_option("acpi", arg, sizeof(arg)) == 3 &&
+	    !strncmp(arg, "off", 3))
+		return 0;
+
+	table_addr = get_acpi_srat_table();
+	if (!table_addr)
+		return 0;
+
+	table_header = (struct acpi_table_header *)table_addr;
+	table_end = table_addr + table_header->length;
+	table = table_addr + sizeof(struct acpi_table_srat);
+
+	while (table + sizeof(struct acpi_subtable_header) < table_end) {
+
+		sub_table = (struct acpi_subtable_header *)table;
+		if (!sub_table->length) {
+			debug_putstr("Invalid zero length SRAT subtable.\n");
+			return 0;
+		}
+
+		if (sub_table->type == ACPI_SRAT_TYPE_MEMORY_AFFINITY) {
+			struct acpi_srat_mem_affinity *ma;
+
+			ma = (struct acpi_srat_mem_affinity *)sub_table;
+			if (!(ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE) && ma->length) {
+				immovable_mem[num].start = ma->base_address;
+				immovable_mem[num].size = ma->length;
+				num++;
+			}
+
+			if (num >= MAX_NUMNODES*2) {
+				debug_putstr("Too many immovable memory regions, aborting.\n");
+				return 0;
+			}
+		}
+		table += sub_table->length;
+	}
+	return num;
+}
+#endif /* CONFIG_RANDOMIZE_BASE && CONFIG_MEMORY_HOTREMOVE */

linux-7.2.3/arch/x86/boot/compressed/cmdline.c

@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "misc.h"
+
+#include <asm/bootparam.h>
+
+static unsigned long fs;
+static inline void set_fs(unsigned long seg)
+{
+	fs = seg << 4;  /* shift it back */
+}
+typedef unsigned long addr_t;
+static inline char rdfs8(addr_t addr)
+{
+	return *((char *)(fs + addr));
+}
+#include "../cmdline.c"
+unsigned long get_cmd_line_ptr(void)
+{
+	unsigned long cmd_line_ptr = boot_params_ptr->hdr.cmd_line_ptr;
+
+	cmd_line_ptr |= (u64)boot_params_ptr->ext_cmd_line_ptr << 32;
+
+	return cmd_line_ptr;
+}
+int cmdline_find_option(const char *option, char *buffer, int bufsize)
+{
+	return __cmdline_find_option(get_cmd_line_ptr(), option, buffer, bufsize);
+}
+int cmdline_find_option_bool(const char *option)
+{
+	return __cmdline_find_option_bool(get_cmd_line_ptr(), option);
+}

linux-7.2.3/arch/x86/boot/compressed/cpuflags.c

@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "../cpuflags.c"
+
+bool has_cpuflag(int flag)
+{
+	get_cpuflags();
+
+	return test_bit(flag, cpu.flags);
+}

linux-7.2.3/arch/x86/boot/compressed/early_serial_console.c

@@ -0,0 +1,6 @@
+#include "misc.h"
+
+/* This might be accessed before .bss is cleared, so use .data instead. */
+int early_serial_base __section(".data");
+
+#include "../early_serial_console.c"

linux-7.2.3/arch/x86/boot/compressed/efi.c

@@ -0,0 +1,236 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Helpers for early access to EFI configuration table.
+ *
+ * Originally derived from arch/x86/boot/compressed/acpi.c
+ */
+
+#include "misc.h"
+
+#include <asm/bootparam.h>
+
+/**
+ * efi_get_type - Given a pointer to boot_params, determine the type of EFI environment.
+ *
+ * @bp:         pointer to boot_params
+ *
+ * Return: EFI_TYPE_{32,64} for valid EFI environments, EFI_TYPE_NONE otherwise.
+ */
+enum efi_type efi_get_type(struct boot_params *bp)
+{
+	struct efi_info *ei;
+	enum efi_type et;
+	const char *sig;
+
+	ei = &bp->efi_info;
+	sig = (char *)&ei->efi_loader_signature;
+
+	if (!strncmp(sig, EFI64_LOADER_SIGNATURE, 4)) {
+		et = EFI_TYPE_64;
+	} else if (!strncmp(sig, EFI32_LOADER_SIGNATURE, 4)) {
+		et = EFI_TYPE_32;
+	} else {
+		debug_putstr("No EFI environment detected.\n");
+		et = EFI_TYPE_NONE;
+	}
+
+#ifndef CONFIG_X86_64
+	/*
+	 * Existing callers like acpi.c treat this case as an indicator to
+	 * fall-through to non-EFI, rather than an error, so maintain that
+	 * functionality here as well.
+	 */
+	if (ei->efi_systab_hi || ei->efi_memmap_hi) {
+		debug_putstr("EFI system table is located above 4GB and cannot be accessed.\n");
+		et = EFI_TYPE_NONE;
+	}
+#endif
+
+	return et;
+}
+
+/**
+ * efi_get_system_table - Given a pointer to boot_params, retrieve the physical address
+ *                        of the EFI system table.
+ *
+ * @bp:         pointer to boot_params
+ *
+ * Return: EFI system table address on success. On error, return 0.
+ */
+unsigned long efi_get_system_table(struct boot_params *bp)
+{
+	unsigned long sys_tbl_pa;
+	struct efi_info *ei;
+	enum efi_type et;
+
+	/* Get systab from boot params. */
+	ei = &bp->efi_info;
+#ifdef CONFIG_X86_64
+	sys_tbl_pa = ei->efi_systab | ((__u64)ei->efi_systab_hi << 32);
+#else
+	sys_tbl_pa = ei->efi_systab;
+#endif
+	if (!sys_tbl_pa) {
+		debug_putstr("EFI system table not found.");
+		return 0;
+	}
+
+	return sys_tbl_pa;
+}
+
+/*
+ * EFI config table address changes to virtual address after boot, which may
+ * not be accessible for the kexec'd kernel. To address this, kexec provides
+ * the initial physical address via a struct setup_data entry, which is
+ * checked for here, along with some sanity checks.
+ */
+static struct efi_setup_data *get_kexec_setup_data(struct boot_params *bp,
+						   enum efi_type et)
+{
+#ifdef CONFIG_X86_64
+	struct efi_setup_data *esd = NULL;
+	struct setup_data *data;
+	u64 pa_data;
+
+	pa_data = bp->hdr.setup_data;
+	while (pa_data) {
+		data = (struct setup_data *)pa_data;
+		if (data->type == SETUP_EFI) {
+			esd = (struct efi_setup_data *)(pa_data + sizeof(struct setup_data));
+			break;
+		}
+
+		pa_data = data->next;
+	}
+
+	/*
+	 * Original ACPI code falls back to attempting normal EFI boot in these
+	 * cases, so maintain existing behavior by indicating non-kexec
+	 * environment to the caller, but print them for debugging.
+	 */
+	if (esd && !esd->tables) {
+		debug_putstr("kexec EFI environment missing valid configuration table.\n");
+		return NULL;
+	}
+
+	return esd;
+#endif
+	return NULL;
+}
+
+/**
+ * efi_get_conf_table - Given a pointer to boot_params, locate and return the physical
+ *                      address of EFI configuration table.
+ *
+ * @bp:                 pointer to boot_params
+ * @cfg_tbl_pa:         location to store physical address of config table
+ * @cfg_tbl_len:        location to store number of config table entries
+ *
+ * Return: 0 on success. On error, return params are left unchanged.
+ */
+int efi_get_conf_table(struct boot_params *bp, unsigned long *cfg_tbl_pa,
+		       unsigned int *cfg_tbl_len)
+{
+	unsigned long sys_tbl_pa;
+	enum efi_type et;
+	int ret;
+
+	if (!cfg_tbl_pa || !cfg_tbl_len)
+		return -EINVAL;
+
+	sys_tbl_pa = efi_get_system_table(bp);
+	if (!sys_tbl_pa)
+		return -EINVAL;
+
+	/* Handle EFI bitness properly */
+	et = efi_get_type(bp);
+	if (et == EFI_TYPE_64) {
+		efi_system_table_64_t *stbl = (efi_system_table_64_t *)sys_tbl_pa;
+		struct efi_setup_data *esd;
+
+		/* kexec provides an alternative EFI conf table, check for it. */
+		esd = get_kexec_setup_data(bp, et);
+
+		*cfg_tbl_pa = esd ? esd->tables : stbl->tables;
+		*cfg_tbl_len = stbl->nr_tables;
+	} else if (et == EFI_TYPE_32) {
+		efi_system_table_32_t *stbl = (efi_system_table_32_t *)sys_tbl_pa;
+
+		*cfg_tbl_pa = stbl->tables;
+		*cfg_tbl_len = stbl->nr_tables;
+	} else {
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/* Get vendor table address/guid from EFI config table at the given index */
+static int get_vendor_table(void *cfg_tbl, unsigned int idx,
+			    unsigned long *vendor_tbl_pa,
+			    efi_guid_t *vendor_tbl_guid,
+			    enum efi_type et)
+{
+	if (et == EFI_TYPE_64) {
+		efi_config_table_64_t *tbl_entry = (efi_config_table_64_t *)cfg_tbl + idx;
+
+		if (!IS_ENABLED(CONFIG_X86_64) && tbl_entry->table >> 32) {
+			debug_putstr("Error: EFI config table entry located above 4GB.\n");
+			return -EINVAL;
+		}
+
+		*vendor_tbl_pa = tbl_entry->table;
+		*vendor_tbl_guid = tbl_entry->guid;
+
+	} else if (et == EFI_TYPE_32) {
+		efi_config_table_32_t *tbl_entry = (efi_config_table_32_t *)cfg_tbl + idx;
+
+		*vendor_tbl_pa = tbl_entry->table;
+		*vendor_tbl_guid = tbl_entry->guid;
+	} else {
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * efi_find_vendor_table - Given EFI config table, search it for the physical
+ *                         address of the vendor table associated with GUID.
+ *
+ * @bp:                pointer to boot_params
+ * @cfg_tbl_pa:        pointer to EFI configuration table
+ * @cfg_tbl_len:       number of entries in EFI configuration table
+ * @guid:              GUID of vendor table
+ *
+ * Return: vendor table address on success. On error, return 0.
+ */
+unsigned long efi_find_vendor_table(struct boot_params *bp,
+				    unsigned long cfg_tbl_pa,
+				    unsigned int cfg_tbl_len,
+				    efi_guid_t guid)
+{
+	enum efi_type et;
+	unsigned int i;
+
+	et = efi_get_type(bp);
+	if (et == EFI_TYPE_NONE)
+		return 0;
+
+	for (i = 0; i < cfg_tbl_len; i++) {
+		unsigned long vendor_tbl_pa;
+		efi_guid_t vendor_tbl_guid;
+		int ret;
+
+		ret = get_vendor_table((void *)cfg_tbl_pa, i,
+				       &vendor_tbl_pa,
+				       &vendor_tbl_guid, et);
+		if (ret)
+			return 0;
+
+		if (!efi_guidcmp(guid, vendor_tbl_guid))
+			return vendor_tbl_pa;
+	}
+
+	return 0;
+}

linux-7.2.3/arch/x86/boot/compressed/efi.h

@@ -0,0 +1,127 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BOOT_COMPRESSED_EFI_H
+#define BOOT_COMPRESSED_EFI_H
+
+#if defined(_LINUX_EFI_H) || defined(_ASM_X86_EFI_H)
+#error Please do not include kernel proper namespace headers
+#endif
+
+typedef guid_t efi_guid_t __aligned(__alignof__(u32));
+
+#define EFI_GUID(a, b, c, d...) (efi_guid_t){ {					\
+	(a) & 0xff, ((a) >> 8) & 0xff, ((a) >> 16) & 0xff, ((a) >> 24) & 0xff,	\
+	(b) & 0xff, ((b) >> 8) & 0xff,						\
+	(c) & 0xff, ((c) >> 8) & 0xff, d } }
+
+#define ACPI_TABLE_GUID				EFI_GUID(0xeb9d2d30, 0x2d88, 0x11d3,  0x9a, 0x16, 0x00, 0x90, 0x27, 0x3f, 0xc1, 0x4d)
+#define ACPI_20_TABLE_GUID			EFI_GUID(0x8868e871, 0xe4f1, 0x11d3,  0xbc, 0x22, 0x00, 0x80, 0xc7, 0x3c, 0x88, 0x81)
+#define EFI_CC_BLOB_GUID			EFI_GUID(0x067b1f5f, 0xcf26, 0x44c5, 0x85, 0x54, 0x93, 0xd7, 0x77, 0x91, 0x2d, 0x42)
+#define LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID	EFI_GUID(0xd5d1de3c, 0x105c, 0x44f9,  0x9e, 0xa9, 0xbc, 0xef, 0x98, 0x12, 0x00, 0x31)
+
+#define EFI32_LOADER_SIGNATURE	"EL32"
+#define EFI64_LOADER_SIGNATURE	"EL64"
+
+/*
+ * Generic EFI table header
+ */
+typedef	struct {
+	u64 signature;
+	u32 revision;
+	u32 headersize;
+	u32 crc32;
+	u32 reserved;
+} efi_table_hdr_t;
+
+#define EFI_CONVENTIONAL_MEMORY		 7
+#define EFI_UNACCEPTED_MEMORY		15
+
+#define EFI_MEMORY_MORE_RELIABLE \
+				((u64)0x0000000000010000ULL)	/* higher reliability */
+#define EFI_MEMORY_SP		((u64)0x0000000000040000ULL)	/* soft reserved */
+
+#define EFI_PAGE_SHIFT		12
+
+typedef struct {
+	u32 type;
+	u32 pad;
+	u64 phys_addr;
+	u64 virt_addr;
+	u64 num_pages;
+	u64 attribute;
+} efi_memory_desc_t;
+
+#define efi_early_memdesc_ptr(map, desc_size, n)			\
+	(efi_memory_desc_t *)((void *)(map) + ((n) * (desc_size)))
+
+typedef struct {
+	efi_guid_t guid;
+	u64 table;
+} efi_config_table_64_t;
+
+typedef struct {
+	efi_guid_t guid;
+	u32 table;
+} efi_config_table_32_t;
+
+typedef struct {
+	efi_table_hdr_t hdr;
+	u64 fw_vendor;	/* physical addr of CHAR16 vendor string */
+	u32 fw_revision;
+	u32 __pad1;
+	u64 con_in_handle;
+	u64 con_in;
+	u64 con_out_handle;
+	u64 con_out;
+	u64 stderr_handle;
+	u64 stderr;
+	u64 runtime;
+	u64 boottime;
+	u32 nr_tables;
+	u32 __pad2;
+	u64 tables;
+} efi_system_table_64_t;
+
+typedef struct {
+	efi_table_hdr_t hdr;
+	u32 fw_vendor;	/* physical addr of CHAR16 vendor string */
+	u32 fw_revision;
+	u32 con_in_handle;
+	u32 con_in;
+	u32 con_out_handle;
+	u32 con_out;
+	u32 stderr_handle;
+	u32 stderr;
+	u32 runtime;
+	u32 boottime;
+	u32 nr_tables;
+	u32 tables;
+} efi_system_table_32_t;
+
+struct efi_unaccepted_memory {
+	u32 version;
+	u32 unit_size;
+	u64 phys_base;
+	u64 size;
+	unsigned long bitmap[];
+};
+
+static inline int efi_guidcmp (efi_guid_t left, efi_guid_t right)
+{
+	return memcmp(&left, &right, sizeof (efi_guid_t));
+}
+
+#ifdef CONFIG_EFI
+bool __pure __efi_soft_reserve_enabled(void);
+
+static inline bool __pure efi_soft_reserve_enabled(void)
+{
+	return IS_ENABLED(CONFIG_EFI_SOFT_RESERVE)
+		&& __efi_soft_reserve_enabled();
+}
+#else
+static inline bool efi_soft_reserve_enabled(void)
+{
+	return false;
+}
+#endif /* CONFIG_EFI */
+#endif /* BOOT_COMPRESSED_EFI_H */

linux-7.2.3/arch/x86/boot/compressed/error.c

@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Callers outside of misc.c need access to the error reporting routines,
+ * but the *_putstr() functions need to stay in misc.c because of how
+ * memcpy() and memmove() are defined for the compressed boot environment.
+ */
+#include "misc.h"
+#include "error.h"
+
+void warn(const char *m)
+{
+	error_putstr("\n\n");
+	error_putstr(m);
+	error_putstr("\n\n");
+}
+
+void error(char *m)
+{
+	warn(m);
+	error_putstr(" -- System halted");
+
+	while (1)
+		asm("hlt");
+}
+
+/* EFI libstub  provides vsnprintf() */
+#ifdef CONFIG_EFI_STUB
+void panic(const char *fmt, ...)
+{
+	static char buf[1024];
+	va_list args;
+	int len;
+
+	va_start(args, fmt);
+	len = vsnprintf(buf, sizeof(buf), fmt, args);
+	va_end(args);
+
+	if (len && buf[len - 1] == '\n')
+		buf[len - 1] = '\0';
+
+	error(buf);
+}
+#endif

linux-7.2.3/arch/x86/boot/compressed/error.h

@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BOOT_COMPRESSED_ERROR_H
+#define BOOT_COMPRESSED_ERROR_H
+
+#include <linux/compiler.h>
+
+void warn(const char *m);
+void error(char *m) __noreturn;
+void panic(const char *fmt, ...) __noreturn __cold;
+
+#endif /* BOOT_COMPRESSED_ERROR_H */

linux-7.2.3/arch/x86/boot/compressed/head_32.S

@@ -0,0 +1,188 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  linux/boot/head.S
+ *
+ *  Copyright (C) 1991, 1992, 1993  Linus Torvalds
+ */
+
+/*
+ *  head.S contains the 32-bit startup code.
+ *
+ * NOTE!!! Startup happens at absolute address 0x00001000, which is also where
+ * the page directory will exist. The startup code will be overwritten by
+ * the page directory. [According to comments etc elsewhere on a compressed
+ * kernel it will end up at 0x1000 + 1Mb I hope so as I assume this. - AC]
+ *
+ * Page 0 is deliberately kept safe, since System Management Mode code in
+ * laptops may need to access the BIOS data stored there.  This is also
+ * useful for future device drivers that either access the BIOS via VM86
+ * mode.
+ */
+
+/*
+ * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
+ */
+	.text
+
+#include <linux/init.h>
+#include <linux/linkage.h>
+#include <asm/segment.h>
+#include <asm/page_types.h>
+#include <asm/boot.h>
+#include <asm/asm-offsets.h>
+#include <asm/bootparam.h>
+
+/*
+ * These symbols needed to be marked as .hidden to prevent the BFD linker from
+ * generating R_386_32 (rather than R_386_RELATIVE) relocations for them when
+ * the 32-bit compressed kernel is linked as PIE. This is no longer necessary,
+ * but it doesn't hurt to keep them .hidden.
+ */
+	.hidden _bss
+	.hidden _ebss
+	.hidden _end
+
+	__HEAD
+SYM_FUNC_START(startup_32)
+	cld
+	cli
+
+/*
+ * Calculate the delta between where we were compiled to run
+ * at and where we were actually loaded at.  This can only be done
+ * with a short local call on x86.  Nothing  else will tell us what
+ * address we are running at.  The reserved chunk of the real-mode
+ * data at 0x1e4 (defined as a scratch field) are used as the stack
+ * for this calculation. Only 4 bytes are needed.
+ */
+	leal	(BP_scratch+4)(%esi), %esp
+	call	1f
+1:	popl	%edx
+	addl	$_GLOBAL_OFFSET_TABLE_+(.-1b), %edx
+
+	/* Load new GDT */
+	leal	gdt@GOTOFF(%edx), %eax
+	movl	%eax, 2(%eax)
+	lgdt	(%eax)
+
+	/* Load segment registers with our descriptors */
+	movl	$__BOOT_DS, %eax
+	movl	%eax, %ds
+	movl	%eax, %es
+	movl	%eax, %fs
+	movl	%eax, %gs
+	movl	%eax, %ss
+
+/*
+ * %edx contains the address we are loaded at by the boot loader (plus the
+ * offset to the GOT).  The below code calculates %ebx to be the address where
+ * we should move the kernel image temporarily for safe in-place decompression
+ * (again, plus the offset to the GOT).
+ *
+ * %ebp is calculated to be the address that the kernel will be decompressed to.
+ */
+
+#ifdef CONFIG_RELOCATABLE
+	leal	startup_32@GOTOFF(%edx), %ebx
+	movl	BP_kernel_alignment(%esi), %eax
+	decl	%eax
+	addl    %eax, %ebx
+	notl	%eax
+	andl    %eax, %ebx
+	cmpl	$LOAD_PHYSICAL_ADDR, %ebx
+	jae	1f
+#endif
+	movl	$LOAD_PHYSICAL_ADDR, %ebx
+1:
+
+	movl	%ebx, %ebp	// Save the output address for later
+	/* Target address to relocate to for decompression */
+	addl    BP_init_size(%esi), %ebx
+	subl    $_end@GOTOFF, %ebx
+
+	/* Set up the stack */
+	leal	boot_stack_end@GOTOFF(%ebx), %esp
+
+	/* Zero EFLAGS */
+	pushl	$0
+	popfl
+
+/*
+ * Copy the compressed kernel to the end of our buffer
+ * where decompression in place becomes safe.
+ */
+	pushl	%esi
+	leal	(_bss@GOTOFF-4)(%edx), %esi
+	leal	(_bss@GOTOFF-4)(%ebx), %edi
+	movl	$(_bss - startup_32), %ecx
+	shrl	$2, %ecx
+	std
+	rep	movsl
+	cld
+	popl	%esi
+
+	/*
+	 * The GDT may get overwritten either during the copy we just did or
+	 * during extract_kernel below. To avoid any issues, repoint the GDTR
+	 * to the new copy of the GDT.
+	 */
+	leal	gdt@GOTOFF(%ebx), %eax
+	movl	%eax, 2(%eax)
+	lgdt	(%eax)
+
+/*
+ * Jump to the relocated address.
+ */
+	leal	.Lrelocated@GOTOFF(%ebx), %eax
+	jmp	*%eax
+SYM_FUNC_END(startup_32)
+
+	.text
+SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated)
+
+/*
+ * Clear BSS (stack is currently empty)
+ */
+	xorl	%eax, %eax
+	leal	_bss@GOTOFF(%ebx), %edi
+	leal	_ebss@GOTOFF(%ebx), %ecx
+	subl	%edi, %ecx
+	shrl	$2, %ecx
+	rep	stosl
+
+/*
+ * Do the extraction, and jump to the new kernel..
+ */
+	/* push arguments for extract_kernel: */
+
+	pushl	%ebp			/* output address */
+	pushl	%esi			/* real mode pointer */
+	call	extract_kernel		/* returns kernel entry point in %eax */
+	addl	$24, %esp
+
+/*
+ * Jump to the extracted kernel.
+ */
+	xorl	%ebx, %ebx
+	jmp	*%eax
+SYM_FUNC_END(.Lrelocated)
+
+	.data
+	.balign	8
+SYM_DATA_START_LOCAL(gdt)
+	.word	gdt_end - gdt - 1
+	.long	0
+	.word	0
+	.quad	0x0000000000000000	/* Reserved */
+	.quad	0x00cf9a000000ffff	/* __KERNEL_CS */
+	.quad	0x00cf92000000ffff	/* __KERNEL_DS */
+SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end)
+
+/*
+ * Stack and heap for uncompression
+ */
+	.bss
+	.balign 4
+boot_stack:
+	.fill BOOT_STACK_SIZE, 1, 0
+boot_stack_end:

linux-7.2.3/arch/x86/boot/compressed/head_64.S

@@ -0,0 +1,539 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  linux/boot/head.S
+ *
+ *  Copyright (C) 1991, 1992, 1993  Linus Torvalds
+ */
+
+/*
+ *  head.S contains the 32-bit startup code.
+ *
+ * NOTE!!! Startup happens at absolute address 0x00001000, which is also where
+ * the page directory will exist. The startup code will be overwritten by
+ * the page directory. [According to comments etc elsewhere on a compressed
+ * kernel it will end up at 0x1000 + 1Mb I hope so as I assume this. - AC]
+ *
+ * Page 0 is deliberately kept safe, since System Management Mode code in 
+ * laptops may need to access the BIOS data stored there.  This is also
+ * useful for future device drivers that either access the BIOS via VM86 
+ * mode.
+ */
+
+/*
+ * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
+ */
+	.code32
+	.text
+
+#include <linux/init.h>
+#include <linux/linkage.h>
+#include <asm/segment.h>
+#include <asm/boot.h>
+#include <asm/msr.h>
+#include <asm/processor-flags.h>
+#include <asm/asm-offsets.h>
+#include <asm/bootparam.h>
+#include <asm/desc_defs.h>
+#include <asm/trapnr.h>
+
+/*
+ * Fix alignment at 16 bytes. Following CONFIG_FUNCTION_ALIGNMENT will result
+ * in assembly errors due to trying to move .org backward due to the excessive
+ * alignment.
+ */
+#undef __ALIGN
+#define __ALIGN		.balign	16, 0x90
+
+/*
+ * Locally defined symbols should be marked hidden:
+ */
+	.hidden _bss
+	.hidden _ebss
+	.hidden _end
+
+	__HEAD
+
+/*
+ * This macro gives the relative virtual address of X, i.e. the offset of X
+ * from startup_32. This is the same as the link-time virtual address of X,
+ * since startup_32 is at 0, but defining it this way tells the
+ * assembler/linker that we do not want the actual run-time address of X. This
+ * prevents the linker from trying to create unwanted run-time relocation
+ * entries for the reference when the compressed kernel is linked as PIE.
+ *
+ * A reference X(%reg) will result in the link-time VA of X being stored with
+ * the instruction, and a run-time R_X86_64_RELATIVE relocation entry that
+ * adds the 64-bit base address where the kernel is loaded.
+ *
+ * Replacing it with (X-startup_32)(%reg) results in the offset being stored,
+ * and no run-time relocation.
+ *
+ * The macro should be used as a displacement with a base register containing
+ * the run-time address of startup_32 [i.e. rva(X)(%reg)], or as an immediate
+ * [$ rva(X)].
+ *
+ * This macro can only be used from within the .head.text section, since the
+ * expression requires startup_32 to be in the same section as the code being
+ * assembled.
+ */
+#define rva(X) ((X) - startup_32)
+
+	.code32
+SYM_FUNC_START(startup_32)
+	/*
+	 * 32bit entry is 0 and it is ABI so immutable!
+	 * If we come here directly from a bootloader,
+	 * kernel(text+data+bss+brk) ramdisk, zero_page, command line
+	 * all need to be under the 4G limit.
+	 */
+	cld
+	cli
+
+/*
+ * Calculate the delta between where we were compiled to run
+ * at and where we were actually loaded at.  This can only be done
+ * with a short local call on x86.  Nothing  else will tell us what
+ * address we are running at.  The reserved chunk of the real-mode
+ * data at 0x1e4 (defined as a scratch field) are used as the stack
+ * for this calculation. Only 4 bytes are needed.
+ */
+	leal	(BP_scratch+4)(%esi), %esp
+	call	1f
+1:	popl	%ebp
+	subl	$ rva(1b), %ebp
+
+	/* Load new GDT with the 64bit segments using 32bit descriptor */
+	leal	rva(gdt)(%ebp), %eax
+	movl	%eax, 2(%eax)
+	lgdt	(%eax)
+
+	/* Load segment registers with our descriptors */
+	movl	$__BOOT_DS, %eax
+	movl	%eax, %ds
+	movl	%eax, %es
+	movl	%eax, %fs
+	movl	%eax, %gs
+	movl	%eax, %ss
+
+	/* Setup a stack and load CS from current GDT */
+	leal	rva(boot_stack_end)(%ebp), %esp
+
+	pushl	$__KERNEL32_CS
+	leal	rva(1f)(%ebp), %eax
+	pushl	%eax
+	lretl
+1:
+
+	/* Setup Exception handling for SEV-ES */
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+	call	startup32_load_idt
+#endif
+
+	/* Make sure cpu supports long mode. */
+	call	verify_cpu
+	testl	%eax, %eax
+	jnz	.Lno_longmode
+
+/*
+ * Compute the delta between where we were compiled to run at
+ * and where the code will actually run at.
+ *
+ * %ebp contains the address we are loaded at by the boot loader and %ebx
+ * contains the address where we should move the kernel image temporarily
+ * for safe in-place decompression.
+ */
+
+#ifdef CONFIG_RELOCATABLE
+	movl	%ebp, %ebx
+	movl	BP_kernel_alignment(%esi), %eax
+	decl	%eax
+	addl	%eax, %ebx
+	notl	%eax
+	andl	%eax, %ebx
+	cmpl	$LOAD_PHYSICAL_ADDR, %ebx
+	jae	1f
+#endif
+	movl	$LOAD_PHYSICAL_ADDR, %ebx
+1:
+
+	/* Target address to relocate to for decompression */
+	addl	BP_init_size(%esi), %ebx
+	subl	$ rva(_end), %ebx
+
+/*
+ * Prepare for entering 64 bit mode
+ */
+
+	/* Enable PAE mode */
+	movl	%cr4, %eax
+	orl	$X86_CR4_PAE, %eax
+	movl	%eax, %cr4
+
+ /*
+  * Build early 4G boot pagetable
+  */
+	/*
+	 * If SEV is active then set the encryption mask in the page tables.
+	 * This will ensure that when the kernel is copied and decompressed
+	 * it will be done so encrypted.
+	 */
+	xorl	%edx, %edx
+#ifdef	CONFIG_AMD_MEM_ENCRYPT
+	call	get_sev_encryption_bit
+	xorl	%edx, %edx
+	testl	%eax, %eax
+	jz	1f
+	subl	$32, %eax	/* Encryption bit is always above bit 31 */
+	bts	%eax, %edx	/* Set encryption mask for page tables */
+	/*
+	 * Set MSR_AMD64_SEV_ENABLED_BIT in sev_status so that
+	 * startup32_check_sev_cbit() will do a check. sev_enable() will
+	 * initialize sev_status with all the bits reported by
+	 * MSR_AMD_SEV_STATUS later, but only MSR_AMD64_SEV_ENABLED_BIT
+	 * needs to be set for now.
+	 */
+	movl	$1, rva(sev_status)(%ebp)
+1:
+#endif
+
+	/* Initialize Page tables to 0 */
+	leal	rva(pgtable)(%ebx), %edi
+	xorl	%eax, %eax
+	movl	$(BOOT_INIT_PGT_SIZE/4), %ecx
+	rep	stosl
+
+	/* Build Level 4 */
+	leal	rva(pgtable + 0)(%ebx), %edi
+	leal	0x1007 (%edi), %eax
+	movl	%eax, 0(%edi)
+	addl	%edx, 4(%edi)
+
+	/* Build Level 3 */
+	leal	rva(pgtable + 0x1000)(%ebx), %edi
+	leal	0x1007(%edi), %eax
+	movl	$4, %ecx
+1:	movl	%eax, 0x00(%edi)
+	addl	%edx, 0x04(%edi)
+	addl	$0x00001000, %eax
+	addl	$8, %edi
+	decl	%ecx
+	jnz	1b
+
+	/* Build Level 2 */
+	leal	rva(pgtable + 0x2000)(%ebx), %edi
+	movl	$0x00000183, %eax
+	movl	$2048, %ecx
+1:	movl	%eax, 0(%edi)
+	addl	%edx, 4(%edi)
+	addl	$0x00200000, %eax
+	addl	$8, %edi
+	decl	%ecx
+	jnz	1b
+
+	/* Enable the boot page tables */
+	leal	rva(pgtable)(%ebx), %eax
+	movl	%eax, %cr3
+
+	/* Enable Long mode in EFER (Extended Feature Enable Register) */
+	movl	$MSR_EFER, %ecx
+	rdmsr
+	btsl	$_EFER_LME, %eax
+	wrmsr
+
+	/* After gdt is loaded */
+	xorl	%eax, %eax
+	lldt	%ax
+	movl    $__BOOT_TSS, %eax
+	ltr	%ax
+
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+	/* Check if the C-bit position is correct when SEV is active */
+	call	startup32_check_sev_cbit
+#endif
+
+	/*
+	 * Setup for the jump to 64bit mode
+	 *
+	 * When the jump is performed we will be in long mode but
+	 * in 32bit compatibility mode with EFER.LME = 1, CS.L = 0, CS.D = 1
+	 * (and in turn EFER.LMA = 1).	To jump into 64bit mode we use
+	 * the new gdt/idt that has __KERNEL_CS with CS.L = 1.
+	 * We place all of the values on our mini stack so lret can
+	 * used to perform that far jump.
+	 */
+	leal	rva(startup_64)(%ebp), %eax
+	pushl	$__KERNEL_CS
+	pushl	%eax
+
+	/* Enter paged protected Mode, activating Long Mode */
+	movl	$CR0_STATE, %eax
+	movl	%eax, %cr0
+
+	/* Jump from 32bit compatibility mode into 64bit mode. */
+	lret
+SYM_FUNC_END(startup_32)
+
+	.code64
+	.org 0x200
+SYM_CODE_START(startup_64)
+	/*
+	 * 64bit entry is 0x200 and it is ABI so immutable!
+	 * We come here either from startup_32 or directly from a
+	 * 64bit bootloader.
+	 * If we come here from a bootloader, kernel(text+data+bss+brk),
+	 * ramdisk, zero_page, command line could be above 4G.
+	 * We depend on an identity mapped page table being provided
+	 * that maps our entire kernel(text+data+bss+brk), zero page
+	 * and command line.
+	 */
+
+	cld
+	cli
+
+	/* Setup data segments. */
+	xorl	%eax, %eax
+	movl	%eax, %ds
+	movl	%eax, %es
+	movl	%eax, %ss
+	movl	%eax, %fs
+	movl	%eax, %gs
+
+	/*
+	 * Compute the decompressed kernel start address.  It is where
+	 * we were loaded at aligned to a 2M boundary. %rbp contains the
+	 * decompressed kernel start address.
+	 *
+	 * If it is a relocatable kernel then decompress and run the kernel
+	 * from load address aligned to 2MB addr, otherwise decompress and
+	 * run the kernel from LOAD_PHYSICAL_ADDR
+	 *
+	 * We cannot rely on the calculation done in 32-bit mode, since we
+	 * may have been invoked via the 64-bit entry point.
+	 */
+
+	/* Start with the delta to where the kernel will run at. */
+#ifdef CONFIG_RELOCATABLE
+	leaq	startup_32(%rip) /* - $startup_32 */, %rbp
+	movl	BP_kernel_alignment(%rsi), %eax
+	decl	%eax
+	addq	%rax, %rbp
+	notq	%rax
+	andq	%rax, %rbp
+	cmpq	$LOAD_PHYSICAL_ADDR, %rbp
+	jae	1f
+#endif
+	movq	$LOAD_PHYSICAL_ADDR, %rbp
+1:
+
+	/* Target address to relocate to for decompression */
+	movl	BP_init_size(%rsi), %ebx
+	subl	$ rva(_end), %ebx
+	addq	%rbp, %rbx
+
+	/* Set up the stack */
+	leaq	rva(boot_stack_end)(%rbx), %rsp
+
+	/*
+	 * At this point we are in long mode with 4-level paging enabled,
+	 * but we might want to enable 5-level paging or vice versa.
+	 *
+	 * The problem is that we cannot do it directly. Setting or clearing
+	 * CR4.LA57 in long mode would trigger #GP. So we need to switch off
+	 * long mode and paging first.
+	 *
+	 * We also need a trampoline in lower memory to switch over from
+	 * 4- to 5-level paging for cases when the bootloader puts the kernel
+	 * above 4G, but didn't enable 5-level paging for us.
+	 *
+	 * The same trampoline can be used to switch from 5- to 4-level paging
+	 * mode, like when starting 4-level paging kernel via kexec() when
+	 * original kernel worked in 5-level paging mode.
+	 *
+	 * For the trampoline, we need the top page table to reside in lower
+	 * memory as we don't have a way to load 64-bit values into CR3 in
+	 * 32-bit mode.
+	 */
+
+	/* Make sure we have GDT with 32-bit code segment */
+	leaq	gdt64(%rip), %rax
+	addq	%rax, 2(%rax)
+	lgdt	(%rax)
+
+	/* Reload CS so IRET returns to a CS actually in the GDT */
+	pushq	$__KERNEL_CS
+	leaq	.Lon_kernel_cs(%rip), %rax
+	pushq	%rax
+	lretq
+
+.Lon_kernel_cs:
+	/*
+	 * RSI holds a pointer to a boot_params structure provided by the
+	 * loader, and this needs to be preserved across C function calls. So
+	 * move it into a callee saved register.
+	 */
+	movq	%rsi, %r15
+
+	call	load_stage1_idt
+
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+	/*
+	 * Now that the stage1 interrupt handlers are set up, #VC exceptions from
+	 * CPUID instructions can be properly handled for SEV-ES guests.
+	 *
+	 * For SEV-SNP, the CPUID table also needs to be set up in advance of any
+	 * CPUID instructions being issued, so go ahead and do that now via
+	 * sev_enable(), which will also handle the rest of the SEV-related
+	 * detection/setup to ensure that has been done in advance of any dependent
+	 * code. Pass the boot_params pointer as the first argument.
+	 */
+	movq	%r15, %rdi
+	call	sev_enable
+#endif
+
+	/* Preserve only the CR4 bits that must be preserved, and clear the rest */
+	movq	%cr4, %rax
+	andl	$(X86_CR4_PAE | X86_CR4_MCE | X86_CR4_LA57), %eax
+	movq	%rax, %cr4
+
+	/*
+	 * configure_5level_paging() updates the number of paging levels using
+	 * a trampoline in 32-bit addressable memory if the current number does
+	 * not match the desired number.
+	 *
+	 * Pass the boot_params pointer as the first argument. The second
+	 * argument is the relocated address of the page table to use instead
+	 * of the page table in trampoline memory (if required).
+	 */
+	movq	%r15, %rdi
+	leaq	rva(top_pgtable)(%rbx), %rsi
+	call	configure_5level_paging
+
+	/* Zero EFLAGS */
+	pushq	$0
+	popfq
+
+/*
+ * Copy the compressed kernel to the end of our buffer
+ * where decompression in place becomes safe.
+ */
+	leaq	(_bss-8)(%rip), %rsi
+	leaq	rva(_bss-8)(%rbx), %rdi
+	movl	$(_bss - startup_32), %ecx
+	shrl	$3, %ecx
+	std
+	rep	movsq
+	cld
+
+	/*
+	 * The GDT may get overwritten either during the copy we just did or
+	 * during extract_kernel below. To avoid any issues, repoint the GDTR
+	 * to the new copy of the GDT.
+	 */
+	leaq	rva(gdt64)(%rbx), %rax
+	leaq	rva(gdt)(%rbx), %rdx
+	movq	%rdx, 2(%rax)
+	lgdt	(%rax)
+
+/*
+ * Jump to the relocated address.
+ */
+	leaq	rva(.Lrelocated)(%rbx), %rax
+	jmp	*%rax
+SYM_CODE_END(startup_64)
+
+	.text
+SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated)
+
+/*
+ * Clear BSS (stack is currently empty)
+ */
+	xorl	%eax, %eax
+	leaq    _bss(%rip), %rdi
+	leaq    _ebss(%rip), %rcx
+	subq	%rdi, %rcx
+	shrq	$3, %rcx
+	rep	stosq
+
+	call	load_stage2_idt
+
+	/* Pass boot_params to initialize_identity_maps() */
+	movq	%r15, %rdi
+	call	initialize_identity_maps
+
+/*
+ * Do the extraction, and jump to the new kernel..
+ */
+	/* pass struct boot_params pointer and output target address */
+	movq	%r15, %rdi
+	movq	%rbp, %rsi
+	call	extract_kernel		/* returns kernel entry point in %rax */
+
+/*
+ * Jump to the decompressed kernel.
+ */
+	movq	%r15, %rsi
+	jmp	*%rax
+SYM_FUNC_END(.Lrelocated)
+
+	.code32
+SYM_FUNC_START_LOCAL_NOALIGN(.Lno_longmode)
+	/* This isn't an x86-64 CPU, so hang intentionally, we cannot continue */
+1:
+	hlt
+	jmp     1b
+SYM_FUNC_END(.Lno_longmode)
+
+	.globl	verify_cpu
+#include "../../kernel/verify_cpu.S"
+
+	.data
+SYM_DATA_START_LOCAL(gdt64)
+	.word	gdt_end - gdt - 1
+	.quad   gdt - gdt64
+SYM_DATA_END(gdt64)
+	.balign	8
+SYM_DATA_START_LOCAL(gdt)
+	.word	gdt_end - gdt - 1
+	.long	0
+	.word	0
+	.quad	0x00cf9a000000ffff	/* __KERNEL32_CS */
+	.quad	0x00af9a000000ffff	/* __KERNEL_CS */
+	.quad	0x00cf92000000ffff	/* __KERNEL_DS */
+	.quad	0x0080890000000000	/* TS descriptor */
+	.quad   0x0000000000000000	/* TS continued */
+SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end)
+
+SYM_DATA_START(boot_idt_desc)
+	.word	boot_idt_end - boot_idt - 1
+	.quad	0
+SYM_DATA_END(boot_idt_desc)
+	.balign 8
+SYM_DATA_START(boot_idt)
+	.rept	BOOT_IDT_ENTRIES
+	.quad	0
+	.quad	0
+	.endr
+SYM_DATA_END_LABEL(boot_idt, SYM_L_GLOBAL, boot_idt_end)
+
+/*
+ * Stack and heap for uncompression
+ */
+	.bss
+	.balign 4
+SYM_DATA_START_LOCAL(boot_stack)
+	.fill BOOT_STACK_SIZE, 1, 0
+	.balign 16
+SYM_DATA_END_LABEL(boot_stack, SYM_L_LOCAL, boot_stack_end)
+
+/*
+ * Space for page tables (not in .bss so not zeroed)
+ */
+	.section ".pgtable","aw",@nobits
+	.balign 4096
+SYM_DATA_LOCAL(pgtable,		.fill BOOT_PGT_SIZE, 1, 0)
+
+/*
+ * The page table is going to be used instead of page table in the trampoline
+ * memory.
+ */
+SYM_DATA_LOCAL(top_pgtable,	.fill PAGE_SIZE, 1, 0)

linux-7.2.3/arch/x86/boot/compressed/ident_map_64.c

@@ -0,0 +1,393 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This code is used on x86_64 to create page table identity mappings on
+ * demand by building up a new set of page tables (or appending to the
+ * existing ones), and then switching over to them when ready.
+ *
+ * Copyright (C) 2015-2016  Yinghai Lu
+ * Copyright (C)      2016  Kees Cook
+ */
+
+/* No MITIGATION_PAGE_TABLE_ISOLATION support needed either: */
+#undef CONFIG_MITIGATION_PAGE_TABLE_ISOLATION
+
+#include "error.h"
+#include "misc.h"
+
+/* These actually do the work of building the kernel identity maps. */
+#include <linux/pgtable.h>
+#include <asm/cmpxchg.h>
+#include <asm/trap_pf.h>
+#include <asm/trapnr.h>
+#include <asm/init.h>
+/* Use the static base for this part of the boot process */
+#undef __PAGE_OFFSET
+#define __PAGE_OFFSET __PAGE_OFFSET_BASE
+#include "../../mm/ident_map.c"
+
+#define _SETUP
+#include <asm/setup.h>	/* For COMMAND_LINE_SIZE */
+#undef _SETUP
+
+extern unsigned long get_cmd_line_ptr(void);
+
+/* Used by PAGE_KERN* macros: */
+pteval_t __default_kernel_pte_mask __read_mostly = ~0;
+
+/* Used to track our page table allocation area. */
+struct alloc_pgt_data {
+	unsigned char *pgt_buf;
+	unsigned long pgt_buf_size;
+	unsigned long pgt_buf_offset;
+};
+
+/*
+ * Allocates space for a page table entry, using struct alloc_pgt_data
+ * above. Besides the local callers, this is used as the allocation
+ * callback in mapping_info below.
+ */
+static void *alloc_pgt_page(void *context)
+{
+	struct alloc_pgt_data *pages = (struct alloc_pgt_data *)context;
+	unsigned char *entry;
+
+	/* Validate there is space available for a new page. */
+	if (pages->pgt_buf_offset >= pages->pgt_buf_size) {
+		debug_putstr("out of pgt_buf in " __FILE__ "!?\n");
+		debug_putaddr(pages->pgt_buf_offset);
+		debug_putaddr(pages->pgt_buf_size);
+		return NULL;
+	}
+
+	/* Consumed more tables than expected? */
+	if (pages->pgt_buf_offset == BOOT_PGT_SIZE_WARN) {
+		debug_putstr("pgt_buf running low in " __FILE__ "\n");
+		debug_putstr("Need to raise BOOT_PGT_SIZE?\n");
+		debug_putaddr(pages->pgt_buf_offset);
+		debug_putaddr(pages->pgt_buf_size);
+	}
+
+	entry = pages->pgt_buf + pages->pgt_buf_offset;
+	pages->pgt_buf_offset += PAGE_SIZE;
+
+	return entry;
+}
+
+/* Used to track our allocated page tables. */
+static struct alloc_pgt_data pgt_data;
+
+/* The top level page table entry pointer. */
+static unsigned long top_level_pgt;
+
+phys_addr_t physical_mask = (1ULL << __PHYSICAL_MASK_SHIFT) - 1;
+
+/*
+ * Mapping information structure passed to kernel_ident_mapping_init().
+ * Due to relocation, pointers must be assigned at run time not build time.
+ */
+static struct x86_mapping_info mapping_info;
+
+/*
+ * Adds the specified range to the identity mappings.
+ */
+void kernel_add_identity_map(unsigned long start, unsigned long end)
+{
+	int ret;
+
+	/* Align boundary to 2M. */
+	start = round_down(start, PMD_SIZE);
+	end = round_up(end, PMD_SIZE);
+	if (start >= end)
+		return;
+
+	/* Build the mapping. */
+	ret = kernel_ident_mapping_init(&mapping_info, (pgd_t *)top_level_pgt, start, end);
+	if (ret)
+		error("Error: kernel_ident_mapping_init() failed\n");
+}
+
+/* Locates and clears a region for a new top level page table. */
+void initialize_identity_maps(void *rmode)
+{
+	unsigned long cmdline;
+	struct setup_data *sd;
+
+	/* Exclude the encryption mask from __PHYSICAL_MASK */
+	physical_mask &= ~sme_me_mask;
+
+	/* Init mapping_info with run-time function/buffer pointers. */
+	mapping_info.alloc_pgt_page = alloc_pgt_page;
+	mapping_info.context = &pgt_data;
+	mapping_info.page_flag = __PAGE_KERNEL_LARGE_EXEC | sme_me_mask;
+	mapping_info.kernpg_flag = _KERNPG_TABLE;
+
+	/*
+	 * It should be impossible for this not to already be true,
+	 * but since calling this a second time would rewind the other
+	 * counters, let's just make sure this is reset too.
+	 */
+	pgt_data.pgt_buf_offset = 0;
+
+	/*
+	 * If we came here via startup_32(), cr3 will be _pgtable already
+	 * and we must append to the existing area instead of entirely
+	 * overwriting it.
+	 *
+	 * With 5-level paging, we use '_pgtable' to allocate the p4d page table,
+	 * the top-level page table is allocated separately.
+	 *
+	 * p4d_offset(top_level_pgt, 0) would cover both the 4- and 5-level
+	 * cases. On 4-level paging it's equal to 'top_level_pgt'.
+	 */
+	top_level_pgt = read_cr3_pa();
+	if (p4d_offset((pgd_t *)top_level_pgt, 0) == (p4d_t *)_pgtable) {
+		pgt_data.pgt_buf = _pgtable + BOOT_INIT_PGT_SIZE;
+		pgt_data.pgt_buf_size = BOOT_PGT_SIZE - BOOT_INIT_PGT_SIZE;
+		memset(pgt_data.pgt_buf, 0, pgt_data.pgt_buf_size);
+	} else {
+		pgt_data.pgt_buf = _pgtable;
+		pgt_data.pgt_buf_size = BOOT_PGT_SIZE;
+		memset(pgt_data.pgt_buf, 0, pgt_data.pgt_buf_size);
+		top_level_pgt = (unsigned long)alloc_pgt_page(&pgt_data);
+	}
+
+	/*
+	 * New page-table is set up - map the kernel image, boot_params and the
+	 * command line. The uncompressed kernel requires boot_params and the
+	 * command line to be mapped in the identity mapping. Map them
+	 * explicitly here in case the compressed kernel does not touch them,
+	 * or does not touch all the pages covering them.
+	 */
+	kernel_add_identity_map((unsigned long)_head, (unsigned long)_end);
+	boot_params_ptr = rmode;
+	kernel_add_identity_map((unsigned long)boot_params_ptr,
+				(unsigned long)(boot_params_ptr + 1));
+	cmdline = get_cmd_line_ptr();
+	kernel_add_identity_map(cmdline, cmdline + COMMAND_LINE_SIZE);
+
+	/*
+	 * Also map the setup_data entries passed via boot_params in case they
+	 * need to be accessed by uncompressed kernel via the identity mapping.
+	 */
+	sd = (struct setup_data *)boot_params_ptr->hdr.setup_data;
+	while (sd) {
+		unsigned long sd_addr = (unsigned long)sd;
+
+		kernel_add_identity_map(sd_addr, sd_addr + sizeof(*sd) + sd->len);
+		sd = (struct setup_data *)sd->next;
+	}
+
+	sev_prep_identity_maps(top_level_pgt);
+
+	/* Load the new page-table. */
+	write_cr3(top_level_pgt);
+
+	/*
+	 * Now that the required page table mappings are established and a
+	 * GHCB can be used, check for SNP guest/HV feature compatibility.
+	 */
+	snp_check_features();
+}
+
+static pte_t *split_large_pmd(struct x86_mapping_info *info,
+			      pmd_t *pmdp, unsigned long __address)
+{
+	unsigned long page_flags;
+	unsigned long address;
+	pte_t *pte;
+	pmd_t pmd;
+	int i;
+
+	pte = (pte_t *)info->alloc_pgt_page(info->context);
+	if (!pte)
+		return NULL;
+
+	address     = __address & PMD_MASK;
+	/* No large page - clear PSE flag */
+	page_flags  = info->page_flag & ~_PAGE_PSE;
+
+	/* Populate the PTEs */
+	for (i = 0; i < PTRS_PER_PMD; i++) {
+		set_pte(&pte[i], __pte(address | page_flags));
+		address += PAGE_SIZE;
+	}
+
+	/*
+	 * Ideally we need to clear the large PMD first and do a TLB
+	 * flush before we write the new PMD. But the 2M range of the
+	 * PMD might contain the code we execute and/or the stack
+	 * we are on, so we can't do that. But that should be safe here
+	 * because we are going from large to small mappings and we are
+	 * also the only user of the page-table, so there is no chance
+	 * of a TLB multihit.
+	 */
+	pmd = __pmd((unsigned long)pte | info->kernpg_flag);
+	set_pmd(pmdp, pmd);
+	/* Flush TLB to establish the new PMD */
+	write_cr3(top_level_pgt);
+
+	return pte + pte_index(__address);
+}
+
+static void clflush_page(unsigned long address)
+{
+	unsigned int flush_size;
+	char *cl, *start, *end;
+
+	/*
+	 * Hardcode cl-size to 64 - CPUID can't be used here because that might
+	 * cause another #VC exception and the GHCB is not ready to use yet.
+	 */
+	flush_size = 64;
+	start      = (char *)(address & PAGE_MASK);
+	end        = start + PAGE_SIZE;
+
+	/*
+	 * First make sure there are no pending writes on the cache-lines to
+	 * flush.
+	 */
+	asm volatile("mfence" : : : "memory");
+
+	for (cl = start; cl != end; cl += flush_size)
+		clflush(cl);
+}
+
+static int set_clr_page_flags(struct x86_mapping_info *info,
+			      unsigned long address,
+			      pteval_t set, pteval_t clr)
+{
+	pgd_t *pgdp = (pgd_t *)top_level_pgt;
+	p4d_t *p4dp;
+	pud_t *pudp;
+	pmd_t *pmdp;
+	pte_t *ptep, pte;
+
+	/*
+	 * First make sure there is a PMD mapping for 'address'.
+	 * It should already exist, but keep things generic.
+	 *
+	 * To map the page just read from it and fault it in if there is no
+	 * mapping yet. kernel_add_identity_map() can't be called here because
+	 * that would unconditionally map the address on PMD level, destroying
+	 * any PTE-level mappings that might already exist. Use assembly here
+	 * so the access won't be optimized away.
+	 */
+	asm volatile("mov %[address], %%r9"
+		     :: [address] "g" (*(unsigned long *)address)
+		     : "r9", "memory");
+
+	/*
+	 * The page is mapped at least with PMD size - so skip checks and walk
+	 * directly to the PMD.
+	 */
+	p4dp = p4d_offset(pgdp, address);
+	pudp = pud_offset(p4dp, address);
+	pmdp = pmd_offset(pudp, address);
+
+	if (pmd_leaf(*pmdp))
+		ptep = split_large_pmd(info, pmdp, address);
+	else
+		ptep = pte_offset_kernel(pmdp, address);
+
+	if (!ptep)
+		return -ENOMEM;
+
+	/*
+	 * Changing encryption attributes of a page requires to flush it from
+	 * the caches.
+	 */
+	if ((set | clr) & _PAGE_ENC) {
+		clflush_page(address);
+
+		/*
+		 * If the encryption attribute is being cleared, change the page state
+		 * to shared in the RMP table.
+		 */
+		if (clr)
+			snp_set_page_shared(__pa(address & PAGE_MASK));
+	}
+
+	/* Update PTE */
+	pte = *ptep;
+	pte = pte_set_flags(pte, set);
+	pte = pte_clear_flags(pte, clr);
+	set_pte(ptep, pte);
+
+	/*
+	 * If the encryption attribute is being set, then change the page state to
+	 * private in the RMP entry. The page state change must be done after the PTE
+	 * is updated.
+	 */
+	if (set & _PAGE_ENC)
+		snp_set_page_private(__pa(address & PAGE_MASK));
+
+	/* Flush TLB after changing encryption attribute */
+	write_cr3(top_level_pgt);
+
+	return 0;
+}
+
+int set_page_decrypted(unsigned long address)
+{
+	return set_clr_page_flags(&mapping_info, address, 0, _PAGE_ENC);
+}
+
+int set_page_encrypted(unsigned long address)
+{
+	return set_clr_page_flags(&mapping_info, address, _PAGE_ENC, 0);
+}
+
+int set_page_non_present(unsigned long address)
+{
+	return set_clr_page_flags(&mapping_info, address, 0, _PAGE_PRESENT);
+}
+
+static void do_pf_error(const char *msg, unsigned long error_code,
+			unsigned long address, unsigned long ip)
+{
+	error_putstr(msg);
+
+	error_putstr("\nError Code: ");
+	error_puthex(error_code);
+	error_putstr("\nCR2: 0x");
+	error_puthex(address);
+	error_putstr("\nRIP relative to _head: 0x");
+	error_puthex(ip - (unsigned long)_head);
+	error_putstr("\n");
+
+	error("Stopping.\n");
+}
+
+void do_boot_page_fault(struct pt_regs *regs, unsigned long error_code)
+{
+	unsigned long address = native_read_cr2();
+	unsigned long end;
+	bool ghcb_fault;
+
+	ghcb_fault = sev_es_check_ghcb_fault(address);
+
+	address   &= PMD_MASK;
+	end        = address + PMD_SIZE;
+
+	/*
+	 * Check for unexpected error codes. Unexpected are:
+	 *	- Faults on present pages
+	 *	- User faults
+	 *	- Reserved bits set
+	 */
+	if (error_code & (X86_PF_PROT | X86_PF_USER | X86_PF_RSVD))
+		do_pf_error("Unexpected page-fault:", error_code, address, regs->ip);
+	else if (ghcb_fault)
+		do_pf_error("Page-fault on GHCB page:", error_code, address, regs->ip);
+
+	/*
+	 * Error code is sane - now identity map the 2M region around
+	 * the faulting address.
+	 */
+	kernel_add_identity_map(address, end);
+}
+
+void do_boot_nmi_trap(struct pt_regs *regs, unsigned long error_code)
+{
+	spurious_nmi_count++;
+}

linux-7.2.3/arch/x86/boot/compressed/idt_64.c

@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <asm/trap_pf.h>
+#include <asm/segment.h>
+#include <asm/trapnr.h>
+#include "misc.h"
+
+static void set_idt_entry(int vector, void (*handler)(void))
+{
+	unsigned long address = (unsigned long)handler;
+	gate_desc entry;
+
+	memset(&entry, 0, sizeof(entry));
+
+	entry.offset_low    = (u16)(address & 0xffff);
+	entry.segment       = __KERNEL_CS;
+	entry.bits.type     = GATE_TRAP;
+	entry.bits.p        = 1;
+	entry.offset_middle = (u16)((address >> 16) & 0xffff);
+	entry.offset_high   = (u32)(address >> 32);
+
+	memcpy(&boot_idt[vector], &entry, sizeof(entry));
+}
+
+/* Have this here so we don't need to include <asm/desc.h> */
+static void load_boot_idt(const struct desc_ptr *dtr)
+{
+	asm volatile("lidt %0"::"m" (*dtr));
+}
+
+/* Setup IDT before kernel jumping to  .Lrelocated */
+void load_stage1_idt(void)
+{
+	boot_idt_desc.address = (unsigned long)boot_idt;
+
+
+	if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT))
+		set_idt_entry(X86_TRAP_VC, boot_stage1_vc);
+
+	load_boot_idt(&boot_idt_desc);
+}
+
+/*
+ * Setup IDT after kernel jumping to  .Lrelocated.
+ *
+ * initialize_identity_maps() needs a #PF handler to be setup
+ * in order to be able to fault-in identity mapping ranges; see
+ * do_boot_page_fault().
+ *
+ * This #PF handler setup needs to happen in load_stage2_idt() where the
+ * IDT is loaded and there the #VC IDT entry gets setup too.
+ *
+ * In order to be able to handle #VCs, one needs a GHCB which
+ * gets setup with an already set up pagetable, which is done in
+ * initialize_identity_maps(). And there's the catch 22: the boot #VC
+ * handler do_boot_stage2_vc() needs to call early_setup_ghcb() itself
+ * (and, especially set_page_decrypted()) because the SEV-ES setup code
+ * cannot initialize a GHCB as there's no #PF handler yet...
+ */
+void load_stage2_idt(void)
+{
+	boot_idt_desc.address = (unsigned long)boot_idt;
+
+	set_idt_entry(X86_TRAP_PF, boot_page_fault);
+	set_idt_entry(X86_TRAP_NMI, boot_nmi_trap);
+
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+	/*
+	 * Clear the second stage #VC handler in case guest types
+	 * needing #VC have not been detected.
+	 */
+	if (sev_status & BIT(1))
+		set_idt_entry(X86_TRAP_VC, boot_stage2_vc);
+	else
+		set_idt_entry(X86_TRAP_VC, NULL);
+#endif
+
+	load_boot_idt(&boot_idt_desc);
+}
+
+void cleanup_exception_handling(void)
+{
+	/*
+	 * Flush GHCB from cache and map it encrypted again when running as
+	 * SEV-ES guest.
+	 */
+	sev_es_shutdown_ghcb();
+
+	/* Set a null-idt, disabling #PF and #VC handling */
+	boot_idt_desc.size    = 0;
+	boot_idt_desc.address = 0;
+	load_boot_idt(&boot_idt_desc);
+}

linux-7.2.3/arch/x86/boot/compressed/idt_handlers_64.S

@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Early IDT handler entry points
+ *
+ * Copyright (C) 2019 SUSE
+ *
+ * Author: Joerg Roedel <jroedel@suse.de>
+ */
+
+#include <asm/segment.h>
+
+/* For ORIG_RAX */
+#include "../../entry/calling.h"
+
+.macro EXCEPTION_HANDLER name function error_code=0
+SYM_FUNC_START(\name)
+
+	/* Build pt_regs */
+	.if \error_code == 0
+	pushq   $0
+	.endif
+
+	pushq   %rdi
+	pushq   %rsi
+	pushq   %rdx
+	pushq   %rcx
+	pushq   %rax
+	pushq   %r8
+	pushq   %r9
+	pushq   %r10
+	pushq   %r11
+	pushq   %rbx
+	pushq   %rbp
+	pushq   %r12
+	pushq   %r13
+	pushq   %r14
+	pushq   %r15
+
+	/* Call handler with pt_regs */
+	movq    %rsp, %rdi
+	/* Error code is second parameter */
+	movq	ORIG_RAX(%rsp), %rsi
+	call    \function
+
+	/* Restore regs */
+	popq    %r15
+	popq    %r14
+	popq    %r13
+	popq    %r12
+	popq    %rbp
+	popq    %rbx
+	popq    %r11
+	popq    %r10
+	popq    %r9
+	popq    %r8
+	popq    %rax
+	popq    %rcx
+	popq    %rdx
+	popq    %rsi
+	popq    %rdi
+
+	/* Remove error code and return */
+	addq    $8, %rsp
+
+	iretq
+SYM_FUNC_END(\name)
+	.endm
+
+	.text
+	.code64
+
+EXCEPTION_HANDLER	boot_page_fault do_boot_page_fault error_code=1
+EXCEPTION_HANDLER	boot_nmi_trap do_boot_nmi_trap error_code=0
+
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+EXCEPTION_HANDLER	boot_stage1_vc do_vc_no_ghcb		error_code=1
+EXCEPTION_HANDLER	boot_stage2_vc do_boot_stage2_vc	error_code=1
+#endif

linux-7.2.3/arch/x86/boot/compressed/kaslr.c

@@ -0,0 +1,909 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * kaslr.c
+ *
+ * This contains the routines needed to generate a reasonable level of
+ * entropy to choose a randomized kernel base address offset in support
+ * of Kernel Address Space Layout Randomization (KASLR). Additionally
+ * handles walking the physical memory maps (and tracking memory regions
+ * to avoid) in order to select a physical memory location that can
+ * contain the entire properly aligned running kernel image.
+ *
+ */
+
+/*
+ * isspace() in linux/ctype.h is expected by next_args() to filter
+ * out "space/lf/tab". While boot/ctype.h conflicts with linux/ctype.h,
+ * since isdigit() is implemented in both of them. Hence disable it
+ * here.
+ */
+#define BOOT_CTYPE_H
+
+#include "misc.h"
+#include "error.h"
+#include "../string.h"
+#include "efi.h"
+
+#include <generated/compile.h>
+#include <generated/utsversion.h>
+#include <generated/utsrelease.h>
+
+#define _SETUP
+#include <asm/setup.h>	/* For COMMAND_LINE_SIZE */
+#undef _SETUP
+
+extern unsigned long get_cmd_line_ptr(void);
+
+/* Simplified build-specific string for starting entropy. */
+static const char build_str[] = UTS_RELEASE " (" LINUX_COMPILE_BY "@"
+		LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION;
+
+static unsigned long rotate_xor(unsigned long hash, const void *area,
+				size_t size)
+{
+	size_t i;
+	unsigned long *ptr = (unsigned long *)area;
+
+	for (i = 0; i < size / sizeof(hash); i++) {
+		/* Rotate by odd number of bits and XOR. */
+		hash = (hash << ((sizeof(hash) * 8) - 7)) | (hash >> 7);
+		hash ^= ptr[i];
+	}
+
+	return hash;
+}
+
+/* Attempt to create a simple but unpredictable starting entropy. */
+static unsigned long get_boot_seed(void)
+{
+	unsigned long hash = 0;
+
+	hash = rotate_xor(hash, build_str, sizeof(build_str));
+	hash = rotate_xor(hash, boot_params_ptr, sizeof(*boot_params_ptr));
+
+	return hash;
+}
+
+#define KASLR_COMPRESSED_BOOT
+#include "../../lib/kaslr.c"
+
+
+/* Only supporting at most 4 unusable memmap regions with kaslr */
+#define MAX_MEMMAP_REGIONS	4
+
+static bool memmap_too_large;
+
+
+/*
+ * Store memory limit: MAXMEM on 64-bit and KERNEL_IMAGE_SIZE on 32-bit.
+ * It may be reduced by "mem=nn[KMG]" or "memmap=nn[KMG]" command line options.
+ */
+static u64 mem_limit;
+
+/* Number of immovable memory regions */
+static int num_immovable_mem;
+
+enum mem_avoid_index {
+	MEM_AVOID_ZO_RANGE = 0,
+	MEM_AVOID_INITRD,
+	MEM_AVOID_CMDLINE,
+	MEM_AVOID_BOOTPARAMS,
+	MEM_AVOID_MEMMAP_BEGIN,
+	MEM_AVOID_MEMMAP_END = MEM_AVOID_MEMMAP_BEGIN + MAX_MEMMAP_REGIONS - 1,
+	MEM_AVOID_MAX,
+};
+
+static struct mem_vector mem_avoid[MEM_AVOID_MAX];
+
+static bool mem_overlaps(struct mem_vector *one, struct mem_vector *two)
+{
+	/* Item one is entirely before item two. */
+	if (one->start + one->size <= two->start)
+		return false;
+	/* Item one is entirely after item two. */
+	if (one->start >= two->start + two->size)
+		return false;
+	return true;
+}
+
+char *skip_spaces(const char *str)
+{
+	while (isspace(*str))
+		++str;
+	return (char *)str;
+}
+#include "../../../../lib/ctype.c"
+#include "../../../../lib/cmdline.c"
+
+static int
+parse_memmap(char *p, u64 *start, u64 *size)
+{
+	char *oldp;
+
+	if (!p)
+		return -EINVAL;
+
+	/* We don't care about this option here */
+	if (!strncmp(p, "exactmap", 8))
+		return -EINVAL;
+
+	oldp = p;
+	*size = memparse(p, &p);
+	if (p == oldp)
+		return -EINVAL;
+
+	switch (*p) {
+	case '#':
+	case '$':
+	case '!':
+		*start = memparse(p + 1, &p);
+		return 0;
+	case '@':
+		/*
+		 * memmap=nn@ss specifies usable region, should
+		 * be skipped
+		 */
+		*size = 0;
+		fallthrough;
+	default:
+		/*
+		 * If w/o offset, only size specified, memmap=nn[KMG] has the
+		 * same behaviour as mem=nn[KMG]. It limits the max address
+		 * system can use. Region above the limit should be avoided.
+		 */
+		*start = 0;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static void mem_avoid_memmap(char *str)
+{
+	static int i;
+
+	if (i >= MAX_MEMMAP_REGIONS)
+		return;
+
+	while (str && (i < MAX_MEMMAP_REGIONS)) {
+		int rc;
+		u64 start, size;
+		char *k = strchr(str, ',');
+
+		if (k)
+			*k++ = 0;
+
+		rc = parse_memmap(str, &start, &size);
+		if (rc < 0)
+			break;
+		str = k;
+
+		if (start == 0) {
+			/* Store the specified memory limit if size > 0 */
+			if (size > 0 && size < mem_limit)
+				mem_limit = size;
+
+			continue;
+		}
+
+		mem_avoid[MEM_AVOID_MEMMAP_BEGIN + i].start = start;
+		mem_avoid[MEM_AVOID_MEMMAP_BEGIN + i].size = size;
+		i++;
+	}
+
+	/* More than 4 memmaps, fail kaslr */
+	if ((i >= MAX_MEMMAP_REGIONS) && str)
+		memmap_too_large = true;
+}
+
+/* Store the number of 1GB huge pages which users specified: */
+static unsigned long max_gb_huge_pages;
+
+static void parse_gb_huge_pages(char *param, char *val)
+{
+	static bool gbpage_sz;
+	char *p;
+
+	if (!strcmp(param, "hugepagesz")) {
+		p = val;
+		if (memparse(p, &p) != PUD_SIZE) {
+			gbpage_sz = false;
+			return;
+		}
+
+		if (gbpage_sz)
+			warn("Repeatedly set hugeTLB page size of 1G!\n");
+		gbpage_sz = true;
+		return;
+	}
+
+	if (!strcmp(param, "hugepages") && gbpage_sz) {
+		p = val;
+		if (boot_kstrtoul(p, 0, &max_gb_huge_pages))
+			warn("Failed to parse hugepages= boot parameter\n");
+		return;
+	}
+}
+
+static void handle_mem_options(void)
+{
+	char *args = (char *)get_cmd_line_ptr();
+	size_t len;
+	char *tmp_cmdline;
+	char *param, *val;
+	u64 mem_size;
+
+	if (!args)
+		return;
+
+	len = strnlen(args, COMMAND_LINE_SIZE-1);
+	tmp_cmdline = malloc(len + 1);
+	if (!tmp_cmdline)
+		error("Failed to allocate space for tmp_cmdline");
+
+	memcpy(tmp_cmdline, args, len);
+	tmp_cmdline[len] = 0;
+	args = tmp_cmdline;
+
+	/* Chew leading spaces */
+	args = skip_spaces(args);
+
+	while (*args) {
+		args = next_arg(args, &param, &val);
+		/* Stop at -- */
+		if (!val && strcmp(param, "--") == 0)
+			break;
+
+		if (!strcmp(param, "memmap")) {
+			mem_avoid_memmap(val);
+		} else if (IS_ENABLED(CONFIG_X86_64) && strstr(param, "hugepages")) {
+			parse_gb_huge_pages(param, val);
+		} else if (!strcmp(param, "mem")) {
+			char *p = val;
+
+			if (!strcmp(p, "nopentium"))
+				continue;
+			mem_size = memparse(p, &p);
+			if (mem_size == 0)
+				break;
+
+			if (mem_size < mem_limit)
+				mem_limit = mem_size;
+		}
+	}
+
+	free(tmp_cmdline);
+	return;
+}
+
+/*
+ * In theory, KASLR can put the kernel anywhere in the range of [16M, MAXMEM)
+ * on 64-bit, and [16M, KERNEL_IMAGE_SIZE) on 32-bit.
+ *
+ * The mem_avoid array is used to store the ranges that need to be avoided
+ * when KASLR searches for an appropriate random address. We must avoid any
+ * regions that are unsafe to overlap with during decompression, and other
+ * things like the initrd, cmdline and boot_params. This comment seeks to
+ * explain mem_avoid as clearly as possible since incorrect mem_avoid
+ * memory ranges lead to really hard to debug boot failures.
+ *
+ * The initrd, cmdline, and boot_params are trivial to identify for
+ * avoiding. They are MEM_AVOID_INITRD, MEM_AVOID_CMDLINE, and
+ * MEM_AVOID_BOOTPARAMS respectively below.
+ *
+ * What is not obvious how to avoid is the range of memory that is used
+ * during decompression (MEM_AVOID_ZO_RANGE below). This range must cover
+ * the compressed kernel (ZO) and its run space, which is used to extract
+ * the uncompressed kernel (VO) and relocs.
+ *
+ * ZO's full run size sits against the end of the decompression buffer, so
+ * we can calculate where text, data, bss, etc of ZO are positioned more
+ * easily.
+ *
+ * For additional background, the decompression calculations can be found
+ * in header.S, and the memory diagram is based on the one found in misc.c.
+ *
+ * The following conditions are already enforced by the image layouts and
+ * associated code:
+ *  - input + input_size >= output + output_size
+ *  - kernel_total_size <= init_size
+ *  - kernel_total_size <= output_size (see Note below)
+ *  - output + init_size >= output + output_size
+ *
+ * (Note that kernel_total_size and output_size have no fundamental
+ * relationship, but output_size is passed to choose_random_location
+ * as a maximum of the two. The diagram is showing a case where
+ * kernel_total_size is larger than output_size, but this case is
+ * handled by bumping output_size.)
+ *
+ * The above conditions can be illustrated by a diagram:
+ *
+ * 0   output            input            input+input_size    output+init_size
+ * |     |                 |                             |             |
+ * |     |                 |                             |             |
+ * |-----|--------|--------|--------------|-----------|--|-------------|
+ *                |                       |           |
+ *                |                       |           |
+ * output+init_size-ZO_INIT_SIZE  output+output_size  output+kernel_total_size
+ *
+ * [output, output+init_size) is the entire memory range used for
+ * extracting the compressed image.
+ *
+ * [output, output+kernel_total_size) is the range needed for the
+ * uncompressed kernel (VO) and its run size (bss, brk, etc).
+ *
+ * [output, output+output_size) is VO plus relocs (i.e. the entire
+ * uncompressed payload contained by ZO). This is the area of the buffer
+ * written to during decompression.
+ *
+ * [output+init_size-ZO_INIT_SIZE, output+init_size) is the worst-case
+ * range of the copied ZO and decompression code. (i.e. the range
+ * covered backwards of size ZO_INIT_SIZE, starting from output+init_size.)
+ *
+ * [input, input+input_size) is the original copied compressed image (ZO)
+ * (i.e. it does not include its run size). This range must be avoided
+ * because it contains the data used for decompression.
+ *
+ * [input+input_size, output+init_size) is [_text, _end) for ZO. This
+ * range includes ZO's heap and stack, and must be avoided since it
+ * performs the decompression.
+ *
+ * Since the above two ranges need to be avoided and they are adjacent,
+ * they can be merged, resulting in: [input, output+init_size) which
+ * becomes the MEM_AVOID_ZO_RANGE below.
+ */
+static void mem_avoid_init(unsigned long input, unsigned long input_size,
+			   unsigned long output)
+{
+	unsigned long init_size = boot_params_ptr->hdr.init_size;
+	u64 initrd_start, initrd_size;
+	unsigned long cmd_line, cmd_line_size;
+
+	/*
+	 * Avoid the region that is unsafe to overlap during
+	 * decompression.
+	 */
+	mem_avoid[MEM_AVOID_ZO_RANGE].start = input;
+	mem_avoid[MEM_AVOID_ZO_RANGE].size = (output + init_size) - input;
+
+	/* Avoid initrd. */
+	initrd_start  = (u64)boot_params_ptr->ext_ramdisk_image << 32;
+	initrd_start |= boot_params_ptr->hdr.ramdisk_image;
+	initrd_size  = (u64)boot_params_ptr->ext_ramdisk_size << 32;
+	initrd_size |= boot_params_ptr->hdr.ramdisk_size;
+	mem_avoid[MEM_AVOID_INITRD].start = initrd_start;
+	mem_avoid[MEM_AVOID_INITRD].size = initrd_size;
+	/* No need to set mapping for initrd, it will be handled in VO. */
+
+	/* Avoid kernel command line. */
+	cmd_line = get_cmd_line_ptr();
+	/* Calculate size of cmd_line. */
+	if (cmd_line) {
+		cmd_line_size = strnlen((char *)cmd_line, COMMAND_LINE_SIZE-1) + 1;
+		mem_avoid[MEM_AVOID_CMDLINE].start = cmd_line;
+		mem_avoid[MEM_AVOID_CMDLINE].size = cmd_line_size;
+	}
+
+	/* Avoid boot parameters. */
+	mem_avoid[MEM_AVOID_BOOTPARAMS].start = (unsigned long)boot_params_ptr;
+	mem_avoid[MEM_AVOID_BOOTPARAMS].size = sizeof(*boot_params_ptr);
+
+	/* We don't need to set a mapping for setup_data. */
+
+	/* Mark the memmap regions we need to avoid */
+	handle_mem_options();
+
+	/* Enumerate the immovable memory regions */
+	num_immovable_mem = count_immovable_mem_regions();
+}
+
+/*
+ * Does this memory vector overlap a known avoided area? If so, record the
+ * overlap region with the lowest address.
+ */
+static bool mem_avoid_overlap(struct mem_vector *img,
+			      struct mem_vector *overlap)
+{
+	int i;
+	struct setup_data *ptr;
+	u64 earliest = img->start + img->size;
+	bool is_overlapping = false;
+
+	for (i = 0; i < MEM_AVOID_MAX; i++) {
+		if (mem_overlaps(img, &mem_avoid[i]) &&
+		    mem_avoid[i].start < earliest) {
+			*overlap = mem_avoid[i];
+			earliest = overlap->start;
+			is_overlapping = true;
+		}
+	}
+
+	/* Avoid all entries in the setup_data linked list. */
+	ptr = (struct setup_data *)(unsigned long)boot_params_ptr->hdr.setup_data;
+	while (ptr) {
+		struct mem_vector avoid;
+
+		avoid.start = (unsigned long)ptr;
+		avoid.size = sizeof(*ptr) + ptr->len;
+
+		if (mem_overlaps(img, &avoid) && (avoid.start < earliest)) {
+			*overlap = avoid;
+			earliest = overlap->start;
+			is_overlapping = true;
+		}
+
+		if (ptr->type == SETUP_INDIRECT &&
+		    ((struct setup_indirect *)ptr->data)->type != SETUP_INDIRECT) {
+			avoid.start = ((struct setup_indirect *)ptr->data)->addr;
+			avoid.size = ((struct setup_indirect *)ptr->data)->len;
+
+			if (mem_overlaps(img, &avoid) && (avoid.start < earliest)) {
+				*overlap = avoid;
+				earliest = overlap->start;
+				is_overlapping = true;
+			}
+		}
+
+		ptr = (struct setup_data *)(unsigned long)ptr->next;
+	}
+
+	return is_overlapping;
+}
+
+struct slot_area {
+	u64 addr;
+	unsigned long num;
+};
+
+#define MAX_SLOT_AREA 100
+
+static struct slot_area slot_areas[MAX_SLOT_AREA];
+static unsigned int slot_area_index;
+static unsigned long slot_max;
+
+static void store_slot_info(struct mem_vector *region, unsigned long image_size)
+{
+	struct slot_area slot_area;
+
+	if (slot_area_index == MAX_SLOT_AREA)
+		return;
+
+	slot_area.addr = region->start;
+	slot_area.num = 1 + (region->size - image_size) / CONFIG_PHYSICAL_ALIGN;
+
+	slot_areas[slot_area_index++] = slot_area;
+	slot_max += slot_area.num;
+}
+
+/*
+ * Skip as many 1GB huge pages as possible in the passed region
+ * according to the number which users specified:
+ */
+static void
+process_gb_huge_pages(struct mem_vector *region, unsigned long image_size)
+{
+	u64 pud_start, pud_end;
+	unsigned long gb_huge_pages;
+	struct mem_vector tmp;
+
+	if (!IS_ENABLED(CONFIG_X86_64) || !max_gb_huge_pages) {
+		store_slot_info(region, image_size);
+		return;
+	}
+
+	/* Are there any 1GB pages in the region? */
+	pud_start = ALIGN(region->start, PUD_SIZE);
+	pud_end = ALIGN_DOWN(region->start + region->size, PUD_SIZE);
+
+	/* No good 1GB huge pages found: */
+	if (pud_start >= pud_end) {
+		store_slot_info(region, image_size);
+		return;
+	}
+
+	/* Check if the head part of the region is usable. */
+	if (pud_start >= region->start + image_size) {
+		tmp.start = region->start;
+		tmp.size = pud_start - region->start;
+		store_slot_info(&tmp, image_size);
+	}
+
+	/* Skip the good 1GB pages. */
+	gb_huge_pages = (pud_end - pud_start) >> PUD_SHIFT;
+	if (gb_huge_pages > max_gb_huge_pages) {
+		pud_end = pud_start + (max_gb_huge_pages << PUD_SHIFT);
+		max_gb_huge_pages = 0;
+	} else {
+		max_gb_huge_pages -= gb_huge_pages;
+	}
+
+	/* Check if the tail part of the region is usable. */
+	if (region->start + region->size >= pud_end + image_size) {
+		tmp.start = pud_end;
+		tmp.size = region->start + region->size - pud_end;
+		store_slot_info(&tmp, image_size);
+	}
+}
+
+static u64 slots_fetch_random(void)
+{
+	unsigned long slot;
+	unsigned int i;
+
+	/* Handle case of no slots stored. */
+	if (slot_max == 0)
+		return 0;
+
+	slot = kaslr_get_random_long("Physical") % slot_max;
+
+	for (i = 0; i < slot_area_index; i++) {
+		if (slot >= slot_areas[i].num) {
+			slot -= slot_areas[i].num;
+			continue;
+		}
+		return slot_areas[i].addr + ((u64)slot * CONFIG_PHYSICAL_ALIGN);
+	}
+
+	if (i == slot_area_index)
+		debug_putstr("slots_fetch_random() failed!?\n");
+	return 0;
+}
+
+static void __process_mem_region(struct mem_vector *entry,
+				 unsigned long minimum,
+				 unsigned long image_size)
+{
+	struct mem_vector region, overlap;
+	u64 region_end;
+
+	/* Enforce minimum and memory limit. */
+	region.start = max_t(u64, entry->start, minimum);
+	region_end = min(entry->start + entry->size, mem_limit);
+
+	/* Give up if slot area array is full. */
+	while (slot_area_index < MAX_SLOT_AREA) {
+		/* Potentially raise address to meet alignment needs. */
+		region.start = ALIGN(region.start, CONFIG_PHYSICAL_ALIGN);
+
+		/* Did we raise the address above the passed in memory entry? */
+		if (region.start > region_end)
+			return;
+
+		/* Reduce size by any delta from the original address. */
+		region.size = region_end - region.start;
+
+		/* Return if region can't contain decompressed kernel */
+		if (region.size < image_size)
+			return;
+
+		/* If nothing overlaps, store the region and return. */
+		if (!mem_avoid_overlap(&region, &overlap)) {
+			process_gb_huge_pages(&region, image_size);
+			return;
+		}
+
+		/* Store beginning of region if holds at least image_size. */
+		if (overlap.start >= region.start + image_size) {
+			region.size = overlap.start - region.start;
+			process_gb_huge_pages(&region, image_size);
+		}
+
+		/* Clip off the overlapping region and start over. */
+		region.start = overlap.start + overlap.size;
+	}
+}
+
+static bool process_mem_region(struct mem_vector *region,
+			       unsigned long minimum,
+			       unsigned long image_size)
+{
+	int i;
+	/*
+	 * If no immovable memory found, or MEMORY_HOTREMOVE disabled,
+	 * use @region directly.
+	 */
+	if (!num_immovable_mem) {
+		__process_mem_region(region, minimum, image_size);
+
+		if (slot_area_index == MAX_SLOT_AREA) {
+			debug_putstr("Aborted e820/efi memmap scan (slot_areas full)!\n");
+			return true;
+		}
+		return false;
+	}
+
+#if defined(CONFIG_MEMORY_HOTREMOVE) && defined(CONFIG_ACPI)
+	/*
+	 * If immovable memory found, filter the intersection between
+	 * immovable memory and @region.
+	 */
+	for (i = 0; i < num_immovable_mem; i++) {
+		u64 start, end, entry_end, region_end;
+		struct mem_vector entry;
+
+		if (!mem_overlaps(region, &immovable_mem[i]))
+			continue;
+
+		start = immovable_mem[i].start;
+		end = start + immovable_mem[i].size;
+		region_end = region->start + region->size;
+
+		entry.start = clamp(region->start, start, end);
+		entry_end = clamp(region_end, start, end);
+		entry.size = entry_end - entry.start;
+
+		__process_mem_region(&entry, minimum, image_size);
+
+		if (slot_area_index == MAX_SLOT_AREA) {
+			debug_putstr("Aborted e820/efi memmap scan when walking immovable regions(slot_areas full)!\n");
+			return true;
+		}
+	}
+#endif
+	return false;
+}
+
+#ifdef CONFIG_EFI
+
+/*
+ * Only EFI_CONVENTIONAL_MEMORY and EFI_UNACCEPTED_MEMORY (if supported) are
+ * guaranteed to be free.
+ *
+ * Pick free memory more conservatively than the EFI spec allows: according to
+ * the spec, EFI_BOOT_SERVICES_{CODE|DATA} are also free memory and thus
+ * available to place the kernel image into, but in practice there's firmware
+ * where using that memory leads to crashes. Buggy vendor EFI code registers
+ * for an event that triggers on SetVirtualAddressMap(). The handler assumes
+ * that EFI_BOOT_SERVICES_DATA memory has not been touched by loader yet, which
+ * is probably true for Windows.
+ *
+ * Preserve EFI_BOOT_SERVICES_* regions until after SetVirtualAddressMap().
+ */
+static inline bool memory_type_is_free(efi_memory_desc_t *md)
+{
+	if (md->type == EFI_CONVENTIONAL_MEMORY)
+		return true;
+
+	if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) &&
+	    md->type == EFI_UNACCEPTED_MEMORY)
+		    return true;
+
+	return false;
+}
+
+/*
+ * Returns true if we processed the EFI memmap, which we prefer over the E820
+ * table if it is available.
+ */
+static bool
+process_efi_entries(unsigned long minimum, unsigned long image_size)
+{
+	struct efi_info *e = &boot_params_ptr->efi_info;
+	bool efi_mirror_found = false;
+	struct mem_vector region;
+	efi_memory_desc_t *md;
+	unsigned long pmap;
+	char *signature;
+	u32 nr_desc;
+	int i;
+
+	signature = (char *)&e->efi_loader_signature;
+	if (strncmp(signature, EFI32_LOADER_SIGNATURE, 4) &&
+	    strncmp(signature, EFI64_LOADER_SIGNATURE, 4))
+		return false;
+
+#ifdef CONFIG_X86_32
+	/* Can't handle data above 4GB at this time */
+	if (e->efi_memmap_hi) {
+		warn("EFI memmap is above 4GB, can't be handled now on x86_32. EFI should be disabled.\n");
+		return false;
+	}
+	pmap =  e->efi_memmap;
+#else
+	pmap = (e->efi_memmap | ((__u64)e->efi_memmap_hi << 32));
+#endif
+
+	nr_desc = e->efi_memmap_size / e->efi_memdesc_size;
+	for (i = 0; i < nr_desc; i++) {
+		md = efi_early_memdesc_ptr(pmap, e->efi_memdesc_size, i);
+		if (md->attribute & EFI_MEMORY_MORE_RELIABLE) {
+			efi_mirror_found = true;
+			break;
+		}
+	}
+
+	for (i = 0; i < nr_desc; i++) {
+		md = efi_early_memdesc_ptr(pmap, e->efi_memdesc_size, i);
+
+		if (!memory_type_is_free(md))
+			continue;
+
+		if (efi_soft_reserve_enabled() &&
+		    (md->attribute & EFI_MEMORY_SP))
+			continue;
+
+		if (efi_mirror_found &&
+		    !(md->attribute & EFI_MEMORY_MORE_RELIABLE))
+			continue;
+
+		region.start = md->phys_addr;
+		region.size = md->num_pages << EFI_PAGE_SHIFT;
+		if (process_mem_region(&region, minimum, image_size))
+			break;
+	}
+	return true;
+}
+#else
+static inline bool
+process_efi_entries(unsigned long minimum, unsigned long image_size)
+{
+	return false;
+}
+#endif
+
+static void process_e820_entries(unsigned long minimum,
+				 unsigned long image_size)
+{
+	int i;
+	struct mem_vector region;
+	struct boot_e820_entry *entry;
+
+	/* Verify potential e820 positions, appending to slots list. */
+	for (i = 0; i < boot_params_ptr->e820_entries; i++) {
+		entry = &boot_params_ptr->e820_table[i];
+		/* Skip non-RAM entries. */
+		if (entry->type != E820_TYPE_RAM)
+			continue;
+		region.start = entry->addr;
+		region.size = entry->size;
+		if (process_mem_region(&region, minimum, image_size))
+			break;
+	}
+}
+
+/*
+ * If KHO is active, only process its scratch areas to ensure we are not
+ * stepping onto preserved memory.
+ */
+static bool process_kho_entries(unsigned long minimum, unsigned long image_size)
+{
+	struct kho_scratch *kho_scratch;
+	struct setup_data *ptr;
+	struct kho_data *kho;
+	int i, nr_areas = 0;
+
+	if (!IS_ENABLED(CONFIG_KEXEC_HANDOVER))
+		return false;
+
+	ptr = (struct setup_data *)(unsigned long)boot_params_ptr->hdr.setup_data;
+	while (ptr) {
+		if (ptr->type == SETUP_KEXEC_KHO) {
+			kho = (struct kho_data *)(unsigned long)ptr->data;
+			kho_scratch = (void *)(unsigned long)kho->scratch_addr;
+			nr_areas = kho->scratch_size / sizeof(*kho_scratch);
+			break;
+		}
+
+		ptr = (struct setup_data *)(unsigned long)ptr->next;
+	}
+
+	if (!nr_areas)
+		return false;
+
+	for (i = 0; i < nr_areas; i++) {
+		struct kho_scratch *area = &kho_scratch[i];
+		struct mem_vector region = {
+			.start = area->addr,
+			.size = area->size,
+		};
+
+		if (process_mem_region(&region, minimum, image_size))
+			break;
+	}
+
+	return true;
+}
+
+static unsigned long find_random_phys_addr(unsigned long minimum,
+					   unsigned long image_size)
+{
+	u64 phys_addr;
+
+	/* Bail out early if it's impossible to succeed. */
+	if (minimum + image_size > mem_limit)
+		return 0;
+
+	/* Check if we had too many memmaps. */
+	if (memmap_too_large) {
+		debug_putstr("Aborted memory entries scan (more than 4 memmap= args)!\n");
+		return 0;
+	}
+
+	/*
+	 * During kexec handover only process KHO scratch areas that are known
+	 * not to contain any data that must be preserved.
+	 */
+	if (!process_kho_entries(minimum, image_size) &&
+	    !process_efi_entries(minimum, image_size))
+		process_e820_entries(minimum, image_size);
+
+	phys_addr = slots_fetch_random();
+
+	/* Perform a final check to make sure the address is in range. */
+	if (phys_addr < minimum || phys_addr + image_size > mem_limit) {
+		warn("Invalid physical address chosen!\n");
+		return 0;
+	}
+
+	return (unsigned long)phys_addr;
+}
+
+static unsigned long find_random_virt_addr(unsigned long minimum,
+					   unsigned long image_size)
+{
+	unsigned long slots, random_addr;
+
+	/*
+	 * There are how many CONFIG_PHYSICAL_ALIGN-sized slots
+	 * that can hold image_size within the range of minimum to
+	 * KERNEL_IMAGE_SIZE?
+	 */
+	slots = 1 + (KERNEL_IMAGE_SIZE - minimum - image_size) / CONFIG_PHYSICAL_ALIGN;
+
+	random_addr = kaslr_get_random_long("Virtual") % slots;
+
+	return random_addr * CONFIG_PHYSICAL_ALIGN + minimum;
+}
+
+/*
+ * Since this function examines addresses much more numerically,
+ * it takes the input and output pointers as 'unsigned long'.
+ */
+void choose_random_location(unsigned long input,
+			    unsigned long input_size,
+			    unsigned long *output,
+			    unsigned long output_size,
+			    unsigned long *virt_addr)
+{
+	unsigned long random_addr, min_addr;
+
+	if (cmdline_find_option_bool("nokaslr")) {
+		warn("KASLR disabled: 'nokaslr' on cmdline.");
+		return;
+	}
+
+	boot_params_ptr->hdr.loadflags |= KASLR_FLAG;
+
+	if (IS_ENABLED(CONFIG_X86_32))
+		mem_limit = KERNEL_IMAGE_SIZE;
+	else
+		mem_limit = MAXMEM;
+
+	/* Record the various known unsafe memory ranges. */
+	mem_avoid_init(input, input_size, *output);
+
+	/*
+	 * Low end of the randomization range should be the
+	 * smaller of 512M or the initial kernel image
+	 * location:
+	 */
+	min_addr = min(*output, 512UL << 20);
+	/* Make sure minimum is aligned. */
+	min_addr = ALIGN(min_addr, CONFIG_PHYSICAL_ALIGN);
+
+	/* Walk available memory entries to find a random address. */
+	random_addr = find_random_phys_addr(min_addr, output_size);
+	if (!random_addr) {
+		warn("Physical KASLR disabled: no suitable memory region!");
+	} else {
+		/* Update the new physical address location. */
+		if (*output != random_addr)
+			*output = random_addr;
+	}
+
+
+	/* Pick random virtual address starting from LOAD_PHYSICAL_ADDR. */
+	if (IS_ENABLED(CONFIG_X86_64))
+		random_addr = find_random_virt_addr(LOAD_PHYSICAL_ADDR, output_size);
+	*virt_addr = random_addr;
+}

linux-7.2.3/arch/x86/boot/compressed/kernel_info.S

@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <asm/bootparam.h>
+
+	.section ".rodata.kernel_info", "a"
+
+	.global kernel_info
+
+kernel_info:
+	/* Header, Linux top (structure). */
+	.ascii	"LToP"
+	/* Size. */
+	.long	kernel_info_var_len_data - kernel_info
+	/* Size total. */
+	.long	kernel_info_end - kernel_info
+
+	/* Maximal allowed type for setup_data and setup_indirect structs. */
+	.long	SETUP_TYPE_MAX
+
+kernel_info_var_len_data:
+	/* Empty for time being... */
+kernel_info_end:

linux-7.2.3/arch/x86/boot/compressed/mem.c

@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "error.h"
+#include "misc.h"
+#include "tdx.h"
+#include "sev.h"
+#include <asm/shared/tdx.h>
+
+/*
+ * accept_memory() and process_unaccepted_memory() called from EFI stub which
+ * runs before decompressor and its early_tdx_detect().
+ *
+ * Enumerate TDX directly from the early users.
+ */
+static bool early_is_tdx_guest(void)
+{
+	static bool once;
+	static bool is_tdx;
+
+	if (!IS_ENABLED(CONFIG_INTEL_TDX_GUEST))
+		return false;
+
+	if (!once) {
+		u32 eax, sig[3];
+
+		cpuid_count(TDX_CPUID_LEAF_ID, 0, &eax,
+			    &sig[0], &sig[2],  &sig[1]);
+		is_tdx = !memcmp(TDX_IDENT, sig, sizeof(sig));
+		once = true;
+	}
+
+	return is_tdx;
+}
+
+void arch_accept_memory(phys_addr_t start, phys_addr_t end)
+{
+	/* Platform-specific memory-acceptance call goes here */
+	if (early_is_tdx_guest()) {
+		if (!tdx_accept_memory(start, end))
+			panic("TDX: Failed to accept memory\n");
+	} else if (early_is_sevsnp_guest()) {
+		snp_accept_memory(start, end);
+	} else {
+		error("Cannot accept memory: unknown platform\n");
+	}
+}
+
+bool init_unaccepted_memory(void)
+{
+	guid_t guid = LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID;
+	struct efi_unaccepted_memory *table;
+	unsigned long cfg_table_pa;
+	unsigned int cfg_table_len;
+	enum efi_type et;
+	int ret;
+
+	et = efi_get_type(boot_params_ptr);
+	if (et == EFI_TYPE_NONE)
+		return false;
+
+	ret = efi_get_conf_table(boot_params_ptr, &cfg_table_pa, &cfg_table_len);
+	if (ret) {
+		warn("EFI config table not found.");
+		return false;
+	}
+
+	table = (void *)efi_find_vendor_table(boot_params_ptr, cfg_table_pa,
+					      cfg_table_len, guid);
+	if (!table)
+		return false;
+
+	if (table->version != 1)
+		error("Unknown version of unaccepted memory table\n");
+
+	/*
+	 * In many cases unaccepted_table is already set by EFI stub, but it
+	 * has to be initialized again to cover cases when the table is not
+	 * allocated by EFI stub or EFI stub copied the kernel image with
+	 * efi_relocate_kernel() before the variable is set.
+	 *
+	 * It must be initialized before the first usage of accept_memory().
+	 */
+	unaccepted_table = table;
+
+	return true;
+}

linux-7.2.3/arch/x86/boot/compressed/mem_encrypt.S

@@ -0,0 +1,324 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * AMD Memory Encryption Support
+ *
+ * Copyright (C) 2017 Advanced Micro Devices, Inc.
+ *
+ * Author: Tom Lendacky <thomas.lendacky@amd.com>
+ */
+
+#include <linux/linkage.h>
+
+#include <asm/processor-flags.h>
+#include <asm/msr.h>
+#include <asm/asm-offsets.h>
+#include <asm/segment.h>
+#include <asm/trapnr.h>
+
+	.text
+	.code32
+SYM_FUNC_START(get_sev_encryption_bit)
+	push	%ebx
+
+	movl	$0x80000000, %eax	/* CPUID to check the highest leaf */
+	cpuid
+	cmpl	$0x8000001f, %eax	/* See if 0x8000001f is available */
+	jb	.Lno_sev
+
+	/*
+	 * Check for the SEV feature:
+	 *   CPUID Fn8000_001F[EAX] - Bit 1
+	 *   CPUID Fn8000_001F[EBX] - Bits 5:0
+	 *     Pagetable bit position used to indicate encryption
+	 */
+	movl	$0x8000001f, %eax
+	cpuid
+	bt	$1, %eax		/* Check if SEV is available */
+	jnc	.Lno_sev
+
+	movl	$MSR_AMD64_SEV, %ecx	/* Read the SEV MSR */
+	rdmsr
+	bt	$MSR_AMD64_SEV_ENABLED_BIT, %eax	/* Check if SEV is active */
+	jnc	.Lno_sev
+
+	movl	%ebx, %eax
+	andl	$0x3f, %eax		/* Return the encryption bit location */
+	jmp	.Lsev_exit
+
+.Lno_sev:
+	xor	%eax, %eax
+
+.Lsev_exit:
+	pop	%ebx
+	RET
+SYM_FUNC_END(get_sev_encryption_bit)
+
+/**
+ * sev_es_req_cpuid - Request a CPUID value from the Hypervisor using
+ *		      the GHCB MSR protocol
+ *
+ * @%eax:	Register to request (0=EAX, 1=EBX, 2=ECX, 3=EDX)
+ * @%edx:	CPUID Function
+ *
+ * Returns 0 in %eax on success, non-zero on failure
+ * %edx returns CPUID value on success
+ */
+SYM_CODE_START_LOCAL(sev_es_req_cpuid)
+	shll	$30, %eax
+	orl     $0x00000004, %eax
+	movl    $MSR_AMD64_SEV_ES_GHCB, %ecx
+	wrmsr
+	rep; vmmcall		# VMGEXIT
+	rdmsr
+
+	/* Check response */
+	movl	%eax, %ecx
+	andl	$0x3ffff000, %ecx	# Bits [12-29] MBZ
+	jnz	2f
+
+	/* Check return code */
+	andl    $0xfff, %eax
+	cmpl    $5, %eax
+	jne	2f
+
+	/* All good - return success */
+	xorl	%eax, %eax
+1:
+	RET
+2:
+	movl	$-1, %eax
+	jmp	1b
+SYM_CODE_END(sev_es_req_cpuid)
+
+SYM_CODE_START_LOCAL(startup32_vc_handler)
+	pushl	%eax
+	pushl	%ebx
+	pushl	%ecx
+	pushl	%edx
+
+	/* Keep CPUID function in %ebx */
+	movl	%eax, %ebx
+
+	/* Check if error-code == SVM_EXIT_CPUID */
+	cmpl	$0x72, 16(%esp)
+	jne	.Lfail
+
+	movl	$0, %eax		# Request CPUID[fn].EAX
+	movl	%ebx, %edx		# CPUID fn
+	call	sev_es_req_cpuid	# Call helper
+	testl	%eax, %eax		# Check return code
+	jnz	.Lfail
+	movl	%edx, 12(%esp)		# Store result
+
+	movl	$1, %eax		# Request CPUID[fn].EBX
+	movl	%ebx, %edx		# CPUID fn
+	call	sev_es_req_cpuid	# Call helper
+	testl	%eax, %eax		# Check return code
+	jnz	.Lfail
+	movl	%edx, 8(%esp)		# Store result
+
+	movl	$2, %eax		# Request CPUID[fn].ECX
+	movl	%ebx, %edx		# CPUID fn
+	call	sev_es_req_cpuid	# Call helper
+	testl	%eax, %eax		# Check return code
+	jnz	.Lfail
+	movl	%edx, 4(%esp)		# Store result
+
+	movl	$3, %eax		# Request CPUID[fn].EDX
+	movl	%ebx, %edx		# CPUID fn
+	call	sev_es_req_cpuid	# Call helper
+	testl	%eax, %eax		# Check return code
+	jnz	.Lfail
+	movl	%edx, 0(%esp)		# Store result
+
+	/*
+	 * Sanity check CPUID results from the Hypervisor. See comment in
+	 * do_vc_no_ghcb() for more details on why this is necessary.
+	 */
+
+	/* Fail if SEV leaf not available in CPUID[0x80000000].EAX */
+	cmpl    $0x80000000, %ebx
+	jne     .Lcheck_sev
+	cmpl    $0x8000001f, 12(%esp)
+	jb      .Lfail
+	jmp     .Ldone
+
+.Lcheck_sev:
+	/* Fail if SEV bit not set in CPUID[0x8000001f].EAX[1] */
+	cmpl    $0x8000001f, %ebx
+	jne     .Ldone
+	btl     $1, 12(%esp)
+	jnc     .Lfail
+
+.Ldone:
+	popl	%edx
+	popl	%ecx
+	popl	%ebx
+	popl	%eax
+
+	/* Remove error code */
+	addl	$4, %esp
+
+	/* Jump over CPUID instruction */
+	addl	$2, (%esp)
+
+	iret
+.Lfail:
+	/* Send terminate request to Hypervisor */
+	movl    $0x100, %eax
+	xorl    %edx, %edx
+	movl    $MSR_AMD64_SEV_ES_GHCB, %ecx
+	wrmsr
+	rep; vmmcall
+
+	/* If request fails, go to hlt loop */
+	hlt
+	jmp .Lfail
+SYM_CODE_END(startup32_vc_handler)
+
+/*
+ * Write an IDT entry into boot32_idt
+ *
+ * Parameters:
+ *
+ * %eax:	Handler address
+ * %edx:	Vector number
+ * %ecx:	IDT address
+ */
+SYM_FUNC_START_LOCAL(startup32_set_idt_entry)
+	/* IDT entry address to %ecx */
+	leal	(%ecx, %edx, 8), %ecx
+
+	/* Build IDT entry, lower 4 bytes */
+	movl    %eax, %edx
+	andl    $0x0000ffff, %edx		# Target code segment offset [15:0]
+	orl	$(__KERNEL32_CS << 16), %edx	# Target code segment selector
+
+	/* Store lower 4 bytes to IDT */
+	movl    %edx, (%ecx)
+
+	/* Build IDT entry, upper 4 bytes */
+	movl    %eax, %edx
+	andl    $0xffff0000, %edx	# Target code segment offset [31:16]
+	orl     $0x00008e00, %edx	# Present, Type 32-bit Interrupt Gate
+
+	/* Store upper 4 bytes to IDT */
+	movl    %edx, 4(%ecx)
+
+	RET
+SYM_FUNC_END(startup32_set_idt_entry)
+
+SYM_FUNC_START(startup32_load_idt)
+	push	%ebp
+	push	%ebx
+
+	call	1f
+1:	pop	%ebp
+
+	leal    (boot32_idt - 1b)(%ebp), %ebx
+
+	/* #VC handler */
+	leal    (startup32_vc_handler - 1b)(%ebp), %eax
+	movl    $X86_TRAP_VC, %edx
+	movl	%ebx, %ecx
+	call    startup32_set_idt_entry
+
+	/* Load IDT */
+	leal	(boot32_idt_desc - 1b)(%ebp), %ecx
+	movl	%ebx, 2(%ecx)
+	lidt    (%ecx)
+
+	pop	%ebx
+	pop	%ebp
+	RET
+SYM_FUNC_END(startup32_load_idt)
+
+/*
+ * Check for the correct C-bit position when the startup_32 boot-path is used.
+ *
+ * The check makes use of the fact that all memory is encrypted when paging is
+ * disabled. The function creates 64 bits of random data using the RDRAND
+ * instruction. RDRAND is mandatory for SEV guests, so always available. If the
+ * hypervisor violates that the kernel will crash right here.
+ *
+ * The 64 bits of random data are stored to a memory location and at the same
+ * time kept in the %eax and %ebx registers. Since encryption is always active
+ * when paging is off the random data will be stored encrypted in main memory.
+ *
+ * Then paging is enabled. When the C-bit position is correct all memory is
+ * still mapped encrypted and comparing the register values with memory will
+ * succeed. An incorrect C-bit position will map all memory unencrypted, so that
+ * the compare will use the encrypted random data and fail.
+ */
+SYM_FUNC_START(startup32_check_sev_cbit)
+	pushl	%ebx
+	pushl	%ebp
+
+	call	0f
+0:	popl	%ebp
+
+	/* Check for non-zero sev_status */
+	movl	(sev_status - 0b)(%ebp), %eax
+	testl	%eax, %eax
+	jz	4f
+
+	/*
+	 * Get two 32-bit random values - Don't bail out if RDRAND fails
+	 * because it is better to prevent forward progress if no random value
+	 * can be gathered.
+	 */
+1:	rdrand	%eax
+	jnc	1b
+2:	rdrand	%ebx
+	jnc	2b
+
+	/* Store to memory and keep it in the registers */
+	leal	(sev_check_data - 0b)(%ebp), %ebp
+	movl	%eax, 0(%ebp)
+	movl	%ebx, 4(%ebp)
+
+	/* Enable paging to see if encryption is active */
+	movl	%cr0, %edx			 /* Backup %cr0 in %edx */
+	movl	$(X86_CR0_PG | X86_CR0_PE), %ecx /* Enable Paging and Protected mode */
+	movl	%ecx, %cr0
+
+	cmpl	%eax, 0(%ebp)
+	jne	3f
+	cmpl	%ebx, 4(%ebp)
+	jne	3f
+
+	movl	%edx, %cr0	/* Restore previous %cr0 */
+
+	jmp	4f
+
+3:	/* Check failed - hlt the machine */
+	hlt
+	jmp	3b
+
+4:
+	popl	%ebp
+	popl	%ebx
+	RET
+SYM_FUNC_END(startup32_check_sev_cbit)
+
+	.code64
+
+#include "../../kernel/sev_verify_cbit.S"
+
+	.data
+
+	.balign	8
+SYM_DATA(sme_me_mask,		.quad 0)
+SYM_DATA(sev_status,		.quad 0)
+SYM_DATA(sev_check_data,	.quad 0)
+
+SYM_DATA_START_LOCAL(boot32_idt)
+	.rept	32
+	.quad	0
+	.endr
+SYM_DATA_END(boot32_idt)
+
+SYM_DATA_START_LOCAL(boot32_idt_desc)
+	.word	. - boot32_idt - 1
+	.long	0
+SYM_DATA_END(boot32_idt_desc)

linux-7.2.3/arch/x86/boot/compressed/misc.c

@@ -0,0 +1,537 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * misc.c
+ *
+ * This is a collection of several routines used to extract the kernel
+ * which includes KASLR relocation, decompression, ELF parsing, and
+ * relocation processing. Additionally included are the screen and serial
+ * output functions and related debugging support functions.
+ *
+ * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
+ * puts by Nick Holloway 1993, better puts by Martin Mares 1995
+ * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
+ */
+
+#include "misc.h"
+#include "error.h"
+#include "../string.h"
+#include "../voffset.h"
+#include <asm/bootparam_utils.h>
+
+/*
+ * WARNING!!
+ * This code is compiled with -fPIC and it is relocated dynamically at
+ * run time, but no relocation processing is performed. This means that
+ * it is not safe to place pointers in static structures.
+ */
+
+/* Macros used by the included decompressor code below. */
+#define STATIC		static
+/* Define an externally visible malloc()/free(). */
+#define MALLOC_VISIBLE
+#include <linux/decompress/mm.h>
+
+/*
+ * Provide definitions of memzero and memmove as some of the decompressors will
+ * try to define their own functions if these are not defined as macros.
+ */
+#define memzero(s, n)	memset((s), 0, (n))
+#ifndef memmove
+#define memmove		memmove
+/* Functions used by the included decompressor code below. */
+void *memmove(void *dest, const void *src, size_t n);
+#endif
+
+/*
+ * This is set up by the setup-routine at boot-time
+ */
+struct boot_params *boot_params_ptr;
+
+struct port_io_ops pio_ops;
+
+memptr free_mem_ptr;
+memptr free_mem_end_ptr;
+int spurious_nmi_count;
+
+static char *vidmem;
+static int vidport;
+
+/* These might be accessed before .bss is cleared, so use .data instead. */
+static int lines __section(".data");
+static int cols __section(".data");
+
+#ifdef CONFIG_KERNEL_GZIP
+#include "../../../../lib/decompress_inflate.c"
+#endif
+
+#ifdef CONFIG_KERNEL_BZIP2
+#include "../../../../lib/decompress_bunzip2.c"
+#endif
+
+#ifdef CONFIG_KERNEL_LZMA
+#include "../../../../lib/decompress_unlzma.c"
+#endif
+
+#ifdef CONFIG_KERNEL_XZ
+#include "../../../../lib/decompress_unxz.c"
+#endif
+
+#ifdef CONFIG_KERNEL_LZO
+#include "../../../../lib/decompress_unlzo.c"
+#endif
+
+#ifdef CONFIG_KERNEL_LZ4
+#include "../../../../lib/decompress_unlz4.c"
+#endif
+
+#ifdef CONFIG_KERNEL_ZSTD
+#include "../../../../lib/decompress_unzstd.c"
+#endif
+/*
+ * NOTE: When adding a new decompressor, please update the analysis in
+ * ../header.S.
+ */
+
+static void scroll(void)
+{
+	int i;
+
+	memmove(vidmem, vidmem + cols * 2, (lines - 1) * cols * 2);
+	for (i = (lines - 1) * cols * 2; i < lines * cols * 2; i += 2)
+		vidmem[i] = ' ';
+}
+
+#define XMTRDY          0x20
+
+#define TXR             0       /*  Transmit register (WRITE) */
+#define LSR             5       /*  Line Status               */
+static void serial_putchar(int ch)
+{
+	unsigned timeout = 0xffff;
+
+	while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout)
+		cpu_relax();
+
+	outb(ch, early_serial_base + TXR);
+}
+
+void __putstr(const char *s)
+{
+	int x, y, pos;
+	char c;
+
+	if (early_serial_base) {
+		const char *str = s;
+		while (*str) {
+			if (*str == '\n')
+				serial_putchar('\r');
+			serial_putchar(*str++);
+		}
+	}
+
+	if (lines == 0 || cols == 0)
+		return;
+
+	x = boot_params_ptr->screen_info.orig_x;
+	y = boot_params_ptr->screen_info.orig_y;
+
+	while ((c = *s++) != '\0') {
+		if (c == '\n') {
+			x = 0;
+			if (++y >= lines) {
+				scroll();
+				y--;
+			}
+		} else {
+			vidmem[(x + cols * y) * 2] = c;
+			if (++x >= cols) {
+				x = 0;
+				if (++y >= lines) {
+					scroll();
+					y--;
+				}
+			}
+		}
+	}
+
+	boot_params_ptr->screen_info.orig_x = x;
+	boot_params_ptr->screen_info.orig_y = y;
+
+	pos = (x + cols * y) * 2;	/* Update cursor position */
+	outb(14, vidport);
+	outb(0xff & (pos >> 9), vidport+1);
+	outb(15, vidport);
+	outb(0xff & (pos >> 1), vidport+1);
+}
+
+static noinline void __putnum(unsigned long value, unsigned int base,
+			      int mindig)
+{
+	char buf[8*sizeof(value)+1];
+	char *p;
+
+	p = buf + sizeof(buf);
+	*--p = '\0';
+
+	while (mindig-- > 0 || value) {
+		unsigned char digit = value % base;
+		digit += (digit >= 10) ? ('a'-10) : '0';
+		*--p = digit;
+
+		value /= base;
+	}
+
+	__putstr(p);
+}
+
+void __puthex(unsigned long value)
+{
+	__putnum(value, 16, sizeof(value)*2);
+}
+
+void __putdec(unsigned long value)
+{
+	__putnum(value, 10, 1);
+}
+
+#ifdef CONFIG_X86_NEED_RELOCS
+static void handle_relocations(void *output, unsigned long output_len,
+			       unsigned long virt_addr)
+{
+	int *reloc;
+	unsigned long delta, map, ptr;
+	unsigned long min_addr = (unsigned long)output;
+	unsigned long max_addr = min_addr + (VO___bss_start - VO__text);
+
+	/*
+	 * Calculate the delta between where vmlinux was linked to load
+	 * and where it was actually loaded.
+	 */
+	delta = min_addr - LOAD_PHYSICAL_ADDR;
+
+	/*
+	 * The kernel contains a table of relocation addresses. Those
+	 * addresses have the final load address of the kernel in virtual
+	 * memory. We are currently working in the self map. So we need to
+	 * create an adjustment for kernel memory addresses to the self map.
+	 * This will involve subtracting out the base address of the kernel.
+	 */
+	map = delta - __START_KERNEL_map;
+
+	/*
+	 * 32-bit always performs relocations. 64-bit relocations are only
+	 * needed if KASLR has chosen a different starting address offset
+	 * from __START_KERNEL_map.
+	 */
+	if (IS_ENABLED(CONFIG_X86_64))
+		delta = virt_addr - LOAD_PHYSICAL_ADDR;
+
+	if (!delta) {
+		debug_putstr("No relocation needed... ");
+		return;
+	}
+	debug_putstr("Performing relocations... ");
+
+	/*
+	 * Process relocations: 32 bit relocations first then 64 bit after.
+	 * Two sets of binary relocations are added to the end of the kernel
+	 * before compression. Each relocation table entry is the kernel
+	 * address of the location which needs to be updated stored as a
+	 * 32-bit value which is sign extended to 64 bits.
+	 *
+	 * Format is:
+	 *
+	 * kernel bits...
+	 * 0 - zero terminator for 64 bit relocations
+	 * 64 bit relocation repeated
+	 * 0 - zero terminator for 32 bit relocations
+	 * 32 bit relocation repeated
+	 *
+	 * So we work backwards from the end of the decompressed image.
+	 */
+	for (reloc = output + output_len - sizeof(*reloc); *reloc; reloc--) {
+		long extended = *reloc;
+		extended += map;
+
+		ptr = (unsigned long)extended;
+		if (ptr < min_addr || ptr > max_addr)
+			error("32-bit relocation outside of kernel!\n");
+
+		*(uint32_t *)ptr += delta;
+	}
+#ifdef CONFIG_X86_64
+	for (reloc--; *reloc; reloc--) {
+		long extended = *reloc;
+		extended += map;
+
+		ptr = (unsigned long)extended;
+		if (ptr < min_addr || ptr > max_addr)
+			error("64-bit relocation outside of kernel!\n");
+
+		*(uint64_t *)ptr += delta;
+	}
+#endif
+}
+#else
+static inline void handle_relocations(void *output, unsigned long output_len,
+				      unsigned long virt_addr)
+{ }
+#endif
+
+static size_t parse_elf(void *output)
+{
+#ifdef CONFIG_X86_64
+	Elf64_Ehdr ehdr;
+	Elf64_Phdr *phdrs, *phdr;
+#else
+	Elf32_Ehdr ehdr;
+	Elf32_Phdr *phdrs, *phdr;
+#endif
+	void *dest;
+	int i;
+
+	memcpy(&ehdr, output, sizeof(ehdr));
+	if (ehdr.e_ident[EI_MAG0] != ELFMAG0 ||
+	   ehdr.e_ident[EI_MAG1] != ELFMAG1 ||
+	   ehdr.e_ident[EI_MAG2] != ELFMAG2 ||
+	   ehdr.e_ident[EI_MAG3] != ELFMAG3)
+		error("Kernel is not a valid ELF file");
+
+	debug_putstr("Parsing ELF... ");
+
+	phdrs = malloc(sizeof(*phdrs) * ehdr.e_phnum);
+	if (!phdrs)
+		error("Failed to allocate space for phdrs");
+
+	memcpy(phdrs, output + ehdr.e_phoff, sizeof(*phdrs) * ehdr.e_phnum);
+
+	for (i = 0; i < ehdr.e_phnum; i++) {
+		phdr = &phdrs[i];
+
+		switch (phdr->p_type) {
+		case PT_LOAD:
+#ifdef CONFIG_X86_64
+			if ((phdr->p_align % 0x200000) != 0)
+				error("Alignment of LOAD segment isn't multiple of 2MB");
+#endif
+#ifdef CONFIG_RELOCATABLE
+			dest = output;
+			dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR);
+#else
+			dest = (void *)(phdr->p_paddr);
+#endif
+			memmove(dest, output + phdr->p_offset, phdr->p_filesz);
+			break;
+		default: /* Ignore other PT_* */ break;
+		}
+	}
+
+	free(phdrs);
+
+	return ehdr.e_entry - LOAD_PHYSICAL_ADDR;
+}
+
+const unsigned long kernel_text_size = VO___start_rodata - VO__text;
+const unsigned long kernel_inittext_offset = VO__sinittext - VO__text;
+const unsigned long kernel_inittext_size = VO___inittext_end - VO__sinittext;
+const unsigned long kernel_total_size = VO__end - VO__text;
+
+static u8 boot_heap[BOOT_HEAP_SIZE] __aligned(4);
+
+extern unsigned char input_data[];
+extern unsigned int input_len, output_len;
+
+unsigned long decompress_kernel(unsigned char *outbuf, unsigned long virt_addr,
+				void (*error)(char *x))
+{
+	unsigned long entry;
+
+	if (!free_mem_ptr) {
+		free_mem_ptr     = (unsigned long)boot_heap;
+		free_mem_end_ptr = (unsigned long)boot_heap + sizeof(boot_heap);
+	}
+
+	if (__decompress(input_data, input_len, NULL, NULL, outbuf, output_len,
+			 NULL, error) < 0)
+		return ULONG_MAX;
+
+	entry = parse_elf(outbuf);
+	handle_relocations(outbuf, output_len, virt_addr);
+
+	return entry;
+}
+
+/*
+ * Set the memory encryption xloadflag based on the mem_encrypt= command line
+ * parameter, if provided.
+ */
+static void parse_mem_encrypt(struct setup_header *hdr)
+{
+	int on = cmdline_find_option_bool("mem_encrypt=on");
+	int off = cmdline_find_option_bool("mem_encrypt=off");
+
+	if (on > off)
+		hdr->xloadflags |= XLF_MEM_ENCRYPTION;
+}
+
+static void early_sev_detect(void)
+{
+	/*
+	 * Accessing video memory causes guest termination because
+	 * the boot stage2 #VC handler of SEV-ES/SNP guests does not
+	 * support MMIO handling and kexec -c adds screen_info to the
+	 * boot parameters passed to the kexec kernel, which causes
+	 * console output to be dumped to both video and serial.
+	 */
+	if (sev_status & MSR_AMD64_SEV_ES_ENABLED)
+		lines = cols = 0;
+}
+
+/*
+ * The compressed kernel image (ZO), has been moved so that its position
+ * is against the end of the buffer used to hold the uncompressed kernel
+ * image (VO) and the execution environment (.bss, .brk), which makes sure
+ * there is room to do the in-place decompression. (See header.S for the
+ * calculations.)
+ *
+ *                             |-----compressed kernel image------|
+ *                             V                                  V
+ * 0                       extract_offset                      +INIT_SIZE
+ * |-----------|---------------|-------------------------|--------|
+ *             |               |                         |        |
+ *           VO__text      startup_32 of ZO          VO__end    ZO__end
+ *             ^                                         ^
+ *             |-------uncompressed kernel image---------|
+ *
+ */
+asmlinkage __visible void *extract_kernel(void *rmode, unsigned char *output)
+{
+	unsigned long virt_addr = LOAD_PHYSICAL_ADDR;
+	memptr heap = (memptr)boot_heap;
+	unsigned long needed_size;
+	size_t entry_offset;
+
+	/* Retain x86 boot parameters pointer passed from startup_32/64. */
+	boot_params_ptr = rmode;
+
+	/* Clear flags intended for solely in-kernel use. */
+	boot_params_ptr->hdr.loadflags &= ~KASLR_FLAG;
+
+	parse_mem_encrypt(&boot_params_ptr->hdr);
+
+	sanitize_boot_params(boot_params_ptr);
+
+	if (boot_params_ptr->screen_info.orig_video_mode == 7) {
+		vidmem = (char *) 0xb0000;
+		vidport = 0x3b4;
+	} else {
+		vidmem = (char *) 0xb8000;
+		vidport = 0x3d4;
+	}
+
+	lines = boot_params_ptr->screen_info.orig_video_lines;
+	cols = boot_params_ptr->screen_info.orig_video_cols;
+
+	init_default_io_ops();
+
+	/*
+	 * Detect TDX guest environment.
+	 *
+	 * It has to be done before console_init() in order to use
+	 * paravirtualized port I/O operations if needed.
+	 */
+	early_tdx_detect();
+
+	early_sev_detect();
+
+	console_init();
+
+	/*
+	 * Save RSDP address for later use. Have this after console_init()
+	 * so that early debugging output from the RSDP parsing code can be
+	 * collected.
+	 */
+	boot_params_ptr->acpi_rsdp_addr = get_rsdp_addr();
+
+	debug_putstr("early console in extract_kernel\n");
+
+	free_mem_ptr     = heap;	/* Heap */
+	free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
+
+	/*
+	 * The memory hole needed for the kernel is the larger of either
+	 * the entire decompressed kernel plus relocation table, or the
+	 * entire decompressed kernel plus .bss and .brk sections.
+	 *
+	 * On X86_64, the memory is mapped with PMD pages. Round the
+	 * size up so that the full extent of PMD pages mapped is
+	 * included in the check against the valid memory table
+	 * entries. This ensures the full mapped area is usable RAM
+	 * and doesn't include any reserved areas.
+	 */
+	needed_size = max_t(unsigned long, output_len, kernel_total_size);
+#ifdef CONFIG_X86_64
+	needed_size = ALIGN(needed_size, MIN_KERNEL_ALIGN);
+#endif
+
+	/* Report initial kernel position details. */
+	debug_putaddr(input_data);
+	debug_putaddr(input_len);
+	debug_putaddr(output);
+	debug_putaddr(output_len);
+	debug_putaddr(kernel_total_size);
+	debug_putaddr(needed_size);
+
+#ifdef CONFIG_X86_64
+	/* Report address of 32-bit trampoline */
+	debug_putaddr(trampoline_32bit);
+#endif
+
+	choose_random_location((unsigned long)input_data, input_len,
+				(unsigned long *)&output,
+				needed_size,
+				&virt_addr);
+
+	/* Validate memory location choices. */
+	if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1))
+		error("Destination physical address inappropriately aligned");
+	if (virt_addr & (MIN_KERNEL_ALIGN - 1))
+		error("Destination virtual address inappropriately aligned");
+#ifdef CONFIG_X86_64
+	if (heap > 0x3fffffffffffUL)
+		error("Destination address too large");
+	if (virt_addr + needed_size > KERNEL_IMAGE_SIZE)
+		error("Destination virtual address is beyond the kernel mapping area");
+#else
+	if (heap > ((-__PAGE_OFFSET-(128<<20)-1) & 0x7fffffff))
+		error("Destination address too large");
+#endif
+#ifndef CONFIG_RELOCATABLE
+	if (virt_addr != LOAD_PHYSICAL_ADDR)
+		error("Destination virtual address changed when not relocatable");
+#endif
+
+	debug_putstr("\nDecompressing Linux... ");
+
+	if (init_unaccepted_memory()) {
+		debug_putstr("Accepting memory... ");
+		accept_memory(__pa(output), needed_size);
+	}
+
+	entry_offset = decompress_kernel(output, virt_addr, error);
+
+	debug_putstr("done.\nBooting the kernel (entry_offset: 0x");
+	debug_puthex(entry_offset);
+	debug_putstr(").\n");
+
+	/* Disable exception handling before booting the kernel */
+	cleanup_exception_handling();
+
+	if (spurious_nmi_count) {
+		error_putstr("Spurious early NMIs ignored: ");
+		error_putdec(spurious_nmi_count);
+		error_putstr("\n");
+	}
+
+	return output + entry_offset;
+}

linux-7.2.3/arch/x86/boot/compressed/misc.h

@@ -0,0 +1,259 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BOOT_COMPRESSED_MISC_H
+#define BOOT_COMPRESSED_MISC_H
+
+/*
+ * Special hack: we have to be careful, because no indirections are allowed here,
+ * and paravirt_ops is a kind of one. As it will only run in baremetal anyway,
+ * we just keep it from happening. (This list needs to be extended when new
+ * paravirt and debugging variants are added.)
+ */
+#undef CONFIG_PARAVIRT
+#undef CONFIG_PARAVIRT_XXL
+#undef CONFIG_PARAVIRT_SPINLOCKS
+#undef CONFIG_ARCH_HAS_LAZY_MMU_MODE
+#undef CONFIG_KASAN
+#undef CONFIG_KASAN_GENERIC
+
+#define __NO_FORTIFY
+
+/* cpu_feature_enabled() cannot be used this early */
+#define USE_EARLY_PGTABLE_L5
+
+/*
+ * Boot stub deals with identity mappings, physical and virtual addresses are
+ * the same, so override these defines.
+ *
+ * <asm/page.h> will not define them if they are already defined.
+ */
+#define __pa(x)  ((unsigned long)(x))
+#define __va(x)  ((void *)((unsigned long)(x)))
+
+#include <linux/linkage.h>
+#include <linux/screen_info.h>
+#include <linux/elf.h>
+#include <asm/page.h>
+#include <asm/boot.h>
+#include <asm/bootparam.h>
+#include <asm/desc_defs.h>
+
+#include "tdx.h"
+
+#define BOOT_CTYPE_H
+#include <linux/acpi.h>
+
+#define BOOT_BOOT_H
+#include "../ctype.h"
+#include "../io.h"
+
+#include "efi.h"
+
+#ifdef CONFIG_X86_64
+#define memptr long
+#else
+#define memptr unsigned
+#endif
+
+/* boot/compressed/vmlinux start and end markers */
+extern char _head[], _end[];
+
+/* misc.c */
+extern memptr free_mem_ptr;
+extern memptr free_mem_end_ptr;
+extern int spurious_nmi_count;
+void *malloc(int size);
+void free(void *where);
+void __putstr(const char *s);
+void __puthex(unsigned long value);
+void __putdec(unsigned long value);
+#define error_putstr(__x)  __putstr(__x)
+#define error_puthex(__x)  __puthex(__x)
+#define error_putdec(__x)  __putdec(__x)
+
+#ifdef CONFIG_X86_VERBOSE_BOOTUP
+
+#define debug_putstr(__x)  __putstr(__x)
+#define debug_puthex(__x)  __puthex(__x)
+#define debug_putaddr(__x) { \
+		debug_putstr(#__x ": 0x"); \
+		debug_puthex((unsigned long)(__x)); \
+		debug_putstr("\n"); \
+	}
+
+#else
+
+static inline void debug_putstr(const char *s)
+{ }
+static inline void debug_puthex(unsigned long value)
+{ }
+#define debug_putaddr(x) /* */
+
+#endif
+
+/* cmdline.c */
+int cmdline_find_option(const char *option, char *buffer, int bufsize);
+int cmdline_find_option_bool(const char *option);
+
+struct mem_vector {
+	u64 start;
+	u64 size;
+};
+
+#ifdef CONFIG_RANDOMIZE_BASE
+/* kaslr.c */
+void choose_random_location(unsigned long input,
+			    unsigned long input_size,
+			    unsigned long *output,
+			    unsigned long output_size,
+			    unsigned long *virt_addr);
+#else
+static inline void choose_random_location(unsigned long input,
+					  unsigned long input_size,
+					  unsigned long *output,
+					  unsigned long output_size,
+					  unsigned long *virt_addr)
+{
+}
+#endif
+
+/* cpuflags.c */
+bool has_cpuflag(int flag);
+
+#ifdef CONFIG_X86_64
+extern int set_page_decrypted(unsigned long address);
+extern int set_page_encrypted(unsigned long address);
+extern int set_page_non_present(unsigned long address);
+extern unsigned char _pgtable[];
+#endif
+
+#ifdef CONFIG_EARLY_PRINTK
+/* early_serial_console.c */
+extern int early_serial_base;
+void console_init(void);
+#else
+static const int early_serial_base;
+static inline void console_init(void)
+{ }
+#endif
+
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+struct es_em_ctxt;
+struct insn;
+
+void sev_enable(struct boot_params *bp);
+void snp_check_features(void);
+void sev_es_shutdown_ghcb(void);
+extern bool sev_es_check_ghcb_fault(unsigned long address);
+void snp_set_page_private(unsigned long paddr);
+void snp_set_page_shared(unsigned long paddr);
+void sev_prep_identity_maps(unsigned long top_level_pgt);
+
+enum es_result vc_decode_insn(struct es_em_ctxt *ctxt);
+bool insn_has_rep_prefix(struct insn *insn);
+void sev_insn_decode_init(void);
+bool early_setup_ghcb(void);
+#else
+static inline void snp_check_features(void) { }
+static inline void sev_es_shutdown_ghcb(void) { }
+static inline bool sev_es_check_ghcb_fault(unsigned long address)
+{
+	return false;
+}
+static inline void snp_set_page_private(unsigned long paddr) { }
+static inline void snp_set_page_shared(unsigned long paddr) { }
+static inline void sev_prep_identity_maps(unsigned long top_level_pgt) { }
+#endif
+
+/* acpi.c */
+#ifdef CONFIG_ACPI
+acpi_physical_address get_rsdp_addr(void);
+#else
+static inline acpi_physical_address get_rsdp_addr(void) { return 0; }
+#endif
+
+#if defined(CONFIG_RANDOMIZE_BASE) && defined(CONFIG_MEMORY_HOTREMOVE) && defined(CONFIG_ACPI)
+extern struct mem_vector immovable_mem[MAX_NUMNODES*2];
+int count_immovable_mem_regions(void);
+#else
+static inline int count_immovable_mem_regions(void) { return 0; }
+#endif
+
+/* ident_map_64.c */
+extern unsigned int __pgtable_l5_enabled, pgdir_shift, ptrs_per_p4d;
+extern void kernel_add_identity_map(unsigned long start, unsigned long end);
+
+/* Used by PAGE_KERN* macros: */
+extern pteval_t __default_kernel_pte_mask;
+
+/* idt_64.c */
+extern gate_desc boot_idt[BOOT_IDT_ENTRIES];
+extern struct desc_ptr boot_idt_desc;
+
+#ifdef CONFIG_X86_64
+void cleanup_exception_handling(void);
+#else
+static inline void cleanup_exception_handling(void) { }
+#endif
+
+/* IDT Entry Points */
+void boot_page_fault(void);
+void boot_nmi_trap(void);
+void boot_stage1_vc(void);
+void boot_stage2_vc(void);
+
+unsigned long sev_verify_cbit(unsigned long cr3);
+
+enum efi_type {
+	EFI_TYPE_64,
+	EFI_TYPE_32,
+	EFI_TYPE_NONE,
+};
+
+#ifdef CONFIG_EFI
+/* helpers for early EFI config table access */
+enum efi_type efi_get_type(struct boot_params *bp);
+unsigned long efi_get_system_table(struct boot_params *bp);
+int efi_get_conf_table(struct boot_params *bp, unsigned long *cfg_tbl_pa,
+		       unsigned int *cfg_tbl_len);
+unsigned long efi_find_vendor_table(struct boot_params *bp,
+				    unsigned long cfg_tbl_pa,
+				    unsigned int cfg_tbl_len,
+				    efi_guid_t guid);
+#else
+static inline enum efi_type efi_get_type(struct boot_params *bp)
+{
+	return EFI_TYPE_NONE;
+}
+
+static inline unsigned long efi_get_system_table(struct boot_params *bp)
+{
+	return 0;
+}
+
+static inline int efi_get_conf_table(struct boot_params *bp,
+				     unsigned long *cfg_tbl_pa,
+				     unsigned int *cfg_tbl_len)
+{
+	return -ENOENT;
+}
+
+static inline unsigned long efi_find_vendor_table(struct boot_params *bp,
+						  unsigned long cfg_tbl_pa,
+						  unsigned int cfg_tbl_len,
+						  efi_guid_t guid)
+{
+	return 0;
+}
+#endif /* CONFIG_EFI */
+
+#ifdef CONFIG_UNACCEPTED_MEMORY
+bool init_unaccepted_memory(void);
+#else
+static inline bool init_unaccepted_memory(void) { return false; }
+#endif
+
+/* Defined in EFI stub */
+extern struct efi_unaccepted_memory *unaccepted_table;
+void accept_memory(phys_addr_t start, unsigned long size);
+
+#endif /* BOOT_COMPRESSED_MISC_H */

linux-7.2.3/arch/x86/boot/compressed/mkpiggy.c

@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* ----------------------------------------------------------------------- *
+ *
+ *  Copyright (C) 2009 Intel Corporation. All rights reserved.
+ *
+ *  H. Peter Anvin <hpa@linux.intel.com>
+ *
+ * -----------------------------------------------------------------------
+ *
+ * Outputs a small assembly wrapper with the appropriate symbols defined.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <inttypes.h>
+#include <tools/le_byteshift.h>
+
+int main(int argc, char *argv[])
+{
+	uint32_t olen;
+	long ilen;
+	FILE *f = NULL;
+	int retval = 1;
+
+	if (argc < 2) {
+		fprintf(stderr, "Usage: %s compressed_file\n", argv[0]);
+		goto bail;
+	}
+
+	/* Get the information for the compressed kernel image first */
+
+	f = fopen(argv[1], "r");
+	if (!f) {
+		perror(argv[1]);
+		goto bail;
+	}
+
+
+	if (fseek(f, -4L, SEEK_END)) {
+		perror(argv[1]);
+	}
+
+	if (fread(&olen, sizeof(olen), 1, f) != 1) {
+		perror(argv[1]);
+		goto bail;
+	}
+
+	ilen = ftell(f);
+	olen = get_unaligned_le32(&olen);
+
+	printf(".section \".rodata..compressed\",\"a\",@progbits\n");
+	printf(".globl z_input_len\n");
+	printf("z_input_len = %lu\n", ilen);
+	printf(".globl z_output_len\n");
+	printf("z_output_len = %lu\n", (unsigned long)olen);
+
+	printf(".globl input_data, input_data_end\n");
+	printf("input_data:\n");
+	printf(".incbin \"%s\"\n", argv[1]);
+	printf("input_data_end:\n");
+
+	printf(".section \".rodata\",\"a\",@progbits\n");
+	printf(".globl input_len\n");
+	printf("input_len:\n\t.long %lu\n", ilen);
+	printf(".globl output_len\n");
+	printf("output_len:\n\t.long %lu\n", (unsigned long)olen);
+
+	retval = 0;
+bail:
+	if (f)
+		fclose(f);
+	return retval;
+}

linux-7.2.3/arch/x86/boot/compressed/pgtable_64.c

@@ -0,0 +1,201 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "misc.h"
+#include <asm/bootparam.h>
+#include <asm/bootparam_utils.h>
+#include <asm/cpuid/api.h>
+#include <asm/e820/types.h>
+#include <asm/pgtable.h>
+#include <asm/processor.h>
+#include "../string.h"
+#include "efi.h"
+
+#define BIOS_START_MIN		0x20000U	/* 128K, less than this is insane */
+#define BIOS_START_MAX		0x9f000U	/* 640K, absolute maximum */
+
+/* __pgtable_l5_enabled needs to be in .data to avoid being cleared along with .bss */
+unsigned int __section(".data") __pgtable_l5_enabled;
+unsigned int __section(".data") pgdir_shift = 39;
+unsigned int __section(".data") ptrs_per_p4d = 1;
+
+/* Buffer to preserve trampoline memory */
+static char trampoline_save[TRAMPOLINE_32BIT_SIZE];
+
+/*
+ * Trampoline address will be printed by extract_kernel() for debugging
+ * purposes.
+ *
+ * Avoid putting the pointer into .bss as it will be cleared between
+ * configure_5level_paging() and extract_kernel().
+ */
+unsigned long *trampoline_32bit __section(".data");
+
+int cmdline_find_option_bool(const char *option);
+
+static unsigned long find_trampoline_placement(void)
+{
+	unsigned long bios_start = 0, ebda_start = 0;
+	struct boot_e820_entry *entry;
+	char *signature;
+	int i;
+
+	/*
+	 * Find a suitable spot for the trampoline.
+	 * This code is based on reserve_bios_regions().
+	 */
+
+	/*
+	 * EFI systems may not provide legacy ROM. The memory may not be mapped
+	 * at all.
+	 *
+	 * Only look for values in the legacy ROM for non-EFI system.
+	 */
+	signature = (char *)&boot_params_ptr->efi_info.efi_loader_signature;
+	if (strncmp(signature, EFI32_LOADER_SIGNATURE, 4) &&
+	    strncmp(signature, EFI64_LOADER_SIGNATURE, 4)) {
+		ebda_start = *(unsigned short *)0x40e << 4;
+		bios_start = *(unsigned short *)0x413 << 10;
+	}
+
+	if (bios_start < BIOS_START_MIN || bios_start > BIOS_START_MAX)
+		bios_start = BIOS_START_MAX;
+
+	if (ebda_start > BIOS_START_MIN && ebda_start < bios_start)
+		bios_start = ebda_start;
+
+	bios_start = round_down(bios_start, PAGE_SIZE);
+
+	/* Find the first usable memory region under bios_start. */
+	for (i = boot_params_ptr->e820_entries - 1; i >= 0; i--) {
+		unsigned long new = bios_start;
+
+		entry = &boot_params_ptr->e820_table[i];
+
+		/* Skip all entries above bios_start. */
+		if (bios_start <= entry->addr)
+			continue;
+
+		/* Skip non-RAM entries. */
+		if (entry->type != E820_TYPE_RAM)
+			continue;
+
+		/* Adjust bios_start to the end of the entry if needed. */
+		if (bios_start > entry->addr + entry->size)
+			new = entry->addr + entry->size;
+
+		/* Keep bios_start page-aligned. */
+		new = round_down(new, PAGE_SIZE);
+
+		/* Skip the entry if it's too small. */
+		if (new - TRAMPOLINE_32BIT_SIZE < entry->addr)
+			continue;
+
+		/* Protect against underflow. */
+		if (new - TRAMPOLINE_32BIT_SIZE > bios_start)
+			break;
+
+		bios_start = new;
+		break;
+	}
+
+	/* Place the trampoline just below the end of low memory */
+	return bios_start - TRAMPOLINE_32BIT_SIZE;
+}
+
+asmlinkage void configure_5level_paging(struct boot_params *bp, void *pgtable)
+{
+	void (*toggle_la57)(void *cr3);
+	bool l5_required = false;
+
+	/* Initialize boot_params. Required for cmdline_find_option_bool(). */
+	sanitize_boot_params(bp);
+	boot_params_ptr = bp;
+
+	/*
+	 * Check if LA57 is desired and supported.
+	 *
+	 * There are several parts to the check:
+	 *   - if user asked to disable 5-level paging: no5lvl in cmdline
+	 *   - if the machine supports 5-level paging:
+	 *     + CPUID leaf 7 is supported
+	 *     + the leaf has the feature bit set
+	 */
+	if (!cmdline_find_option_bool("no5lvl") &&
+	    native_cpuid_eax(0) >= 7 && (native_cpuid_ecx(7) & BIT(16))) {
+		l5_required = true;
+
+		/* Initialize variables for 5-level paging */
+		__pgtable_l5_enabled = 1;
+		pgdir_shift = 48;
+		ptrs_per_p4d = 512;
+	}
+
+	/*
+	 * The trampoline will not be used if the paging mode is already set to
+	 * the desired one.
+	 */
+	if (l5_required == !!(native_read_cr4() & X86_CR4_LA57))
+		return;
+
+	trampoline_32bit = (unsigned long *)find_trampoline_placement();
+
+	/* Preserve trampoline memory */
+	memcpy(trampoline_save, trampoline_32bit, TRAMPOLINE_32BIT_SIZE);
+
+	/* Clear trampoline memory first */
+	memset(trampoline_32bit, 0, TRAMPOLINE_32BIT_SIZE);
+
+	/* Copy trampoline code in place */
+	toggle_la57 = memcpy(trampoline_32bit +
+			TRAMPOLINE_32BIT_CODE_OFFSET / sizeof(unsigned long),
+			&trampoline_32bit_src, TRAMPOLINE_32BIT_CODE_SIZE);
+
+	/*
+	 * Avoid the need for a stack in the 32-bit trampoline code, by using
+	 * LJMP rather than LRET to return back to long mode. LJMP takes an
+	 * immediate absolute address, which needs to be adjusted based on the
+	 * placement of the trampoline.
+	 */
+	*(u32 *)((u8 *)toggle_la57 + trampoline_ljmp_imm_offset) +=
+						(unsigned long)toggle_la57;
+
+	/*
+	 * The code below prepares page table in trampoline memory.
+	 *
+	 * The new page table will be used by trampoline code for switching
+	 * from 4- to 5-level paging or vice versa.
+	 */
+
+	if (l5_required) {
+		/*
+		 * For 4- to 5-level paging transition, set up current CR3 as
+		 * the first and the only entry in a new top-level page table.
+		 */
+		*trampoline_32bit = native_read_cr3_pa() | _PAGE_TABLE_NOENC;
+	} else {
+		u64 *new_cr3;
+		pgd_t *pgdp;
+
+		/*
+		 * For 5- to 4-level paging transition, copy page table pointed
+		 * by first entry in the current top-level page table as our
+		 * new top-level page table.
+		 *
+		 * We cannot just point to the page table from trampoline as it
+		 * may be above 4G.
+		 */
+		pgdp = (pgd_t *)native_read_cr3_pa();
+		new_cr3 = (u64 *)(native_pgd_val(pgdp[0]) & PTE_PFN_MASK);
+		memcpy(trampoline_32bit, new_cr3, PAGE_SIZE);
+	}
+
+	toggle_la57(trampoline_32bit);
+
+	/*
+	 * Move the top level page table out of trampoline memory.
+	 */
+	memcpy(pgtable, trampoline_32bit, PAGE_SIZE);
+	native_write_cr3((unsigned long)pgtable);
+
+	/* Restore trampoline memory */
+	memcpy(trampoline_32bit, trampoline_save, TRAMPOLINE_32BIT_SIZE);
+}

linux-7.2.3/arch/x86/boot/compressed/sbat.S

@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Embed SBAT data in the kernel.
+ */
+	.pushsection ".sbat", "a", @progbits
+	.incbin CONFIG_EFI_SBAT_FILE
+	.popsection

linux-7.2.3/arch/x86/boot/compressed/sev-handle-vc.c

@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "misc.h"
+#include "error.h"
+#include "sev.h"
+
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <asm/insn.h>
+#include <asm/pgtable_types.h>
+#include <asm/ptrace.h>
+#include <asm/sev.h>
+#include <asm/trapnr.h>
+#include <asm/trap_pf.h>
+#include <asm/fpu/xcr.h>
+
+#define __BOOT_COMPRESSED
+#undef __init
+#define __init
+
+/* Basic instruction decoding support needed */
+#include "../../lib/inat.c"
+#include "../../lib/insn.c"
+
+/*
+ * Copy a version of this function here - insn-eval.c can't be used in
+ * pre-decompression code.
+ */
+bool insn_has_rep_prefix(struct insn *insn)
+{
+	insn_byte_t p;
+
+	insn_get_prefixes(insn);
+
+	for_each_insn_prefix(insn, p) {
+		if (p == 0xf2 || p == 0xf3)
+			return true;
+	}
+
+	return false;
+}
+
+enum es_result vc_decode_insn(struct es_em_ctxt *ctxt)
+{
+	char buffer[MAX_INSN_SIZE];
+	int ret;
+
+	memcpy(buffer, (unsigned char *)ctxt->regs->ip, MAX_INSN_SIZE);
+
+	ret = insn_decode(&ctxt->insn, buffer, MAX_INSN_SIZE, INSN_MODE_64);
+	if (ret < 0)
+		return ES_DECODE_FAILED;
+
+	return ES_OK;
+}
+
+extern void sev_insn_decode_init(void) __alias(inat_init_tables);
+
+/*
+ * Only a dummy for insn_get_seg_base() - Early boot-code is 64bit only and
+ * doesn't use segments.
+ */
+static unsigned long insn_get_seg_base(struct pt_regs *regs, int seg_reg_idx)
+{
+	return 0UL;
+}
+
+static enum es_result vc_write_mem(struct es_em_ctxt *ctxt,
+				   void *dst, char *buf, size_t size)
+{
+	memcpy(dst, buf, size);
+
+	return ES_OK;
+}
+
+static enum es_result vc_read_mem(struct es_em_ctxt *ctxt,
+				  void *src, char *buf, size_t size)
+{
+	memcpy(buf, src, size);
+
+	return ES_OK;
+}
+
+static enum es_result vc_ioio_check(struct es_em_ctxt *ctxt, u16 port, size_t size)
+{
+	return ES_OK;
+}
+
+static bool fault_in_kernel_space(unsigned long address)
+{
+	return false;
+}
+
+#define sev_printk(fmt, ...)
+
+#include "../../coco/sev/vc-shared.c"
+
+void do_boot_stage2_vc(struct pt_regs *regs, unsigned long exit_code)
+{
+	struct es_em_ctxt ctxt;
+	enum es_result result;
+
+	if (!boot_ghcb && !early_setup_ghcb())
+		sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
+
+	vc_ghcb_invalidate(boot_ghcb);
+	result = vc_init_em_ctxt(&ctxt, regs, exit_code);
+	if (result != ES_OK)
+		goto finish;
+
+	result = vc_check_opcode_bytes(&ctxt, exit_code);
+	if (result != ES_OK)
+		goto finish;
+
+	switch (exit_code) {
+	case SVM_EXIT_RDTSC:
+	case SVM_EXIT_RDTSCP:
+		result = vc_handle_rdtsc(boot_ghcb, &ctxt, exit_code);
+		break;
+	case SVM_EXIT_IOIO:
+		result = vc_handle_ioio(boot_ghcb, &ctxt);
+		break;
+	case SVM_EXIT_CPUID:
+		result = vc_handle_cpuid(boot_ghcb, &ctxt);
+		break;
+	default:
+		result = ES_UNSUPPORTED;
+		break;
+	}
+
+finish:
+	if (result == ES_OK)
+		vc_finish_insn(&ctxt);
+	else if (result != ES_RETRY)
+		sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
+}

linux-7.2.3/arch/x86/boot/compressed/sev.c

@@ -0,0 +1,513 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AMD Encrypted Register State Support
+ *
+ * Author: Joerg Roedel <jroedel@suse.de>
+ */
+
+/*
+ * misc.h needs to be first because it knows how to include the other kernel
+ * headers in the pre-decompression code in a way that does not break
+ * compilation.
+ */
+#include "misc.h"
+
+#include <asm/bootparam.h>
+#include <asm/pgtable_types.h>
+#include <asm/shared/msr.h>
+#include <asm/sev.h>
+#include <asm/trapnr.h>
+#include <asm/trap_pf.h>
+#include <asm/msr-index.h>
+#include <asm/fpu/xcr.h>
+#include <asm/ptrace.h>
+#include <asm/svm.h>
+#include <asm/cpuid/api.h>
+
+#include "error.h"
+#include "sev.h"
+
+static struct ghcb boot_ghcb_page __aligned(PAGE_SIZE);
+struct ghcb *boot_ghcb __section(".data");
+
+#undef __init
+#define __init
+
+#define __BOOT_COMPRESSED
+
+u8 snp_vmpl __section(".data");
+u16 ghcb_version __section(".data");
+
+u64 boot_svsm_caa_pa __section(".data");
+
+/* Include code for early handlers */
+#include "../../boot/startup/sev-shared.c"
+
+static bool sev_snp_enabled(void)
+{
+	return sev_status & MSR_AMD64_SEV_SNP_ENABLED;
+}
+
+void snp_set_page_private(unsigned long paddr)
+{
+	struct psc_desc d = {
+		SNP_PAGE_STATE_PRIVATE,
+		(struct svsm_ca *)boot_svsm_caa_pa,
+		boot_svsm_caa_pa
+	};
+
+	if (!sev_snp_enabled())
+		return;
+
+	__page_state_change(paddr, paddr, &d);
+}
+
+void snp_set_page_shared(unsigned long paddr)
+{
+	struct psc_desc d = {
+		SNP_PAGE_STATE_SHARED,
+		(struct svsm_ca *)boot_svsm_caa_pa,
+		boot_svsm_caa_pa
+	};
+
+	if (!sev_snp_enabled())
+		return;
+
+	__page_state_change(paddr, paddr, &d);
+}
+
+bool early_setup_ghcb(void)
+{
+	if (set_page_decrypted((unsigned long)&boot_ghcb_page))
+		return false;
+
+	/* Page is now mapped decrypted, clear it */
+	memset(&boot_ghcb_page, 0, sizeof(boot_ghcb_page));
+
+	boot_ghcb = &boot_ghcb_page;
+
+	/* Initialize lookup tables for the instruction decoder */
+	sev_insn_decode_init();
+
+	/* SNP guest requires the GHCB GPA must be registered */
+	if (sev_snp_enabled())
+		snp_register_ghcb_early(__pa(&boot_ghcb_page));
+
+	return true;
+}
+
+void snp_accept_memory(phys_addr_t start, phys_addr_t end)
+{
+	struct psc_desc d = {
+		SNP_PAGE_STATE_PRIVATE,
+		(struct svsm_ca *)boot_svsm_caa_pa,
+		boot_svsm_caa_pa
+	};
+
+	for (phys_addr_t pa = start; pa < end; pa += PAGE_SIZE)
+		__page_state_change(pa, pa, &d);
+}
+
+void sev_es_shutdown_ghcb(void)
+{
+	if (!boot_ghcb)
+		return;
+
+	if (!sev_es_check_cpu_features())
+		error("SEV-ES CPU Features missing.");
+
+	/*
+	 * This denotes whether to use the GHCB MSR protocol or the GHCB
+	 * shared page to perform a GHCB request. Since the GHCB page is
+	 * being changed to encrypted, it can't be used to perform GHCB
+	 * requests. Clear the boot_ghcb variable so that the GHCB MSR
+	 * protocol is used to change the GHCB page over to an encrypted
+	 * page.
+	 */
+	boot_ghcb = NULL;
+
+	/*
+	 * GHCB Page must be flushed from the cache and mapped encrypted again.
+	 * Otherwise the running kernel will see strange cache effects when
+	 * trying to use that page.
+	 */
+	if (set_page_encrypted((unsigned long)&boot_ghcb_page))
+		error("Can't map GHCB page encrypted");
+
+	/*
+	 * GHCB page is mapped encrypted again and flushed from the cache.
+	 * Mark it non-present now to catch bugs when #VC exceptions trigger
+	 * after this point.
+	 */
+	if (set_page_non_present((unsigned long)&boot_ghcb_page))
+		error("Can't unmap GHCB page");
+}
+
+static void __noreturn sev_es_ghcb_terminate(struct ghcb *ghcb, unsigned int set,
+					     unsigned int reason, u64 exit_info_2)
+{
+	u64 exit_info_1 = SVM_VMGEXIT_TERM_REASON(set, reason);
+
+	vc_ghcb_invalidate(ghcb);
+	ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_TERM_REQUEST);
+	ghcb_set_sw_exit_info_1(ghcb, exit_info_1);
+	ghcb_set_sw_exit_info_2(ghcb, exit_info_2);
+
+	sev_es_wr_ghcb_msr(__pa(ghcb));
+	VMGEXIT();
+
+	while (true)
+		asm volatile("hlt\n" : : : "memory");
+}
+
+bool sev_es_check_ghcb_fault(unsigned long address)
+{
+	/* Check whether the fault was on the GHCB page */
+	return ((address & PAGE_MASK) == (unsigned long)&boot_ghcb_page);
+}
+
+/*
+ * SNP_FEATURES_IMPL_REQ is the mask of SNP features that will need
+ * guest side implementation for proper functioning of the guest. If any
+ * of these features are enabled in the hypervisor but are lacking guest
+ * side implementation, the behavior of the guest will be undefined. The
+ * guest could fail in non-obvious way making it difficult to debug.
+ *
+ * As the behavior of reserved feature bits is unknown to be on the
+ * safe side add them to the required features mask.
+ */
+#define SNP_FEATURES_IMPL_REQ	(MSR_AMD64_SNP_VTOM |			\
+				 MSR_AMD64_SNP_REFLECT_VC |		\
+				 MSR_AMD64_SNP_RESTRICTED_INJ |		\
+				 MSR_AMD64_SNP_ALT_INJ |		\
+				 MSR_AMD64_SNP_DEBUG_SWAP |		\
+				 MSR_AMD64_SNP_VMPL_SSS |		\
+				 MSR_AMD64_SNP_SECURE_TSC |		\
+				 MSR_AMD64_SNP_VMGEXIT_PARAM |		\
+				 MSR_AMD64_SNP_VMSA_REG_PROT |		\
+				 MSR_AMD64_SNP_RESERVED_BIT13 |		\
+				 MSR_AMD64_SNP_RESERVED_BIT15 |		\
+				 MSR_AMD64_SNP_SECURE_AVIC |		\
+				 MSR_AMD64_SNP_RESERVED_BITS19_22 |	\
+				 MSR_AMD64_SNP_RESERVED_MASK)
+
+#ifdef CONFIG_AMD_SECURE_AVIC
+#define SNP_FEATURE_SECURE_AVIC		MSR_AMD64_SNP_SECURE_AVIC
+#else
+#define SNP_FEATURE_SECURE_AVIC		0
+#endif
+
+/*
+ * SNP_FEATURES_IMPL is the mask of SNP features that are implemented
+ * by the guest kernel. As and when a new feature is implemented in the
+ * guest kernel, a corresponding bit should be added to the mask.
+ */
+#define SNP_FEATURES_IMPL	(MSR_AMD64_SNP_DEBUG_SWAP |	\
+				 MSR_AMD64_SNP_SECURE_TSC |	\
+				 SNP_FEATURE_SECURE_AVIC)
+
+u64 snp_get_unsupported_features(u64 status)
+{
+	if (!(status & MSR_AMD64_SEV_SNP_ENABLED))
+		return 0;
+
+	return status & SNP_FEATURES_IMPL_REQ & ~SNP_FEATURES_IMPL;
+}
+
+void snp_check_features(void)
+{
+	u64 unsupported;
+
+	/*
+	 * Terminate the boot if hypervisor has enabled any feature lacking
+	 * guest side implementation. Pass on the unsupported features mask through
+	 * EXIT_INFO_2 of the GHCB protocol so that those features can be reported
+	 * as part of the guest boot failure.
+	 */
+	unsupported = snp_get_unsupported_features(sev_status);
+	if (unsupported) {
+		if (ghcb_version < 2 || (!boot_ghcb && !early_setup_ghcb()))
+			sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
+
+		sev_es_ghcb_terminate(boot_ghcb, SEV_TERM_SET_GEN,
+				      GHCB_SNP_UNSUPPORTED, unsupported);
+	}
+}
+
+/* Search for Confidential Computing blob in the EFI config table. */
+static struct cc_blob_sev_info *find_cc_blob_efi(struct boot_params *bp)
+{
+	unsigned long cfg_table_pa;
+	unsigned int cfg_table_len;
+	int ret;
+
+	ret = efi_get_conf_table(bp, &cfg_table_pa, &cfg_table_len);
+	if (ret)
+		return NULL;
+
+	return (struct cc_blob_sev_info *)efi_find_vendor_table(bp, cfg_table_pa,
+								cfg_table_len,
+								EFI_CC_BLOB_GUID);
+}
+
+/*
+ * Initial set up of SNP relies on information provided by the
+ * Confidential Computing blob, which can be passed to the boot kernel
+ * by firmware/bootloader in the following ways:
+ *
+ * - via an entry in the EFI config table
+ * - via a setup_data structure, as defined by the Linux Boot Protocol
+ *
+ * Scan for the blob in that order.
+ */
+static struct cc_blob_sev_info *find_cc_blob(struct boot_params *bp)
+{
+	struct cc_blob_sev_info *cc_info;
+
+	cc_info = find_cc_blob_efi(bp);
+	if (cc_info)
+		goto found_cc_info;
+
+	cc_info = find_cc_blob_setup_data(bp);
+	if (!cc_info)
+		return NULL;
+
+found_cc_info:
+	if (cc_info->magic != CC_BLOB_SEV_HDR_MAGIC)
+		sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
+
+	return cc_info;
+}
+
+/*
+ * Indicate SNP based on presence of SNP-specific CC blob. Subsequent checks
+ * will verify the SNP CPUID/MSR bits.
+ */
+static bool early_snp_init(struct boot_params *bp)
+{
+	struct cc_blob_sev_info *cc_info;
+
+	if (!bp)
+		return false;
+
+	cc_info = find_cc_blob(bp);
+	if (!cc_info)
+		return false;
+
+	/*
+	 * If a SNP-specific Confidential Computing blob is present, then
+	 * firmware/bootloader have indicated SNP support. Verifying this
+	 * involves CPUID checks which will be more reliable if the SNP
+	 * CPUID table is used. See comments over snp_setup_cpuid_table() for
+	 * more details.
+	 */
+	setup_cpuid_table(cc_info);
+
+	/*
+	 * Record the SVSM Calling Area (CA) address if the guest is not
+	 * running at VMPL0. The CA will be used to communicate with the
+	 * SVSM and request its services.
+	 */
+	svsm_setup_ca(cc_info, rip_rel_ptr(&boot_ghcb_page));
+
+	/*
+	 * Pass run-time kernel a pointer to CC info via boot_params so EFI
+	 * config table doesn't need to be searched again during early startup
+	 * phase.
+	 */
+	bp->cc_blob_address = (u32)(unsigned long)cc_info;
+
+	return true;
+}
+
+/*
+ * sev_check_cpu_support - Check for SEV support in the CPU capabilities
+ *
+ * Returns < 0 if SEV is not supported, otherwise the position of the
+ * encryption bit in the page table descriptors.
+ */
+static int sev_check_cpu_support(void)
+{
+	unsigned int eax, ebx, ecx, edx;
+
+	/* Check for the SME/SEV support leaf */
+	eax = 0x80000000;
+	ecx = 0;
+	native_cpuid(&eax, &ebx, &ecx, &edx);
+	if (eax < 0x8000001f)
+		return -ENODEV;
+
+	/*
+	 * Check for the SME/SEV feature:
+	 *   CPUID Fn8000_001F[EAX]
+	 *   - Bit 0 - Secure Memory Encryption support
+	 *   - Bit 1 - Secure Encrypted Virtualization support
+	 *   CPUID Fn8000_001F[EBX]
+	 *   - Bits 5:0 - Pagetable bit position used to indicate encryption
+	 */
+	eax = 0x8000001f;
+	ecx = 0;
+	native_cpuid(&eax, &ebx, &ecx, &edx);
+	/* Check whether SEV is supported */
+	if (!(eax & BIT(1)))
+		return -ENODEV;
+
+	sev_snp_needs_sfw = !(ebx & BIT(31));
+
+	return ebx & 0x3f;
+}
+
+void sev_enable(struct boot_params *bp)
+{
+	struct msr m;
+	int bitpos;
+	bool snp;
+
+	/*
+	 * bp->cc_blob_address should only be set by boot/compressed kernel.
+	 * Initialize it to 0 to ensure that uninitialized values from
+	 * buggy bootloaders aren't propagated.
+	 */
+	if (bp)
+		bp->cc_blob_address = 0;
+
+	/*
+	 * Do an initial SEV capability check before early_snp_init() which
+	 * loads the CPUID page and the same checks afterwards are done
+	 * without the hypervisor and are trustworthy.
+	 *
+	 * If the HV fakes SEV support, the guest will crash'n'burn
+	 * which is good enough.
+	 */
+
+	if (sev_check_cpu_support() < 0)
+		return;
+
+	/*
+	 * Setup/preliminary detection of SNP. This will be sanity-checked
+	 * against CPUID/MSR values later.
+	 */
+	snp = early_snp_init(bp);
+
+	/* Now repeat the checks with the SNP CPUID table. */
+
+	bitpos = sev_check_cpu_support();
+	if (bitpos < 0) {
+		if (snp)
+			error("SEV-SNP support indicated by CC blob, but not CPUID.");
+		return;
+	}
+
+	/* Set the SME mask if this is an SEV guest. */
+	raw_rdmsr(MSR_AMD64_SEV, &m);
+	sev_status = m.q;
+	if (!(sev_status & MSR_AMD64_SEV_ENABLED))
+		return;
+
+	/* Negotiate the GHCB protocol version. */
+	if (sev_status & MSR_AMD64_SEV_ES_ENABLED) {
+		if (!sev_es_negotiate_protocol())
+			sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_PROT_UNSUPPORTED);
+	}
+
+	/*
+	 * SNP is supported in v2 of the GHCB spec which mandates support for HV
+	 * features.
+	 */
+	if (sev_status & MSR_AMD64_SEV_SNP_ENABLED) {
+		u64 hv_features;
+
+		hv_features = get_hv_features();
+		if (!(hv_features & GHCB_HV_FT_SNP))
+			sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
+
+		/*
+		 * Running at VMPL0 is required unless an SVSM is present and
+		 * the hypervisor supports the required SVSM GHCB events.
+		 */
+		if (snp_vmpl && !(hv_features & GHCB_HV_FT_SNP_MULTI_VMPL))
+			sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_NOT_VMPL0);
+	}
+
+	if (snp && !(sev_status & MSR_AMD64_SEV_SNP_ENABLED))
+		error("SEV-SNP supported indicated by CC blob, but not SEV status MSR.");
+
+	sme_me_mask = BIT_ULL(bitpos);
+}
+
+/*
+ * sev_get_status - Retrieve the SEV status mask
+ *
+ * Returns 0 if the CPU is not SEV capable, otherwise the value of the
+ * AMD64_SEV MSR.
+ */
+u64 sev_get_status(void)
+{
+	struct msr m;
+
+	if (sev_check_cpu_support() < 0)
+		return 0;
+
+	raw_rdmsr(MSR_AMD64_SEV, &m);
+	return m.q;
+}
+
+void sev_prep_identity_maps(unsigned long top_level_pgt)
+{
+	/*
+	 * The Confidential Computing blob is used very early in uncompressed
+	 * kernel to find the in-memory CPUID table to handle CPUID
+	 * instructions. Make sure an identity-mapping exists so it can be
+	 * accessed after switchover.
+	 */
+	if (sev_snp_enabled()) {
+		unsigned long cc_info_pa = boot_params_ptr->cc_blob_address;
+		struct cc_blob_sev_info *cc_info;
+
+		kernel_add_identity_map(cc_info_pa, cc_info_pa + sizeof(*cc_info));
+
+		cc_info = (struct cc_blob_sev_info *)cc_info_pa;
+		kernel_add_identity_map(cc_info->cpuid_phys, cc_info->cpuid_phys + cc_info->cpuid_len);
+	}
+
+	sev_verify_cbit(top_level_pgt);
+}
+
+bool early_is_sevsnp_guest(void)
+{
+	static bool sevsnp;
+
+	if (sevsnp)
+		return true;
+
+	if (!(sev_get_status() & MSR_AMD64_SEV_SNP_ENABLED))
+		return false;
+
+	sevsnp = true;
+
+	if (!snp_vmpl) {
+		unsigned int eax, ebx, ecx, edx;
+
+		/*
+		 * CPUID Fn8000_001F_EAX[28] - SVSM support
+		 */
+		eax = 0x8000001f;
+		ecx = 0;
+		native_cpuid(&eax, &ebx, &ecx, &edx);
+		if (eax & BIT(28)) {
+			struct msr m;
+
+			/* Obtain the address of the calling area to use */
+			raw_rdmsr(MSR_SVSM_CAA, &m);
+			boot_svsm_caa_pa = m.q;
+
+			/*
+			 * The real VMPL level cannot be discovered, but the
+			 * memory acceptance routines make no use of that so
+			 * any non-zero value suffices here.
+			 */
+			snp_vmpl = U8_MAX;
+		}
+	}
+	return true;
+}

linux-7.2.3/arch/x86/boot/compressed/sev.h

@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * AMD SEV header for early boot related functions.
+ *
+ * Author: Tom Lendacky <thomas.lendacky@amd.com>
+ */
+
+#ifndef BOOT_COMPRESSED_SEV_H
+#define BOOT_COMPRESSED_SEV_H
+
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+
+#include <asm/shared/msr.h>
+
+void snp_accept_memory(phys_addr_t start, phys_addr_t end);
+u64 sev_get_status(void);
+bool early_is_sevsnp_guest(void);
+
+static inline u64 sev_es_rd_ghcb_msr(void)
+{
+	struct msr m;
+
+	raw_rdmsr(MSR_AMD64_SEV_ES_GHCB, &m);
+
+	return m.q;
+}
+
+static inline void sev_es_wr_ghcb_msr(u64 val)
+{
+	struct msr m;
+
+	m.q = val;
+	raw_wrmsr(MSR_AMD64_SEV_ES_GHCB, &m);
+}
+
+#else
+
+static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { }
+static inline u64 sev_get_status(void) { return 0; }
+static inline bool early_is_sevsnp_guest(void) { return false; }
+
+#endif
+
+#endif

linux-7.2.3/arch/x86/boot/compressed/string.c

@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This provides an optimized implementation of memcpy, and a simplified
+ * implementation of memset and memmove. These are used here because the
+ * standard kernel runtime versions are not yet available and we don't
+ * trust the gcc built-in implementations as they may do unexpected things
+ * (e.g. FPU ops) in the minimal decompression stub execution environment.
+ */
+#include "error.h"
+
+#include "../string.c"
+
+#ifdef CONFIG_X86_32
+static void *____memcpy(void *dest, const void *src, size_t n)
+{
+	int d0, d1, d2;
+	asm volatile(
+		"rep movsl\n\t"
+		"movl %4,%%ecx\n\t"
+		"rep movsb"
+		: "=&c" (d0), "=&D" (d1), "=&S" (d2)
+		: "0" (n >> 2), "g" (n & 3), "1" (dest), "2" (src)
+		: "memory");
+
+	return dest;
+}
+#else
+static void *____memcpy(void *dest, const void *src, size_t n)
+{
+	long d0, d1, d2;
+	asm volatile(
+		"rep movsq\n\t"
+		"movq %4,%%rcx\n\t"
+		"rep movsb"
+		: "=&c" (d0), "=&D" (d1), "=&S" (d2)
+		: "0" (n >> 3), "g" (n & 7), "1" (dest), "2" (src)
+		: "memory");
+
+	return dest;
+}
+#endif
+
+void *memset(void *s, int c, size_t n)
+{
+	int i;
+	char *ss = s;
+
+	for (i = 0; i < n; i++)
+		ss[i] = c;
+	return s;
+}
+
+void *memmove(void *dest, const void *src, size_t n)
+{
+	unsigned char *d = dest;
+	const unsigned char *s = src;
+
+	if (d <= s || d - s >= n)
+		return ____memcpy(dest, src, n);
+
+	while (n-- > 0)
+		d[n] = s[n];
+
+	return dest;
+}
+
+/* Detect and warn about potential overlaps, but handle them with memmove. */
+void *memcpy(void *dest, const void *src, size_t n)
+{
+	if (dest > src && dest - src < n) {
+		warn("Avoiding potentially unsafe overlapping memcpy()!");
+		return memmove(dest, src, n);
+	}
+	return ____memcpy(dest, src, n);
+}
+
+#ifdef CONFIG_KASAN
+extern void *__memset(void *s, int c, size_t n) __alias(memset);
+extern void *__memmove(void *dest, const void *src, size_t n) __alias(memmove);
+extern void *__memcpy(void *dest, const void *src, size_t n) __alias(memcpy);
+#endif

linux-7.2.3/arch/x86/boot/compressed/tdcall.S

@@ -0,0 +1,3 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include "../../coco/tdx/tdcall.S"

linux-7.2.3/arch/x86/boot/compressed/tdx-shared.c

@@ -0,0 +1,2 @@
+#include "error.h"
+#include "../../coco/tdx/tdx-shared.c"

linux-7.2.3/arch/x86/boot/compressed/tdx.c

@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "../cpuflags.h"
+#include "../string.h"
+#include "../io.h"
+#include "error.h"
+
+#include <vdso/limits.h>
+#include <uapi/asm/vmx.h>
+
+#include <asm/shared/tdx.h>
+
+/* Called from __tdx_hypercall() for unrecoverable failure */
+void __tdx_hypercall_failed(void)
+{
+	error("TDVMCALL failed. TDX module bug?");
+}
+
+static inline unsigned int tdx_io_in(int size, u16 port)
+{
+	struct tdx_module_args args = {
+		.r10 = TDX_HYPERCALL_STANDARD,
+		.r11 = hcall_func(EXIT_REASON_IO_INSTRUCTION),
+		.r12 = size,
+		.r13 = 0,
+		.r14 = port,
+	};
+
+	if (__tdx_hypercall(&args))
+		return UINT_MAX;
+
+	return args.r11;
+}
+
+static inline void tdx_io_out(int size, u16 port, u32 value)
+{
+	struct tdx_module_args args = {
+		.r10 = TDX_HYPERCALL_STANDARD,
+		.r11 = hcall_func(EXIT_REASON_IO_INSTRUCTION),
+		.r12 = size,
+		.r13 = 1,
+		.r14 = port,
+		.r15 = value,
+	};
+
+	__tdx_hypercall(&args);
+}
+
+static inline u8 tdx_inb(u16 port)
+{
+	return tdx_io_in(1, port);
+}
+
+static inline void tdx_outb(u8 value, u16 port)
+{
+	tdx_io_out(1, port, value);
+}
+
+static inline void tdx_outw(u16 value, u16 port)
+{
+	tdx_io_out(2, port, value);
+}
+
+void early_tdx_detect(void)
+{
+	u32 eax, sig[3];
+
+	cpuid_count(TDX_CPUID_LEAF_ID, 0, &eax, &sig[0], &sig[2],  &sig[1]);
+
+	if (memcmp(TDX_IDENT, sig, sizeof(sig)))
+		return;
+
+	/* Use hypercalls instead of I/O instructions */
+	pio_ops.f_inb  = tdx_inb;
+	pio_ops.f_outb = tdx_outb;
+	pio_ops.f_outw = tdx_outw;
+}

linux-7.2.3/arch/x86/boot/compressed/tdx.h

@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BOOT_COMPRESSED_TDX_H
+#define BOOT_COMPRESSED_TDX_H
+
+#include <linux/types.h>
+
+#ifdef CONFIG_INTEL_TDX_GUEST
+void early_tdx_detect(void);
+#else
+static inline void early_tdx_detect(void) { };
+#endif
+
+#endif /* BOOT_COMPRESSED_TDX_H */

linux-7.2.3/arch/x86/boot/compressed/vmlinux.lds.S

@@ -0,0 +1,128 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <asm-generic/vmlinux.lds.h>
+
+OUTPUT_FORMAT(CONFIG_OUTPUT_FORMAT)
+
+#undef i386
+
+#include <asm/cache.h>
+#include <asm/page_types.h>
+
+#ifdef CONFIG_X86_64
+OUTPUT_ARCH(i386:x86-64)
+ENTRY(startup_64)
+#else
+OUTPUT_ARCH(i386)
+ENTRY(startup_32)
+#endif
+
+SECTIONS
+{
+	/* Be careful parts of head_64.S assume startup_32 is at
+	 * address 0.
+	 */
+	. = 0;
+	.head.text : {
+		_head = . ;
+		HEAD_TEXT
+		_ehead = . ;
+	}
+	.rodata..compressed : {
+		*(.rodata..compressed)
+	}
+	.text :	{
+		_text = .; 	/* Text */
+		*(.text)
+		*(.text.*)
+		*(.noinstr.text)
+		_etext = . ;
+	}
+	.rodata : {
+		_rodata = . ;
+		*(.rodata)	 /* read-only data */
+		*(.rodata.*)
+		_erodata = . ;
+	}
+#ifdef CONFIG_EFI_SBAT
+	.sbat : ALIGN(0x1000) {
+		_sbat = . ;
+		*(.sbat)
+		_esbat = ALIGN(0x1000);
+		. = _esbat;
+	}
+#endif
+	.data :	ALIGN(0x1000) {
+		_data = . ;
+		*(.data)
+		*(.data.*)
+
+		/* Add 4 bytes of extra space for the obsolete CRC-32 checksum */
+		. = ALIGN(. + 4, 0x200);
+		_edata = . ;
+	}
+	. = ALIGN(L1_CACHE_BYTES);
+	.bss : {
+		_bss = . ;
+		*(.bss)
+		*(.bss.*)
+		*(COMMON)
+		. = ALIGN(8);	/* For convenience during zeroing */
+		_ebss = .;
+	}
+#ifdef CONFIG_X86_64
+       . = ALIGN(PAGE_SIZE);
+       .pgtable : {
+		_pgtable = . ;
+		*(.pgtable)
+		_epgtable = . ;
+	}
+#endif
+	. = ALIGN(PAGE_SIZE);	/* keep ZO size page aligned */
+	_end = .;
+
+	STABS_DEBUG
+	DWARF_DEBUG
+	ELF_DETAILS
+
+	DISCARDS
+	/DISCARD/ : {
+		*(.dynamic) *(.dynsym) *(.dynstr) *(.dynbss)
+		*(.hash) *(.gnu.hash)
+		*(.note.*) *(.modinfo)
+	}
+
+	.got.plt (INFO) : {
+		*(.got.plt)
+	}
+	ASSERT(SIZEOF(.got.plt) == 0 ||
+#ifdef CONFIG_X86_64
+	       SIZEOF(.got.plt) == 0x18,
+#else
+	       SIZEOF(.got.plt) == 0xc,
+#endif
+	       "Unexpected GOT/PLT entries detected!")
+
+	/*
+	 * Sections that should stay zero sized, which is safer to
+	 * explicitly check instead of blindly discarding.
+	 */
+	.got : {
+		*(.got)
+	}
+	ASSERT(SIZEOF(.got) == 0, "Unexpected GOT entries detected!")
+
+	.plt : {
+		*(.plt) *(.plt.*)
+	}
+	ASSERT(SIZEOF(.plt) == 0, "Unexpected run-time procedure linkages detected!")
+
+	.rel.dyn : {
+		*(.rel.*) *(.rel_*)
+	}
+	ASSERT(SIZEOF(.rel.dyn) == 0, "Unexpected run-time relocations (.rel) detected!")
+
+	.rela.dyn : {
+		*(.rela.*) *(.rela_*)
+	}
+	ASSERT(SIZEOF(.rela.dyn) == 0, "Unexpected run-time relocations (.rela) detected!")
+}

linux-7.2.3/arch/x86/boot/copy.S

@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* ----------------------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *
+ * ----------------------------------------------------------------------- */
+
+#include <linux/linkage.h>
+
+/*
+ * Memory copy routines
+ */
+
+	.code16
+	.text
+
+SYM_FUNC_START_NOALIGN(memcpy)
+	pushw	%si
+	pushw	%di
+	movw	%ax, %di
+	movw	%dx, %si
+	pushw	%cx
+	shrw	$2, %cx
+	rep movsl
+	popw	%cx
+	andw	$3, %cx
+	rep movsb
+	popw	%di
+	popw	%si
+	retl
+SYM_FUNC_END(memcpy)
+
+SYM_FUNC_START_NOALIGN(memset)
+	pushw	%di
+	movw	%ax, %di
+	movzbl	%dl, %eax
+	imull	$0x01010101,%eax
+	pushw	%cx
+	shrw	$2, %cx
+	rep stosl
+	popw	%cx
+	andw	$3, %cx
+	rep stosb
+	popw	%di
+	retl
+SYM_FUNC_END(memset)
+
+SYM_FUNC_START_NOALIGN(copy_from_fs)
+	pushw	%ds
+	pushw	%fs
+	popw	%ds
+	calll	memcpy
+	popw	%ds
+	retl
+SYM_FUNC_END(copy_from_fs)
+
+SYM_FUNC_START_NOALIGN(copy_to_fs)
+	pushw	%es
+	pushw	%fs
+	popw	%es
+	calll	memcpy
+	popw	%es
+	retl
+SYM_FUNC_END(copy_to_fs)

linux-7.2.3/arch/x86/boot/cpu.c

@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007-2008 rPath, Inc. - All Rights Reserved
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * arch/x86/boot/cpu.c
+ *
+ * Check for obligatory CPU features and abort if the features are not
+ * present.
+ */
+
+#include "boot.h"
+#include "cpustr.h"
+
+static char *cpu_name(int level)
+{
+	static char buf[6];
+
+	if (level == 64) {
+		return "x86-64";
+	} else {
+		if (level == 15)
+			level = 6;
+		sprintf(buf, "i%d86", level);
+		return buf;
+	}
+}
+
+static void show_cap_strs(u32 *err_flags)
+{
+	int i, j;
+	const unsigned char *msg_strs = (const unsigned char *)x86_cap_strs;
+	for (i = 0; i < NCAPINTS; i++) {
+		u32 e = err_flags[i];
+		for (j = 0; j < 32; j++) {
+			if (msg_strs[0] < i ||
+			    (msg_strs[0] == i && msg_strs[1] < j)) {
+				/* Skip to the next string */
+				msg_strs += 2;
+				while (*msg_strs++)
+					;
+			}
+			if (e & 1) {
+				if (msg_strs[0] == i &&
+				    msg_strs[1] == j &&
+				    msg_strs[2])
+					printf("%s ", msg_strs+2);
+				else
+					printf("%d:%d ", i, j);
+			}
+			e >>= 1;
+		}
+	}
+}
+
+int validate_cpu(void)
+{
+	u32 *err_flags;
+	int cpu_level, req_level;
+
+	check_cpu(&cpu_level, &req_level, &err_flags);
+
+	if (cpu_level < req_level) {
+		printf("This kernel requires an %s CPU, ",
+		       cpu_name(req_level));
+		printf("but only detected an %s CPU.\n",
+		       cpu_name(cpu_level));
+		return -1;
+	}
+
+	if (err_flags) {
+		puts("This kernel requires the following features "
+		     "not present on the CPU:\n");
+		show_cap_strs(err_flags);
+		putchar('\n');
+		return -1;
+	} else if (check_knl_erratum()) {
+		return -1;
+	} else {
+		return 0;
+	}
+}

linux-7.2.3/arch/x86/boot/cpucheck.c

@@ -0,0 +1,228 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Check for obligatory CPU features and abort if the features are not
+ * present.  This code should be compilable as 16-, 32- or 64-bit
+ * code, so be very careful with types and inline assembly.
+ *
+ * This code should not contain any messages; that requires an
+ * additional wrapper.
+ *
+ * As written, this code is not safe for inclusion into the kernel
+ * proper (after FPU initialization, in particular).
+ */
+
+#ifdef _SETUP
+# include "boot.h"
+#endif
+#include <linux/types.h>
+#include <asm/cpufeaturemasks.h>
+#include <asm/intel-family.h>
+#include <asm/processor-flags.h>
+#include <asm/msr-index.h>
+#include <asm/shared/msr.h>
+
+#include "string.h"
+
+static u32 err_flags[NCAPINTS];
+
+static const int req_level = CONFIG_X86_MINIMUM_CPU_FAMILY;
+
+static const u32 req_flags[NCAPINTS] =
+{
+	REQUIRED_MASK0,
+	REQUIRED_MASK1,
+	0, /* REQUIRED_MASK2 not implemented in this file */
+	0, /* REQUIRED_MASK3 not implemented in this file */
+	REQUIRED_MASK4,
+	0, /* REQUIRED_MASK5 not implemented in this file */
+	REQUIRED_MASK6,
+	0, /* REQUIRED_MASK7 not implemented in this file */
+	0, /* REQUIRED_MASK8 not implemented in this file */
+	0, /* REQUIRED_MASK9 not implemented in this file */
+	0, /* REQUIRED_MASK10 not implemented in this file */
+	0, /* REQUIRED_MASK11 not implemented in this file */
+	0, /* REQUIRED_MASK12 not implemented in this file */
+	0, /* REQUIRED_MASK13 not implemented in this file */
+	0, /* REQUIRED_MASK14 not implemented in this file */
+	0, /* REQUIRED_MASK15 not implemented in this file */
+	REQUIRED_MASK16,
+};
+
+#define A32(a, b, c, d) (((d) << 24)+((c) << 16)+((b) << 8)+(a))
+
+static int is_amd(void)
+{
+	return cpu_vendor[0] == A32('A', 'u', 't', 'h') &&
+	       cpu_vendor[1] == A32('e', 'n', 't', 'i') &&
+	       cpu_vendor[2] == A32('c', 'A', 'M', 'D');
+}
+
+static int is_centaur(void)
+{
+	return cpu_vendor[0] == A32('C', 'e', 'n', 't') &&
+	       cpu_vendor[1] == A32('a', 'u', 'r', 'H') &&
+	       cpu_vendor[2] == A32('a', 'u', 'l', 's');
+}
+
+static int is_transmeta(void)
+{
+	return cpu_vendor[0] == A32('G', 'e', 'n', 'u') &&
+	       cpu_vendor[1] == A32('i', 'n', 'e', 'T') &&
+	       cpu_vendor[2] == A32('M', 'x', '8', '6');
+}
+
+static int is_intel(void)
+{
+	return cpu_vendor[0] == A32('G', 'e', 'n', 'u') &&
+	       cpu_vendor[1] == A32('i', 'n', 'e', 'I') &&
+	       cpu_vendor[2] == A32('n', 't', 'e', 'l');
+}
+
+/* Returns a bitmask of which words we have error bits in */
+static int check_cpuflags(void)
+{
+	u32 err;
+	int i;
+
+	err = 0;
+	for (i = 0; i < NCAPINTS; i++) {
+		err_flags[i] = req_flags[i] & ~cpu.flags[i];
+		if (err_flags[i])
+			err |= 1 << i;
+	}
+
+	return err;
+}
+
+/*
+ * Returns -1 on error.
+ *
+ * *cpu_level is set to the current CPU level; *req_level to the required
+ * level.  x86-64 is considered level 64 for this purpose.
+ *
+ * *err_flags_ptr is set to the flags error array if there are flags missing.
+ */
+int check_cpu(int *cpu_level_ptr, int *req_level_ptr, u32 **err_flags_ptr)
+{
+	int err;
+
+	memset(&cpu.flags, 0, sizeof(cpu.flags));
+	cpu.level = 3;
+
+	if (has_eflag(X86_EFLAGS_AC))
+		cpu.level = 4;
+
+	get_cpuflags();
+	err = check_cpuflags();
+
+	if (test_bit(X86_FEATURE_LM, cpu.flags))
+		cpu.level = 64;
+
+	if (err == 0x01 &&
+	    !(err_flags[0] &
+	      ~((1 << X86_FEATURE_XMM)|(1 << X86_FEATURE_XMM2))) &&
+	    is_amd()) {
+		/* If this is an AMD and we're only missing SSE+SSE2, try to
+		   turn them on */
+
+		struct msr m;
+
+		raw_rdmsr(MSR_K7_HWCR, &m);
+		m.l &= ~(1 << 15);
+		raw_wrmsr(MSR_K7_HWCR, &m);
+
+		get_cpuflags();	/* Make sure it really did something */
+		err = check_cpuflags();
+	} else if (err == 0x01 &&
+		   !(err_flags[0] & ~(1 << X86_FEATURE_CX8)) &&
+		   is_centaur() && cpu.model >= 6) {
+		/* If this is a VIA C3, we might have to enable CX8
+		   explicitly */
+
+		struct msr m;
+
+		raw_rdmsr(MSR_VIA_FCR, &m);
+		m.l |= (1 << 1) | (1 << 7);
+		raw_wrmsr(MSR_VIA_FCR, &m);
+
+		set_bit(X86_FEATURE_CX8, cpu.flags);
+		err = check_cpuflags();
+	} else if (err == 0x01 && is_transmeta()) {
+		/* Transmeta might have masked feature bits in word 0 */
+
+		struct msr m, m_tmp;
+		u32 level = 1;
+
+		raw_rdmsr(0x80860004, &m);
+		m_tmp = m;
+		m_tmp.l = ~0;
+		raw_wrmsr(0x80860004, &m_tmp);
+		asm("cpuid"
+		    : "+a" (level), "=d" (cpu.flags[0])
+		    : : "ecx", "ebx");
+		raw_wrmsr(0x80860004, &m);
+
+		err = check_cpuflags();
+	} else if (err == 0x01 &&
+		   !(err_flags[0] & ~(1 << X86_FEATURE_PAE)) &&
+		   is_intel() && cpu.level == 6 &&
+		   (cpu.model == 9 || cpu.model == 13)) {
+		/* PAE is disabled on this Pentium M but can be forced */
+		if (cmdline_find_option_bool("forcepae")) {
+			puts("WARNING: Forcing PAE in CPU flags\n");
+			set_bit(X86_FEATURE_PAE, cpu.flags);
+			err = check_cpuflags();
+		}
+		else {
+			puts("WARNING: PAE disabled. Use parameter 'forcepae' to enable at your own risk!\n");
+		}
+	}
+	if (!err)
+		err = check_knl_erratum();
+
+	if (err_flags_ptr)
+		*err_flags_ptr = err ? err_flags : NULL;
+	if (cpu_level_ptr)
+		*cpu_level_ptr = cpu.level;
+	if (req_level_ptr)
+		*req_level_ptr = req_level;
+
+	return (cpu.level < req_level || err) ? -1 : 0;
+}
+
+int check_knl_erratum(void)
+{
+	/*
+	 * First check for the affected model/family:
+	 */
+	if (!is_intel() ||
+	    cpu.family != 6 ||
+	    cpu.model != 0x57 /*INTEL_XEON_PHI_KNL*/)
+		return 0;
+
+	/*
+	 * This erratum affects the Accessed/Dirty bits, and can
+	 * cause stray bits to be set in !Present PTEs.  We have
+	 * enough bits in our 64-bit PTEs (which we have on real
+	 * 64-bit mode or PAE) to avoid using these troublesome
+	 * bits.  But, we do not have enough space in our 32-bit
+	 * PTEs.  So, refuse to run on 32-bit non-PAE kernels.
+	 */
+	if (IS_ENABLED(CONFIG_X86_64) || IS_ENABLED(CONFIG_X86_PAE))
+		return 0;
+
+	puts("This 32-bit kernel can not run on this Xeon Phi x200\n"
+	     "processor due to a processor erratum.  Use a 64-bit\n"
+	     "kernel, or enable PAE in this 32-bit kernel.\n\n");
+
+	return -1;
+}
+
+

linux-7.2.3/arch/x86/boot/cpuflags.c

@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/types.h>
+#include "bitops.h"
+
+#include <asm/processor-flags.h>
+#include <asm/msr-index.h>
+#include "cpuflags.h"
+
+struct cpu_features cpu;
+u32 cpu_vendor[3];
+
+static bool loaded_flags;
+
+static int has_fpu(void)
+{
+	u16 fcw = -1, fsw = -1;
+	unsigned long cr0;
+
+	asm volatile("mov %%cr0,%0" : "=r" (cr0));
+	if (cr0 & (X86_CR0_EM|X86_CR0_TS)) {
+		cr0 &= ~(X86_CR0_EM|X86_CR0_TS);
+		asm volatile("mov %0,%%cr0" : : "r" (cr0));
+	}
+
+	asm volatile("fninit ; fnstsw %0 ; fnstcw %1"
+		     : "+m" (fsw), "+m" (fcw));
+
+	return fsw == 0 && (fcw & 0x103f) == 0x003f;
+}
+
+#ifdef CONFIG_X86_32
+/*
+ * For building the 16-bit code we want to explicitly specify 32-bit
+ * push/pop operations, rather than just saying 'pushf' or 'popf' and
+ * letting the compiler choose.
+ */
+bool has_eflag(unsigned long mask)
+{
+	unsigned long f0, f1;
+
+	asm volatile("pushfl	\n\t"
+		     "pushfl	\n\t"
+		     "pop %0	\n\t"
+		     "mov %0,%1	\n\t"
+		     "xor %2,%1	\n\t"
+		     "push %1	\n\t"
+		     "popfl	\n\t"
+		     "pushfl	\n\t"
+		     "pop %1	\n\t"
+		     "popfl"
+		     : "=&r" (f0), "=&r" (f1)
+		     : "ri" (mask));
+
+	return !!((f0^f1) & mask);
+}
+#endif
+
+void cpuid_count(u32 id, u32 count, u32 *a, u32 *b, u32 *c, u32 *d)
+{
+	asm volatile("cpuid"
+		     : "=a" (*a), "=b" (*b), "=c" (*c), "=d" (*d)
+		     : "0" (id), "2" (count)
+	);
+}
+
+#define cpuid(id, a, b, c, d) cpuid_count(id, 0, a, b, c, d)
+
+void get_cpuflags(void)
+{
+	u32 max_intel_level, max_amd_level;
+	u32 tfms;
+	u32 ignored;
+
+	if (loaded_flags)
+		return;
+	loaded_flags = true;
+
+	if (has_fpu())
+		set_bit(X86_FEATURE_FPU, cpu.flags);
+
+	if (has_eflag(X86_EFLAGS_ID)) {
+		cpuid(0x0, &max_intel_level, &cpu_vendor[0], &cpu_vendor[2],
+		      &cpu_vendor[1]);
+
+		if (max_intel_level >= 0x00000001 &&
+		    max_intel_level <= 0x0000ffff) {
+			cpuid(0x1, &tfms, &ignored, &cpu.flags[4],
+			      &cpu.flags[0]);
+			cpu.level = (tfms >> 8) & 15;
+			cpu.family = cpu.level;
+			cpu.model = (tfms >> 4) & 15;
+			if (cpu.level >= 6)
+				cpu.model += ((tfms >> 16) & 0xf) << 4;
+		}
+
+		if (max_intel_level >= 0x00000007) {
+			cpuid_count(0x00000007, 0, &ignored, &ignored,
+					&cpu.flags[16], &ignored);
+		}
+
+		cpuid(0x80000000, &max_amd_level, &ignored, &ignored,
+		      &ignored);
+
+		if (max_amd_level >= 0x80000001 &&
+		    max_amd_level <= 0x8000ffff) {
+			cpuid(0x80000001, &ignored, &ignored, &cpu.flags[6],
+			      &cpu.flags[1]);
+		}
+	}
+}

linux-7.2.3/arch/x86/boot/cpuflags.h

@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BOOT_CPUFLAGS_H
+#define BOOT_CPUFLAGS_H
+
+#include <asm/cpufeatures.h>
+#include <asm/processor-flags.h>
+
+struct cpu_features {
+	int level;		/* Family, or 64 for x86-64 */
+	int family;		/* Family, always */
+	int model;
+	u32 flags[NCAPINTS];
+};
+
+extern struct cpu_features cpu;
+extern u32 cpu_vendor[3];
+
+#ifdef CONFIG_X86_32
+bool has_eflag(unsigned long mask);
+#else
+static inline bool has_eflag(unsigned long mask) { return true; }
+#endif
+void get_cpuflags(void);
+void cpuid_count(u32 id, u32 count, u32 *a, u32 *b, u32 *c, u32 *d);
+bool has_cpuflag(int flag);
+
+#endif

linux-7.2.3/arch/x86/boot/ctype.h

@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BOOT_CTYPE_H
+#define BOOT_CTYPE_H
+
+static inline int isdigit(int ch)
+{
+	return (ch >= '0') && (ch <= '9');
+}
+
+static inline int isxdigit(int ch)
+{
+	if (isdigit(ch))
+		return true;
+
+	if ((ch >= 'a') && (ch <= 'f'))
+		return true;
+
+	return (ch >= 'A') && (ch <= 'F');
+}
+
+#endif

linux-7.2.3/arch/x86/boot/early_serial_console.c

@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Serial port routines for use during early boot reporting. This code is
+ * included from both the compressed kernel and the regular kernel.
+ */
+#include "boot.h"
+
+#define DEFAULT_SERIAL_PORT 0x3f8 /* ttyS0 */
+
+#define DLAB		0x80
+
+#define TXR             0       /*  Transmit register (WRITE) */
+#define RXR             0       /*  Receive register  (READ)  */
+#define IER             1       /*  Interrupt Enable          */
+#define IIR             2       /*  Interrupt ID              */
+#define FCR             2       /*  FIFO control              */
+#define LCR             3       /*  Line control              */
+#define MCR             4       /*  Modem control             */
+#define LSR             5       /*  Line Status               */
+#define MSR             6       /*  Modem Status              */
+#define DLL             0       /*  Divisor Latch Low         */
+#define DLH             1       /*  Divisor latch High        */
+
+#define DEFAULT_BAUD 9600
+
+static void early_serial_init(int port, int baud)
+{
+	unsigned char c;
+	unsigned divisor;
+
+	outb(0x3, port + LCR);	/* 8n1 */
+	outb(0, port + IER);	/* no interrupt */
+	outb(0, port + FCR);	/* no fifo */
+	outb(0x3, port + MCR);	/* DTR + RTS */
+
+	divisor	= 115200 / baud;
+	c = inb(port + LCR);
+	outb(c | DLAB, port + LCR);
+	outb(divisor & 0xff, port + DLL);
+	outb((divisor >> 8) & 0xff, port + DLH);
+	outb(c & ~DLAB, port + LCR);
+
+	early_serial_base = port;
+}
+
+static void parse_earlyprintk(void)
+{
+	int baud = DEFAULT_BAUD;
+	char arg[32];
+	int pos = 0;
+	int port = 0;
+
+	if (cmdline_find_option("earlyprintk", arg, sizeof(arg)) > 0) {
+		char *e;
+
+		if (!strncmp(arg, "serial", 6)) {
+			port = DEFAULT_SERIAL_PORT;
+			pos += 6;
+		}
+
+		if (arg[pos] == ',')
+			pos++;
+
+		/*
+		 * make sure we have
+		 *	"serial,0x3f8,115200"
+		 *	"serial,ttyS0,115200"
+		 *	"ttyS0,115200"
+		 */
+		if (pos == 7 && !strncmp(arg + pos, "0x", 2)) {
+			port = simple_strtoull(arg + pos, &e, 16);
+			if (port == 0 || arg + pos == e)
+				port = DEFAULT_SERIAL_PORT;
+			else
+				pos = e - arg;
+		} else if (!strncmp(arg + pos, "ttyS", 4)) {
+			static const int bases[] = { 0x3f8, 0x2f8 };
+			int idx = 0;
+
+			/* += strlen("ttyS"); */
+			pos += 4;
+
+			if (arg[pos++] == '1')
+				idx = 1;
+
+			port = bases[idx];
+		}
+
+		if (arg[pos] == ',')
+			pos++;
+
+		baud = simple_strtoull(arg + pos, &e, 0);
+		if (baud == 0 || arg + pos == e)
+			baud = DEFAULT_BAUD;
+	}
+
+	if (port)
+		early_serial_init(port, baud);
+}
+
+#define BASE_BAUD (1843200/16)
+static unsigned int probe_baud(int port)
+{
+	unsigned char lcr, dll, dlh;
+	unsigned int quot;
+
+	lcr = inb(port + LCR);
+	outb(lcr | DLAB, port + LCR);
+	dll = inb(port + DLL);
+	dlh = inb(port + DLH);
+	outb(lcr, port + LCR);
+	quot = (dlh << 8) | dll;
+
+	return BASE_BAUD / quot;
+}
+
+static void parse_console_uart8250(void)
+{
+	char optstr[64], *options;
+	int baud;
+	int port = 0;
+
+	/*
+	 * console=uart8250,io,0x3f8,115200n8
+	 * need to make sure it is last one console !
+	 */
+	if (cmdline_find_option("console", optstr, sizeof(optstr)) <= 0)
+		return;
+
+	options = optstr;
+
+	if (!strncmp(options, "uart8250,io,", 12))
+		port = simple_strtoull(options + 12, &options, 0);
+	else if (!strncmp(options, "uart,io,", 8))
+		port = simple_strtoull(options + 8, &options, 0);
+	else
+		return;
+
+	if (options && (options[0] == ',')) {
+		baud = simple_strtoull(options + 1, NULL, 0);
+		if (!baud)
+			baud = DEFAULT_BAUD;
+	} else {
+		baud = probe_baud(port);
+	}
+
+	if (port)
+		early_serial_init(port, baud);
+}
+
+void console_init(void)
+{
+	parse_earlyprintk();
+
+	if (!early_serial_base)
+		parse_console_uart8250();
+}

linux-7.2.3/arch/x86/boot/edd.c

@@ -0,0 +1,180 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *   Copyright 2009 Intel Corporation; author H. Peter Anvin
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Get EDD BIOS disk information
+ */
+
+#include "boot.h"
+#include <linux/edd.h>
+#include "string.h"
+
+#if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
+
+/*
+ * Read the MBR (first sector) from a specific device.
+ */
+static int read_mbr(u8 devno, void *buf)
+{
+	struct biosregs ireg, oreg;
+
+	initregs(&ireg);
+	ireg.ax = 0x0201;		/* Legacy Read, one sector */
+	ireg.cx = 0x0001;		/* Sector 0-0-1 */
+	ireg.dl = devno;
+	ireg.bx = (size_t)buf;
+
+	intcall(0x13, &ireg, &oreg);
+
+	return -(oreg.eflags & X86_EFLAGS_CF); /* 0 or -1 */
+}
+
+static u32 read_mbr_sig(u8 devno, struct edd_info *ei, u32 *mbrsig)
+{
+	int sector_size;
+	char *mbrbuf_ptr, *mbrbuf_end;
+	u32 buf_base, mbr_base;
+	extern char _end[];
+	u16 mbr_magic;
+
+	sector_size = ei->params.bytes_per_sector;
+	if (!sector_size)
+		sector_size = 512; /* Best available guess */
+
+	/* Produce a naturally aligned buffer on the heap */
+	buf_base = (ds() << 4) + (u32)&_end;
+	mbr_base = (buf_base+sector_size-1) & ~(sector_size-1);
+	mbrbuf_ptr = _end + (mbr_base-buf_base);
+	mbrbuf_end = mbrbuf_ptr + sector_size;
+
+	/* Make sure we actually have space on the heap... */
+	if (!(boot_params.hdr.loadflags & CAN_USE_HEAP))
+		return -1;
+	if (mbrbuf_end > (char *)(size_t)boot_params.hdr.heap_end_ptr)
+		return -1;
+
+	memset(mbrbuf_ptr, 0, sector_size);
+	if (read_mbr(devno, mbrbuf_ptr))
+		return -1;
+
+	*mbrsig = *(u32 *)&mbrbuf_ptr[EDD_MBR_SIG_OFFSET];
+	mbr_magic = *(u16 *)&mbrbuf_ptr[510];
+
+	/* check for valid MBR magic */
+	return mbr_magic == 0xAA55 ? 0 : -1;
+}
+
+static int get_edd_info(u8 devno, struct edd_info *ei)
+{
+	struct biosregs ireg, oreg;
+
+	memset(ei, 0, sizeof(*ei));
+
+	/* Check Extensions Present */
+
+	initregs(&ireg);
+	ireg.ah = 0x41;
+	ireg.bx = EDDMAGIC1;
+	ireg.dl = devno;
+	intcall(0x13, &ireg, &oreg);
+
+	if (oreg.eflags & X86_EFLAGS_CF)
+		return -1;	/* No extended information */
+
+	if (oreg.bx != EDDMAGIC2)
+		return -1;
+
+	ei->device  = devno;
+	ei->version = oreg.ah;		 /* EDD version number */
+	ei->interface_support = oreg.cx; /* EDD functionality subsets */
+
+	/* Extended Get Device Parameters */
+
+	ei->params.length = sizeof(ei->params);
+	ireg.ah = 0x48;
+	ireg.si = (size_t)&ei->params;
+	intcall(0x13, &ireg, &oreg);
+
+	/* Get legacy CHS parameters */
+
+	/* Ralf Brown recommends setting ES:DI to 0:0 */
+	ireg.ah = 0x08;
+	ireg.es = 0;
+	intcall(0x13, &ireg, &oreg);
+
+	if (!(oreg.eflags & X86_EFLAGS_CF)) {
+		ei->legacy_max_cylinder = oreg.ch + ((oreg.cl & 0xc0) << 2);
+		ei->legacy_max_head = oreg.dh;
+		ei->legacy_sectors_per_track = oreg.cl & 0x3f;
+	}
+
+	return 0;
+}
+
+void query_edd(void)
+{
+	char eddarg[8];
+	int do_mbr = 1;
+#ifdef CONFIG_EDD_OFF
+	int do_edd = 0;
+#else
+	int do_edd = 1;
+#endif
+	int be_quiet;
+	int devno;
+	struct edd_info ei, *edp;
+	u32 *mbrptr;
+
+	if (cmdline_find_option("edd", eddarg, sizeof(eddarg)) > 0) {
+		if (!strcmp(eddarg, "skipmbr") || !strcmp(eddarg, "skip")) {
+			do_edd = 1;
+			do_mbr = 0;
+		}
+		else if (!strcmp(eddarg, "off"))
+			do_edd = 0;
+		else if (!strcmp(eddarg, "on"))
+			do_edd = 1;
+	}
+
+	be_quiet = cmdline_find_option_bool("quiet");
+
+	edp    = boot_params.eddbuf;
+	mbrptr = boot_params.edd_mbr_sig_buffer;
+
+	if (!do_edd)
+		return;
+
+	/* Bugs in OnBoard or AddOnCards Bios may hang the EDD probe,
+	 * so give a hint if this happens.
+	 */
+
+	if (!be_quiet)
+		printf("Probing EDD (edd=off to disable)... ");
+
+	for (devno = 0x80; devno < 0x80+EDD_MBR_SIG_MAX; devno++) {
+		/*
+		 * Scan the BIOS-supported hard disks and query EDD
+		 * information...
+		 */
+		if (!get_edd_info(devno, &ei)
+		    && boot_params.eddbuf_entries < EDDMAXNR) {
+			memcpy(edp, &ei, sizeof(ei));
+			edp++;
+			boot_params.eddbuf_entries++;
+		}
+
+		if (do_mbr && !read_mbr_sig(devno, &ei, mbrptr++))
+			boot_params.edd_mbr_sig_buf_entries = devno-0x80+1;
+	}
+
+	if (!be_quiet)
+		printf("ok\n");
+}
+
+#endif

linux-7.2.3/arch/x86/boot/genimage.sh

@@ -0,0 +1,275 @@
+#!/bin/bash
+#
+# This file is subject to the terms and conditions of the GNU General Public
+# License.  See the file "COPYING" in the main directory of this archive
+# for more details.
+#
+# Copyright (C) 2017 by Changbin Du <changbin.du@intel.com>
+#
+# Adapted from code in arch/x86/boot/Makefile by H. Peter Anvin and others
+#
+# "make fdimage/fdimage144/fdimage288/hdimage/isoimage"
+# script for x86 architecture
+#
+# Arguments:
+#   $1  - fdimage format
+#   $2  - target image file
+#   $3  - kernel bzImage file
+#   $4  - mtools configuration file
+#   $5  - kernel cmdline
+#   $6+ - initrd image file(s)
+#
+# This script requires:
+#   bash
+#   syslinux
+#   genisoimage
+#   mtools (for fdimage* and hdimage)
+#   edk2/OVMF (for hdimage)
+#
+# Otherwise try to stick to POSIX shell commands...
+#
+
+# Use "make V=1" to debug this script
+case "${KBUILD_VERBOSE}" in
+*1*)
+        set -x
+        ;;
+esac
+
+# Exit the top-level shell with an error
+topshell=$$
+trap 'exit 1' USR1
+die() {
+	echo ""        1>&2
+	echo " *** $*" 1>&2
+	echo ""        1>&2
+	kill -USR1 $topshell
+}
+
+# Verify the existence and readability of a file
+verify() {
+	if [ ! -f "$1" -o ! -r "$1" ]; then
+		die "Missing file: $1"
+	fi
+}
+
+diskfmt="$1"
+FIMAGE="$2"
+FBZIMAGE="$3"
+MTOOLSRC="$4"
+KCMDLINE="$5"
+shift 5				# Remaining arguments = initrd files
+
+export MTOOLSRC
+
+# common options for dd
+dd='dd iflag=fullblock'
+
+# Make sure the files actually exist
+verify "$FBZIMAGE"
+
+declare -a FDINITRDS
+irdpfx=' initrd='
+initrdopts_syslinux=''
+initrdopts_efi=''
+for f in "$@"; do
+	if [ -f "$f" -a -r "$f" ]; then
+	    FDINITRDS=("${FDINITRDS[@]}" "$f")
+	    fname="$(basename "$f")"
+	    initrdopts_syslinux="${initrdopts_syslinux}${irdpfx}${fname}"
+	    irdpfx=,
+	    initrdopts_efi="${initrdopts_efi} initrd=${fname}"
+	fi
+done
+
+# Read a $3-byte littleendian unsigned value at offset $2 from file $1
+le() {
+	local n=0
+	local m=1
+	for b in $(od -A n -v -j $2 -N $3 -t u1 "$1"); do
+		n=$((n + b*m))
+		m=$((m * 256))
+	done
+	echo $n
+}
+
+# Get the EFI architecture name such that boot{name}.efi is the default
+# boot file name. Returns false with no output if the file is not an
+# EFI image or otherwise unknown.
+efiarch() {
+	[ -f "$1" ] || return
+	[ $(le "$1" 0 2) -eq 23117 ] || return		# MZ magic
+	peoffs=$(le "$1" 60 4)				# PE header offset
+	[ $peoffs -ge 64 ] || return
+	[ $(le "$1" $peoffs 4) -eq 17744 ] || return	# PE magic
+	case $(le "$1" $((peoffs+4+20)) 2) in		# PE type
+		267)	;;				# PE32
+		523)	;;				# PE32+
+		*) return 1 ;;				# Invalid
+	esac
+	[ $(le "$1" $((peoffs+4+20+68)) 2) -eq 10 ] || return # EFI app
+	case $(le "$1" $((peoffs+4)) 2) in		# Machine type
+		 332)	echo i386	;;
+		 450)	echo arm	;;
+		 512)	echo ia64	;;
+		20530)	echo riscv32	;;
+		20580)	echo riscv64	;;
+		20776)	echo riscv128	;;
+		34404)	echo x64	;;
+		43620)	echo aa64	;;
+	esac
+}
+
+# Get the combined sizes in bytes of the files given, counting sparse
+# files as full length, and padding each file to cluster size
+cluster=16384
+filesizes() {
+	local t=0
+	local s
+	for s in $(ls -lnL "$@" 2>/dev/null | awk '/^-/{ print $5; }'); do
+		t=$((t + ((s+cluster-1)/cluster)*cluster))
+	done
+	echo $t
+}
+
+# Expand directory names which should be in /usr/share into a list
+# of possible alternatives
+sharedirs() {
+	local dir file
+	for dir in /usr/share /usr/lib64 /usr/lib; do
+		for file; do
+			echo "$dir/$file"
+			echo "$dir/${file^^}"
+		done
+	done
+}
+efidirs() {
+	local dir file
+	for dir in /usr/share /boot /usr/lib64 /usr/lib; do
+		for file; do
+			echo "$dir/$file"
+			echo "$dir/${file^^}"
+		done
+	done
+}
+
+findsyslinux() {
+	local f="$(find -L $(sharedirs syslinux isolinux) \
+		    -name "$1" -readable -type f -print -quit 2>/dev/null)"
+	if [ ! -f "$f" ]; then
+		die "Need a $1 file, please install syslinux/isolinux."
+	fi
+	echo "$f"
+	return 0
+}
+
+findovmf() {
+	local arch="$1"
+	shift
+	local -a names=(-false)
+	local name f
+	for name; do
+		names=("${names[@]}" -or -iname "$name")
+	done
+	for f in $(find -L $(efidirs edk2 ovmf) \
+			\( "${names[@]}" \) -readable -type f \
+			-print 2>/dev/null); do
+		if [ "$(efiarch "$f")" = "$arch" ]; then
+			echo "$f"
+			return 0
+		fi
+	done
+	die "Need a $1 file for $arch, please install EDK2/OVMF."
+}
+
+do_mcopy() {
+	if [ ${#FDINITRDS[@]} -gt 0 ]; then
+		mcopy "${FDINITRDS[@]}" "$1"
+	fi
+	if [ -n "$efishell" ]; then
+		mmd "$1"EFI "$1"EFI/Boot
+		mcopy "$efishell" "$1"EFI/Boot/boot${kefiarch}.efi
+	fi
+	if [ -n "$kefiarch" ]; then
+		echo linux "$KCMDLINE$initrdopts_efi" | \
+			mcopy - "$1"startup.nsh
+	fi
+	echo default linux "$KCMDLINE$initrdopts_syslinux" | \
+		mcopy - "$1"syslinux.cfg
+	mcopy "$FBZIMAGE" "$1"linux
+}
+
+genbzdisk() {
+	verify "$MTOOLSRC"
+	mformat -v 'LINUX_BOOT' a:
+	syslinux "$FIMAGE"
+	do_mcopy a:
+}
+
+genfdimage144() {
+	verify "$MTOOLSRC"
+	$dd if=/dev/zero of="$FIMAGE" bs=1024 count=1440 2>/dev/null
+	mformat -v 'LINUX_BOOT' v:
+	syslinux "$FIMAGE"
+	do_mcopy v:
+}
+
+genfdimage288() {
+	verify "$MTOOLSRC"
+	$dd if=/dev/zero of="$FIMAGE" bs=1024 count=2880 2>/dev/null
+	mformat -v 'LINUX_BOOT' w:
+	syslinux "$FIMAGE"
+	do_mcopy w:
+}
+
+genhdimage() {
+	verify "$MTOOLSRC"
+	mbr="$(findsyslinux mbr.bin)"
+	kefiarch="$(efiarch "$FBZIMAGE")"
+	if [ -n "$kefiarch" ]; then
+		# The efishell provides command line handling
+		efishell="$(findovmf $kefiarch shell.efi shell${kefiarch}.efi)"
+		ptype='-T 0xef'	# EFI system partition, no GPT
+	fi
+	sizes=$(filesizes "$FBZIMAGE" "${FDINITRDS[@]}" "$efishell")
+	# Allow 1% + 2 MiB for filesystem and partition table overhead,
+	# syslinux, and config files; this is probably excessive...
+	megs=$(((sizes + sizes/100 + 2*1024*1024 - 1)/(1024*1024)))
+	$dd if=/dev/zero of="$FIMAGE" bs=$((1024*1024)) count=$megs 2>/dev/null
+	mpartition -I -c -s 32 -h 64 $ptype -b 64 -a p:
+	$dd if="$mbr" of="$FIMAGE" bs=440 count=1 conv=notrunc 2>/dev/null
+	mformat -v 'LINUX_BOOT' -s 32 -h 64 -c $((cluster/512)) -t $megs h:
+	syslinux --offset $((64*512)) "$FIMAGE"
+	do_mcopy h:
+}
+
+geniso() {
+	tmp_dir="$(dirname "$FIMAGE")/isoimage"
+	rm -rf "$tmp_dir"
+	mkdir "$tmp_dir"
+	isolinux=$(findsyslinux isolinux.bin)
+	ldlinux=$(findsyslinux  ldlinux.c32)
+	cp "$isolinux" "$ldlinux" "$tmp_dir"
+	cp "$FBZIMAGE" "$tmp_dir"/linux
+	echo default linux "$KCMDLINE" > "$tmp_dir"/isolinux.cfg
+	if [ ${#FDINITRDS[@]} -gt 0 ]; then
+		cp "${FDINITRDS[@]}" "$tmp_dir"/
+	fi
+	genisoimage -J -r -appid 'LINUX_BOOT' -input-charset=utf-8 \
+		    -quiet -o "$FIMAGE" -b isolinux.bin \
+		    -c boot.cat -no-emul-boot -boot-load-size 4 \
+		    -boot-info-table "$tmp_dir"
+	isohybrid "$FIMAGE" 2>/dev/null || true
+	rm -rf "$tmp_dir"
+}
+
+rm -f "$FIMAGE"
+
+case "$diskfmt" in
+	bzdisk)     genbzdisk;;
+	fdimage144) genfdimage144;;
+	fdimage288) genfdimage288;;
+	hdimage)    genhdimage;;
+	isoimage)   geniso;;
+	*)          die "Unknown image format: $diskfmt";;
+esac

linux-7.2.3/arch/x86/boot/header.S

@@ -0,0 +1,619 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *	header.S
+ *
+ *	Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ *	Based on bootsect.S and setup.S
+ *	modified by more people than can be counted
+ *
+ *	Rewritten as a common file by H. Peter Anvin (Apr 2007)
+ *
+ * BIG FAT NOTE: We're in real mode using 64k segments.  Therefore segment
+ * addresses must be multiplied by 16 to obtain their respective linear
+ * addresses. To avoid confusion, linear addresses are written using leading
+ * hex while segment addresses are written as segment:offset.
+ *
+ */
+#include <linux/pe.h>
+#include <asm/segment.h>
+#include <asm/boot.h>
+#include <asm/page_types.h>
+#include <asm/setup.h>
+#include <asm/bootparam.h>
+#include "boot.h"
+#include "voffset.h"
+#include "zoffset.h"
+
+BOOTSEG		= 0x07C0		/* original address of boot-sector */
+SYSSEG		= 0x1000		/* historical load address >> 4 */
+
+#ifndef SVGA_MODE
+#define SVGA_MODE ASK_VGA
+#endif
+
+#ifndef ROOT_RDONLY
+#define ROOT_RDONLY 1
+#endif
+
+	.set	salign, 0x1000
+	.set	falign, 0x200
+
+	.code16
+	.section ".bstext", "ax"
+#ifdef CONFIG_EFI_STUB
+	# "MZ", MS-DOS header
+	.word	IMAGE_DOS_SIGNATURE
+	.org	0x38
+	#
+	# Offset to the PE header.
+	#
+	.long	LINUX_PE_MAGIC
+	.long	pe_header
+pe_header:
+	.long	IMAGE_NT_SIGNATURE
+
+coff_header:
+#ifdef CONFIG_X86_32
+	.set	image_file_add_flags, IMAGE_FILE_32BIT_MACHINE
+	.set	pe_opt_magic, IMAGE_NT_OPTIONAL_HDR32_MAGIC
+	.word	IMAGE_FILE_MACHINE_I386
+#else
+	.set	image_file_add_flags, 0
+	.set	pe_opt_magic, IMAGE_NT_OPTIONAL_HDR64_MAGIC
+	.word	IMAGE_FILE_MACHINE_AMD64
+#endif
+	.word	section_count			# nr_sections
+	.long	0 				# TimeDateStamp
+	.long	0				# PointerToSymbolTable
+	.long	1				# NumberOfSymbols
+	.word	section_table - optional_header	# SizeOfOptionalHeader
+	.word	IMAGE_FILE_EXECUTABLE_IMAGE	| \
+		image_file_add_flags		| \
+		IMAGE_FILE_DEBUG_STRIPPED	| \
+		IMAGE_FILE_LINE_NUMS_STRIPPED	# Characteristics
+
+optional_header:
+	.word	pe_opt_magic
+	.byte	0x02				# MajorLinkerVersion
+	.byte	0x14				# MinorLinkerVersion
+
+	.long	ZO__data			# SizeOfCode
+
+	.long	ZO__end - ZO__data		# SizeOfInitializedData
+	.long	0				# SizeOfUninitializedData
+
+	.long	setup_size + ZO_efi_pe_entry	# AddressOfEntryPoint
+
+	.long	setup_size			# BaseOfCode
+#ifdef CONFIG_X86_32
+	.long	0				# data
+#endif
+
+extra_header_fields:
+#ifdef CONFIG_X86_32
+	.long	0				# ImageBase
+#else
+	.quad	0				# ImageBase
+#endif
+	.long	salign				# SectionAlignment
+	.long	falign				# FileAlignment
+	.word	0				# MajorOperatingSystemVersion
+	.word	0				# MinorOperatingSystemVersion
+	.word	LINUX_EFISTUB_MAJOR_VERSION	# MajorImageVersion
+	.word	LINUX_EFISTUB_MINOR_VERSION	# MinorImageVersion
+	.word	0				# MajorSubsystemVersion
+	.word	0				# MinorSubsystemVersion
+	.long	0				# Win32VersionValue
+
+	.long	setup_size + ZO__end		# SizeOfImage
+
+	.long	salign				# SizeOfHeaders
+	.long	0				# CheckSum
+	.word	IMAGE_SUBSYSTEM_EFI_APPLICATION	# Subsystem (EFI application)
+	.word	IMAGE_DLLCHARACTERISTICS_NX_COMPAT	# DllCharacteristics
+#ifdef CONFIG_X86_32
+	.long	0				# SizeOfStackReserve
+	.long	0				# SizeOfStackCommit
+	.long	0				# SizeOfHeapReserve
+	.long	0				# SizeOfHeapCommit
+#else
+	.quad	0				# SizeOfStackReserve
+	.quad	0				# SizeOfStackCommit
+	.quad	0				# SizeOfHeapReserve
+	.quad	0				# SizeOfHeapCommit
+#endif
+	.long	0				# LoaderFlags
+	.long	(section_table - .) / 8		# NumberOfRvaAndSizes
+
+	.quad	0				# ExportTable
+	.quad	0				# ImportTable
+	.quad	0				# ResourceTable
+	.quad	0				# ExceptionTable
+	.quad	0				# CertificationTable
+	.quad	0				# BaseRelocationTable
+
+	# Section table
+section_table:
+	.ascii	".setup"
+	.byte	0
+	.byte	0
+	.long	pecompat_fstart - salign 	# VirtualSize
+	.long	salign				# VirtualAddress
+	.long	pecompat_fstart - salign	# SizeOfRawData
+	.long	salign				# PointerToRawData
+
+	.long	0, 0, 0
+	.long	IMAGE_SCN_CNT_INITIALIZED_DATA	| \
+		IMAGE_SCN_MEM_READ		| \
+		IMAGE_SCN_MEM_DISCARDABLE	# Characteristics
+
+#ifdef CONFIG_EFI_MIXED
+	.asciz	".compat"
+
+	.long	pecompat_fsize			# VirtualSize
+	.long	pecompat_fstart			# VirtualAddress
+	.long	pecompat_fsize			# SizeOfRawData
+	.long	pecompat_fstart			# PointerToRawData
+
+	.long	0, 0, 0
+	.long	IMAGE_SCN_CNT_INITIALIZED_DATA	| \
+		IMAGE_SCN_MEM_READ		| \
+		IMAGE_SCN_MEM_DISCARDABLE	# Characteristics
+
+	/*
+	 * Put the IA-32 machine type and the associated entry point address in
+	 * the .compat section, so loaders can figure out which other execution
+	 * modes this image supports.
+	 */
+	.pushsection ".pecompat", "a", @progbits
+	.balign	salign
+	.globl	pecompat_fstart
+pecompat_fstart:
+	.byte	0x1				# Version
+	.byte	8				# Size
+	.word	IMAGE_FILE_MACHINE_I386		# PE machine type
+	.long	setup_size + ZO_efi32_pe_entry	# Entrypoint
+	.byte	0x0				# Sentinel
+	.popsection
+#else
+	.set	pecompat_fstart, setup_size
+#endif
+	.ascii	".text\0\0\0"
+	.long	textsize            		# VirtualSize
+	.long	setup_size			# VirtualAddress
+	.long	textsize			# SizeOfRawData
+	.long	setup_size			# PointerToRawData
+	.long	0				# PointerToRelocations
+	.long	0				# PointerToLineNumbers
+	.word	0				# NumberOfRelocations
+	.word	0				# NumberOfLineNumbers
+	.long	IMAGE_SCN_CNT_CODE		| \
+		IMAGE_SCN_MEM_READ		| \
+		IMAGE_SCN_MEM_EXECUTE		# Characteristics
+
+#ifdef CONFIG_EFI_SBAT
+	.ascii	".sbat\0\0\0"
+	.long	ZO__esbat - ZO__sbat            # VirtualSize
+	.long	setup_size + ZO__sbat           # VirtualAddress
+	.long	ZO__esbat - ZO__sbat            # SizeOfRawData
+	.long	setup_size + ZO__sbat           # PointerToRawData
+
+	.long	0, 0, 0
+	.long	IMAGE_SCN_CNT_INITIALIZED_DATA	| \
+		IMAGE_SCN_MEM_READ		| \
+		IMAGE_SCN_MEM_DISCARDABLE	# Characteristics
+
+	.set	textsize, ZO__sbat
+#else
+	.set	textsize, ZO__data
+#endif
+
+	.ascii	".data\0\0\0"
+	.long	ZO__end - ZO__data		# VirtualSize
+	.long	setup_size + ZO__data		# VirtualAddress
+	.long	ZO__edata - ZO__data		# SizeOfRawData
+	.long	setup_size + ZO__data		# PointerToRawData
+
+	.long	0, 0, 0
+	.long	IMAGE_SCN_CNT_INITIALIZED_DATA	| \
+		IMAGE_SCN_MEM_READ		| \
+		IMAGE_SCN_MEM_WRITE		# Characteristics
+
+	.set	section_count, (. - section_table) / 40
+#endif /* CONFIG_EFI_STUB */
+
+	# Kernel attributes; used by setup.  This is part 1 of the
+	# header, from the old boot sector.
+
+	.section ".header", "a"
+	.globl	sentinel
+sentinel:	.byte 0xff, 0xff        /* Used to detect broken loaders */
+
+	.globl	hdr
+hdr:
+		.byte setup_sects - 1
+root_flags:	.word ROOT_RDONLY
+syssize:	.long ZO__edata / 16
+ram_size:	.word 0			/* Obsolete */
+vid_mode:	.word SVGA_MODE
+root_dev:	.word 0			/* Default to major/minor 0/0 */
+boot_flag:	.word 0xAA55
+
+	# offset 512, entry point
+
+	.globl	_start
+_start:
+		# Explicitly enter this as bytes, or the assembler
+		# tries to generate a 3-byte jump here, which causes
+		# everything else to push off to the wrong offset.
+		.byte	0xeb		# short (2-byte) jump
+		.byte	start_of_setup-1f
+1:
+
+	# Part 2 of the header, from the old setup.S
+
+		.ascii	"HdrS"		# header signature
+		.word	0x020f		# header version number (>= 0x0105)
+					# or else old loadlin-1.5 will fail)
+		.globl realmode_swtch
+realmode_swtch:	.word	0, 0		# default_switch, SETUPSEG
+start_sys_seg:	.word	SYSSEG		# obsolete and meaningless, but just
+					# in case something decided to "use" it
+		.word	kernel_version-512 # pointing to kernel version string
+					# above section of header is compatible
+					# with loadlin-1.5 (header v1.5). Don't
+					# change it.
+
+type_of_loader:	.byte	0		# 0 means ancient bootloader, newer
+					# bootloaders know to change this.
+					# See Documentation/arch/x86/boot.rst for
+					# assigned ids
+
+# flags, unused bits must be zero (RFU) bit within loadflags
+loadflags:
+		.byte	LOADED_HIGH	# The kernel is to be loaded high
+
+setup_move_size: .word  0x8000		# size to move, when setup is not
+					# loaded at 0x90000. We will move setup
+					# to 0x90000 then just before jumping
+					# into the kernel. However, only the
+					# loader knows how much data behind
+					# us also needs to be loaded.
+
+code32_start:				# here loaders can put a different
+					# start address for 32-bit code.
+		.long	0x100000	# 0x100000 = default for big kernel
+
+ramdisk_image:	.long	0		# address of loaded ramdisk image
+					# Here the loader puts the 32-bit
+					# address where it loaded the image.
+					# This only will be read by the kernel.
+
+ramdisk_size:	.long	0		# its size in bytes
+
+bootsect_kludge:
+		.long	0		# obsolete
+
+heap_end_ptr:	.word	_end+STACK_SIZE-512
+					# (Header version 0x0201 or later)
+					# space from here (exclusive) down to
+					# end of setup code can be used by setup
+					# for local heap purposes.
+
+ext_loader_ver:
+		.byte	0		# Extended boot loader version
+ext_loader_type:
+		.byte	0		# Extended boot loader type
+
+cmd_line_ptr:	.long	0		# (Header version 0x0202 or later)
+					# If nonzero, a 32-bit pointer
+					# to the kernel command line.
+					# The command line should be
+					# located between the start of
+					# setup and the end of low
+					# memory (0xa0000), or it may
+					# get overwritten before it
+					# gets read.  If this field is
+					# used, there is no longer
+					# anything magical about the
+					# 0x90000 segment; the setup
+					# can be located anywhere in
+					# low memory 0x10000 or higher.
+
+initrd_addr_max: .long 0x7fffffff
+					# (Header version 0x0203 or later)
+					# The highest safe address for
+					# the contents of an initrd
+					# The current kernel allows up to 4 GB,
+					# but leave it at 2 GB to avoid
+					# possible bootloader bugs.
+
+kernel_alignment:  .long CONFIG_PHYSICAL_ALIGN	#physical addr alignment
+						#required for protected mode
+						#kernel
+#ifdef CONFIG_RELOCATABLE
+relocatable_kernel:    .byte 1
+#else
+relocatable_kernel:    .byte 0
+#endif
+min_alignment:		.byte MIN_KERNEL_ALIGN_LG2	# minimum alignment
+
+xloadflags:
+#ifdef CONFIG_X86_64
+# define XLF0 XLF_KERNEL_64			/* 64-bit kernel */
+#else
+# define XLF0 0
+#endif
+
+#if defined(CONFIG_RELOCATABLE) && defined(CONFIG_X86_64)
+   /* kernel/boot_param/ramdisk could be loaded above 4g */
+# define XLF1 XLF_CAN_BE_LOADED_ABOVE_4G
+#else
+# define XLF1 0
+#endif
+
+#ifdef CONFIG_EFI_HANDOVER_PROTOCOL
+# ifdef CONFIG_EFI_MIXED
+#  define XLF23 (XLF_EFI_HANDOVER_32|XLF_EFI_HANDOVER_64)
+# else
+#  ifdef CONFIG_X86_64
+#   define XLF23 XLF_EFI_HANDOVER_64		/* 64-bit EFI handover ok */
+#  else
+#   define XLF23 XLF_EFI_HANDOVER_32		/* 32-bit EFI handover ok */
+#  endif
+# endif
+#else
+# define XLF23 0
+#endif
+
+#if defined(CONFIG_X86_64) && defined(CONFIG_EFI) && defined(CONFIG_KEXEC_CORE)
+# define XLF4 XLF_EFI_KEXEC
+#else
+# define XLF4 0
+#endif
+
+#ifdef CONFIG_X86_64
+#define XLF56 (XLF_5LEVEL|XLF_5LEVEL_ENABLED)
+#else
+#define XLF56 0
+#endif
+
+			.word XLF0 | XLF1 | XLF23 | XLF4 | XLF56
+
+cmdline_size:   .long   COMMAND_LINE_SIZE-1     #length of the command line,
+                                                #added with boot protocol
+                                                #version 2.06
+
+hardware_subarch:	.long 0			# subarchitecture, added with 2.07
+						# default to 0 for normal x86 PC
+
+hardware_subarch_data:	.quad 0
+
+payload_offset:		.long ZO_input_data
+payload_length:		.long ZO_z_input_len
+
+setup_data:		.quad 0			# 64-bit physical pointer to
+						# single linked list of
+						# struct setup_data
+
+pref_address:		.quad LOAD_PHYSICAL_ADDR	# preferred load addr
+
+#
+# Getting to provably safe in-place decompression is hard. Worst case
+# behaviours need to be analyzed. Here let's take the decompression of
+# a gzip-compressed kernel as example, to illustrate it:
+#
+# The file layout of gzip compressed kernel is:
+#
+#    magic[2]
+#    method[1]
+#    flags[1]
+#    timestamp[4]
+#    extraflags[1]
+#    os[1]
+#    compressed data blocks[N]
+#    crc[4] orig_len[4]
+#
+# ... resulting in +18 bytes overhead of uncompressed data.
+#
+# (For more information, please refer to RFC 1951 and RFC 1952.)
+#
+# Files divided into blocks
+# 1 bit (last block flag)
+# 2 bits (block type)
+#
+# 1 block occurs every 32K -1 bytes or when there 50% compression
+# has been achieved. The smallest block type encoding is always used.
+#
+# stored:
+#    32 bits length in bytes.
+#
+# fixed:
+#    magic fixed tree.
+#    symbols.
+#
+# dynamic:
+#    dynamic tree encoding.
+#    symbols.
+#
+#
+# The buffer for decompression in place is the length of the uncompressed
+# data, plus a small amount extra to keep the algorithm safe. The
+# compressed data is placed at the end of the buffer.  The output pointer
+# is placed at the start of the buffer and the input pointer is placed
+# where the compressed data starts. Problems will occur when the output
+# pointer overruns the input pointer.
+#
+# The output pointer can only overrun the input pointer if the input
+# pointer is moving faster than the output pointer.  A condition only
+# triggered by data whose compressed form is larger than the uncompressed
+# form.
+#
+# The worst case at the block level is a growth of the compressed data
+# of 5 bytes per 32767 bytes.
+#
+# The worst case internal to a compressed block is very hard to figure.
+# The worst case can at least be bounded by having one bit that represents
+# 32764 bytes and then all of the rest of the bytes representing the very
+# very last byte.
+#
+# All of which is enough to compute an amount of extra data that is required
+# to be safe.  To avoid problems at the block level allocating 5 extra bytes
+# per 32767 bytes of data is sufficient.  To avoid problems internal to a
+# block adding an extra 32767 bytes (the worst case uncompressed block size)
+# is sufficient, to ensure that in the worst case the decompressed data for
+# block will stop the byte before the compressed data for a block begins.
+# To avoid problems with the compressed data's meta information an extra 18
+# bytes are needed.  Leading to the formula:
+#
+# extra_bytes = (uncompressed_size >> 12) + 32768 + 18
+#
+# Adding 8 bytes per 32K is a bit excessive but much easier to calculate.
+# Adding 32768 instead of 32767 just makes for round numbers.
+#
+# Above analysis is for decompressing gzip compressed kernel only. Up to
+# now 6 different decompressor are supported all together. And among them
+# xz stores data in chunks and has maximum chunk of 64K. Hence safety
+# margin should be updated to cover all decompressors so that we don't
+# need to deal with each of them separately. Please check
+# the description in lib/decompressor_xxx.c for specific information.
+#
+# extra_bytes = (uncompressed_size >> 12) + 65536 + 128
+#
+# LZ4 is even worse: data that cannot be further compressed grows by 0.4%,
+# or one byte per 256 bytes. OTOH, we can safely get rid of the +128 as
+# the size-dependent part now grows so fast.
+#
+# extra_bytes = (uncompressed_size >> 8) + 65536
+#
+# ZSTD compressed data grows by at most 3 bytes per 128K, and only has a 22
+# byte fixed overhead but has a maximum block size of 128K, so it needs a
+# larger margin.
+#
+# extra_bytes = (uncompressed_size >> 8) + 131072
+
+#define ZO_z_extra_bytes	((ZO_z_output_len >> 8) + 131072)
+#if ZO_z_output_len > ZO_z_input_len
+# define ZO_z_extract_offset	(ZO_z_output_len + ZO_z_extra_bytes - \
+				 ZO_z_input_len)
+#else
+# define ZO_z_extract_offset	ZO_z_extra_bytes
+#endif
+
+/*
+ * The extract_offset has to be bigger than ZO head section. Otherwise when
+ * the head code is running to move ZO to the end of the buffer, it will
+ * overwrite the head code itself.
+ */
+#if (ZO__ehead - ZO_startup_32) > ZO_z_extract_offset
+# define ZO_z_min_extract_offset ((ZO__ehead - ZO_startup_32 + 4095) & ~4095)
+#else
+# define ZO_z_min_extract_offset ((ZO_z_extract_offset + 4095) & ~4095)
+#endif
+
+#define ZO_INIT_SIZE	(ZO__end - ZO_startup_32 + ZO_z_min_extract_offset)
+
+#define VO_INIT_SIZE	(VO__end - VO__text)
+#if ZO_INIT_SIZE > VO_INIT_SIZE
+# define INIT_SIZE ZO_INIT_SIZE
+#else
+# define INIT_SIZE VO_INIT_SIZE
+#endif
+
+	.macro		__handover_offset
+#ifndef CONFIG_EFI_HANDOVER_PROTOCOL
+	.long		0
+#elif !defined(CONFIG_X86_64)
+	.long		ZO_efi32_stub_entry
+#else
+	/* Yes, this is really how we defined it :( */
+	.long		ZO_efi64_stub_entry - 0x200
+#ifdef CONFIG_EFI_MIXED
+	.if		ZO_efi32_stub_entry != ZO_efi64_stub_entry - 0x200
+	.error		"32-bit and 64-bit EFI entry points do not match"
+	.endif
+#endif
+#endif
+	.endm
+
+init_size:		.long INIT_SIZE		# kernel initialization size
+handover_offset:	__handover_offset
+kernel_info_offset:	.long ZO_kernel_info
+
+# End of setup header #####################################################
+
+	.section ".entrytext", "ax"
+start_of_setup:
+# Force %es = %ds
+	movw	%ds, %ax
+	movw	%ax, %es
+	cld
+
+# Apparently some ancient versions of LILO invoked the kernel with %ss != %ds,
+# which happened to work by accident for the old code.  Recalculate the stack
+# pointer if %ss is invalid.  Otherwise leave it alone, LOADLIN sets up the
+# stack behind its own code, so we can't blindly put it directly past the heap.
+
+	movw	%ss, %dx
+	cmpw	%ax, %dx	# %ds == %ss?
+	movw	%sp, %dx
+	je	2f		# -> assume %sp is reasonably set
+
+	# Invalid %ss, make up a new stack
+	movw	$_end, %dx
+	testb	$CAN_USE_HEAP, loadflags
+	jz	1f
+	movw	heap_end_ptr, %dx
+1:	addw	$STACK_SIZE, %dx
+	jnc	2f
+	xorw	%dx, %dx	# Prevent wraparound
+
+2:	# Now %dx should point to the end of our stack space
+	andw	$~3, %dx	# dword align (might as well...)
+	jnz	3f
+	movw	$0xfffc, %dx	# Make sure we're not zero
+3:	movw	%ax, %ss
+	movzwl	%dx, %esp	# Clear upper half of %esp
+	sti			# Now we should have a working stack
+
+# We will have entered with %cs = %ds+0x20, normalize %cs so
+# it is on par with the other segments.
+	pushw	%ds
+	pushw	$6f
+	lretw
+6:
+
+# Check signature at end of setup
+	cmpl	$0x5a5aaa55, setup_sig
+	jne	setup_bad
+
+# Zero the bss
+	movw	$__bss_start, %di
+	movw	$_end+3, %cx
+	xorl	%eax, %eax
+	subw	%di, %cx
+	shrw	$2, %cx
+	rep stosl
+
+# Jump to C code (should not return)
+	calll	main
+
+# Setup corrupt somehow...
+setup_bad:
+	movl	$setup_corrupt, %eax
+	calll	puts
+	# Fall through...
+
+	.globl	die
+	.type	die, @function
+die:
+	hlt
+	jmp	die
+
+	.size	die, .-die
+
+	.section ".initdata", "a"
+setup_corrupt:
+	.byte	7
+	.string	"No setup signature found...\n"

linux-7.2.3/arch/x86/boot/install.sh

@@ -0,0 +1,39 @@
+#!/bin/sh
+#
+# This file is subject to the terms and conditions of the GNU General Public
+# License.  See the file "COPYING" in the main directory of this archive
+# for more details.
+#
+# Copyright (C) 1995 by Linus Torvalds
+#
+# Adapted from code in arch/i386/boot/Makefile by H. Peter Anvin
+#
+# "make install" script for i386 architecture
+#
+# Arguments:
+#   $1 - kernel version
+#   $2 - kernel image file
+#   $3 - kernel map file
+#   $4 - default install path (blank if root directory)
+
+set -e
+
+if [ -f $4/vmlinuz ]; then
+	mv $4/vmlinuz $4/vmlinuz.old
+fi
+
+if [ -f $4/System.map ]; then
+	mv $4/System.map $4/System.old
+fi
+
+cat $2 > $4/vmlinuz
+cp $3 $4/System.map
+
+if [ -x /sbin/lilo ]; then
+       /sbin/lilo
+elif [ -x /etc/lilo/install ]; then
+       /etc/lilo/install
+else
+       sync
+       echo "Cannot find LILO."
+fi

linux-7.2.3/arch/x86/boot/io.h

@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BOOT_IO_H
+#define BOOT_IO_H
+
+#include <asm/shared/io.h>
+
+#undef inb
+#undef inw
+#undef inl
+#undef outb
+#undef outw
+#undef outl
+
+struct port_io_ops {
+	u8	(*f_inb)(u16 port);
+	void	(*f_outb)(u8 v, u16 port);
+	void	(*f_outw)(u16 v, u16 port);
+};
+
+extern struct port_io_ops pio_ops;
+
+/*
+ * Use the normal I/O instructions by default.
+ * TDX guests override these to use hypercalls.
+ */
+static inline void init_default_io_ops(void)
+{
+	pio_ops.f_inb  = __inb;
+	pio_ops.f_outb = __outb;
+	pio_ops.f_outw = __outw;
+}
+
+/*
+ * Redirect port I/O operations via pio_ops callbacks.
+ * TDX guests override these callbacks with TDX-specific helpers.
+ */
+#define inb  pio_ops.f_inb
+#define outb pio_ops.f_outb
+#define outw pio_ops.f_outw
+
+#endif

linux-7.2.3/arch/x86/boot/main.c

@@ -0,0 +1,181 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *   Copyright 2009 Intel Corporation; author H. Peter Anvin
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Main module for the real-mode kernel code
+ */
+#include <linux/build_bug.h>
+
+#include "boot.h"
+#include "string.h"
+
+struct boot_params boot_params __attribute__((aligned(16)));
+
+struct port_io_ops pio_ops;
+
+char *HEAP = _end;
+char *heap_end = _end;		/* Default end of heap = no heap */
+
+/*
+ * Copy the header into the boot parameter block.  Since this
+ * screws up the old-style command line protocol, adjust by
+ * filling in the new-style command line pointer instead.
+ */
+static void copy_boot_params(void)
+{
+	struct old_cmdline {
+		u16 cl_magic;
+		u16 cl_offset;
+	};
+	const struct old_cmdline * const oldcmd = absolute_pointer(OLD_CL_ADDRESS);
+
+	BUILD_BUG_ON(sizeof(boot_params) != 4096);
+	memcpy(&boot_params.hdr, &hdr, sizeof(hdr));
+
+	if (!boot_params.hdr.cmd_line_ptr && oldcmd->cl_magic == OLD_CL_MAGIC) {
+		/* Old-style command line protocol */
+		u16 cmdline_seg;
+
+		/*
+		 * Figure out if the command line falls in the region
+		 * of memory that an old kernel would have copied up
+		 * to 0x90000...
+		 */
+		if (oldcmd->cl_offset < boot_params.hdr.setup_move_size)
+			cmdline_seg = ds();
+		else
+			cmdline_seg = 0x9000;
+
+		boot_params.hdr.cmd_line_ptr = (cmdline_seg << 4) + oldcmd->cl_offset;
+	}
+}
+
+/*
+ * Query the keyboard lock status as given by the BIOS, and
+ * set the keyboard repeat rate to maximum.  Unclear why the latter
+ * is done here; this might be possible to kill off as stale code.
+ */
+static void keyboard_init(void)
+{
+	struct biosregs ireg, oreg;
+
+	initregs(&ireg);
+
+	ireg.ah = 0x02;		/* Get keyboard status */
+	intcall(0x16, &ireg, &oreg);
+	boot_params.kbd_status = oreg.al;
+
+	ireg.ax = 0x0305;	/* Set keyboard repeat rate */
+	intcall(0x16, &ireg, NULL);
+}
+
+/*
+ * Get Intel SpeedStep (IST) information.
+ */
+static void query_ist(void)
+{
+	struct biosregs ireg, oreg;
+
+	/*
+	 * Some older BIOSes apparently crash on this call, so filter
+	 * it from machines too old to have SpeedStep at all.
+	 */
+	if (cpu.level < 6)
+		return;
+
+	initregs(&ireg);
+	ireg.ax  = 0xe980;	 /* IST Support */
+	ireg.edx = 0x47534943;	 /* Request value */
+	intcall(0x15, &ireg, &oreg);
+
+	boot_params.ist_info.signature  = oreg.eax;
+	boot_params.ist_info.command    = oreg.ebx;
+	boot_params.ist_info.event      = oreg.ecx;
+	boot_params.ist_info.perf_level = oreg.edx;
+}
+
+/*
+ * Tell the BIOS what CPU mode we intend to run in.
+ */
+static void set_bios_mode(void)
+{
+#ifdef CONFIG_X86_64
+	struct biosregs ireg;
+
+	initregs(&ireg);
+	ireg.ax = 0xec00;
+	ireg.bx = 2;
+	intcall(0x15, &ireg, NULL);
+#endif
+}
+
+static void init_heap(void)
+{
+	char *stack_end;
+
+	if (boot_params.hdr.loadflags & CAN_USE_HEAP) {
+		stack_end = (char *) (current_stack_pointer - STACK_SIZE);
+		heap_end = (char *) ((size_t)boot_params.hdr.heap_end_ptr + 0x200);
+		if (heap_end > stack_end)
+			heap_end = stack_end;
+	} else {
+		/* Boot protocol 2.00 only, no heap available */
+		puts("WARNING: Ancient bootloader, some functionality may be limited!\n");
+	}
+}
+
+void main(void)
+{
+	init_default_io_ops();
+
+	/* First, copy the boot header into the "zeropage" */
+	copy_boot_params();
+
+	/* Initialize the early-boot console */
+	console_init();
+	if (cmdline_find_option_bool("debug"))
+		puts("early console in setup code\n");
+
+	/* End of heap check */
+	init_heap();
+
+	/* Make sure we have all the proper CPU support */
+	if (validate_cpu()) {
+		puts("Unable to boot - please use a kernel appropriate for your CPU.\n");
+		die();
+	}
+
+	/* Tell the BIOS what CPU mode we intend to run in */
+	set_bios_mode();
+
+	/* Detect memory layout */
+	detect_memory();
+
+	/* Set keyboard repeat rate (why?) and query the lock flags */
+	keyboard_init();
+
+	/* Query Intel SpeedStep (IST) information */
+	query_ist();
+
+	/* Query APM information */
+#if defined(CONFIG_APM) || defined(CONFIG_APM_MODULE)
+	query_apm_bios();
+#endif
+
+	/* Query EDD information */
+#if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
+	query_edd();
+#endif
+
+	/* Set the video mode */
+	set_video();
+
+	/* Do the last things and invoke protected mode */
+	go_to_protected_mode();
+}

linux-7.2.3/arch/x86/boot/memory.c

@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *   Copyright 2009 Intel Corporation; author H. Peter Anvin
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Memory detection code
+ */
+
+#include "boot.h"
+
+#define SMAP	0x534d4150	/* ASCII "SMAP" */
+
+static void detect_memory_e820(void)
+{
+	int count = 0;
+	struct biosregs ireg, oreg;
+	struct boot_e820_entry *desc = boot_params.e820_table;
+	static struct boot_e820_entry buf; /* static so it is zeroed */
+
+	initregs(&ireg);
+	ireg.ax  = 0xe820;
+	ireg.cx  = sizeof(buf);
+	ireg.edx = SMAP;
+	ireg.di  = (size_t)&buf;
+
+	/*
+	 * Note: at least one BIOS is known which assumes that the
+	 * buffer pointed to by one e820 call is the same one as
+	 * the previous call, and only changes modified fields.  Therefore,
+	 * we use a temporary buffer and copy the results entry by entry.
+	 *
+	 * This routine deliberately does not try to account for
+	 * ACPI 3+ extended attributes.  This is because there are
+	 * BIOSes in the field which report zero for the valid bit for
+	 * all ranges, and we don't currently make any use of the
+	 * other attribute bits.  Revisit this if we see the extended
+	 * attribute bits deployed in a meaningful way in the future.
+	 */
+
+	do {
+		intcall(0x15, &ireg, &oreg);
+		ireg.ebx = oreg.ebx; /* for next iteration... */
+
+		/* BIOSes which terminate the chain with CF = 1 as opposed
+		   to %ebx = 0 don't always report the SMAP signature on
+		   the final, failing, probe. */
+		if (oreg.eflags & X86_EFLAGS_CF)
+			break;
+
+		/* Some BIOSes stop returning SMAP in the middle of
+		   the search loop.  We don't know exactly how the BIOS
+		   screwed up the map at that point, we might have a
+		   partial map, the full map, or complete garbage, so
+		   just return failure. */
+		if (oreg.eax != SMAP) {
+			count = 0;
+			break;
+		}
+
+		*desc++ = buf;
+		count++;
+	} while (ireg.ebx && count < ARRAY_SIZE(boot_params.e820_table));
+
+	boot_params.e820_entries = count;
+}
+
+static void detect_memory_e801(void)
+{
+	struct biosregs ireg, oreg;
+
+	initregs(&ireg);
+	ireg.ax = 0xe801;
+	intcall(0x15, &ireg, &oreg);
+
+	if (oreg.eflags & X86_EFLAGS_CF)
+		return;
+
+	/* Do we really need to do this? */
+	if (oreg.cx || oreg.dx) {
+		oreg.ax = oreg.cx;
+		oreg.bx = oreg.dx;
+	}
+
+	if (oreg.ax > 15*1024) {
+		return;	/* Bogus! */
+	} else if (oreg.ax == 15*1024) {
+		boot_params.alt_mem_k = (oreg.bx << 6) + oreg.ax;
+	} else {
+		/*
+		 * This ignores memory above 16MB if we have a memory
+		 * hole there.  If someone actually finds a machine
+		 * with a memory hole at 16MB and no support for
+		 * 0E820h they should probably generate a fake e820
+		 * map.
+		 */
+		boot_params.alt_mem_k = oreg.ax;
+	}
+}
+
+static void detect_memory_88(void)
+{
+	struct biosregs ireg, oreg;
+
+	initregs(&ireg);
+	ireg.ah = 0x88;
+	intcall(0x15, &ireg, &oreg);
+
+	boot_params.screen_info.ext_mem_k = oreg.ax;
+}
+
+void detect_memory(void)
+{
+	detect_memory_e820();
+
+	detect_memory_e801();
+
+	detect_memory_88();
+}

linux-7.2.3/arch/x86/boot/mkcpustr.c

@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* ----------------------------------------------------------------------- *
+ *
+ *   Copyright 2008 rPath, Inc. - All Rights Reserved
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * This is a host program to preprocess the CPU strings into a
+ * compact format suitable for the setup code.
+ */
+
+#include <stdio.h>
+
+#include "../include/asm/cpufeatures.h"
+#include "../include/asm/vmxfeatures.h"
+#include "../kernel/cpu/capflags.c"
+
+int main(void)
+{
+	int i, j;
+	const char *str;
+
+	printf("#include <asm/cpufeaturemasks.h>\n\n");
+	printf("static const char x86_cap_strs[] =\n");
+
+	for (i = 0; i < NCAPINTS; i++) {
+		for (j = 0; j < 32; j++) {
+			str = x86_cap_flags[i*32+j];
+
+			if (i == NCAPINTS-1 && j == 31) {
+				/* The last entry must be unconditional; this
+				   also consumes the compiler-added null
+				   character */
+				if (!str)
+					str = "";
+				printf("\t\"\\x%02x\\x%02x\"\"%s\"\n",
+				       i, j, str);
+			} else if (str) {
+				printf("#if REQUIRED_MASK%d & (1 << %d)\n"
+				       "\t\"\\x%02x\\x%02x\"\"%s\\0\"\n"
+				       "#endif\n",
+				       i, j, i, j, str);
+			}
+		}
+	}
+	printf("\t;\n");
+	return 0;
+}

linux-7.2.3/arch/x86/boot/mtools.conf.in

@@ -0,0 +1,21 @@
+#
+# mtools configuration file for "make (b)zdisk"
+#
+
+# Actual floppy drive
+drive a:
+  file="/dev/fd0"
+
+# 1.44 MB floppy disk image
+drive v:
+  file="@OBJ@/fdimage" cylinders=80 heads=2 sectors=18 filter
+
+# 2.88 MB floppy disk image (mostly for virtual uses)
+drive w:
+  file="@OBJ@/fdimage" cylinders=80 heads=2 sectors=36 filter
+
+# Hard disk (h: for the filesystem, p: for format - old mtools bug?)
+drive h:
+  file="@OBJ@/hdimage" offset=32768 mformat_only
+drive p:
+  file="@OBJ@/hdimage" partition=1 mformat_only

linux-7.2.3/arch/x86/boot/pm.c

@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Prepare the machine for transition to protected mode.
+ */
+
+#include "boot.h"
+#include <asm/desc_defs.h>
+#include <asm/segment.h>
+
+/*
+ * Invoke the realmode switch hook if present; otherwise
+ * disable all interrupts.
+ */
+static void realmode_switch_hook(void)
+{
+	if (boot_params.hdr.realmode_swtch) {
+		asm volatile("lcallw *%0"
+			     : : "m" (boot_params.hdr.realmode_swtch)
+			     : "eax", "ebx", "ecx", "edx");
+	} else {
+		asm volatile("cli");
+		outb(0x80, 0x70); /* Disable NMI */
+		io_delay();
+	}
+}
+
+/*
+ * Disable all interrupts at the legacy PIC.
+ */
+static void mask_all_interrupts(void)
+{
+	outb(0xff, 0xa1);	/* Mask all interrupts on the secondary PIC */
+	io_delay();
+	outb(0xfb, 0x21);	/* Mask all but cascade on the primary PIC */
+	io_delay();
+}
+
+/*
+ * Reset IGNNE# if asserted in the FPU.
+ */
+static void reset_coprocessor(void)
+{
+	outb(0, 0xf0);
+	io_delay();
+	outb(0, 0xf1);
+	io_delay();
+}
+
+/*
+ * Set up the GDT
+ */
+
+struct gdt_ptr {
+	u16 len;
+	u32 ptr;
+} __attribute__((packed));
+
+static void setup_gdt(void)
+{
+	/* There are machines which are known to not boot with the GDT
+	   being 8-byte unaligned.  Intel recommends 16 byte alignment. */
+	static const u64 boot_gdt[] __attribute__((aligned(16))) = {
+		/* CS: code, read/execute, 4 GB, base 0 */
+		[GDT_ENTRY_BOOT_CS] = GDT_ENTRY(DESC_CODE32, 0, 0xfffff),
+		/* DS: data, read/write, 4 GB, base 0 */
+		[GDT_ENTRY_BOOT_DS] = GDT_ENTRY(DESC_DATA32, 0, 0xfffff),
+		/* TSS: 32-bit tss, 104 bytes, base 4096 */
+		/* We only have a TSS here to keep Intel VT happy;
+		   we don't actually use it for anything. */
+		[GDT_ENTRY_BOOT_TSS] = GDT_ENTRY(DESC_TSS32, 4096, 103),
+	};
+	/* Xen HVM incorrectly stores a pointer to the gdt_ptr, instead
+	   of the gdt_ptr contents.  Thus, make it static so it will
+	   stay in memory, at least long enough that we switch to the
+	   proper kernel GDT. */
+	static struct gdt_ptr gdt;
+
+	gdt.len = sizeof(boot_gdt)-1;
+	gdt.ptr = (u32)&boot_gdt + (ds() << 4);
+
+	asm volatile("lgdtl %0" : : "m" (gdt));
+}
+
+/*
+ * Set up the IDT
+ */
+static void setup_idt(void)
+{
+	static const struct gdt_ptr null_idt = {0, 0};
+	asm volatile("lidtl %0" : : "m" (null_idt));
+}
+
+/*
+ * Actual invocation sequence
+ */
+void go_to_protected_mode(void)
+{
+	/* Hook before leaving real mode, also disables interrupts */
+	realmode_switch_hook();
+
+	/* Enable the A20 gate */
+	if (enable_a20()) {
+		puts("A20 gate not responding, unable to boot...\n");
+		die();
+	}
+
+	/* Reset coprocessor (IGNNE#) */
+	reset_coprocessor();
+
+	/* Mask all interrupts in the PIC */
+	mask_all_interrupts();
+
+	/* Actual transition to protected mode... */
+	setup_idt();
+	setup_gdt();
+	protected_mode_jump(boot_params.hdr.code32_start,
+			    (u32)&boot_params + (ds() << 4));
+}

linux-7.2.3/arch/x86/boot/pmjump.S

@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* ----------------------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * The actual transition into protected mode
+ */
+
+#include <asm/boot.h>
+#include <asm/processor-flags.h>
+#include <asm/segment.h>
+#include <linux/linkage.h>
+
+	.text
+	.code16
+
+/*
+ * void protected_mode_jump(u32 entrypoint, u32 bootparams);
+ */
+SYM_FUNC_START_NOALIGN(protected_mode_jump)
+	movl	%edx, %esi		# Pointer to boot_params table
+
+	xorl	%ebx, %ebx
+	movw	%cs, %bx
+	shll	$4, %ebx
+	addl	%ebx, 2f
+	jmp	1f			# Short jump to serialize on 386/486
+1:
+
+	movw	$__BOOT_DS, %cx
+	movw	$__BOOT_TSS, %di
+
+	movl	%cr0, %edx
+	orb	$X86_CR0_PE, %dl	# Protected mode
+	movl	%edx, %cr0
+
+	# Transition to 32-bit mode
+	.byte	0x66, 0xea		# ljmpl opcode
+2:	.long	.Lin_pm32		# offset
+	.word	__BOOT_CS		# segment
+SYM_FUNC_END(protected_mode_jump)
+
+	.code32
+	.section ".text32","ax"
+SYM_FUNC_START_LOCAL_NOALIGN(.Lin_pm32)
+	# Set up data segments for flat 32-bit mode
+	movl	%ecx, %ds
+	movl	%ecx, %es
+	movl	%ecx, %fs
+	movl	%ecx, %gs
+	movl	%ecx, %ss
+	# The 32-bit code sets up its own stack, but this way we do have
+	# a valid stack if some debugging hack wants to use it.
+	addl	%ebx, %esp
+
+	# Set up TR to make Intel VT happy
+	ltr	%di
+
+	# Clear registers to allow for future extensions to the
+	# 32-bit boot protocol
+	xorl	%ecx, %ecx
+	xorl	%edx, %edx
+	xorl	%ebx, %ebx
+	xorl	%ebp, %ebp
+	xorl	%edi, %edi
+
+	# Set up LDTR to make Intel VT happy
+	lldt	%cx
+
+	jmpl	*%eax			# Jump to the 32-bit entrypoint
+SYM_FUNC_END(.Lin_pm32)

linux-7.2.3/arch/x86/boot/printf.c

@@ -0,0 +1,310 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Oh, it's a waste of space, but oh-so-yummy for debugging.  This
+ * version of printf() does not include 64-bit support.  "Live with
+ * it."
+ *
+ */
+
+#include "boot.h"
+
+static int skip_atoi(const char **s)
+{
+	int i = 0;
+
+	while (isdigit(**s))
+		i = i * 10 + *((*s)++) - '0';
+	return i;
+}
+
+#define ZEROPAD	1		/* pad with zero */
+#define SIGN	2		/* unsigned/signed long */
+#define PLUS	4		/* show plus */
+#define SPACE	8		/* space if plus */
+#define LEFT	16		/* left justified */
+#define SMALL	32		/* Must be 32 == 0x20 */
+#define SPECIAL	64		/* 0x */
+
+#define __do_div(n, base) ({ \
+int __res; \
+__res = ((unsigned long) n) % (unsigned) base; \
+n = ((unsigned long) n) / (unsigned) base; \
+__res; })
+
+static char *number(char *str, long num, int base, int size, int precision,
+		    int type)
+{
+	/* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
+	static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
+
+	char tmp[66];
+	char c, sign, locase;
+	int i;
+
+	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
+	 * produces same digits or (maybe lowercased) letters */
+	locase = (type & SMALL);
+	if (type & LEFT)
+		type &= ~ZEROPAD;
+	if (base < 2 || base > 16)
+		return NULL;
+	c = (type & ZEROPAD) ? '0' : ' ';
+	sign = 0;
+	if (type & SIGN) {
+		if (num < 0) {
+			sign = '-';
+			num = -num;
+			size--;
+		} else if (type & PLUS) {
+			sign = '+';
+			size--;
+		} else if (type & SPACE) {
+			sign = ' ';
+			size--;
+		}
+	}
+	if (type & SPECIAL) {
+		if (base == 16)
+			size -= 2;
+		else if (base == 8)
+			size--;
+	}
+	i = 0;
+	if (num == 0)
+		tmp[i++] = '0';
+	else
+		while (num != 0)
+			tmp[i++] = (digits[__do_div(num, base)] | locase);
+	if (i > precision)
+		precision = i;
+	size -= precision;
+	if (!(type & (ZEROPAD + LEFT)))
+		while (size-- > 0)
+			*str++ = ' ';
+	if (sign)
+		*str++ = sign;
+	if (type & SPECIAL) {
+		if (base == 8)
+			*str++ = '0';
+		else if (base == 16) {
+			*str++ = '0';
+			*str++ = ('X' | locase);
+		}
+	}
+	if (!(type & LEFT))
+		while (size-- > 0)
+			*str++ = c;
+	while (i < precision--)
+		*str++ = '0';
+	while (i-- > 0)
+		*str++ = tmp[i];
+	while (size-- > 0)
+		*str++ = ' ';
+	return str;
+}
+
+int vsprintf(char *buf, const char *fmt, va_list args)
+{
+	int len;
+	unsigned long num;
+	int i, base;
+	char *str;
+	const char *s;
+
+	int flags;		/* flags to number() */
+
+	int field_width;	/* width of output field */
+	int precision;		/* min. # of digits for integers; max
+				   number of chars for from string */
+	int qualifier;		/* 'h', 'l', or 'L' for integer fields */
+
+	for (str = buf; *fmt; ++fmt) {
+		if (*fmt != '%') {
+			*str++ = *fmt;
+			continue;
+		}
+
+		/* process flags */
+		flags = 0;
+	      repeat:
+		++fmt;		/* this also skips first '%' */
+		switch (*fmt) {
+		case '-':
+			flags |= LEFT;
+			goto repeat;
+		case '+':
+			flags |= PLUS;
+			goto repeat;
+		case ' ':
+			flags |= SPACE;
+			goto repeat;
+		case '#':
+			flags |= SPECIAL;
+			goto repeat;
+		case '0':
+			flags |= ZEROPAD;
+			goto repeat;
+		}
+
+		/* get field width */
+		field_width = -1;
+		if (isdigit(*fmt))
+			field_width = skip_atoi(&fmt);
+		else if (*fmt == '*') {
+			++fmt;
+			/* it's the next argument */
+			field_width = va_arg(args, int);
+			if (field_width < 0) {
+				field_width = -field_width;
+				flags |= LEFT;
+			}
+		}
+
+		/* get the precision */
+		precision = -1;
+		if (*fmt == '.') {
+			++fmt;
+			if (isdigit(*fmt))
+				precision = skip_atoi(&fmt);
+			else if (*fmt == '*') {
+				++fmt;
+				/* it's the next argument */
+				precision = va_arg(args, int);
+			}
+			if (precision < 0)
+				precision = 0;
+		}
+
+		/* get the conversion qualifier */
+		qualifier = -1;
+		if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L') {
+			qualifier = *fmt;
+			++fmt;
+		}
+
+		/* default base */
+		base = 10;
+
+		switch (*fmt) {
+		case 'c':
+			if (!(flags & LEFT))
+				while (--field_width > 0)
+					*str++ = ' ';
+			*str++ = (unsigned char)va_arg(args, int);
+			while (--field_width > 0)
+				*str++ = ' ';
+			continue;
+
+		case 's':
+			s = va_arg(args, char *);
+			len = strnlen(s, precision);
+
+			if (!(flags & LEFT))
+				while (len < field_width--)
+					*str++ = ' ';
+			for (i = 0; i < len; ++i)
+				*str++ = *s++;
+			while (len < field_width--)
+				*str++ = ' ';
+			continue;
+
+		case 'p':
+			if (field_width == -1) {
+				field_width = 2 * sizeof(void *);
+				flags |= ZEROPAD;
+			}
+			str = number(str,
+				     (unsigned long)va_arg(args, void *), 16,
+				     field_width, precision, flags);
+			continue;
+
+		case 'n':
+			if (qualifier == 'l') {
+				long *ip = va_arg(args, long *);
+				*ip = (str - buf);
+			} else {
+				int *ip = va_arg(args, int *);
+				*ip = (str - buf);
+			}
+			continue;
+
+		case '%':
+			*str++ = '%';
+			continue;
+
+			/* integer number formats - set up the flags and "break" */
+		case 'o':
+			base = 8;
+			break;
+
+		case 'x':
+			flags |= SMALL;
+			fallthrough;
+		case 'X':
+			base = 16;
+			break;
+
+		case 'd':
+		case 'i':
+			flags |= SIGN;
+			break;
+
+		case 'u':
+			break;
+
+		default:
+			*str++ = '%';
+			if (*fmt)
+				*str++ = *fmt;
+			else
+				--fmt;
+			continue;
+		}
+		if (qualifier == 'l')
+			num = va_arg(args, unsigned long);
+		else if (qualifier == 'h') {
+			num = (unsigned short)va_arg(args, int);
+			if (flags & SIGN)
+				num = (short)num;
+		} else if (flags & SIGN)
+			num = va_arg(args, int);
+		else
+			num = va_arg(args, unsigned int);
+		str = number(str, num, base, field_width, precision, flags);
+	}
+	*str = '\0';
+	return str - buf;
+}
+
+int sprintf(char *buf, const char *fmt, ...)
+{
+	va_list args;
+	int i;
+
+	va_start(args, fmt);
+	i = vsprintf(buf, fmt, args);
+	va_end(args);
+	return i;
+}
+
+int printf(const char *fmt, ...)
+{
+	char printf_buf[1024];
+	va_list args;
+	int printed;
+
+	va_start(args, fmt);
+	printed = vsprintf(printf_buf, fmt, args);
+	va_end(args);
+
+	puts(printf_buf);
+
+	return printed;
+}

linux-7.2.3/arch/x86/boot/regs.c

@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* -----------------------------------------------------------------------
+ *
+ *   Copyright 2009 Intel Corporation; author H. Peter Anvin
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Simple helper function for initializing a register set.
+ *
+ * Note that this sets EFLAGS_CF in the input register set; this
+ * makes it easier to catch functions which do nothing but don't
+ * explicitly set CF.
+ */
+
+#include "boot.h"
+#include "string.h"
+
+void initregs(struct biosregs *reg)
+{
+	memset(reg, 0, sizeof(*reg));
+	reg->eflags |= X86_EFLAGS_CF;
+	reg->ds = ds();
+	reg->es = ds();
+	reg->fs = fs();
+	reg->gs = gs();
+}

linux-7.2.3/arch/x86/boot/setup.ld

@@ -0,0 +1,74 @@
+/*
+ * setup.ld
+ *
+ * Linker script for the i386 setup code
+ */
+OUTPUT_FORMAT("elf32-i386")
+OUTPUT_ARCH(i386)
+ENTRY(_start)
+
+SECTIONS
+{
+	. = 0;
+	.bstext	: {
+		*(.bstext)
+		. = 495;
+	} =0xffffffff
+
+	.header		: { *(.header) }
+	.entrytext	: { *(.entrytext) }
+	.inittext	: { *(.inittext) }
+	.initdata	: { *(.initdata) }
+	__end_init = .;
+
+	.text		: { *(.text .text.*) }
+	.text32		: { *(.text32) }
+
+	.pecompat	: { *(.pecompat) }
+	PROVIDE(pecompat_fsize = setup_size - pecompat_fstart);
+
+	. = ALIGN(16);
+	.rodata		: { *(.rodata*) }
+
+	.videocards	: {
+		video_cards = .;
+		*(.videocards)
+		video_cards_end = .;
+	}
+
+	. = ALIGN(16);
+	.data		: { *(.data*) }
+
+	.signature	: {
+		setup_sig = .;
+		LONG(0x5a5aaa55)
+
+		setup_size = ALIGN(ABSOLUTE(.), 4096);
+		setup_sects = ABSOLUTE(setup_size / 512);
+		ASSERT(setup_sects >= 5, "The setup must be at least 5 sectors in size");
+		ASSERT(setup_sects <= 64, "The setup must be at most 64 sectors in size");
+	}
+
+	. = ALIGN(16);
+	.bss		:
+	{
+		__bss_start = .;
+		*(.bss)
+		__bss_end = .;
+	}
+	. = ALIGN(16);
+	_end = .;
+
+	/DISCARD/	: {
+		*(.note*)
+	}
+
+	/*
+	 * The ASSERT() sink to . is intentional, for binutils 2.14 compatibility:
+	 */
+	. = ASSERT(_end <= 0x8000, "Setup too big!");
+	. = ASSERT(hdr == 0x1f1, "The setup header has the wrong offset!");
+	/* Necessary for the very-old-loader check to work... */
+	. = ASSERT(__end_init <= 5*512, "init sections too big!");
+
+}

linux-7.2.3/arch/x86/boot/startup/Makefile

@@ -0,0 +1,52 @@
+# SPDX-License-Identifier: GPL-2.0
+
+KBUILD_AFLAGS		+= -D__DISABLE_EXPORTS
+KBUILD_CFLAGS		+= -D__DISABLE_EXPORTS -mcmodel=small -fPIC \
+			   -Os -DDISABLE_BRANCH_PROFILING \
+			   $(DISABLE_STACKLEAK_PLUGIN) \
+			   $(DISABLE_LATENT_ENTROPY_PLUGIN) \
+			   -fno-stack-protector -D__NO_FORTIFY \
+			   -fno-jump-tables \
+			   -include $(srctree)/include/linux/hidden.h
+
+# disable ftrace hooks and LTO
+KBUILD_CFLAGS	:= $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS))
+KBUILD_CFLAGS	:= $(filter-out $(CC_FLAGS_LTO),$(KBUILD_CFLAGS))
+KASAN_SANITIZE	:= n
+KCSAN_SANITIZE	:= n
+KMSAN_SANITIZE	:= n
+UBSAN_SANITIZE	:= n
+KCOV_INSTRUMENT	:= n
+
+obj-$(CONFIG_X86_64)		+= gdt_idt.o map_kernel.o
+obj-$(CONFIG_AMD_MEM_ENCRYPT)	+= sme.o sev-startup.o
+pi-objs				:= $(patsubst %.o,$(obj)/%.o,$(obj-y))
+
+lib-$(CONFIG_X86_64)		+= la57toggle.o
+lib-$(CONFIG_EFI_MIXED)		+= efi-mixed.o
+
+#
+# Disable objtool validation for all library code, which is intended
+# to be linked into the decompressor or the EFI stub but not vmlinux
+#
+$(patsubst %.o,$(obj)/%.o,$(lib-y)): OBJECT_FILES_NON_STANDARD := y
+
+#
+# Invoke objtool for each object individually to check for absolute
+# relocations, even if other objtool actions are being deferred.
+#
+$(pi-objs): objtool-enabled	= 1
+$(pi-objs): objtool-args	= $(if $(delay-objtool),--dry-run,$(objtool-args-y)) --noabs
+
+#
+# Confine the startup code by prefixing all symbols with __pi_ (for position
+# independent). This ensures that startup code can only call other startup
+# code, or code that has explicitly been made accessible to it via a symbol
+# alias.
+#
+$(obj)/%.pi.o: OBJCOPYFLAGS := --prefix-symbols=__pi_
+$(obj)/%.pi.o: $(obj)/%.o FORCE
+	$(call if_changed,objcopy)
+
+targets	+= $(obj-y)
+obj-y	:= $(patsubst %.o,%.pi.o,$(obj-y))

linux-7.2.3/arch/x86/boot/startup/efi-mixed.S

@@ -0,0 +1,253 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2014, 2015 Intel Corporation; author Matt Fleming
+ *
+ * Early support for invoking 32-bit EFI services from a 64-bit kernel.
+ *
+ * Because this thunking occurs before ExitBootServices() we have to
+ * restore the firmware's 32-bit GDT and IDT before we make EFI service
+ * calls.
+ *
+ * On the plus side, we don't have to worry about mangling 64-bit
+ * addresses into 32-bits because we're executing with an identity
+ * mapped pagetable and haven't transitioned to 64-bit virtual addresses
+ * yet.
+ */
+
+#include <linux/linkage.h>
+#include <asm/desc_defs.h>
+#include <asm/msr.h>
+#include <asm/page_types.h>
+#include <asm/pgtable_types.h>
+#include <asm/processor-flags.h>
+#include <asm/segment.h>
+
+	.text
+	.code32
+#ifdef CONFIG_EFI_HANDOVER_PROTOCOL
+SYM_FUNC_START(efi32_stub_entry)
+	call	1f
+1:	popl	%ecx
+
+	/* Clear BSS */
+	xorl	%eax, %eax
+	leal	(_bss - 1b)(%ecx), %edi
+	leal	(_ebss - 1b)(%ecx), %ecx
+	subl	%edi, %ecx
+	shrl	$2, %ecx
+	cld
+	rep	stosl
+
+	add	$0x4, %esp		/* Discard return address */
+	movl	8(%esp), %ebx		/* struct boot_params pointer */
+	jmp	efi32_startup
+SYM_FUNC_END(efi32_stub_entry)
+#endif
+
+/*
+ * Called using a far call from __efi64_thunk() below, using the x86_64 SysV
+ * ABI (except for R8/R9 which are inaccessible to 32-bit code - EAX/EBX are
+ * used instead).  EBP+16 points to the arguments passed via the stack.
+ *
+ * The first argument (EDI) is a pointer to the boot service or protocol, to
+ * which the remaining arguments are passed, each truncated to 32 bits.
+ */
+SYM_FUNC_START_LOCAL(efi_enter32)
+	/*
+	 * Convert x86-64 SysV ABI params to i386 ABI
+	 */
+	pushl	32(%ebp)	/* Up to 3 args passed via the stack */
+	pushl	24(%ebp)
+	pushl	16(%ebp)
+	pushl	%ebx		/* R9 */
+	pushl	%eax		/* R8 */
+	pushl	%ecx
+	pushl	%edx
+	pushl	%esi
+
+	/* Disable paging */
+	movl	%cr0, %eax
+	btrl	$X86_CR0_PG_BIT, %eax
+	movl	%eax, %cr0
+
+	/* Disable long mode via EFER */
+	movl	$MSR_EFER, %ecx
+	rdmsr
+	btrl	$_EFER_LME, %eax
+	wrmsr
+
+	call	*%edi
+
+	/* We must preserve return value */
+	movl	%eax, %edi
+
+	call	efi32_enable_long_mode
+
+	addl	$32, %esp
+	movl	%edi, %eax
+	lret
+SYM_FUNC_END(efi_enter32)
+
+	.code64
+SYM_FUNC_START(__efi64_thunk)
+	push	%rbp
+	movl	%esp, %ebp
+	push	%rbx
+
+	/* Move args #5 and #6 into 32-bit accessible registers */
+	movl	%r8d, %eax
+	movl	%r9d, %ebx
+
+	lcalll	*efi32_call(%rip)
+
+	pop	%rbx
+	pop	%rbp
+	RET
+SYM_FUNC_END(__efi64_thunk)
+
+	.code32
+SYM_FUNC_START_LOCAL(efi32_enable_long_mode)
+	movl	%cr4, %eax
+	btsl	$(X86_CR4_PAE_BIT), %eax
+	movl	%eax, %cr4
+
+	movl	$MSR_EFER, %ecx
+	rdmsr
+	btsl	$_EFER_LME, %eax
+	wrmsr
+
+	/* Disable interrupts - the firmware's IDT does not work in long mode */
+	cli
+
+	/* Enable paging */
+	movl	%cr0, %eax
+	btsl	$X86_CR0_PG_BIT, %eax
+	movl	%eax, %cr0
+	ret
+SYM_FUNC_END(efi32_enable_long_mode)
+
+/*
+ * This is the common EFI stub entry point for mixed mode. It sets up the GDT
+ * and page tables needed for 64-bit execution, after which it calls the
+ * common 64-bit EFI entrypoint efi_stub_entry().
+ *
+ * Arguments:	0(%esp)	image handle
+ * 		4(%esp)	EFI system table pointer
+ *		%ebx	struct boot_params pointer (or NULL)
+ *
+ * Since this is the point of no return for ordinary execution, no registers
+ * are considered live except for the function parameters. [Note that the EFI
+ * stub may still exit and return to the firmware using the Exit() EFI boot
+ * service.]
+ */
+SYM_FUNC_START_LOCAL(efi32_startup)
+	movl	%esp, %ebp
+
+	subl	$8, %esp
+	sgdtl	(%esp)			/* Save GDT descriptor to the stack */
+	movl	2(%esp), %esi		/* Existing GDT pointer */
+	movzwl	(%esp), %ecx		/* Existing GDT limit */
+	inc	%ecx			/* Existing GDT size */
+	andl	$~7, %ecx		/* Ensure size is multiple of 8 */
+
+	subl	%ecx, %esp		/* Allocate new GDT */
+	andl	$~15, %esp		/* Realign the stack */
+	movl	%esp, %edi		/* New GDT address */
+	leal	7(%ecx), %eax		/* New GDT limit */
+	pushw	%cx			/* Push 64-bit CS (for LJMP below) */
+	pushl	%edi			/* Push new GDT address */
+	pushw	%ax			/* Push new GDT limit */
+
+	/* Copy GDT to the stack and add a 64-bit code segment at the end */
+	movl	$GDT_ENTRY(DESC_CODE64, 0, 0xfffff) & 0xffffffff, (%edi,%ecx)
+	movl	$GDT_ENTRY(DESC_CODE64, 0, 0xfffff) >> 32, 4(%edi,%ecx)
+	shrl	$2, %ecx
+	cld
+	rep	movsl			/* Copy the firmware GDT */
+	lgdtl	(%esp)			/* Switch to the new GDT */
+
+	call	1f
+1:	pop	%edi
+
+	/* Record mixed mode entry */
+	movb	$0x0, (efi_is64 - 1b)(%edi)
+
+	/* Set up indirect far call to re-enter 32-bit mode */
+	leal	(efi32_call - 1b)(%edi), %eax
+	addl	%eax, (%eax)
+	movw	%cs, 4(%eax)
+
+	/* Disable paging */
+	movl	%cr0, %eax
+	btrl	$X86_CR0_PG_BIT, %eax
+	movl	%eax, %cr0
+
+	/* Set up 1:1 mapping */
+	leal	(pte - 1b)(%edi), %eax
+	movl	$_PAGE_PRESENT | _PAGE_RW | _PAGE_PSE, %ecx
+	leal	(_PAGE_PRESENT | _PAGE_RW)(%eax), %edx
+2:	movl	%ecx, (%eax)
+	addl	$8, %eax
+	addl	$PMD_SIZE, %ecx
+	jnc	2b
+
+	movl	$PAGE_SIZE, %ecx
+	.irpc	l, 0123
+	movl	%edx, \l * 8(%eax)
+	addl	%ecx, %edx
+	.endr
+	addl	%ecx, %eax
+	movl	%edx, (%eax)
+	movl	%eax, %cr3
+
+	call	efi32_enable_long_mode
+
+	/* Set up far jump to 64-bit mode (CS is already on the stack) */
+	leal	(efi_stub_entry - 1b)(%edi), %eax
+	movl	%eax, 2(%esp)
+
+	movl	0(%ebp), %edi
+	movl	4(%ebp), %esi
+	movl	%ebx, %edx
+	ljmpl	*2(%esp)
+SYM_FUNC_END(efi32_startup)
+
+/*
+ * efi_status_t efi32_pe_entry(efi_handle_t image_handle,
+ *			       efi_system_table_32_t *sys_table)
+ */
+SYM_FUNC_START(efi32_pe_entry)
+	pushl	%ebx				// save callee-save registers
+
+	/* Check whether the CPU supports long mode */
+	movl	$0x80000001, %eax		// assume extended info support
+	cpuid
+	btl	$29, %edx			// check long mode bit
+	jnc	1f
+	leal	8(%esp), %esp			// preserve stack alignment
+	xor	%ebx, %ebx			// no struct boot_params pointer
+	jmp	efi32_startup			// only ESP and EBX remain live
+1:	movl	$0x80000003, %eax		// EFI_UNSUPPORTED
+	popl	%ebx
+	RET
+SYM_FUNC_END(efi32_pe_entry)
+
+#ifdef CONFIG_EFI_HANDOVER_PROTOCOL
+	.org	efi32_stub_entry + 0x200
+	.code64
+SYM_FUNC_START_NOALIGN(efi64_stub_entry)
+	jmp	efi_handover_entry
+SYM_FUNC_END(efi64_stub_entry)
+#endif
+
+	.data
+	.balign	8
+SYM_DATA_START_LOCAL(efi32_call)
+	.long	efi_enter32 - .
+	.word	0x0
+SYM_DATA_END(efi32_call)
+SYM_DATA(efi_is64, .byte 1)
+
+	.bss
+	.balign PAGE_SIZE
+SYM_DATA_LOCAL(pte, .fill 6 * PAGE_SIZE, 1, 0)

linux-7.2.3/arch/x86/boot/startup/exports.h

@@ -0,0 +1,14 @@
+
+/*
+ * The symbols below are functions that are implemented by the startup code,
+ * but called at runtime by the SEV code residing in the core kernel.
+ */
+PROVIDE(early_set_pages_state		= __pi_early_set_pages_state);
+PROVIDE(early_snp_set_memory_private	= __pi_early_snp_set_memory_private);
+PROVIDE(early_snp_set_memory_shared	= __pi_early_snp_set_memory_shared);
+PROVIDE(get_hv_features			= __pi_get_hv_features);
+PROVIDE(sev_es_terminate		= __pi_sev_es_terminate);
+PROVIDE(snp_cpuid			= __pi_snp_cpuid);
+PROVIDE(snp_cpuid_get_table		= __pi_snp_cpuid_get_table);
+PROVIDE(svsm_issue_call			= __pi_svsm_issue_call);
+PROVIDE(svsm_process_result_codes	= __pi_svsm_process_result_codes);

linux-7.2.3/arch/x86/boot/startup/gdt_idt.c

@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/linkage.h>
+#include <linux/types.h>
+
+#include <asm/desc.h>
+#include <asm/init.h>
+#include <asm/setup.h>
+#include <asm/sev.h>
+#include <asm/trapnr.h>
+
+/*
+ * Data structures and code used for IDT setup in head_64.S. The bringup-IDT is
+ * used until the idt_table takes over. On the boot CPU this happens in
+ * x86_64_start_kernel(), on secondary CPUs in start_secondary(). In both cases
+ * this happens in the functions called from head_64.S.
+ *
+ * The idt_table can't be used that early because all the code modifying it is
+ * in idt.c and can be instrumented by tracing or KASAN, which both don't work
+ * during early CPU bringup. Also the idt_table has the runtime vectors
+ * configured which require certain CPU state to be setup already (like TSS),
+ * which also hasn't happened yet in early CPU bringup.
+ */
+static gate_desc bringup_idt_table[NUM_EXCEPTION_VECTORS] __page_aligned_data;
+
+/* This may run while still in the direct mapping */
+void startup_64_load_idt(void *vc_handler)
+{
+	struct desc_ptr desc = {
+		.address = (unsigned long)rip_rel_ptr(bringup_idt_table),
+		.size    = sizeof(bringup_idt_table) - 1,
+	};
+	struct idt_data data;
+	gate_desc idt_desc;
+
+	/* @vc_handler is set only for a VMM Communication Exception */
+	if (vc_handler) {
+		init_idt_data(&data, X86_TRAP_VC, vc_handler);
+		idt_init_desc(&idt_desc, &data);
+		native_write_idt_entry((gate_desc *)desc.address, X86_TRAP_VC, &idt_desc);
+	}
+
+	native_load_idt(&desc);
+}
+
+/*
+ * Setup boot CPU state needed before kernel switches to virtual addresses.
+ */
+void __init startup_64_setup_gdt_idt(void)
+{
+	struct gdt_page *gp = rip_rel_ptr((void *)(__force unsigned long)&gdt_page);
+	void *handler = NULL;
+
+	struct desc_ptr startup_gdt_descr = {
+		.address = (unsigned long)gp->gdt,
+		.size    = GDT_SIZE - 1,
+	};
+
+	/* Load GDT */
+	native_load_gdt(&startup_gdt_descr);
+
+	/* New GDT is live - reload data segment registers */
+	asm volatile("movl %%eax, %%ds\n"
+		     "movl %%eax, %%ss\n"
+		     "movl %%eax, %%es\n" : : "a"(__KERNEL_DS) : "memory");
+
+	if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT))
+		handler = rip_rel_ptr(vc_no_ghcb);
+
+	startup_64_load_idt(handler);
+}

linux-7.2.3/arch/x86/boot/startup/la57toggle.S

@@ -0,0 +1,111 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <linux/linkage.h>
+#include <asm/segment.h>
+#include <asm/boot.h>
+#include <asm/msr.h>
+#include <asm/processor-flags.h>
+
+/*
+ * This is the 32-bit trampoline that will be copied over to low memory. It
+ * will be called using the ordinary 64-bit calling convention from code
+ * running in 64-bit mode.
+ *
+ * Return address is at the top of the stack (might be above 4G).
+ * The first argument (EDI) contains the address of the temporary PGD level
+ * page table in 32-bit addressable memory which will be programmed into
+ * register CR3.
+ */
+
+	.section ".rodata", "a", @progbits
+SYM_CODE_START(trampoline_32bit_src)
+	/*
+	 * Preserve callee save 64-bit registers on the stack: this is
+	 * necessary because the architecture does not guarantee that GPRs will
+	 * retain their full 64-bit values across a 32-bit mode switch.
+	 */
+	pushq	%r15
+	pushq	%r14
+	pushq	%r13
+	pushq	%r12
+	pushq	%rbp
+	pushq	%rbx
+
+	/* Preserve top half of RSP in a legacy mode GPR to avoid truncation */
+	movq	%rsp, %rbx
+	shrq	$32, %rbx
+
+	/* Switch to compatibility mode (CS.L = 0 CS.D = 1) via far return */
+	pushq	$__KERNEL32_CS
+	leaq	0f(%rip), %rax
+	pushq	%rax
+	lretq
+
+	/*
+	 * The 32-bit code below will do a far jump back to long mode and end
+	 * up here after reconfiguring the number of paging levels. First, the
+	 * stack pointer needs to be restored to its full 64-bit value before
+	 * the callee save register contents can be popped from the stack.
+	 */
+.Lret:
+	shlq	$32, %rbx
+	orq	%rbx, %rsp
+
+	/* Restore the preserved 64-bit registers */
+	popq	%rbx
+	popq	%rbp
+	popq	%r12
+	popq	%r13
+	popq	%r14
+	popq	%r15
+	retq
+
+	.code32
+0:
+	/* Disable paging */
+	movl	%cr0, %eax
+	btrl	$X86_CR0_PG_BIT, %eax
+	movl	%eax, %cr0
+
+	/* Point CR3 to the trampoline's new top level page table */
+	movl	%edi, %cr3
+
+	/* Set EFER.LME=1 as a precaution in case hypervsior pulls the rug */
+	movl	$MSR_EFER, %ecx
+	rdmsr
+	btsl	$_EFER_LME, %eax
+	/* Avoid writing EFER if no change was made (for TDX guest) */
+	jc	1f
+	wrmsr
+1:
+	/* Toggle CR4.LA57 */
+	movl	%cr4, %eax
+	btcl	$X86_CR4_LA57_BIT, %eax
+	movl	%eax, %cr4
+
+	/* Enable paging again. */
+	movl	%cr0, %eax
+	btsl	$X86_CR0_PG_BIT, %eax
+	movl	%eax, %cr0
+
+	/*
+	 * Return to the 64-bit calling code using LJMP rather than LRET, to
+	 * avoid the need for a 32-bit addressable stack. The destination
+	 * address will be adjusted after the template code is copied into a
+	 * 32-bit addressable buffer.
+	 */
+.Ljmp:	ljmpl	$__KERNEL_CS, $(.Lret - trampoline_32bit_src)
+SYM_CODE_END(trampoline_32bit_src)
+
+/*
+ * This symbol is placed right after trampoline_32bit_src() so its address can
+ * be used to infer the size of the trampoline code.
+ */
+SYM_DATA(trampoline_ljmp_imm_offset, .word  .Ljmp + 1 - trampoline_32bit_src)
+
+	/*
+         * The trampoline code has a size limit.
+         * Make sure we fail to compile if the trampoline code grows
+         * beyond TRAMPOLINE_32BIT_CODE_SIZE bytes.
+	 */
+	.org	trampoline_32bit_src + TRAMPOLINE_32BIT_CODE_SIZE

linux-7.2.3/arch/x86/boot/startup/map_kernel.c

@@ -0,0 +1,217 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/init.h>
+#include <linux/linkage.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/pgtable.h>
+
+#include <asm/init.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <asm/sev.h>
+
+extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD];
+extern unsigned int next_early_pgt;
+
+static inline bool check_la57_support(void)
+{
+	/*
+	 * 5-level paging is detected and enabled at kernel decompression
+	 * stage. Only check if it has been enabled there.
+	 */
+	if (!(native_read_cr4() & X86_CR4_LA57))
+		return false;
+
+	__pgtable_l5_enabled	= 1;
+	pgdir_shift		= 48;
+	ptrs_per_p4d		= 512;
+
+	return true;
+}
+
+static unsigned long __init sme_postprocess_startup(struct boot_params *bp,
+						    pmdval_t *pmd,
+						    unsigned long p2v_offset)
+{
+	unsigned long paddr, paddr_end;
+	int i;
+
+	/* Encrypt the kernel and related (if SME is active) */
+	sme_encrypt_kernel(bp);
+
+	/*
+	 * Clear the memory encryption mask from the .bss..decrypted section.
+	 * The bss section will be memset to zero later in the initialization so
+	 * there is no need to zero it after changing the memory encryption
+	 * attribute.
+	 */
+	if (sme_get_me_mask()) {
+		paddr = (unsigned long)rip_rel_ptr(__start_bss_decrypted);
+		paddr_end = (unsigned long)rip_rel_ptr(__end_bss_decrypted);
+
+		for (; paddr < paddr_end; paddr += PMD_SIZE) {
+			/*
+			 * On SNP, transition the page to shared in the RMP table so that
+			 * it is consistent with the page table attribute change.
+			 *
+			 * __start_bss_decrypted has a virtual address in the high range
+			 * mapping (kernel .text). PVALIDATE, by way of
+			 * early_snp_set_memory_shared(), requires a valid virtual
+			 * address but the kernel is currently running off of the identity
+			 * mapping so use the PA to get a *currently* valid virtual address.
+			 */
+			early_snp_set_memory_shared(paddr, paddr, PTRS_PER_PMD);
+
+			i = pmd_index(paddr - p2v_offset);
+			pmd[i] -= sme_get_me_mask();
+		}
+	}
+
+	/*
+	 * Return the SME encryption mask (if SME is active) to be used as a
+	 * modifier for the initial pgdir entry programmed into CR3.
+	 */
+	return sme_get_me_mask();
+}
+
+/*
+ * This code is compiled using PIC codegen because it will execute from the
+ * early 1:1 mapping of memory, which deviates from the mapping expected by the
+ * linker. Due to this deviation, taking the address of a global variable will
+ * produce an ambiguous result when using the plain & operator.  Instead,
+ * rip_rel_ptr() must be used, which will return the RIP-relative address in
+ * the 1:1 mapping of memory. Kernel virtual addresses can be determined by
+ * subtracting p2v_offset from the RIP-relative address.
+ */
+unsigned long __init __startup_64(unsigned long p2v_offset,
+				  struct boot_params *bp)
+{
+	pmd_t (*early_pgts)[PTRS_PER_PMD] = rip_rel_ptr(early_dynamic_pgts);
+	unsigned long physaddr = (unsigned long)rip_rel_ptr(_text);
+	unsigned long va_text, va_end;
+	unsigned long pgtable_flags;
+	unsigned long load_delta;
+	pgdval_t *pgd;
+	p4dval_t *p4d;
+	pudval_t *pud;
+	pmdval_t *pmd, pmd_entry;
+	bool la57;
+	int i;
+
+	la57 = check_la57_support();
+
+	/* Is the address too large? */
+	if (physaddr >> MAX_PHYSMEM_BITS)
+		for (;;);
+
+	/*
+	 * Compute the delta between the address I am compiled to run at
+	 * and the address I am actually running at.
+	 */
+	phys_base = load_delta = __START_KERNEL_map + p2v_offset;
+
+	/* Is the address not 2M aligned? */
+	if (load_delta & ~PMD_MASK)
+		for (;;);
+
+	va_text = physaddr - p2v_offset;
+	va_end  = (unsigned long)rip_rel_ptr(_end) - p2v_offset;
+
+	/* Include the SME encryption mask in the fixup value */
+	load_delta += sme_get_me_mask();
+
+	/* Fixup the physical addresses in the page table */
+
+	pgd = rip_rel_ptr(early_top_pgt);
+	pgd[pgd_index(__START_KERNEL_map)] += load_delta;
+
+	if (la57) {
+		p4d = (p4dval_t *)rip_rel_ptr(level4_kernel_pgt);
+		p4d[MAX_PTRS_PER_P4D - 1] += load_delta;
+
+		pgd[pgd_index(__START_KERNEL_map)] = (pgdval_t)p4d | _PAGE_TABLE;
+	}
+
+	level3_kernel_pgt[PTRS_PER_PUD - 2].pud += load_delta;
+	level3_kernel_pgt[PTRS_PER_PUD - 1].pud += load_delta;
+
+	for (i = FIXMAP_PMD_TOP; i > FIXMAP_PMD_TOP - FIXMAP_PMD_NUM; i--)
+		level2_fixmap_pgt[i].pmd += load_delta;
+
+	/*
+	 * Set up the identity mapping for the switchover.  These
+	 * entries should *NOT* have the global bit set!  This also
+	 * creates a bunch of nonsense entries but that is fine --
+	 * it avoids problems around wraparound.
+	 */
+
+	pud = &early_pgts[0]->pmd;
+	pmd = &early_pgts[1]->pmd;
+	next_early_pgt = 2;
+
+	pgtable_flags = _KERNPG_TABLE_NOENC + sme_get_me_mask();
+
+	if (la57) {
+		p4d = &early_pgts[next_early_pgt++]->pmd;
+
+		i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
+		pgd[i + 0] = (pgdval_t)p4d + pgtable_flags;
+		pgd[i + 1] = (pgdval_t)p4d + pgtable_flags;
+
+		i = physaddr >> P4D_SHIFT;
+		p4d[(i + 0) % PTRS_PER_P4D] = (pgdval_t)pud + pgtable_flags;
+		p4d[(i + 1) % PTRS_PER_P4D] = (pgdval_t)pud + pgtable_flags;
+	} else {
+		i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
+		pgd[i + 0] = (pgdval_t)pud + pgtable_flags;
+		pgd[i + 1] = (pgdval_t)pud + pgtable_flags;
+	}
+
+	i = physaddr >> PUD_SHIFT;
+	pud[(i + 0) % PTRS_PER_PUD] = (pudval_t)pmd + pgtable_flags;
+	pud[(i + 1) % PTRS_PER_PUD] = (pudval_t)pmd + pgtable_flags;
+
+	pmd_entry = __PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL;
+	pmd_entry += sme_get_me_mask();
+	pmd_entry +=  physaddr;
+
+	for (i = 0; i < DIV_ROUND_UP(va_end - va_text, PMD_SIZE); i++) {
+		int idx = i + (physaddr >> PMD_SHIFT);
+
+		pmd[idx % PTRS_PER_PMD] = pmd_entry + i * PMD_SIZE;
+	}
+
+	/*
+	 * Fixup the kernel text+data virtual addresses. Note that
+	 * we might write invalid pmds, when the kernel is relocated
+	 * cleanup_highmap() fixes this up along with the mappings
+	 * beyond _end.
+	 *
+	 * Only the region occupied by the kernel image has so far
+	 * been checked against the table of usable memory regions
+	 * provided by the firmware, so invalidate pages outside that
+	 * region. A page table entry that maps to a reserved area of
+	 * memory would allow processor speculation into that area,
+	 * and on some hardware (particularly the UV platform) even
+	 * speculative access to some reserved areas is caught as an
+	 * error, causing the BIOS to halt the system.
+	 */
+
+	pmd = rip_rel_ptr(level2_kernel_pgt);
+
+	/* invalidate pages before the kernel image */
+	for (i = 0; i < pmd_index(va_text); i++)
+		pmd[i] &= ~_PAGE_PRESENT;
+
+	/* fixup pages that are part of the kernel image */
+	for (; i <= pmd_index(va_end); i++)
+		if (pmd[i] & _PAGE_PRESENT)
+			pmd[i] += load_delta;
+
+	/* invalidate pages after the kernel image */
+	for (; i < PTRS_PER_PMD; i++)
+		pmd[i] &= ~_PAGE_PRESENT;
+
+	return sme_postprocess_startup(bp, pmd, p2v_offset);
+}

linux-7.2.3/arch/x86/boot/startup/sev-shared.c

@@ -0,0 +1,762 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AMD Encrypted Register State Support
+ *
+ * Author: Joerg Roedel <jroedel@suse.de>
+ *
+ * This file is not compiled stand-alone. It contains code shared
+ * between the pre-decompression boot code and the running Linux kernel
+ * and is included directly into both code-bases.
+ */
+
+#include <asm/setup_data.h>
+
+#ifndef __BOOT_COMPRESSED
+#define has_cpuflag(f)			cpu_feature_enabled(f)
+#else
+#undef WARN
+#define WARN(condition, format...) (!!(condition))
+#endif
+
+/* Copy of the SNP firmware's CPUID page. */
+static struct snp_cpuid_table cpuid_table_copy __ro_after_init;
+
+/*
+ * These will be initialized based on CPUID table so that non-present
+ * all-zero leaves (for sparse tables) can be differentiated from
+ * invalid/out-of-range leaves. This is needed since all-zero leaves
+ * still need to be post-processed.
+ */
+static u32 cpuid_std_range_max __ro_after_init;
+static u32 cpuid_hyp_range_max __ro_after_init;
+static u32 cpuid_ext_range_max __ro_after_init;
+
+bool sev_snp_needs_sfw __section(".data");
+
+void __noreturn
+sev_es_terminate(unsigned int set, unsigned int reason)
+{
+	u64 val = GHCB_MSR_TERM_REQ;
+
+	/* Tell the hypervisor what went wrong. */
+	val |= GHCB_SEV_TERM_REASON(set, reason);
+
+	/* Request Guest Termination from Hypervisor */
+	sev_es_wr_ghcb_msr(val);
+	VMGEXIT();
+
+	while (true)
+		asm volatile("hlt\n" : : : "memory");
+}
+
+/*
+ * The hypervisor features are available from GHCB version 2 onward.
+ */
+u64 __init get_hv_features(void)
+{
+	u64 val;
+
+	if (ghcb_version < 2)
+		return 0;
+
+	sev_es_wr_ghcb_msr(GHCB_MSR_HV_FT_REQ);
+	VMGEXIT();
+
+	val = sev_es_rd_ghcb_msr();
+	if (GHCB_RESP_CODE(val) != GHCB_MSR_HV_FT_RESP)
+		return 0;
+
+	return GHCB_MSR_HV_FT_RESP_VAL(val);
+}
+
+int svsm_process_result_codes(struct svsm_call *call)
+{
+	switch (call->rax_out) {
+	case SVSM_SUCCESS:
+		return 0;
+	case SVSM_ERR_INCOMPLETE:
+	case SVSM_ERR_BUSY:
+		return -EAGAIN;
+	default:
+		return -EINVAL;
+	}
+}
+
+/*
+ * Issue a VMGEXIT to call the SVSM:
+ *   - Load the SVSM register state (RAX, RCX, RDX, R8 and R9)
+ *   - Set the CA call pending field to 1
+ *   - Issue VMGEXIT
+ *   - Save the SVSM return register state (RAX, RCX, RDX, R8 and R9)
+ *   - Perform atomic exchange of the CA call pending field
+ *
+ *   - See the "Secure VM Service Module for SEV-SNP Guests" specification for
+ *     details on the calling convention.
+ *     - The calling convention loosely follows the Microsoft X64 calling
+ *       convention by putting arguments in RCX, RDX, R8 and R9.
+ *     - RAX specifies the SVSM protocol/callid as input and the return code
+ *       as output.
+ */
+void svsm_issue_call(struct svsm_call *call, u8 *pending)
+{
+	register unsigned long rax asm("rax") = call->rax;
+	register unsigned long rcx asm("rcx") = call->rcx;
+	register unsigned long rdx asm("rdx") = call->rdx;
+	register unsigned long r8  asm("r8")  = call->r8;
+	register unsigned long r9  asm("r9")  = call->r9;
+
+	call->caa->call_pending = 1;
+
+	asm volatile("rep; vmmcall\n\t"
+		     : "+r" (rax), "+r" (rcx), "+r" (rdx), "+r" (r8), "+r" (r9)
+		     : : "memory");
+
+	*pending = xchg(&call->caa->call_pending, *pending);
+
+	call->rax_out = rax;
+	call->rcx_out = rcx;
+	call->rdx_out = rdx;
+	call->r8_out  = r8;
+	call->r9_out  = r9;
+}
+
+int svsm_perform_msr_protocol(struct svsm_call *call)
+{
+	u8 pending = 0;
+	u64 val, resp;
+
+	/*
+	 * When using the MSR protocol, be sure to save and restore
+	 * the current MSR value.
+	 */
+	val = sev_es_rd_ghcb_msr();
+
+	sev_es_wr_ghcb_msr(GHCB_MSR_VMPL_REQ_LEVEL(0));
+
+	svsm_issue_call(call, &pending);
+
+	resp = sev_es_rd_ghcb_msr();
+
+	sev_es_wr_ghcb_msr(val);
+
+	if (pending)
+		return -EINVAL;
+
+	if (GHCB_RESP_CODE(resp) != GHCB_MSR_VMPL_RESP)
+		return -EINVAL;
+
+	if (GHCB_MSR_VMPL_RESP_VAL(resp))
+		return -EINVAL;
+
+	return svsm_process_result_codes(call);
+}
+
+static int __sev_cpuid_hv(u32 fn, int reg_idx, u32 *reg)
+{
+	u64 val;
+
+	sev_es_wr_ghcb_msr(GHCB_CPUID_REQ(fn, reg_idx));
+	VMGEXIT();
+	val = sev_es_rd_ghcb_msr();
+	if (GHCB_RESP_CODE(val) != GHCB_MSR_CPUID_RESP)
+		return -EIO;
+
+	*reg = (val >> 32);
+
+	return 0;
+}
+
+static int __sev_cpuid_hv_msr(struct cpuid_leaf *leaf)
+{
+	int ret;
+
+	/*
+	 * MSR protocol does not support fetching non-zero subfunctions, but is
+	 * sufficient to handle current early-boot cases. Should that change,
+	 * make sure to report an error rather than ignoring the index and
+	 * grabbing random values. If this issue arises in the future, handling
+	 * can be added here to use GHCB-page protocol for cases that occur late
+	 * enough in boot that GHCB page is available.
+	 */
+	if (cpuid_function_is_indexed(leaf->fn) && leaf->subfn)
+		return -EINVAL;
+
+	ret =         __sev_cpuid_hv(leaf->fn, GHCB_CPUID_REQ_EAX, &leaf->eax);
+	ret = ret ? : __sev_cpuid_hv(leaf->fn, GHCB_CPUID_REQ_EBX, &leaf->ebx);
+	ret = ret ? : __sev_cpuid_hv(leaf->fn, GHCB_CPUID_REQ_ECX, &leaf->ecx);
+	ret = ret ? : __sev_cpuid_hv(leaf->fn, GHCB_CPUID_REQ_EDX, &leaf->edx);
+
+	return ret;
+}
+
+
+
+/*
+ * This may be called early while still running on the initial identity
+ * mapping. Use RIP-relative addressing to obtain the correct address
+ * while running with the initial identity mapping as well as the
+ * switch-over to kernel virtual addresses later.
+ */
+const struct snp_cpuid_table *snp_cpuid_get_table(void)
+{
+	return rip_rel_ptr(&cpuid_table_copy);
+}
+
+/*
+ * The SNP Firmware ABI, Revision 0.9, Section 7.1, details the use of
+ * XCR0_IN and XSS_IN to encode multiple versions of 0xD subfunctions 0
+ * and 1 based on the corresponding features enabled by a particular
+ * combination of XCR0 and XSS registers so that a guest can look up the
+ * version corresponding to the features currently enabled in its XCR0/XSS
+ * registers. The only values that differ between these versions/table
+ * entries is the enabled XSAVE area size advertised via EBX.
+ *
+ * While hypervisors may choose to make use of this support, it is more
+ * robust/secure for a guest to simply find the entry corresponding to the
+ * base/legacy XSAVE area size (XCR0=1 or XCR0=3), and then calculate the
+ * XSAVE area size using subfunctions 2 through 64, as documented in APM
+ * Volume 3, Rev 3.31, Appendix E.3.8, which is what is done here.
+ *
+ * Since base/legacy XSAVE area size is documented as 0x240, use that value
+ * directly rather than relying on the base size in the CPUID table.
+ *
+ * Return: XSAVE area size on success, 0 otherwise.
+ */
+static u32 snp_cpuid_calc_xsave_size(u64 xfeatures_en, bool compacted)
+{
+	const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table();
+	u64 xfeatures_found = 0;
+	u32 xsave_size = 0x240;
+	int i;
+
+	for (i = 0; i < cpuid_table->count; i++) {
+		const struct snp_cpuid_fn *e = &cpuid_table->fn[i];
+
+		if (!(e->eax_in == 0xD && e->ecx_in > 1 && e->ecx_in < 64))
+			continue;
+		if (!(xfeatures_en & (BIT_ULL(e->ecx_in))))
+			continue;
+		if (xfeatures_found & (BIT_ULL(e->ecx_in)))
+			continue;
+
+		xfeatures_found |= (BIT_ULL(e->ecx_in));
+
+		if (compacted)
+			xsave_size += e->eax;
+		else
+			xsave_size = max(xsave_size, e->eax + e->ebx);
+	}
+
+	/*
+	 * Either the guest set unsupported XCR0/XSS bits, or the corresponding
+	 * entries in the CPUID table were not present. This is not a valid
+	 * state to be in.
+	 */
+	if (xfeatures_found != (xfeatures_en & GENMASK_ULL(63, 2)))
+		return 0;
+
+	return xsave_size;
+}
+
+static bool
+snp_cpuid_get_validated_func(struct cpuid_leaf *leaf)
+{
+	const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table();
+	int i;
+
+	for (i = 0; i < cpuid_table->count; i++) {
+		const struct snp_cpuid_fn *e = &cpuid_table->fn[i];
+
+		if (e->eax_in != leaf->fn)
+			continue;
+
+		if (cpuid_function_is_indexed(leaf->fn) && e->ecx_in != leaf->subfn)
+			continue;
+
+		/*
+		 * For 0xD subfunctions 0 and 1, only use the entry corresponding
+		 * to the base/legacy XSAVE area size (XCR0=1 or XCR0=3, XSS=0).
+		 * See the comments above snp_cpuid_calc_xsave_size() for more
+		 * details.
+		 */
+		if (e->eax_in == 0xD && (e->ecx_in == 0 || e->ecx_in == 1))
+			if (!(e->xcr0_in == 1 || e->xcr0_in == 3) || e->xss_in)
+				continue;
+
+		leaf->eax = e->eax;
+		leaf->ebx = e->ebx;
+		leaf->ecx = e->ecx;
+		leaf->edx = e->edx;
+
+		return true;
+	}
+
+	return false;
+}
+
+static void snp_cpuid_hv_msr(void *ctx, struct cpuid_leaf *leaf)
+{
+	if (__sev_cpuid_hv_msr(leaf))
+		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_CPUID_HV);
+}
+
+static int
+snp_cpuid_postprocess(void (*cpuid_fn)(void *ctx, struct cpuid_leaf *leaf),
+		      void *ctx, struct cpuid_leaf *leaf)
+{
+	struct cpuid_leaf leaf_hv = *leaf;
+
+	switch (leaf->fn) {
+	case 0x1:
+		cpuid_fn(ctx, &leaf_hv);
+
+		/* initial APIC ID */
+		leaf->ebx = (leaf_hv.ebx & GENMASK(31, 24)) | (leaf->ebx & GENMASK(23, 0));
+		/* APIC enabled bit */
+		leaf->edx = (leaf_hv.edx & BIT(9)) | (leaf->edx & ~BIT(9));
+
+		/* OSXSAVE enabled bit */
+		if (native_read_cr4() & X86_CR4_OSXSAVE)
+			leaf->ecx |= BIT(27);
+		break;
+	case 0x7:
+		/* OSPKE enabled bit */
+		leaf->ecx &= ~BIT(4);
+		if (native_read_cr4() & X86_CR4_PKE)
+			leaf->ecx |= BIT(4);
+		break;
+	case 0xB:
+		leaf_hv.subfn = 0;
+		cpuid_fn(ctx, &leaf_hv);
+
+		/* extended APIC ID */
+		leaf->edx = leaf_hv.edx;
+		break;
+	case 0xD: {
+		bool compacted = false;
+		u64 xcr0 = 1, xss = 0;
+		u32 xsave_size;
+
+		if (leaf->subfn != 0 && leaf->subfn != 1)
+			return 0;
+
+		if (native_read_cr4() & X86_CR4_OSXSAVE)
+			xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
+		if (leaf->subfn == 1) {
+			/* Get XSS value if XSAVES is enabled. */
+			if (leaf->eax & BIT(3)) {
+				unsigned long lo, hi;
+
+				asm volatile("rdmsr" : "=a" (lo), "=d" (hi)
+						     : "c" (MSR_IA32_XSS));
+				xss = (hi << 32) | lo;
+			}
+
+			/*
+			 * The PPR and APM aren't clear on what size should be
+			 * encoded in 0xD:0x1:EBX when compaction is not enabled
+			 * by either XSAVEC (feature bit 1) or XSAVES (feature
+			 * bit 3) since SNP-capable hardware has these feature
+			 * bits fixed as 1. KVM sets it to 0 in this case, but
+			 * to avoid this becoming an issue it's safer to simply
+			 * treat this as unsupported for SNP guests.
+			 */
+			if (!(leaf->eax & (BIT(1) | BIT(3))))
+				return -EINVAL;
+
+			compacted = true;
+		}
+
+		xsave_size = snp_cpuid_calc_xsave_size(xcr0 | xss, compacted);
+		if (!xsave_size)
+			return -EINVAL;
+
+		leaf->ebx = xsave_size;
+		}
+		break;
+	case 0x8000001E:
+		cpuid_fn(ctx, &leaf_hv);
+
+		/* extended APIC ID */
+		leaf->eax = leaf_hv.eax;
+		/* compute ID */
+		leaf->ebx = (leaf->ebx & GENMASK(31, 8)) | (leaf_hv.ebx & GENMASK(7, 0));
+		/* node ID */
+		leaf->ecx = (leaf->ecx & GENMASK(31, 8)) | (leaf_hv.ecx & GENMASK(7, 0));
+		break;
+	default:
+		/* No fix-ups needed, use values as-is. */
+		break;
+	}
+
+	return 0;
+}
+
+/*
+ * Returns -EOPNOTSUPP if feature not enabled. Any other non-zero return value
+ * should be treated as fatal by caller.
+ */
+int snp_cpuid(void (*cpuid_fn)(void *ctx, struct cpuid_leaf *leaf),
+	      void *ctx, struct cpuid_leaf *leaf)
+{
+	const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table();
+
+	if (!cpuid_table->count)
+		return -EOPNOTSUPP;
+
+	if (!snp_cpuid_get_validated_func(leaf)) {
+		/*
+		 * Some hypervisors will avoid keeping track of CPUID entries
+		 * where all values are zero, since they can be handled the
+		 * same as out-of-range values (all-zero). This is useful here
+		 * as well as it allows virtually all guest configurations to
+		 * work using a single SNP CPUID table.
+		 *
+		 * To allow for this, there is a need to distinguish between
+		 * out-of-range entries and in-range zero entries, since the
+		 * CPUID table entries are only a template that may need to be
+		 * augmented with additional values for things like
+		 * CPU-specific information during post-processing. So if it's
+		 * not in the table, set the values to zero. Then, if they are
+		 * within a valid CPUID range, proceed with post-processing
+		 * using zeros as the initial values. Otherwise, skip
+		 * post-processing and just return zeros immediately.
+		 */
+		leaf->eax = leaf->ebx = leaf->ecx = leaf->edx = 0;
+
+		/* Skip post-processing for out-of-range zero leafs. */
+		if (!(leaf->fn <= cpuid_std_range_max ||
+		      (leaf->fn >= 0x40000000 && leaf->fn <= cpuid_hyp_range_max) ||
+		      (leaf->fn >= 0x80000000 && leaf->fn <= cpuid_ext_range_max)))
+			return 0;
+	}
+
+	return snp_cpuid_postprocess(cpuid_fn, ctx, leaf);
+}
+
+/*
+ * Boot VC Handler - This is the first VC handler during boot, there is no GHCB
+ * page yet, so it only supports the MSR based communication with the
+ * hypervisor and only the CPUID exit-code.
+ */
+void do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code)
+{
+	unsigned int subfn = lower_bits(regs->cx, 32);
+	unsigned int fn = lower_bits(regs->ax, 32);
+	u16 opcode = *(unsigned short *)regs->ip;
+	struct cpuid_leaf leaf;
+	int ret;
+
+	/* Only CPUID is supported via MSR protocol */
+	if (exit_code != SVM_EXIT_CPUID)
+		goto fail;
+
+	/* Is it really a CPUID insn? */
+	if (opcode != 0xa20f)
+		goto fail;
+
+	leaf.fn = fn;
+	leaf.subfn = subfn;
+
+	/*
+	 * If SNP is active, then snp_cpuid() uses the CPUID table to obtain the
+	 * CPUID values (with possible HV interaction during post-processing of
+	 * the values). But if SNP is not active (no CPUID table present), then
+	 * snp_cpuid() returns -EOPNOTSUPP so that an SEV-ES guest can call the
+	 * HV to obtain the CPUID information.
+	 */
+	ret = snp_cpuid(snp_cpuid_hv_msr, NULL, &leaf);
+	if (!ret)
+		goto cpuid_done;
+
+	if (ret != -EOPNOTSUPP)
+		goto fail;
+
+	/*
+	 * This is reached by a SEV-ES guest and needs to invoke the HV for
+	 * the CPUID data.
+	 */
+	if (__sev_cpuid_hv_msr(&leaf))
+		goto fail;
+
+cpuid_done:
+	regs->ax = leaf.eax;
+	regs->bx = leaf.ebx;
+	regs->cx = leaf.ecx;
+	regs->dx = leaf.edx;
+
+	/*
+	 * This is a VC handler and the #VC is only raised when SEV-ES is
+	 * active, which means SEV must be active too. Do sanity checks on the
+	 * CPUID results to make sure the hypervisor does not trick the kernel
+	 * into the no-sev path. This could map sensitive data unencrypted and
+	 * make it accessible to the hypervisor.
+	 *
+	 * In particular, check for:
+	 *	- Availability of CPUID leaf 0x8000001f
+	 *	- SEV CPUID bit.
+	 *
+	 * The hypervisor might still report the wrong C-bit position, but this
+	 * can't be checked here.
+	 */
+
+	if (fn == 0x80000000 && (regs->ax < 0x8000001f))
+		/* SEV leaf check */
+		goto fail;
+	else if ((fn == 0x8000001f && !(regs->ax & BIT(1))))
+		/* SEV bit */
+		goto fail;
+
+	/* Skip over the CPUID two-byte opcode */
+	regs->ip += 2;
+
+	return;
+
+fail:
+	/* Terminate the guest */
+	sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
+}
+
+struct cc_setup_data {
+	struct setup_data header;
+	u32 cc_blob_address;
+};
+
+/*
+ * Search for a Confidential Computing blob passed in as a setup_data entry
+ * via the Linux Boot Protocol.
+ */
+static __init
+struct cc_blob_sev_info *find_cc_blob_setup_data(struct boot_params *bp)
+{
+	struct cc_setup_data *sd = NULL;
+	struct setup_data *hdr;
+
+	hdr = (struct setup_data *)bp->hdr.setup_data;
+
+	while (hdr) {
+		if (hdr->type == SETUP_CC_BLOB) {
+			sd = (struct cc_setup_data *)hdr;
+			return (struct cc_blob_sev_info *)(unsigned long)sd->cc_blob_address;
+		}
+		hdr = (struct setup_data *)hdr->next;
+	}
+
+	return NULL;
+}
+
+/*
+ * Initialize the kernel's copy of the SNP CPUID table, and set up the
+ * pointer that will be used to access it.
+ *
+ * Maintaining a direct mapping of the SNP CPUID table used by firmware would
+ * be possible as an alternative, but the approach is brittle since the
+ * mapping needs to be updated in sync with all the changes to virtual memory
+ * layout and related mapping facilities throughout the boot process.
+ */
+static void __init setup_cpuid_table(const struct cc_blob_sev_info *cc_info)
+{
+	const struct snp_cpuid_table *cpuid_table_fw, *cpuid_table;
+	int i;
+
+	if (!cc_info || !cc_info->cpuid_phys || cc_info->cpuid_len < PAGE_SIZE)
+		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_CPUID);
+
+	cpuid_table_fw = (const struct snp_cpuid_table *)cc_info->cpuid_phys;
+	if (!cpuid_table_fw->count || cpuid_table_fw->count > SNP_CPUID_COUNT_MAX)
+		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_CPUID);
+
+	cpuid_table = snp_cpuid_get_table();
+	memcpy((void *)cpuid_table, cpuid_table_fw, sizeof(*cpuid_table));
+
+	/* Initialize CPUID ranges for range-checking. */
+	for (i = 0; i < cpuid_table->count; i++) {
+		const struct snp_cpuid_fn *fn = &cpuid_table->fn[i];
+
+		if (fn->eax_in == 0x0)
+			cpuid_std_range_max = fn->eax;
+		else if (fn->eax_in == 0x40000000)
+			cpuid_hyp_range_max = fn->eax;
+		else if (fn->eax_in == 0x80000000)
+			cpuid_ext_range_max = fn->eax;
+	}
+}
+
+static int svsm_call_msr_protocol(struct svsm_call *call)
+{
+	int ret;
+
+	do {
+		ret = svsm_perform_msr_protocol(call);
+	} while (ret == -EAGAIN);
+
+	return ret;
+}
+
+static void svsm_pval_4k_page(unsigned long paddr, bool validate,
+			      struct svsm_ca *caa, u64 caa_pa)
+{
+	struct svsm_pvalidate_call *pc;
+	struct svsm_call call = {};
+	unsigned long flags;
+	u64 pc_pa;
+
+	/*
+	 * This can be called very early in the boot, use native functions in
+	 * order to avoid paravirt issues.
+	 */
+	flags = native_local_irq_save();
+
+	call.caa = caa;
+
+	pc = (struct svsm_pvalidate_call *)call.caa->svsm_buffer;
+	pc_pa = caa_pa + offsetof(struct svsm_ca, svsm_buffer);
+
+	pc->num_entries = 1;
+	pc->cur_index   = 0;
+	pc->entry[0].page_size = RMP_PG_SIZE_4K;
+	pc->entry[0].action    = validate;
+	pc->entry[0].ignore_cf = 0;
+	pc->entry[0].rsvd      = 0;
+	pc->entry[0].pfn       = paddr >> PAGE_SHIFT;
+
+	/* Protocol 0, Call ID 1 */
+	call.rax = SVSM_CORE_CALL(SVSM_CORE_PVALIDATE);
+	call.rcx = pc_pa;
+
+	/*
+	 * Use the MSR protocol exclusively, so that this code is usable in
+	 * startup code where VA/PA translations of the GHCB page's address may
+	 * be problematic.
+	 */
+	if (svsm_call_msr_protocol(&call))
+		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PVALIDATE);
+
+	native_local_irq_restore(flags);
+}
+
+static void pvalidate_4k_page(unsigned long vaddr, unsigned long paddr,
+			      bool validate, struct svsm_ca *caa, u64 caa_pa)
+{
+	int ret;
+
+	if (snp_vmpl) {
+		svsm_pval_4k_page(paddr, validate, caa, caa_pa);
+	} else {
+		ret = pvalidate(vaddr, RMP_PG_SIZE_4K, validate);
+		if (ret)
+			sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PVALIDATE);
+	}
+
+	/*
+	 * If validating memory (making it private) and affected by the
+	 * cache-coherency vulnerability, perform the cache eviction mitigation.
+	 */
+	if (validate && sev_snp_needs_sfw)
+		sev_evict_cache((void *)vaddr, 1);
+}
+
+static void __page_state_change(unsigned long vaddr, unsigned long paddr,
+			        const struct psc_desc *desc)
+{
+	u64 val, msr;
+
+	/*
+	 * If private -> shared then invalidate the page before requesting the
+	 * state change in the RMP table.
+	 */
+	if (desc->op == SNP_PAGE_STATE_SHARED)
+		pvalidate_4k_page(vaddr, paddr, false, desc->ca, desc->caa_pa);
+
+	/* Save the current GHCB MSR value */
+	msr = sev_es_rd_ghcb_msr();
+
+	/* Issue VMGEXIT to change the page state in RMP table. */
+	sev_es_wr_ghcb_msr(GHCB_MSR_PSC_REQ_GFN(paddr >> PAGE_SHIFT, desc->op));
+	VMGEXIT();
+
+	/* Read the response of the VMGEXIT. */
+	val = sev_es_rd_ghcb_msr();
+	if ((GHCB_RESP_CODE(val) != GHCB_MSR_PSC_RESP) || GHCB_MSR_PSC_RESP_VAL(val))
+		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC);
+
+	/* Restore the GHCB MSR value */
+	sev_es_wr_ghcb_msr(msr);
+
+	/*
+	 * Now that page state is changed in the RMP table, validate it so that it is
+	 * consistent with the RMP entry.
+	 */
+	if (desc->op == SNP_PAGE_STATE_PRIVATE)
+		pvalidate_4k_page(vaddr, paddr, true, desc->ca, desc->caa_pa);
+}
+
+/*
+ * Maintain the GPA of the SVSM Calling Area (CA) in order to utilize the SVSM
+ * services needed when not running in VMPL0.
+ */
+static bool __init svsm_setup_ca(const struct cc_blob_sev_info *cc_info,
+				 void *page)
+{
+	struct snp_secrets_page *secrets_page;
+	struct snp_cpuid_table *cpuid_table;
+	unsigned int i;
+	u64 caa;
+
+	BUILD_BUG_ON(sizeof(*secrets_page) != PAGE_SIZE);
+
+	/*
+	 * Check if running at VMPL0.
+	 *
+	 * Use RMPADJUST (see the rmpadjust() function for a description of what
+	 * the instruction does) to update the VMPL1 permissions of a page. If
+	 * the guest is running at VMPL0, this will succeed and implies there is
+	 * no SVSM. If the guest is running at any other VMPL, this will fail.
+	 * Linux SNP guests only ever run at a single VMPL level so permission mask
+	 * changes of a lesser-privileged VMPL are a don't-care.
+	 *
+	 * Use a rip-relative reference to obtain the proper address, since this
+	 * routine is running identity mapped when called, both by the decompressor
+	 * code and the early kernel code.
+	 */
+	if (!rmpadjust((unsigned long)page, RMP_PG_SIZE_4K, 1))
+		return false;
+
+	/*
+	 * Not running at VMPL0, ensure everything has been properly supplied
+	 * for running under an SVSM.
+	 */
+	if (!cc_info || !cc_info->secrets_phys || cc_info->secrets_len != PAGE_SIZE)
+		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SECRETS_PAGE);
+
+	secrets_page = (struct snp_secrets_page *)cc_info->secrets_phys;
+	if (!secrets_page->svsm_size)
+		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_NO_SVSM);
+
+	if (!secrets_page->svsm_guest_vmpl)
+		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SVSM_VMPL0);
+
+	snp_vmpl = secrets_page->svsm_guest_vmpl;
+
+	caa = secrets_page->svsm_caa;
+
+	/*
+	 * An open-coded PAGE_ALIGNED() in order to avoid including
+	 * kernel-proper headers into the decompressor.
+	 */
+	if (caa & (PAGE_SIZE - 1))
+		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SVSM_CAA);
+
+	boot_svsm_caa_pa = caa;
+
+	/* Advertise the SVSM presence via CPUID. */
+	cpuid_table = (struct snp_cpuid_table *)snp_cpuid_get_table();
+	for (i = 0; i < cpuid_table->count; i++) {
+		struct snp_cpuid_fn *fn = &cpuid_table->fn[i];
+
+		if (fn->eax_in == 0x8000001f)
+			fn->eax |= BIT(28);
+	}
+
+	return true;
+}

linux-7.2.3/arch/x86/boot/startup/sev-startup.c

@@ -0,0 +1,221 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AMD Memory Encryption Support
+ *
+ * Copyright (C) 2019 SUSE
+ *
+ * Author: Joerg Roedel <jroedel@suse.de>
+ */
+
+#define pr_fmt(fmt)	"SEV: " fmt
+
+#include <linux/percpu-defs.h>
+#include <linux/cc_platform.h>
+#include <linux/printk.h>
+#include <linux/mm_types.h>
+#include <linux/set_memory.h>
+#include <linux/memblock.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/cpumask.h>
+#include <linux/efi.h>
+#include <linux/io.h>
+#include <linux/psp-sev.h>
+#include <uapi/linux/sev-guest.h>
+
+#include <asm/init.h>
+#include <asm/cpu_entry_area.h>
+#include <asm/stacktrace.h>
+#include <asm/sev.h>
+#include <asm/insn-eval.h>
+#include <asm/fpu/xcr.h>
+#include <asm/processor.h>
+#include <asm/realmode.h>
+#include <asm/setup.h>
+#include <asm/traps.h>
+#include <asm/svm.h>
+#include <asm/smp.h>
+#include <asm/cpu.h>
+#include <asm/apic.h>
+#include <asm/cpuid/api.h>
+#include <asm/cmdline.h>
+
+#include "../../coco/sev/internal.h"
+
+/* Include code shared with pre-decompression boot stage */
+#include "sev-shared.c"
+
+void
+early_set_pages_state(unsigned long vaddr, unsigned long paddr,
+		      unsigned long npages, const struct psc_desc *desc)
+{
+	unsigned long paddr_end;
+
+	vaddr = vaddr & PAGE_MASK;
+
+	paddr = paddr & PAGE_MASK;
+	paddr_end = paddr + (npages << PAGE_SHIFT);
+
+	while (paddr < paddr_end) {
+		__page_state_change(vaddr, paddr, desc);
+
+		vaddr += PAGE_SIZE;
+		paddr += PAGE_SIZE;
+	}
+}
+
+void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
+					 unsigned long npages)
+{
+	struct psc_desc d = {
+		SNP_PAGE_STATE_PRIVATE,
+		rip_rel_ptr(&boot_svsm_ca_page),
+		boot_svsm_caa_pa
+	};
+
+	/*
+	 * This can be invoked in early boot while running identity mapped, so
+	 * use an open coded check for SNP instead of using cc_platform_has().
+	 * This eliminates worries about jump tables or checking boot_cpu_data
+	 * in the cc_platform_has() function.
+	 */
+	if (!(sev_status & MSR_AMD64_SEV_SNP_ENABLED))
+		return;
+
+	 /*
+	  * Ask the hypervisor to mark the memory pages as private in the RMP
+	  * table.
+	  */
+	early_set_pages_state(vaddr, paddr, npages, &d);
+}
+
+void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,
+					unsigned long npages)
+{
+	struct psc_desc d = {
+		SNP_PAGE_STATE_SHARED,
+		rip_rel_ptr(&boot_svsm_ca_page),
+		boot_svsm_caa_pa
+	};
+
+	/*
+	 * This can be invoked in early boot while running identity mapped, so
+	 * use an open coded check for SNP instead of using cc_platform_has().
+	 * This eliminates worries about jump tables or checking boot_cpu_data
+	 * in the cc_platform_has() function.
+	 */
+	if (!(sev_status & MSR_AMD64_SEV_SNP_ENABLED))
+		return;
+
+	 /* Ask hypervisor to mark the memory pages shared in the RMP table. */
+	early_set_pages_state(vaddr, paddr, npages, &d);
+}
+
+/*
+ * Initial set up of SNP relies on information provided by the
+ * Confidential Computing blob, which can be passed to the kernel
+ * in the following ways, depending on how it is booted:
+ *
+ * - when booted via the boot/decompress kernel:
+ *   - via boot_params
+ *
+ * - when booted directly by firmware/bootloader (e.g. CONFIG_PVH):
+ *   - via a setup_data entry, as defined by the Linux Boot Protocol
+ *
+ * Scan for the blob in that order.
+ */
+static struct cc_blob_sev_info *__init find_cc_blob(struct boot_params *bp)
+{
+	struct cc_blob_sev_info *cc_info;
+
+	/* Boot kernel would have passed the CC blob via boot_params. */
+	if (bp->cc_blob_address) {
+		cc_info = (struct cc_blob_sev_info *)(unsigned long)bp->cc_blob_address;
+		goto found_cc_info;
+	}
+
+	/*
+	 * If kernel was booted directly, without the use of the
+	 * boot/decompression kernel, the CC blob may have been passed via
+	 * setup_data instead.
+	 */
+	cc_info = find_cc_blob_setup_data(bp);
+	if (!cc_info)
+		return NULL;
+
+found_cc_info:
+	if (cc_info->magic != CC_BLOB_SEV_HDR_MAGIC)
+		sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
+
+	return cc_info;
+}
+
+static void __init svsm_setup(struct cc_blob_sev_info *cc_info)
+{
+	struct snp_secrets_page *secrets = (void *)cc_info->secrets_phys;
+	struct svsm_call call = {};
+	u64 pa;
+
+	/*
+	 * Record the SVSM Calling Area address (CAA) if the guest is not
+	 * running at VMPL0. The CA will be used to communicate with the
+	 * SVSM to perform the SVSM services.
+	 */
+	if (!svsm_setup_ca(cc_info, rip_rel_ptr(&boot_svsm_ca_page)))
+		return;
+
+	/*
+	 * It is very early in the boot and the kernel is running identity
+	 * mapped but without having adjusted the pagetables to where the
+	 * kernel was loaded (physbase), so the get the CA address using
+	 * RIP-relative addressing.
+	 */
+	pa = (u64)rip_rel_ptr(&boot_svsm_ca_page);
+
+	/*
+	 * Switch over to the boot SVSM CA while the current CA is still 1:1
+	 * mapped and thus addressable with VA == PA. There is no GHCB at this
+	 * point so use the MSR protocol.
+	 *
+	 * SVSM_CORE_REMAP_CA call:
+	 *   RAX = 0 (Protocol=0, CallID=0)
+	 *   RCX = New CA GPA
+	 */
+	call.caa = (struct svsm_ca *)secrets->svsm_caa;
+	call.rax = SVSM_CORE_CALL(SVSM_CORE_REMAP_CA);
+	call.rcx = pa;
+
+	if (svsm_call_msr_protocol(&call))
+		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SVSM_CA_REMAP_FAIL);
+
+	boot_svsm_caa_pa = pa;
+}
+
+bool __init snp_init(struct boot_params *bp)
+{
+	struct cc_blob_sev_info *cc_info;
+
+	if (!bp)
+		return false;
+
+	cc_info = find_cc_blob(bp);
+	if (!cc_info)
+		return false;
+
+	if (cc_info->secrets_phys && cc_info->secrets_len == PAGE_SIZE)
+		sev_secrets_pa = cc_info->secrets_phys;
+	else
+		return false;
+
+	setup_cpuid_table(cc_info);
+
+	svsm_setup(cc_info);
+
+	/*
+	 * The CC blob will be used later to access the secrets page. Cache
+	 * it here like the boot kernel does.
+	 */
+	bp->cc_blob_address = (u32)(unsigned long)cc_info;
+
+	return true;
+}

linux-7.2.3/arch/x86/boot/startup/sme.c

@@ -0,0 +1,577 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AMD Memory Encryption Support
+ *
+ * Copyright (C) 2016 Advanced Micro Devices, Inc.
+ *
+ * Author: Tom Lendacky <thomas.lendacky@amd.com>
+ */
+
+/*
+ * Since we're dealing with identity mappings, physical and virtual
+ * addresses are the same, so override these defines which are ultimately
+ * used by the headers in misc.h.
+ */
+#define __pa(x)  ((unsigned long)(x))
+#define __va(x)  ((void *)((unsigned long)(x)))
+
+/*
+ * Special hack: we have to be careful, because no indirections are
+ * allowed here, and paravirt_ops is a kind of one. As it will only run in
+ * baremetal anyway, we just keep it from happening. (This list needs to
+ * be extended when new paravirt and debugging variants are added.)
+ */
+#undef CONFIG_PARAVIRT
+#undef CONFIG_PARAVIRT_XXL
+#undef CONFIG_PARAVIRT_SPINLOCKS
+#undef CONFIG_ARCH_HAS_LAZY_MMU_MODE
+
+/*
+ * This code runs before CPU feature bits are set. By default, the
+ * pgtable_l5_enabled() function uses bit X86_FEATURE_LA57 to determine if
+ * 5-level paging is active, so that won't work here. USE_EARLY_PGTABLE_L5
+ * is provided to handle this situation and, instead, use a variable that
+ * has been set by the early boot code.
+ */
+#define USE_EARLY_PGTABLE_L5
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/mem_encrypt.h>
+#include <linux/cc_platform.h>
+
+#include <asm/init.h>
+#include <asm/setup.h>
+#include <asm/sections.h>
+#include <asm/cpuid/api.h>
+#include <asm/coco.h>
+#include <asm/sev.h>
+
+#define PGD_FLAGS		_KERNPG_TABLE_NOENC
+#define P4D_FLAGS		_KERNPG_TABLE_NOENC
+#define PUD_FLAGS		_KERNPG_TABLE_NOENC
+#define PMD_FLAGS		_KERNPG_TABLE_NOENC
+
+#define PMD_FLAGS_LARGE		(__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL)
+
+#define PMD_FLAGS_DEC		PMD_FLAGS_LARGE
+#define PMD_FLAGS_DEC_WP	((PMD_FLAGS_DEC & ~_PAGE_LARGE_CACHE_MASK) | \
+				 (_PAGE_PAT_LARGE | _PAGE_PWT))
+
+#define PMD_FLAGS_ENC		(PMD_FLAGS_LARGE | _PAGE_ENC)
+
+#define PTE_FLAGS		(__PAGE_KERNEL_EXEC & ~_PAGE_GLOBAL)
+
+#define PTE_FLAGS_DEC		PTE_FLAGS
+#define PTE_FLAGS_DEC_WP	((PTE_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \
+				 (_PAGE_PAT | _PAGE_PWT))
+
+#define PTE_FLAGS_ENC		(PTE_FLAGS | _PAGE_ENC)
+
+struct sme_populate_pgd_data {
+	void    *pgtable_area;
+	pgd_t   *pgd;
+
+	pmdval_t pmd_flags;
+	pteval_t pte_flags;
+	unsigned long paddr;
+
+	unsigned long vaddr;
+	unsigned long vaddr_end;
+};
+
+/*
+ * This work area lives in the .init.scratch section, which lives outside of
+ * the kernel proper. It is sized to hold the intermediate copy buffer and
+ * more than enough pagetable pages.
+ *
+ * By using this section, the kernel can be encrypted in place and it
+ * avoids any possibility of boot parameters or initramfs images being
+ * placed such that the in-place encryption logic overwrites them.  This
+ * section is 2MB aligned to allow for simple pagetable setup using only
+ * PMD entries (see vmlinux.lds.S).
+ */
+static char sme_workarea[2 * PMD_SIZE] __section(".init.scratch");
+
+static void __init sme_clear_pgd(struct sme_populate_pgd_data *ppd)
+{
+	unsigned long pgd_start, pgd_end, pgd_size;
+	pgd_t *pgd_p;
+
+	pgd_start = ppd->vaddr & PGDIR_MASK;
+	pgd_end = ppd->vaddr_end & PGDIR_MASK;
+
+	pgd_size = (((pgd_end - pgd_start) / PGDIR_SIZE) + 1) * sizeof(pgd_t);
+
+	pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
+
+	memset(pgd_p, 0, pgd_size);
+}
+
+static pud_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
+{
+	pgd_t *pgd;
+	p4d_t *p4d;
+	pud_t *pud;
+	pmd_t *pmd;
+
+	pgd = ppd->pgd + pgd_index(ppd->vaddr);
+	if (pgd_none(*pgd)) {
+		p4d = ppd->pgtable_area;
+		memset(p4d, 0, sizeof(*p4d) * PTRS_PER_P4D);
+		ppd->pgtable_area += sizeof(*p4d) * PTRS_PER_P4D;
+		set_pgd(pgd, __pgd(PGD_FLAGS | __pa(p4d)));
+	}
+
+	p4d = p4d_offset(pgd, ppd->vaddr);
+	if (p4d_none(*p4d)) {
+		pud = ppd->pgtable_area;
+		memset(pud, 0, sizeof(*pud) * PTRS_PER_PUD);
+		ppd->pgtable_area += sizeof(*pud) * PTRS_PER_PUD;
+		set_p4d(p4d, __p4d(P4D_FLAGS | __pa(pud)));
+	}
+
+	pud = pud_offset(p4d, ppd->vaddr);
+	if (pud_none(*pud)) {
+		pmd = ppd->pgtable_area;
+		memset(pmd, 0, sizeof(*pmd) * PTRS_PER_PMD);
+		ppd->pgtable_area += sizeof(*pmd) * PTRS_PER_PMD;
+		set_pud(pud, __pud(PUD_FLAGS | __pa(pmd)));
+	}
+
+	if (pud_leaf(*pud))
+		return NULL;
+
+	return pud;
+}
+
+static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
+{
+	pud_t *pud;
+	pmd_t *pmd;
+
+	pud = sme_prepare_pgd(ppd);
+	if (!pud)
+		return;
+
+	pmd = pmd_offset(pud, ppd->vaddr);
+	if (pmd_leaf(*pmd))
+		return;
+
+	set_pmd(pmd, __pmd(ppd->paddr | ppd->pmd_flags));
+}
+
+static void __init sme_populate_pgd(struct sme_populate_pgd_data *ppd)
+{
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
+
+	pud = sme_prepare_pgd(ppd);
+	if (!pud)
+		return;
+
+	pmd = pmd_offset(pud, ppd->vaddr);
+	if (pmd_none(*pmd)) {
+		pte = ppd->pgtable_area;
+		memset(pte, 0, sizeof(*pte) * PTRS_PER_PTE);
+		ppd->pgtable_area += sizeof(*pte) * PTRS_PER_PTE;
+		set_pmd(pmd, __pmd(PMD_FLAGS | __pa(pte)));
+	}
+
+	if (pmd_leaf(*pmd))
+		return;
+
+	pte = pte_offset_kernel(pmd, ppd->vaddr);
+	if (pte_none(*pte))
+		set_pte(pte, __pte(ppd->paddr | ppd->pte_flags));
+}
+
+static void __init __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
+{
+	while (ppd->vaddr < ppd->vaddr_end) {
+		sme_populate_pgd_large(ppd);
+
+		ppd->vaddr += PMD_SIZE;
+		ppd->paddr += PMD_SIZE;
+	}
+}
+
+static void __init __sme_map_range_pte(struct sme_populate_pgd_data *ppd)
+{
+	while (ppd->vaddr < ppd->vaddr_end) {
+		sme_populate_pgd(ppd);
+
+		ppd->vaddr += PAGE_SIZE;
+		ppd->paddr += PAGE_SIZE;
+	}
+}
+
+static void __init __sme_map_range(struct sme_populate_pgd_data *ppd,
+				   pmdval_t pmd_flags, pteval_t pte_flags)
+{
+	unsigned long vaddr_end;
+
+	ppd->pmd_flags = pmd_flags;
+	ppd->pte_flags = pte_flags;
+
+	/* Save original end value since we modify the struct value */
+	vaddr_end = ppd->vaddr_end;
+
+	/* If start is not 2MB aligned, create PTE entries */
+	ppd->vaddr_end = ALIGN(ppd->vaddr, PMD_SIZE);
+	__sme_map_range_pte(ppd);
+
+	/* Create PMD entries */
+	ppd->vaddr_end = vaddr_end & PMD_MASK;
+	__sme_map_range_pmd(ppd);
+
+	/* If end is not 2MB aligned, create PTE entries */
+	ppd->vaddr_end = vaddr_end;
+	__sme_map_range_pte(ppd);
+}
+
+static void __init sme_map_range_encrypted(struct sme_populate_pgd_data *ppd)
+{
+	__sme_map_range(ppd, PMD_FLAGS_ENC, PTE_FLAGS_ENC);
+}
+
+static void __init sme_map_range_decrypted(struct sme_populate_pgd_data *ppd)
+{
+	__sme_map_range(ppd, PMD_FLAGS_DEC, PTE_FLAGS_DEC);
+}
+
+static void __init sme_map_range_decrypted_wp(struct sme_populate_pgd_data *ppd)
+{
+	__sme_map_range(ppd, PMD_FLAGS_DEC_WP, PTE_FLAGS_DEC_WP);
+}
+
+static unsigned long __init sme_pgtable_calc(unsigned long len)
+{
+	unsigned long entries = 0, tables = 0;
+
+	/*
+	 * Perform a relatively simplistic calculation of the pagetable
+	 * entries that are needed. Those mappings will be covered mostly
+	 * by 2MB PMD entries so we can conservatively calculate the required
+	 * number of P4D, PUD and PMD structures needed to perform the
+	 * mappings.  For mappings that are not 2MB aligned, PTE mappings
+	 * would be needed for the start and end portion of the address range
+	 * that fall outside of the 2MB alignment.  This results in, at most,
+	 * two extra pages to hold PTE entries for each range that is mapped.
+	 * Incrementing the count for each covers the case where the addresses
+	 * cross entries.
+	 */
+
+	/* PGDIR_SIZE is equal to P4D_SIZE on 4-level machine. */
+	if (PTRS_PER_P4D > 1)
+		entries += (DIV_ROUND_UP(len, PGDIR_SIZE) + 1) * sizeof(p4d_t) * PTRS_PER_P4D;
+	entries += (DIV_ROUND_UP(len, P4D_SIZE) + 1) * sizeof(pud_t) * PTRS_PER_PUD;
+	entries += (DIV_ROUND_UP(len, PUD_SIZE) + 1) * sizeof(pmd_t) * PTRS_PER_PMD;
+	entries += 2 * sizeof(pte_t) * PTRS_PER_PTE;
+
+	/*
+	 * Now calculate the added pagetable structures needed to populate
+	 * the new pagetables.
+	 */
+
+	if (PTRS_PER_P4D > 1)
+		tables += DIV_ROUND_UP(entries, PGDIR_SIZE) * sizeof(p4d_t) * PTRS_PER_P4D;
+	tables += DIV_ROUND_UP(entries, P4D_SIZE) * sizeof(pud_t) * PTRS_PER_PUD;
+	tables += DIV_ROUND_UP(entries, PUD_SIZE) * sizeof(pmd_t) * PTRS_PER_PMD;
+
+	return entries + tables;
+}
+
+void __init sme_encrypt_kernel(struct boot_params *bp)
+{
+	unsigned long workarea_start, workarea_end, workarea_len;
+	unsigned long execute_start, execute_end, execute_len;
+	unsigned long kernel_start, kernel_end, kernel_len;
+	unsigned long initrd_start, initrd_end, initrd_len;
+	struct sme_populate_pgd_data ppd;
+	unsigned long pgtable_area_len;
+	unsigned long decrypted_base;
+
+	/*
+	 * This is early code, use an open coded check for SME instead of
+	 * using cc_platform_has(). This eliminates worries about removing
+	 * instrumentation or checking boot_cpu_data in the cc_platform_has()
+	 * function.
+	 */
+	if (!sme_get_me_mask() || sev_status & MSR_AMD64_SEV_ENABLED)
+		return;
+
+	/*
+	 * Prepare for encrypting the kernel and initrd by building new
+	 * pagetables with the necessary attributes needed to encrypt the
+	 * kernel in place.
+	 *
+	 *   One range of virtual addresses will map the memory occupied
+	 *   by the kernel and initrd as encrypted.
+	 *
+	 *   Another range of virtual addresses will map the memory occupied
+	 *   by the kernel and initrd as decrypted and write-protected.
+	 *
+	 *     The use of write-protect attribute will prevent any of the
+	 *     memory from being cached.
+	 */
+
+	kernel_start = (unsigned long)rip_rel_ptr(_text);
+	kernel_end = ALIGN((unsigned long)rip_rel_ptr(_end), PMD_SIZE);
+	kernel_len = kernel_end - kernel_start;
+
+	initrd_start = 0;
+	initrd_end = 0;
+	initrd_len = 0;
+#ifdef CONFIG_BLK_DEV_INITRD
+	initrd_len = (unsigned long)bp->hdr.ramdisk_size |
+		     ((unsigned long)bp->ext_ramdisk_size << 32);
+	if (initrd_len) {
+		initrd_start = (unsigned long)bp->hdr.ramdisk_image |
+			       ((unsigned long)bp->ext_ramdisk_image << 32);
+		initrd_end = PAGE_ALIGN(initrd_start + initrd_len);
+		initrd_len = initrd_end - initrd_start;
+	}
+#endif
+
+	/*
+	 * Calculate required number of workarea bytes needed:
+	 *   executable encryption area size:
+	 *     stack page (PAGE_SIZE)
+	 *     encryption routine page (PAGE_SIZE)
+	 *     intermediate copy buffer (PMD_SIZE)
+	 *   pagetable structures for the encryption of the kernel
+	 *   pagetable structures for workarea (in case not currently mapped)
+	 */
+	execute_start = workarea_start = (unsigned long)rip_rel_ptr(sme_workarea);
+	execute_end = execute_start + (PAGE_SIZE * 2) + PMD_SIZE;
+	execute_len = execute_end - execute_start;
+
+	/*
+	 * One PGD for both encrypted and decrypted mappings and a set of
+	 * PUDs and PMDs for each of the encrypted and decrypted mappings.
+	 */
+	pgtable_area_len = sizeof(pgd_t) * PTRS_PER_PGD;
+	pgtable_area_len += sme_pgtable_calc(execute_end - kernel_start) * 2;
+	if (initrd_len)
+		pgtable_area_len += sme_pgtable_calc(initrd_len) * 2;
+
+	/* PUDs and PMDs needed in the current pagetables for the workarea */
+	pgtable_area_len += sme_pgtable_calc(execute_len + pgtable_area_len);
+
+	/*
+	 * The total workarea includes the executable encryption area and
+	 * the pagetable area. The start of the workarea is already 2MB
+	 * aligned, align the end of the workarea on a 2MB boundary so that
+	 * we don't try to create/allocate PTE entries from the workarea
+	 * before it is mapped.
+	 */
+	workarea_len = execute_len + pgtable_area_len;
+	workarea_end = ALIGN(workarea_start + workarea_len, PMD_SIZE);
+
+	/*
+	 * Set the address to the start of where newly created pagetable
+	 * structures (PGDs, PUDs and PMDs) will be allocated. New pagetable
+	 * structures are created when the workarea is added to the current
+	 * pagetables and when the new encrypted and decrypted kernel
+	 * mappings are populated.
+	 */
+	ppd.pgtable_area = (void *)execute_end;
+
+	/*
+	 * Make sure the current pagetable structure has entries for
+	 * addressing the workarea.
+	 */
+	ppd.pgd = (pgd_t *)native_read_cr3_pa();
+	ppd.paddr = workarea_start;
+	ppd.vaddr = workarea_start;
+	ppd.vaddr_end = workarea_end;
+	sme_map_range_decrypted(&ppd);
+
+	/* Flush the TLB - no globals so cr3 is enough */
+	native_write_cr3(__native_read_cr3());
+
+	/*
+	 * A new pagetable structure is being built to allow for the kernel
+	 * and initrd to be encrypted. It starts with an empty PGD that will
+	 * then be populated with new PUDs and PMDs as the encrypted and
+	 * decrypted kernel mappings are created.
+	 */
+	ppd.pgd = ppd.pgtable_area;
+	memset(ppd.pgd, 0, sizeof(pgd_t) * PTRS_PER_PGD);
+	ppd.pgtable_area += sizeof(pgd_t) * PTRS_PER_PGD;
+
+	/*
+	 * A different PGD index/entry must be used to get different
+	 * pagetable entries for the decrypted mapping. Choose the next
+	 * PGD index and convert it to a virtual address to be used as
+	 * the base of the mapping.
+	 */
+	decrypted_base = (pgd_index(workarea_end) + 1) & (PTRS_PER_PGD - 1);
+	if (initrd_len) {
+		unsigned long check_base;
+
+		check_base = (pgd_index(initrd_end) + 1) & (PTRS_PER_PGD - 1);
+		decrypted_base = max(decrypted_base, check_base);
+	}
+	decrypted_base <<= PGDIR_SHIFT;
+
+	/* Add encrypted kernel (identity) mappings */
+	ppd.paddr = kernel_start;
+	ppd.vaddr = kernel_start;
+	ppd.vaddr_end = kernel_end;
+	sme_map_range_encrypted(&ppd);
+
+	/* Add decrypted, write-protected kernel (non-identity) mappings */
+	ppd.paddr = kernel_start;
+	ppd.vaddr = kernel_start + decrypted_base;
+	ppd.vaddr_end = kernel_end + decrypted_base;
+	sme_map_range_decrypted_wp(&ppd);
+
+	if (initrd_len) {
+		/* Add encrypted initrd (identity) mappings */
+		ppd.paddr = initrd_start;
+		ppd.vaddr = initrd_start;
+		ppd.vaddr_end = initrd_end;
+		sme_map_range_encrypted(&ppd);
+		/*
+		 * Add decrypted, write-protected initrd (non-identity) mappings
+		 */
+		ppd.paddr = initrd_start;
+		ppd.vaddr = initrd_start + decrypted_base;
+		ppd.vaddr_end = initrd_end + decrypted_base;
+		sme_map_range_decrypted_wp(&ppd);
+	}
+
+	/* Add decrypted workarea mappings to both kernel mappings */
+	ppd.paddr = workarea_start;
+	ppd.vaddr = workarea_start;
+	ppd.vaddr_end = workarea_end;
+	sme_map_range_decrypted(&ppd);
+
+	ppd.paddr = workarea_start;
+	ppd.vaddr = workarea_start + decrypted_base;
+	ppd.vaddr_end = workarea_end + decrypted_base;
+	sme_map_range_decrypted(&ppd);
+
+	/* Perform the encryption */
+	sme_encrypt_execute(kernel_start, kernel_start + decrypted_base,
+			    kernel_len, workarea_start, (unsigned long)ppd.pgd);
+
+	if (initrd_len)
+		sme_encrypt_execute(initrd_start, initrd_start + decrypted_base,
+				    initrd_len, workarea_start,
+				    (unsigned long)ppd.pgd);
+
+	/*
+	 * At this point we are running encrypted.  Remove the mappings for
+	 * the decrypted areas - all that is needed for this is to remove
+	 * the PGD entry/entries.
+	 */
+	ppd.vaddr = kernel_start + decrypted_base;
+	ppd.vaddr_end = kernel_end + decrypted_base;
+	sme_clear_pgd(&ppd);
+
+	if (initrd_len) {
+		ppd.vaddr = initrd_start + decrypted_base;
+		ppd.vaddr_end = initrd_end + decrypted_base;
+		sme_clear_pgd(&ppd);
+	}
+
+	ppd.vaddr = workarea_start + decrypted_base;
+	ppd.vaddr_end = workarea_end + decrypted_base;
+	sme_clear_pgd(&ppd);
+
+	/* Flush the TLB - no globals so cr3 is enough */
+	native_write_cr3(__native_read_cr3());
+}
+
+void __init sme_enable(struct boot_params *bp)
+{
+	unsigned int eax, ebx, ecx, edx;
+	unsigned long feature_mask;
+	unsigned long me_mask;
+	bool snp_en;
+	u64 msr;
+
+	snp_en = snp_init(bp);
+
+	/* Check for the SME/SEV support leaf */
+	eax = 0x80000000;
+	ecx = 0;
+	native_cpuid(&eax, &ebx, &ecx, &edx);
+	if (eax < 0x8000001f)
+		return;
+
+#define AMD_SME_BIT	BIT(0)
+#define AMD_SEV_BIT	BIT(1)
+
+	/*
+	 * Check for the SME/SEV feature:
+	 *   CPUID Fn8000_001F[EAX]
+	 *   - Bit 0 - Secure Memory Encryption support
+	 *   - Bit 1 - Secure Encrypted Virtualization support
+	 *   CPUID Fn8000_001F[EBX]
+	 *   - Bits 5:0 - Pagetable bit position used to indicate encryption
+	 */
+	eax = 0x8000001f;
+	ecx = 0;
+	native_cpuid(&eax, &ebx, &ecx, &edx);
+	/* Check whether SEV or SME is supported */
+	if (!(eax & (AMD_SEV_BIT | AMD_SME_BIT)))
+		return;
+
+	me_mask = 1UL << (ebx & 0x3f);
+	sev_snp_needs_sfw = !(ebx & BIT(31));
+
+	/* Check the SEV MSR whether SEV or SME is enabled */
+	sev_status = msr = native_rdmsrq(MSR_AMD64_SEV);
+	feature_mask = (msr & MSR_AMD64_SEV_ENABLED) ? AMD_SEV_BIT : AMD_SME_BIT;
+
+	/*
+	 * Any discrepancies between the presence of a CC blob and SNP
+	 * enablement abort the guest.
+	 */
+	if (snp_en ^ !!(msr & MSR_AMD64_SEV_SNP_ENABLED))
+		sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
+
+	/* Check if memory encryption is enabled */
+	if (feature_mask == AMD_SME_BIT) {
+		if (!(bp->hdr.xloadflags & XLF_MEM_ENCRYPTION))
+			return;
+
+		/*
+		 * No SME if Hypervisor bit is set. This check is here to
+		 * prevent a guest from trying to enable SME. For running as a
+		 * KVM guest the MSR_AMD64_SYSCFG will be sufficient, but there
+		 * might be other hypervisors which emulate that MSR as non-zero
+		 * or even pass it through to the guest.
+		 * A malicious hypervisor can still trick a guest into this
+		 * path, but there is no way to protect against that.
+		 */
+		eax = 1;
+		ecx = 0;
+		native_cpuid(&eax, &ebx, &ecx, &edx);
+		if (ecx & BIT(31))
+			return;
+
+		/* For SME, check the SYSCFG MSR */
+		msr = native_rdmsrq(MSR_AMD64_SYSCFG);
+		if (!(msr & MSR_AMD64_SYSCFG_MEM_ENCRYPT))
+			return;
+	}
+
+	sme_me_mask	= me_mask;
+	physical_mask	&= ~me_mask;
+	cc_vendor	= CC_VENDOR_AMD;
+	cc_set_mask(me_mask);
+}
+
+#ifdef CONFIG_MITIGATION_PAGE_TABLE_ISOLATION
+/* Local version for startup code, which never operates on user page tables */
+pgd_t __pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd)
+{
+	return pgd;
+}
+#endif

linux-7.2.3/arch/x86/boot/string.c

@@ -0,0 +1,357 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Very basic string functions
+ */
+
+#include <linux/types.h>
+#include <linux/compiler.h>
+#include <linux/errno.h>
+#include <linux/limits.h>
+#include <asm/asm.h>
+#include "ctype.h"
+#include "string.h"
+
+#define KSTRTOX_OVERFLOW       (1U << 31)
+
+/*
+ * Undef these macros so that the functions that we provide
+ * here will have the correct names regardless of how string.h
+ * may have chosen to #define them.
+ */
+#undef memcpy
+#undef memset
+#undef memcmp
+
+int memcmp(const void *s1, const void *s2, size_t len)
+{
+	bool diff;
+
+	/*
+	 * Make sure ZF is properly set in the len==0 case because in it,
+	 * RCX==0 and the REPE; CMPSB won't get executed.
+	 */
+	asm volatile("test %3, %3\n\t"
+		     "repe cmpsb"
+		     : "=@ccnz" (diff), "+D" (s1), "+S" (s2), "+c" (len)
+		     : : "cc", "memory");
+	return diff;
+}
+
+/*
+ * Clang may lower `memcmp == 0` to `bcmp == 0`.
+ */
+int bcmp(const void *s1, const void *s2, size_t len)
+{
+	return memcmp(s1, s2, len);
+}
+
+int strcmp(const char *str1, const char *str2)
+{
+	const unsigned char *s1 = (const unsigned char *)str1;
+	const unsigned char *s2 = (const unsigned char *)str2;
+	int delta;
+
+	while (*s1 || *s2) {
+		delta = *s1 - *s2;
+		if (delta)
+			return delta;
+		s1++;
+		s2++;
+	}
+	return 0;
+}
+
+int strncmp(const char *cs, const char *ct, size_t count)
+{
+	unsigned char c1, c2;
+
+	while (count) {
+		c1 = *cs++;
+		c2 = *ct++;
+		if (c1 != c2)
+			return c1 < c2 ? -1 : 1;
+		if (!c1)
+			break;
+		count--;
+	}
+	return 0;
+}
+
+size_t strnlen(const char *s, size_t maxlen)
+{
+	const char *es = s;
+	while (*es && maxlen) {
+		es++;
+		maxlen--;
+	}
+
+	return (es - s);
+}
+
+/* Works only for digits and letters, but small and fast */
+#define TOLOWER(x) ((x) | 0x20)
+
+static unsigned int simple_guess_base(const char *cp)
+{
+	if (cp[0] == '0') {
+		if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2]))
+			return 16;
+		else
+			return 8;
+	} else {
+		return 10;
+	}
+}
+
+/**
+ * simple_strtoull - convert a string to an unsigned long long
+ * @cp: The start of the string
+ * @endp: A pointer to the end of the parsed string will be placed here
+ * @base: The number base to use
+ */
+unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
+{
+	unsigned long long result = 0;
+
+	if (!base)
+		base = simple_guess_base(cp);
+
+	if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
+		cp += 2;
+
+	while (isxdigit(*cp)) {
+		unsigned int value;
+
+		value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
+		if (value >= base)
+			break;
+		result = result * base + value;
+		cp++;
+	}
+	if (endp)
+		*endp = (char *)cp;
+
+	return result;
+}
+
+long simple_strtol(const char *cp, char **endp, unsigned int base)
+{
+	if (*cp == '-')
+		return -simple_strtoull(cp + 1, endp, base);
+
+	return simple_strtoull(cp, endp, base);
+}
+
+/**
+ * strlen - Find the length of a string
+ * @s: The string to be sized
+ */
+size_t strlen(const char *s)
+{
+	const char *sc;
+
+	for (sc = s; *sc != '\0'; ++sc)
+		/* nothing */;
+	return sc - s;
+}
+
+/**
+ * strstr - Find the first substring in a %NUL terminated string
+ * @s1: The string to be searched
+ * @s2: The string to search for
+ */
+char *strstr(const char *s1, const char *s2)
+{
+	size_t l1, l2;
+
+	l2 = strlen(s2);
+	if (!l2)
+		return (char *)s1;
+	l1 = strlen(s1);
+	while (l1 >= l2) {
+		l1--;
+		if (!memcmp(s1, s2, l2))
+			return (char *)s1;
+		s1++;
+	}
+	return NULL;
+}
+
+/**
+ * strchr - Find the first occurrence of the character c in the string s.
+ * @s: the string to be searched
+ * @c: the character to search for
+ */
+char *strchr(const char *s, int c)
+{
+	while (*s != (char)c)
+		if (*s++ == '\0')
+			return NULL;
+	return (char *)s;
+}
+
+static inline u64 __div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
+{
+	union {
+		u64 v64;
+		u32 v32[2];
+	} d = { dividend };
+	u32 upper;
+
+	upper = d.v32[1];
+	d.v32[1] = 0;
+	if (upper >= divisor) {
+		d.v32[1] = upper / divisor;
+		upper %= divisor;
+	}
+	asm ("divl %2" : "=a" (d.v32[0]), "=d" (*remainder) :
+		"rm" (divisor), "0" (d.v32[0]), "1" (upper));
+	return d.v64;
+}
+
+static inline u64 __div_u64(u64 dividend, u32 divisor)
+{
+	u32 remainder;
+
+	return __div_u64_rem(dividend, divisor, &remainder);
+}
+
+static inline char _tolower(const char c)
+{
+	return c | 0x20;
+}
+
+static const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)
+{
+	if (*base == 0) {
+		if (s[0] == '0') {
+			if (_tolower(s[1]) == 'x' && isxdigit(s[2]))
+				*base = 16;
+			else
+				*base = 8;
+		} else
+			*base = 10;
+	}
+	if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x')
+		s += 2;
+	return s;
+}
+
+/*
+ * Convert non-negative integer string representation in explicitly given radix
+ * to an integer.
+ * Return number of characters consumed maybe or-ed with overflow bit.
+ * If overflow occurs, result integer (incorrect) is still returned.
+ *
+ * Don't you dare use this function.
+ */
+static unsigned int _parse_integer(const char *s,
+				   unsigned int base,
+				   unsigned long long *p)
+{
+	unsigned long long res;
+	unsigned int rv;
+
+	res = 0;
+	rv = 0;
+	while (1) {
+		unsigned int c = *s;
+		unsigned int lc = c | 0x20; /* don't tolower() this line */
+		unsigned int val;
+
+		if ('0' <= c && c <= '9')
+			val = c - '0';
+		else if ('a' <= lc && lc <= 'f')
+			val = lc - 'a' + 10;
+		else
+			break;
+
+		if (val >= base)
+			break;
+		/*
+		 * Check for overflow only if we are within range of
+		 * it in the max base we support (16)
+		 */
+		if (unlikely(res & (~0ull << 60))) {
+			if (res > __div_u64(ULLONG_MAX - val, base))
+				rv |= KSTRTOX_OVERFLOW;
+		}
+		res = res * base + val;
+		rv++;
+		s++;
+	}
+	*p = res;
+	return rv;
+}
+
+static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res)
+{
+	unsigned long long _res;
+	unsigned int rv;
+
+	if (s[0] == '+')
+		s++;
+
+	s = _parse_integer_fixup_radix(s, &base);
+	rv = _parse_integer(s, base, &_res);
+	if (rv & KSTRTOX_OVERFLOW)
+		return -ERANGE;
+	if (rv == 0)
+		return -EINVAL;
+	s += rv;
+	if (*s == '\n')
+		s++;
+	if (*s)
+		return -EINVAL;
+	*res = _res;
+	return 0;
+}
+
+static int _kstrtoul(const char *s, unsigned int base, unsigned long *res)
+{
+	unsigned long long tmp;
+	int rv;
+
+	rv = _kstrtoull(s, base, &tmp);
+	if (rv < 0)
+		return rv;
+	if (tmp != (unsigned long)tmp)
+		return -ERANGE;
+	*res = tmp;
+	return 0;
+}
+
+/**
+ * boot_kstrtoul - convert a string to an unsigned long
+ * @s: The start of the string. The string must be null-terminated, and may also
+ *  include a single newline before its terminating null. The first character
+ *  may also be a plus sign, but not a minus sign.
+ * @base: The number base to use. The maximum supported base is 16. If base is
+ *  given as 0, then the base of the string is automatically detected with the
+ *  conventional semantics - If it begins with 0x the number will be parsed as a
+ *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
+ *  parsed as an octal number. Otherwise it will be parsed as a decimal.
+ * @res: Where to write the result of the conversion on success.
+ *
+ * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
+ * Used as a replacement for the simple_strtoull.
+ */
+int boot_kstrtoul(const char *s, unsigned int base, unsigned long *res)
+{
+	/*
+	 * We want to shortcut function call, but
+	 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
+	 */
+	if (sizeof(unsigned long) == sizeof(unsigned long long) &&
+	    __alignof__(unsigned long) == __alignof__(unsigned long long))
+		return _kstrtoull(s, base, (unsigned long long *)res);
+	else
+		return _kstrtoul(s, base, res);
+}

linux-7.2.3/arch/x86/boot/string.h

@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BOOT_STRING_H
+#define BOOT_STRING_H
+
+/* Undef any of these macros coming from string_32.h. */
+#undef memcpy
+#undef memset
+#undef memcmp
+
+void *memcpy(void *dst, const void *src, size_t len);
+void *memmove(void *dst, const void *src, size_t len);
+void *memset(void *dst, int c, size_t len);
+int memcmp(const void *s1, const void *s2, size_t len);
+int bcmp(const void *s1, const void *s2, size_t len);
+
+/* Access builtin version by default. */
+#define memcpy(d,s,l) __builtin_memcpy(d,s,l)
+#define memset(d,c,l) __builtin_memset(d,c,l)
+#define memcmp	__builtin_memcmp
+
+extern int strcmp(const char *str1, const char *str2);
+extern int strncmp(const char *cs, const char *ct, size_t count);
+extern size_t strlen(const char *s);
+extern char *strstr(const char *s1, const char *s2);
+extern char *strchr(const char *s, int c);
+extern size_t strnlen(const char *s, size_t maxlen);
+extern unsigned long long simple_strtoull(const char *cp, char **endp,
+					  unsigned int base);
+long simple_strtol(const char *cp, char **endp, unsigned int base);
+
+int boot_kstrtoul(const char *s, unsigned int base, unsigned long *res);
+#endif /* BOOT_STRING_H */

linux-7.2.3/arch/x86/boot/tty.c

@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *   Copyright 2009 Intel Corporation; author H. Peter Anvin
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Very simple screen and serial I/O
+ */
+
+#include "boot.h"
+
+int early_serial_base;
+
+#define XMTRDY          0x20
+
+#define TXR             0       /*  Transmit register (WRITE) */
+#define LSR             5       /*  Line Status               */
+
+/*
+ * These functions are in .inittext so they can be used to signal
+ * error during initialization.
+ */
+
+static void __section(".inittext") serial_putchar(int ch)
+{
+	unsigned timeout = 0xffff;
+
+	while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout)
+		cpu_relax();
+
+	outb(ch, early_serial_base + TXR);
+}
+
+static void __section(".inittext") bios_putchar(int ch)
+{
+	struct biosregs ireg;
+
+	initregs(&ireg);
+	ireg.bx = 0x0007;
+	ireg.cx = 0x0001;
+	ireg.ah = 0x0e;
+	ireg.al = ch;
+	intcall(0x10, &ireg, NULL);
+}
+
+void __section(".inittext") putchar(int ch)
+{
+	if (ch == '\n')
+		putchar('\r');	/* \n -> \r\n */
+
+	bios_putchar(ch);
+
+	if (early_serial_base != 0)
+		serial_putchar(ch);
+}
+
+void __section(".inittext") puts(const char *str)
+{
+	while (*str)
+		putchar(*str++);
+}
+
+/*
+ * Read the CMOS clock through the BIOS, and return the
+ * seconds in BCD.
+ */
+
+static u8 gettime(void)
+{
+	struct biosregs ireg, oreg;
+
+	initregs(&ireg);
+	ireg.ah = 0x02;
+	intcall(0x1a, &ireg, &oreg);
+
+	return oreg.dh;
+}
+
+/*
+ * Read from the keyboard
+ */
+int getchar(void)
+{
+	struct biosregs ireg, oreg;
+
+	initregs(&ireg);
+	/* ireg.ah = 0x00; */
+	intcall(0x16, &ireg, &oreg);
+
+	return oreg.al;
+}
+
+static int kbd_pending(void)
+{
+	struct biosregs ireg, oreg;
+
+	initregs(&ireg);
+	ireg.ah = 0x01;
+	intcall(0x16, &ireg, &oreg);
+
+	return !(oreg.eflags & X86_EFLAGS_ZF);
+}
+
+void kbd_flush(void)
+{
+	for (;;) {
+		if (!kbd_pending())
+			break;
+		getchar();
+	}
+}
+
+int getchar_timeout(void)
+{
+	int cnt = 30;
+	int t0, t1;
+
+	t0 = gettime();
+
+	while (cnt) {
+		if (kbd_pending())
+			return getchar();
+
+		t1 = gettime();
+		if (t0 != t1) {
+			cnt--;
+			t0 = t1;
+		}
+	}
+
+	return 0;		/* Timeout! */
+}
+

linux-7.2.3/arch/x86/boot/version.c

@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Kernel version string
+ */
+
+#include "boot.h"
+#include <generated/utsversion.h>
+#include <generated/utsrelease.h>
+#include <generated/compile.h>
+
+const char kernel_version[] =
+	UTS_RELEASE " (" LINUX_COMPILE_BY "@" LINUX_COMPILE_HOST ") "
+	UTS_VERSION;

linux-7.2.3/arch/x86/boot/vesa.h

@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* ----------------------------------------------------------------------- *
+ *
+ *   Copyright 1999-2007 H. Peter Anvin - All Rights Reserved
+ *
+ * ----------------------------------------------------------------------- */
+
+#ifndef BOOT_VESA_H
+#define BOOT_VESA_H
+
+typedef struct {
+	u16 off, seg;
+} far_ptr;
+
+/* VESA General Information table */
+struct vesa_general_info {
+	u32 signature;		/* 0 Magic number = "VESA" */
+	u16 version;		/* 4 */
+	far_ptr vendor_string;	/* 6 */
+	u32 capabilities;	/* 10 */
+	far_ptr video_mode_ptr;	/* 14 */
+	u16 total_memory;	/* 18 */
+
+	u8 reserved[236];	/* 20 */
+} __attribute__ ((packed));
+
+#define VESA_MAGIC ('V' + ('E' << 8) + ('S' << 16) + ('A' << 24))
+
+struct vesa_mode_info {
+	u16 mode_attr;		/* 0 */
+	u8 win_attr[2];		/* 2 */
+	u16 win_grain;		/* 4 */
+	u16 win_size;		/* 6 */
+	u16 win_seg[2];		/* 8 */
+	far_ptr win_scheme;	/* 12 */
+	u16 logical_scan;	/* 16 */
+
+	u16 h_res;		/* 18 */
+	u16 v_res;		/* 20 */
+	u8 char_width;		/* 22 */
+	u8 char_height;		/* 23 */
+	u8 memory_planes;	/* 24 */
+	u8 bpp;			/* 25 */
+	u8 banks;		/* 26 */
+	u8 memory_layout;	/* 27 */
+	u8 bank_size;		/* 28 */
+	u8 image_planes;	/* 29 */
+	u8 page_function;	/* 30 */
+
+	u8 rmask;		/* 31 */
+	u8 rpos;		/* 32 */
+	u8 gmask;		/* 33 */
+	u8 gpos;		/* 34 */
+	u8 bmask;		/* 35 */
+	u8 bpos;		/* 36 */
+	u8 resv_mask;		/* 37 */
+	u8 resv_pos;		/* 38 */
+	u8 dcm_info;		/* 39 */
+
+	u32 lfb_ptr;		/* 40 Linear frame buffer address */
+	u32 offscreen_ptr;	/* 44 Offscreen memory address */
+	u16 offscreen_size;	/* 48 */
+
+	u8 reserved[206];	/* 50 */
+} __attribute__ ((packed));
+
+#endif				/* LIB_SYS_VESA_H */

linux-7.2.3/arch/x86/boot/video-bios.c

@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *   Copyright 2009 Intel Corporation; author H. Peter Anvin
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Standard video BIOS modes
+ *
+ * We have two options for this; silent and scanned.
+ */
+
+#include "boot.h"
+#include "video.h"
+
+static __videocard video_bios;
+
+/* Set a conventional BIOS mode */
+static int set_bios_mode(u8 mode);
+
+static int bios_set_mode(struct mode_info *mi)
+{
+	return set_bios_mode(mi->mode - VIDEO_FIRST_BIOS);
+}
+
+static int set_bios_mode(u8 mode)
+{
+	struct biosregs ireg, oreg;
+	u8 new_mode;
+
+	initregs(&ireg);
+	ireg.al = mode;		/* AH=0x00 Set Video Mode */
+	intcall(0x10, &ireg, NULL);
+
+	ireg.ah = 0x0f;		/* Get Current Video Mode */
+	intcall(0x10, &ireg, &oreg);
+
+	do_restore = 1;		/* Assume video contents were lost */
+
+	/* Not all BIOSes are clean with the top bit */
+	new_mode = oreg.al & 0x7f;
+
+	if (new_mode == mode)
+		return 0;	/* Mode change OK */
+
+#ifndef _WAKEUP
+	if (new_mode != boot_params.screen_info.orig_video_mode) {
+		/* Mode setting failed, but we didn't end up where we
+		   started.  That's bad.  Try to revert to the original
+		   video mode. */
+		ireg.ax = boot_params.screen_info.orig_video_mode;
+		intcall(0x10, &ireg, NULL);
+	}
+#endif
+	return -1;
+}
+
+static int bios_probe(void)
+{
+	u8 mode;
+#ifdef _WAKEUP
+	u8 saved_mode = 0x03;
+#else
+	u8 saved_mode = boot_params.screen_info.orig_video_mode;
+#endif
+	u16 crtc;
+	struct mode_info *mi;
+	int nmodes = 0;
+
+	if (adapter != ADAPTER_EGA && adapter != ADAPTER_VGA)
+		return 0;
+
+	set_fs(0);
+	crtc = vga_crtc();
+
+	video_bios.modes = GET_HEAP(struct mode_info, 0);
+
+	for (mode = 0x14; mode <= 0x7f; mode++) {
+		if (!heap_free(sizeof(struct mode_info)))
+			break;
+
+		if (mode_defined(VIDEO_FIRST_BIOS+mode))
+			continue;
+
+		if (set_bios_mode(mode))
+			continue;
+
+		/* Try to verify that it's a text mode. */
+
+		/* Attribute Controller: make graphics controller disabled */
+		if (in_idx(0x3c0, 0x10) & 0x01)
+			continue;
+
+		/* Graphics Controller: verify Alpha addressing enabled */
+		if (in_idx(0x3ce, 0x06) & 0x01)
+			continue;
+
+		/* CRTC cursor location low should be zero(?) */
+		if (in_idx(crtc, 0x0f))
+			continue;
+
+		mi = GET_HEAP(struct mode_info, 1);
+		mi->mode = VIDEO_FIRST_BIOS+mode;
+		mi->depth = 0;	/* text */
+		mi->x = rdfs16(0x44a);
+		mi->y = rdfs8(0x484)+1;
+		nmodes++;
+	}
+
+	set_bios_mode(saved_mode);
+
+	return nmodes;
+}
+
+static __videocard video_bios =
+{
+	.card_name	= "BIOS",
+	.probe		= bios_probe,
+	.set_mode	= bios_set_mode,
+	.unsafe		= 1,
+	.xmode_first	= VIDEO_FIRST_BIOS,
+	.xmode_n	= 0x80,
+};

linux-7.2.3/arch/x86/boot/video-mode.c

@@ -0,0 +1,171 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007-2008 rPath, Inc. - All Rights Reserved
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * arch/i386/boot/video-mode.c
+ *
+ * Set the video mode.  This is separated out into a different
+ * file in order to be shared with the ACPI wakeup code.
+ */
+
+#include "boot.h"
+#include "video.h"
+#include "vesa.h"
+
+#include <uapi/asm/boot.h>
+
+/*
+ * Common variables
+ */
+int adapter;		/* 0=CGA/MDA/HGC, 1=EGA, 2=VGA+ */
+int force_x, force_y;	/* Don't query the BIOS for cols/rows */
+int do_restore;		/* Screen contents changed during mode flip */
+int graphic_mode;	/* Graphic mode with linear frame buffer */
+
+/* Probe the video drivers and have them generate their mode lists. */
+void probe_cards(int unsafe)
+{
+	struct card_info *card;
+	static u8 probed[2];
+
+	if (probed[unsafe])
+		return;
+
+	probed[unsafe] = 1;
+
+	for (card = video_cards; card < video_cards_end; card++) {
+		if (card->unsafe == unsafe) {
+			if (card->probe)
+				card->nmodes = card->probe();
+			else
+				card->nmodes = 0;
+		}
+	}
+}
+
+/* Test if a mode is defined */
+int mode_defined(u16 mode)
+{
+	struct card_info *card;
+	struct mode_info *mi;
+	int i;
+
+	for (card = video_cards; card < video_cards_end; card++) {
+		mi = card->modes;
+		for (i = 0; i < card->nmodes; i++, mi++) {
+			if (mi->mode == mode)
+				return 1;
+		}
+	}
+
+	return 0;
+}
+
+/* Set mode (without recalc) */
+static int raw_set_mode(u16 mode, u16 *real_mode)
+{
+	int nmode, i;
+	struct card_info *card;
+	struct mode_info *mi;
+
+	/* Drop the recalc bit if set */
+	mode &= ~VIDEO_RECALC;
+
+	/* Scan for mode based on fixed ID, position, or resolution */
+	nmode = 0;
+	for (card = video_cards; card < video_cards_end; card++) {
+		mi = card->modes;
+		for (i = 0; i < card->nmodes; i++, mi++) {
+			int visible = mi->x || mi->y;
+
+			if ((mode == nmode && visible) ||
+			    mode == mi->mode ||
+			    mode == (mi->y << 8)+mi->x) {
+				*real_mode = mi->mode;
+				return card->set_mode(mi);
+			}
+
+			if (visible)
+				nmode++;
+		}
+	}
+
+	/* Nothing found?  Is it an "exceptional" (unprobed) mode? */
+	for (card = video_cards; card < video_cards_end; card++) {
+		if (mode >= card->xmode_first &&
+		    mode < card->xmode_first+card->xmode_n) {
+			struct mode_info mix;
+			*real_mode = mix.mode = mode;
+			mix.x = mix.y = 0;
+			return card->set_mode(&mix);
+		}
+	}
+
+	/* Otherwise, failure... */
+	return -1;
+}
+
+/*
+ * Recalculate the vertical video cutoff (hack!)
+ */
+static void vga_recalc_vertical(void)
+{
+	unsigned int font_size, rows;
+	u16 crtc;
+	u8 pt, ov;
+
+	set_fs(0);
+	font_size = rdfs8(0x485); /* BIOS: font size (pixels) */
+	rows = force_y ? force_y : rdfs8(0x484)+1; /* Text rows */
+
+	rows *= font_size;	/* Visible scan lines */
+	rows--;			/* ... minus one */
+
+	crtc = vga_crtc();
+
+	pt = in_idx(crtc, 0x11);
+	pt &= ~0x80;		/* Unlock CR0-7 */
+	out_idx(pt, crtc, 0x11);
+
+	out_idx((u8)rows, crtc, 0x12); /* Lower height register */
+
+	ov = in_idx(crtc, 0x07); /* Overflow register */
+	ov &= 0xbd;
+	ov |= (rows >> (8-1)) & 0x02;
+	ov |= (rows >> (9-6)) & 0x40;
+	out_idx(ov, crtc, 0x07);
+}
+
+/* Set mode (with recalc if specified) */
+int set_mode(u16 mode)
+{
+	int rv;
+	u16 real_mode;
+
+	/* Very special mode numbers... */
+	if (mode == VIDEO_CURRENT_MODE)
+		return 0;	/* Nothing to do... */
+	else if (mode == NORMAL_VGA)
+		mode = VIDEO_80x25;
+	else if (mode == EXTENDED_VGA)
+		mode = VIDEO_8POINT;
+
+	rv = raw_set_mode(mode, &real_mode);
+	if (rv)
+		return rv;
+
+	if (mode & VIDEO_RECALC)
+		vga_recalc_vertical();
+
+	/* Save the canonical mode number for the kernel, not
+	   an alias, size specification or menu position */
+#ifndef _WAKEUP
+	boot_params.hdr.vid_mode = real_mode;
+#endif
+	return 0;
+}

linux-7.2.3/arch/x86/boot/video-vesa.c

@@ -0,0 +1,279 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *   Copyright 2009 Intel Corporation; author H. Peter Anvin
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * VESA text modes
+ */
+
+#include "boot.h"
+#include "video.h"
+#include "vesa.h"
+#include "string.h"
+
+/* VESA information */
+static struct vesa_general_info vginfo;
+static struct vesa_mode_info vminfo;
+
+static __videocard video_vesa;
+
+#ifndef _WAKEUP
+static void vesa_store_mode_params_graphics(void);
+#else /* _WAKEUP */
+static inline void vesa_store_mode_params_graphics(void) {}
+#endif /* _WAKEUP */
+
+static int vesa_probe(void)
+{
+	struct biosregs ireg, oreg;
+	u16 mode;
+	addr_t mode_ptr;
+	struct mode_info *mi;
+	int nmodes = 0;
+
+	video_vesa.modes = GET_HEAP(struct mode_info, 0);
+
+	initregs(&ireg);
+	ireg.ax = 0x4f00;
+	ireg.di = (size_t)&vginfo;
+	intcall(0x10, &ireg, &oreg);
+
+	if (oreg.ax != 0x004f ||
+	    vginfo.signature != VESA_MAGIC ||
+	    vginfo.version < 0x0102)
+		return 0;	/* Not present */
+
+	set_fs(vginfo.video_mode_ptr.seg);
+	mode_ptr = vginfo.video_mode_ptr.off;
+
+	while ((mode = rdfs16(mode_ptr)) != 0xffff) {
+		mode_ptr += 2;
+
+		if (!heap_free(sizeof(struct mode_info)))
+			break;	/* Heap full, can't save mode info */
+
+		if (mode & ~0x1ff)
+			continue;
+
+		memset(&vminfo, 0, sizeof(vminfo)); /* Just in case... */
+
+		ireg.ax = 0x4f01;
+		ireg.cx = mode;
+		ireg.di = (size_t)&vminfo;
+		intcall(0x10, &ireg, &oreg);
+
+		if (oreg.ax != 0x004f)
+			continue;
+
+		if ((vminfo.mode_attr & 0x15) == 0x05) {
+			/* Text Mode, TTY BIOS supported,
+			   supported by hardware */
+			mi = GET_HEAP(struct mode_info, 1);
+			mi->mode  = mode + VIDEO_FIRST_VESA;
+			mi->depth = 0; /* text */
+			mi->x     = vminfo.h_res;
+			mi->y     = vminfo.v_res;
+			nmodes++;
+		} else if ((vminfo.mode_attr & 0x99) == 0x99 &&
+			   (vminfo.memory_layout == 4 ||
+			    vminfo.memory_layout == 6) &&
+			   vminfo.memory_planes == 1) {
+#ifdef CONFIG_BOOT_VESA_SUPPORT
+			/* Graphics mode, color, linear frame buffer
+			   supported.  Only register the mode if
+			   if framebuffer is configured, however,
+			   otherwise the user will be left without a screen. */
+			mi = GET_HEAP(struct mode_info, 1);
+			mi->mode = mode + VIDEO_FIRST_VESA;
+			mi->depth = vminfo.bpp;
+			mi->x = vminfo.h_res;
+			mi->y = vminfo.v_res;
+			nmodes++;
+#endif
+		}
+	}
+
+	return nmodes;
+}
+
+static int vesa_set_mode(struct mode_info *mode)
+{
+	struct biosregs ireg, oreg;
+	int is_graphic;
+	u16 vesa_mode = mode->mode - VIDEO_FIRST_VESA;
+
+	memset(&vminfo, 0, sizeof(vminfo)); /* Just in case... */
+
+	initregs(&ireg);
+	ireg.ax = 0x4f01;
+	ireg.cx = vesa_mode;
+	ireg.di = (size_t)&vminfo;
+	intcall(0x10, &ireg, &oreg);
+
+	if (oreg.ax != 0x004f)
+		return -1;
+
+	if ((vminfo.mode_attr & 0x15) == 0x05) {
+		/* It's a supported text mode */
+		is_graphic = 0;
+#ifdef CONFIG_BOOT_VESA_SUPPORT
+	} else if ((vminfo.mode_attr & 0x99) == 0x99) {
+		/* It's a graphics mode with linear frame buffer */
+		is_graphic = 1;
+		vesa_mode |= 0x4000; /* Request linear frame buffer */
+#endif
+	} else {
+		return -1;	/* Invalid mode */
+	}
+
+
+	initregs(&ireg);
+	ireg.ax = 0x4f02;
+	ireg.bx = vesa_mode;
+	intcall(0x10, &ireg, &oreg);
+
+	if (oreg.ax != 0x004f)
+		return -1;
+
+	graphic_mode = is_graphic;
+	if (!is_graphic) {
+		/* Text mode */
+		force_x = mode->x;
+		force_y = mode->y;
+		do_restore = 1;
+	} else {
+		/* Graphics mode */
+		vesa_store_mode_params_graphics();
+	}
+
+	return 0;
+}
+
+
+#ifndef _WAKEUP
+
+/* Switch DAC to 8-bit mode */
+static void vesa_dac_set_8bits(void)
+{
+	struct biosregs ireg, oreg;
+	u8 dac_size = 6;
+
+	/* If possible, switch the DAC to 8-bit mode */
+	if (vginfo.capabilities & 1) {
+		initregs(&ireg);
+		ireg.ax = 0x4f08;
+		ireg.bh = 0x08;
+		intcall(0x10, &ireg, &oreg);
+		if (oreg.ax == 0x004f)
+			dac_size = oreg.bh;
+	}
+
+	/* Set the color sizes to the DAC size, and offsets to 0 */
+	boot_params.screen_info.red_size   = dac_size;
+	boot_params.screen_info.green_size = dac_size;
+	boot_params.screen_info.blue_size  = dac_size;
+	boot_params.screen_info.rsvd_size  = dac_size;
+
+	boot_params.screen_info.red_pos    = 0;
+	boot_params.screen_info.green_pos  = 0;
+	boot_params.screen_info.blue_pos   = 0;
+	boot_params.screen_info.rsvd_pos   = 0;
+}
+
+/* Save the VESA protected mode info */
+static void vesa_store_pm_info(void)
+{
+	struct biosregs ireg, oreg;
+
+	initregs(&ireg);
+	ireg.ax = 0x4f0a;
+	intcall(0x10, &ireg, &oreg);
+
+	if (oreg.ax != 0x004f)
+		return;
+
+	boot_params.screen_info.vesapm_seg = oreg.es;
+	boot_params.screen_info.vesapm_off = oreg.di;
+}
+
+/*
+ * Save video mode parameters for graphics mode
+ */
+static void vesa_store_mode_params_graphics(void)
+{
+	/* Tell the kernel we're in VESA graphics mode */
+	boot_params.screen_info.orig_video_isVGA = VIDEO_TYPE_VLFB;
+
+	/* Mode parameters */
+	boot_params.screen_info.vesa_attributes = vminfo.mode_attr;
+	boot_params.screen_info.lfb_linelength = vminfo.logical_scan;
+	boot_params.screen_info.lfb_width = vminfo.h_res;
+	boot_params.screen_info.lfb_height = vminfo.v_res;
+	boot_params.screen_info.lfb_depth = vminfo.bpp;
+	boot_params.screen_info.pages = vminfo.image_planes;
+	boot_params.screen_info.lfb_base = vminfo.lfb_ptr;
+	memcpy(&boot_params.screen_info.red_size,
+	       &vminfo.rmask, 8);
+
+	/* General parameters */
+	boot_params.screen_info.lfb_size = vginfo.total_memory;
+
+	if (vminfo.bpp <= 8)
+		vesa_dac_set_8bits();
+
+	vesa_store_pm_info();
+}
+
+/*
+ * Save EDID information for the kernel; this is invoked, separately,
+ * after mode-setting.
+ */
+void vesa_store_edid(void)
+{
+#ifdef CONFIG_FIRMWARE_EDID
+	struct biosregs ireg, oreg;
+
+	/* Apparently used as a nonsense token... */
+	memset(&boot_params.edid_info, 0x13, sizeof(boot_params.edid_info));
+
+	if (vginfo.version < 0x0200)
+		return;		/* EDID requires VBE 2.0+ */
+
+	initregs(&ireg);
+	ireg.ax = 0x4f15;		/* VBE DDC */
+	/* ireg.bx = 0x0000; */		/* Report DDC capabilities */
+	/* ireg.cx = 0;	*/		/* Controller 0 */
+	ireg.es = 0;			/* ES:DI must be 0 by spec */
+	intcall(0x10, &ireg, &oreg);
+
+	if (oreg.ax != 0x004f)
+		return;		/* No EDID */
+
+	/* BH = time in seconds to transfer EDD information */
+	/* BL = DDC level supported */
+
+	ireg.ax = 0x4f15;		/* VBE DDC */
+	ireg.bx = 0x0001;		/* Read EDID */
+	/* ireg.cx = 0; */		/* Controller 0 */
+	/* ireg.dx = 0;	*/		/* EDID block number */
+	ireg.es = ds();
+	ireg.di =(size_t)&boot_params.edid_info; /* (ES:)Pointer to block */
+	intcall(0x10, &ireg, &oreg);
+#endif /* CONFIG_FIRMWARE_EDID */
+}
+
+#endif /* not _WAKEUP */
+
+static __videocard video_vesa =
+{
+	.card_name	= "VESA",
+	.probe		= vesa_probe,
+	.set_mode	= vesa_set_mode,
+	.xmode_first	= VIDEO_FIRST_VESA,
+	.xmode_n	= 0x200,
+};

linux-7.2.3/arch/x86/boot/video-vga.c

@@ -0,0 +1,286 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *   Copyright 2009 Intel Corporation; author H. Peter Anvin
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Common all-VGA modes
+ */
+
+#include "boot.h"
+#include "video.h"
+
+static struct mode_info vga_modes[] = {
+	{ VIDEO_80x25,  80, 25, 0 },
+	{ VIDEO_8POINT, 80, 50, 0 },
+	{ VIDEO_80x43,  80, 43, 0 },
+	{ VIDEO_80x28,  80, 28, 0 },
+	{ VIDEO_80x30,  80, 30, 0 },
+	{ VIDEO_80x34,  80, 34, 0 },
+	{ VIDEO_80x60,  80, 60, 0 },
+};
+
+static struct mode_info ega_modes[] = {
+	{ VIDEO_80x25,  80, 25, 0 },
+	{ VIDEO_8POINT, 80, 43, 0 },
+};
+
+static struct mode_info cga_modes[] = {
+	{ VIDEO_80x25,  80, 25, 0 },
+};
+
+static __videocard video_vga;
+
+/* Set basic 80x25 mode */
+static u8 vga_set_basic_mode(void)
+{
+	struct biosregs ireg, oreg;
+	u8 mode;
+
+	initregs(&ireg);
+
+	/* Query current mode */
+	ireg.ax = 0x0f00;
+	intcall(0x10, &ireg, &oreg);
+	mode = oreg.al;
+
+	if (mode != 3 && mode != 7)
+		mode = 3;
+
+	/* Set the mode */
+	ireg.ax = mode;		/* AH=0: set mode */
+	intcall(0x10, &ireg, NULL);
+	do_restore = 1;
+	return mode;
+}
+
+static void vga_set_8font(void)
+{
+	/* Set 8x8 font - 80x43 on EGA, 80x50 on VGA */
+	struct biosregs ireg;
+
+	initregs(&ireg);
+
+	/* Set 8x8 font */
+	ireg.ax = 0x1112;
+	/* ireg.bl = 0; */
+	intcall(0x10, &ireg, NULL);
+
+	/* Use alternate print screen */
+	ireg.ax = 0x1200;
+	ireg.bl = 0x20;
+	intcall(0x10, &ireg, NULL);
+
+	/* Turn off cursor emulation */
+	ireg.ax = 0x1201;
+	ireg.bl = 0x34;
+	intcall(0x10, &ireg, NULL);
+
+	/* Cursor is scan lines 6-7 */
+	ireg.ax = 0x0100;
+	ireg.cx = 0x0607;
+	intcall(0x10, &ireg, NULL);
+}
+
+static void vga_set_14font(void)
+{
+	/* Set 9x14 font - 80x28 on VGA */
+	struct biosregs ireg;
+
+	initregs(&ireg);
+
+	/* Set 9x14 font */
+	ireg.ax = 0x1111;
+	/* ireg.bl = 0; */
+	intcall(0x10, &ireg, NULL);
+
+	/* Turn off cursor emulation */
+	ireg.ax = 0x1201;
+	ireg.bl = 0x34;
+	intcall(0x10, &ireg, NULL);
+
+	/* Cursor is scan lines 11-12 */
+	ireg.ax = 0x0100;
+	ireg.cx = 0x0b0c;
+	intcall(0x10, &ireg, NULL);
+}
+
+static void vga_set_80x43(void)
+{
+	/* Set 80x43 mode on VGA (not EGA) */
+	struct biosregs ireg;
+
+	initregs(&ireg);
+
+	/* Set 350 scans */
+	ireg.ax = 0x1201;
+	ireg.bl = 0x30;
+	intcall(0x10, &ireg, NULL);
+
+	/* Reset video mode */
+	ireg.ax = 0x0003;
+	intcall(0x10, &ireg, NULL);
+
+	vga_set_8font();
+}
+
+/* I/O address of the VGA CRTC */
+u16 vga_crtc(void)
+{
+	return (inb(0x3cc) & 1) ? 0x3d4 : 0x3b4;
+}
+
+static void vga_set_480_scanlines(void)
+{
+	u16 crtc;		/* CRTC base address */
+	u8  csel;		/* CRTC miscellaneous output register */
+
+	crtc = vga_crtc();
+
+	out_idx(0x0c, crtc, 0x11); /* Vertical sync end, unlock CR0-7 */
+	out_idx(0x0b, crtc, 0x06); /* Vertical total */
+	out_idx(0x3e, crtc, 0x07); /* Vertical overflow */
+	out_idx(0xea, crtc, 0x10); /* Vertical sync start */
+	out_idx(0xdf, crtc, 0x12); /* Vertical display end */
+	out_idx(0xe7, crtc, 0x15); /* Vertical blank start */
+	out_idx(0x04, crtc, 0x16); /* Vertical blank end */
+	csel = inb(0x3cc);
+	csel &= 0x0d;
+	csel |= 0xe2;
+	outb(csel, 0x3c2);
+}
+
+static void vga_set_vertical_end(int lines)
+{
+	u16 crtc;		/* CRTC base address */
+	u8  ovfw;		/* CRTC overflow register */
+	int end = lines-1;
+
+	crtc = vga_crtc();
+
+	ovfw = 0x3c | ((end >> (8-1)) & 0x02) | ((end >> (9-6)) & 0x40);
+
+	out_idx(ovfw, crtc, 0x07); /* Vertical overflow */
+	out_idx(end,  crtc, 0x12); /* Vertical display end */
+}
+
+static void vga_set_80x30(void)
+{
+	vga_set_480_scanlines();
+	vga_set_vertical_end(30*16);
+}
+
+static void vga_set_80x34(void)
+{
+	vga_set_480_scanlines();
+	vga_set_14font();
+	vga_set_vertical_end(34*14);
+}
+
+static void vga_set_80x60(void)
+{
+	vga_set_480_scanlines();
+	vga_set_8font();
+	vga_set_vertical_end(60*8);
+}
+
+static int vga_set_mode(struct mode_info *mode)
+{
+	/* Set the basic mode */
+	vga_set_basic_mode();
+
+	/* Override a possibly broken BIOS */
+	force_x = mode->x;
+	force_y = mode->y;
+
+	switch (mode->mode) {
+	case VIDEO_80x25:
+		break;
+	case VIDEO_8POINT:
+		vga_set_8font();
+		break;
+	case VIDEO_80x43:
+		vga_set_80x43();
+		break;
+	case VIDEO_80x28:
+		vga_set_14font();
+		break;
+	case VIDEO_80x30:
+		vga_set_80x30();
+		break;
+	case VIDEO_80x34:
+		vga_set_80x34();
+		break;
+	case VIDEO_80x60:
+		vga_set_80x60();
+		break;
+	}
+
+	return 0;
+}
+
+/*
+ * Note: this probe includes basic information required by all
+ * systems.  It should be executed first, by making sure
+ * video-vga.c is listed first in the Makefile.
+ */
+static int vga_probe(void)
+{
+	static const char *card_name[] = {
+		"CGA/MDA/HGC", "EGA", "VGA"
+	};
+	static struct mode_info *mode_lists[] = {
+		cga_modes,
+		ega_modes,
+		vga_modes,
+	};
+	static int mode_count[] = {
+		ARRAY_SIZE(cga_modes),
+		ARRAY_SIZE(ega_modes),
+		ARRAY_SIZE(vga_modes),
+	};
+
+	struct biosregs ireg, oreg;
+
+	initregs(&ireg);
+
+	ireg.ax = 0x1200;
+	ireg.bl = 0x10;		/* Check EGA/VGA */
+	intcall(0x10, &ireg, &oreg);
+
+#ifndef _WAKEUP
+	boot_params.screen_info.orig_video_ega_bx = oreg.bx;
+#endif
+
+	/* If we have MDA/CGA/HGC then BL will be unchanged at 0x10 */
+	if (oreg.bl != 0x10) {
+		/* EGA/VGA */
+		ireg.ax = 0x1a00;
+		intcall(0x10, &ireg, &oreg);
+
+		if (oreg.al == 0x1a) {
+			adapter = ADAPTER_VGA;
+#ifndef _WAKEUP
+			boot_params.screen_info.orig_video_isVGA = 1;
+#endif
+		} else {
+			adapter = ADAPTER_EGA;
+		}
+	} else {
+		adapter = ADAPTER_CGA;
+	}
+
+	video_vga.modes = mode_lists[adapter];
+	video_vga.card_name = card_name[adapter];
+	return mode_count[adapter];
+}
+
+static __videocard video_vga = {
+	.card_name	= "VGA",
+	.probe		= vga_probe,
+	.set_mode	= vga_set_mode,
+};

linux-7.2.3/arch/x86/boot/video.c

@@ -0,0 +1,343 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *   Copyright 2009 Intel Corporation; author H. Peter Anvin
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Select video mode
+ */
+
+#include <uapi/asm/boot.h>
+
+#include "boot.h"
+#include "video.h"
+#include "vesa.h"
+
+static u16 video_segment;
+
+static void store_cursor_position(void)
+{
+	struct biosregs ireg, oreg;
+
+	initregs(&ireg);
+	ireg.ah = 0x03;
+	intcall(0x10, &ireg, &oreg);
+
+	boot_params.screen_info.orig_x = oreg.dl;
+	boot_params.screen_info.orig_y = oreg.dh;
+
+	if (oreg.ch & 0x20)
+		boot_params.screen_info.flags |= VIDEO_FLAGS_NOCURSOR;
+
+	if ((oreg.ch & 0x1f) > (oreg.cl & 0x1f))
+		boot_params.screen_info.flags |= VIDEO_FLAGS_NOCURSOR;
+}
+
+static void store_video_mode(void)
+{
+	struct biosregs ireg, oreg;
+
+	/* N.B.: the saving of the video page here is a bit silly,
+	   since we pretty much assume page 0 everywhere. */
+	initregs(&ireg);
+	ireg.ah = 0x0f;
+	intcall(0x10, &ireg, &oreg);
+
+	/* Not all BIOSes are clean with respect to the top bit */
+	boot_params.screen_info.orig_video_mode = oreg.al & 0x7f;
+	boot_params.screen_info.orig_video_page = oreg.bh;
+}
+
+/*
+ * Store the video mode parameters for later usage by the kernel.
+ * This is done by asking the BIOS except for the rows/columns
+ * parameters in the default 80x25 mode -- these are set directly,
+ * because some very obscure BIOSes supply insane values.
+ */
+static void store_mode_params(void)
+{
+	u16 font_size;
+	int x, y;
+
+	/* For graphics mode, it is up to the mode-setting driver
+	   (currently only video-vesa.c) to store the parameters */
+	if (graphic_mode)
+		return;
+
+	store_cursor_position();
+	store_video_mode();
+
+	if (boot_params.screen_info.orig_video_mode == 0x07) {
+		/* MDA, HGC, or VGA in monochrome mode */
+		video_segment = 0xb000;
+	} else {
+		/* CGA, EGA, VGA and so forth */
+		video_segment = 0xb800;
+	}
+
+	set_fs(0);
+	font_size = rdfs16(0x485); /* Font size, BIOS area */
+	boot_params.screen_info.orig_video_points = font_size;
+
+	x = rdfs16(0x44a);
+	y = (adapter == ADAPTER_CGA) ? 25 : rdfs8(0x484)+1;
+
+	if (force_x)
+		x = force_x;
+	if (force_y)
+		y = force_y;
+
+	boot_params.screen_info.orig_video_cols  = x;
+	boot_params.screen_info.orig_video_lines = y;
+}
+
+static unsigned int get_entry(void)
+{
+	char entry_buf[4];
+	int i, len = 0;
+	int key;
+	unsigned int v;
+
+	do {
+		key = getchar();
+
+		if (key == '\b') {
+			if (len > 0) {
+				puts("\b \b");
+				len--;
+			}
+		} else if ((key >= '0' && key <= '9') ||
+			   (key >= 'A' && key <= 'Z') ||
+			   (key >= 'a' && key <= 'z')) {
+			if (len < sizeof(entry_buf)) {
+				entry_buf[len++] = key;
+				putchar(key);
+			}
+		}
+	} while (key != '\r');
+	putchar('\n');
+
+	if (len == 0)
+		return VIDEO_CURRENT_MODE; /* Default */
+
+	v = 0;
+	for (i = 0; i < len; i++) {
+		v <<= 4;
+		key = entry_buf[i] | 0x20;
+		v += (key > '9') ? key-'a'+10 : key-'0';
+	}
+
+	return v;
+}
+
+static void display_menu(void)
+{
+	struct card_info *card;
+	struct mode_info *mi;
+	char ch;
+	int i;
+	int nmodes;
+	int modes_per_line;
+	int col;
+
+	nmodes = 0;
+	for (card = video_cards; card < video_cards_end; card++)
+		nmodes += card->nmodes;
+
+	modes_per_line = 1;
+	if (nmodes >= 20)
+		modes_per_line = 3;
+
+	for (col = 0; col < modes_per_line; col++)
+		puts("Mode: Resolution:  Type: ");
+	putchar('\n');
+
+	col = 0;
+	ch = '0';
+	for (card = video_cards; card < video_cards_end; card++) {
+		mi = card->modes;
+		for (i = 0; i < card->nmodes; i++, mi++) {
+			char resbuf[32];
+			int visible = mi->x && mi->y;
+			u16 mode_id = mi->mode ? mi->mode :
+				(mi->y << 8)+mi->x;
+
+			if (!visible)
+				continue; /* Hidden mode */
+
+			if (mi->depth)
+				sprintf(resbuf, "%dx%d", mi->y, mi->depth);
+			else
+				sprintf(resbuf, "%d", mi->y);
+
+			printf("%c %03X %4dx%-7s %-6s",
+			       ch, mode_id, mi->x, resbuf, card->card_name);
+			col++;
+			if (col >= modes_per_line) {
+				putchar('\n');
+				col = 0;
+			}
+
+			if (ch == '9')
+				ch = 'a';
+			else if (ch == 'z' || ch == ' ')
+				ch = ' '; /* Out of keys... */
+			else
+				ch++;
+		}
+	}
+	if (col)
+		putchar('\n');
+}
+
+#define H(x)	((x)-'a'+10)
+#define SCAN	((H('s')<<12)+(H('c')<<8)+(H('a')<<4)+H('n'))
+
+static unsigned int mode_menu(void)
+{
+	int key;
+	unsigned int sel;
+
+	puts("Press <ENTER> to see video modes available, "
+	     "<SPACE> to continue, or wait 30 sec\n");
+
+	kbd_flush();
+	while (1) {
+		key = getchar_timeout();
+		if (key == ' ' || key == 0)
+			return VIDEO_CURRENT_MODE; /* Default */
+		if (key == '\r')
+			break;
+		putchar('\a');	/* Beep! */
+	}
+
+
+	for (;;) {
+		display_menu();
+
+		puts("Enter a video mode or \"scan\" to scan for "
+		     "additional modes: ");
+		sel = get_entry();
+		if (sel != SCAN)
+			return sel;
+
+		probe_cards(1);
+	}
+}
+
+/* Save screen content to the heap */
+static struct saved_screen {
+	int x, y;
+	int curx, cury;
+	u16 *data;
+} saved;
+
+static void save_screen(void)
+{
+	/* Should be called after store_mode_params() */
+	saved.x = boot_params.screen_info.orig_video_cols;
+	saved.y = boot_params.screen_info.orig_video_lines;
+	saved.curx = boot_params.screen_info.orig_x;
+	saved.cury = boot_params.screen_info.orig_y;
+
+	if (!heap_free(saved.x*saved.y*sizeof(u16)+512))
+		return;		/* Not enough heap to save the screen */
+
+	saved.data = GET_HEAP(u16, saved.x*saved.y);
+
+	set_fs(video_segment);
+	copy_from_fs(saved.data, 0, saved.x*saved.y*sizeof(u16));
+}
+
+static void restore_screen(void)
+{
+	/* Should be called after store_mode_params() */
+	int xs = boot_params.screen_info.orig_video_cols;
+	int ys = boot_params.screen_info.orig_video_lines;
+	int y;
+	addr_t dst = 0;
+	u16 *src = saved.data;
+	struct biosregs ireg;
+
+	if (graphic_mode)
+		return;		/* Can't restore onto a graphic mode */
+
+	if (!src)
+		return;		/* No saved screen contents */
+
+	/* Restore screen contents */
+
+	set_fs(video_segment);
+	for (y = 0; y < ys; y++) {
+		int npad;
+
+		if (y < saved.y) {
+			int copy = (xs < saved.x) ? xs : saved.x;
+			copy_to_fs(dst, src, copy*sizeof(u16));
+			dst += copy*sizeof(u16);
+			src += saved.x;
+			npad = (xs < saved.x) ? 0 : xs-saved.x;
+		} else {
+			npad = xs;
+		}
+
+		/* Writes "npad" blank characters to
+		   video_segment:dst and advances dst */
+		asm volatile("pushw %%es ; "
+			     "movw %2,%%es ; "
+			     "shrw %%cx ; "
+			     "jnc 1f ; "
+			     "stosw \n\t"
+			     "1: rep stosl ; "
+			     "popw %%es"
+			     : "+D" (dst), "+c" (npad)
+			     : "bdS" (video_segment),
+			       "a" (0x07200720));
+	}
+
+	/* Restore cursor position */
+	if (saved.curx >= xs)
+		saved.curx = xs-1;
+	if (saved.cury >= ys)
+		saved.cury = ys-1;
+
+	initregs(&ireg);
+	ireg.ah = 0x02;		/* Set cursor position */
+	ireg.dh = saved.cury;
+	ireg.dl = saved.curx;
+	intcall(0x10, &ireg, NULL);
+
+	store_cursor_position();
+}
+
+void set_video(void)
+{
+	u16 mode = boot_params.hdr.vid_mode;
+
+	RESET_HEAP();
+
+	store_mode_params();
+	save_screen();
+	probe_cards(0);
+
+	for (;;) {
+		if (mode == ASK_VGA)
+			mode = mode_menu();
+
+		if (!set_mode(mode))
+			break;
+
+		printf("Undefined video mode number: %x\n", mode);
+		mode = ASK_VGA;
+	}
+	boot_params.hdr.vid_mode = mode;
+	vesa_store_edid();
+	store_mode_params();
+
+	if (do_restore)
+		restore_screen();
+}

linux-7.2.3/arch/x86/boot/video.h

@@ -0,0 +1,118 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Header file for the real-mode video probing code
+ */
+
+#ifndef BOOT_VIDEO_H
+#define BOOT_VIDEO_H
+
+#include <linux/types.h>
+
+/*
+ * This code uses an extended set of video mode numbers. These include:
+ * Aliases for standard modes
+ *      NORMAL_VGA (-1)
+ *      EXTENDED_VGA (-2)
+ *      ASK_VGA (-3)
+ * Video modes numbered by menu position -- NOT RECOMMENDED because of lack
+ * of compatibility when extending the table. These are between 0x00 and 0xff.
+ */
+#define VIDEO_FIRST_MENU 0x0000
+
+/* Standard BIOS video modes (BIOS number + 0x0100) */
+#define VIDEO_FIRST_BIOS 0x0100
+
+/* VESA BIOS video modes (VESA number + 0x0200) */
+#define VIDEO_FIRST_VESA 0x0200
+
+/* Video7 special modes (BIOS number + 0x0900) */
+#define VIDEO_FIRST_V7 0x0900
+
+/* Special video modes */
+#define VIDEO_FIRST_SPECIAL 0x0f00
+#define VIDEO_80x25 0x0f00
+#define VIDEO_8POINT 0x0f01
+#define VIDEO_80x43 0x0f02
+#define VIDEO_80x28 0x0f03
+#define VIDEO_CURRENT_MODE 0x0f04
+#define VIDEO_80x30 0x0f05
+#define VIDEO_80x34 0x0f06
+#define VIDEO_80x60 0x0f07
+#define VIDEO_GFX_HACK 0x0f08
+#define VIDEO_LAST_SPECIAL 0x0f09
+
+/* Video modes given by resolution */
+#define VIDEO_FIRST_RESOLUTION 0x1000
+
+/* The "recalculate timings" flag */
+#define VIDEO_RECALC 0x8000
+
+void store_screen(void);
+#define DO_STORE() store_screen()
+
+/*
+ * Mode table structures
+ */
+
+struct mode_info {
+	u16 mode;		/* Mode number (vga= style) */
+	u16 x, y;		/* Width, height */
+	u16 depth;		/* Bits per pixel, 0 for text mode */
+};
+
+struct card_info {
+	const char *card_name;
+	int (*set_mode)(struct mode_info *mode);
+	int (*probe)(void);
+	struct mode_info *modes;
+	int nmodes;		/* Number of probed modes so far */
+	int unsafe;		/* Probing is unsafe, only do after "scan" */
+	u16 xmode_first;	/* Unprobed modes to try to call anyway */
+	u16 xmode_n;		/* Size of unprobed mode range */
+};
+
+#define __videocard struct card_info __section(".videocards") __attribute__((used))
+extern struct card_info video_cards[], video_cards_end[];
+
+int mode_defined(u16 mode);	/* video.c */
+
+/* Basic video information */
+#define ADAPTER_CGA	0	/* CGA/MDA/HGC */
+#define ADAPTER_EGA	1
+#define ADAPTER_VGA	2
+
+extern int adapter;
+extern int force_x, force_y;	/* Don't query the BIOS for cols/rows */
+extern int do_restore;		/* Restore screen contents */
+extern int graphic_mode;	/* Graphics mode with linear frame buffer */
+
+/* Accessing VGA indexed registers */
+static inline u8 in_idx(u16 port, u8 index)
+{
+	outb(index, port);
+	return inb(port+1);
+}
+
+static inline void out_idx(u8 v, u16 port, u8 index)
+{
+	outw(index+(v << 8), port);
+}
+
+/* Writes a value to an indexed port and then reads the port again */
+static inline u8 tst_idx(u8 v, u16 port, u8 index)
+{
+	out_idx(port, index, v);
+	return in_idx(port, index);
+}
+
+/* Get the I/O port of the VGA CRTC */
+u16 vga_crtc(void);		/* video-vga.c */
+
+#endif /* BOOT_VIDEO_H */