summaryrefslogtreecommitdiff
path: root/arch/x86/boot
diff options
context:
space:
mode:
authorIngo Molnar <mingo@elte.hu>2008-07-08 09:43:01 +0200
committerIngo Molnar <mingo@elte.hu>2008-07-08 09:43:01 +0200
commit3c1ca43fafea41e38cb2d0c1684119af4c1de547 (patch)
tree122e41a7b9fca26ea25ea9864180f5016274a8c8 /arch/x86/boot
parent6924d1ab8b7bbe5ab416713f5701b3316b2df85b (diff)
parent6bcb13b35a2ea39be6c7cc0292b8ad1191b1a748 (diff)
Merge branch 'x86/setup' into x86/devel
Diffstat (limited to 'arch/x86/boot')
-rw-r--r--arch/x86/boot/a20.c5
-rw-r--r--arch/x86/boot/compressed/misc.c55
-rw-r--r--arch/x86/boot/compressed/relocs.c198
-rw-r--r--arch/x86/boot/cpu.c2
-rw-r--r--arch/x86/boot/main.c4
-rw-r--r--arch/x86/boot/pmjump.S4
6 files changed, 154 insertions, 114 deletions
diff --git a/arch/x86/boot/a20.c b/arch/x86/boot/a20.c
index e01aafd03bd..4063d630def 100644
--- a/arch/x86/boot/a20.c
+++ b/arch/x86/boot/a20.c
@@ -1,7 +1,7 @@
/* -*- linux-c -*- ------------------------------------------------------- *
*
* Copyright (C) 1991, 1992 Linus Torvalds
- * Copyright 2007 rPath, Inc. - All Rights Reserved
+ * Copyright 2007-2008 rPath, Inc. - All Rights Reserved
*
* This file is part of the Linux kernel, and is made available under
* the terms of the GNU General Public License version 2.
@@ -95,6 +95,9 @@ static void enable_a20_kbc(void)
outb(0xdf, 0x60); /* A20 on */
empty_8042();
+
+ outb(0xff, 0x64); /* Null command, but UHCI wants it */
+ empty_8042();
}
static void enable_a20_fast(void)
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index 90456cee47c..11629e903aa 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -30,6 +30,7 @@
#include <asm/io.h>
#include <asm/page.h>
#include <asm/boot.h>
+#include <asm/bootparam.h>
/* WARNING!!
* This code is compiled with -fPIC and it is relocated dynamically
@@ -187,13 +188,8 @@ static void gzip_release(void **);
/*
* This is set up by the setup-routine at boot-time
*/
-static unsigned char *real_mode; /* Pointer to real-mode data */
-
-#define RM_EXT_MEM_K (*(unsigned short *)(real_mode + 0x2))
-#ifndef STANDARD_MEMORY_BIOS_CALL
-#define RM_ALT_MEM_K (*(unsigned long *)(real_mode + 0x1e0))
-#endif
-#define RM_SCREEN_INFO (*(struct screen_info *)(real_mode+0))
+static struct boot_params *real_mode; /* Pointer to real-mode data */
+static int quiet;
extern unsigned char input_data[];
extern int input_len;
@@ -206,7 +202,8 @@ static void free(void *where);
static void *memset(void *s, int c, unsigned n);
static void *memcpy(void *dest, const void *src, unsigned n);
-static void putstr(const char *);
+static void __putstr(int, const char *);
+#define putstr(__x) __putstr(0, __x)
#ifdef CONFIG_X86_64
#define memptr long
@@ -270,18 +267,24 @@ static void scroll(void)
vidmem[i] = ' ';
}
-static void putstr(const char *s)
+static void __putstr(int error, const char *s)
{
int x, y, pos;
char c;
+#ifndef CONFIG_X86_VERBOSE_BOOTUP
+ if (!error)
+ return;
+#endif
+
#ifdef CONFIG_X86_32
- if (RM_SCREEN_INFO.orig_video_mode == 0 && lines == 0 && cols == 0)
+ if (real_mode->screen_info.orig_video_mode == 0 &&
+ lines == 0 && cols == 0)
return;
#endif
- x = RM_SCREEN_INFO.orig_x;
- y = RM_SCREEN_INFO.orig_y;
+ x = real_mode->screen_info.orig_x;
+ y = real_mode->screen_info.orig_y;
while ((c = *s++) != '\0') {
if (c == '\n') {
@@ -302,8 +305,8 @@ static void putstr(const char *s)
}
}
- RM_SCREEN_INFO.orig_x = x;
- RM_SCREEN_INFO.orig_y = y;
+ real_mode->screen_info.orig_x = x;
+ real_mode->screen_info.orig_y = y;
pos = (x + cols * y) * 2; /* Update cursor position */
outb(14, vidport);
@@ -366,9 +369,9 @@ static void flush_window(void)
static void error(char *x)
{
- putstr("\n\n");
- putstr(x);
- putstr("\n\n -- System halted");
+ __putstr(1, "\n\n");
+ __putstr(1, x);
+ __putstr(1, "\n\n -- System halted");
while (1)
asm("hlt");
@@ -395,7 +398,8 @@ static void parse_elf(void *output)
return;
}
- putstr("Parsing ELF... ");
+ if (!quiet)
+ putstr("Parsing ELF... ");
phdrs = malloc(sizeof(*phdrs) * ehdr.e_phnum);
if (!phdrs)
@@ -430,7 +434,10 @@ asmlinkage void decompress_kernel(void *rmode, memptr heap,
{
real_mode = rmode;
- if (RM_SCREEN_INFO.orig_video_mode == 7) {
+ if (real_mode->hdr.loadflags & QUIET_FLAG)
+ quiet = 1;
+
+ if (real_mode->screen_info.orig_video_mode == 7) {
vidmem = (char *) 0xb0000;
vidport = 0x3b4;
} else {
@@ -438,8 +445,8 @@ asmlinkage void decompress_kernel(void *rmode, memptr heap,
vidport = 0x3d4;
}
- lines = RM_SCREEN_INFO.orig_video_lines;
- cols = RM_SCREEN_INFO.orig_video_cols;
+ lines = real_mode->screen_info.orig_video_lines;
+ cols = real_mode->screen_info.orig_video_cols;
window = output; /* Output buffer (Normally at 1M) */
free_mem_ptr = heap; /* Heap */
@@ -465,9 +472,11 @@ asmlinkage void decompress_kernel(void *rmode, memptr heap,
#endif
makecrc();
- putstr("\nDecompressing Linux... ");
+ if (!quiet)
+ putstr("\nDecompressing Linux... ");
gunzip();
parse_elf(output);
- putstr("done.\nBooting the kernel.\n");
+ if (!quiet)
+ putstr("done.\nBooting the kernel.\n");
return;
}
diff --git a/arch/x86/boot/compressed/relocs.c b/arch/x86/boot/compressed/relocs.c
index edaadea90aa..a1310c52fc0 100644
--- a/arch/x86/boot/compressed/relocs.c
+++ b/arch/x86/boot/compressed/relocs.c
@@ -10,16 +10,20 @@
#define USE_BSD
#include <endian.h>
-#define MAX_SHDRS 100
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
static Elf32_Ehdr ehdr;
-static Elf32_Shdr shdr[MAX_SHDRS];
-static Elf32_Sym *symtab[MAX_SHDRS];
-static Elf32_Rel *reltab[MAX_SHDRS];
-static char *strtab[MAX_SHDRS];
static unsigned long reloc_count, reloc_idx;
static unsigned long *relocs;
+struct section {
+ Elf32_Shdr shdr;
+ struct section *link;
+ Elf32_Sym *symtab;
+ Elf32_Rel *reltab;
+ char *strtab;
+};
+static struct section *secs;
+
/*
* Following symbols have been audited. There values are constant and do
* not change if bzImage is loaded at a different physical address than
@@ -35,7 +39,7 @@ static int is_safe_abs_reloc(const char* sym_name)
{
int i;
- for(i = 0; i < ARRAY_SIZE(safe_abs_relocs); i++) {
+ for (i = 0; i < ARRAY_SIZE(safe_abs_relocs); i++) {
if (!strcmp(sym_name, safe_abs_relocs[i]))
/* Match found */
return 1;
@@ -137,10 +141,10 @@ static const char *sec_name(unsigned shndx)
{
const char *sec_strtab;
const char *name;
- sec_strtab = strtab[ehdr.e_shstrndx];
+ sec_strtab = secs[ehdr.e_shstrndx].strtab;
name = "<noname>";
if (shndx < ehdr.e_shnum) {
- name = sec_strtab + shdr[shndx].sh_name;
+ name = sec_strtab + secs[shndx].shdr.sh_name;
}
else if (shndx == SHN_ABS) {
name = "ABSOLUTE";
@@ -159,7 +163,7 @@ static const char *sym_name(const char *sym_strtab, Elf32_Sym *sym)
name = sym_strtab + sym->st_name;
}
else {
- name = sec_name(shdr[sym->st_shndx].sh_name);
+ name = sec_name(secs[sym->st_shndx].shdr.sh_name);
}
return name;
}
@@ -244,29 +248,34 @@ static void read_ehdr(FILE *fp)
static void read_shdrs(FILE *fp)
{
int i;
- if (ehdr.e_shnum > MAX_SHDRS) {
- die("%d section headers supported: %d\n",
- ehdr.e_shnum, MAX_SHDRS);
+ Elf32_Shdr shdr;
+
+ secs = calloc(ehdr.e_shnum, sizeof(struct section));
+ if (!secs) {
+ die("Unable to allocate %d section headers\n",
+ ehdr.e_shnum);
}
if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) {
die("Seek to %d failed: %s\n",
ehdr.e_shoff, strerror(errno));
}
- if (fread(&shdr, sizeof(shdr[0]), ehdr.e_shnum, fp) != ehdr.e_shnum) {
- die("Cannot read ELF section headers: %s\n",
- strerror(errno));
- }
- for(i = 0; i < ehdr.e_shnum; i++) {
- shdr[i].sh_name = elf32_to_cpu(shdr[i].sh_name);
- shdr[i].sh_type = elf32_to_cpu(shdr[i].sh_type);
- shdr[i].sh_flags = elf32_to_cpu(shdr[i].sh_flags);
- shdr[i].sh_addr = elf32_to_cpu(shdr[i].sh_addr);
- shdr[i].sh_offset = elf32_to_cpu(shdr[i].sh_offset);
- shdr[i].sh_size = elf32_to_cpu(shdr[i].sh_size);
- shdr[i].sh_link = elf32_to_cpu(shdr[i].sh_link);
- shdr[i].sh_info = elf32_to_cpu(shdr[i].sh_info);
- shdr[i].sh_addralign = elf32_to_cpu(shdr[i].sh_addralign);
- shdr[i].sh_entsize = elf32_to_cpu(shdr[i].sh_entsize);
+ for (i = 0; i < ehdr.e_shnum; i++) {
+ struct section *sec = &secs[i];
+ if (fread(&shdr, sizeof shdr, 1, fp) != 1)
+ die("Cannot read ELF section headers %d/%d: %s\n",
+ i, ehdr.e_shnum, strerror(errno));
+ sec->shdr.sh_name = elf32_to_cpu(shdr.sh_name);
+ sec->shdr.sh_type = elf32_to_cpu(shdr.sh_type);
+ sec->shdr.sh_flags = elf32_to_cpu(shdr.sh_flags);
+ sec->shdr.sh_addr = elf32_to_cpu(shdr.sh_addr);
+ sec->shdr.sh_offset = elf32_to_cpu(shdr.sh_offset);
+ sec->shdr.sh_size = elf32_to_cpu(shdr.sh_size);
+ sec->shdr.sh_link = elf32_to_cpu(shdr.sh_link);
+ sec->shdr.sh_info = elf32_to_cpu(shdr.sh_info);
+ sec->shdr.sh_addralign = elf32_to_cpu(shdr.sh_addralign);
+ sec->shdr.sh_entsize = elf32_to_cpu(shdr.sh_entsize);
+ if (sec->shdr.sh_link < ehdr.e_shnum)
+ sec->link = &secs[sec->shdr.sh_link];
}
}
@@ -274,20 +283,22 @@ static void read_shdrs(FILE *fp)
static void read_strtabs(FILE *fp)
{
int i;
- for(i = 0; i < ehdr.e_shnum; i++) {
- if (shdr[i].sh_type != SHT_STRTAB) {
+ for (i = 0; i < ehdr.e_shnum; i++) {
+ struct section *sec = &secs[i];
+ if (sec->shdr.sh_type != SHT_STRTAB) {
continue;
}
- strtab[i] = malloc(shdr[i].sh_size);
- if (!strtab[i]) {
+ sec->strtab = malloc(sec->shdr.sh_size);
+ if (!sec->strtab) {
die("malloc of %d bytes for strtab failed\n",
- shdr[i].sh_size);
+ sec->shdr.sh_size);
}
- if (fseek(fp, shdr[i].sh_offset, SEEK_SET) < 0) {
+ if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
die("Seek to %d failed: %s\n",
- shdr[i].sh_offset, strerror(errno));
+ sec->shdr.sh_offset, strerror(errno));
}
- if (fread(strtab[i], 1, shdr[i].sh_size, fp) != shdr[i].sh_size) {
+ if (fread(sec->strtab, 1, sec->shdr.sh_size, fp)
+ != sec->shdr.sh_size) {
die("Cannot read symbol table: %s\n",
strerror(errno));
}
@@ -297,28 +308,31 @@ static void read_strtabs(FILE *fp)
static void read_symtabs(FILE *fp)
{
int i,j;
- for(i = 0; i < ehdr.e_shnum; i++) {
- if (shdr[i].sh_type != SHT_SYMTAB) {
+ for (i = 0; i < ehdr.e_shnum; i++) {
+ struct section *sec = &secs[i];
+ if (sec->shdr.sh_type != SHT_SYMTAB) {
continue;
}
- symtab[i] = malloc(shdr[i].sh_size);
- if (!symtab[i]) {
+ sec->symtab = malloc(sec->shdr.sh_size);
+ if (!sec->symtab) {
die("malloc of %d bytes for symtab failed\n",
- shdr[i].sh_size);
+ sec->shdr.sh_size);
}
- if (fseek(fp, shdr[i].sh_offset, SEEK_SET) < 0) {
+ if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
die("Seek to %d failed: %s\n",
- shdr[i].sh_offset, strerror(errno));
+ sec->shdr.sh_offset, strerror(errno));
}
- if (fread(symtab[i], 1, shdr[i].sh_size, fp) != shdr[i].sh_size) {
+ if (fread(sec->symtab, 1, sec->shdr.sh_size, fp)
+ != sec->shdr.sh_size) {
die("Cannot read symbol table: %s\n",
strerror(errno));
}
- for(j = 0; j < shdr[i].sh_size/sizeof(symtab[i][0]); j++) {
- symtab[i][j].st_name = elf32_to_cpu(symtab[i][j].st_name);
- symtab[i][j].st_value = elf32_to_cpu(symtab[i][j].st_value);
- symtab[i][j].st_size = elf32_to_cpu(symtab[i][j].st_size);
- symtab[i][j].st_shndx = elf16_to_cpu(symtab[i][j].st_shndx);
+ for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Sym); j++) {
+ Elf32_Sym *sym = &sec->symtab[j];
+ sym->st_name = elf32_to_cpu(sym->st_name);
+ sym->st_value = elf32_to_cpu(sym->st_value);
+ sym->st_size = elf32_to_cpu(sym->st_size);
+ sym->st_shndx = elf16_to_cpu(sym->st_shndx);
}
}
}
@@ -327,26 +341,29 @@ static void read_symtabs(FILE *fp)
static void read_relocs(FILE *fp)
{
int i,j;
- for(i = 0; i < ehdr.e_shnum; i++) {
- if (shdr[i].sh_type != SHT_REL) {
+ for (i = 0; i < ehdr.e_shnum; i++) {
+ struct section *sec = &secs[i];
+ if (sec->shdr.sh_type != SHT_REL) {
continue;
}
- reltab[i] = malloc(shdr[i].sh_size);
- if (!reltab[i]) {
+ sec->reltab = malloc(sec->shdr.sh_size);
+ if (!sec->reltab) {
die("malloc of %d bytes for relocs failed\n",
- shdr[i].sh_size);
+ sec->shdr.sh_size);
}
- if (fseek(fp, shdr[i].sh_offset, SEEK_SET) < 0) {
+ if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
die("Seek to %d failed: %s\n",
- shdr[i].sh_offset, strerror(errno));
+ sec->shdr.sh_offset, strerror(errno));
}
- if (fread(reltab[i], 1, shdr[i].sh_size, fp) != shdr[i].sh_size) {
+ if (fread(sec->reltab, 1, sec->shdr.sh_size, fp)
+ != sec->shdr.sh_size) {
die("Cannot read symbol table: %s\n",
strerror(errno));
}
- for(j = 0; j < shdr[i].sh_size/sizeof(reltab[0][0]); j++) {
- reltab[i][j].r_offset = elf32_to_cpu(reltab[i][j].r_offset);
- reltab[i][j].r_info = elf32_to_cpu(reltab[i][j].r_info);
+ for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) {
+ Elf32_Rel *rel = &sec->reltab[j];
+ rel->r_offset = elf32_to_cpu(rel->r_offset);
+ rel->r_info = elf32_to_cpu(rel->r_info);
}
}
}
@@ -357,19 +374,21 @@ static void print_absolute_symbols(void)
int i;
printf("Absolute symbols\n");
printf(" Num: Value Size Type Bind Visibility Name\n");
- for(i = 0; i < ehdr.e_shnum; i++) {
+ for (i = 0; i < ehdr.e_shnum; i++) {
+ struct section *sec = &secs[i];
char *sym_strtab;
Elf32_Sym *sh_symtab;
int j;
- if (shdr[i].sh_type != SHT_SYMTAB) {
+
+ if (sec->shdr.sh_type != SHT_SYMTAB) {
continue;
}
- sh_symtab = symtab[i];
- sym_strtab = strtab[shdr[i].sh_link];
- for(j = 0; j < shdr[i].sh_size/sizeof(symtab[0][0]); j++) {
+ sh_symtab = sec->symtab;
+ sym_strtab = sec->link->strtab;
+ for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Sym); j++) {
Elf32_Sym *sym;
const char *name;
- sym = &symtab[i][j];
+ sym = &sec->symtab[j];
name = sym_name(sym_strtab, sym);
if (sym->st_shndx != SHN_ABS) {
continue;
@@ -389,26 +408,27 @@ static void print_absolute_relocs(void)
{
int i, printed = 0;
- for(i = 0; i < ehdr.e_shnum; i++) {
+ for (i = 0; i < ehdr.e_shnum; i++) {
+ struct section *sec = &secs[i];
+ struct section *sec_applies, *sec_symtab;
char *sym_strtab;
Elf32_Sym *sh_symtab;
- unsigned sec_applies, sec_symtab;
int j;
- if (shdr[i].sh_type != SHT_REL) {
+ if (sec->shdr.sh_type != SHT_REL) {
continue;
}
- sec_symtab = shdr[i].sh_link;
- sec_applies = shdr[i].sh_info;
- if (!(shdr[sec_applies].sh_flags & SHF_ALLOC)) {
+ sec_symtab = sec->link;
+ sec_applies = &secs[sec->shdr.sh_info];
+ if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) {
continue;
}
- sh_symtab = symtab[sec_symtab];
- sym_strtab = strtab[shdr[sec_symtab].sh_link];
- for(j = 0; j < shdr[i].sh_size/sizeof(reltab[0][0]); j++) {
+ sh_symtab = sec_symtab->symtab;
+ sym_strtab = sec_symtab->link->strtab;
+ for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) {
Elf32_Rel *rel;
Elf32_Sym *sym;
const char *name;
- rel = &reltab[i][j];
+ rel = &sec->reltab[j];
sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
name = sym_name(sym_strtab, sym);
if (sym->st_shndx != SHN_ABS) {
@@ -456,26 +476,28 @@ static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym))
{
int i;
/* Walk through the relocations */
- for(i = 0; i < ehdr.e_shnum; i++) {
+ for (i = 0; i < ehdr.e_shnum; i++) {
char *sym_strtab;
Elf32_Sym *sh_symtab;
- unsigned sec_applies, sec_symtab;
+ struct section *sec_applies, *sec_symtab;
int j;
- if (shdr[i].sh_type != SHT_REL) {
+ struct section *sec = &secs[i];
+
+ if (sec->shdr.sh_type != SHT_REL) {
continue;
}
- sec_symtab = shdr[i].sh_link;
- sec_applies = shdr[i].sh_info;
- if (!(shdr[sec_applies].sh_flags & SHF_ALLOC)) {
+ sec_symtab = sec->link;
+ sec_applies = &secs[sec->shdr.sh_info];
+ if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) {
continue;
}
- sh_symtab = symtab[sec_symtab];
- sym_strtab = strtab[shdr[sec_symtab].sh_link];
- for(j = 0; j < shdr[i].sh_size/sizeof(reltab[0][0]); j++) {
+ sh_symtab = sec_symtab->symtab;
+ sym_strtab = sec->link->strtab;
+ for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) {
Elf32_Rel *rel;
Elf32_Sym *sym;
unsigned r_type;
- rel = &reltab[i][j];
+ rel = &sec->reltab[j];
sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
r_type = ELF32_R_TYPE(rel->r_info);
/* Don't visit relocations to absolute symbols */
@@ -539,7 +561,7 @@ static void emit_relocs(int as_text)
*/
printf(".section \".data.reloc\",\"a\"\n");
printf(".balign 4\n");
- for(i = 0; i < reloc_count; i++) {
+ for (i = 0; i < reloc_count; i++) {
printf("\t .long 0x%08lx\n", relocs[i]);
}
printf("\n");
@@ -550,7 +572,7 @@ static void emit_relocs(int as_text)
/* Print a stop */
printf("%c%c%c%c", buf[0], buf[1], buf[2], buf[3]);
/* Now print each relocation */
- for(i = 0; i < reloc_count; i++) {
+ for (i = 0; i < reloc_count; i++) {
buf[0] = (relocs[i] >> 0) & 0xff;
buf[1] = (relocs[i] >> 8) & 0xff;
buf[2] = (relocs[i] >> 16) & 0xff;
@@ -577,7 +599,7 @@ int main(int argc, char **argv)
show_absolute_relocs = 0;
as_text = 0;
fname = NULL;
- for(i = 1; i < argc; i++) {
+ for (i = 1; i < argc; i++) {
char *arg = argv[i];
if (*arg == '-') {
if (strcmp(argv[1], "--abs-syms") == 0) {
diff --git a/arch/x86/boot/cpu.c b/arch/x86/boot/cpu.c
index 00e19edd852..92d6fd73dc7 100644
--- a/arch/x86/boot/cpu.c
+++ b/arch/x86/boot/cpu.c
@@ -28,6 +28,8 @@ static char *cpu_name(int level)
if (level == 64) {
return "x86-64";
} else {
+ if (level == 15)
+ level = 6;
sprintf(buf, "i%d86", level);
return buf;
}
diff --git a/arch/x86/boot/main.c b/arch/x86/boot/main.c
index 77569a4a3be..2296164b54d 100644
--- a/arch/x86/boot/main.c
+++ b/arch/x86/boot/main.c
@@ -165,6 +165,10 @@ void main(void)
/* Set the video mode */
set_video();
+ /* Parse command line for 'quiet' and pass it to decompressor. */
+ if (cmdline_find_option_bool("quiet"))
+ boot_params.hdr.loadflags |= QUIET_FLAG;
+
/* Do the last things and invoke protected mode */
go_to_protected_mode();
}
diff --git a/arch/x86/boot/pmjump.S b/arch/x86/boot/pmjump.S
index ab049d40a88..141b6e20ed3 100644
--- a/arch/x86/boot/pmjump.S
+++ b/arch/x86/boot/pmjump.S
@@ -33,6 +33,8 @@ protected_mode_jump:
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
@@ -40,8 +42,6 @@ protected_mode_jump:
movl %cr0, %edx
orb $X86_CR0_PE, %dl # Protected mode
movl %edx, %cr0
- jmp 1f # Short jump to serialize on 386/486
-1:
# Transition to 32-bit mode
.byte 0x66, 0xea # ljmpl opcode