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lib/relocator

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This commit is contained in:
Vladimir 'phcoder' Serbinenko 2009-08-03 12:48:25 +02:00
parent f84114f583
commit e7573c5ce2
9 changed files with 509 additions and 120 deletions
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6
conf/i386.rmk
View file

@ -14,3 +14,9 @@ pkglib_MODULES += vga_text.mod
vga_text_mod_SOURCES = term/i386/pc/vga_text.c term/i386/vga_common.c
vga_text_mod_CFLAGS = $(COMMON_CFLAGS)
vga_text_mod_LDFLAGS = $(COMMON_LDFLAGS)
pkglib_MODULES += relocator.mod
relocator_mod_SOURCES = lib/i386/relocator.c lib/i386/relocator_asm.S lib/i386/relocator_backward.S
relocator_mod_CFLAGS = $(COMMON_CFLAGS)
relocator_mod_ASFLAGS = $(COMMON_ASFLAGS)
relocator_mod_LDFLAGS = $(COMMON_LDFLAGS)

11
include/grub/i386/multiboot.h
View file

@ -27,16 +27,11 @@ void grub_multiboot2_real_boot (grub_addr_t entry,
struct grub_multiboot_info *mbi)
__attribute__ ((noreturn));
extern grub_addr_t grub_multiboot_payload_orig;
extern grub_uint32_t grub_multiboot_payload_eip;
extern char *grub_multiboot_payload_orig;
extern grub_addr_t grub_multiboot_payload_dest;
extern grub_size_t grub_multiboot_payload_size;
extern grub_uint32_t grub_multiboot_payload_entry_offset;
extern grub_uint8_t grub_multiboot_forward_relocator;
extern grub_uint8_t grub_multiboot_forward_relocator_end;
extern grub_uint8_t grub_multiboot_backward_relocator;
extern grub_uint8_t grub_multiboot_backward_relocator_end;
#define RELOCATOR_SIZEOF(x) (&grub_multiboot_##x##_relocator_end - &grub_multiboot_##x##_relocator)
#define GRUB_MULTIBOOT_STACK_SIZE 4096
#endif /* ! GRUB_MULTIBOOT_CPU_HEADER */

40
include/grub/i386/relocator.h Normal file
View file

@ -0,0 +1,40 @@
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2009 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef GRUB_RELOCATOR_CPU_HEADER
#define GRUB_RELOCATOR_CPU_HEADER 1
struct grub_relocator32_state
{
grub_uint32_t esp;
grub_uint32_t eax;
grub_uint32_t ebx;
grub_uint32_t ecx;
grub_uint32_t edx;
grub_uint32_t eip;
};
void *
grub_relocator32_alloc (grub_size_t size);
grub_err_t
grub_relocator32_boot (void *relocator, grub_uint32_t dest,
struct grub_relocator32_state state);
void
grub_relocator32_free (void *relocator);
#endif /* ! GRUB_RELOCATOR_CPU_HEADER */

148
lib/i386/relocator.c Normal file
View file

@ -0,0 +1,148 @@
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2009 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/mm.h>
#include <grub/misc.h>
#include <grub/types.h>
#include <grub/types.h>
#include <grub/err.h>
#include <grub/i386/relocator.h>
extern grub_uint8_t grub_relocator32_forward_start;
extern grub_uint8_t grub_relocator32_forward_end;
extern grub_uint8_t grub_relocator32_backward_start;
extern grub_uint8_t grub_relocator32_backward_end;
extern grub_uint32_t grub_relocator32_backward_dest;
extern grub_uint32_t grub_relocator32_backward_size;
#ifdef __x86_64__
extern grub_uint64_t grub_relocator32_backward_src;
#else
extern grub_uint32_t grub_relocator32_backward_src;
#endif
extern grub_uint32_t grub_relocator32_forward_dest;
extern grub_uint32_t grub_relocator32_forward_size;
#ifdef __x86_64__
extern grub_uint64_t grub_relocator32_forward_src;
#else
extern grub_uint32_t grub_relocator32_forward_src;
#endif
extern grub_uint32_t grub_relocator32_forward_eax;
extern grub_uint32_t grub_relocator32_forward_ebx;
extern grub_uint32_t grub_relocator32_forward_ecx;
extern grub_uint32_t grub_relocator32_forward_edx;
extern grub_uint32_t grub_relocator32_forward_eip;
extern grub_uint32_t grub_relocator32_forward_esp;
extern grub_uint32_t grub_relocator32_backward_eax;
extern grub_uint32_t grub_relocator32_backward_ebx;
extern grub_uint32_t grub_relocator32_backward_ecx;
extern grub_uint32_t grub_relocator32_backward_edx;
extern grub_uint32_t grub_relocator32_backward_eip;
extern grub_uint32_t grub_relocator32_backward_esp;
#define RELOCATOR_SIZEOF(x) (&grub_relocator32_##x##_end - &grub_relocator32_##x##_start)
#define RELOCATOR_ALIGN 16
void *
grub_relocator32_alloc (grub_size_t size)
{
char *playground;
playground = grub_malloc ((RELOCATOR_SIZEOF(forward) + RELOCATOR_ALIGN)
+ size
+ (RELOCATOR_SIZEOF(backward) + RELOCATOR_ALIGN));
if (! playground)
return 0;
*(grub_size_t *) playground = size;
return playground + RELOCATOR_SIZEOF(forward);
}
void
grub_relocator32_free (void *relocator)
{
if (relocator)
grub_free ((char *) relocator - RELOCATOR_SIZEOF(forward));
}
grub_err_t
grub_relocator32_boot (void *relocator, grub_uint32_t dest,
struct grub_relocator32_state state)
{
grub_size_t size;
char *playground;
void (*entry) ();
playground = (char *) relocator - RELOCATOR_SIZEOF(forward);
size = *(grub_size_t *) playground;
if (UINT_TO_PTR (dest) >= relocator)
{
int overhead;
overhead = ALIGN_UP (dest - RELOCATOR_SIZEOF(backward) - RELOCATOR_ALIGN, RELOCATOR_ALIGN);
grub_relocator32_backward_dest = dest - overhead;
grub_relocator32_backward_src = PTR_TO_UINT64 (relocator - overhead);
grub_relocator32_backward_size = size + overhead;
grub_relocator32_backward_eax = state.eax;
grub_relocator32_backward_ebx = state.ebx;
grub_relocator32_backward_ecx = state.ecx;
grub_relocator32_backward_edx = state.edx;
grub_relocator32_backward_eip = state.eip;
grub_relocator32_backward_esp = state.esp;
grub_memmove (relocator - overhead,
&grub_relocator32_backward_start,
RELOCATOR_SIZEOF(backward));
entry = (void (*) ()) (relocator - overhead);
}
else
{
int overhead;
overhead = ALIGN_UP (dest + size, RELOCATOR_ALIGN)
+ RELOCATOR_SIZEOF(forward) - (dest + size);
grub_relocator32_forward_dest = dest;
grub_relocator32_forward_src = PTR_TO_UINT64 (relocator);
grub_relocator32_forward_size = size + overhead;
grub_relocator32_forward_eax = state.eax;
grub_relocator32_forward_ebx = state.ebx;
grub_relocator32_forward_ecx = state.ecx;
grub_relocator32_forward_edx = state.edx;
grub_relocator32_forward_eip = state.eip;
grub_relocator32_forward_esp = state.esp;
grub_memmove (relocator + size + overhead - RELOCATOR_SIZEOF(forward),
&grub_relocator32_forward_start, RELOCATOR_SIZEOF(forward));
entry = (void (*) ()) (relocator + size + overhead - RELOCATOR_SIZEOF(forward));
}
entry ();
/* Not reached. */
return GRUB_ERR_NONE;
}

269
lib/i386/relocator_asm.S Normal file
View file

@ -0,0 +1,269 @@
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2009 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/symbol.h>
#ifdef BACKWARD
#define RELOCATOR_VARIABLE(x) VARIABLE(grub_relocator32_backward_ ## x)
#else
#define RELOCATOR_VARIABLE(x) VARIABLE(grub_relocator32_forward_ ## x)
#endif
.p2align 4 /* force 16-byte alignment */
RELOCATOR_VARIABLE(start)
#ifdef BACKWARD
base:
#endif
cli
#ifndef __x86_64__
/* mov imm32, %eax */
.byte 0xb8
RELOCATOR_VARIABLE(dest)
.long 0
mov %eax, %edi
/* mov imm32, %eax */
.byte 0xb8
RELOCATOR_VARIABLE(src)
.long 0
mov %eax, %esi
/* mov imm32, %ecx */
.byte 0xb9
RELOCATOR_VARIABLE(size)
.long 0
mov %edi, %eax
#ifndef BACKWARD
add %ecx, %eax
#endif
add $0x3, %ecx
shr $2, %ecx
#ifdef BACKWARD
/* Backward movsl is implicitly off-by-four. compensate that. */
subl $4, %esi
subl $4, %edi
/* Backward copy. */
std
addl %ecx, %esi
addl %ecx, %edi
rep
movsl
#else
/* Forward copy. */
cld
rep
movsl
#endif
/* %eax contains now our new base. */
mov %eax, %esi
add $(cont0 - base), %eax
jmp *%eax
cont0:
#else
xorq %rax, %rax
/* mov imm32, %eax */
.byte 0xb8
RELOCATOR_VARIABLE(dest)
.long 0
mov %eax, %edi
/* mov imm64, %rax */
.byte 0xb8
RELOCATOR_VARIABLE(src)
.long 0, 0
mov %rax, %rsi
xorl %rcx, %rcx
/* mov imm32, %ecx */
.byte 0xb9
RELOCATOR_VARIABLE(size)
.long 0
mov %rdi, %rax
#ifndef BACKWARD
add %rcx, %rax
#endif
add $0x3, %rcx
shr $2, %rcx
#ifdef BACKWARD
/* Backward movsl is implicitly off-by-four. compensate that. */
subl $4, %rsi
subl $4, %rdi
/* Backward copy. */
std
addl %rcx, %rsi
addl %rcx, %rdi
rep
movsl
#else
/* Forward copy. */
cld
rep
movsl
#endif
/* %rax contains now our new 'base'. */
mov %rax, %rsi
#ifdef APPLE_CC
add $(cont0 - base), %eax
#else
add $(cont0 - base), %rax
#endif
jmp *%rax
cont0:
#ifdef APPLE_CC
lea (cont1 - base) (%esi, 1), %eax
mov %eax, (jump_vector - base) (%esi, 1)
lea (gdt - base) (%esi, 1), %eax
mov %eax, (gdt_addr - base) (%esi, 1)
/* Switch to compatibility mode. */
lgdt (gdtdesc - base) (%esi, 1)
/* Update %cs. Thanks to David Miller for pointing this mistake out. */
ljmp *(jump_vector - base) (%esi,1)
#else
lea (cont1 - base) (%rsi, 1), %rax
mov %eax, (jump_vector - base) (%rsi, 1)
lea (gdt - base) (%rsi, 1), %rax
mov %rax, (gdt_addr - base) (%rsi, 1)
/* Switch to compatibility mode. */
lgdt (gdtdesc - base) (%rsi, 1)
/* Update %cs. Thanks to David Miller for pointing this mistake out. */
ljmp *(jump_vector - base) (%rsi, 1)
#endif
cont1:
.code32
/* Update other registers. */
mov $0x18, %eax
mov %eax, %ds
mov %eax, %es
mov %eax, %fs
mov %eax, %gs
mov %eax, %ss
/* Disable paging. */
mov %cr0, %eax
and $0x7fffffff, %eax
mov %eax, %cr0
/* Disable amd64. */
mov $0xc0000080, %ecx
rdmsr
and $0xfffffeff, %eax
wrmsr
/* Turn off PAE. */
movl %cr4, %eax
and $0xffffffcf, %eax
mov %eax, %cr4
jmp cont2
cont2:
#endif
.code32
/* mov imm32, %eax */
.byte 0xb8
RELOCATOR_VARIABLE (esp)
.long 0
movl %eax, %esp
/* mov imm32, %eax */
.byte 0xb8
RELOCATOR_VARIABLE (eax)
.long 0
/* mov imm32, %ebx */
.byte 0xbb
RELOCATOR_VARIABLE (ebx)
.long 0
/* mov imm32, %ecx */
.byte 0xb9
RELOCATOR_VARIABLE (ecx)
.long 0
/* mov imm32, %edx */
.byte 0xba
RELOCATOR_VARIABLE (edx)
.long 0
/* Cleared direction flag is of no problem with any current
payload and makes this implementation easier. */
cld
.byte 0xea
RELOCATOR_VARIABLE (eip)
.long 0
.word 0x08
#ifdef __x86_64__
/* GDT. Copied from loader/i386/linux.c. */
.p2align 4
gdt:
/* NULL. */
.byte 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
/* Reserved. */
.byte 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
/* Code segment. */
.byte 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x9A, 0xCF, 0x00
/* Data segment. */
.byte 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x92, 0xCF, 0x00
gdtdesc:
.word 31
gdt_addr:
/* Filled by the code. */
.quad 0
.p2align 4
jump_vector:
/* Jump location. Is filled by the code */
.long 0
.long 0x10
#endif
#ifndef BACKWARD
base:
#endif
RELOCATOR_VARIABLE(end)

2
lib/i386/relocator_backward.S Normal file
View file

@ -0,0 +1,2 @@
#define BACKWARD
#include "relocator_asm.S"

64
loader/i386/multiboot.c
View file

@ -48,18 +48,35 @@
#include <grub/device.h>
#include <grub/partition.h>
#endif
#include <grub/i386/relocator.h>
extern grub_dl_t my_mod;
static struct grub_multiboot_info *mbi, *mbi_dest;
static grub_addr_t entry;
static char *playground;
static grub_size_t code_size;
char *grub_multiboot_payload_orig;
grub_addr_t grub_multiboot_payload_dest;
grub_size_t grub_multiboot_payload_size;
grub_uint32_t grub_multiboot_payload_eip;
grub_uint32_t grub_multiboot_payload_esp;
static grub_err_t
grub_multiboot_boot (void)
{
grub_multiboot_real_boot (entry, mbi_dest);
struct grub_relocator32_state state =
{
.eax = MULTIBOOT_MAGIC2,
.ebx = PTR_TO_UINT32 (mbi_dest),
.ecx = 0,
.edx = 0,
.eip = grub_multiboot_payload_eip,
.esp = grub_multiboot_payload_esp
};
grub_relocator32_boot (grub_multiboot_payload_orig,
grub_multiboot_payload_dest,
state);
/* Not reached. */
return GRUB_ERR_NONE;
@ -248,11 +265,8 @@ grub_multiboot (int argc, char *argv[])
goto fail;
}
if (playground)
{
grub_free (playground);
playground = NULL;
}
grub_relocator32_free (grub_multiboot_payload_orig);
grub_multiboot_payload_orig = NULL;
mmap_length = grub_get_multiboot_mmap_len ();
@ -267,11 +281,13 @@ grub_multiboot (int argc, char *argv[])
((void *) ((x) + code_size + cmdline_length))
#define mbi_addr(x) ((void *) ((x) + code_size + cmdline_length + boot_loader_name_length))
#define mmap_addr(x) ((void *) ((x) + code_size + cmdline_length + boot_loader_name_length + sizeof (struct grub_multiboot_info)))
#define stack_addr(x) ((void *) ((x) + code_size + cmdline_length + boot_loader_name_length + sizeof (struct grub_multiboot_info) + mmap_length + GRUB_MULTIBOOT_STACK_SIZE))
grub_multiboot_payload_size = cmdline_length
/* boot_loader_name_length might need to grow for mbi,etc to be aligned (see below) */
+ boot_loader_name_length + 3
+ sizeof (struct grub_multiboot_info) + mmap_length;
+ sizeof (struct grub_multiboot_info) + mmap_length
+ GRUB_MULTIBOOT_STACK_SIZE;
if (header->flags & MULTIBOOT_AOUT_KLUDGE)
{
@ -287,11 +303,12 @@ grub_multiboot (int argc, char *argv[])
grub_multiboot_payload_dest = header->load_addr;
grub_multiboot_payload_size += code_size;
playground = grub_malloc (RELOCATOR_SIZEOF(forward) + grub_multiboot_payload_size + RELOCATOR_SIZEOF(backward));
if (! playground)
goto fail;
grub_multiboot_payload_orig = (long) playground + RELOCATOR_SIZEOF(forward);
grub_multiboot_payload_orig
= grub_relocator32_alloc (grub_multiboot_payload_size);
if (! grub_multiboot_payload_orig)
goto fail;
if ((grub_file_seek (file, offset)) == (grub_off_t) - 1)
goto fail;
@ -304,7 +321,7 @@ grub_multiboot (int argc, char *argv[])
grub_memset ((void *) (grub_multiboot_payload_orig + load_size), 0,
header->bss_end_addr - header->load_addr - load_size);
grub_multiboot_payload_entry_offset = header->entry_addr - header->load_addr;
grub_multiboot_payload_eip = header->entry_addr;
}
else if (grub_multiboot_load_elf (file, buffer) != GRUB_ERR_NONE)
@ -325,23 +342,6 @@ grub_multiboot (int argc, char *argv[])
mbi->mmap_addr = (grub_uint32_t) mmap_addr (grub_multiboot_payload_dest);
mbi->flags |= MULTIBOOT_INFO_MEM_MAP;
if (grub_multiboot_payload_dest >= grub_multiboot_payload_orig)
{
grub_memmove (playground, &grub_multiboot_forward_relocator, RELOCATOR_SIZEOF(forward));
entry = (grub_addr_t) playground;
}
else
{
grub_memmove ((char *) (grub_multiboot_payload_orig + grub_multiboot_payload_size),
&grub_multiboot_backward_relocator, RELOCATOR_SIZEOF(backward));
entry = (grub_addr_t) grub_multiboot_payload_orig + grub_multiboot_payload_size;
}
grub_dprintf ("multiboot_loader", "dest=%p, size=0x%x, entry_offset=0x%x\n",
(void *) grub_multiboot_payload_dest,
grub_multiboot_payload_size,
grub_multiboot_payload_entry_offset);
/* Convert from bytes to kilobytes. */
mbi->mem_lower = grub_mmap_get_lower () / 1024;
mbi->mem_upper = grub_mmap_get_upper () / 1024;
@ -371,6 +371,8 @@ grub_multiboot (int argc, char *argv[])
if (grub_multiboot_get_bootdev (&mbi->boot_device))
mbi->flags |= MULTIBOOT_INFO_BOOTDEV;
grub_multiboot_payload_esp = PTR_TO_UINT32 (stack_addr (grub_multiboot_payload_dest));
grub_loader_set (grub_multiboot_boot, grub_multiboot_unload, 1);
fail:

14
loader/i386/multiboot_elfxx.c
View file

@ -32,6 +32,8 @@
#error "I'm confused"
#endif
#include <grub/i386/relocator.h>
#define CONCAT(a,b) CONCAT_(a, b)
#define CONCAT_(a,b) a ## b
@ -99,11 +101,12 @@ CONCAT(grub_multiboot_load_elf, XX) (grub_file_t file, void *buffer)
grub_multiboot_payload_dest = phdr(lowest_segment)->p_paddr;
grub_multiboot_payload_size += code_size;
playground = grub_malloc (RELOCATOR_SIZEOF(forward) + grub_multiboot_payload_size + RELOCATOR_SIZEOF(backward));
if (! playground)
return grub_errno;
grub_multiboot_payload_orig = (long) playground + RELOCATOR_SIZEOF(forward);
grub_multiboot_payload_orig
= grub_relocator32_alloc (grub_multiboot_payload_size);
if (!grub_multiboot_payload_orig)
return grub_errno;
/* Load every loadable segment in memory. */
for (i = 0; i < ehdr->e_phnum; i++)
@ -135,8 +138,7 @@ CONCAT(grub_multiboot_load_elf, XX) (grub_file_t file, void *buffer)
if (phdr(i)->p_vaddr <= ehdr->e_entry
&& phdr(i)->p_vaddr + phdr(i)->p_memsz > ehdr->e_entry)
{
grub_multiboot_payload_entry_offset = (ehdr->e_entry - phdr(i)->p_vaddr)
+ (phdr(i)->p_paddr - phdr(lowest_segment)->p_paddr);
grub_multiboot_payload_eip = ehdr->e_entry;
break;
}

75
loader/i386/multiboot_helper.S
View file

@ -22,81 +22,6 @@
.p2align 2 /* force 4-byte alignment */
/*
* This starts the multiboot kernel.
*/
VARIABLE(grub_multiboot_payload_size)
.long 0
VARIABLE(grub_multiboot_payload_orig)
.long 0
VARIABLE(grub_multiboot_payload_dest)
.long 0
VARIABLE(grub_multiboot_payload_entry_offset)
.long 0
/*
* The relocators below understand the following parameters:
* ecx: Size of the block to be copied.
* esi: Where to copy from (always lowest address, even if we're relocating
* backwards).
* edi: Where to copy to (likewise).
* edx: Offset of the entry point (relative to the beginning of the block).
*/
VARIABLE(grub_multiboot_forward_relocator)
/* Add entry offset. */
addl %edi, %edx
/* Forward copy. */
cld
rep
movsb
jmp *%edx
VARIABLE(grub_multiboot_forward_relocator_end)
VARIABLE(grub_multiboot_backward_relocator)
/* Add entry offset (before %edi is mangled). */
addl %edi, %edx
/* Backward movsb is implicitly off-by-one. compensate that. */
decl %esi
decl %edi
/* Backward copy. */
std
addl %ecx, %esi
addl %ecx, %edi
rep
movsb
cld
jmp *%edx
VARIABLE(grub_multiboot_backward_relocator_end)
FUNCTION(grub_multiboot_real_boot)
/* Push the entry address on the stack. */
pushl %eax
/* Move the address of the multiboot information structure to ebx. */
movl %edx,%ebx
/* Interrupts should be disabled. */
cli
/* Where do we copy what from. */
movl EXT_C(grub_multiboot_payload_size), %ecx
movl EXT_C(grub_multiboot_payload_orig), %esi
movl EXT_C(grub_multiboot_payload_dest), %edi
movl EXT_C(grub_multiboot_payload_entry_offset), %edx
/* Move the magic value into eax. */
movl $MULTIBOOT_MAGIC2, %eax
/* Jump to the relocator. */
popl %ebp
jmp *%ebp
/*
* This starts the multiboot 2 kernel.
*/