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/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2009,2010 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/>.
*/
/* The code segment of the protected mode. */
#define CODE_SEGMENT 0x10
/* The data segment of the protected mode. */
#define DATA_SEGMENT 0x18
#include "relocator_common.S"
.p2align 4 /* force 16-byte alignment */
VARIABLE(grub_relocator32_start)
PREAMBLE
RELOAD_GDT
.code32
/* Update other registers. */
movl $DATA_SEGMENT, %eax
movl %eax, %ds
movl %eax, %es
movl %eax, %fs
movl %eax, %gs
movl %eax, %ss
DISABLE_PAGING
#ifdef __x86_64__
/* Disable amd64. */
movl $GRUB_MEMORY_CPU_AMD64_MSR, %ecx
rdmsr
andl $(~GRUB_MEMORY_CPU_AMD64_MSR_ON), %eax
wrmsr
#endif
/* Turn off PAE. */
movl %cr4, %eax
andl $(~GRUB_MEMORY_CPU_CR4_PAE_ON), %eax
movl %eax, %cr4
jmp LOCAL(cont2)
LOCAL(cont2):
.code32
/* mov imm32, %eax */
.byte 0xb8
VARIABLE(grub_relocator32_esp)
.long 0
movl %eax, %esp
/* mov imm32, %eax */
.byte 0xb8
VARIABLE(grub_relocator32_ebp)
.long 0
movl %eax, %ebp
/* mov imm32, %eax */
.byte 0xb8
VARIABLE(grub_relocator32_esi)
.long 0
movl %eax, %esi
/* mov imm32, %eax */
.byte 0xb8
VARIABLE(grub_relocator32_edi)
.long 0
movl %eax, %edi
/* mov imm32, %eax */
.byte 0xb8
VARIABLE(grub_relocator32_eax)
.long 0
/* mov imm32, %ebx */
.byte 0xbb
VARIABLE(grub_relocator32_ebx)
.long 0
/* mov imm32, %ecx */
.byte 0xb9
VARIABLE(grub_relocator32_ecx)
.long 0
/* mov imm32, %edx */
.byte 0xba
VARIABLE(grub_relocator32_edx)
.long 0
/* Cleared direction flag is of no problem with any current
payload and makes this implementation easier. */
cld
.byte 0xea
VARIABLE(grub_relocator32_eip)
.long 0
.word CODE_SEGMENT
/* GDT. Copied from loader/i386/linux.c. */
.p2align 4
LOCAL(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
LOCAL(gdt_end):
VARIABLE(grub_relocator32_end)
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