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/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 1999,2000,2001,2002,2003,2005,2006,2007,2008,2009 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 <config.h>
#include <grub/symbol.h>
#include <grub/i386/pc/memory.h>
#include <grub/machine/memory.h>
#include <grub/machine/kernel.h>
.text
.code32
.globl _start
_start:
jmp codestart
. = _start + GRUB_KERNEL_I386_QEMU_CORE_ENTRY_ADDR
VARIABLE(grub_core_entry_addr)
.long 0
VARIABLE(grub_kernel_image_size)
.long 0
VARIABLE(grub_prefix)
/* to be filled by grub-mkimage */
/*
* Leave some breathing room for the prefix.
*/
. = _start + GRUB_KERNEL_MACHINE_PREFIX_END
codestart:
/* Relocate to low memory. First we figure out our location.
We will derive the rom start address from it. */
call 1f
1: popl %esi
/* Rom size is a multiple of 64 kiB. With this we get the
value of `grub_core_entry_addr' in %esi. */
xorw %si, %si
/* ... which allows us to access `grub_kernel_image_size'
before relocation. */
movl (grub_kernel_image_size - _start)(%esi), %ecx
movl $_start, %edi
cld
rep
movsb
ljmp $GRUB_MEMORY_MACHINE_PROT_MODE_CSEG, $1f
1:
#ifdef APPLE_CC
/* clean out the bss */
bss_start_abs = ABS (bss_start)
bss_end_abs = ABS (bss_end)
movl bss_start_abs, %edi
/* compute the bss length */
movl bss_end_abs, %ecx
subl %edi, %ecx
#else
/* clean out the bss */
movl $BSS_START_SYMBOL, %edi
/* compute the bss length */
movl $END_SYMBOL, %ecx
subl %edi, %ecx
#endif
/* clean out */
xorl %eax, %eax
cld
rep
stosb
/*
* Call the start of main body of C code.
*/
call EXT_C(grub_main)
/* This should never happen. */
cli
1:
hlt
jmp 1b
#include "../realmode.S"
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