grub/kern/x86_64/efi/startup.S
proski fbc00b0ca1 2009-03-22 Pavel Roskin <proski@gno.org>
* kern/powerpc/ieee1275/startup.S: Replace EXT_C(start) with
	_start.
	* kern/i386/pc/startup.S: Likewise.
	* kern/i386/efi/startup.S: Likewise.
	* kern/i386/ieee1275/startup.S: Likewise.
	* kern/i386/coreboot/startup.S: Likewise.
	* kern/x86_64/efi/startup.S: Likewise.
2009-03-22 00:37:49 +00:00

86 lines
2.1 KiB
ArmAsm

/* startup.S - bootstrap GRUB itself */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2006,2007,2009 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/boot.h>
.file "startup.S"
.text
.globl start, _start
.code64
start:
_start:
jmp codestart
/*
* Compatibility version number
*
* These MUST be at byte offset 6 and 7 of the executable
* DO NOT MOVE !!!
*/
. = _start + 0x6
.byte GRUB_BOOT_VERSION_MAJOR, GRUB_BOOT_VERSION_MINOR
/*
* This is a special data area 8 bytes from the beginning.
*/
. = _start + 0x8
VARIABLE(grub_prefix)
/* to be filled by grub-mkimage */
/*
* Leave some breathing room for the prefix.
*/
. = _start + 0x50
codestart:
movq %rcx, EXT_C(grub_efi_image_handle)(%rip)
movq %rdx, EXT_C(grub_efi_system_table)(%rip)
call EXT_C(grub_main)
ret
.code32
FUNCTION(grub_linux_real_boot)
/* Turn off PG bit in CR0 and set CR3 to zero. */
movl %cr0, %eax
andl $0x7FFFFFFF, %eax
movl %eax, %cr0
/* Setup EFER (Extended Feature Enable Register). */
movl $0xc0000080, %ecx
rdmsr
/* Disable Long Mode. */
andl $0xFFFFFEFF, %eax
/* Make changes effective. */
wrmsr
/* Disable PAE. */
xorl %eax, %eax
movl %eax, %cr4
jmp *%ebx