grub/loader/i386/xnu_helper.S
2009-06-10 21:04:23 +00:00

211 lines
3.9 KiB
ArmAsm

/*
* 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>
.p2align 4 /* force 16-byte alignment */
VARIABLE(grub_xnu_launcher_start)
base:
cli
#ifndef __x86_64__
/* mov imm32, %eax */
.byte 0xb8
VARIABLE(grub_xnu_heap_will_be_at)
.long 0
mov %eax, %edi
/* mov imm32, %eax */
.byte 0xb8
VARIABLE(grub_xnu_heap_start)
.long 0
mov %eax, %esi
/* mov imm32, %ecx */
.byte 0xb9
VARIABLE(grub_xnu_heap_size)
.long 0
mov %edi, %eax
add %ecx, %eax
/* %rax now contains our starting position after relocation. */
/* One more page to copy: ourselves. */
add $0x403, %ecx
shr $2, %ecx
/* Forward copy. */
cld
rep
movsl
mov %eax, %esi
add $(cont0-base), %eax
jmp *%eax
cont0:
#else
xorq %rax, %rax
/* mov imm32, %eax */
.byte 0xb8
VARIABLE(grub_xnu_heap_will_be_at)
.long 0
mov %rax, %rdi
/* mov imm32, %rax */
.byte 0x48
.byte 0xb8
VARIABLE(grub_xnu_heap_start)
.long 0
.long 0
mov %rax, %rsi
/* mov imm32, %rcx */
.byte 0x48
.byte 0xb9
VARIABLE(grub_xnu_heap_size)
.long 0
.long 0
mov %rdi, %rax
add %rcx, %rax
/* %rax now contains our starting position after relocation. */
/* One more page to copy: ourselves. */
add $0x403, %rcx
shr $2, %rcx
/* Forward copy. */
cld
rep
movsl
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
/* Registers on XNU boot: eip, esp and eax. */
/* mov imm32, %ecx */
.byte 0xb9
VARIABLE (grub_xnu_entry_point)
.long 0
/* mov imm32, %eax */
.byte 0xb8
VARIABLE (grub_xnu_arg1)
.long 0
/* mov imm32, %ebx */
.byte 0xbb
VARIABLE (grub_xnu_stack)
.long 0
movl %ebx, %esp
jmp *%ecx
#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
VARIABLE(grub_xnu_launcher_end)