grub/kern/mips/startup.S
2009-10-18 16:10:42 +02:00

125 lines
2.9 KiB
ArmAsm

/* startup.S - Startup code for the MIPS. */
/*
* 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>
#include <grub/cpu/kernel.h>
#include <grub/machine/memory.h>
#define BASE_ADDR 8
.extern __bss_start
.extern _end
.globl __start, _start, start
__start:
_start:
start:
bal codestart
. = _start + GRUB_KERNEL_CPU_COMPRESSED_SIZE
compressed_size:
.long 0
. = _start + GRUB_KERNEL_CPU_TOTAL_MODULE_SIZE
total_module_size:
.long 0
. = _start + GRUB_KERNEL_CPU_KERNEL_IMAGE_SIZE
kernel_image_size:
.long 0
codestart:
/* Decompress the payload. */
addiu $t2, $ra, GRUB_KERNEL_CPU_RAW_SIZE - BASE_ADDR
lui $t1, %hi(compressed)
addiu $t1, %lo(compressed)
lw $t3, (GRUB_KERNEL_CPU_COMPRESSED_SIZE - BASE_ADDR)($ra)
/* $t2 contains source compressed address, $t1 is destination,
$t3 is compressed size. FIXME: put LZMA here. Don't clober $ra
*/
reloccont:
lb $t4, 0($t2)
sb $t4, 0($t1)
addiu $t1,$t1,1
addiu $t2,$t2,1
addiu $t3, 0xffff
bne $t3, $0, reloccont
/* Move the modules out of BSS. */
lui $t1, %hi(_start)
addiu $t1, %lo(_start)
lw $t2, (GRUB_KERNEL_CPU_KERNEL_IMAGE_SIZE - BASE_ADDR)($ra)
addu $t2, $t1, $t2
lui $t1, %hi(_end)
addiu $t1, %lo(_end)
addiu $t1, (GRUB_MOD_ALIGN-1)
li $t3, (GRUB_MOD_ALIGN-1)
nor $t3, $t3, $0
and $t1, $t1, $t3
/* Pass modules address as first argument. */
// move $a0, $t1
lw $t3, (GRUB_KERNEL_CPU_TOTAL_MODULE_SIZE - BASE_ADDR)($ra)
/* Backward copy. */
add $t1, $t1, $t3
add $t2, $t2, $t3
addiu $t1, $t1, 0xffff
addiu $t2, $t2, 0xffff
/* $t2 is source. $t1 is destination. $t3 is size. */
modulesmovcont:
lb $t4, 0($t2)
sb $t4, 0($t1)
addiu $t1,$t1,0xffff
addiu $t2,$t2,0xffff
addiu $t3, 0xffff
bne $t3, $0, modulesmovcont
/* Clean BSS. */
lui $t1, %hi(__bss_start)
addiu $t1, %lo(__bss_start)
lui $t2, %hi(_end)
addiu $t2, %lo(_end)
bsscont:
sb $0,0($t1)
addiu $t1,$t1,1
sltu $t3,$t1,$t2
bne $t3, $0, bsscont
li $sp, GRUB_MACHINE_MEMORY_STACK_HIGH
lui $t1, %hi(grub_main)
addiu $t1, %lo(grub_main)
#if __mips >= 2
sync
#endif
jr $t1
. = _start + GRUB_KERNEL_CPU_RAW_SIZE
compressed:
. = _start + GRUB_KERNEL_CPU_PREFIX
VARIABLE(grub_prefix)
/* to be filled by grub-mkelfimage */
/*
* Leave some breathing room for the prefix.
*/
. = _start + GRUB_KERNEL_CPU_DATA_END