grub/grub-core/kern/mips/startup.S
2010-08-23 21:50:38 +05:30

226 lines
4.8 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/offsets.h>
#include <grub/machine/memory.h>
#include <grub/offsets.h>
#define BASE_ADDR 8
.extern __bss_start
.extern _end
.globl __start, _start, start
__start:
_start:
start:
bal codestart
base:
. = _start + GRUB_KERNEL_MACHINE_COMPRESSED_SIZE
compressed_size:
.long 0
. = _start + GRUB_KERNEL_MACHINE_TOTAL_MODULE_SIZE
total_module_size:
.long 0
. = _start + GRUB_KERNEL_MACHINE_KERNEL_IMAGE_SIZE
kernel_image_size:
.long 0
codestart:
/* Save our base. */
move $s0, $ra
/* Parse arguments. Has to be done before relocation.
So need to do it in asm. */
#ifdef GRUB_MACHINE_MIPS_YEELOONG
move $s2, $zero
move $s3, $zero
move $s4, $zero
move $s5, $zero
/* $a2 has the environment. */
addiu $t0, $a2, 1
beq $t0, $zero, argdone
move $t0, $a2
argcont:
lw $t1, 0($t0)
beq $t1, $zero, argdone
#define DO_PARSE(str, reg) \
addiu $t2, $s0, (str-base);\
bal parsestr;\
beq $v0, $zero, 1f;\
move reg, $v0;\
b 2f;\
1:
DO_PARSE (busclockstr, $s2)
DO_PARSE (cpuclockstr, $s3)
DO_PARSE (memsizestr, $s4)
DO_PARSE (highmemsizestr, $s5)
2:
addiu $t0, $t0, 4
b argcont
parsestr:
move $v0, $zero
move $t3, $t1
3:
lb $t4, 0($t2)
lb $t5, 0($t3)
addiu $t2, $t2, 1
addiu $t3, $t3, 1
beq $t5, $zero, 1f
beq $t5, $t4, 3b
bne $t4, $zero, 1f
addiu $t3, $t3, 0xffff
digcont:
lb $t5, 0($t3)
/* Substract '0' from digit. */
addiu $t5, $t5, 0xffd0
bltz $t5, 1f
addiu $t4, $t5, 0xfff7
bgtz $t4, 1f
/* Multiply $v0 by 10 with bitshifts. */
sll $v0, $v0, 1
sll $t4, $v0, 2
addu $v0, $v0, $t4
addu $v0, $v0, $t5
addiu $t3, $t3, 1
b digcont
1:
jr $ra
busclockstr: .asciiz "busclock="
cpuclockstr: .asciiz "cpuclock="
memsizestr: .asciiz "memsize="
highmemsizestr: .asciiz "highmemsize="
.p2align 2
argdone:
#endif
/* Decompress the payload. */
addiu $a0, $s0, GRUB_KERNEL_MACHINE_RAW_SIZE - BASE_ADDR
lui $a1, %hi(compressed)
addiu $a1, %lo(compressed)
lw $a2, (GRUB_KERNEL_MACHINE_COMPRESSED_SIZE - BASE_ADDR)($s0)
move $s1, $a1
/* $a0 contains source compressed address, $a1 is destination,
$a2 is compressed size. FIXME: put LZMA here. Don't clober $s0,
$s1, $s2, $s3, $s4 and $s5.
On return $v0 contains uncompressed size.
*/
move $v0, $a2
reloccont:
lb $t4, 0($a0)
sb $t4, 0($a1)
addiu $a1,$a1,1
addiu $a0,$a0,1
addiu $a2, 0xffff
bne $a2, $0, reloccont
move $a0, $s1
move $a1, $v0
#include "cache_flush.S"
lui $t1, %hi(cont)
addiu $t1, %lo(cont)
jr $t1
. = _start + GRUB_KERNEL_MACHINE_RAW_SIZE
compressed:
. = _start + GRUB_KERNEL_MACHINE_PREFIX
VARIABLE(grub_prefix)
/* to be filled by grub-mkimage */
/*
* Leave some breathing room for the prefix.
*/
. = _start + GRUB_KERNEL_MACHINE_DATA_END
#ifdef GRUB_MACHINE_MIPS_YEELOONG
VARIABLE (grub_arch_busclock)
.long 0
VARIABLE (grub_arch_cpuclock)
.long 0
VARIABLE (grub_arch_memsize)
.long 0
VARIABLE (grub_arch_highmemsize)
.long 0
#endif
cont:
#ifdef GRUB_MACHINE_MIPS_YEELOONG
lui $t1, %hi(grub_arch_busclock)
addiu $t1, %lo(grub_arch_busclock)
sw $s2, 0($t1)
sw $s3, 4($t1)
sw $s4, 8($t1)
sw $s5, 12($t1)
#endif
/* Move the modules out of BSS. */
lui $t1, %hi(_start)
addiu $t1, %lo(_start)
lw $t2, (GRUB_KERNEL_MACHINE_KERNEL_IMAGE_SIZE - BASE_ADDR)($s0)
addu $t2, $t1, $t2
lui $t1, %hi(_end)
addiu $t1, %lo(_end)
addiu $t1, (GRUB_KERNEL_MACHINE_MOD_ALIGN-1)
li $t3, (GRUB_KERNEL_MACHINE_MOD_ALIGN-1)
nor $t3, $t3, $0
and $t1, $t1, $t3
lw $t3, (GRUB_KERNEL_MACHINE_TOTAL_MODULE_SIZE - BASE_ADDR)($s0)
/* 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)
jr $t1