rockbox/firmware/target/mips/ingenic_jz47xx/crt0.S
Maurus Cuelenaere b632ddf9ca And set svn:eol-style ...
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@18034 a1c6a512-1295-4272-9138-f99709370657
2008-07-14 15:19:29 +00:00

246 lines
7.4 KiB
ArmAsm

/*
* init.S
*
* Initialization code for JzRISC.
*
* Author: Seeger Chin
* e-mail: seeger.chin@gmail.com
*
* Copyright (C) 2006 Ingenic Semiconductor Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include "config.h"
#include "mips.h"
.text
.set mips3
.extern main
.global _start
#ifdef BOOTLOADER
.section .init.text,"ax",%progbits
#else
.section .resetvectors,"ax",%progbits
#endif
.set noreorder
.set noat
#ifdef BOOTLOADER
.word 0 /* HACK */
.word 0 /* HACK */
#endif
_start:
la ra, _start
//----------------------------------------------------
// init cp0 registers.
//----------------------------------------------------
mtc0 zero, C0_WATCHLO
mtc0 zero, C0_WATCHHI
li t0, (M_StatusBEV | M_StatusIM7 | M_StatusIM6 \
| M_StatusIM5 | M_StatusIM4 | M_StatusIM3 \
| M_StatusIM2 | M_StatusERL)
// BEV = Enable Boot Exception Vectors
// IMx = Interrupt mask
// ERL = Denotes error level
mtc0 t0, C0_STATUS
li t1, M_CauseIV
mtc0 t1, C0_CAUSE
//----------------------------------------------------
// init caches, assumes a 4way*128set*32byte i/d cache
//----------------------------------------------------
li t0, 3 // enable cache for kseg0 accesses
mtc0 t0, C0_CONFIG // CONFIG reg
la t0, 0x80000000 // an idx op should use a unmappable address
ori t1, t0, 0x4000 // 16kB cache
mtc0 zero, C0_TAGLO // TAGLO reg
mtc0 zero, C0_TAGHI // TAGHI reg
_init_cache_loop:
cache 0x8, 0(t0) // index store icache tag
cache 0x9, 0(t0) // index store dcache tag
bne t0, t1, _init_cache_loop
addiu t0, t0, 0x20 // 32 bytes per cache line
nop
//----------------------------------------------------
// Invalidate BTB
//----------------------------------------------------
mfc0 t0, C0_CONFIG
nop
ori t0, 2
mtc0 t0, C0_CONFIG
nop
//----------------------------------------------------
// setup stack, jump to C code
//----------------------------------------------------
la sp, stackend
la t0, stackbegin
li t1, 0xDEADBEEF
_init_stack_loop:
sw t1, 0(t0)
bne t0, sp, _init_stack_loop
addiu t0, t0, 4
la t0, main
jr t0
nop
#ifndef BOOTLOADER
.section .vectors,"ax",%progbits
#endif
.extern exception_handler
.global except_common_entry
.type except_common_entry,@function
except_common_entry:
la k0, exception_handler
jr k0
nop
nop
nop
.extern _int
.extern _exception
.global exception_handler
.type exception_handler,@function
.set noreorder
exception_handler:
addiu sp, -0x80 # Add Immediate Unsigned
sw ra, 0(sp) # Store Word
sw fp, 4(sp) # Store Word
sw gp, 8(sp) # Store Word
sw t9, 0xC(sp) # Store Word
sw t8, 0x10(sp) # Store Word
sw s7, 0x14(sp) # Store Word
sw s6, 0x18(sp) # Store Word
sw s5, 0x1C(sp) # Store Word
sw s4, 0x20(sp) # Store Word
sw s3, 0x24(sp) # Store Word
sw s2, 0x28(sp) # Store Word
sw s1, 0x2C(sp) # Store Word
sw s0, 0x30(sp) # Store Word
sw t7, 0x34(sp) # Store Word
sw t6, 0x38(sp) # Store Word
sw t5, 0x3C(sp) # Store Word
sw t4, 0x40(sp) # Store Word
sw t3, 0x44(sp) # Store Word
sw t2, 0x48(sp) # Store Word
sw t1, 0x4C(sp) # Store Word
sw t0, 0x50(sp) # Store Word
sw a3, 0x54(sp) # Store Word
sw a2, 0x58(sp) # Store Word
sw a1, 0x5C(sp) # Store Word
sw a0, 0x60(sp) # Store Word
sw v1, 0x64(sp) # Store Word
sw v0, 0x68(sp) # Store Word
sw $1, 0x6C(sp) # Store Word
mflo t0 # Move F LO
nop
sw t0, 0x70(sp) # Store Word
mfhi t0 # Move F HI
nop
sw t0, 0x74(sp) # Store Word
mfc0 t0, C0_STATUS # Status register
sll zero, 1 # Shift Left Logical
sll zero, 1 # Shift Left Logical
sll zero, 1 # Shift Left Logical
sll zero, 1 # Shift Left Logical
sw t0, 0x78(sp) # Store Word
mfc0 t0, C0_EPC # Exception Program Counter
sll zero, 1 # Shift Left Logical
sll zero, 1 # Shift Left Logical
sll zero, 1 # Shift Left Logical
sll zero, 1 # Shift Left Logical
sw t0, 0x7C(sp) # Store Word
li k1, 0x7C # Load Immediate
mfc0 k0, C0_CAUSE # C0_CAUSE of last exception
and k0, k1 # AND
beq zero, k0, _int # Branch on Equal
nop
la k0, _exception
jr k0
nop
.global _int
.type _int,@function
_int:
jal intr_handler # Jump And Link
nop
lw ra, 0(sp) # Load Word
lw fp, 4(sp) # Load Word
sw gp, 8(sp) # Store Word
lw t9, 0xC(sp) # Load Word
lw t8, 0x10(sp) # Load Word
lw s7, 0x14(sp) # Load Word
lw s6, 0x18(sp) # Load Word
lw s5, 0x1C(sp) # Load Word
lw s4, 0x20(sp) # Load Word
lw s3, 0x24(sp) # Load Word
lw s2, 0x28(sp) # Load Word
lw s1, 0x2C(sp) # Load Word
lw s0, 0x30(sp) # Load Word
lw t7, 0x34(sp) # Load Word
lw t6, 0x38(sp) # Load Word
lw t5, 0x3C(sp) # Load Word
lw t4, 0x40(sp) # Load Word
lw t3, 0x44(sp) # Load Word
lw t2, 0x48(sp) # Load Word
lw t1, 0x4C(sp) # Load Word
lw t0, 0x50(sp) # Load Word
lw a3, 0x54(sp) # Load Word
lw a2, 0x58(sp) # Load Word
lw a1, 0x5C(sp) # Load Word
lw a0, 0x60(sp) # Load Word
lw v1, 0x64(sp) # Load Word
lw v0, 0x68(sp) # Load Word
lw v1, 0x6C(sp) # Load Word
lw k0, 0x70(sp) # Load Word
mtlo k0 # Move To LO
nop
lw k0, 0x74(sp) # Load Word
mthi k0 # Move To HI
nop
lw k0, 0x78(sp) # Load Word
nop
mtc0 k0, C0_STATUS # Status register
sll zero, 1 # Shift Left Logical
sll zero, 1 # Shift Left Logical
sll zero, 1 # Shift Left Logical
sll zero, 1 # Shift Left Logical
lw k0, 0x7C(sp) # Load Word
nop
mtc0 k0, C0_EPC # Exception Program Counter
sll zero, 1 # Shift Left Logical
sll zero, 1 # Shift Left Logical
sll zero, 1 # Shift Left Logical
sll zero, 1 # Shift Left Logical
addiu sp, 0x80 # Add Immediate Unsigned
eret # Exception Return
nop
.extern _except_handler
.global _exception
.type _exception,@function
_exception:
move a0, sp
mfc0 a1, C0_CAUSE # C0_CAUSE of last exception
mfc0 a2, C0_EPC # Exception Program Counter
la k0, except_handler # Load Address
jr k0 # Jump Register
nop
.set reorder