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/*
* File : start_gcc.S
* This file is part of RT-Thread RTOS
* COPYRIGHT (C) 2006 - 2011, RT-Thread Development Team
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rt-thread.org/license/LICENSE
*
* Change Logs:
* Date Author Notes
* 2010-05-17 swkyer first version
* 2010-09-04 bernard porting to Jz47xx
*/
#include "../common/mips.inc"
#include "../common/stackframe.h"
.section ".start", "ax"
.set noreorder
/* the program entry */
.globl _start
_start:
.set noreorder
la ra, _start
/* disable interrupt */
mfc0 t0, CP0_STATUS
and t0, 0xfffffffe # By default it will be disabled.
mtc0 t0, CP0_STATUS # Set CPU to disable interrupt.
nop
/* disable cache */
mfc0 t0, CP0_CONFIG
and t0, 0xfffffff8
or t0, 0x2 # disable,!default value is not it!
mtc0 t0, CP0_CONFIG # Set CPU to disable cache.
nop
/* setup stack pointer */
li sp, SYSTEM_STACK
la gp, _gp
/* clear bss */
la t0, __bss_start
la t1, __bss_end
_clr_bss_loop:
sw zero, 0(t0)
bne t0, t1, _clr_bss_loop
addiu t0, t0, 4
/* jump to RT-Thread RTOS */
jal rtthread_startup
nop
/* restart, never die */
j _start
nop
.set reorder
.globl cp0_get_cause
cp0_get_cause:
mfc0 v0, CP0_CAUSE
jr ra
nop
.globl cp0_get_status
cp0_get_status:
mfc0 v0, CP0_STATUS
jr ra
nop
.globl cp0_get_hi
cp0_get_hi:
mfhi v0
jr ra
nop
.globl cp0_get_lo
cp0_get_lo:
mflo v0
jr ra
nop
.extern tlb_refill_handler
.extern cache_error_handler
/* Exception Handler */
/* 0x0 - TLB refill handler */
.section .vectors.1, "ax", %progbits
.global tlb_refill_exception
.type tlb_refill_exception,@function
tlb_refill_exception:
j tlb_refill_handler
nop
/* 0x100 - Cache error handler */
.section .vectors.2, "ax", %progbits
j cache_error_handler
nop
/* 0x180 - Exception/Interrupt handler */
.section .vectors.3, "ax", %progbits
.global general_exception
.type general_exception,@function
general_exception:
j _general_exception_handler
nop
/* 0x200 - Special Exception Interrupt handler (when IV is set in CP0_CAUSE) */
.section .vectors.4, "ax", %progbits
.global irq_exception
.type irq_exception,@function
irq_exception:
j _irq_handler
nop
.section .vectors, "ax", %progbits
.extern mips_irq_handle
/* general exception handler */
_general_exception_handler:
.set noreorder
la k0, mips_irq_handle
jr k0
nop
.set reorder
/* interrupt handler */
_irq_handler:
.set noreorder
la k0, mips_irq_handle
jr k0
nop
.set reorder
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