irq.s

minitos是一个实时的嵌入式操作系统

@	AREA	|subr|, CODE, READONLY

@            INCLUDE     aic.inc
#include "aic.h"

@;---------------------------------------------------------------------
@	EXPORT	    IRQ_Enter
@		;这里已经进入IRQ模式了，cpsr-->spsr,sp为IRQ的堆栈,lr为IRQ的lr_irq
@		;lr_irq=address of next Instruction to be execute + 4
@		;spsr_irq=CPSR
@		;cpsr[5]=0 arm mode
@		;cpsr[6] 不变
@		;cpsr[7]=1 
@		;pc=0x18
.text
	.align 4
	.global IRQ_Enter

IRQ_Enter:

	SUB	lr, lr, #4
	
	STMFD   sp!, {r0-r12, lr}       @; save registers
	
@        ldr     v1, =AIC_BASE
@	ldr	r0,[v1,#AIC_ISR] 
   	

@	IMPORT	IRQ_Handler
@	BL	IRQ_Handler	@;将IRQID作为参数传入
	
	BL	do_IRQ
	BL	IRQ_Shell	
@	IMPORT	IRQ_switch_task
	b	IRQ_switch_task

@	ldr         r0, =AIC_BASE
@	str         r0, [r0, #AIC_EOICR]
	LDMFD	sp!, {r0-r12, pc}^	@; Restore saved registers


@;------------------------------------------------------------------------------
@            EXPORT      at91spr


@at91spr:
@            sub         r14, r14, #4                
@            stmdb       r13!, {r14}                 
@            ldr         r14, =AIC_BASE              
@            str         r14, [r14, #AIC_EOICR]
@            ldmia       r13!, {pc}^                 

@		END