interrupts.s

来自「专业汽车级嵌入式操作系统OSEK的源代码」· S 代码 · 共 62 行

@  This is the init for an AT91SAM7
@ This code is entered with interrupts disabled
@ This code should work as start code from flash or RAM.
@ It does not have to be placed at address 0 since it will copy the vectors
@ there if needed.
@
	.text
	.code 32
	.align 	0
	
	.global interrupts_get_and_disable
	.global interrupts_enable
	.global fiq_get_and_disable
	.global fiq_enable


@ int interrupts_get_and_disable
@  Disables interrupts. 
@ Returns zero if interupts were previously off

interrupts_get_and_disable:
		mrs	r0, cpsr
		ands    r0, r0, #0x80
		movne   r0, #0
		bxne    lr
		mrs	r0, cpsr
		orr	r0,r0,#0x80
		msr	cpsr_c,r0
		mov     r0,#1
		bx	lr

@ void interrupts_enable
interrupts_enable:
		mrs	r0, cpsr
		bic	r0,r0,#0x80
		msr	cpsr_c,r0
		bx	lr


@ int fiq_get_and_disable
@  Disables interrupts. 
@ Returns zero if interupts were previously off

fiq_get_and_disable:
		mrs	r0, cpsr
		ands    r0, r0, #0x40
		movne   r0, #0
		bxne    lr
		mrs	r0, cpsr
		orr	r0,r0,#0x80
		msr	cpsr_c,r0
		mov     r0,#1
		bx	lr

@ void fiq_enable
fiq_enable:
		mrs	r0, cpsr
		bic	r0,r0,#0x40
		msr	cpsr_c,r0
		bx	lr