cc65/libsrc/c16/irq.s

;
; IRQ handling (C16 version)
;

	.export		initirq, doneirq
	.import		callirq

	.include	"plus4.inc"

; ------------------------------------------------------------------------

.segment	"INIT"

initirq:
	lda	IRQVec
	ldx	IRQVec+1
	sta	IRQInd+1
	stx	IRQInd+2
	lda	#<IRQStub
	ldx	#>IRQStub
	jmp	setvec

; ------------------------------------------------------------------------

.code

doneirq:
	lda	IRQInd+1
	ldx	IRQInd+2
setvec:	sei
	sta	IRQVec
	stx	IRQVec+1
	cli
	rts

; ------------------------------------------------------------------------

.segment	"LOWCODE"

IRQStub:
	cld				; Just to be sure
	jsr	callirq			; Call the functions
	jmp	IRQInd			; Jump to the saved IRQ vector

; ------------------------------------------------------------------------

.data

IRQInd:	jmp	$0000