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Add interrupt handling code from Stefan Haubenthal

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git-svn-id: svn://svn.cc65.org/cc65/trunk@3264 b7a2c559-68d2-44c3-8de9-860c34a00d81
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cuz 2004-10-26 19:44:30 +00:00
parent b74f658b93
commit 463712217c
1 changed files with 42 additions and 6 deletions
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46
libsrc/vic20/crt0.s
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@ -5,15 +5,15 @@
;
.export _exit
.import initlib, donelib
.import initlib, donelib, callirq
.import zerobss, push0
.import callmain
.import RESTOR, BSOUT, CLRCH
.import __IRQFUNC_COUNT__
.import __RAM_START__, __RAM_SIZE__ ; Linker generated
.include "zeropage.inc"
.include "vic20.inc"
.include "../cbm/cbm.inc"
; ------------------------------------------------------------------------
; Place the startup code in a special segment.
@ -70,14 +70,41 @@ L1: lda sp,x
jsr initlib
; If we have IRQ functions, chain our stub into the IRQ vector
lda #<__IRQFUNC_COUNT__
beq NoIRQ1
lda IRQVec
ldx IRQVec+1
sta IRQInd+1
stx IRQInd+2
lda #<IRQStub
ldx #>IRQStub
sei
sta IRQVec
stx IRQVec+1
cli
; Push arguments and call main()
jsr callmain
NoIRQ1: jsr callmain
; Call module destructors. This is also the _exit entry.
; Back from main (This is also the _exit entry). Reset the IRQ vector if we
; chained it.
_exit: pha ; Save the return code on stack
jsr donelib ; Run module destructors
lda #<__IRQFUNC_COUNT__
beq NoIRQ2
lda IRQInd+1
ldx IRQInd+2
sei
sta IRQVec
stx IRQVec+1
cli
; Run module destructors
NoIRQ2: jsr donelib
; Copy back the zero page stuff
@ -102,12 +129,21 @@ L2: lda zpsave,x
jmp RESTOR
; ------------------------------------------------------------------------
; The IRQ vector jumps here, if condes routines are defined with type 2.
IRQStub:
cld ; Just to be sure
jsr callirq ; Call the functions
jmp IRQInd ; Jump to the saved IRQ vector
; ------------------------------------------------------------------------
; Data
.data
zpsave: .res zpspace
IRQInd: jmp $0000
.bss