cc65/libsrc/atari/irq.s

;
; IRQ handling (ATARI version)
;

        .export         initirq, doneirq
        .import         callirq

        .include        "atari.inc"
.ifdef __ATARIXL__
        .import         __CHARGEN_START__
        .include        "romswitch.inc"
.endif

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

.segment        "ONCE"

initirq:
        lda     VVBLKD
        ldx     VVBLKD+1
        sta     IRQInd+1
        stx     IRQInd+2
        lda     #7
        ldy     #<IRQStub
        ldx     #>IRQStub
        jmp     SETVBV

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

.code

doneirq:
        lda     #7
        ldy     IRQInd+1
        ldx     IRQInd+2
        jmp     SETVBV

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

.segment        "LOWCODE"

IRQStub:
        cld                             ; Just to be sure
.ifdef __ATARIXL__
.ifdef CHARGEN_RELOC
        lda     CHBAS
        pha
.endif
        lda     PORTB
        pha
        and     #$FE
        sta     PORTB                   ; disable ROM
        set_chbase >__CHARGEN_START__
.endif
        jsr     callirq                 ; Call the functions
.ifdef __ATARIXL__
        pla
        sta     PORTB                   ; restore old ROM setting
.ifdef CHARGEN_RELOC
        pla
        sta     CHBAS
        sta     CHBASE
.endif
.endif
        jmp     IRQInd                  ; Jump to the saved IRQ vector

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

.data

IRQInd: jmp     $0000
Moved IRQ hooking / unhooking from startup code to constructor / destructor to avoid linking in the hooking / unhooking code (and callirq) for the majority of cc65 prorams not linking in interruptors. git-svn-id: svn://svn.cc65.org/cc65/trunk@5985 b7a2c559-68d2-44c3-8de9-860c34a00d81 2013-02-12 22:39:38 +00:00			`;`
			`; IRQ handling (ATARI version)`
			`;`

Removed (pretty inconsistently used) tab chars from source code base. 2013-05-09 11:56:54 +00:00			`.export initirq, doneirq`
			`.import callirq`
Moved IRQ hooking / unhooking from startup code to constructor / destructor to avoid linking in the hooking / unhooking code (and callirq) for the majority of cc65 prorams not linking in interruptors. git-svn-id: svn://svn.cc65.org/cc65/trunk@5985 b7a2c559-68d2-44c3-8de9-860c34a00d81 2013-02-12 22:39:38 +00:00
Removed (pretty inconsistently used) tab chars from source code base. 2013-05-09 11:56:54 +00:00			`.include "atari.inc"`
adapt to CHARGEN_RELOC 2013-09-20 16:09:53 +00:00			`.ifdef __ATARIXL__`
			`.import __CHARGEN_START__`
			`.include "romswitch.inc"`
			`.endif`
Moved IRQ hooking / unhooking from startup code to constructor / destructor to avoid linking in the hooking / unhooking code (and callirq) for the majority of cc65 prorams not linking in interruptors. git-svn-id: svn://svn.cc65.org/cc65/trunk@5985 b7a2c559-68d2-44c3-8de9-860c34a00d81 2013-02-12 22:39:38 +00:00
			`; ------------------------------------------------------------------------`

Renamed INITBSS to INIT and INIT to ONCE. The way we want to use the INITBSS segment - and especially the fact that it won't have the type bss on all ROM based targets - means that the name INITBSS is misleading. After all INIT is the best name from my perspective as it serves several purposes and therefore needs a rather generic name. Unfortunately this means that the current INIT segment needs to be renamed too. Looking for a short (ideally 4 letter) name I came up with ONCE as it contains all code (and data) accessed only once during initialization. 2016-03-06 20:26:22 +00:00			`.segment "ONCE"`
Moved IRQ hooking / unhooking from startup code to constructor / destructor to avoid linking in the hooking / unhooking code (and callirq) for the majority of cc65 prorams not linking in interruptors. git-svn-id: svn://svn.cc65.org/cc65/trunk@5985 b7a2c559-68d2-44c3-8de9-860c34a00d81 2013-02-12 22:39:38 +00:00
			`initirq:`
Use deferred VBI instead of immediate VBI. A deferred VBI won't be called if the user program has interrupts disabled which makes it easier to avoid race conditions. 2014-01-02 20:45:12 +00:00			`lda VVBLKD`
			`ldx VVBLKD+1`
Removed (pretty inconsistently used) tab chars from source code base. 2013-05-09 11:56:54 +00:00			`sta IRQInd+1`
			`stx IRQInd+2`
Use deferred VBI instead of immediate VBI. A deferred VBI won't be called if the user program has interrupts disabled which makes it easier to avoid race conditions. 2014-01-02 20:45:12 +00:00			`lda #7`
Removed (pretty inconsistently used) tab chars from source code base. 2013-05-09 11:56:54 +00:00			`ldy #<IRQStub`
			`ldx #>IRQStub`
small optimization 2014-05-26 23:49:35 +00:00			`jmp SETVBV`
Moved IRQ hooking / unhooking from startup code to constructor / destructor to avoid linking in the hooking / unhooking code (and callirq) for the majority of cc65 prorams not linking in interruptors. git-svn-id: svn://svn.cc65.org/cc65/trunk@5985 b7a2c559-68d2-44c3-8de9-860c34a00d81 2013-02-12 22:39:38 +00:00
			`; ------------------------------------------------------------------------`

			`.code`

			`doneirq:`
Use deferred VBI instead of immediate VBI. A deferred VBI won't be called if the user program has interrupts disabled which makes it easier to avoid race conditions. 2014-01-02 20:45:12 +00:00			`lda #7`
Removed (pretty inconsistently used) tab chars from source code base. 2013-05-09 11:56:54 +00:00			`ldy IRQInd+1`
			`ldx IRQInd+2`
small optimization 2014-05-26 23:49:35 +00:00			`jmp SETVBV`
Moved IRQ hooking / unhooking from startup code to constructor / destructor to avoid linking in the hooking / unhooking code (and callirq) for the majority of cc65 prorams not linking in interruptors. git-svn-id: svn://svn.cc65.org/cc65/trunk@5985 b7a2c559-68d2-44c3-8de9-860c34a00d81 2013-02-12 22:39:38 +00:00
			`; ------------------------------------------------------------------------`

Removed (pretty inconsistently used) tab chars from source code base. 2013-05-09 11:56:54 +00:00			`.segment "LOWCODE"`
Moved IRQ hooking / unhooking from startup code to constructor / destructor to avoid linking in the hooking / unhooking code (and callirq) for the majority of cc65 prorams not linking in interruptors. git-svn-id: svn://svn.cc65.org/cc65/trunk@5985 b7a2c559-68d2-44c3-8de9-860c34a00d81 2013-02-12 22:39:38 +00:00
			`IRQStub:`
Removed (pretty inconsistently used) tab chars from source code base. 2013-05-09 11:56:54 +00:00			`cld ; Just to be sure`
Use '.ifdef' and '.ifndef' instead of '.if .defined' and '.if .not .defined'. 2013-09-19 20:36:22 +00:00			`.ifdef __ATARIXL__`
adapt to CHARGEN_RELOC 2013-09-20 16:09:53 +00:00			`.ifdef CHARGEN_RELOC`
			`lda CHBAS`
			`pha`
			`.endif`
			`lda PORTB`
			`pha`
Some formatting and style fixes. 2013-10-01 09:32:08 +00:00			`and #$FE`
adapt to CHARGEN_RELOC 2013-09-20 16:09:53 +00:00			`sta PORTB ; disable ROM`
			`set_chbase >__CHARGEN_START__`
atarixl target: add support for interruptors, adapt TGI drivers 2013-08-25 09:20:27 +00:00			`.endif`
Removed (pretty inconsistently used) tab chars from source code base. 2013-05-09 11:56:54 +00:00			`jsr callirq ; Call the functions`
Use '.ifdef' and '.ifndef' instead of '.if .defined' and '.if .not .defined'. 2013-09-19 20:36:22 +00:00			`.ifdef __ATARIXL__`
adapt to CHARGEN_RELOC 2013-09-20 16:09:53 +00:00			`pla`
			`sta PORTB ; restore old ROM setting`
			`.ifdef CHARGEN_RELOC`
			`pla`
			`sta CHBAS`
			`sta CHBASE`
			`.endif`
atarixl target: add support for interruptors, adapt TGI drivers 2013-08-25 09:20:27 +00:00			`.endif`
Removed (pretty inconsistently used) tab chars from source code base. 2013-05-09 11:56:54 +00:00			`jmp IRQInd ; Jump to the saved IRQ vector`
Moved IRQ hooking / unhooking from startup code to constructor / destructor to avoid linking in the hooking / unhooking code (and callirq) for the majority of cc65 prorams not linking in interruptors. git-svn-id: svn://svn.cc65.org/cc65/trunk@5985 b7a2c559-68d2-44c3-8de9-860c34a00d81 2013-02-12 22:39:38 +00:00
			`; ------------------------------------------------------------------------`

			`.data`

Removed (pretty inconsistently used) tab chars from source code base. 2013-05-09 11:56:54 +00:00			`IRQInd: jmp $0000`