interruptor support by Stefan Haubenthal

git-svn-id: svn://svn.cc65.org/cc65/trunk@5055 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/libsrc/atari/crt0.s b/libsrc/atari/crt0.s
index 53caf0e4c5a3f317ec3f78a1b61e7e03260f4e9a..4542d8945ecd89d891711a64fb225628fd2c7b45 100644 (file)
--- a/libsrc/atari/crt0.s
+++ b/libsrc/atari/crt0.s
@@ -5,18 +5,19 @@
 ;      Mark Keates
 ;      Freddy Offenga
 ;      Christian Groessler
+;      Stefan Haubenthal
 ;
 
        .export         _exit
-        .export         __STARTUP__ : absolute = 1      ; Mark as startup
+       .export         __STARTUP__ : absolute = 1      ; Mark as startup
 
-       .import         initlib, donelib, callmain
-               .import         zerobss, pushax
-       .import         _main, __filetab, getfd
+       .import         initlib, donelib
+       .import         callmain, zerobss, callirq
+       .import         __INTERRUPTOR_COUNT__
        .import         __STARTUP_LOAD__, __ZPSAVE_LOAD__
        .import         __RESERVED_MEMORY__
 
-        .include        "zeropage.inc"
+       .include        "zeropage.inc"
        .include        "atari.inc"
 
 ; ------------------------------------------------------------------------
@@ -41,7 +42,7 @@
 
 ; Save the zero page locations we need
 
-               ldx     #zpspace-1
+       ldx     #zpspace-1
 L1:    lda     sp,x
        sta     zpsave,x
        dex
@@ -51,12 +52,12 @@ L1: lda     sp,x
 
        jsr     zerobss
 
-; setup the stack
+; Setup the stack
 
        tsx
        stx     spsave
 
-; report memory usage
+; Report memory usage
 
        lda     APPMHI
        sta     appmsav                 ; remember old APPMHI value
@@ -73,18 +74,31 @@ L1: lda     sp,x
        sta     APPMHI+1
        sta     sp+1                    ; setup runtime stack part 2
 
+; If we have IRQ functions, chain our stub into the IRQ vector
+
+       lda     #<__INTERRUPTOR_COUNT__
+       beq     NoIRQ1
+       lda     VVBLKI
+       ldx     VVBLKI+1
+       sta     IRQInd+1
+       stx     IRQInd+2
+       lda     #6
+       ldy     #<IRQStub
+       ldx     #>IRQStub
+       jsr     SETVBV
+
 ; Call module constructors
 
-       jsr     initlib
+NoIRQ1:        jsr     initlib
 
-; set left margin to 0
+; Set left margin to 0
 
        lda     LMARGN
        sta     old_lmargin
        ldy     #0
        sty     LMARGN
 
-; set keyb to upper/lowercase mode
+; Set keyb to upper/lowercase mode
 
        ldx     SHFLOK
        stx     old_shflok
@@ -92,7 +106,7 @@ L1:  lda     sp,x
 
 ; Initialize conio stuff
 
-       dey                             ; Set X to $FF
+       dey                             ; Set X to $FF
        sty     CH
 
 ; Push arguments and call main
@@ -103,22 +117,32 @@ L1:       lda     sp,x
 
 _exit: jsr     donelib         ; Run module destructors
 
+; Reset the IRQ vector if we chained it.
+
+       pha                     ; Save the return code on stack
+       lda     #<__INTERRUPTOR_COUNT__
+       beq     NoIRQ2
+       lda     #6
+       ldy     IRQInd+1
+       ldx     IRQInd+2
+       jsr     SETVBV
+
 ; Restore system stuff
 
-       ldx     spsave
-       txs                     ; Restore stack pointer
+NoIRQ2:        ldx     spsave
+       txs                     ; Restore stack pointer
 
-; restore left margin
+; Restore left margin
 
        lda     old_lmargin
        sta     LMARGN
 
-; restore kb mode
+; Restore kb mode
 
        lda     old_shflok
        sta     SHFLOK
 
-; restore APPMHI
+; Restore APPMHI
 
        lda     appmsav
        sta     APPMHI
@@ -133,7 +157,7 @@ L2: lda     zpsave,x
        dex
        bpl     L2
 
-; turn on cursor
+; Turn on cursor
 
        inx
        stx     CRSINH
@@ -142,11 +166,26 @@ L2:       lda     zpsave,x
 
        rts
 
+; ------------------------------------------------------------------------
+; 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
+
+IRQInd: jmp    $0000
+
 ; *** end of main startup code
 
-.segment        "ZPSAVE"
+.segment       "ZPSAVE"
 
-zpsave:        .res    zpspace
+zpsave: .res   zpspace
 
        .bss