New module fileio-test.c

[cc65] / libsrc / c64 / break.s

diff --git a/libsrc/c64/break.s b/libsrc/c64/break.s
index 8b90d4fb51a51e6584a5738023554d16b54bf3fb..76315b7b961ea9222671a7b031ccaebc917c4160 100644 (file)
--- a/libsrc/c64/break.s
+++ b/libsrc/c64/break.s
@@ -6,24 +6,24 @@
 ;
 
                .export         _set_brk, _reset_brk
+       .destructor     _reset_brk
                .export         _brk_a, _brk_x, _brk_y, _brk_sr, _brk_pc
-       .import         _atexit
 
        .include        "c64.inc"
 
 
 .bss
-_brk_a:                .res    1
-_brk_x:                .res    1
-_brk_y:                .res    1
-_brk_sr:       .res    1
-_brk_pc:       .res    2
+_brk_a:                .res    1
+_brk_x:                .res    1
+_brk_y:                .res    1
+_brk_sr:       .res    1
+_brk_pc:       .res    2
 
 oldvec:        .res    2               ; Old vector
 
 
 .data
-uservec:       jmp     $FFFF           ; Patched at runtime
+uservec:       jmp     $FFFF           ; Patched at runtime
 
 
 .code
@@ -31,26 +31,22 @@ uservec:            jmp     $FFFF           ; Patched at runtime
 ; Set the break vector
 .proc  _set_brk
 
-       sta     uservec+1
-       stx     uservec+2       ; Set the user vector
+       sta     uservec+1
+       stx     uservec+2       ; Set the user vector
 
-       lda     oldvec
-       ora     oldvec+1        ; Did we save the vector already?
-               bne     L1              ; Jump if we installed the handler already
+       lda     oldvec
+       ora     oldvec+1        ; Did we save the vector already?
+               bne     L1              ; Jump if we installed the handler already
 
-       lda     BRKVec
+       lda     BRKVec
        sta     oldvec
-       lda     BRKVec+1
-       sta     oldvec+1        ; Save the old vector
+       lda     BRKVec+1
+       sta     oldvec+1        ; Save the old vector
 
-       lda     #<_reset_brk
-       ldx     #>_reset_brk
-       jsr     _atexit         ; Install an exit handler
-
-L1:    lda     #<brk_handler   ; Set the break vector to our routine
-       sta     BRKVec
-       lda     #>brk_handler
-       sta     BRKVec+1
+L1:    lda     #<brk_handler   ; Set the break vector to our routine
+       ldx     #>brk_handler
+       sta     BRKVec
+       stx     BRKVec+1
        rts
 
 .endproc
@@ -59,11 +55,15 @@ L1: lda     #<brk_handler   ; Set the break vector to our routine
 ; Reset the break vector
 .proc  _reset_brk
 
-       lda     oldvec
-       sta     BRKVec
-       lda     oldvec+1
-       sta     BRKVec+1
-       rts
+       lda     oldvec
+       ldx     oldvec+1
+       beq     @L9             ; Jump if vector not installed
+       sta     BRKVec
+       stx     BRKVec+1
+       lda     #$00
+       sta     oldvec          ; Clear the old vector
+       stx     oldvec+1
+@L9:   rts
 
 .endproc