Fixed the break stuff

git-svn-id: svn://svn.cc65.org/cc65/trunk@1593 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/plus4/break.s

@@ -6,8 +6,8 @@
 ;
 
        	.export	   	_set_brk, _reset_brk
-	.destructor	_reset_brk
 	.export	       	_brk_a, _brk_x, _brk_y, _brk_sr, _brk_pc
+        .import         brk_jmp
 
 	.include      	"plus4.inc"
 
@@ -19,11 +19,11 @@ _brk_y:		.res   	1
 _brk_sr:	.res	1
 _brk_pc:	.res	2
 
-oldvec:       	.res	2   		; Old vector
+oldvec:       	.res	2      	   	; Old vector
 
 
 .data
-uservec:    	jmp	$FFFF		; Patched at runtime
+uservec:    	jmp	$FFFF  	   	; Patched at runtime
 
 
 .code
@@ -32,21 +32,12 @@ uservec:    	jmp	$FFFF		; Patched at runtime
 .proc	_set_brk
 
 	sta	uservec+1
-  	stx	uservec+2 	; Set the user vector
+  	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	BRKVec
- 	sta    	oldvec
- 	lda 	BRKVec+1
- 	sta	oldvec+1	; Save the old vector
-
-L1:	lda	#<brk_handler	; Set the break vector to our routine
-	ldx	#>brk_handler
-	sta	BRKVec
-	stx	BRKVec+1
+        lda	#<brk_handler  	; Set the break vector to our routine
+	sta	brk_jmp+1
+       	lda	#>brk_handler
+	sta	brk_jmp+2
 	rts
 
 .endproc
@@ -55,26 +46,20 @@ L1:	lda	#<brk_handler	; Set the break vector to our routine
 ; Reset the break vector
 .proc	_reset_brk
 
-	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
+        lda     #$00
+        sta     brk_jmp+1
+        sta     brk_jmp+2       ; Reset the vector
+        rts
 
 .endproc
 
 
 
-; Break handler, called if a break occurs
+; Break handler, called if a break occurs. Note: Y is not on the stack!
 
 .proc	brk_handler
 
-	pla
-	sta	_brk_y
+       	sty	_brk_y
 	pla
 	sta	_brk_x
 	pla