X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=libsrc%2Fc128%2Fbreak.s;h=f2f872be87d00430c54b892e88abd209e45d099e;hb=f16516047a551319c82debd339ded8bc2b587212;hp=6f4cfe42059eed8c697da9a520e6c1fbaf049f52;hpb=e02b3e91c8f30d4553a03eefc610497b973d99f2;p=cc65

diff --git a/libsrc/c128/break.s b/libsrc/c128/break.s
index 6f4cfe420..f2f872be8 100644
--- a/libsrc/c128/break.s
+++ b/libsrc/c128/break.s
@@ -5,74 +5,69 @@
 ; void reset_brk (void);
 ;
 
-       	.export	    	_set_brk, _reset_brk
-	.destructor	_reset_brk
-  	.export	    	_brk_a, _brk_x, _brk_y, _brk_sr, _brk_pc
-  	.importzp	ptr1
+        .export         _set_brk, _reset_brk
+        .destructor     _reset_brk
+        .export         _brk_a, _brk_x, _brk_y, _brk_sr, _brk_pc
+        .importzp       ptr1
 
-  	.include    	"c128.inc"
+        .include        "c128.inc"
 
 
 .bss
-_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
-
+_brk_a:         .res    1
+_brk_x:         .res    1
+_brk_y:         .res    1
+_brk_sr:        .res    1
+_brk_pc:        .res    2
 
 .data
-uservec:    	jmp 	$FFFF		; Patched at runtime
+uservec:        jmp     $FFFF           ; Patched at runtime
 
 .code
 
-; Where will we put the break stub?
-stub_addr	= $0E00			; BASIC sprite area
-
-
 
 ; Set the break vector
-.proc	_set_brk
+.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    	L2    	      	; Jump if we installed the handler already
+        lda     brk_old+1
+        ora     brk_old+2       ; 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
+        lda     BRKVec          ; Save the old vector
+        sta     brk_old+1
+        lda     BRKVec+1
+        sta     brk_old+2
 
-   	ldy	#stub_size-1	; Copy our stub into the low mem area
-L1:	lda	brk_stub,y
-	sta	stub_addr,y
-	dey
-	bpl	L1
+        lda     #<brk_stub      ; Set the break vector to our stub
+        ldx     #>brk_stub
+        sta     BRKVec
+        stx     BRKVec+1
 
-L2:    	lda    	#<stub_addr 	; Set the break vector to our stub
-  	sta	BRKVec
-  	lda	#>stub_addr
-  	sta	BRKVec+1
-  	rts
+        lda     #<brk_handler   ; Set the indirect vector to our handler
+        ldx     #>brk_handler
+        sta     brk_ind+1
+        stx     brk_ind+2
+
+@L1:    rts
 
 .endproc
 
 
 ; Reset the break vector
-.proc	_reset_brk
-
-	lda  	oldvec
-	bne  	@L1
-	ldx  	oldvec
-	beq  	@L9		; Jump if vector not installed
-@L1:	sta    	BRKVec
-	stx  	BRKVec+1
-@L9:	rts
+.proc   _reset_brk
+
+        lda     brk_old+1
+        ldx     brk_old+2
+        beq     @L9             ; Jump if vector not installed
+        sta     BRKVec
+        stx     BRKVec+1
+        lda     #$00
+        sta     brk_old+1       ; Clear the saved vector
+        sta     brk_old+2
+@L9:    rts
 
 .endproc
 
@@ -80,46 +75,61 @@ L2:    	lda    	#<stub_addr 	; Set the break vector to our stub
 
 ; Break handler, called if a break occurs
 
-.proc	brk_handler
-
-	pla
-	sta	_brk_y
-	pla
-	sta	_brk_x
-	pla
-	sta	_brk_a
-	pla
-	and	#$EF	 	; Clear break bit
-	sta	_brk_sr
-	pla	      	 	; PC low
-	sec
-	sbc	#2 	 	; Point to start of brk
-	sta	_brk_pc
-	pla	    	 	; PC high
-	sbc	#0
-	sta	_brk_pc+1
-
-       	jsr	uservec	 	; Call the user's routine
-
-	lda	_brk_pc+1
-	pha
-	lda	_brk_pc
-	pha
-	lda	_brk_sr
-	pha
-	ldx    	_brk_x
-	ldy	_brk_y
-	lda	_brk_a
-	rti	   		; Jump back...
+.proc   brk_handler
+
+        pla
+        sta     _brk_y
+        pla
+        sta     _brk_x
+        pla
+        sta     _brk_a
+        pla
+        and     #$EF            ; Clear break bit
+        sta     _brk_sr
+        pla                     ; PC low
+        sec
+        sbc     #2              ; Point to start of brk
+        sta     _brk_pc
+        pla                     ; PC high
+        sbc     #0
+        sta     _brk_pc+1
+
+        jsr     uservec         ; Call the user's routine
+
+        lda     _brk_pc+1
+        pha
+        lda     _brk_pc
+        pha
+        lda     _brk_sr
+        pha
+        ldx     _brk_x
+        ldy     _brk_y
+        lda     _brk_a
+        rti                     ; Jump back...
+
+.endproc
+
+
+; Break stub, must go into low (non banked) memory
+
+.segment        "LOWCODE"
 
+.proc   brk_stub
+        pla                             ; Get original MMU_CR value
+        sta     MMU_CR                  ; And set it
+        jmp     brk_ind                 ; Jump indirect to break
 .endproc
 
+; ------------------------------------------------------------------------
+; Data
+
+.data
+
+; Old break vector preceeded by a jump opcode
+brk_old:
+        jmp     $0000
 
-brk_stub:
-	.org	stub_addr
-       	pla			; Get original MMU value
-	sta	MMU_CR		; Re-enable our config
-	jmp	brk_handler	; Jump to the user handler
-	.reloc
+; Indirect vectors preceeded by a jump opcode
+brk_ind:
+        jmp     $0000
 
-stub_size	= * - brk_stub