; Support routines for the debugger
;
- .export _DbgInit
- .export _DbgSP, _DbgCS, _DbgHI
- .import popax, return0, _DbgEntry, _set_brk, _end_brk
- .import _DbgBreaks
- .import _brk_pc
+ .export _DbgInit
+ .export _DbgSP, _DbgCS, _DbgHI
+ .import popax, return0, _DbgEntry, _set_brk, _end_brk
+ .import _DbgBreaks
+ .import _brk_pc
.import __ZP_START__ ; Linker generated
.include "zeropage.inc"
; C callable function, will install the debugger
_DbgInit:
- lda #<DbgBreak
- ldx #>DbgBreak
- jmp _set_brk
+ lda #<DbgBreak
+ ldx #>DbgBreak
+ jmp _set_brk
; Entry for the break vector.
DbgBreak:
- pla
- sta retsav
- pla
- sta retsav+1
+ pla
+ sta retsav
+ pla
+ sta retsav+1
- cli
- tsx ; Stack pointer
- stx _DbgSP
+ cli
+ tsx ; Stack pointer
+ stx _DbgSP
- jsr DbgSwapZP ; Swap stuff
- lda #<DbgStack ; Set new stack
- sta sp
- lda #>DbgStack
- sta sp+1
- jsr ResetDbgBreaks ; Reset temporary breakpoints
- jsr _DbgEntry ; Call C code
- jsr SetDbgBreaks ; Set temporary breakpoints
- jsr DbgSwapZP ; Swap stuff back
+ jsr DbgSwapZP ; Swap stuff
+ lda #<DbgStack ; Set new stack
+ sta sp
+ lda #>DbgStack
+ sta sp+1
+ jsr ResetDbgBreaks ; Reset temporary breakpoints
+ jsr _DbgEntry ; Call C code
+ jsr SetDbgBreaks ; Set temporary breakpoints
+ jsr DbgSwapZP ; Swap stuff back
- lda retsav+1
- pha
- lda retsav
- pha
- rts
+ lda retsav+1
+ pha
+ lda retsav
+ pha
+ rts
; Stack used when in debugger mode
.bss
- .res 256
+ .res 256
DbgStack:
; Swap space for the the C temporaries
CTemp:
-_DbgCS: .res 2 ; sp
-_DbgHI: .res 2 ; sreg
- .res (zpsavespace-4) ; Other stuff
+_DbgCS: .res 2 ; sp
+_DbgHI: .res 2 ; sreg
+ .res (zpsavespace-4) ; Other stuff
-_DbgSP: .res 1
-retsav: .res 2 ; Save buffer for return address
+_DbgSP: .res 1
+retsav: .res 2 ; Save buffer for return address
.code
; Swap the C temporaries
DbgSwapZP:
- ldy #zpsavespace-1
-Swap1: ldx CTemp,y
- lda <__ZP_START__,y
- sta CTemp,y
- txa
- sta sp,y
- dey
- bpl Swap1
- rts
+ ldy #zpsavespace-1
+Swap1: ldx CTemp,y
+ lda <__ZP_START__,y
+ sta CTemp,y
+ txa
+ sta sp,y
+ dey
+ bpl Swap1
+ rts
; ----------------------------------------------------------------------------
; Utility functions
; reset the breakpoints. See declaration of struct breakpoint in the C
; source
-MaxBreaks = 48 ; 4*12
+MaxBreaks = 48 ; 4*12
ResetDbgBreaks:
- ldy #0
- ldx #0
-L4: lda _DbgBreaks+3,x ; Get bk_use
- beq L6 ; Jump if not set
- bpl L5 ; Jump if user breakpoint
- lda #0
- sta _DbgBreaks+3,x ; Clear if temp breakpoint
-L5: lda _DbgBreaks+1,x ; PC hi
- sta ptr1+1
- lda _DbgBreaks,x ; PC lo
- sta ptr1
- lda _DbgBreaks+2,x ; Old OPC
- sta (ptr1),y ; Reset the breakpoint
-L6: inx
- inx
- inx
- inx
- cpx #MaxBreaks ; Done?
- bne L4
- rts
+ ldy #0
+ ldx #0
+L4: lda _DbgBreaks+3,x ; Get bk_use
+ beq L6 ; Jump if not set
+ bpl L5 ; Jump if user breakpoint
+ lda #0
+ sta _DbgBreaks+3,x ; Clear if temp breakpoint
+L5: lda _DbgBreaks+1,x ; PC hi
+ sta ptr1+1
+ lda _DbgBreaks,x ; PC lo
+ sta ptr1
+ lda _DbgBreaks+2,x ; Old OPC
+ sta (ptr1),y ; Reset the breakpoint
+L6: inx
+ inx
+ inx
+ inx
+ cpx #MaxBreaks ; Done?
+ bne L4
+ rts
SetDbgBreaks:
- ldx #0
- ldy #0
-L7: lda _DbgBreaks+3,x ; Get bk_use
- beq L8 ; Jump if not set
- lda _DbgBreaks+1,x ; PC hi
- sta ptr1+1
- lda _DbgBreaks,x ; PC lo
- sta ptr1
- lda (ptr1),y ; Get the breakpoint OPC...
- sta _DbgBreaks+2,x ; ...and save it
- lda #$00 ; Load BRK opcode
- sta (ptr1),y
-L8: inx
- inx
- inx
- inx
- cpx #MaxBreaks ; Done?
- bne L7
- rts
+ ldx #0
+ ldy #0
+L7: lda _DbgBreaks+3,x ; Get bk_use
+ beq L8 ; Jump if not set
+ lda _DbgBreaks+1,x ; PC hi
+ sta ptr1+1
+ lda _DbgBreaks,x ; PC lo
+ sta ptr1
+ lda (ptr1),y ; Get the breakpoint OPC...
+ sta _DbgBreaks+2,x ; ...and save it
+ lda #$00 ; Load BRK opcode
+ sta (ptr1),y
+L8: inx
+ inx
+ inx
+ inx
+ cpx #MaxBreaks ; Done?
+ bne L7
+ rts
; Get a free breakpoint slot or return 0
- .export _DbgGetBreakSlot
+ .export _DbgGetBreakSlot
_DbgGetBreakSlot:
- ldx #0
-L10: lda _DbgBreaks+3,x ; Get bk_use
- beq L11 ; Jump if not set
- inx
- inx
- inx
- inx
- cpx #MaxBreaks ; Done?
- bne L10
- jmp return0 ; No free slot
-
-L11: stx tmp1
- lda #<_DbgBreaks
- ldx #>_DbgBreaks
- clc
- adc tmp1
- bcc L12
- inx
-L12: ldy #1 ; Force != 0
- rts
+ ldx #0
+L10: lda _DbgBreaks+3,x ; Get bk_use
+ beq L11 ; Jump if not set
+ inx
+ inx
+ inx
+ inx
+ cpx #MaxBreaks ; Done?
+ bne L10
+ jmp return0 ; No free slot
+
+L11: stx tmp1
+ lda #<_DbgBreaks
+ ldx #>_DbgBreaks
+ clc
+ adc tmp1
+ bcc L12
+ inx
+L12: ldy #1 ; Force != 0
+ rts
; Check if a given address has a user breakpoint set, if found, return the
; slot, otherwise return 0.
- .export _DbgIsBreak
+ .export _DbgIsBreak
_DbgIsBreak:
- jsr popax ; Get address
- sta ptr1
- stx ptr1+1
- ldx #0
-L20: lda _DbgBreaks+3,x ; Get bk_use
- beq L21 ; Jump if not set
- bmi L21 ; Jump if temp breakpoint
- lda _DbgBreaks,x ; Low byte of address
- cmp ptr1
- bne L21
- lda _DbgBreaks+1,x ; High byte of address
- cmp ptr1+1
- beq L22
-L21: inx
- inx
- inx
- inx
- cpx #MaxBreaks ; Done?
- bne L20
- jmp return0 ; Not found
-
-L22: stx tmp1
- lda #<_DbgBreaks
- ldx #>_DbgBreaks
- clc
- adc tmp1
- bcc L23
- inx
-L23: ldy #1 ; Force != 0
- rts
+ jsr popax ; Get address
+ sta ptr1
+ stx ptr1+1
+ ldx #0
+L20: lda _DbgBreaks+3,x ; Get bk_use
+ beq L21 ; Jump if not set
+ bmi L21 ; Jump if temp breakpoint
+ lda _DbgBreaks,x ; Low byte of address
+ cmp ptr1
+ bne L21
+ lda _DbgBreaks+1,x ; High byte of address
+ cmp ptr1+1
+ beq L22
+L21: inx
+ inx
+ inx
+ inx
+ cpx #MaxBreaks ; Done?
+ bne L20
+ jmp return0 ; Not found
+
+L22: stx tmp1
+ lda #<_DbgBreaks
+ ldx #>_DbgBreaks
+ clc
+ adc tmp1
+ bcc L23
+ inx
+L23: ldy #1 ; Force != 0
+ rts
projects / cc65 / blobdiff