132 lines
1.8 KiB
ArmAsm
132 lines
1.8 KiB
ArmAsm
;; printf()-like routine for simplifying debugging
|
|
|
|
;; Prints the literal zero-terminated string that follows,
|
|
;; which may also include special tokens that allow
|
|
;; printing of hex byte and word values stored at the indicated
|
|
;; addresses.
|
|
|
|
printf:
|
|
;; Temporary storage is between end of screen at $0400
|
|
;; and the sprite pointers at $7f8
|
|
sta $7f0
|
|
stx $7f1
|
|
sty $7f2
|
|
php
|
|
pla
|
|
sta $7f3
|
|
|
|
;; Set up read routine
|
|
lda #$ad ; LDA $nnnn
|
|
sta $7f4
|
|
lda #$60
|
|
sta $7f7 ; RTS
|
|
|
|
;; Get PC of caller from the stack, so that
|
|
;; we can parse through it
|
|
pla
|
|
clc
|
|
adc #$01
|
|
sta $7f5
|
|
pla
|
|
adc #$00
|
|
sta $7f6
|
|
|
|
printf_loop:
|
|
jsr $7f4
|
|
cmp #$00
|
|
bne printf_continues
|
|
;; Put return address on stack and restore
|
|
;; registers
|
|
lda $7f6
|
|
pha
|
|
lda $7f5
|
|
pha
|
|
lda $7f3
|
|
pha
|
|
lda $7f0
|
|
ldx $7f1
|
|
ldy $7f2
|
|
plp
|
|
rts
|
|
|
|
printf_continues:
|
|
cmp #$01
|
|
bne not_hexbyte
|
|
;; Print a hex byte
|
|
|
|
;; Skip the token
|
|
jsr printf_advance
|
|
;; Read the low byte
|
|
jsr $7f4
|
|
;; Print as hex
|
|
jsr printf_printhexbyte
|
|
jmp printf_nextchar
|
|
|
|
not_hexbyte:
|
|
cmp #$02
|
|
bne not_hexword
|
|
;; Print a hex word
|
|
|
|
;; Skip the token
|
|
jsr printf_advance
|
|
jsr printf_advance
|
|
;; Read the high byte
|
|
jsr $7f4
|
|
;; Print as hex
|
|
jsr printf_printhexbyte
|
|
;; Skip the token
|
|
jsr printf_retreat
|
|
;; Read the low byte
|
|
jsr $7f4
|
|
;; Print as hex
|
|
jsr printf_printhexbyte
|
|
jsr printf_advance
|
|
jmp printf_nextchar
|
|
|
|
not_hexword:
|
|
;; Print character
|
|
jsr $ffd2
|
|
|
|
printf_nextchar:
|
|
jsr printf_advance
|
|
|
|
jmp printf_loop
|
|
|
|
printf_advance:
|
|
;; Advance pointer to next character
|
|
inc $7f5
|
|
bne +
|
|
inc $7f6
|
|
*
|
|
rts
|
|
|
|
printf_retreat:
|
|
;; Retreat pointer to previous char
|
|
lda $7f5
|
|
sec
|
|
sbc #1
|
|
sta $7f5
|
|
lda $7f6
|
|
sbc #0
|
|
sta $7f6
|
|
rts
|
|
|
|
printf_printhexbyte:
|
|
pha
|
|
lsr
|
|
lsr
|
|
lsr
|
|
lsr
|
|
ora #$30
|
|
cmp #$3A
|
|
bcc +
|
|
adc #6
|
|
* jsr $ffd2
|
|
pla
|
|
and #$0f
|
|
ora #$30
|
|
cmp #$3A
|
|
bcc +
|
|
adc #6
|
|
* jmp $ffd2
|