CHR decompression

.macro ChrFile File, Address
  .word Address
  .local Start
  .local End
  .byt (End-Start)/128+1
Start:
  .incbin File
End:
.endmacro

.proc DecompressCHR
ChunksLeft = 3
  ; write pointer to info
  sta 0
  sty 1

  ldy #2
  lda (0),y
  sta ChunksLeft
  .repeat 2 ; write both parts of address
    dey
    lda (0),y
    sta PPUADDR
  .endrep

  ; move pointer to the actual data
  lda 0
  add #3
  sta ciSrc+0
  lda 1
  adc #0
  sta ciSrc+1

  lda #0
  sta ciBufStart
  lda #128
  sta ciBufEnd
ChunksLoop:
  jsr unpb53_some
  ldx #0
: lda PB53_outbuf,x
  sta PPUDATA
  inx
  cpx #128
  bne :-
  dec ChunksLeft
  bne ChunksLoop
  rts
.endproc