63 lines
1.9 KiB
ArmAsm
63 lines
1.9 KiB
ArmAsm
; -------------------------------------------------------------------
|
|
; this file is intended to be assembled and linked with the cc65 toolchain.
|
|
; It has not been tested with any other assemblers or linkers.
|
|
; -------------------------------------------------------------------
|
|
; -------------------------------------------------------------------
|
|
; example usage do the stream decruncher
|
|
; this program decrunches data to memory
|
|
; -------------------------------------------------------------------
|
|
.import init_decruncher
|
|
.import get_decrunched_byte
|
|
.export get_crunched_byte
|
|
|
|
.export buffer_start_hi: absolute
|
|
.export buffer_len_hi: absolute
|
|
|
|
.byte $01,$08,$0b,$08,<2003,>2003,$9e,'2','0','6','1',0,0,0
|
|
; -------------------------------------------------------------------
|
|
; we begin here
|
|
; -------------------------------------------------------------------
|
|
lda $04
|
|
sta _byte_lo
|
|
lda $05
|
|
sta _byte_hi
|
|
jsr init_decruncher
|
|
_sample_next:
|
|
jsr get_decrunched_byte
|
|
bcs _sample_end
|
|
;; do whatever you wish with the value in the accumulator
|
|
ldx store_lo
|
|
bne skip_store_dec_hi
|
|
dec store_hi
|
|
skip_store_dec_hi:
|
|
dec store_lo
|
|
store_lo = * + 1
|
|
store_hi = * + 2
|
|
.byte $8d, 0, 0 ;sta $0000
|
|
|
|
jmp _sample_next
|
|
_sample_end:
|
|
rts
|
|
; -------------------------------------------------------------------
|
|
; for this get_crunched_byte routine to work the crunched data has to be
|
|
; crunched using the -m <buffersize> and possibly the -l flags. Any other
|
|
; flag will just mess things up.
|
|
get_crunched_byte:
|
|
lda _byte_lo
|
|
bne _byte_skip_hi
|
|
dec _byte_hi
|
|
_byte_skip_hi:
|
|
dec _byte_lo
|
|
_byte_lo = * + 1
|
|
_byte_hi = * + 2
|
|
lda $ffff ; needs to be set correctly before
|
|
rts ; decrunch_file is called.
|
|
; end_of_data needs to point to the address just after the address
|
|
; of the last byte of crunched data.
|
|
; -------------------------------------------------------------------
|
|
buffer_len_hi = 4 ; 1k
|
|
unaligned_buffer:
|
|
.res (buffer_len_hi * 256) + 255
|
|
buffer_start_hi = (unaligned_buffer + 255) / 256
|
|
|