mirror of
https://github.com/sehugg/8bitworkshop.git
synced 2024-12-27 14:29:39 +00:00
417 lines
12 KiB
Plaintext
417 lines
12 KiB
Plaintext
|
|
;
|
|
; LZ4FH uncompression for 6502
|
|
; By Andy McFadden
|
|
; Version 1.0.1, August 2015
|
|
;
|
|
; Refactored for size & speed
|
|
; by Peter Ferrie.
|
|
;
|
|
; Developed with Merlin-16
|
|
; Ported to DASM by Steven Hugg
|
|
; Apache 2.0 license
|
|
; http://www.apache.org/licenses/LICENSE-2.0
|
|
;
|
|
|
|
processor 6502
|
|
|
|
org $0803
|
|
|
|
;
|
|
; Constants
|
|
;
|
|
lz4fh_magic equ $66 ;ascii 'f'
|
|
tok_empty equ 253
|
|
tok_eod equ 254
|
|
|
|
;
|
|
; Variable storage
|
|
;
|
|
srcptr equ $3c ;2b a1l
|
|
dstptr equ $3e ;2b a1h
|
|
copyptr equ $00 ;2b
|
|
savmix equ $02 ;1b
|
|
savlen equ $03 ;1b
|
|
|
|
;
|
|
; ROM routines
|
|
;
|
|
bell equ $ff3a
|
|
monitor equ $ff69
|
|
|
|
entry
|
|
sta $c050
|
|
sta $c052
|
|
sta $c057
|
|
jsr ClrScr
|
|
jsr UnpackLZ4FH
|
|
.endless
|
|
jmp .endless
|
|
|
|
|
|
UnpackLZ4FH:
|
|
lda #<LZDATA ;copy source address to zero page
|
|
sta srcptr
|
|
lda #>LZDATA
|
|
sta srcptr+1
|
|
lda #0 ;copy destination address to zero page
|
|
sta dstptr
|
|
lda #$20
|
|
sta dstptr+1
|
|
sta _desthi+1
|
|
|
|
ldy #$00
|
|
lda (srcptr),y
|
|
cmp #lz4fh_magic ;does magic match?
|
|
beq goodmagic
|
|
|
|
fail
|
|
jsr bell
|
|
jmp monitor
|
|
|
|
; These stubs increment the high byte and then jump
|
|
; back. This saves a cycle because branch-not-taken
|
|
; becomes the common case. We assume that we're not
|
|
; unpacking data at $FFxx, so BNE is branch-always.
|
|
hi2
|
|
inc srcptr+1
|
|
bne nohi2
|
|
|
|
hi3
|
|
inc srcptr+1
|
|
clc
|
|
bcc nohi3
|
|
|
|
hi4
|
|
inc dstptr+1
|
|
bne nohi4
|
|
|
|
notempty
|
|
cmp #tok_eod
|
|
bne fail
|
|
rts ;success!
|
|
|
|
; handle "special" match values (value in A)
|
|
specialmatch
|
|
cmp #tok_empty
|
|
bne notempty
|
|
|
|
tya ;empty match, advance srcptr
|
|
adc srcptr ; past and jump to main loop
|
|
sta srcptr
|
|
bcc mainloop
|
|
inc srcptr+1
|
|
bne mainloop
|
|
|
|
hi5
|
|
inc srcptr+1
|
|
clc
|
|
bcc nohi5
|
|
|
|
goodmagic
|
|
inc srcptr
|
|
bne mainloop
|
|
inc srcptr+1
|
|
|
|
mainloop
|
|
; Get the mixed-length byte and handle the literal.
|
|
ldy #$00
|
|
lda (srcptr),y ;get mixed-length byte
|
|
sta savmix
|
|
lsr ;get the literal length
|
|
lsr
|
|
lsr
|
|
lsr
|
|
beq noliteral
|
|
cmp #$0f ;sets carry for >= 15
|
|
bne shortlit
|
|
|
|
inc srcptr
|
|
beq hi2
|
|
nohi2
|
|
lda (srcptr),y ;get length extension
|
|
adc #14 ;(carry set) add 15 - will not exceed 255
|
|
|
|
; at this point, srcptr holds the address of the "mix"
|
|
; word or the length extension, and dstptr holds the
|
|
; address of the next output location. So we want to
|
|
; read from (srcptr),y+1 and write to (dstptr),y.
|
|
; we can do this by sticking the DEY between the LDa
|
|
; and STa.
|
|
;
|
|
; We could save a couple of cycles by substituting
|
|
; addr,y in place of (dp),y, but the added setup cost
|
|
; would only benefit longer literal strings.
|
|
shortlit tax
|
|
tay
|
|
.litloop
|
|
lda (srcptr),y ;5
|
|
dey ;2 if len is 255, copy 0-254
|
|
sta (dstptr),y ;6
|
|
bne .litloop ;3 -> 16 cycles/byte
|
|
|
|
; advance srcptr by savlen+1, and dstptr by savlen
|
|
txa
|
|
sec ;this gets us the +1
|
|
adc srcptr
|
|
sta srcptr
|
|
bcs hi3
|
|
nohi3 ;carry cleared by hi3
|
|
txa
|
|
adc dstptr
|
|
sta dstptr
|
|
bcs hi4
|
|
nohi4
|
|
dey ;Y=0; DEY so next INY goes to 0
|
|
|
|
; Handle match. Y holds an offset into srcptr such
|
|
; that we need to increment it once to get the next
|
|
; interesting byte.
|
|
noliteral
|
|
lda savmix
|
|
and #$0f
|
|
cmp #$0f
|
|
bcc .shortmatch ;BCC
|
|
|
|
iny
|
|
lda (srcptr),y ;get length extension
|
|
cmp #237 ;"normal" values are 0-236
|
|
bcs specialmatch ;BCS
|
|
adc #15 ;will not exceed 255
|
|
|
|
; Put the destination address into copyptr.
|
|
.shortmatch
|
|
adc #4 ;min match; won't exceed 255
|
|
sta savlen ;save match len for later
|
|
tax ;and keep it in X
|
|
iny
|
|
lda (srcptr),y ;match offset, lo
|
|
sta copyptr
|
|
iny
|
|
lda (srcptr),y ;match offset, hi
|
|
_desthi ora #$00 ;OR in hi-res page
|
|
sta copyptr+1
|
|
|
|
; advance srcptr past the encoded match while we still
|
|
; remember how many bytes it took to encode. Y is
|
|
; indexing the last value used, so we want to go
|
|
; advance srcptr by Y+1.
|
|
|
|
tya
|
|
sec
|
|
adc srcptr
|
|
sta srcptr
|
|
bcs hi5
|
|
nohi5 ;hi5 clears carry
|
|
|
|
; Copy the match. The length is in X. Note this
|
|
; must be a forward copy so overlapped data works.
|
|
;
|
|
; We know the match is at least 4 bytes long, so
|
|
; we could save a few cycles by not doing the
|
|
; aDC #4 earlier, and unrolling the first 4
|
|
; load/store operations here.
|
|
ldy #$00
|
|
.copyloop
|
|
lda (copyptr),y ;5
|
|
sta (dstptr),y ;6
|
|
iny ;2
|
|
dex ;2
|
|
bne .copyloop ;3 -> 18 cycles/byte
|
|
|
|
; advance dstptr past copied data
|
|
lda dstptr
|
|
adc savlen ;carry is clear
|
|
sta dstptr
|
|
bcc mainloop
|
|
inc dstptr+1
|
|
bne mainloop ;always (not unpacking at $FFxx)
|
|
|
|
ClrScr:
|
|
lda #$20
|
|
sta .clrloop+2
|
|
ldy #0
|
|
lda #0
|
|
.clrloop sta $2000,y
|
|
iny
|
|
bne .clrloop
|
|
inc .clrloop+2
|
|
ldx .clrloop+2
|
|
cpx #$40
|
|
bne .clrloop
|
|
rts
|
|
|
|
LZDATA:
|
|
; WORLDMAP file
|
|
hex 661f7f1400002001002900b040014019
|
|
hex 0000007c000008290041030600032a00
|
|
hex 43065433002900980000403f00002603
|
|
hex 0059005102000000202a000668000249
|
|
hex 002f0100128100134080001536770011
|
|
hex 042900213c6429001a0f9f006760004b
|
|
hex 0000025900536000000008e2002f3066
|
|
hex 27740025043c5900170ca30083106040
|
|
hex 1370472102a5005a1000000018810014
|
|
hex 0357014f0600071c2674005844780300
|
|
hex 007800140ce0004510000004a3005a20
|
|
hex 781f0030810014017f003f0818000e73
|
|
hex 00430c003010350137700106a2000958
|
|
hex 00576003044003f201420a607c0fa600
|
|
hex 121e290017059d000a2c020875001030
|
|
hex 6e0134000e075900617c7f01007c0157
|
|
hex 011306590010222c005a0e0c20030c9a
|
|
hex 002270063d021220400192030c000440
|
|
hex 01000660d90008ad021b30d8010f0176
|
|
hex 00f2031e18400100400700067f1f6a38
|
|
hex 0c4001000f630150387e00002c0c034a
|
|
hex 39005000810022700f3f0014014a005f
|
|
hex 604001000c017e004f330000600ceb02
|
|
hex 2400042c026230005c1b00422802162c
|
|
hex 49002d1f0380001403bc0113082a021f
|
|
hex 401580000f2178005001006000403800
|
|
hex 133e5601223e029b02477805541fa100
|
|
hex 6f7e03007e0702425a002a3200b10021
|
|
hex 204428001a079f007a30004e00000208
|
|
hex 6d0204ea002f1c22267400260e06ad02
|
|
hex 04ea000141016830003f647c204c013a
|
|
hex 1000005a00190885030f1077002d7001
|
|
hex 9c0029047cdc0104c404762038007031
|
|
hex 0006cb012c0e30570523016080002f78
|
|
hex 0f0ef20153381800781fb50037304003
|
|
hex a20019092e024702040001f201750e40
|
|
hex 1738004001c3002770079d002f400105
|
|
hex 6902581f0000637109027702407b7f07
|
|
hex 0010c304aa3360034001023860000e9a
|
|
hex 00130f210212234001210206cd021a02
|
|
hex d8000440050a9b000f01770012707f00
|
|
hex a37c71004f2008400040014803401e00
|
|
hex 00070c031d332c034630060006c20412
|
|
hex 404c001f08017e001f3e0ee802340660
|
|
hex 07a700621800761e004e7b0016244900
|
|
hex 5c0703011800d90124003cc2032f4001
|
|
hex 4ccc0311402c04210c03c40012303606
|
|
hex 22000cec052a7400a10038380f0a5900
|
|
hex 110691030348030f2973001c13b00424
|
|
hex 7c01b500431e704301a6007a10004c01
|
|
hex 0000049d00130c6b001f0627f3043a0a
|
|
hex 030c300513303f057f10006e07002006
|
|
hex 094d05140cb3001f021373004d401f7f
|
|
hex 019d051a0cb303250001330535730f03
|
|
hex a3006a6003600018009b001f3017e903
|
|
hex 537830037801350136607101a2002a40
|
|
hex 0d59001706df006200001c0033604e00
|
|
hex 0288022850015c060f06e80267010060
|
|
hex 3f5f038103857f466a7d0d001000d800
|
|
hex ba4013205e4101037840010e81002518
|
|
hex 3c9e0200e3022f420307cd061f1810e8
|
|
hex 0634400107df00523078410070d10060
|
|
hex 40471f0000034f001d132c0346600700
|
|
hex 0cd60212604c004f180040011fd60373
|
|
hex 40073000400118c20343460300789a07
|
|
hex 151e4a005a0e420108039b0045030000
|
|
hex 68c2071f004fcc074240134004750002
|
|
hex 72080367054a481b0700a10038000e08
|
|
hex 590014045501000c030f2973002a1100
|
|
hex b100246001b40044701b1066cd083a18
|
|
hex 0000d80805d70c4f4000000227f30436
|
|
hex 3b010cb30a02d10804e10a5766050020
|
|
hex 044d011c3059051f04186a097f607f7f
|
|
hex 417f00400b9c09044c0902e700451e78
|
|
hex 0160cc095a00400008006b021f1007e9
|
|
hex 021c1c2e0b4460030e0f350d205b0310
|
|
hex 0603ce090aad06560606600300c00242
|
|
hex 140020204e0002580018589c091f6009
|
|
hex 680a45010f037c58006966434f3a6d39
|
|
hex 970a8c19307e4001014000ac0a227020
|
|
hex 49001223e100226300cd020f01d3061f
|
|
hex 0c11e80324410fdf0280103c41001c00
|
|
hex 7e016900137f4b004c200f6071810012
|
|
hex 04980b2418783a096f40010010004020
|
|
hex d50382600c1f0000077c1f900723043a
|
|
hex c30235016c1f4a00241e42ef0508b503
|
|
hex 234007d10c1f604dcb0b00e805101653
|
|
hex 0a1570240a0367013a685101a0002c38
|
|
hex 3006020336001340640e0f2477003a40
|
|
hex 1104b1002238033401644003100c1027
|
|
hex cd084d0f000003b0071f062feb0c1725
|
|
hex ac0a17303a0d5a300840630f4a0d1c20
|
|
hex 5905140633010f107205933f00784118
|
|
hex 007041038e071403a6051a005b10255e
|
|
hex 013301560c40006001a5105f070c0040
|
|
hex 0114dc0d2a76012e0200390a14073501
|
|
hex 01ad06102e2d004a03003c0e310f3704
|
|
hex 700f3f0e303c0020a50605bd0c186cdb
|
|
hex 001f2006e8021107290d2506065f0786
|
|
hex 0f583f0f60007000d800321f103ea70e
|
|
hex 2a1c009a0018273e0a40003f00001703
|
|
hex 1f0400d3062f300410e8032438479c02
|
|
hex 901c1c644101060003011e06133a4b00
|
|
hex 4e300b30012e0f01a70033704f0f5101
|
|
hex 0027132f006020d50382266c0100002f
|
|
hex 3c70d10823042e590026314821065d3c
|
|
hex 5e007818b00723000c3a091f204dcb0b
|
|
hex 1178470e560320000400c80311100f06
|
|
hex 2a7300a0002a6e388100150867104f01
|
|
hex 0040702774003a601807b100237c0145
|
|
hex 066306101c506101ce0900e7100acf03
|
|
hex 23010071091f0129f1083567010b5900
|
|
hex 17203a0d8f607f1f0378066006094d11
|
|
hex 1302ea012f40010e7300406001004e22
|
|
hex 0f137f58002f4c0701a6115638007833
|
|
hex 01b3004640072001a5002a0404fe0a2f
|
|
hex 001c06e902393803073103775e61637e
|
|
hex 037f01d702aa403b0040016002600700
|
|
hex 0702370c071f3f0e31680020d7143260
|
|
hex 677daa000759001f2007e70201210270
|
|
hex 6a037c07001c003d1292180e106c0c40
|
|
hex 036001520e70601f00007c300ea70e4a
|
|
hex 030138008100192c71024f7301000804
|
|
hex cf123f600c0e0fe903246c44db04e37e
|
|
hex 040c000102004101001860033e4b003d
|
|
hex 700a1880004506000003340d13184803
|
|
hex 2f38301fd503307c3f361006023c0242
|
|
hex 10000c66290036033f0c210a5e287000
|
|
hex 7870b0131338c0020f4eca1300571430
|
|
hex 3440011b0f069902121c9f120a9f003a
|
|
hex 404f28a911181867141f582774003a20
|
|
hex 7801b1001236380364037e0c187070cc
|
|
hex 1116306d1106780023600362012f0432
|
|
hex 2674003946410ddd00240018b5066710
|
|
hex 0040074003cd180f0758150f0ff20121
|
|
hex 7c0332182340738b02147da515190631
|
|
hex 0323000ce805022b1636072003a50058
|
|
hex 3c0700000f5c021f0605690220406f2e
|
|
hex 0d163d3403517347637f01c504160836
|
|
hex 0379400130062003007800471848055c
|
|
hex bf0231580130cd0231387c4728001812
|
|
hex 5b161f100b6816f3040e00000c703f00
|
|
hex 1c780770030630587c030660cd08613c
|
|
hex 700300602fa6124a4701280081003728
|
|
hex 7003a300511e01000841d0121d039700
|
|
hex 1f0810e803244747c600606f7c180001
|
|
hex 03210f440e70011c4703131fa0170a5b
|
|
hex 002406003a0d130c6c0c2f6f1f1fd503
|
|
hex 1106591a232006650804701948062c64
|
|
hex 0122142a60438000140167001f6050c8
|
|
hex 1313002c1808b3002f783f0241182a40
|
|
hex 69d602173067102f604c2774003a3c28
|
|
hex 00b1001203400177406319184021034d
|
|
hex 013a080002db011530610d1f1627f418
|
|
hex 2a61069e001708e00d07ca010e551114
|
|
hex 032c022f08700ff201430403601fd10c
|
|
hex 64707f03007818a5001a02ae19053c02
|
|
hex 1103c20023201ea5005906000078012b
|
|
hex 0a3f4000020569022060063801263f03
|
|
hex 5e0146076307011b1200510410018b0b
|
|
hex 490420070c7800577058044006c00221
|
|
hex 0118cd02410c70010306030f135b1a14
|
|
hex 040c0ad0130e0007007c1c7e7f215e3b
|
|
hex 0e3c0612786c01500e407f793ca70e3d
|
|
hex 6d00780406277e017c0032010078cf1a
|
|
hex 0d80000030001f300d6b031406ac0662
|
|
hex 6039403c0003a81d157849003f401706
|
|
hex 012d1b1504340d1f0628cc0331030013
|
|
hex c21821000cbc0c130c711536047c6621
|
|
hex 0a005a062c0343b1031a006a000f1500
|
|
hex 000ffe
|
|
|