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Defendit numerus
Join Date: Mar 2017
Location: Crossing the Rubicon
Age: 54
Posts: 4,491
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Quote:
Originally Posted by roondar
Sounds good, where can I find the source for cruncher/decruncher?  |
http://eab.abime.net/showpost.php?p=...2&postcount=18
I do not find the nrv2r, but I'm pretty sure I've posted it somewhere, so here the generic one, extract the version you need:
Code:
; nrv2x decoder in pure 68k asm for Rygar AGA
; On entry:
; a0 buffer start
; d0 offset inside buffer for packed data
; On exit:
; buffer filled with unpacked data
; all registers preserved
nrv2x_decoder:
movem.l d0-d5/a0-a4,-(sp)
move.l d0,d3
lea (a0),a1
adda.l d0,a0
; common setup
moveq #-$80,d0
moveq #-1,d2
moveq #2,d4
moveq #-2,d5
; select between s/r algorithms
tst.l d3
beq.w nrv2r_unpack
; nrv2s decompression in pure 68k asm
; by ross
;
; On entry:
; a0 src packed data pointer
; a1 dest pointer
; (decompress from a0 to a1)
;
; On exit:
; a0 = dest start
; a1 = dest end
;
; Register usage:
; a2 m_pos
; a3 constant: -$d00
; a4 2nd src pointer (in stack)
;
; d0 bit buffer
; d1 m_off
; d2 m_len or -1
;
; d3 last_m_off
; d4 constant: 2
; d5 reserved space on stack (max 256)
;
;
; Notes:
; we have max_offset = 2^23, so we can use some word arithmetics on d1
; we have max_match = 65535, so we can use word arithmetics on d2
;
nrv2s_unpack
; movem.l d0-d5/a1-a4,-(sp)
move.b (a0)+,d1 ; ~stack usage
; moveq #-2,d5
and.b d1,d5
lea (sp),a4
adda.l d5,sp ; reserve space
._stk move.b (a0)+,-(a4)
addq.b #1,d1
bne.b ._stk
; ------------- setup constants -----------
; moveq #-$80,d0 ; d0.b = $80 (byte refill flag)
; moveq #-1,d2
moveq #-1,d3 ; last_off = -1
; moveq #2,d4
movea.w #-$d00,a3
; ------------- DECOMPRESSION -------------
.decompr_literal
move.b (a0)+,(a1)+
.decompr_loop
add.b d0,d0
bcc.b .decompr_match
bne.b .decompr_literal
move.b (a0)+,d0
addx.b d0,d0
bcs.b .decompr_literal
.decompr_match
moveq #-2,d1
.decompr_gamma_1
add.b d0,d0
bne.b ._g_1
move.b (a0)+,d0
addx.b d0,d0
._g_1 addx.w d1,d1 ; max 2^23!
add.b d0,d0
bcc.b .decompr_gamma_1
bne.b .decompr_select
move.b (a0)+,d0
addx.b d0,d0
bcc.b .decompr_gamma_1
.decompr_select
addq.w #3,d1
beq.b .decompr_get_mlen ; last m_off
bpl.b .decompr_exit_token
lsl.l #8,d1
move.b (a0)+,d1
move.l d1,d3 ; last_m_off = m_off
.decompr_get_mlen ; implicit d2 = -1
add.b d0,d0
bne.b ._e_1
move.b (a0)+,d0
addx.b d0,d0
._e_1 addx.w d2,d2
add.b d0,d0
bne.b ._e_2
move.b (a0)+,d0
addx.b d0,d0
._e_2 addx.w d2,d2
lea (a1,d3.l),a2
addq.w #2,d2
bgt.b .decompr_gamma_2
.decompr_tiny_mlen
move.l d3,d1
sub.l a3,d1
addx.w d4,d2
.L_copy2 move.b (a2)+,(a1)+
.L_copy1 move.b (a2)+,(a1)+
dbra d2,.L_copy1
.L_rep bra.b .decompr_loop
.decompr_gamma_2 ; implicit d2 = 1
add.b d0,d0
bne.b ._g_2
move.b (a0)+,d0
addx.b d0,d0
._g_2 addx.w d2,d2
add.b d0,d0
bcc.b .decompr_gamma_2
bne.b .decompr_large_mlen
move.b (a0)+,d0
addx.b d0,d0
bcc.b .decompr_gamma_2
.decompr_large_mlen
move.b (a2)+,(a1)+
move.b (a2)+,(a1)+
cmp.l a3,d3
bcs.b .L_copy2
move.b (a2)+,(a1)+
dbra d2,.L_copy1
.decompr_exit_token
lea (a4),a0
bclr d2,d2 ; ;)
bne.b .L_rep
bra.w _common_exit
; suba.l d5,sp
; movem.l (sp)+,d0-d5/a0-a4
; rts
; nrv2r decompression in 68000 assembly
; by ross
;
; On entry:
; a0 src pointer
; [a1 dest pointer]
; (decompress also to a1=a0)
;
; On exit:
; all preserved but
; a1 = dest start
;
; Register usage:
; a2 m_pos
; a3 constant: $cff
; a4 2nd src pointer (in stack)
;
; d0 bit buffer
; d1 m_off
; d2 m_len or -1
;
; d3 last_m_off
; d4 constant: 2
; d5 reserved space on stack
;
;
; Notes:
; we have max_offset = 2^23, so we can use some word arithmetics on d1
; we have max_match = 65535, so we can use word arithmetics on d2
;
nrv2r_unpack
; movem.l d0-d5/a0/a2-a4,-(sp)
; lea (a0),a1 ; if (a1) lea (a0),a4
adda.l (a0),a0 ; end of packed data
move.l -(a0),(a1) ; if (a1) move.l -(a0),(a4)
adda.l -(a0),a1 ; end of buffer
move.b -(a0),d1 ; ~stack usage
; moveq #-2,d5
and.b d1,d5
adda.l d5,sp ; reserve space
lea (sp),a4
._stk move.b -(a0),(a4)+
addq.b #1,d1
bne.b ._stk
; ------------- setup constants -----------
; moveq #-$80,d0 ; d0.b = $80 (byte refill flag)
; moveq #-1,d2
; moveq #0,d3 ; last_off = 0(1)
; moveq #2,d4
movea.w #$cff,a3
; ------------- DECOMPRESSION -------------
.decompr_literal
move.b -(a0),-(a1)
.decompr_loop
add.b d0,d0
bcc.b .decompr_match
bne.b .decompr_literal
move.b -(a0),d0
addx.b d0,d0
bcs.b .decompr_literal
.decompr_match
moveq #1,d1
.decompr_gamma_1
add.b d0,d0
bne.b ._g_1
move.b -(a0),d0
addx.b d0,d0
._g_1 addx.w d1,d1 ; max 2^23!
add.b d0,d0
bcc.b .decompr_gamma_1
bne.b .decompr_select
move.b -(a0),d0
addx.b d0,d0
bcc.b .decompr_gamma_1
.decompr_select
subq.w #3,d1
bcs.b .decompr_get_mlen ; last m_off
bmi.b .decompr_exit_token
lsl.l #8,d1
move.b -(a0),d1
move.l d1,d3 ; last_m_off = m_off
.decompr_get_mlen ; implicit d2 = -1
add.b d0,d0
bne.b ._e_1
move.b -(a0),d0
addx.b d0,d0
._e_1 addx.w d2,d2
add.b d0,d0
bne.b ._e_2
move.b -(a0),d0
addx.b d0,d0
._e_2 addx.w d2,d2
lea 1(a1,d3.l),a2
addq.w #2,d2
bgt.b .decompr_gamma_2
.decompr_tiny_mlen
move.l a3,d1
sub.l d3,d1
addx.w d4,d2
.L_copy2 move.b -(a2),-(a1)
.L_copy1 move.b -(a2),-(a1)
dbra d2,.L_copy1
.L_rep bra.b .decompr_loop
.decompr_gamma_2 ; implicit d2 = 1
add.b d0,d0
bne.b ._g_2
move.b -(a0),d0
addx.b d0,d0
._g_2 addx.w d2,d2
add.b d0,d0
bcc.b .decompr_gamma_2
bne.b .decompr_large_mlen
move.b -(a0),d0
addx.b d0,d0
bcc.b .decompr_gamma_2
.decompr_large_mlen
move.b -(a2),-(a1)
move.b -(a2),-(a1)
cmpa.l d3,a3
bcs.b .L_copy2
move.b -(a2),-(a1)
dbra d2,.L_copy1
.decompr_exit_token
lea (a4),a0
bclr d2,d2 ; ;)
bne.b .L_rep
_common_exit
suba.l d5,sp
movem.l (sp)+,d0-d5/a0-a4
rts
Compressor from a previous link in github (only the exe).
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