diff --git a/asm/6809/unlzsa1b-6309.s b/asm/6809/unlzsa1b-6309.s new file mode 100644 index 0000000..c975f19 --- /dev/null +++ b/asm/6809/unlzsa1b-6309.s @@ -0,0 +1,96 @@ +; unlzsa1-6309.s - H6309 backward decompressor for raw LZSA1 - 105 bytes +; compress with lzsa -f1 -r -b +; +; in: x = last byte of compressed data +; y = last byte of decompression buffer +; out: y = first byte of decompressed data +; +; Copyright (C) 2020 Emmanuel Marty, Doug Masten +; +; This software is provided 'as-is', without any express or implied +; warranty. In no event will the authors be held liable for any damages +; arising from the use of this software. +; +; Permission is granted to anyone to use this software for any purpose, +; including commercial applications, and to alter it and redistribute it +; freely, subject to the following restrictions: +; +; 1. The origin of this software must not be misrepresented; you must not +; claim that you wrote the original software. If you use this software +; in a product, an acknowledgment in the product documentation would be +; appreciated but is not required. +; 2. Altered source versions must be plainly marked as such, and must not be +; misrepresented as being the original software. +; 3. This notice may not be removed or altered from any source distribution. + +decompress_lzsa1 + leax 1,x + bra lz1start + +lz1bigof ldd ,--x ; O set: load long 16-bit (negative, signed) offest +lz1gotof negd ; reverse sign of offset in D + decd ; tfm below is post-decrement, not pre-decrement + leau d,y ; put backreference start address in U (dst+offset) + + ldd #$000f ; clear MSB match length and set mask for MMMM + andb ,s+ ; isolate MMMM (embedded match length) in token + addb #$03 ; add MIN_MATCH_SIZE + cmpb #$12 ; MATCH_RUN_LEN? + bne lz1gotln ; no, we have the full match length, go copy + + addb ,-x ; add extra match length byte + MIN_MATCH_SIZE + MATCH_RUN_LEN + bcc lz1gotln ; if no overflow, we have the full length + bne lz1midln + + ldd ,--x ; load 16-bit len in D (low part in B, high in A) + bne lz1gotln ; check if we hit EOD (16-bit length = 0) + + rts ; done, bail + +lz1midln tfr b,a ; copy high part of len into A + ldb ,-x ; grab low 8 bits of len in B + +lz1gotln tfr d,w ; set W with match length for TFM instruction + leay -1,y ; tfm is post-decrement + tfm u-,y- ; copy match bytes +lz1start leay 1,y ; fix destination for pre-decrement again + +lz1token ldb ,-x ; load next token into B: O|LLL|MMMM + pshs b ; save it + + andb #$70 ; isolate LLL (embedded literals count) in B + beq lz1nolt ; skip if no literals + cmpb #$70 ; LITERALS_RUN_LEN? + bne lz1declt ; if not, we have the complete count, go unshift + + ldb ,-x ; load extra literals count byte + addb #$07 ; add LITERALS_RUN_LEN + bcc lz1gotla ; if no overflow, we got the complete count, copy + bne lz1midlt + + ldd ,--x ; load 16 bit count in D (low part in B, high in A) + bra lz1gotlt ; we now have the complete count, go copy + +lz1midlt tfr b,a ; copy high part of literals count into A + ldb ,-x ; load low 8 bits of literals count + bra lz1gotlt ; we now have the complete count, go copy + +lz1declt lsrb ; shift literals count into place + lsrb + lsrb + lsrb + +lz1gotla clra ; clear A (high part of literals count) +lz1gotlt tfr d,w ; set W with literals count for TFM instruction + leax -1,x ; tfm is post-decrement + leay -1,y + tfm x-,y- ; copy literal bytes + leax 1,x + leay 1,y + +lz1nolt ldb ,s ; get token again, don't pop it from the stack + bmi lz1bigof ; test O bit (small or large offset) + + ldb ,-x ; load either 8-bit or LSB 16-bit offset (negative, signed) + lda #$ff ; set high 8 bits + bra lz1gotof diff --git a/asm/6809/unlzsa2b-6309.s b/asm/6809/unlzsa2b-6309.s new file mode 100644 index 0000000..e3b2c0e --- /dev/null +++ b/asm/6809/unlzsa2b-6309.s @@ -0,0 +1,136 @@ +; unlzsa2b-6309.s - H6309 backward decompressor for raw LZSA2 - 163 bytes +; compress with lzsa -f2 -r -b +; +; in: x = last byte of compressed data +; y = last byte of decompression buffer +; out: y = first byte of decompressed data +; +; Copyright (C) 2020 Emmanuel Marty, Doug Masten +; +; This software is provided 'as-is', without any express or implied +; warranty. In no event will the authors be held liable for any damages +; arising from the use of this software. +; +; Permission is granted to anyone to use this software for any purpose, +; including commercial applications, and to alter it and redistribute it +; freely, subject to the following restrictions: +; +; 1. The origin of this software must not be misrepresented; you must not +; claim that you wrote the original software. If you use this software +; in a product, an acknowledgment in the product documentation would be +; appreciated but is not required. +; 2. Altered source versions must be plainly marked as such, and must not be +; misrepresented as being the original software. +; 3. This notice may not be removed or altered from any source distribution. + +decompress_lzsa2 + clr lz2nibct ; reset nibble available flag + leax 1,x + leay 1,y + bra lz2token + +lz2nibct fcb 0 ; nibble ready flag + +lz2replg lslb ; push token's Y flag bit into carry + bcs lz2rep16 ; if token's Y bit is set, rep or 16 bit offset + + sex ; push token's Z flag bit into reg A + lbsr lz2nibl ; get offset nibble in B + lsla ; push token's Z flag bit into carry + rolb ; shift Z flag from carry into bit 0 of B + eorb #$e1 ; set bits 13-15 of offset, reverse bit 8 + tfr b,a ; copy bits 8-15 of offset into A + suba #$02 ; substract 512 from offset + bra lz2lowof + +lz2rep16 bmi lz2repof ; if token's Z flag bit is set, rep match + lda ,-x ; load high 8 bits of (negative, signed) offset +lz2lowof ldb ,-x ; load low 8 bits of offset + +lz2gotof negd ; reverse sign of offset in D + decd ; tfm below is post-decrement, not pre-decrement + std lz2moff+2 ; store match offset + +lz2repof ldd #$0007 ; clear MSB match length and set mask for MMM + andb ,u ; isolate MMM (embedded match length) in token +lz2moff leau $aaaa,y ; put backreference start address in U (dst+offset) + addb #$02 ; add MIN_MATCH_SIZE_V2 + cmpb #$09 ; MIN_MATCH_SIZE_V2 + MATCH_RUN_LEN_V2? + bne lz2gotln ; no, we have the full match length, go copy + + bsr lz2nibl ; get offset nibble in B + addb #$09 ; add MIN_MATCH_SIZE_V2 + MATCH_RUN_LEN_V2 + cmpb #$18 ; MIN_MATCH_SIZE_V2 + MATCH_RUN_LEN_V2 + 15? + bne lz2gotln ; if not, we have the full match length, go copy + + addb ,-x ; add extra length byte + MIN_MATCH_SIZE_V2 + MATCH_RUN_LEN_V2 + 15 + bcc lz2gotln ; if no overflow, we have the full length + beq lz2done ; detect EOD code + + ldd ,--x ; load 16-bit len in D (low part in B, high in A) + +lz2gotln tfr d,w ; set W with match count for TFM instruction + leay -1,y ; tfm is post-decrement + tfm u-,y- ; copy match bytes + leay 1,y ; fix destination for pre-decrement again + +lz2token ldb ,-x ; load next token into B: XYZ|LL|MMM + tfr x,u ; save token address + andb #$18 ; isolate LL (embedded literals count) in B + beq lz2nolt ; skip if no literals + cmpb #$18 ; LITERALS_RUN_LEN_V2? + bne lz2declt ; if not, we have the complete count, go unshift + + bsr lz2nibl ; get extra literals length nibble in B + addb #$03 ; add LITERALS_RUN_LEN_V2 + cmpb #$12 ; LITERALS_RUN_LEN_V2 + 15 ? + bne lz2gotla ; if not, we have the full literals count, go copy + + addb ,-x ; add extra literals count byte + LITERALS_RUN_LEN + 15 + bcc lz2gotla ; if no overflow, we got the complete count, copy + + ldd ,--x ; load 16 bit count in D (low part in B, high in A) + bra lz2gotlt ; we now have the complete count, go copy + +lz2declt lsrb ; shift literals count into place + lsrb + lsrb +lz2gotla clra ; clear A (high part of literals count) + +lz2gotlt tfr d,w ; set W with literals count for TFM instruction + leax -1,x ; tfm is post-decrement + leay -1,y + tfm x-,y- ; copy literal bytes + leax 1,x + leay 1,y + +lz2nolt ldb ,u ; get token again + lslb ; push token's X flag bit into carry + bcs lz2replg ; if token's X bit is set, rep or large offset + + lslb ; push token's Y flag bit into carry + sex ; push token's Z flag bit into reg A (carry flag is not effected) + bcs lz2offs9 ; if token's Y bit is set, 9 bits offset + + bsr lz2nibl ; get offset nibble in B + lsla ; retrieve token's Z flag bit and push into carry + rolb ; shift Z flag from carry into bit 0 of B + eorb #$e1 ; set bits 5-7 of offset, reverse bit 0 + sex ; set bits 8-15 of offset to $FF + bra lz2gotof + +lz2offs9 deca ; set bits 9-15 of offset, reverse bit 8 + bra lz2lowof + +lz2nibl ldb #$aa + com lz2nibct ; nibble ready? + bpl lz2gotnb + + ldb ,-x ; load two nibbles + stb lz2nibl+1 ; store nibble for next time (low 4 bits) + lsrb ; shift 4 high bits of nibble down + lsrb + lsrb + lsrb +lz2gotnb andb #$0f ; only keep low 4 bits +lz2done rts