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Debugging decompression.

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This commit is contained in:
Martin Haye 2014-03-13 10:22:49 -07:00
parent 37f4863e30
commit 95fbd98acb
1 changed files with 12 additions and 11 deletions
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23
Platform/Apple/virtual/src/core/mem.s
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@ -1061,7 +1061,6 @@ disk_finishLoad: !zone
!byte MLI_SET_MARK
!word .setMarkParams
bcs .prodosErr
jsr readToBuf ; read first pages into buffer
jsr lz4Decompress ; decompress (or copy if uncompressed)
.resume ldy .ysave
.next lda (pTmp),y ; lo byte of length
@ -1150,9 +1149,11 @@ readToMain: !zone
readToBuf: !zone
; Read as much data as we can, up to min(compLen, bufferSize) into the diskBuf.
lda #0
sta readAddr
sta readAddr ; buffer addr always on even page boundary
sta pSrc
lda #>diskBuf ; we're reading into a buffer in main mem
sta readAddr+1
sta pSrc+1 ; restart src pointer at start of buffer
.nextGroup:
ldx reqLen
lda reqLen+1 ; see how many pages we want
@ -1170,6 +1171,7 @@ readToBuf: !zone
lda reqLen+1 ; all 16 bits of reqLen
sbc readLen+1
sta reqLen+1
ldy #0 ; index for reading first byte
rts ; all done
;------------------------------------------------------------------------------
@ -1189,6 +1191,7 @@ lz4Decompress: !zone
}
!if DEBUG { jsr .debug1 }
jsr readToBuf ; read first pages into buffer
ldx #<clrAuxWr ; start by assuming write to main mem
ldy #<clrAuxRd ; and read from main mem
lda isAuxCmd ; if we're decompressing to aux...
@ -1252,6 +1255,7 @@ lz4Decompress: !zone
bne .litCopy ; if non-zero, loop again
dec ucLen+1 ; low-byte of count is zero. Decrement hi-byte
bpl .litCopy ; If non-negative, loop again. NOTE: This would fail if we had blocks >= 32K
inc ucLen+1 ; to ensure it's zero for the next len decode
sta clrAuxWr ; back to writing main mem
.endChk1:
cpx #11 ; end check - self-modified earlier
@ -1294,11 +1298,12 @@ lz4Decompress: !zone
bne + ; if not, no need to extend length
jsr .longLen ; need to extend the length
+ sty tmp ; save index to source pointer, so we can use Y...
!if DEBUG { sta ucLen+1 : jsr .debug3 }
!if DEBUG { sta ucLen : jsr .debug3 }
tay ; ...to count bytes
.auxWr2 sta setAuxWr ; self-modified earlier, based on isAuxCmd
jsr .matchCopy ; copy match bytes (aux->aux, or main->main)
sta clrAuxWr ; back to reading main mem
inc ucLen+1 ; to make it zero for the next match decode
+ ldy tmp ; restore index to source pointer
jmp .getToken ; go on to the next token in the compressed stream
; Subroutine to copy bytes, either main->main or aux->aux. We put it down in the
@ -1332,15 +1337,14 @@ lz4Decompress: !zone
.longLen:
sta ucLen ; save what we got so far
- +LOAD_YSRC ; get another byte
pha ; save it for end-check later
cmp #$FF ; check for special there-is-more marker byte
php ; save result of that
clc
adc ucLen ; add $FF to ucLen
sta ucLen
bcc + ; no carry, only lo byte has changed
inc ucLen+1 ; increment hi byte of ucLen
pla ; get back the byte loaded
cmp #$FF ; special value $FF?
bne - ; no, go back for more
+ plp ; retrieve comparison status from earlier
beq - ; if it was $FF, go back for more len bytes
rts
nextSrcPage:
@ -1351,9 +1355,6 @@ nextSrcPage:
bne + ; if not, we're done
sta clrAuxWr ; buffer is in main mem
jsr readToBuf ; read more pages
lda #<diskBuf ; begin again at start of buffer
sta pSrc+1
ldy #0 ; first byte
.auxWr3 sta setAuxWr ; go back to writing aux mem (self-modified for aux or main)
pla ; restore loaded byte
+ rts