grub/grub-core/kern/i386/pc/lzma_decode.S
Vladimir 'phcoder' Serbinenko 3197c86ba8 Remove dead code in decompressor
2010-09-21 10:07:12 +02:00

614 lines
9.4 KiB
ArmAsm

/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2008 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#define FIXED_PROPS
#define LZMA_BASE_SIZE 1846
#define LZMA_LIT_SIZE 768
#define LZMA_PROPERTIES_SIZE 5
#define kNumTopBits 24
#define kTopValue (1 << kNumTopBits)
#define kNumBitModelTotalBits 11
#define kBitModelTotal (1 << kNumBitModelTotalBits)
#define kNumMoveBits 5
#define kNumPosBitsMax 4
#define kNumPosStatesMax (1 << kNumPosBitsMax)
#define kLenNumLowBits 3
#define kLenNumLowSymbols (1 << kLenNumLowBits)
#define kLenNumMidBits 3
#define kLenNumMidSymbols (1 << kLenNumMidBits)
#define kLenNumHighBits 8
#define kLenNumHighSymbols (1 << kLenNumHighBits)
#define LenChoice 0
#define LenChoice2 (LenChoice + 1)
#define LenLow (LenChoice2 + 1)
#define LenMid (LenLow + (kNumPosStatesMax << kLenNumLowBits))
#define LenHigh (LenMid + (kNumPosStatesMax << kLenNumMidBits))
#define kNumLenProbs (LenHigh + kLenNumHighSymbols)
#define kNumStates 12
#define kNumLitStates 7
#define kStartPosModelIndex 4
#define kEndPosModelIndex 14
#define kNumFullDistances (1 << (kEndPosModelIndex >> 1))
#define kNumPosSlotBits 6
#define kNumLenToPosStates 4
#define kNumAlignBits 4
#define kAlignTableSize (1 << kNumAlignBits)
#define kMatchMinLen 2
#define IsMatch 0
#define IsRep (IsMatch + (kNumStates << kNumPosBitsMax))
#define IsRepG0 (IsRep + kNumStates)
#define IsRepG1 (IsRepG0 + kNumStates)
#define IsRepG2 (IsRepG1 + kNumStates)
#define IsRep0Long (IsRepG2 + kNumStates)
#define PosSlot (IsRep0Long + (kNumStates << kNumPosBitsMax))
#define SpecPos (PosSlot + (kNumLenToPosStates << kNumPosSlotBits))
#define Align (SpecPos + kNumFullDistances - kEndPosModelIndex)
#define LenCoder (Align + kAlignTableSize)
#define RepLenCoder (LenCoder + kNumLenProbs)
#define Literal (RepLenCoder + kNumLenProbs)
#define out_size 8(%ebp)
#define now_pos -4(%ebp)
#define prev_byte -8(%ebp)
#define range -12(%ebp)
#define code -16(%ebp)
#define state -20(%ebp)
#define rep0 -24(%ebp)
#define rep1 -28(%ebp)
#define rep2 -32(%ebp)
#define rep3 -36(%ebp)
#ifdef FIXED_PROPS
#define FIXED_LC 3
#define FIXED_LP 0
#define FIXED_PB 2
#define POS_STATE_MASK ((1 << (FIXED_PB)) - 1)
#define LIT_POS_MASK ((1 << (FIXED_LP)) - 1)
#define LOCAL_SIZE 36
#else
#define lc (%ebx)
#define lp 4(%ebx)
#define pb 8(%ebx)
#define probs 12(%ebx)
#define pos_state_mask -40(%ebp)
#define lit_pos_mask -44(%ebp)
#define LOCAL_SIZE 44
#endif
RangeDecoderBitDecode:
#ifdef FIXED_PROPS
leal (%ebx, %eax, 4), %eax
#else
shll $2, %eax
addl probs, %eax
#endif
movl %eax, %ecx
movl (%ecx), %eax
movl range, %edx
shrl $kNumBitModelTotalBits, %edx
mull %edx
cmpl code, %eax
jbe 1f
movl %eax, range
movl $kBitModelTotal, %edx
subl (%ecx), %edx
shrl $kNumMoveBits, %edx
addl %edx, (%ecx)
clc
3:
pushf
cmpl $kTopValue, range
jnc 2f
shll $8, code
lodsb
movb %al, code
shll $8, range
2:
popf
ret
1:
subl %eax, range
subl %eax, code
movl (%ecx), %edx
shrl $kNumMoveBits, %edx
subl %edx, (%ecx)
stc
jmp 3b
RangeDecoderBitTreeDecode:
RangeDecoderReverseBitTreeDecode:
movzbl %cl, %ecx
xorl %edx, %edx
pushl %edx
incl %edx
pushl %edx
1:
pushl %eax
pushl %ecx
pushl %edx
addl %edx, %eax
call RangeDecoderBitDecode
popl %edx
popl %ecx
jnc 2f
movl 4(%esp), %eax
orl %eax, 8(%esp)
stc
2:
adcl %edx, %edx
popl %eax
shll $1, (%esp)
loop 1b
popl %ecx
subl %ecx, %edx /* RangeDecoderBitTreeDecode */
popl %ecx /* RangeDecoderReverseBitTreeDecode */
ret
LzmaLenDecode:
pushl %eax
addl $LenChoice, %eax
call RangeDecoderBitDecode
popl %eax
jc 1f
pushl $0
movb $kLenNumLowBits, %cl
addl $LenLow, %eax
2:
movl 12(%esp), %edx
shll %cl, %edx
addl %edx, %eax
3:
call RangeDecoderBitTreeDecode
popl %eax
addl %eax, %edx
ret
1:
pushl %eax
addl $LenChoice2, %eax
call RangeDecoderBitDecode
popl %eax
jc 1f
pushl $kLenNumLowSymbols
movb $kLenNumMidBits, %cl
addl $LenMid, %eax
jmp 2b
1:
pushl $(kLenNumLowSymbols + kLenNumMidSymbols)
addl $LenHigh, %eax
movb $kLenNumHighBits, %cl
jmp 3b
WriteByte:
movb %al, prev_byte
stosb
incl now_pos
ret
/*
* int LzmaDecode(CLzmaDecoderState *vs,
* const unsigned char *inStream,
* unsigned char *outStream,
* SizeT outSize);
*/
_LzmaDecodeA:
pushl %ebp
movl %esp, %ebp
subl $LOCAL_SIZE, %esp
#ifndef ASM_FILE
pushl %esi
pushl %edi
pushl %ebx
movl %eax, %ebx
movl %edx, %esi
pushl %ecx
#else
pushl %edi
#endif
cld
#ifdef FIXED_PROPS
movl %ebx, %edi
movl $(Literal + (LZMA_LIT_SIZE << (FIXED_LC + FIXED_LP))), %ecx
#else
movl $LZMA_LIT_SIZE, %eax
movb lc, %cl
addb lp, %cl
shll %cl, %eax
addl $Literal, %eax
movl %eax, %ecx
movl probs, %edi
#endif
movl $(kBitModelTotal >> 1), %eax
rep
stosl
popl %edi
xorl %eax, %eax
movl %eax, now_pos
movl %eax, prev_byte
movl %eax, state
incl %eax
movl %eax, rep0
movl %eax, rep1
movl %eax, rep2
movl %eax, rep3
#ifndef FIXED_PROPS
movl %eax, %edx
movb pb, %cl
shll %cl, %edx
decl %edx
movl %edx, pos_state_mask
movl %eax, %edx
movb lp, %cl
shll %cl, %edx
decl %edx
movl %edx, lit_pos_mask;
#endif
/* RangeDecoderInit */
negl %eax
movl %eax, range
incl %eax
movb $5, %cl
1:
shll $8, %eax
lodsb
loop 1b
movl %eax, code
lzma_decode_loop:
movl now_pos, %eax
cmpl out_size, %eax
jb 1f
#ifndef ASM_FILE
xorl %eax, %eax
popl %ebx
popl %edi
popl %esi
#endif
movl %ebp, %esp
popl %ebp
ret
1:
#ifdef FIXED_PROPS
andl $POS_STATE_MASK, %eax
#else
andl pos_state_mask, %eax
#endif
pushl %eax /* posState */
movl state, %edx
shll $kNumPosBitsMax, %edx
addl %edx, %eax
pushl %eax /* (state << kNumPosBitsMax) + posState */
call RangeDecoderBitDecode
jc 1f
movl now_pos, %eax
#ifdef FIXED_PROPS
andl $LIT_POS_MASK, %eax
shll $FIXED_LC, %eax
movl prev_byte, %edx
shrl $(8 - FIXED_LC), %edx
#else
andl lit_pos_mask, %eax
movb lc, %cl
shll %cl, %eax
negb %cl
addb $8, %cl
movl prev_byte, %edx
shrl %cl, %edx
#endif
addl %edx, %eax
movl $LZMA_LIT_SIZE, %edx
mull %edx
addl $Literal, %eax
pushl %eax
incl %edx /* edx = 1 */
movl rep0, %eax
negl %eax
pushl (%edi, %eax) /* matchByte */
cmpb $kNumLitStates, state
jb 5f
/* LzmaLiteralDecodeMatch */
3:
cmpl $0x100, %edx
jae 4f
xorl %eax, %eax
shlb $1, (%esp)
adcl %eax, %eax
pushl %eax
pushl %edx
shll $8, %eax
leal 0x100(%edx, %eax), %eax
addl 12(%esp), %eax
call RangeDecoderBitDecode
setc %al
popl %edx
adcl %edx, %edx
popl %ecx
cmpb %cl, %al
jz 3b
5:
/* LzmaLiteralDecode */
cmpl $0x100, %edx
jae 4f
pushl %edx
movl %edx, %eax
addl 8(%esp), %eax
call RangeDecoderBitDecode
popl %edx
adcl %edx, %edx
jmp 5b
4:
addl $16, %esp
movb %dl, %al
call WriteByte
movb state, %al
cmpb $4, %al
jae 2f
xorb %al, %al
jmp 3f
2:
subb $3, %al
cmpb $7, %al
jb 3f
subb $3, %al
3:
movb %al, state
jmp lzma_decode_loop
1:
movl state, %eax
addl $IsRep, %eax
call RangeDecoderBitDecode
jnc 1f
movl state, %eax
addl $IsRepG0, %eax
call RangeDecoderBitDecode
jc 10f
movl (%esp), %eax
addl $IsRep0Long, %eax
call RangeDecoderBitDecode
jc 20f
cmpb $7, state
movb $9, state
jb 100f
addb $2, state
100:
movl $1, %ecx
3:
movl rep0, %edx
negl %edx
4:
movb (%edi, %edx), %al
call WriteByte
loop 4b
popl %eax
popl %eax
jmp lzma_decode_loop
10:
movl state, %eax
addl $IsRepG1, %eax
call RangeDecoderBitDecode
movl rep1, %edx
jnc 100f
movl state, %eax
addl $IsRepG2, %eax
call RangeDecoderBitDecode
movl rep2, %edx
jnc 1000f
movl rep2, %edx
xchgl rep3, %edx
1000:
pushl rep1
popl rep2
100:
xchg rep0, %edx
movl %edx, rep1
20:
movl $RepLenCoder, %eax
call LzmaLenDecode
cmpb $7, state
movb $8, state
jb 100f
addb $3, state
100:
jmp 2f
1:
movl rep0, %eax
xchgl rep1, %eax
xchgl rep2, %eax
movl %eax, rep3
cmpb $7, state
movb $7, state
jb 10f
addb $3, state
10:
movl $LenCoder, %eax
call LzmaLenDecode
pushl %edx
movl $(kNumLenToPosStates - 1), %eax
cmpl %eax, %edx
jbe 100f
movl %eax, %edx
100:
movb $kNumPosSlotBits, %cl
shll %cl, %edx
leal PosSlot(%edx), %eax
call RangeDecoderBitTreeDecode
movl %edx, rep0
cmpl $kStartPosModelIndex, %edx
jb 100f
movl %edx, %ecx
shrl $1, %ecx
decl %ecx
movzbl %dl, %eax
andb $1, %al
orb $2, %al
shll %cl, %eax
movl %eax, rep0
cmpl $kEndPosModelIndex, %edx
jae 200f
movl rep0, %eax
addl $(SpecPos - 1), %eax
subl %edx, %eax
jmp 300f
200:
subb $kNumAlignBits, %cl
/* RangeDecoderDecodeDirectBits */
xorl %edx, %edx
1000:
shrl $1, range
shll $1, %edx
movl range, %eax
cmpl %eax, code
jb 2000f
subl %eax, code
orb $1, %dl
2000:
cmpl $kTopValue, %eax
jae 3000f
shll $8, range
shll $8, code
lodsb
movb %al, code
3000:
loop 1000b
movb $kNumAlignBits, %cl
shll %cl, %edx
addl %edx, rep0
movl $Align, %eax
300:
call RangeDecoderReverseBitTreeDecode
addl %ecx, rep0
100:
incl rep0
popl %edx
2:
addl $kMatchMinLen, %edx
movl %edx, %ecx
jmp 3b