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linux/lib/decompress_unlzma.c
Alain Knaff bc22c17e12 bzip2/lzma: library support for gzip, bzip2 and lzma decompression 
Impact: Replaces inflate.c with a wrapper around zlib_inflate; new library code

This is the first part of the bzip2/lzma patch

The bzip patch is based on an idea by Christian Ludwig, includes support for
compressing the kernel with bzip2 or lzma rather than gzip. Both
compressors give smaller sizes than gzip.  Lzma's decompresses faster
than bzip2.

It also supports ramdisks and initramfs' compressed using these two
compressors.

The functionality has been successfully used for a couple of years by
the udpcast project

This version applies to "tip" kernel 2.6.28

This part contains:
- changed inflate.c to accomodate rest of patch
- implementation of bzip2 compression (not used at this stage yet)
- implementation of lzma compression (not used at this stage yet)
- Makefile routines to support bzip2 and lzma kernel compression

Signed-off-by: Alain Knaff <alain@knaff.lu>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-04 15:53:34 -08:00

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/* Lzma decompressor for Linux kernel. Shamelessly snarfed
*from busybox 1.1.1
*
*Linux kernel adaptation
*Copyright (C) 2006 Alain < alain@knaff.lu >
*
*Based on small lzma deflate implementation/Small range coder
*implementation for lzma.
*Copyright (C) 2006 Aurelien Jacobs < aurel@gnuage.org >
*
*Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
*Copyright (C) 1999-2005 Igor Pavlov
*
*Copyrights of the parts, see headers below.
*
*
*This program is free software; you can redistribute it and/or
*modify it under the terms of the GNU Lesser General Public
*License as published by the Free Software Foundation; either
*version 2.1 of the License, or (at your option) any later version.
*
*This program 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
*Lesser General Public License for more details.
*
*You should have received a copy of the GNU Lesser General Public
*License along with this library; if not, write to the Free Software
*Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef STATIC
#include <linux/decompress/unlzma.h>
#endif /* STATIC */
#include <linux/decompress/mm.h>
#define MIN(a, b) (((a) < (b)) ? (a) : (b))
static long long INIT read_int(unsigned char *ptr, int size)
{
int i;
long long ret = 0;
for (i = 0; i < size; i++)
ret = (ret << 8) | ptr[size-i-1];
return ret;
}
#define ENDIAN_CONVERT(x) \
x = (typeof(x))read_int((unsigned char *)&x, sizeof(x))
/* Small range coder implementation for lzma.
*Copyright (C) 2006 Aurelien Jacobs < aurel@gnuage.org >
*
*Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
*Copyright (c) 1999-2005 Igor Pavlov
*/
#include <linux/compiler.h>
#define LZMA_IOBUF_SIZE 0x10000
struct rc {
int (*fill)(void*, unsigned int);
uint8_t *ptr;
uint8_t *buffer;
uint8_t *buffer_end;
int buffer_size;
uint32_t code;
uint32_t range;
uint32_t bound;
};
#define RC_TOP_BITS 24
#define RC_MOVE_BITS 5
#define RC_MODEL_TOTAL_BITS 11
/* Called twice: once at startup and once in rc_normalize() */
static void INIT rc_read(struct rc *rc)
{
rc->buffer_size = rc->fill((char *)rc->buffer, LZMA_IOBUF_SIZE);
if (rc->buffer_size <= 0)
error("unexpected EOF");
rc->ptr = rc->buffer;
rc->buffer_end = rc->buffer + rc->buffer_size;
}
/* Called once */
static inline void INIT rc_init(struct rc *rc,
int (*fill)(void*, unsigned int),
char *buffer, int buffer_size)
{
rc->fill = fill;
rc->buffer = (uint8_t *)buffer;
rc->buffer_size = buffer_size;
rc->buffer_end = rc->buffer + rc->buffer_size;
rc->ptr = rc->buffer;
rc->code = 0;
rc->range = 0xFFFFFFFF;
}
static inline void INIT rc_init_code(struct rc *rc)
{
int i;
for (i = 0; i < 5; i++) {
if (rc->ptr >= rc->buffer_end)
rc_read(rc);
rc->code = (rc->code << 8) | *rc->ptr++;
}
}
/* Called once. TODO: bb_maybe_free() */
static inline void INIT rc_free(struct rc *rc)
{
free(rc->buffer);
}
/* Called twice, but one callsite is in inline'd rc_is_bit_0_helper() */
static void INIT rc_do_normalize(struct rc *rc)
{
if (rc->ptr >= rc->buffer_end)
rc_read(rc);
rc->range <<= 8;
rc->code = (rc->code << 8) | *rc->ptr++;
}
static inline void INIT rc_normalize(struct rc *rc)
{
if (rc->range < (1 << RC_TOP_BITS))
rc_do_normalize(rc);
}
/* Called 9 times */
/* Why rc_is_bit_0_helper exists?
*Because we want to always expose (rc->code < rc->bound) to optimizer
*/
static inline uint32_t INIT rc_is_bit_0_helper(struct rc *rc, uint16_t *p)
{
rc_normalize(rc);
rc->bound = *p * (rc->range >> RC_MODEL_TOTAL_BITS);
return rc->bound;
}
static inline int INIT rc_is_bit_0(struct rc *rc, uint16_t *p)
{
uint32_t t = rc_is_bit_0_helper(rc, p);
return rc->code < t;
}
/* Called ~10 times, but very small, thus inlined */
static inline void INIT rc_update_bit_0(struct rc *rc, uint16_t *p)
{
rc->range = rc->bound;
*p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS;
}
static inline void rc_update_bit_1(struct rc *rc, uint16_t *p)
{
rc->range -= rc->bound;
rc->code -= rc->bound;
*p -= *p >> RC_MOVE_BITS;
}
/* Called 4 times in unlzma loop */
static int INIT rc_get_bit(struct rc *rc, uint16_t *p, int *symbol)
{
if (rc_is_bit_0(rc, p)) {
rc_update_bit_0(rc, p);
*symbol *= 2;
return 0;
} else {
rc_update_bit_1(rc, p);
*symbol = *symbol * 2 + 1;
return 1;
}
}
/* Called once */
static inline int INIT rc_direct_bit(struct rc *rc)
{
rc_normalize(rc);
rc->range >>= 1;
if (rc->code >= rc->range) {
rc->code -= rc->range;
return 1;
}
return 0;
}
/* Called twice */
static inline void INIT
rc_bit_tree_decode(struct rc *rc, uint16_t *p, int num_levels, int *symbol)
{
int i = num_levels;
*symbol = 1;
while (i--)
rc_get_bit(rc, p + *symbol, symbol);
*symbol -= 1 << num_levels;
}
/*
* Small lzma deflate implementation.
* Copyright (C) 2006 Aurelien Jacobs < aurel@gnuage.org >
*
* Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
* Copyright (C) 1999-2005 Igor Pavlov
*/
struct lzma_header {
uint8_t pos;
uint32_t dict_size;
uint64_t dst_size;
} __attribute__ ((packed)) ;
#define LZMA_BASE_SIZE 1846
#define LZMA_LIT_SIZE 768
#define LZMA_NUM_POS_BITS_MAX 4
#define LZMA_LEN_NUM_LOW_BITS 3
#define LZMA_LEN_NUM_MID_BITS 3
#define LZMA_LEN_NUM_HIGH_BITS 8
#define LZMA_LEN_CHOICE 0
#define LZMA_LEN_CHOICE_2 (LZMA_LEN_CHOICE + 1)
#define LZMA_LEN_LOW (LZMA_LEN_CHOICE_2 + 1)
#define LZMA_LEN_MID (LZMA_LEN_LOW \
+ (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS)))
#define LZMA_LEN_HIGH (LZMA_LEN_MID \
+(1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS)))
#define LZMA_NUM_LEN_PROBS (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS))
#define LZMA_NUM_STATES 12
#define LZMA_NUM_LIT_STATES 7
#define LZMA_START_POS_MODEL_INDEX 4
#define LZMA_END_POS_MODEL_INDEX 14
#define LZMA_NUM_FULL_DISTANCES (1 << (LZMA_END_POS_MODEL_INDEX >> 1))
#define LZMA_NUM_POS_SLOT_BITS 6
#define LZMA_NUM_LEN_TO_POS_STATES 4
#define LZMA_NUM_ALIGN_BITS 4
#define LZMA_MATCH_MIN_LEN 2
#define LZMA_IS_MATCH 0
#define LZMA_IS_REP (LZMA_IS_MATCH + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX))
#define LZMA_IS_REP_G0 (LZMA_IS_REP + LZMA_NUM_STATES)
#define LZMA_IS_REP_G1 (LZMA_IS_REP_G0 + LZMA_NUM_STATES)
#define LZMA_IS_REP_G2 (LZMA_IS_REP_G1 + LZMA_NUM_STATES)
#define LZMA_IS_REP_0_LONG (LZMA_IS_REP_G2 + LZMA_NUM_STATES)
#define LZMA_POS_SLOT (LZMA_IS_REP_0_LONG \
+ (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX))
#define LZMA_SPEC_POS (LZMA_POS_SLOT \
+(LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS))
#define LZMA_ALIGN (LZMA_SPEC_POS \
+ LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX)
#define LZMA_LEN_CODER (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS))
#define LZMA_REP_LEN_CODER (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS)
#define LZMA_LITERAL (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS)
struct writer {
uint8_t *buffer;
uint8_t previous_byte;
size_t buffer_pos;
int bufsize;
size_t global_pos;
int(*flush)(void*, unsigned int);
struct lzma_header *header;
};
struct cstate {
int state;
uint32_t rep0, rep1, rep2, rep3;
};
static inline size_t INIT get_pos(struct writer *wr)
{
return
wr->global_pos + wr->buffer_pos;
}
static inline uint8_t INIT peek_old_byte(struct writer *wr,
uint32_t offs)
{
if (!wr->flush) {
int32_t pos;
while (offs > wr->header->dict_size)
offs -= wr->header->dict_size;
pos = wr->buffer_pos - offs;
return wr->buffer[pos];
} else {
uint32_t pos = wr->buffer_pos - offs;
while (pos >= wr->header->dict_size)
pos += wr->header->dict_size;
return wr->buffer[pos];
}
}
static inline void INIT write_byte(struct writer *wr, uint8_t byte)
{
wr->buffer[wr->buffer_pos++] = wr->previous_byte = byte;
if (wr->flush && wr->buffer_pos == wr->header->dict_size) {
wr->buffer_pos = 0;
wr->global_pos += wr->header->dict_size;
wr->flush((char *)wr->buffer, wr->header->dict_size);
}
}
static inline void INIT copy_byte(struct writer *wr, uint32_t offs)
{
write_byte(wr, peek_old_byte(wr, offs));
}
static inline void INIT copy_bytes(struct writer *wr,
uint32_t rep0, int len)
{
do {
copy_byte(wr, rep0);
len--;
} while (len != 0 && wr->buffer_pos < wr->header->dst_size);
}
static inline void INIT process_bit0(struct writer *wr, struct rc *rc,
struct cstate *cst, uint16_t *p,
int pos_state, uint16_t *prob,
int lc, uint32_t literal_pos_mask) {
int mi = 1;
rc_update_bit_0(rc, prob);
prob = (p + LZMA_LITERAL +
(LZMA_LIT_SIZE
* (((get_pos(wr) & literal_pos_mask) << lc)
+ (wr->previous_byte >> (8 - lc))))
);
if (cst->state >= LZMA_NUM_LIT_STATES) {
int match_byte = peek_old_byte(wr, cst->rep0);
do {
int bit;
uint16_t *prob_lit;
match_byte <<= 1;
bit = match_byte & 0x100;
prob_lit = prob + 0x100 + bit + mi;
if (rc_get_bit(rc, prob_lit, &mi)) {
if (!bit)
break;
} else {
if (bit)
break;
}
} while (mi < 0x100);
}
while (mi < 0x100) {
uint16_t *prob_lit = prob + mi;
rc_get_bit(rc, prob_lit, &mi);
}
write_byte(wr, mi);
if (cst->state < 4)
cst->state = 0;
else if (cst->state < 10)
cst->state -= 3;
else
cst->state -= 6;
}
static inline void INIT process_bit1(struct writer *wr, struct rc *rc,
struct cstate *cst, uint16_t *p,
int pos_state, uint16_t *prob) {
int offset;
uint16_t *prob_len;
int num_bits;
int len;
rc_update_bit_1(rc, prob);
prob = p + LZMA_IS_REP + cst->state;
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
cst->rep3 = cst->rep2;
cst->rep2 = cst->rep1;
cst->rep1 = cst->rep0;
cst->state = cst->state < LZMA_NUM_LIT_STATES ? 0 : 3;
prob = p + LZMA_LEN_CODER;
} else {
rc_update_bit_1(rc, prob);
prob = p + LZMA_IS_REP_G0 + cst->state;
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
prob = (p + LZMA_IS_REP_0_LONG
+ (cst->state <<
LZMA_NUM_POS_BITS_MAX) +
pos_state);
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
cst->state = cst->state < LZMA_NUM_LIT_STATES ?
9 : 11;
copy_byte(wr, cst->rep0);
return;
} else {
rc_update_bit_1(rc, prob);
}
} else {
uint32_t distance;
rc_update_bit_1(rc, prob);
prob = p + LZMA_IS_REP_G1 + cst->state;
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
distance = cst->rep1;
} else {
rc_update_bit_1(rc, prob);
prob = p + LZMA_IS_REP_G2 + cst->state;
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
distance = cst->rep2;
} else {
rc_update_bit_1(rc, prob);
distance = cst->rep3;
cst->rep3 = cst->rep2;
}
cst->rep2 = cst->rep1;
}
cst->rep1 = cst->rep0;
cst->rep0 = distance;
}
cst->state = cst->state < LZMA_NUM_LIT_STATES ? 8 : 11;
prob = p + LZMA_REP_LEN_CODER;
}
prob_len = prob + LZMA_LEN_CHOICE;
if (rc_is_bit_0(rc, prob_len)) {
rc_update_bit_0(rc, prob_len);
prob_len = (prob + LZMA_LEN_LOW
+ (pos_state <<
LZMA_LEN_NUM_LOW_BITS));
offset = 0;
num_bits = LZMA_LEN_NUM_LOW_BITS;
} else {
rc_update_bit_1(rc, prob_len);
prob_len = prob + LZMA_LEN_CHOICE_2;
if (rc_is_bit_0(rc, prob_len)) {
rc_update_bit_0(rc, prob_len);
prob_len = (prob + LZMA_LEN_MID
+ (pos_state <<
LZMA_LEN_NUM_MID_BITS));
offset = 1 << LZMA_LEN_NUM_LOW_BITS;
num_bits = LZMA_LEN_NUM_MID_BITS;
} else {
rc_update_bit_1(rc, prob_len);
prob_len = prob + LZMA_LEN_HIGH;
offset = ((1 << LZMA_LEN_NUM_LOW_BITS)
+ (1 << LZMA_LEN_NUM_MID_BITS));
num_bits = LZMA_LEN_NUM_HIGH_BITS;
}
}
rc_bit_tree_decode(rc, prob_len, num_bits, &len);
len += offset;
if (cst->state < 4) {
int pos_slot;
cst->state += LZMA_NUM_LIT_STATES;
prob =
p + LZMA_POS_SLOT +
((len <
LZMA_NUM_LEN_TO_POS_STATES ? len :
LZMA_NUM_LEN_TO_POS_STATES - 1)
<< LZMA_NUM_POS_SLOT_BITS);
rc_bit_tree_decode(rc, prob,
LZMA_NUM_POS_SLOT_BITS,
&pos_slot);
if (pos_slot >= LZMA_START_POS_MODEL_INDEX) {
int i, mi;
num_bits = (pos_slot >> 1) - 1;
cst->rep0 = 2 | (pos_slot & 1);
if (pos_slot < LZMA_END_POS_MODEL_INDEX) {
cst->rep0 <<= num_bits;
prob = p + LZMA_SPEC_POS +
cst->rep0 - pos_slot - 1;
} else {
num_bits -= LZMA_NUM_ALIGN_BITS;
while (num_bits--)
cst->rep0 = (cst->rep0 << 1) |
rc_direct_bit(rc);
prob = p + LZMA_ALIGN;
cst->rep0 <<= LZMA_NUM_ALIGN_BITS;
num_bits = LZMA_NUM_ALIGN_BITS;
}
i = 1;
mi = 1;
while (num_bits--) {
if (rc_get_bit(rc, prob + mi, &mi))
cst->rep0 |= i;
i <<= 1;
}
} else
cst->rep0 = pos_slot;
if (++(cst->rep0) == 0)
return;
}
len += LZMA_MATCH_MIN_LEN;
copy_bytes(wr, cst->rep0, len);
}
STATIC inline int INIT unlzma(unsigned char *buf, int in_len,
int(*fill)(void*, unsigned int),
int(*flush)(void*, unsigned int),
unsigned char *output,
int *posp,
void(*error_fn)(char *x)
)
{
struct lzma_header header;
int lc, pb, lp;
uint32_t pos_state_mask;
uint32_t literal_pos_mask;
uint16_t *p;
int num_probs;
struct rc rc;
int i, mi;
struct writer wr;
struct cstate cst;
unsigned char *inbuf;
int ret = -1;
set_error_fn(error_fn);
if (!flush)
in_len -= 4; /* Uncompressed size hack active in pre-boot
environment */
if (buf)
inbuf = buf;
else
inbuf = malloc(LZMA_IOBUF_SIZE);
if (!inbuf) {
error("Could not allocate input bufer");
goto exit_0;
}
cst.state = 0;
cst.rep0 = cst.rep1 = cst.rep2 = cst.rep3 = 1;
wr.header = &header;
wr.flush = flush;
wr.global_pos = 0;
wr.previous_byte = 0;
wr.buffer_pos = 0;
rc_init(&rc, fill, inbuf, in_len);
for (i = 0; i < sizeof(header); i++) {
if (rc.ptr >= rc.buffer_end)
rc_read(&rc);
((unsigned char *)&header)[i] = *rc.ptr++;
}
if (header.pos >= (9 * 5 * 5))
error("bad header");
mi = 0;
lc = header.pos;
while (lc >= 9) {
mi++;
lc -= 9;
}
pb = 0;
lp = mi;
while (lp >= 5) {
pb++;
lp -= 5;
}
pos_state_mask = (1 << pb) - 1;
literal_pos_mask = (1 << lp) - 1;
ENDIAN_CONVERT(header.dict_size);
ENDIAN_CONVERT(header.dst_size);
if (header.dict_size == 0)
header.dict_size = 1;
if (output)
wr.buffer = output;
else {
wr.bufsize = MIN(header.dst_size, header.dict_size);
wr.buffer = large_malloc(wr.bufsize);
}
if (wr.buffer == NULL)
goto exit_1;
num_probs = LZMA_BASE_SIZE + (LZMA_LIT_SIZE << (lc + lp));
p = (uint16_t *) large_malloc(num_probs * sizeof(*p));
if (p == 0)
goto exit_2;
num_probs = LZMA_LITERAL + (LZMA_LIT_SIZE << (lc + lp));
for (i = 0; i < num_probs; i++)
p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1;
rc_init_code(&rc);
while (get_pos(&wr) < header.dst_size) {
int pos_state = get_pos(&wr) & pos_state_mask;
uint16_t *prob = p + LZMA_IS_MATCH +
(cst.state << LZMA_NUM_POS_BITS_MAX) + pos_state;
if (rc_is_bit_0(&rc, prob))
process_bit0(&wr, &rc, &cst, p, pos_state, prob,
lc, literal_pos_mask);
else {
process_bit1(&wr, &rc, &cst, p, pos_state, prob);
if (cst.rep0 == 0)
break;
}
}
if (posp)
*posp = rc.ptr-rc.buffer;
if (wr.flush)
wr.flush(wr.buffer, wr.buffer_pos);
ret = 0;
large_free(p);
exit_2:
if (!output)
large_free(wr.buffer);
exit_1:
if (!buf)
free(inbuf);
exit_0:
return ret;
}
#define decompress unlzma
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