1 /* Lzma decompressor for Linux kernel. Shamelessly snarfed
4 *Linux kernel adaptation
5 *Copyright (C) 2006 Alain < alain@knaff.lu >
7 *Based on small lzma deflate implementation/Small range coder
8 *implementation for lzma.
9 *Copyright (C) 2006 Aurelien Jacobs < aurel@gnuage.org >
11 *Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
12 *Copyright (C) 1999-2005 Igor Pavlov
14 *Copyrights of the parts, see headers below.
17 *This program is free software; you can redistribute it and/or
18 *modify it under the terms of the GNU Lesser General Public
19 *License as published by the Free Software Foundation; either
20 *version 2.1 of the License, or (at your option) any later version.
22 *This program is distributed in the hope that it will be useful,
23 *but WITHOUT ANY WARRANTY; without even the implied warranty of
24 *MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
25 *Lesser General Public License for more details.
27 *You should have received a copy of the GNU Lesser General Public
28 *License along with this library; if not, write to the Free Software
29 *Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
35 #include <linux/decompress/unlzma.h>
38 #include <linux/decompress/mm.h>
40 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
42 static long long INIT
read_int(unsigned char *ptr
, int size
)
47 for (i
= 0; i
< size
; i
++)
48 ret
= (ret
<< 8) | ptr
[size
-i
-1];
52 #define ENDIAN_CONVERT(x) \
53 x = (typeof(x))read_int((unsigned char *)&x, sizeof(x))
56 /* Small range coder implementation for lzma.
57 *Copyright (C) 2006 Aurelien Jacobs < aurel@gnuage.org >
59 *Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
60 *Copyright (c) 1999-2005 Igor Pavlov
63 #include <linux/compiler.h>
65 #define LZMA_IOBUF_SIZE 0x10000
68 int (*fill
)(void*, unsigned int);
76 void (*error
)(char *);
80 #define RC_TOP_BITS 24
81 #define RC_MOVE_BITS 5
82 #define RC_MODEL_TOTAL_BITS 11
85 static int INIT
nofill(void *buffer
, unsigned int len
)
90 /* Called twice: once at startup and once in rc_normalize() */
91 static void INIT
rc_read(struct rc
*rc
)
93 rc
->buffer_size
= rc
->fill((char *)rc
->buffer
, LZMA_IOBUF_SIZE
);
94 if (rc
->buffer_size
<= 0)
95 rc
->error("unexpected EOF");
97 rc
->buffer_end
= rc
->buffer
+ rc
->buffer_size
;
101 static inline void INIT
rc_init(struct rc
*rc
,
102 int (*fill
)(void*, unsigned int),
103 char *buffer
, int buffer_size
)
109 rc
->buffer
= (uint8_t *)buffer
;
110 rc
->buffer_size
= buffer_size
;
111 rc
->buffer_end
= rc
->buffer
+ rc
->buffer_size
;
112 rc
->ptr
= rc
->buffer
;
115 rc
->range
= 0xFFFFFFFF;
118 static inline void INIT
rc_init_code(struct rc
*rc
)
122 for (i
= 0; i
< 5; i
++) {
123 if (rc
->ptr
>= rc
->buffer_end
)
125 rc
->code
= (rc
->code
<< 8) | *rc
->ptr
++;
130 /* Called twice, but one callsite is in inline'd rc_is_bit_0_helper() */
131 static void INIT
rc_do_normalize(struct rc
*rc
)
133 if (rc
->ptr
>= rc
->buffer_end
)
136 rc
->code
= (rc
->code
<< 8) | *rc
->ptr
++;
138 static inline void INIT
rc_normalize(struct rc
*rc
)
140 if (rc
->range
< (1 << RC_TOP_BITS
))
145 /* Why rc_is_bit_0_helper exists?
146 *Because we want to always expose (rc->code < rc->bound) to optimizer
148 static inline uint32_t INIT
rc_is_bit_0_helper(struct rc
*rc
, uint16_t *p
)
151 rc
->bound
= *p
* (rc
->range
>> RC_MODEL_TOTAL_BITS
);
154 static inline int INIT
rc_is_bit_0(struct rc
*rc
, uint16_t *p
)
156 uint32_t t
= rc_is_bit_0_helper(rc
, p
);
160 /* Called ~10 times, but very small, thus inlined */
161 static inline void INIT
rc_update_bit_0(struct rc
*rc
, uint16_t *p
)
163 rc
->range
= rc
->bound
;
164 *p
+= ((1 << RC_MODEL_TOTAL_BITS
) - *p
) >> RC_MOVE_BITS
;
166 static inline void INIT
rc_update_bit_1(struct rc
*rc
, uint16_t *p
)
168 rc
->range
-= rc
->bound
;
169 rc
->code
-= rc
->bound
;
170 *p
-= *p
>> RC_MOVE_BITS
;
173 /* Called 4 times in unlzma loop */
174 static int INIT
rc_get_bit(struct rc
*rc
, uint16_t *p
, int *symbol
)
176 if (rc_is_bit_0(rc
, p
)) {
177 rc_update_bit_0(rc
, p
);
181 rc_update_bit_1(rc
, p
);
182 *symbol
= *symbol
* 2 + 1;
188 static inline int INIT
rc_direct_bit(struct rc
*rc
)
192 if (rc
->code
>= rc
->range
) {
193 rc
->code
-= rc
->range
;
200 static inline void INIT
201 rc_bit_tree_decode(struct rc
*rc
, uint16_t *p
, int num_levels
, int *symbol
)
207 rc_get_bit(rc
, p
+ *symbol
, symbol
);
208 *symbol
-= 1 << num_levels
;
213 * Small lzma deflate implementation.
214 * Copyright (C) 2006 Aurelien Jacobs < aurel@gnuage.org >
216 * Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
217 * Copyright (C) 1999-2005 Igor Pavlov
225 } __attribute__ ((packed
)) ;
228 #define LZMA_BASE_SIZE 1846
229 #define LZMA_LIT_SIZE 768
231 #define LZMA_NUM_POS_BITS_MAX 4
233 #define LZMA_LEN_NUM_LOW_BITS 3
234 #define LZMA_LEN_NUM_MID_BITS 3
235 #define LZMA_LEN_NUM_HIGH_BITS 8
237 #define LZMA_LEN_CHOICE 0
238 #define LZMA_LEN_CHOICE_2 (LZMA_LEN_CHOICE + 1)
239 #define LZMA_LEN_LOW (LZMA_LEN_CHOICE_2 + 1)
240 #define LZMA_LEN_MID (LZMA_LEN_LOW \
241 + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS)))
242 #define LZMA_LEN_HIGH (LZMA_LEN_MID \
243 +(1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS)))
244 #define LZMA_NUM_LEN_PROBS (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS))
246 #define LZMA_NUM_STATES 12
247 #define LZMA_NUM_LIT_STATES 7
249 #define LZMA_START_POS_MODEL_INDEX 4
250 #define LZMA_END_POS_MODEL_INDEX 14
251 #define LZMA_NUM_FULL_DISTANCES (1 << (LZMA_END_POS_MODEL_INDEX >> 1))
253 #define LZMA_NUM_POS_SLOT_BITS 6
254 #define LZMA_NUM_LEN_TO_POS_STATES 4
256 #define LZMA_NUM_ALIGN_BITS 4
258 #define LZMA_MATCH_MIN_LEN 2
260 #define LZMA_IS_MATCH 0
261 #define LZMA_IS_REP (LZMA_IS_MATCH + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX))
262 #define LZMA_IS_REP_G0 (LZMA_IS_REP + LZMA_NUM_STATES)
263 #define LZMA_IS_REP_G1 (LZMA_IS_REP_G0 + LZMA_NUM_STATES)
264 #define LZMA_IS_REP_G2 (LZMA_IS_REP_G1 + LZMA_NUM_STATES)
265 #define LZMA_IS_REP_0_LONG (LZMA_IS_REP_G2 + LZMA_NUM_STATES)
266 #define LZMA_POS_SLOT (LZMA_IS_REP_0_LONG \
267 + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX))
268 #define LZMA_SPEC_POS (LZMA_POS_SLOT \
269 +(LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS))
270 #define LZMA_ALIGN (LZMA_SPEC_POS \
271 + LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX)
272 #define LZMA_LEN_CODER (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS))
273 #define LZMA_REP_LEN_CODER (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS)
274 #define LZMA_LITERAL (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS)
279 uint8_t previous_byte
;
283 int(*flush
)(void*, unsigned int);
284 struct lzma_header
*header
;
289 uint32_t rep0
, rep1
, rep2
, rep3
;
292 static inline size_t INIT
get_pos(struct writer
*wr
)
295 wr
->global_pos
+ wr
->buffer_pos
;
298 static inline uint8_t INIT
peek_old_byte(struct writer
*wr
,
303 while (offs
> wr
->header
->dict_size
)
304 offs
-= wr
->header
->dict_size
;
305 pos
= wr
->buffer_pos
- offs
;
306 return wr
->buffer
[pos
];
308 uint32_t pos
= wr
->buffer_pos
- offs
;
309 while (pos
>= wr
->header
->dict_size
)
310 pos
+= wr
->header
->dict_size
;
311 return wr
->buffer
[pos
];
316 static inline void INIT
write_byte(struct writer
*wr
, uint8_t byte
)
318 wr
->buffer
[wr
->buffer_pos
++] = wr
->previous_byte
= byte
;
319 if (wr
->flush
&& wr
->buffer_pos
== wr
->header
->dict_size
) {
321 wr
->global_pos
+= wr
->header
->dict_size
;
322 wr
->flush((char *)wr
->buffer
, wr
->header
->dict_size
);
327 static inline void INIT
copy_byte(struct writer
*wr
, uint32_t offs
)
329 write_byte(wr
, peek_old_byte(wr
, offs
));
332 static inline void INIT
copy_bytes(struct writer
*wr
,
333 uint32_t rep0
, int len
)
338 } while (len
!= 0 && wr
->buffer_pos
< wr
->header
->dst_size
);
341 static inline void INIT
process_bit0(struct writer
*wr
, struct rc
*rc
,
342 struct cstate
*cst
, uint16_t *p
,
343 int pos_state
, uint16_t *prob
,
344 int lc
, uint32_t literal_pos_mask
) {
346 rc_update_bit_0(rc
, prob
);
347 prob
= (p
+ LZMA_LITERAL
+
349 * (((get_pos(wr
) & literal_pos_mask
) << lc
)
350 + (wr
->previous_byte
>> (8 - lc
))))
353 if (cst
->state
>= LZMA_NUM_LIT_STATES
) {
354 int match_byte
= peek_old_byte(wr
, cst
->rep0
);
360 bit
= match_byte
& 0x100;
361 prob_lit
= prob
+ 0x100 + bit
+ mi
;
362 if (rc_get_bit(rc
, prob_lit
, &mi
)) {
369 } while (mi
< 0x100);
372 uint16_t *prob_lit
= prob
+ mi
;
373 rc_get_bit(rc
, prob_lit
, &mi
);
378 else if (cst
->state
< 10)
384 static inline void INIT
process_bit1(struct writer
*wr
, struct rc
*rc
,
385 struct cstate
*cst
, uint16_t *p
,
386 int pos_state
, uint16_t *prob
) {
392 rc_update_bit_1(rc
, prob
);
393 prob
= p
+ LZMA_IS_REP
+ cst
->state
;
394 if (rc_is_bit_0(rc
, prob
)) {
395 rc_update_bit_0(rc
, prob
);
396 cst
->rep3
= cst
->rep2
;
397 cst
->rep2
= cst
->rep1
;
398 cst
->rep1
= cst
->rep0
;
399 cst
->state
= cst
->state
< LZMA_NUM_LIT_STATES
? 0 : 3;
400 prob
= p
+ LZMA_LEN_CODER
;
402 rc_update_bit_1(rc
, prob
);
403 prob
= p
+ LZMA_IS_REP_G0
+ cst
->state
;
404 if (rc_is_bit_0(rc
, prob
)) {
405 rc_update_bit_0(rc
, prob
);
406 prob
= (p
+ LZMA_IS_REP_0_LONG
408 LZMA_NUM_POS_BITS_MAX
) +
410 if (rc_is_bit_0(rc
, prob
)) {
411 rc_update_bit_0(rc
, prob
);
413 cst
->state
= cst
->state
< LZMA_NUM_LIT_STATES
?
415 copy_byte(wr
, cst
->rep0
);
418 rc_update_bit_1(rc
, prob
);
423 rc_update_bit_1(rc
, prob
);
424 prob
= p
+ LZMA_IS_REP_G1
+ cst
->state
;
425 if (rc_is_bit_0(rc
, prob
)) {
426 rc_update_bit_0(rc
, prob
);
427 distance
= cst
->rep1
;
429 rc_update_bit_1(rc
, prob
);
430 prob
= p
+ LZMA_IS_REP_G2
+ cst
->state
;
431 if (rc_is_bit_0(rc
, prob
)) {
432 rc_update_bit_0(rc
, prob
);
433 distance
= cst
->rep2
;
435 rc_update_bit_1(rc
, prob
);
436 distance
= cst
->rep3
;
437 cst
->rep3
= cst
->rep2
;
439 cst
->rep2
= cst
->rep1
;
441 cst
->rep1
= cst
->rep0
;
442 cst
->rep0
= distance
;
444 cst
->state
= cst
->state
< LZMA_NUM_LIT_STATES
? 8 : 11;
445 prob
= p
+ LZMA_REP_LEN_CODER
;
448 prob_len
= prob
+ LZMA_LEN_CHOICE
;
449 if (rc_is_bit_0(rc
, prob_len
)) {
450 rc_update_bit_0(rc
, prob_len
);
451 prob_len
= (prob
+ LZMA_LEN_LOW
453 LZMA_LEN_NUM_LOW_BITS
));
455 num_bits
= LZMA_LEN_NUM_LOW_BITS
;
457 rc_update_bit_1(rc
, prob_len
);
458 prob_len
= prob
+ LZMA_LEN_CHOICE_2
;
459 if (rc_is_bit_0(rc
, prob_len
)) {
460 rc_update_bit_0(rc
, prob_len
);
461 prob_len
= (prob
+ LZMA_LEN_MID
463 LZMA_LEN_NUM_MID_BITS
));
464 offset
= 1 << LZMA_LEN_NUM_LOW_BITS
;
465 num_bits
= LZMA_LEN_NUM_MID_BITS
;
467 rc_update_bit_1(rc
, prob_len
);
468 prob_len
= prob
+ LZMA_LEN_HIGH
;
469 offset
= ((1 << LZMA_LEN_NUM_LOW_BITS
)
470 + (1 << LZMA_LEN_NUM_MID_BITS
));
471 num_bits
= LZMA_LEN_NUM_HIGH_BITS
;
475 rc_bit_tree_decode(rc
, prob_len
, num_bits
, &len
);
478 if (cst
->state
< 4) {
481 cst
->state
+= LZMA_NUM_LIT_STATES
;
485 LZMA_NUM_LEN_TO_POS_STATES
? len
:
486 LZMA_NUM_LEN_TO_POS_STATES
- 1)
487 << LZMA_NUM_POS_SLOT_BITS
);
488 rc_bit_tree_decode(rc
, prob
,
489 LZMA_NUM_POS_SLOT_BITS
,
491 if (pos_slot
>= LZMA_START_POS_MODEL_INDEX
) {
493 num_bits
= (pos_slot
>> 1) - 1;
494 cst
->rep0
= 2 | (pos_slot
& 1);
495 if (pos_slot
< LZMA_END_POS_MODEL_INDEX
) {
496 cst
->rep0
<<= num_bits
;
497 prob
= p
+ LZMA_SPEC_POS
+
498 cst
->rep0
- pos_slot
- 1;
500 num_bits
-= LZMA_NUM_ALIGN_BITS
;
502 cst
->rep0
= (cst
->rep0
<< 1) |
504 prob
= p
+ LZMA_ALIGN
;
505 cst
->rep0
<<= LZMA_NUM_ALIGN_BITS
;
506 num_bits
= LZMA_NUM_ALIGN_BITS
;
511 if (rc_get_bit(rc
, prob
+ mi
, &mi
))
516 cst
->rep0
= pos_slot
;
517 if (++(cst
->rep0
) == 0)
521 len
+= LZMA_MATCH_MIN_LEN
;
523 copy_bytes(wr
, cst
->rep0
, len
);
528 STATIC
inline int INIT
unlzma(unsigned char *buf
, int in_len
,
529 int(*fill
)(void*, unsigned int),
530 int(*flush
)(void*, unsigned int),
531 unsigned char *output
,
533 void(*error
)(char *x
)
536 struct lzma_header header
;
538 uint32_t pos_state_mask
;
539 uint32_t literal_pos_mask
;
546 unsigned char *inbuf
;
554 inbuf
= malloc(LZMA_IOBUF_SIZE
);
556 error("Could not allocate input bufer");
561 cst
.rep0
= cst
.rep1
= cst
.rep2
= cst
.rep3
= 1;
566 wr
.previous_byte
= 0;
569 rc_init(&rc
, fill
, inbuf
, in_len
);
571 for (i
= 0; i
< sizeof(header
); i
++) {
572 if (rc
.ptr
>= rc
.buffer_end
)
574 ((unsigned char *)&header
)[i
] = *rc
.ptr
++;
577 if (header
.pos
>= (9 * 5 * 5))
592 pos_state_mask
= (1 << pb
) - 1;
593 literal_pos_mask
= (1 << lp
) - 1;
595 ENDIAN_CONVERT(header
.dict_size
);
596 ENDIAN_CONVERT(header
.dst_size
);
598 if (header
.dict_size
== 0)
599 header
.dict_size
= 1;
604 wr
.bufsize
= MIN(header
.dst_size
, header
.dict_size
);
605 wr
.buffer
= large_malloc(wr
.bufsize
);
607 if (wr
.buffer
== NULL
)
610 num_probs
= LZMA_BASE_SIZE
+ (LZMA_LIT_SIZE
<< (lc
+ lp
));
611 p
= (uint16_t *) large_malloc(num_probs
* sizeof(*p
));
614 num_probs
= LZMA_LITERAL
+ (LZMA_LIT_SIZE
<< (lc
+ lp
));
615 for (i
= 0; i
< num_probs
; i
++)
616 p
[i
] = (1 << RC_MODEL_TOTAL_BITS
) >> 1;
620 while (get_pos(&wr
) < header
.dst_size
) {
621 int pos_state
= get_pos(&wr
) & pos_state_mask
;
622 uint16_t *prob
= p
+ LZMA_IS_MATCH
+
623 (cst
.state
<< LZMA_NUM_POS_BITS_MAX
) + pos_state
;
624 if (rc_is_bit_0(&rc
, prob
))
625 process_bit0(&wr
, &rc
, &cst
, p
, pos_state
, prob
,
626 lc
, literal_pos_mask
);
628 process_bit1(&wr
, &rc
, &cst
, p
, pos_state
, prob
);
635 *posp
= rc
.ptr
-rc
.buffer
;
637 wr
.flush(wr
.buffer
, wr
.buffer_pos
);
642 large_free(wr
.buffer
);
651 STATIC
int INIT
decompress(unsigned char *buf
, int in_len
,
652 int(*fill
)(void*, unsigned int),
653 int(*flush
)(void*, unsigned int),
654 unsigned char *output
,
656 void(*error
)(char *x
)
659 return unlzma(buf
, in_len
- 4, fill
, flush
, output
, posp
, error
);