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
33 #include <linux/decompress/unlzma.h>
36 #include <linux/decompress/mm.h>
37 #include <linux/slab.h>
39 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
41 static long long INIT
read_int(unsigned char *ptr
, int size
)
46 for (i
= 0; i
< size
; i
++)
47 ret
= (ret
<< 8) | ptr
[size
-i
-1];
51 #define ENDIAN_CONVERT(x) \
52 x = (typeof(x))read_int((unsigned char *)&x, sizeof(x))
55 /* Small range coder implementation for lzma.
56 *Copyright (C) 2006 Aurelien Jacobs < aurel@gnuage.org >
58 *Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
59 *Copyright (c) 1999-2005 Igor Pavlov
62 #include <linux/compiler.h>
64 #define LZMA_IOBUF_SIZE 0x10000
67 int (*fill
)(void*, unsigned int);
78 #define RC_TOP_BITS 24
79 #define RC_MOVE_BITS 5
80 #define RC_MODEL_TOTAL_BITS 11
83 /* Called twice: once at startup and once in rc_normalize() */
84 static void INIT
rc_read(struct rc
*rc
)
86 rc
->buffer_size
= rc
->fill((char *)rc
->buffer
, LZMA_IOBUF_SIZE
);
87 if (rc
->buffer_size
<= 0)
88 error("unexpected EOF");
90 rc
->buffer_end
= rc
->buffer
+ rc
->buffer_size
;
94 static inline void INIT
rc_init(struct rc
*rc
,
95 int (*fill
)(void*, unsigned int),
96 char *buffer
, int buffer_size
)
99 rc
->buffer
= (uint8_t *)buffer
;
100 rc
->buffer_size
= buffer_size
;
101 rc
->buffer_end
= rc
->buffer
+ rc
->buffer_size
;
102 rc
->ptr
= rc
->buffer
;
105 rc
->range
= 0xFFFFFFFF;
108 static inline void INIT
rc_init_code(struct rc
*rc
)
112 for (i
= 0; i
< 5; i
++) {
113 if (rc
->ptr
>= rc
->buffer_end
)
115 rc
->code
= (rc
->code
<< 8) | *rc
->ptr
++;
120 /* Called once. TODO: bb_maybe_free() */
121 static inline void INIT
rc_free(struct rc
*rc
)
126 /* Called twice, but one callsite is in inline'd rc_is_bit_0_helper() */
127 static void INIT
rc_do_normalize(struct rc
*rc
)
129 if (rc
->ptr
>= rc
->buffer_end
)
132 rc
->code
= (rc
->code
<< 8) | *rc
->ptr
++;
134 static inline void INIT
rc_normalize(struct rc
*rc
)
136 if (rc
->range
< (1 << RC_TOP_BITS
))
141 /* Why rc_is_bit_0_helper exists?
142 *Because we want to always expose (rc->code < rc->bound) to optimizer
144 static inline uint32_t INIT
rc_is_bit_0_helper(struct rc
*rc
, uint16_t *p
)
147 rc
->bound
= *p
* (rc
->range
>> RC_MODEL_TOTAL_BITS
);
150 static inline int INIT
rc_is_bit_0(struct rc
*rc
, uint16_t *p
)
152 uint32_t t
= rc_is_bit_0_helper(rc
, p
);
156 /* Called ~10 times, but very small, thus inlined */
157 static inline void INIT
rc_update_bit_0(struct rc
*rc
, uint16_t *p
)
159 rc
->range
= rc
->bound
;
160 *p
+= ((1 << RC_MODEL_TOTAL_BITS
) - *p
) >> RC_MOVE_BITS
;
162 static inline void rc_update_bit_1(struct rc
*rc
, uint16_t *p
)
164 rc
->range
-= rc
->bound
;
165 rc
->code
-= rc
->bound
;
166 *p
-= *p
>> RC_MOVE_BITS
;
169 /* Called 4 times in unlzma loop */
170 static int INIT
rc_get_bit(struct rc
*rc
, uint16_t *p
, int *symbol
)
172 if (rc_is_bit_0(rc
, p
)) {
173 rc_update_bit_0(rc
, p
);
177 rc_update_bit_1(rc
, p
);
178 *symbol
= *symbol
* 2 + 1;
184 static inline int INIT
rc_direct_bit(struct rc
*rc
)
188 if (rc
->code
>= rc
->range
) {
189 rc
->code
-= rc
->range
;
196 static inline void INIT
197 rc_bit_tree_decode(struct rc
*rc
, uint16_t *p
, int num_levels
, int *symbol
)
203 rc_get_bit(rc
, p
+ *symbol
, symbol
);
204 *symbol
-= 1 << num_levels
;
209 * Small lzma deflate implementation.
210 * Copyright (C) 2006 Aurelien Jacobs < aurel@gnuage.org >
212 * Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
213 * Copyright (C) 1999-2005 Igor Pavlov
221 } __attribute__ ((packed
)) ;
224 #define LZMA_BASE_SIZE 1846
225 #define LZMA_LIT_SIZE 768
227 #define LZMA_NUM_POS_BITS_MAX 4
229 #define LZMA_LEN_NUM_LOW_BITS 3
230 #define LZMA_LEN_NUM_MID_BITS 3
231 #define LZMA_LEN_NUM_HIGH_BITS 8
233 #define LZMA_LEN_CHOICE 0
234 #define LZMA_LEN_CHOICE_2 (LZMA_LEN_CHOICE + 1)
235 #define LZMA_LEN_LOW (LZMA_LEN_CHOICE_2 + 1)
236 #define LZMA_LEN_MID (LZMA_LEN_LOW \
237 + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS)))
238 #define LZMA_LEN_HIGH (LZMA_LEN_MID \
239 +(1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS)))
240 #define LZMA_NUM_LEN_PROBS (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS))
242 #define LZMA_NUM_STATES 12
243 #define LZMA_NUM_LIT_STATES 7
245 #define LZMA_START_POS_MODEL_INDEX 4
246 #define LZMA_END_POS_MODEL_INDEX 14
247 #define LZMA_NUM_FULL_DISTANCES (1 << (LZMA_END_POS_MODEL_INDEX >> 1))
249 #define LZMA_NUM_POS_SLOT_BITS 6
250 #define LZMA_NUM_LEN_TO_POS_STATES 4
252 #define LZMA_NUM_ALIGN_BITS 4
254 #define LZMA_MATCH_MIN_LEN 2
256 #define LZMA_IS_MATCH 0
257 #define LZMA_IS_REP (LZMA_IS_MATCH + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX))
258 #define LZMA_IS_REP_G0 (LZMA_IS_REP + LZMA_NUM_STATES)
259 #define LZMA_IS_REP_G1 (LZMA_IS_REP_G0 + LZMA_NUM_STATES)
260 #define LZMA_IS_REP_G2 (LZMA_IS_REP_G1 + LZMA_NUM_STATES)
261 #define LZMA_IS_REP_0_LONG (LZMA_IS_REP_G2 + LZMA_NUM_STATES)
262 #define LZMA_POS_SLOT (LZMA_IS_REP_0_LONG \
263 + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX))
264 #define LZMA_SPEC_POS (LZMA_POS_SLOT \
265 +(LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS))
266 #define LZMA_ALIGN (LZMA_SPEC_POS \
267 + LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX)
268 #define LZMA_LEN_CODER (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS))
269 #define LZMA_REP_LEN_CODER (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS)
270 #define LZMA_LITERAL (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS)
275 uint8_t previous_byte
;
279 int(*flush
)(void*, unsigned int);
280 struct lzma_header
*header
;
285 uint32_t rep0
, rep1
, rep2
, rep3
;
288 static inline size_t INIT
get_pos(struct writer
*wr
)
291 wr
->global_pos
+ wr
->buffer_pos
;
294 static inline uint8_t INIT
peek_old_byte(struct writer
*wr
,
299 while (offs
> wr
->header
->dict_size
)
300 offs
-= wr
->header
->dict_size
;
301 pos
= wr
->buffer_pos
- offs
;
302 return wr
->buffer
[pos
];
304 uint32_t pos
= wr
->buffer_pos
- offs
;
305 while (pos
>= wr
->header
->dict_size
)
306 pos
+= wr
->header
->dict_size
;
307 return wr
->buffer
[pos
];
312 static inline void INIT
write_byte(struct writer
*wr
, uint8_t byte
)
314 wr
->buffer
[wr
->buffer_pos
++] = wr
->previous_byte
= byte
;
315 if (wr
->flush
&& wr
->buffer_pos
== wr
->header
->dict_size
) {
317 wr
->global_pos
+= wr
->header
->dict_size
;
318 wr
->flush((char *)wr
->buffer
, wr
->header
->dict_size
);
323 static inline void INIT
copy_byte(struct writer
*wr
, uint32_t offs
)
325 write_byte(wr
, peek_old_byte(wr
, offs
));
328 static inline void INIT
copy_bytes(struct writer
*wr
,
329 uint32_t rep0
, int len
)
334 } while (len
!= 0 && wr
->buffer_pos
< wr
->header
->dst_size
);
337 static inline void INIT
process_bit0(struct writer
*wr
, struct rc
*rc
,
338 struct cstate
*cst
, uint16_t *p
,
339 int pos_state
, uint16_t *prob
,
340 int lc
, uint32_t literal_pos_mask
) {
342 rc_update_bit_0(rc
, prob
);
343 prob
= (p
+ LZMA_LITERAL
+
345 * (((get_pos(wr
) & literal_pos_mask
) << lc
)
346 + (wr
->previous_byte
>> (8 - lc
))))
349 if (cst
->state
>= LZMA_NUM_LIT_STATES
) {
350 int match_byte
= peek_old_byte(wr
, cst
->rep0
);
356 bit
= match_byte
& 0x100;
357 prob_lit
= prob
+ 0x100 + bit
+ mi
;
358 if (rc_get_bit(rc
, prob_lit
, &mi
)) {
365 } while (mi
< 0x100);
368 uint16_t *prob_lit
= prob
+ mi
;
369 rc_get_bit(rc
, prob_lit
, &mi
);
374 else if (cst
->state
< 10)
380 static inline void INIT
process_bit1(struct writer
*wr
, struct rc
*rc
,
381 struct cstate
*cst
, uint16_t *p
,
382 int pos_state
, uint16_t *prob
) {
388 rc_update_bit_1(rc
, prob
);
389 prob
= p
+ LZMA_IS_REP
+ cst
->state
;
390 if (rc_is_bit_0(rc
, prob
)) {
391 rc_update_bit_0(rc
, prob
);
392 cst
->rep3
= cst
->rep2
;
393 cst
->rep2
= cst
->rep1
;
394 cst
->rep1
= cst
->rep0
;
395 cst
->state
= cst
->state
< LZMA_NUM_LIT_STATES
? 0 : 3;
396 prob
= p
+ LZMA_LEN_CODER
;
398 rc_update_bit_1(rc
, prob
);
399 prob
= p
+ LZMA_IS_REP_G0
+ cst
->state
;
400 if (rc_is_bit_0(rc
, prob
)) {
401 rc_update_bit_0(rc
, prob
);
402 prob
= (p
+ LZMA_IS_REP_0_LONG
404 LZMA_NUM_POS_BITS_MAX
) +
406 if (rc_is_bit_0(rc
, prob
)) {
407 rc_update_bit_0(rc
, prob
);
409 cst
->state
= cst
->state
< LZMA_NUM_LIT_STATES
?
411 copy_byte(wr
, cst
->rep0
);
414 rc_update_bit_1(rc
, prob
);
419 rc_update_bit_1(rc
, prob
);
420 prob
= p
+ LZMA_IS_REP_G1
+ cst
->state
;
421 if (rc_is_bit_0(rc
, prob
)) {
422 rc_update_bit_0(rc
, prob
);
423 distance
= cst
->rep1
;
425 rc_update_bit_1(rc
, prob
);
426 prob
= p
+ LZMA_IS_REP_G2
+ cst
->state
;
427 if (rc_is_bit_0(rc
, prob
)) {
428 rc_update_bit_0(rc
, prob
);
429 distance
= cst
->rep2
;
431 rc_update_bit_1(rc
, prob
);
432 distance
= cst
->rep3
;
433 cst
->rep3
= cst
->rep2
;
435 cst
->rep2
= cst
->rep1
;
437 cst
->rep1
= cst
->rep0
;
438 cst
->rep0
= distance
;
440 cst
->state
= cst
->state
< LZMA_NUM_LIT_STATES
? 8 : 11;
441 prob
= p
+ LZMA_REP_LEN_CODER
;
444 prob_len
= prob
+ LZMA_LEN_CHOICE
;
445 if (rc_is_bit_0(rc
, prob_len
)) {
446 rc_update_bit_0(rc
, prob_len
);
447 prob_len
= (prob
+ LZMA_LEN_LOW
449 LZMA_LEN_NUM_LOW_BITS
));
451 num_bits
= LZMA_LEN_NUM_LOW_BITS
;
453 rc_update_bit_1(rc
, prob_len
);
454 prob_len
= prob
+ LZMA_LEN_CHOICE_2
;
455 if (rc_is_bit_0(rc
, prob_len
)) {
456 rc_update_bit_0(rc
, prob_len
);
457 prob_len
= (prob
+ LZMA_LEN_MID
459 LZMA_LEN_NUM_MID_BITS
));
460 offset
= 1 << LZMA_LEN_NUM_LOW_BITS
;
461 num_bits
= LZMA_LEN_NUM_MID_BITS
;
463 rc_update_bit_1(rc
, prob_len
);
464 prob_len
= prob
+ LZMA_LEN_HIGH
;
465 offset
= ((1 << LZMA_LEN_NUM_LOW_BITS
)
466 + (1 << LZMA_LEN_NUM_MID_BITS
));
467 num_bits
= LZMA_LEN_NUM_HIGH_BITS
;
471 rc_bit_tree_decode(rc
, prob_len
, num_bits
, &len
);
474 if (cst
->state
< 4) {
477 cst
->state
+= LZMA_NUM_LIT_STATES
;
481 LZMA_NUM_LEN_TO_POS_STATES
? len
:
482 LZMA_NUM_LEN_TO_POS_STATES
- 1)
483 << LZMA_NUM_POS_SLOT_BITS
);
484 rc_bit_tree_decode(rc
, prob
,
485 LZMA_NUM_POS_SLOT_BITS
,
487 if (pos_slot
>= LZMA_START_POS_MODEL_INDEX
) {
489 num_bits
= (pos_slot
>> 1) - 1;
490 cst
->rep0
= 2 | (pos_slot
& 1);
491 if (pos_slot
< LZMA_END_POS_MODEL_INDEX
) {
492 cst
->rep0
<<= num_bits
;
493 prob
= p
+ LZMA_SPEC_POS
+
494 cst
->rep0
- pos_slot
- 1;
496 num_bits
-= LZMA_NUM_ALIGN_BITS
;
498 cst
->rep0
= (cst
->rep0
<< 1) |
500 prob
= p
+ LZMA_ALIGN
;
501 cst
->rep0
<<= LZMA_NUM_ALIGN_BITS
;
502 num_bits
= LZMA_NUM_ALIGN_BITS
;
507 if (rc_get_bit(rc
, prob
+ mi
, &mi
))
512 cst
->rep0
= pos_slot
;
513 if (++(cst
->rep0
) == 0)
517 len
+= LZMA_MATCH_MIN_LEN
;
519 copy_bytes(wr
, cst
->rep0
, len
);
524 STATIC
inline int INIT
unlzma(unsigned char *buf
, int in_len
,
525 int(*fill
)(void*, unsigned int),
526 int(*flush
)(void*, unsigned int),
527 unsigned char *output
,
529 void(*error_fn
)(char *x
)
532 struct lzma_header header
;
534 uint32_t pos_state_mask
;
535 uint32_t literal_pos_mask
;
542 unsigned char *inbuf
;
545 set_error_fn(error_fn
);
547 in_len
-= 4; /* Uncompressed size hack active in pre-boot
552 inbuf
= malloc(LZMA_IOBUF_SIZE
);
554 error("Could not allocate input bufer");
559 cst
.rep0
= cst
.rep1
= cst
.rep2
= cst
.rep3
= 1;
564 wr
.previous_byte
= 0;
567 rc_init(&rc
, fill
, inbuf
, in_len
);
569 for (i
= 0; i
< sizeof(header
); i
++) {
570 if (rc
.ptr
>= rc
.buffer_end
)
572 ((unsigned char *)&header
)[i
] = *rc
.ptr
++;
575 if (header
.pos
>= (9 * 5 * 5))
590 pos_state_mask
= (1 << pb
) - 1;
591 literal_pos_mask
= (1 << lp
) - 1;
593 ENDIAN_CONVERT(header
.dict_size
);
594 ENDIAN_CONVERT(header
.dst_size
);
596 if (header
.dict_size
== 0)
597 header
.dict_size
= 1;
602 wr
.bufsize
= MIN(header
.dst_size
, header
.dict_size
);
603 wr
.buffer
= large_malloc(wr
.bufsize
);
605 if (wr
.buffer
== NULL
)
608 num_probs
= LZMA_BASE_SIZE
+ (LZMA_LIT_SIZE
<< (lc
+ lp
));
609 p
= (uint16_t *) large_malloc(num_probs
* sizeof(*p
));
612 num_probs
= LZMA_LITERAL
+ (LZMA_LIT_SIZE
<< (lc
+ lp
));
613 for (i
= 0; i
< num_probs
; i
++)
614 p
[i
] = (1 << RC_MODEL_TOTAL_BITS
) >> 1;
618 while (get_pos(&wr
) < header
.dst_size
) {
619 int pos_state
= get_pos(&wr
) & pos_state_mask
;
620 uint16_t *prob
= p
+ LZMA_IS_MATCH
+
621 (cst
.state
<< LZMA_NUM_POS_BITS_MAX
) + pos_state
;
622 if (rc_is_bit_0(&rc
, prob
))
623 process_bit0(&wr
, &rc
, &cst
, p
, pos_state
, prob
,
624 lc
, literal_pos_mask
);
626 process_bit1(&wr
, &rc
, &cst
, p
, pos_state
, prob
);
633 *posp
= rc
.ptr
-rc
.buffer
;
635 wr
.flush(wr
.buffer
, wr
.buffer_pos
);
640 large_free(wr
.buffer
);
648 #define decompress unlzma