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bc22c17e AK |
1 | /* Lzma decompressor for Linux kernel. Shamelessly snarfed |
2 | *from busybox 1.1.1 | |
3 | * | |
4 | *Linux kernel adaptation | |
5 | *Copyright (C) 2006 Alain < alain@knaff.lu > | |
6 | * | |
7 | *Based on small lzma deflate implementation/Small range coder | |
8 | *implementation for lzma. | |
9 | *Copyright (C) 2006 Aurelien Jacobs < aurel@gnuage.org > | |
10 | * | |
11 | *Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/) | |
12 | *Copyright (C) 1999-2005 Igor Pavlov | |
13 | * | |
14 | *Copyrights of the parts, see headers below. | |
15 | * | |
16 | * | |
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. | |
21 | * | |
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. | |
26 | * | |
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 | |
30 | */ | |
31 | ||
32 | #ifndef STATIC | |
33 | #include <linux/decompress/unlzma.h> | |
34 | #endif /* STATIC */ | |
35 | ||
36 | #include <linux/decompress/mm.h> | |
37 | ||
38 | #define MIN(a, b) (((a) < (b)) ? (a) : (b)) | |
39 | ||
40 | static long long INIT read_int(unsigned char *ptr, int size) | |
41 | { | |
42 | int i; | |
43 | long long ret = 0; | |
44 | ||
45 | for (i = 0; i < size; i++) | |
46 | ret = (ret << 8) | ptr[size-i-1]; | |
47 | return ret; | |
48 | } | |
49 | ||
50 | #define ENDIAN_CONVERT(x) \ | |
51 | x = (typeof(x))read_int((unsigned char *)&x, sizeof(x)) | |
52 | ||
53 | ||
54 | /* Small range coder implementation for lzma. | |
55 | *Copyright (C) 2006 Aurelien Jacobs < aurel@gnuage.org > | |
56 | * | |
57 | *Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/) | |
58 | *Copyright (c) 1999-2005 Igor Pavlov | |
59 | */ | |
60 | ||
61 | #include <linux/compiler.h> | |
62 | ||
63 | #define LZMA_IOBUF_SIZE 0x10000 | |
64 | ||
65 | struct rc { | |
66 | int (*fill)(void*, unsigned int); | |
67 | uint8_t *ptr; | |
68 | uint8_t *buffer; | |
69 | uint8_t *buffer_end; | |
70 | int buffer_size; | |
71 | uint32_t code; | |
72 | uint32_t range; | |
73 | uint32_t bound; | |
74 | }; | |
75 | ||
76 | ||
77 | #define RC_TOP_BITS 24 | |
78 | #define RC_MOVE_BITS 5 | |
79 | #define RC_MODEL_TOTAL_BITS 11 | |
80 | ||
81 | ||
82 | /* Called twice: once at startup and once in rc_normalize() */ | |
83 | static void INIT rc_read(struct rc *rc) | |
84 | { | |
85 | rc->buffer_size = rc->fill((char *)rc->buffer, LZMA_IOBUF_SIZE); | |
86 | if (rc->buffer_size <= 0) | |
87 | error("unexpected EOF"); | |
88 | rc->ptr = rc->buffer; | |
89 | rc->buffer_end = rc->buffer + rc->buffer_size; | |
90 | } | |
91 | ||
92 | /* Called once */ | |
93 | static inline void INIT rc_init(struct rc *rc, | |
94 | int (*fill)(void*, unsigned int), | |
95 | char *buffer, int buffer_size) | |
96 | { | |
97 | rc->fill = fill; | |
98 | rc->buffer = (uint8_t *)buffer; | |
99 | rc->buffer_size = buffer_size; | |
100 | rc->buffer_end = rc->buffer + rc->buffer_size; | |
101 | rc->ptr = rc->buffer; | |
102 | ||
103 | rc->code = 0; | |
104 | rc->range = 0xFFFFFFFF; | |
105 | } | |
106 | ||
107 | static inline void INIT rc_init_code(struct rc *rc) | |
108 | { | |
109 | int i; | |
110 | ||
111 | for (i = 0; i < 5; i++) { | |
112 | if (rc->ptr >= rc->buffer_end) | |
113 | rc_read(rc); | |
114 | rc->code = (rc->code << 8) | *rc->ptr++; | |
115 | } | |
116 | } | |
117 | ||
118 | ||
119 | /* Called once. TODO: bb_maybe_free() */ | |
120 | static inline void INIT rc_free(struct rc *rc) | |
121 | { | |
122 | free(rc->buffer); | |
123 | } | |
124 | ||
125 | /* Called twice, but one callsite is in inline'd rc_is_bit_0_helper() */ | |
126 | static void INIT rc_do_normalize(struct rc *rc) | |
127 | { | |
128 | if (rc->ptr >= rc->buffer_end) | |
129 | rc_read(rc); | |
130 | rc->range <<= 8; | |
131 | rc->code = (rc->code << 8) | *rc->ptr++; | |
132 | } | |
133 | static inline void INIT rc_normalize(struct rc *rc) | |
134 | { | |
135 | if (rc->range < (1 << RC_TOP_BITS)) | |
136 | rc_do_normalize(rc); | |
137 | } | |
138 | ||
139 | /* Called 9 times */ | |
140 | /* Why rc_is_bit_0_helper exists? | |
141 | *Because we want to always expose (rc->code < rc->bound) to optimizer | |
142 | */ | |
143 | static inline uint32_t INIT rc_is_bit_0_helper(struct rc *rc, uint16_t *p) | |
144 | { | |
145 | rc_normalize(rc); | |
146 | rc->bound = *p * (rc->range >> RC_MODEL_TOTAL_BITS); | |
147 | return rc->bound; | |
148 | } | |
149 | static inline int INIT rc_is_bit_0(struct rc *rc, uint16_t *p) | |
150 | { | |
151 | uint32_t t = rc_is_bit_0_helper(rc, p); | |
152 | return rc->code < t; | |
153 | } | |
154 | ||
155 | /* Called ~10 times, but very small, thus inlined */ | |
156 | static inline void INIT rc_update_bit_0(struct rc *rc, uint16_t *p) | |
157 | { | |
158 | rc->range = rc->bound; | |
159 | *p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS; | |
160 | } | |
161 | static inline void rc_update_bit_1(struct rc *rc, uint16_t *p) | |
162 | { | |
163 | rc->range -= rc->bound; | |
164 | rc->code -= rc->bound; | |
165 | *p -= *p >> RC_MOVE_BITS; | |
166 | } | |
167 | ||
168 | /* Called 4 times in unlzma loop */ | |
169 | static int INIT rc_get_bit(struct rc *rc, uint16_t *p, int *symbol) | |
170 | { | |
171 | if (rc_is_bit_0(rc, p)) { | |
172 | rc_update_bit_0(rc, p); | |
173 | *symbol *= 2; | |
174 | return 0; | |
175 | } else { | |
176 | rc_update_bit_1(rc, p); | |
177 | *symbol = *symbol * 2 + 1; | |
178 | return 1; | |
179 | } | |
180 | } | |
181 | ||
182 | /* Called once */ | |
183 | static inline int INIT rc_direct_bit(struct rc *rc) | |
184 | { | |
185 | rc_normalize(rc); | |
186 | rc->range >>= 1; | |
187 | if (rc->code >= rc->range) { | |
188 | rc->code -= rc->range; | |
189 | return 1; | |
190 | } | |
191 | return 0; | |
192 | } | |
193 | ||
194 | /* Called twice */ | |
195 | static inline void INIT | |
196 | rc_bit_tree_decode(struct rc *rc, uint16_t *p, int num_levels, int *symbol) | |
197 | { | |
198 | int i = num_levels; | |
199 | ||
200 | *symbol = 1; | |
201 | while (i--) | |
202 | rc_get_bit(rc, p + *symbol, symbol); | |
203 | *symbol -= 1 << num_levels; | |
204 | } | |
205 | ||
206 | ||
207 | /* | |
208 | * Small lzma deflate implementation. | |
209 | * Copyright (C) 2006 Aurelien Jacobs < aurel@gnuage.org > | |
210 | * | |
211 | * Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/) | |
212 | * Copyright (C) 1999-2005 Igor Pavlov | |
213 | */ | |
214 | ||
215 | ||
216 | struct lzma_header { | |
217 | uint8_t pos; | |
218 | uint32_t dict_size; | |
219 | uint64_t dst_size; | |
220 | } __attribute__ ((packed)) ; | |
221 | ||
222 | ||
223 | #define LZMA_BASE_SIZE 1846 | |
224 | #define LZMA_LIT_SIZE 768 | |
225 | ||
226 | #define LZMA_NUM_POS_BITS_MAX 4 | |
227 | ||
228 | #define LZMA_LEN_NUM_LOW_BITS 3 | |
229 | #define LZMA_LEN_NUM_MID_BITS 3 | |
230 | #define LZMA_LEN_NUM_HIGH_BITS 8 | |
231 | ||
232 | #define LZMA_LEN_CHOICE 0 | |
233 | #define LZMA_LEN_CHOICE_2 (LZMA_LEN_CHOICE + 1) | |
234 | #define LZMA_LEN_LOW (LZMA_LEN_CHOICE_2 + 1) | |
235 | #define LZMA_LEN_MID (LZMA_LEN_LOW \ | |
236 | + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS))) | |
237 | #define LZMA_LEN_HIGH (LZMA_LEN_MID \ | |
238 | +(1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS))) | |
239 | #define LZMA_NUM_LEN_PROBS (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS)) | |
240 | ||
241 | #define LZMA_NUM_STATES 12 | |
242 | #define LZMA_NUM_LIT_STATES 7 | |
243 | ||
244 | #define LZMA_START_POS_MODEL_INDEX 4 | |
245 | #define LZMA_END_POS_MODEL_INDEX 14 | |
246 | #define LZMA_NUM_FULL_DISTANCES (1 << (LZMA_END_POS_MODEL_INDEX >> 1)) | |
247 | ||
248 | #define LZMA_NUM_POS_SLOT_BITS 6 | |
249 | #define LZMA_NUM_LEN_TO_POS_STATES 4 | |
250 | ||
251 | #define LZMA_NUM_ALIGN_BITS 4 | |
252 | ||
253 | #define LZMA_MATCH_MIN_LEN 2 | |
254 | ||
255 | #define LZMA_IS_MATCH 0 | |
256 | #define LZMA_IS_REP (LZMA_IS_MATCH + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX)) | |
257 | #define LZMA_IS_REP_G0 (LZMA_IS_REP + LZMA_NUM_STATES) | |
258 | #define LZMA_IS_REP_G1 (LZMA_IS_REP_G0 + LZMA_NUM_STATES) | |
259 | #define LZMA_IS_REP_G2 (LZMA_IS_REP_G1 + LZMA_NUM_STATES) | |
260 | #define LZMA_IS_REP_0_LONG (LZMA_IS_REP_G2 + LZMA_NUM_STATES) | |
261 | #define LZMA_POS_SLOT (LZMA_IS_REP_0_LONG \ | |
262 | + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX)) | |
263 | #define LZMA_SPEC_POS (LZMA_POS_SLOT \ | |
264 | +(LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS)) | |
265 | #define LZMA_ALIGN (LZMA_SPEC_POS \ | |
266 | + LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX) | |
267 | #define LZMA_LEN_CODER (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS)) | |
268 | #define LZMA_REP_LEN_CODER (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS) | |
269 | #define LZMA_LITERAL (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS) | |
270 | ||
271 | ||
272 | struct writer { | |
273 | uint8_t *buffer; | |
274 | uint8_t previous_byte; | |
275 | size_t buffer_pos; | |
276 | int bufsize; | |
277 | size_t global_pos; | |
278 | int(*flush)(void*, unsigned int); | |
279 | struct lzma_header *header; | |
280 | }; | |
281 | ||
282 | struct cstate { | |
283 | int state; | |
284 | uint32_t rep0, rep1, rep2, rep3; | |
285 | }; | |
286 | ||
287 | static inline size_t INIT get_pos(struct writer *wr) | |
288 | { | |
289 | return | |
290 | wr->global_pos + wr->buffer_pos; | |
291 | } | |
292 | ||
293 | static inline uint8_t INIT peek_old_byte(struct writer *wr, | |
294 | uint32_t offs) | |
295 | { | |
296 | if (!wr->flush) { | |
297 | int32_t pos; | |
298 | while (offs > wr->header->dict_size) | |
299 | offs -= wr->header->dict_size; | |
300 | pos = wr->buffer_pos - offs; | |
301 | return wr->buffer[pos]; | |
302 | } else { | |
303 | uint32_t pos = wr->buffer_pos - offs; | |
304 | while (pos >= wr->header->dict_size) | |
305 | pos += wr->header->dict_size; | |
306 | return wr->buffer[pos]; | |
307 | } | |
308 | ||
309 | } | |
310 | ||
311 | static inline void INIT write_byte(struct writer *wr, uint8_t byte) | |
312 | { | |
313 | wr->buffer[wr->buffer_pos++] = wr->previous_byte = byte; | |
314 | if (wr->flush && wr->buffer_pos == wr->header->dict_size) { | |
315 | wr->buffer_pos = 0; | |
316 | wr->global_pos += wr->header->dict_size; | |
317 | wr->flush((char *)wr->buffer, wr->header->dict_size); | |
318 | } | |
319 | } | |
320 | ||
321 | ||
322 | static inline void INIT copy_byte(struct writer *wr, uint32_t offs) | |
323 | { | |
324 | write_byte(wr, peek_old_byte(wr, offs)); | |
325 | } | |
326 | ||
327 | static inline void INIT copy_bytes(struct writer *wr, | |
328 | uint32_t rep0, int len) | |
329 | { | |
330 | do { | |
331 | copy_byte(wr, rep0); | |
332 | len--; | |
333 | } while (len != 0 && wr->buffer_pos < wr->header->dst_size); | |
334 | } | |
335 | ||
336 | static inline void INIT process_bit0(struct writer *wr, struct rc *rc, | |
337 | struct cstate *cst, uint16_t *p, | |
338 | int pos_state, uint16_t *prob, | |
339 | int lc, uint32_t literal_pos_mask) { | |
340 | int mi = 1; | |
341 | rc_update_bit_0(rc, prob); | |
342 | prob = (p + LZMA_LITERAL + | |
343 | (LZMA_LIT_SIZE | |
344 | * (((get_pos(wr) & literal_pos_mask) << lc) | |
345 | + (wr->previous_byte >> (8 - lc)))) | |
346 | ); | |
347 | ||
348 | if (cst->state >= LZMA_NUM_LIT_STATES) { | |
349 | int match_byte = peek_old_byte(wr, cst->rep0); | |
350 | do { | |
351 | int bit; | |
352 | uint16_t *prob_lit; | |
353 | ||
354 | match_byte <<= 1; | |
355 | bit = match_byte & 0x100; | |
356 | prob_lit = prob + 0x100 + bit + mi; | |
357 | if (rc_get_bit(rc, prob_lit, &mi)) { | |
358 | if (!bit) | |
359 | break; | |
360 | } else { | |
361 | if (bit) | |
362 | break; | |
363 | } | |
364 | } while (mi < 0x100); | |
365 | } | |
366 | while (mi < 0x100) { | |
367 | uint16_t *prob_lit = prob + mi; | |
368 | rc_get_bit(rc, prob_lit, &mi); | |
369 | } | |
370 | write_byte(wr, mi); | |
371 | if (cst->state < 4) | |
372 | cst->state = 0; | |
373 | else if (cst->state < 10) | |
374 | cst->state -= 3; | |
375 | else | |
376 | cst->state -= 6; | |
377 | } | |
378 | ||
379 | static inline void INIT process_bit1(struct writer *wr, struct rc *rc, | |
380 | struct cstate *cst, uint16_t *p, | |
381 | int pos_state, uint16_t *prob) { | |
382 | int offset; | |
383 | uint16_t *prob_len; | |
384 | int num_bits; | |
385 | int len; | |
386 | ||
387 | rc_update_bit_1(rc, prob); | |
388 | prob = p + LZMA_IS_REP + cst->state; | |
389 | if (rc_is_bit_0(rc, prob)) { | |
390 | rc_update_bit_0(rc, prob); | |
391 | cst->rep3 = cst->rep2; | |
392 | cst->rep2 = cst->rep1; | |
393 | cst->rep1 = cst->rep0; | |
394 | cst->state = cst->state < LZMA_NUM_LIT_STATES ? 0 : 3; | |
395 | prob = p + LZMA_LEN_CODER; | |
396 | } else { | |
397 | rc_update_bit_1(rc, prob); | |
398 | prob = p + LZMA_IS_REP_G0 + cst->state; | |
399 | if (rc_is_bit_0(rc, prob)) { | |
400 | rc_update_bit_0(rc, prob); | |
401 | prob = (p + LZMA_IS_REP_0_LONG | |
402 | + (cst->state << | |
403 | LZMA_NUM_POS_BITS_MAX) + | |
404 | pos_state); | |
405 | if (rc_is_bit_0(rc, prob)) { | |
406 | rc_update_bit_0(rc, prob); | |
407 | ||
408 | cst->state = cst->state < LZMA_NUM_LIT_STATES ? | |
409 | 9 : 11; | |
410 | copy_byte(wr, cst->rep0); | |
411 | return; | |
412 | } else { | |
413 | rc_update_bit_1(rc, prob); | |
414 | } | |
415 | } else { | |
416 | uint32_t distance; | |
417 | ||
418 | rc_update_bit_1(rc, prob); | |
419 | prob = p + LZMA_IS_REP_G1 + cst->state; | |
420 | if (rc_is_bit_0(rc, prob)) { | |
421 | rc_update_bit_0(rc, prob); | |
422 | distance = cst->rep1; | |
423 | } else { | |
424 | rc_update_bit_1(rc, prob); | |
425 | prob = p + LZMA_IS_REP_G2 + cst->state; | |
426 | if (rc_is_bit_0(rc, prob)) { | |
427 | rc_update_bit_0(rc, prob); | |
428 | distance = cst->rep2; | |
429 | } else { | |
430 | rc_update_bit_1(rc, prob); | |
431 | distance = cst->rep3; | |
432 | cst->rep3 = cst->rep2; | |
433 | } | |
434 | cst->rep2 = cst->rep1; | |
435 | } | |
436 | cst->rep1 = cst->rep0; | |
437 | cst->rep0 = distance; | |
438 | } | |
439 | cst->state = cst->state < LZMA_NUM_LIT_STATES ? 8 : 11; | |
440 | prob = p + LZMA_REP_LEN_CODER; | |
441 | } | |
442 | ||
443 | prob_len = prob + LZMA_LEN_CHOICE; | |
444 | if (rc_is_bit_0(rc, prob_len)) { | |
445 | rc_update_bit_0(rc, prob_len); | |
446 | prob_len = (prob + LZMA_LEN_LOW | |
447 | + (pos_state << | |
448 | LZMA_LEN_NUM_LOW_BITS)); | |
449 | offset = 0; | |
450 | num_bits = LZMA_LEN_NUM_LOW_BITS; | |
451 | } else { | |
452 | rc_update_bit_1(rc, prob_len); | |
453 | prob_len = prob + LZMA_LEN_CHOICE_2; | |
454 | if (rc_is_bit_0(rc, prob_len)) { | |
455 | rc_update_bit_0(rc, prob_len); | |
456 | prob_len = (prob + LZMA_LEN_MID | |
457 | + (pos_state << | |
458 | LZMA_LEN_NUM_MID_BITS)); | |
459 | offset = 1 << LZMA_LEN_NUM_LOW_BITS; | |
460 | num_bits = LZMA_LEN_NUM_MID_BITS; | |
461 | } else { | |
462 | rc_update_bit_1(rc, prob_len); | |
463 | prob_len = prob + LZMA_LEN_HIGH; | |
464 | offset = ((1 << LZMA_LEN_NUM_LOW_BITS) | |
465 | + (1 << LZMA_LEN_NUM_MID_BITS)); | |
466 | num_bits = LZMA_LEN_NUM_HIGH_BITS; | |
467 | } | |
468 | } | |
469 | ||
470 | rc_bit_tree_decode(rc, prob_len, num_bits, &len); | |
471 | len += offset; | |
472 | ||
473 | if (cst->state < 4) { | |
474 | int pos_slot; | |
475 | ||
476 | cst->state += LZMA_NUM_LIT_STATES; | |
477 | prob = | |
478 | p + LZMA_POS_SLOT + | |
479 | ((len < | |
480 | LZMA_NUM_LEN_TO_POS_STATES ? len : | |
481 | LZMA_NUM_LEN_TO_POS_STATES - 1) | |
482 | << LZMA_NUM_POS_SLOT_BITS); | |
483 | rc_bit_tree_decode(rc, prob, | |
484 | LZMA_NUM_POS_SLOT_BITS, | |
485 | &pos_slot); | |
486 | if (pos_slot >= LZMA_START_POS_MODEL_INDEX) { | |
487 | int i, mi; | |
488 | num_bits = (pos_slot >> 1) - 1; | |
489 | cst->rep0 = 2 | (pos_slot & 1); | |
490 | if (pos_slot < LZMA_END_POS_MODEL_INDEX) { | |
491 | cst->rep0 <<= num_bits; | |
492 | prob = p + LZMA_SPEC_POS + | |
493 | cst->rep0 - pos_slot - 1; | |
494 | } else { | |
495 | num_bits -= LZMA_NUM_ALIGN_BITS; | |
496 | while (num_bits--) | |
497 | cst->rep0 = (cst->rep0 << 1) | | |
498 | rc_direct_bit(rc); | |
499 | prob = p + LZMA_ALIGN; | |
500 | cst->rep0 <<= LZMA_NUM_ALIGN_BITS; | |
501 | num_bits = LZMA_NUM_ALIGN_BITS; | |
502 | } | |
503 | i = 1; | |
504 | mi = 1; | |
505 | while (num_bits--) { | |
506 | if (rc_get_bit(rc, prob + mi, &mi)) | |
507 | cst->rep0 |= i; | |
508 | i <<= 1; | |
509 | } | |
510 | } else | |
511 | cst->rep0 = pos_slot; | |
512 | if (++(cst->rep0) == 0) | |
513 | return; | |
514 | } | |
515 | ||
516 | len += LZMA_MATCH_MIN_LEN; | |
517 | ||
518 | copy_bytes(wr, cst->rep0, len); | |
519 | } | |
520 | ||
521 | ||
522 | ||
523 | STATIC inline int INIT unlzma(unsigned char *buf, int in_len, | |
524 | int(*fill)(void*, unsigned int), | |
525 | int(*flush)(void*, unsigned int), | |
526 | unsigned char *output, | |
527 | int *posp, | |
528 | void(*error_fn)(char *x) | |
529 | ) | |
530 | { | |
531 | struct lzma_header header; | |
532 | int lc, pb, lp; | |
533 | uint32_t pos_state_mask; | |
534 | uint32_t literal_pos_mask; | |
535 | uint16_t *p; | |
536 | int num_probs; | |
537 | struct rc rc; | |
538 | int i, mi; | |
539 | struct writer wr; | |
540 | struct cstate cst; | |
541 | unsigned char *inbuf; | |
542 | int ret = -1; | |
543 | ||
544 | set_error_fn(error_fn); | |
545 | if (!flush) | |
546 | in_len -= 4; /* Uncompressed size hack active in pre-boot | |
547 | environment */ | |
548 | if (buf) | |
549 | inbuf = buf; | |
550 | else | |
551 | inbuf = malloc(LZMA_IOBUF_SIZE); | |
552 | if (!inbuf) { | |
553 | error("Could not allocate input bufer"); | |
554 | goto exit_0; | |
555 | } | |
556 | ||
557 | cst.state = 0; | |
558 | cst.rep0 = cst.rep1 = cst.rep2 = cst.rep3 = 1; | |
559 | ||
560 | wr.header = &header; | |
561 | wr.flush = flush; | |
562 | wr.global_pos = 0; | |
563 | wr.previous_byte = 0; | |
564 | wr.buffer_pos = 0; | |
565 | ||
566 | rc_init(&rc, fill, inbuf, in_len); | |
567 | ||
568 | for (i = 0; i < sizeof(header); i++) { | |
569 | if (rc.ptr >= rc.buffer_end) | |
570 | rc_read(&rc); | |
571 | ((unsigned char *)&header)[i] = *rc.ptr++; | |
572 | } | |
573 | ||
574 | if (header.pos >= (9 * 5 * 5)) | |
575 | error("bad header"); | |
576 | ||
577 | mi = 0; | |
578 | lc = header.pos; | |
579 | while (lc >= 9) { | |
580 | mi++; | |
581 | lc -= 9; | |
582 | } | |
583 | pb = 0; | |
584 | lp = mi; | |
585 | while (lp >= 5) { | |
586 | pb++; | |
587 | lp -= 5; | |
588 | } | |
589 | pos_state_mask = (1 << pb) - 1; | |
590 | literal_pos_mask = (1 << lp) - 1; | |
591 | ||
592 | ENDIAN_CONVERT(header.dict_size); | |
593 | ENDIAN_CONVERT(header.dst_size); | |
594 | ||
595 | if (header.dict_size == 0) | |
596 | header.dict_size = 1; | |
597 | ||
598 | if (output) | |
599 | wr.buffer = output; | |
600 | else { | |
601 | wr.bufsize = MIN(header.dst_size, header.dict_size); | |
602 | wr.buffer = large_malloc(wr.bufsize); | |
603 | } | |
604 | if (wr.buffer == NULL) | |
605 | goto exit_1; | |
606 | ||
607 | num_probs = LZMA_BASE_SIZE + (LZMA_LIT_SIZE << (lc + lp)); | |
608 | p = (uint16_t *) large_malloc(num_probs * sizeof(*p)); | |
609 | if (p == 0) | |
610 | goto exit_2; | |
611 | num_probs = LZMA_LITERAL + (LZMA_LIT_SIZE << (lc + lp)); | |
612 | for (i = 0; i < num_probs; i++) | |
613 | p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1; | |
614 | ||
615 | rc_init_code(&rc); | |
616 | ||
617 | while (get_pos(&wr) < header.dst_size) { | |
618 | int pos_state = get_pos(&wr) & pos_state_mask; | |
619 | uint16_t *prob = p + LZMA_IS_MATCH + | |
620 | (cst.state << LZMA_NUM_POS_BITS_MAX) + pos_state; | |
621 | if (rc_is_bit_0(&rc, prob)) | |
622 | process_bit0(&wr, &rc, &cst, p, pos_state, prob, | |
623 | lc, literal_pos_mask); | |
624 | else { | |
625 | process_bit1(&wr, &rc, &cst, p, pos_state, prob); | |
626 | if (cst.rep0 == 0) | |
627 | break; | |
628 | } | |
629 | } | |
630 | ||
631 | if (posp) | |
632 | *posp = rc.ptr-rc.buffer; | |
633 | if (wr.flush) | |
634 | wr.flush(wr.buffer, wr.buffer_pos); | |
635 | ret = 0; | |
636 | large_free(p); | |
637 | exit_2: | |
638 | if (!output) | |
639 | large_free(wr.buffer); | |
640 | exit_1: | |
641 | if (!buf) | |
642 | free(inbuf); | |
643 | exit_0: | |
644 | return ret; | |
645 | } | |
646 | ||
647 | #define decompress unlzma |