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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> | |
e65a1b7c | 37 | #include <linux/slab.h> |
bc22c17e AK |
38 | |
39 | #define MIN(a, b) (((a) < (b)) ? (a) : (b)) | |
40 | ||
41 | static long long INIT read_int(unsigned char *ptr, int size) | |
42 | { | |
43 | int i; | |
44 | long long ret = 0; | |
45 | ||
46 | for (i = 0; i < size; i++) | |
47 | ret = (ret << 8) | ptr[size-i-1]; | |
48 | return ret; | |
49 | } | |
50 | ||
51 | #define ENDIAN_CONVERT(x) \ | |
52 | x = (typeof(x))read_int((unsigned char *)&x, sizeof(x)) | |
53 | ||
54 | ||
55 | /* Small range coder implementation for lzma. | |
56 | *Copyright (C) 2006 Aurelien Jacobs < aurel@gnuage.org > | |
57 | * | |
58 | *Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/) | |
59 | *Copyright (c) 1999-2005 Igor Pavlov | |
60 | */ | |
61 | ||
62 | #include <linux/compiler.h> | |
63 | ||
64 | #define LZMA_IOBUF_SIZE 0x10000 | |
65 | ||
66 | struct rc { | |
67 | int (*fill)(void*, unsigned int); | |
68 | uint8_t *ptr; | |
69 | uint8_t *buffer; | |
70 | uint8_t *buffer_end; | |
71 | int buffer_size; | |
72 | uint32_t code; | |
73 | uint32_t range; | |
74 | uint32_t bound; | |
75 | }; | |
76 | ||
77 | ||
78 | #define RC_TOP_BITS 24 | |
79 | #define RC_MOVE_BITS 5 | |
80 | #define RC_MODEL_TOTAL_BITS 11 | |
81 | ||
82 | ||
83 | /* Called twice: once at startup and once in rc_normalize() */ | |
84 | static void INIT rc_read(struct rc *rc) | |
85 | { | |
86 | rc->buffer_size = rc->fill((char *)rc->buffer, LZMA_IOBUF_SIZE); | |
87 | if (rc->buffer_size <= 0) | |
88 | error("unexpected EOF"); | |
89 | rc->ptr = rc->buffer; | |
90 | rc->buffer_end = rc->buffer + rc->buffer_size; | |
91 | } | |
92 | ||
93 | /* Called once */ | |
94 | static inline void INIT rc_init(struct rc *rc, | |
95 | int (*fill)(void*, unsigned int), | |
96 | char *buffer, int buffer_size) | |
97 | { | |
98 | rc->fill = fill; | |
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; | |
103 | ||
104 | rc->code = 0; | |
105 | rc->range = 0xFFFFFFFF; | |
106 | } | |
107 | ||
108 | static inline void INIT rc_init_code(struct rc *rc) | |
109 | { | |
110 | int i; | |
111 | ||
112 | for (i = 0; i < 5; i++) { | |
113 | if (rc->ptr >= rc->buffer_end) | |
114 | rc_read(rc); | |
115 | rc->code = (rc->code << 8) | *rc->ptr++; | |
116 | } | |
117 | } | |
118 | ||
119 | ||
120 | /* Called once. TODO: bb_maybe_free() */ | |
121 | static inline void INIT rc_free(struct rc *rc) | |
122 | { | |
123 | free(rc->buffer); | |
124 | } | |
125 | ||
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) | |
128 | { | |
129 | if (rc->ptr >= rc->buffer_end) | |
130 | rc_read(rc); | |
131 | rc->range <<= 8; | |
132 | rc->code = (rc->code << 8) | *rc->ptr++; | |
133 | } | |
134 | static inline void INIT rc_normalize(struct rc *rc) | |
135 | { | |
136 | if (rc->range < (1 << RC_TOP_BITS)) | |
137 | rc_do_normalize(rc); | |
138 | } | |
139 | ||
140 | /* Called 9 times */ | |
141 | /* Why rc_is_bit_0_helper exists? | |
142 | *Because we want to always expose (rc->code < rc->bound) to optimizer | |
143 | */ | |
144 | static inline uint32_t INIT rc_is_bit_0_helper(struct rc *rc, uint16_t *p) | |
145 | { | |
146 | rc_normalize(rc); | |
147 | rc->bound = *p * (rc->range >> RC_MODEL_TOTAL_BITS); | |
148 | return rc->bound; | |
149 | } | |
150 | static inline int INIT rc_is_bit_0(struct rc *rc, uint16_t *p) | |
151 | { | |
152 | uint32_t t = rc_is_bit_0_helper(rc, p); | |
153 | return rc->code < t; | |
154 | } | |
155 | ||
156 | /* Called ~10 times, but very small, thus inlined */ | |
157 | static inline void INIT rc_update_bit_0(struct rc *rc, uint16_t *p) | |
158 | { | |
159 | rc->range = rc->bound; | |
160 | *p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS; | |
161 | } | |
162 | static inline void rc_update_bit_1(struct rc *rc, uint16_t *p) | |
163 | { | |
164 | rc->range -= rc->bound; | |
165 | rc->code -= rc->bound; | |
166 | *p -= *p >> RC_MOVE_BITS; | |
167 | } | |
168 | ||
169 | /* Called 4 times in unlzma loop */ | |
170 | static int INIT rc_get_bit(struct rc *rc, uint16_t *p, int *symbol) | |
171 | { | |
172 | if (rc_is_bit_0(rc, p)) { | |
173 | rc_update_bit_0(rc, p); | |
174 | *symbol *= 2; | |
175 | return 0; | |
176 | } else { | |
177 | rc_update_bit_1(rc, p); | |
178 | *symbol = *symbol * 2 + 1; | |
179 | return 1; | |
180 | } | |
181 | } | |
182 | ||
183 | /* Called once */ | |
184 | static inline int INIT rc_direct_bit(struct rc *rc) | |
185 | { | |
186 | rc_normalize(rc); | |
187 | rc->range >>= 1; | |
188 | if (rc->code >= rc->range) { | |
189 | rc->code -= rc->range; | |
190 | return 1; | |
191 | } | |
192 | return 0; | |
193 | } | |
194 | ||
195 | /* Called twice */ | |
196 | static inline void INIT | |
197 | rc_bit_tree_decode(struct rc *rc, uint16_t *p, int num_levels, int *symbol) | |
198 | { | |
199 | int i = num_levels; | |
200 | ||
201 | *symbol = 1; | |
202 | while (i--) | |
203 | rc_get_bit(rc, p + *symbol, symbol); | |
204 | *symbol -= 1 << num_levels; | |
205 | } | |
206 | ||
207 | ||
208 | /* | |
209 | * Small lzma deflate implementation. | |
210 | * Copyright (C) 2006 Aurelien Jacobs < aurel@gnuage.org > | |
211 | * | |
212 | * Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/) | |
213 | * Copyright (C) 1999-2005 Igor Pavlov | |
214 | */ | |
215 | ||
216 | ||
217 | struct lzma_header { | |
218 | uint8_t pos; | |
219 | uint32_t dict_size; | |
220 | uint64_t dst_size; | |
221 | } __attribute__ ((packed)) ; | |
222 | ||
223 | ||
224 | #define LZMA_BASE_SIZE 1846 | |
225 | #define LZMA_LIT_SIZE 768 | |
226 | ||
227 | #define LZMA_NUM_POS_BITS_MAX 4 | |
228 | ||
229 | #define LZMA_LEN_NUM_LOW_BITS 3 | |
230 | #define LZMA_LEN_NUM_MID_BITS 3 | |
231 | #define LZMA_LEN_NUM_HIGH_BITS 8 | |
232 | ||
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)) | |
241 | ||
242 | #define LZMA_NUM_STATES 12 | |
243 | #define LZMA_NUM_LIT_STATES 7 | |
244 | ||
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)) | |
248 | ||
249 | #define LZMA_NUM_POS_SLOT_BITS 6 | |
250 | #define LZMA_NUM_LEN_TO_POS_STATES 4 | |
251 | ||
252 | #define LZMA_NUM_ALIGN_BITS 4 | |
253 | ||
254 | #define LZMA_MATCH_MIN_LEN 2 | |
255 | ||
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) | |
271 | ||
272 | ||
273 | struct writer { | |
274 | uint8_t *buffer; | |
275 | uint8_t previous_byte; | |
276 | size_t buffer_pos; | |
277 | int bufsize; | |
278 | size_t global_pos; | |
279 | int(*flush)(void*, unsigned int); | |
280 | struct lzma_header *header; | |
281 | }; | |
282 | ||
283 | struct cstate { | |
284 | int state; | |
285 | uint32_t rep0, rep1, rep2, rep3; | |
286 | }; | |
287 | ||
288 | static inline size_t INIT get_pos(struct writer *wr) | |
289 | { | |
290 | return | |
291 | wr->global_pos + wr->buffer_pos; | |
292 | } | |
293 | ||
294 | static inline uint8_t INIT peek_old_byte(struct writer *wr, | |
295 | uint32_t offs) | |
296 | { | |
297 | if (!wr->flush) { | |
298 | int32_t pos; | |
299 | while (offs > wr->header->dict_size) | |
300 | offs -= wr->header->dict_size; | |
301 | pos = wr->buffer_pos - offs; | |
302 | return wr->buffer[pos]; | |
303 | } else { | |
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]; | |
308 | } | |
309 | ||
310 | } | |
311 | ||
312 | static inline void INIT write_byte(struct writer *wr, uint8_t byte) | |
313 | { | |
314 | wr->buffer[wr->buffer_pos++] = wr->previous_byte = byte; | |
315 | if (wr->flush && wr->buffer_pos == wr->header->dict_size) { | |
316 | wr->buffer_pos = 0; | |
317 | wr->global_pos += wr->header->dict_size; | |
318 | wr->flush((char *)wr->buffer, wr->header->dict_size); | |
319 | } | |
320 | } | |
321 | ||
322 | ||
323 | static inline void INIT copy_byte(struct writer *wr, uint32_t offs) | |
324 | { | |
325 | write_byte(wr, peek_old_byte(wr, offs)); | |
326 | } | |
327 | ||
328 | static inline void INIT copy_bytes(struct writer *wr, | |
329 | uint32_t rep0, int len) | |
330 | { | |
331 | do { | |
332 | copy_byte(wr, rep0); | |
333 | len--; | |
334 | } while (len != 0 && wr->buffer_pos < wr->header->dst_size); | |
335 | } | |
336 | ||
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) { | |
341 | int mi = 1; | |
342 | rc_update_bit_0(rc, prob); | |
343 | prob = (p + LZMA_LITERAL + | |
344 | (LZMA_LIT_SIZE | |
345 | * (((get_pos(wr) & literal_pos_mask) << lc) | |
346 | + (wr->previous_byte >> (8 - lc)))) | |
347 | ); | |
348 | ||
349 | if (cst->state >= LZMA_NUM_LIT_STATES) { | |
350 | int match_byte = peek_old_byte(wr, cst->rep0); | |
351 | do { | |
352 | int bit; | |
353 | uint16_t *prob_lit; | |
354 | ||
355 | match_byte <<= 1; | |
356 | bit = match_byte & 0x100; | |
357 | prob_lit = prob + 0x100 + bit + mi; | |
358 | if (rc_get_bit(rc, prob_lit, &mi)) { | |
359 | if (!bit) | |
360 | break; | |
361 | } else { | |
362 | if (bit) | |
363 | break; | |
364 | } | |
365 | } while (mi < 0x100); | |
366 | } | |
367 | while (mi < 0x100) { | |
368 | uint16_t *prob_lit = prob + mi; | |
369 | rc_get_bit(rc, prob_lit, &mi); | |
370 | } | |
371 | write_byte(wr, mi); | |
372 | if (cst->state < 4) | |
373 | cst->state = 0; | |
374 | else if (cst->state < 10) | |
375 | cst->state -= 3; | |
376 | else | |
377 | cst->state -= 6; | |
378 | } | |
379 | ||
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) { | |
383 | int offset; | |
384 | uint16_t *prob_len; | |
385 | int num_bits; | |
386 | int len; | |
387 | ||
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; | |
397 | } else { | |
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 | |
403 | + (cst->state << | |
404 | LZMA_NUM_POS_BITS_MAX) + | |
405 | pos_state); | |
406 | if (rc_is_bit_0(rc, prob)) { | |
407 | rc_update_bit_0(rc, prob); | |
408 | ||
409 | cst->state = cst->state < LZMA_NUM_LIT_STATES ? | |
410 | 9 : 11; | |
411 | copy_byte(wr, cst->rep0); | |
412 | return; | |
413 | } else { | |
414 | rc_update_bit_1(rc, prob); | |
415 | } | |
416 | } else { | |
417 | uint32_t distance; | |
418 | ||
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; | |
424 | } else { | |
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; | |
430 | } else { | |
431 | rc_update_bit_1(rc, prob); | |
432 | distance = cst->rep3; | |
433 | cst->rep3 = cst->rep2; | |
434 | } | |
435 | cst->rep2 = cst->rep1; | |
436 | } | |
437 | cst->rep1 = cst->rep0; | |
438 | cst->rep0 = distance; | |
439 | } | |
440 | cst->state = cst->state < LZMA_NUM_LIT_STATES ? 8 : 11; | |
441 | prob = p + LZMA_REP_LEN_CODER; | |
442 | } | |
443 | ||
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 | |
448 | + (pos_state << | |
449 | LZMA_LEN_NUM_LOW_BITS)); | |
450 | offset = 0; | |
451 | num_bits = LZMA_LEN_NUM_LOW_BITS; | |
452 | } else { | |
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 | |
458 | + (pos_state << | |
459 | LZMA_LEN_NUM_MID_BITS)); | |
460 | offset = 1 << LZMA_LEN_NUM_LOW_BITS; | |
461 | num_bits = LZMA_LEN_NUM_MID_BITS; | |
462 | } else { | |
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; | |
468 | } | |
469 | } | |
470 | ||
471 | rc_bit_tree_decode(rc, prob_len, num_bits, &len); | |
472 | len += offset; | |
473 | ||
474 | if (cst->state < 4) { | |
475 | int pos_slot; | |
476 | ||
477 | cst->state += LZMA_NUM_LIT_STATES; | |
478 | prob = | |
479 | p + LZMA_POS_SLOT + | |
480 | ((len < | |
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, | |
486 | &pos_slot); | |
487 | if (pos_slot >= LZMA_START_POS_MODEL_INDEX) { | |
488 | int i, mi; | |
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; | |
495 | } else { | |
496 | num_bits -= LZMA_NUM_ALIGN_BITS; | |
497 | while (num_bits--) | |
498 | cst->rep0 = (cst->rep0 << 1) | | |
499 | rc_direct_bit(rc); | |
500 | prob = p + LZMA_ALIGN; | |
501 | cst->rep0 <<= LZMA_NUM_ALIGN_BITS; | |
502 | num_bits = LZMA_NUM_ALIGN_BITS; | |
503 | } | |
504 | i = 1; | |
505 | mi = 1; | |
506 | while (num_bits--) { | |
507 | if (rc_get_bit(rc, prob + mi, &mi)) | |
508 | cst->rep0 |= i; | |
509 | i <<= 1; | |
510 | } | |
511 | } else | |
512 | cst->rep0 = pos_slot; | |
513 | if (++(cst->rep0) == 0) | |
514 | return; | |
515 | } | |
516 | ||
517 | len += LZMA_MATCH_MIN_LEN; | |
518 | ||
519 | copy_bytes(wr, cst->rep0, len); | |
520 | } | |
521 | ||
522 | ||
523 | ||
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, | |
528 | int *posp, | |
529 | void(*error_fn)(char *x) | |
530 | ) | |
531 | { | |
532 | struct lzma_header header; | |
533 | int lc, pb, lp; | |
534 | uint32_t pos_state_mask; | |
535 | uint32_t literal_pos_mask; | |
536 | uint16_t *p; | |
537 | int num_probs; | |
538 | struct rc rc; | |
539 | int i, mi; | |
540 | struct writer wr; | |
541 | struct cstate cst; | |
542 | unsigned char *inbuf; | |
543 | int ret = -1; | |
544 | ||
545 | set_error_fn(error_fn); | |
546 | if (!flush) | |
547 | in_len -= 4; /* Uncompressed size hack active in pre-boot | |
548 | environment */ | |
549 | if (buf) | |
550 | inbuf = buf; | |
551 | else | |
552 | inbuf = malloc(LZMA_IOBUF_SIZE); | |
553 | if (!inbuf) { | |
554 | error("Could not allocate input bufer"); | |
555 | goto exit_0; | |
556 | } | |
557 | ||
558 | cst.state = 0; | |
559 | cst.rep0 = cst.rep1 = cst.rep2 = cst.rep3 = 1; | |
560 | ||
561 | wr.header = &header; | |
562 | wr.flush = flush; | |
563 | wr.global_pos = 0; | |
564 | wr.previous_byte = 0; | |
565 | wr.buffer_pos = 0; | |
566 | ||
567 | rc_init(&rc, fill, inbuf, in_len); | |
568 | ||
569 | for (i = 0; i < sizeof(header); i++) { | |
570 | if (rc.ptr >= rc.buffer_end) | |
571 | rc_read(&rc); | |
572 | ((unsigned char *)&header)[i] = *rc.ptr++; | |
573 | } | |
574 | ||
575 | if (header.pos >= (9 * 5 * 5)) | |
576 | error("bad header"); | |
577 | ||
578 | mi = 0; | |
579 | lc = header.pos; | |
580 | while (lc >= 9) { | |
581 | mi++; | |
582 | lc -= 9; | |
583 | } | |
584 | pb = 0; | |
585 | lp = mi; | |
586 | while (lp >= 5) { | |
587 | pb++; | |
588 | lp -= 5; | |
589 | } | |
590 | pos_state_mask = (1 << pb) - 1; | |
591 | literal_pos_mask = (1 << lp) - 1; | |
592 | ||
593 | ENDIAN_CONVERT(header.dict_size); | |
594 | ENDIAN_CONVERT(header.dst_size); | |
595 | ||
596 | if (header.dict_size == 0) | |
597 | header.dict_size = 1; | |
598 | ||
599 | if (output) | |
600 | wr.buffer = output; | |
601 | else { | |
602 | wr.bufsize = MIN(header.dst_size, header.dict_size); | |
603 | wr.buffer = large_malloc(wr.bufsize); | |
604 | } | |
605 | if (wr.buffer == NULL) | |
606 | goto exit_1; | |
607 | ||
608 | num_probs = LZMA_BASE_SIZE + (LZMA_LIT_SIZE << (lc + lp)); | |
609 | p = (uint16_t *) large_malloc(num_probs * sizeof(*p)); | |
610 | if (p == 0) | |
611 | goto exit_2; | |
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; | |
615 | ||
616 | rc_init_code(&rc); | |
617 | ||
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); | |
625 | else { | |
626 | process_bit1(&wr, &rc, &cst, p, pos_state, prob); | |
627 | if (cst.rep0 == 0) | |
628 | break; | |
629 | } | |
630 | } | |
631 | ||
632 | if (posp) | |
633 | *posp = rc.ptr-rc.buffer; | |
634 | if (wr.flush) | |
635 | wr.flush(wr.buffer, wr.buffer_pos); | |
636 | ret = 0; | |
637 | large_free(p); | |
638 | exit_2: | |
639 | if (!output) | |
640 | large_free(wr.buffer); | |
641 | exit_1: | |
642 | if (!buf) | |
643 | free(inbuf); | |
644 | exit_0: | |
645 | return ret; | |
646 | } | |
647 | ||
648 | #define decompress unlzma |