lib/decompress_unlzma.c

   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 #ifdef STATIC
  33 #define PREBOOT
  34 #else
  35 #include <linux/decompress/unlzma.h>
  36 #include <linux/slab.h>
  37 #endif /* STATIC */
  38
  39 #include <linux/decompress/mm.h>
  40
  41 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
  42
  43 static long long INIT read_int(unsigned char *ptr, int size)
  44 {
  45         int i;
  46         long long ret = 0;
  47
  48         for (i = 0; i < size; i++)
  49                 ret = (ret << 8) | ptr[size-i-1];
  50         return ret;
  51 }
  52
  53 #define ENDIAN_CONVERT(x) \
  54   x = (typeof(x))read_int((unsigned char *)&x, sizeof(x))
  55
  56
  57 /* Small range coder implementation for lzma.
  58  *Copyright (C) 2006  Aurelien Jacobs < aurel@gnuage.org >
  59  *
  60  *Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
  61  *Copyright (c) 1999-2005  Igor Pavlov
  62  */
  63
  64 #include <linux/compiler.h>
  65
  66 #define LZMA_IOBUF_SIZE 0x10000
  67
  68 struct rc {
  69         int (*fill)(void*, unsigned int);
  70         uint8_t *ptr;
  71         uint8_t *buffer;
  72         uint8_t *buffer_end;
  73         int buffer_size;
  74         uint32_t code;
  75         uint32_t range;
  76         uint32_t bound;
  77         void (*error)(char *);
  78 };
  79
  80
  81 #define RC_TOP_BITS 24
  82 #define RC_MOVE_BITS 5
  83 #define RC_MODEL_TOTAL_BITS 11
  84
  85
  86 static int INIT nofill(void *buffer, unsigned int len)
  87 {
  88         return -1;
  89 }
  90
  91 /* Called twice: once at startup and once in rc_normalize() */
  92 static void INIT rc_read(struct rc *rc)
  93 {
  94         rc->buffer_size = rc->fill((char *)rc->buffer, LZMA_IOBUF_SIZE);
  95         if (rc->buffer_size <= 0)
  96                 rc->error("unexpected EOF");
  97         rc->ptr = rc->buffer;
  98         rc->buffer_end = rc->buffer + rc->buffer_size;
  99 }
 100
 101 /* Called once */
 102 static inline void INIT rc_init(struct rc *rc,
 103                                        int (*fill)(void*, unsigned int),
 104                                        char *buffer, int buffer_size)
 105 {
 106         if (fill)
 107                 rc->fill = fill;
 108         else
 109                 rc->fill = nofill;
 110         rc->buffer = (uint8_t *)buffer;
 111         rc->buffer_size = buffer_size;
 112         rc->buffer_end = rc->buffer + rc->buffer_size;
 113         rc->ptr = rc->buffer;
 114
 115         rc->code = 0;
 116         rc->range = 0xFFFFFFFF;
 117 }
 118
 119 static inline void INIT rc_init_code(struct rc *rc)
 120 {
 121         int i;
 122
 123         for (i = 0; i < 5; i++) {
 124                 if (rc->ptr >= rc->buffer_end)
 125                         rc_read(rc);
 126                 rc->code = (rc->code << 8) | *rc->ptr++;
 127         }
 128 }
 129
 130
 131 /* Called once. TODO: bb_maybe_free() */
 132 static inline void INIT rc_free(struct rc *rc)
 133 {
 134         free(rc->buffer);
 135 }
 136
 137 /* Called twice, but one callsite is in inline'd rc_is_bit_0_helper() */
 138 static void INIT rc_do_normalize(struct rc *rc)
 139 {
 140         if (rc->ptr >= rc->buffer_end)
 141                 rc_read(rc);
 142         rc->range <<= 8;
 143         rc->code = (rc->code << 8) | *rc->ptr++;
 144 }
 145 static inline void INIT rc_normalize(struct rc *rc)
 146 {
 147         if (rc->range < (1 << RC_TOP_BITS))
 148                 rc_do_normalize(rc);
 149 }
 150
 151 /* Called 9 times */
 152 /* Why rc_is_bit_0_helper exists?
 153  *Because we want to always expose (rc->code < rc->bound) to optimizer
 154  */
 155 static inline uint32_t INIT rc_is_bit_0_helper(struct rc *rc, uint16_t *p)
 156 {
 157         rc_normalize(rc);
 158         rc->bound = *p * (rc->range >> RC_MODEL_TOTAL_BITS);
 159         return rc->bound;
 160 }
 161 static inline int INIT rc_is_bit_0(struct rc *rc, uint16_t *p)
 162 {
 163         uint32_t t = rc_is_bit_0_helper(rc, p);
 164         return rc->code < t;
 165 }
 166
 167 /* Called ~10 times, but very small, thus inlined */
 168 static inline void INIT rc_update_bit_0(struct rc *rc, uint16_t *p)
 169 {
 170         rc->range = rc->bound;
 171         *p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS;
 172 }
 173 static inline void INIT rc_update_bit_1(struct rc *rc, uint16_t *p)
 174 {
 175         rc->range -= rc->bound;
 176         rc->code -= rc->bound;
 177         *p -= *p >> RC_MOVE_BITS;
 178 }
 179
 180 /* Called 4 times in unlzma loop */
 181 static int INIT rc_get_bit(struct rc *rc, uint16_t *p, int *symbol)
 182 {
 183         if (rc_is_bit_0(rc, p)) {
 184                 rc_update_bit_0(rc, p);
 185                 *symbol *= 2;
 186                 return 0;
 187         } else {
 188                 rc_update_bit_1(rc, p);
 189                 *symbol = *symbol * 2 + 1;
 190                 return 1;
 191         }
 192 }
 193
 194 /* Called once */
 195 static inline int INIT rc_direct_bit(struct rc *rc)
 196 {
 197         rc_normalize(rc);
 198         rc->range >>= 1;
 199         if (rc->code >= rc->range) {
 200                 rc->code -= rc->range;
 201                 return 1;
 202         }
 203         return 0;
 204 }
 205
 206 /* Called twice */
 207 static inline void INIT
 208 rc_bit_tree_decode(struct rc *rc, uint16_t *p, int num_levels, int *symbol)
 209 {
 210         int i = num_levels;
 211
 212         *symbol = 1;
 213         while (i--)
 214                 rc_get_bit(rc, p + *symbol, symbol);
 215         *symbol -= 1 << num_levels;
 216 }
 217
 218
 219 /*
 220  * Small lzma deflate implementation.
 221  * Copyright (C) 2006  Aurelien Jacobs < aurel@gnuage.org >
 222  *
 223  * Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
 224  * Copyright (C) 1999-2005  Igor Pavlov
 225  */
 226
 227
 228 struct lzma_header {
 229         uint8_t pos;
 230         uint32_t dict_size;
 231         uint64_t dst_size;
 232 } __attribute__ ((packed)) ;
 233
 234
 235 #define LZMA_BASE_SIZE 1846
 236 #define LZMA_LIT_SIZE 768
 237
 238 #define LZMA_NUM_POS_BITS_MAX 4
 239
 240 #define LZMA_LEN_NUM_LOW_BITS 3
 241 #define LZMA_LEN_NUM_MID_BITS 3
 242 #define LZMA_LEN_NUM_HIGH_BITS 8
 243
 244 #define LZMA_LEN_CHOICE 0
 245 #define LZMA_LEN_CHOICE_2 (LZMA_LEN_CHOICE + 1)
 246 #define LZMA_LEN_LOW (LZMA_LEN_CHOICE_2 + 1)
 247 #define LZMA_LEN_MID (LZMA_LEN_LOW \
 248                       + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS)))
 249 #define LZMA_LEN_HIGH (LZMA_LEN_MID \
 250                        +(1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS)))
 251 #define LZMA_NUM_LEN_PROBS (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS))
 252
 253 #define LZMA_NUM_STATES 12
 254 #define LZMA_NUM_LIT_STATES 7
 255
 256 #define LZMA_START_POS_MODEL_INDEX 4
 257 #define LZMA_END_POS_MODEL_INDEX 14
 258 #define LZMA_NUM_FULL_DISTANCES (1 << (LZMA_END_POS_MODEL_INDEX >> 1))
 259
 260 #define LZMA_NUM_POS_SLOT_BITS 6
 261 #define LZMA_NUM_LEN_TO_POS_STATES 4
 262
 263 #define LZMA_NUM_ALIGN_BITS 4
 264
 265 #define LZMA_MATCH_MIN_LEN 2
 266
 267 #define LZMA_IS_MATCH 0
 268 #define LZMA_IS_REP (LZMA_IS_MATCH + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX))
 269 #define LZMA_IS_REP_G0 (LZMA_IS_REP + LZMA_NUM_STATES)
 270 #define LZMA_IS_REP_G1 (LZMA_IS_REP_G0 + LZMA_NUM_STATES)
 271 #define LZMA_IS_REP_G2 (LZMA_IS_REP_G1 + LZMA_NUM_STATES)
 272 #define LZMA_IS_REP_0_LONG (LZMA_IS_REP_G2 + LZMA_NUM_STATES)
 273 #define LZMA_POS_SLOT (LZMA_IS_REP_0_LONG \
 274                        + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX))
 275 #define LZMA_SPEC_POS (LZMA_POS_SLOT \
 276                        +(LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS))
 277 #define LZMA_ALIGN (LZMA_SPEC_POS \
 278                     + LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX)
 279 #define LZMA_LEN_CODER (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS))
 280 #define LZMA_REP_LEN_CODER (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS)
 281 #define LZMA_LITERAL (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS)
 282
 283
 284 struct writer {
 285         uint8_t *buffer;
 286         uint8_t previous_byte;
 287         size_t buffer_pos;
 288         int bufsize;
 289         size_t global_pos;
 290         int(*flush)(void*, unsigned int);
 291         struct lzma_header *header;
 292 };
 293
 294 struct cstate {
 295         int state;
 296         uint32_t rep0, rep1, rep2, rep3;
 297 };
 298
 299 static inline size_t INIT get_pos(struct writer *wr)
 300 {
 301         return
 302                 wr->global_pos + wr->buffer_pos;
 303 }
 304
 305 static inline uint8_t INIT peek_old_byte(struct writer *wr,
 306                                                 uint32_t offs)
 307 {
 308         if (!wr->flush) {
 309                 int32_t pos;
 310                 while (offs > wr->header->dict_size)
 311                         offs -= wr->header->dict_size;
 312                 pos = wr->buffer_pos - offs;
 313                 return wr->buffer[pos];
 314         } else {
 315                 uint32_t pos = wr->buffer_pos - offs;
 316                 while (pos >= wr->header->dict_size)
 317                         pos += wr->header->dict_size;
 318                 return wr->buffer[pos];
 319         }
 320
 321 }
 322
 323 static inline void INIT write_byte(struct writer *wr, uint8_t byte)
 324 {
 325         wr->buffer[wr->buffer_pos++] = wr->previous_byte = byte;
 326         if (wr->flush && wr->buffer_pos == wr->header->dict_size) {
 327                 wr->buffer_pos = 0;
 328                 wr->global_pos += wr->header->dict_size;
 329                 wr->flush((char *)wr->buffer, wr->header->dict_size);
 330         }
 331 }
 332
 333
 334 static inline void INIT copy_byte(struct writer *wr, uint32_t offs)
 335 {
 336         write_byte(wr, peek_old_byte(wr, offs));
 337 }
 338
 339 static inline void INIT copy_bytes(struct writer *wr,
 340                                          uint32_t rep0, int len)
 341 {
 342         do {
 343                 copy_byte(wr, rep0);
 344                 len--;
 345         } while (len != 0 && wr->buffer_pos < wr->header->dst_size);
 346 }
 347
 348 static inline void INIT process_bit0(struct writer *wr, struct rc *rc,
 349                                      struct cstate *cst, uint16_t *p,
 350                                      int pos_state, uint16_t *prob,
 351                                      int lc, uint32_t literal_pos_mask) {
 352         int mi = 1;
 353         rc_update_bit_0(rc, prob);
 354         prob = (p + LZMA_LITERAL +
 355                 (LZMA_LIT_SIZE
 356                  * (((get_pos(wr) & literal_pos_mask) << lc)
 357                     + (wr->previous_byte >> (8 - lc))))
 358                 );
 359
 360         if (cst->state >= LZMA_NUM_LIT_STATES) {
 361                 int match_byte = peek_old_byte(wr, cst->rep0);
 362                 do {
 363                         int bit;
 364                         uint16_t *prob_lit;
 365
 366                         match_byte <<= 1;
 367                         bit = match_byte & 0x100;
 368                         prob_lit = prob + 0x100 + bit + mi;
 369                         if (rc_get_bit(rc, prob_lit, &mi)) {
 370                                 if (!bit)
 371                                         break;
 372                         } else {
 373                                 if (bit)
 374                                         break;
 375                         }
 376                 } while (mi < 0x100);
 377         }
 378         while (mi < 0x100) {
 379                 uint16_t *prob_lit = prob + mi;
 380                 rc_get_bit(rc, prob_lit, &mi);
 381         }
 382         write_byte(wr, mi);
 383         if (cst->state < 4)
 384                 cst->state = 0;
 385         else if (cst->state < 10)
 386                 cst->state -= 3;
 387         else
 388                 cst->state -= 6;
 389 }
 390
 391 static inline void INIT process_bit1(struct writer *wr, struct rc *rc,
 392                                             struct cstate *cst, uint16_t *p,
 393                                             int pos_state, uint16_t *prob) {
 394   int offset;
 395         uint16_t *prob_len;
 396         int num_bits;
 397         int len;
 398
 399         rc_update_bit_1(rc, prob);
 400         prob = p + LZMA_IS_REP + cst->state;
 401         if (rc_is_bit_0(rc, prob)) {
 402                 rc_update_bit_0(rc, prob);
 403                 cst->rep3 = cst->rep2;
 404                 cst->rep2 = cst->rep1;
 405                 cst->rep1 = cst->rep0;
 406                 cst->state = cst->state < LZMA_NUM_LIT_STATES ? 0 : 3;
 407                 prob = p + LZMA_LEN_CODER;
 408         } else {
 409                 rc_update_bit_1(rc, prob);
 410                 prob = p + LZMA_IS_REP_G0 + cst->state;
 411                 if (rc_is_bit_0(rc, prob)) {
 412                         rc_update_bit_0(rc, prob);
 413                         prob = (p + LZMA_IS_REP_0_LONG
 414                                 + (cst->state <<
 415                                    LZMA_NUM_POS_BITS_MAX) +
 416                                 pos_state);
 417                         if (rc_is_bit_0(rc, prob)) {
 418                                 rc_update_bit_0(rc, prob);
 419
 420                                 cst->state = cst->state < LZMA_NUM_LIT_STATES ?
 421                                         9 : 11;
 422                                 copy_byte(wr, cst->rep0);
 423                                 return;
 424                         } else {
 425                                 rc_update_bit_1(rc, prob);
 426                         }
 427                 } else {
 428                         uint32_t distance;
 429
 430                         rc_update_bit_1(rc, prob);
 431                         prob = p + LZMA_IS_REP_G1 + cst->state;
 432                         if (rc_is_bit_0(rc, prob)) {
 433                                 rc_update_bit_0(rc, prob);
 434                                 distance = cst->rep1;
 435                         } else {
 436                                 rc_update_bit_1(rc, prob);
 437                                 prob = p + LZMA_IS_REP_G2 + cst->state;
 438                                 if (rc_is_bit_0(rc, prob)) {
 439                                         rc_update_bit_0(rc, prob);
 440                                         distance = cst->rep2;
 441                                 } else {
 442                                         rc_update_bit_1(rc, prob);
 443                                         distance = cst->rep3;
 444                                         cst->rep3 = cst->rep2;
 445                                 }
 446                                 cst->rep2 = cst->rep1;
 447                         }
 448                         cst->rep1 = cst->rep0;
 449                         cst->rep0 = distance;
 450                 }
 451                 cst->state = cst->state < LZMA_NUM_LIT_STATES ? 8 : 11;
 452                 prob = p + LZMA_REP_LEN_CODER;
 453         }
 454
 455         prob_len = prob + LZMA_LEN_CHOICE;
 456         if (rc_is_bit_0(rc, prob_len)) {
 457                 rc_update_bit_0(rc, prob_len);
 458                 prob_len = (prob + LZMA_LEN_LOW
 459                             + (pos_state <<
 460                                LZMA_LEN_NUM_LOW_BITS));
 461                 offset = 0;
 462                 num_bits = LZMA_LEN_NUM_LOW_BITS;
 463         } else {
 464                 rc_update_bit_1(rc, prob_len);
 465                 prob_len = prob + LZMA_LEN_CHOICE_2;
 466                 if (rc_is_bit_0(rc, prob_len)) {
 467                         rc_update_bit_0(rc, prob_len);
 468                         prob_len = (prob + LZMA_LEN_MID
 469                                     + (pos_state <<
 470                                        LZMA_LEN_NUM_MID_BITS));
 471                         offset = 1 << LZMA_LEN_NUM_LOW_BITS;
 472                         num_bits = LZMA_LEN_NUM_MID_BITS;
 473                 } else {
 474                         rc_update_bit_1(rc, prob_len);
 475                         prob_len = prob + LZMA_LEN_HIGH;
 476                         offset = ((1 << LZMA_LEN_NUM_LOW_BITS)
 477                                   + (1 << LZMA_LEN_NUM_MID_BITS));
 478                         num_bits = LZMA_LEN_NUM_HIGH_BITS;
 479                 }
 480         }
 481
 482         rc_bit_tree_decode(rc, prob_len, num_bits, &len);
 483         len += offset;
 484
 485         if (cst->state < 4) {
 486                 int pos_slot;
 487
 488                 cst->state += LZMA_NUM_LIT_STATES;
 489                 prob =
 490                         p + LZMA_POS_SLOT +
 491                         ((len <
 492                           LZMA_NUM_LEN_TO_POS_STATES ? len :
 493                           LZMA_NUM_LEN_TO_POS_STATES - 1)
 494                          << LZMA_NUM_POS_SLOT_BITS);
 495                 rc_bit_tree_decode(rc, prob,
 496                                    LZMA_NUM_POS_SLOT_BITS,
 497                                    &pos_slot);
 498                 if (pos_slot >= LZMA_START_POS_MODEL_INDEX) {
 499                         int i, mi;
 500                         num_bits = (pos_slot >> 1) - 1;
 501                         cst->rep0 = 2 | (pos_slot & 1);
 502                         if (pos_slot < LZMA_END_POS_MODEL_INDEX) {
 503                                 cst->rep0 <<= num_bits;
 504                                 prob = p + LZMA_SPEC_POS +
 505                                         cst->rep0 - pos_slot - 1;
 506                         } else {
 507                                 num_bits -= LZMA_NUM_ALIGN_BITS;
 508                                 while (num_bits--)
 509                                         cst->rep0 = (cst->rep0 << 1) |
 510                                                 rc_direct_bit(rc);
 511                                 prob = p + LZMA_ALIGN;
 512                                 cst->rep0 <<= LZMA_NUM_ALIGN_BITS;
 513                                 num_bits = LZMA_NUM_ALIGN_BITS;
 514                         }
 515                         i = 1;
 516                         mi = 1;
 517                         while (num_bits--) {
 518                                 if (rc_get_bit(rc, prob + mi, &mi))
 519                                         cst->rep0 |= i;
 520                                 i <<= 1;
 521                         }
 522                 } else
 523                         cst->rep0 = pos_slot;
 524                 if (++(cst->rep0) == 0)
 525                         return;
 526         }
 527
 528         len += LZMA_MATCH_MIN_LEN;
 529
 530         copy_bytes(wr, cst->rep0, len);
 531 }
 532
 533
 534
 535 STATIC inline int INIT unlzma(unsigned char *buf, int in_len,
 536                               int(*fill)(void*, unsigned int),
 537                               int(*flush)(void*, unsigned int),
 538                               unsigned char *output,
 539                               int *posp,
 540                               void(*error)(char *x)
 541         )
 542 {
 543         struct lzma_header header;
 544         int lc, pb, lp;
 545         uint32_t pos_state_mask;
 546         uint32_t literal_pos_mask;
 547         uint16_t *p;
 548         int num_probs;
 549         struct rc rc;
 550         int i, mi;
 551         struct writer wr;
 552         struct cstate cst;
 553         unsigned char *inbuf;
 554         int ret = -1;
 555
 556         rc.error = error;
 557
 558         if (buf)
 559                 inbuf = buf;
 560         else
 561                 inbuf = malloc(LZMA_IOBUF_SIZE);
 562         if (!inbuf) {
 563                 error("Could not allocate input bufer");
 564                 goto exit_0;
 565         }
 566
 567         cst.state = 0;
 568         cst.rep0 = cst.rep1 = cst.rep2 = cst.rep3 = 1;
 569
 570         wr.header = &header;
 571         wr.flush = flush;
 572         wr.global_pos = 0;
 573         wr.previous_byte = 0;
 574         wr.buffer_pos = 0;
 575
 576         rc_init(&rc, fill, inbuf, in_len);
 577
 578         for (i = 0; i < sizeof(header); i++) {
 579                 if (rc.ptr >= rc.buffer_end)
 580                         rc_read(&rc);
 581                 ((unsigned char *)&header)[i] = *rc.ptr++;
 582         }
 583
 584         if (header.pos >= (9 * 5 * 5))
 585                 error("bad header");
 586
 587         mi = 0;
 588         lc = header.pos;
 589         while (lc >= 9) {
 590                 mi++;
 591                 lc -= 9;
 592         }
 593         pb = 0;
 594         lp = mi;
 595         while (lp >= 5) {
 596                 pb++;
 597                 lp -= 5;
 598         }
 599         pos_state_mask = (1 << pb) - 1;
 600         literal_pos_mask = (1 << lp) - 1;
 601
 602         ENDIAN_CONVERT(header.dict_size);
 603         ENDIAN_CONVERT(header.dst_size);
 604
 605         if (header.dict_size == 0)
 606                 header.dict_size = 1;
 607
 608         if (output)
 609                 wr.buffer = output;
 610         else {
 611                 wr.bufsize = MIN(header.dst_size, header.dict_size);
 612                 wr.buffer = large_malloc(wr.bufsize);
 613         }
 614         if (wr.buffer == NULL)
 615                 goto exit_1;
 616
 617         num_probs = LZMA_BASE_SIZE + (LZMA_LIT_SIZE << (lc + lp));
 618         p = (uint16_t *) large_malloc(num_probs * sizeof(*p));
 619         if (p == 0)
 620                 goto exit_2;
 621         num_probs = LZMA_LITERAL + (LZMA_LIT_SIZE << (lc + lp));
 622         for (i = 0; i < num_probs; i++)
 623                 p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1;
 624
 625         rc_init_code(&rc);
 626
 627         while (get_pos(&wr) < header.dst_size) {
 628                 int pos_state = get_pos(&wr) & pos_state_mask;
 629                 uint16_t *prob = p + LZMA_IS_MATCH +
 630                         (cst.state << LZMA_NUM_POS_BITS_MAX) + pos_state;
 631                 if (rc_is_bit_0(&rc, prob))
 632                         process_bit0(&wr, &rc, &cst, p, pos_state, prob,
 633                                      lc, literal_pos_mask);
 634                 else {
 635                         process_bit1(&wr, &rc, &cst, p, pos_state, prob);
 636                         if (cst.rep0 == 0)
 637                                 break;
 638                 }
 639         }
 640
 641         if (posp)
 642                 *posp = rc.ptr-rc.buffer;
 643         if (wr.flush)
 644                 wr.flush(wr.buffer, wr.buffer_pos);
 645         ret = 0;
 646         large_free(p);
 647 exit_2:
 648         if (!output)
 649                 large_free(wr.buffer);
 650 exit_1:
 651         if (!buf)
 652                 free(inbuf);
 653 exit_0:
 654         return ret;
 655 }
 656
 657 #ifdef PREBOOT
 658 STATIC int INIT decompress(unsigned char *buf, int in_len,
 659                               int(*fill)(void*, unsigned int),
 660                               int(*flush)(void*, unsigned int),
 661                               unsigned char *output,
 662                               int *posp,
 663                               void(*error)(char *x)
 664         )
 665 {
 666         return unlzma(buf, in_len - 4, fill, flush, output, posp, error);
 667 }
 668 #endif