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