the-tree/lib/decompress_unlzma.c

0001 /* Lzma decompressor for Linux kernel. Shamelessly snarfed
0002  *from busybox 1.1.1
0003  *
0004  *Linux kernel adaptation
0005  *Copyright (C) 2006  Alain < alain@knaff.lu >
0006  *
0007  *Based on small lzma deflate implementation/Small range coder
0008  *implementation for lzma.
0009  *Copyright (C) 2006  Aurelien Jacobs < aurel@gnuage.org >
0010  *
0011  *Based on LzmaDecode.c from the LZMA SDK 4.22 (https://www.7-zip.org/)
0012  *Copyright (C) 1999-2005  Igor Pavlov
0013  *
0014  *Copyrights of the parts, see headers below.
0015  *
0016  *
0017  *This program is free software; you can redistribute it and/or
0018  *modify it under the terms of the GNU Lesser General Public
0019  *License as published by the Free Software Foundation; either
0020  *version 2.1 of the License, or (at your option) any later version.
0021  *
0022  *This program is distributed in the hope that it will be useful,
0023  *but WITHOUT ANY WARRANTY; without even the implied warranty of
0024  *MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
0025  *Lesser General Public License for more details.
0026  *
0027  *You should have received a copy of the GNU Lesser General Public
0028  *License along with this library; if not, write to the Free Software
0029  *Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
0030  */
0031
0032 #ifdef STATIC
0033 #define PREBOOT
0034 #else
0035 #include <linux/decompress/unlzma.h>
0036 #endif /* STATIC */
0037
0038 #include <linux/decompress/mm.h>
0039
0040 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
0041
0042 static long long INIT read_int(unsigned char *ptr, int size)
0043 {
0044     int i;
0045     long long ret = 0;
0046
0047     for (i = 0; i < size; i++)
0048         ret = (ret << 8) | ptr[size-i-1];
0049     return ret;
0050 }
0051
0052 #define ENDIAN_CONVERT(x) \
0053   x = (typeof(x))read_int((unsigned char *)&x, sizeof(x))
0054
0055
0056 /* Small range coder implementation for lzma.
0057  *Copyright (C) 2006  Aurelien Jacobs < aurel@gnuage.org >
0058  *
0059  *Based on LzmaDecode.c from the LZMA SDK 4.22 (https://www.7-zip.org/)
0060  *Copyright (c) 1999-2005  Igor Pavlov
0061  */
0062
0063 #include <linux/compiler.h>
0064
0065 #define LZMA_IOBUF_SIZE 0x10000
0066
0067 struct rc {
0068     long (*fill)(void*, unsigned long);
0069     uint8_t *ptr;
0070     uint8_t *buffer;
0071     uint8_t *buffer_end;
0072     long buffer_size;
0073     uint32_t code;
0074     uint32_t range;
0075     uint32_t bound;
0076     void (*error)(char *);
0077 };
0078
0079
0080 #define RC_TOP_BITS 24
0081 #define RC_MOVE_BITS 5
0082 #define RC_MODEL_TOTAL_BITS 11
0083
0084
0085 static long INIT nofill(void *buffer, unsigned long len)
0086 {
0087     return -1;
0088 }
0089
0090 /* Called twice: once at startup and once in rc_normalize() */
0091 static void INIT rc_read(struct rc *rc)
0092 {
0093     rc->buffer_size = rc->fill((char *)rc->buffer, LZMA_IOBUF_SIZE);
0094     if (rc->buffer_size <= 0)
0095         rc->error("unexpected EOF");
0096     rc->ptr = rc->buffer;
0097     rc->buffer_end = rc->buffer + rc->buffer_size;
0098 }
0099
0100 /* Called once */
0101 static inline void INIT rc_init(struct rc *rc,
0102                        long (*fill)(void*, unsigned long),
0103                        char *buffer, long buffer_size)
0104 {
0105     if (fill)
0106         rc->fill = fill;
0107     else
0108         rc->fill = nofill;
0109     rc->buffer = (uint8_t *)buffer;
0110     rc->buffer_size = buffer_size;
0111     rc->buffer_end = rc->buffer + rc->buffer_size;
0112     rc->ptr = rc->buffer;
0113
0114     rc->code = 0;
0115     rc->range = 0xFFFFFFFF;
0116 }
0117
0118 static inline void INIT rc_init_code(struct rc *rc)
0119 {
0120     int i;
0121
0122     for (i = 0; i < 5; i++) {
0123         if (rc->ptr >= rc->buffer_end)
0124             rc_read(rc);
0125         rc->code = (rc->code << 8) | *rc->ptr++;
0126     }
0127 }
0128
0129
0130 /* Called twice, but one callsite is in inline'd rc_is_bit_0_helper() */
0131 static void INIT rc_do_normalize(struct rc *rc)
0132 {
0133     if (rc->ptr >= rc->buffer_end)
0134         rc_read(rc);
0135     rc->range <<= 8;
0136     rc->code = (rc->code << 8) | *rc->ptr++;
0137 }
0138 static inline void INIT rc_normalize(struct rc *rc)
0139 {
0140     if (rc->range < (1 << RC_TOP_BITS))
0141         rc_do_normalize(rc);
0142 }
0143
0144 /* Called 9 times */
0145 /* Why rc_is_bit_0_helper exists?
0146  *Because we want to always expose (rc->code < rc->bound) to optimizer
0147  */
0148 static inline uint32_t INIT rc_is_bit_0_helper(struct rc *rc, uint16_t *p)
0149 {
0150     rc_normalize(rc);
0151     rc->bound = *p * (rc->range >> RC_MODEL_TOTAL_BITS);
0152     return rc->bound;
0153 }
0154 static inline int INIT rc_is_bit_0(struct rc *rc, uint16_t *p)
0155 {
0156     uint32_t t = rc_is_bit_0_helper(rc, p);
0157     return rc->code < t;
0158 }
0159
0160 /* Called ~10 times, but very small, thus inlined */
0161 static inline void INIT rc_update_bit_0(struct rc *rc, uint16_t *p)
0162 {
0163     rc->range = rc->bound;
0164     *p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS;
0165 }
0166 static inline void INIT rc_update_bit_1(struct rc *rc, uint16_t *p)
0167 {
0168     rc->range -= rc->bound;
0169     rc->code -= rc->bound;
0170     *p -= *p >> RC_MOVE_BITS;
0171 }
0172
0173 /* Called 4 times in unlzma loop */
0174 static int INIT rc_get_bit(struct rc *rc, uint16_t *p, int *symbol)
0175 {
0176     if (rc_is_bit_0(rc, p)) {
0177         rc_update_bit_0(rc, p);
0178         *symbol *= 2;
0179         return 0;
0180     } else {
0181         rc_update_bit_1(rc, p);
0182         *symbol = *symbol * 2 + 1;
0183         return 1;
0184     }
0185 }
0186
0187 /* Called once */
0188 static inline int INIT rc_direct_bit(struct rc *rc)
0189 {
0190     rc_normalize(rc);
0191     rc->range >>= 1;
0192     if (rc->code >= rc->range) {
0193         rc->code -= rc->range;
0194         return 1;
0195     }
0196     return 0;
0197 }
0198
0199 /* Called twice */
0200 static inline void INIT
0201 rc_bit_tree_decode(struct rc *rc, uint16_t *p, int num_levels, int *symbol)
0202 {
0203     int i = num_levels;
0204
0205     *symbol = 1;
0206     while (i--)
0207         rc_get_bit(rc, p + *symbol, symbol);
0208     *symbol -= 1 << num_levels;
0209 }
0210
0211
0212 /*
0213  * Small lzma deflate implementation.
0214  * Copyright (C) 2006  Aurelien Jacobs < aurel@gnuage.org >
0215  *
0216  * Based on LzmaDecode.c from the LZMA SDK 4.22 (https://www.7-zip.org/)
0217  * Copyright (C) 1999-2005  Igor Pavlov
0218  */
0219
0220
0221 struct lzma_header {
0222     uint8_t pos;
0223     uint32_t dict_size;
0224     uint64_t dst_size;
0225 } __attribute__ ((packed)) ;
0226
0227
0228 #define LZMA_BASE_SIZE 1846
0229 #define LZMA_LIT_SIZE 768
0230
0231 #define LZMA_NUM_POS_BITS_MAX 4
0232
0233 #define LZMA_LEN_NUM_LOW_BITS 3
0234 #define LZMA_LEN_NUM_MID_BITS 3
0235 #define LZMA_LEN_NUM_HIGH_BITS 8
0236
0237 #define LZMA_LEN_CHOICE 0
0238 #define LZMA_LEN_CHOICE_2 (LZMA_LEN_CHOICE + 1)
0239 #define LZMA_LEN_LOW (LZMA_LEN_CHOICE_2 + 1)
0240 #define LZMA_LEN_MID (LZMA_LEN_LOW \
0241               + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS)))
0242 #define LZMA_LEN_HIGH (LZMA_LEN_MID \
0243                +(1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS)))
0244 #define LZMA_NUM_LEN_PROBS (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS))
0245
0246 #define LZMA_NUM_STATES 12
0247 #define LZMA_NUM_LIT_STATES 7
0248
0249 #define LZMA_START_POS_MODEL_INDEX 4
0250 #define LZMA_END_POS_MODEL_INDEX 14
0251 #define LZMA_NUM_FULL_DISTANCES (1 << (LZMA_END_POS_MODEL_INDEX >> 1))
0252
0253 #define LZMA_NUM_POS_SLOT_BITS 6
0254 #define LZMA_NUM_LEN_TO_POS_STATES 4
0255
0256 #define LZMA_NUM_ALIGN_BITS 4
0257
0258 #define LZMA_MATCH_MIN_LEN 2
0259
0260 #define LZMA_IS_MATCH 0
0261 #define LZMA_IS_REP (LZMA_IS_MATCH + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX))
0262 #define LZMA_IS_REP_G0 (LZMA_IS_REP + LZMA_NUM_STATES)
0263 #define LZMA_IS_REP_G1 (LZMA_IS_REP_G0 + LZMA_NUM_STATES)
0264 #define LZMA_IS_REP_G2 (LZMA_IS_REP_G1 + LZMA_NUM_STATES)
0265 #define LZMA_IS_REP_0_LONG (LZMA_IS_REP_G2 + LZMA_NUM_STATES)
0266 #define LZMA_POS_SLOT (LZMA_IS_REP_0_LONG \
0267                + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX))
0268 #define LZMA_SPEC_POS (LZMA_POS_SLOT \
0269                +(LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS))
0270 #define LZMA_ALIGN (LZMA_SPEC_POS \
0271             + LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX)
0272 #define LZMA_LEN_CODER (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS))
0273 #define LZMA_REP_LEN_CODER (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS)
0274 #define LZMA_LITERAL (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS)
0275
0276
0277 struct writer {
0278     uint8_t *buffer;
0279     uint8_t previous_byte;
0280     size_t buffer_pos;
0281     int bufsize;
0282     size_t global_pos;
0283     long (*flush)(void*, unsigned long);
0284     struct lzma_header *header;
0285 };
0286
0287 struct cstate {
0288     int state;
0289     uint32_t rep0, rep1, rep2, rep3;
0290 };
0291
0292 static inline size_t INIT get_pos(struct writer *wr)
0293 {
0294     return
0295         wr->global_pos + wr->buffer_pos;
0296 }
0297
0298 static inline uint8_t INIT peek_old_byte(struct writer *wr,
0299                         uint32_t offs)
0300 {
0301     if (!wr->flush) {
0302         int32_t pos;
0303         while (offs > wr->header->dict_size)
0304             offs -= wr->header->dict_size;
0305         pos = wr->buffer_pos - offs;
0306         return wr->buffer[pos];
0307     } else {
0308         uint32_t pos = wr->buffer_pos - offs;
0309         while (pos >= wr->header->dict_size)
0310             pos += wr->header->dict_size;
0311         return wr->buffer[pos];
0312     }
0313
0314 }
0315
0316 static inline int INIT write_byte(struct writer *wr, uint8_t byte)
0317 {
0318     wr->buffer[wr->buffer_pos++] = wr->previous_byte = byte;
0319     if (wr->flush && wr->buffer_pos == wr->header->dict_size) {
0320         wr->buffer_pos = 0;
0321         wr->global_pos += wr->header->dict_size;
0322         if (wr->flush((char *)wr->buffer, wr->header->dict_size)
0323                 != wr->header->dict_size)
0324             return -1;
0325     }
0326     return 0;
0327 }
0328
0329
0330 static inline int INIT copy_byte(struct writer *wr, uint32_t offs)
0331 {
0332     return write_byte(wr, peek_old_byte(wr, offs));
0333 }
0334
0335 static inline int INIT copy_bytes(struct writer *wr,
0336                      uint32_t rep0, int len)
0337 {
0338     do {
0339         if (copy_byte(wr, rep0))
0340             return -1;
0341         len--;
0342     } while (len != 0 && wr->buffer_pos < wr->header->dst_size);
0343
0344     return len;
0345 }
0346
0347 static inline int INIT process_bit0(struct writer *wr, struct rc *rc,
0348                      struct cstate *cst, uint16_t *p,
0349                      int pos_state, uint16_t *prob,
0350                      int lc, uint32_t literal_pos_mask) {
0351     int mi = 1;
0352     rc_update_bit_0(rc, prob);
0353     prob = (p + LZMA_LITERAL +
0354         (LZMA_LIT_SIZE
0355          * (((get_pos(wr) & literal_pos_mask) << lc)
0356             + (wr->previous_byte >> (8 - lc))))
0357         );
0358
0359     if (cst->state >= LZMA_NUM_LIT_STATES) {
0360         int match_byte = peek_old_byte(wr, cst->rep0);
0361         do {
0362             int bit;
0363             uint16_t *prob_lit;
0364
0365             match_byte <<= 1;
0366             bit = match_byte & 0x100;
0367             prob_lit = prob + 0x100 + bit + mi;
0368             if (rc_get_bit(rc, prob_lit, &mi)) {
0369                 if (!bit)
0370                     break;
0371             } else {
0372                 if (bit)
0373                     break;
0374             }
0375         } while (mi < 0x100);
0376     }
0377     while (mi < 0x100) {
0378         uint16_t *prob_lit = prob + mi;
0379         rc_get_bit(rc, prob_lit, &mi);
0380     }
0381     if (cst->state < 4)
0382         cst->state = 0;
0383     else if (cst->state < 10)
0384         cst->state -= 3;
0385     else
0386         cst->state -= 6;
0387
0388     return write_byte(wr, mi);
0389 }
0390
0391 static inline int INIT process_bit1(struct writer *wr, struct rc *rc,
0392                         struct cstate *cst, uint16_t *p,
0393                         int pos_state, uint16_t *prob) {
0394     int offset;
0395     uint16_t *prob_len;
0396     int num_bits;
0397     int len;
0398
0399     rc_update_bit_1(rc, prob);
0400     prob = p + LZMA_IS_REP + cst->state;
0401     if (rc_is_bit_0(rc, prob)) {
0402         rc_update_bit_0(rc, prob);
0403         cst->rep3 = cst->rep2;
0404         cst->rep2 = cst->rep1;
0405         cst->rep1 = cst->rep0;
0406         cst->state = cst->state < LZMA_NUM_LIT_STATES ? 0 : 3;
0407         prob = p + LZMA_LEN_CODER;
0408     } else {
0409         rc_update_bit_1(rc, prob);
0410         prob = p + LZMA_IS_REP_G0 + cst->state;
0411         if (rc_is_bit_0(rc, prob)) {
0412             rc_update_bit_0(rc, prob);
0413             prob = (p + LZMA_IS_REP_0_LONG
0414                 + (cst->state <<
0415                    LZMA_NUM_POS_BITS_MAX) +
0416                 pos_state);
0417             if (rc_is_bit_0(rc, prob)) {
0418                 rc_update_bit_0(rc, prob);
0419
0420                 cst->state = cst->state < LZMA_NUM_LIT_STATES ?
0421                     9 : 11;
0422                 return copy_byte(wr, cst->rep0);
0423             } else {
0424                 rc_update_bit_1(rc, prob);
0425             }
0426         } else {
0427             uint32_t distance;
0428
0429             rc_update_bit_1(rc, prob);
0430             prob = p + LZMA_IS_REP_G1 + cst->state;
0431             if (rc_is_bit_0(rc, prob)) {
0432                 rc_update_bit_0(rc, prob);
0433                 distance = cst->rep1;
0434             } else {
0435                 rc_update_bit_1(rc, prob);
0436                 prob = p + LZMA_IS_REP_G2 + cst->state;
0437                 if (rc_is_bit_0(rc, prob)) {
0438                     rc_update_bit_0(rc, prob);
0439                     distance = cst->rep2;
0440                 } else {
0441                     rc_update_bit_1(rc, prob);
0442                     distance = cst->rep3;
0443                     cst->rep3 = cst->rep2;
0444                 }
0445                 cst->rep2 = cst->rep1;
0446             }
0447             cst->rep1 = cst->rep0;
0448             cst->rep0 = distance;
0449         }
0450         cst->state = cst->state < LZMA_NUM_LIT_STATES ? 8 : 11;
0451         prob = p + LZMA_REP_LEN_CODER;
0452     }
0453
0454     prob_len = prob + LZMA_LEN_CHOICE;
0455     if (rc_is_bit_0(rc, prob_len)) {
0456         rc_update_bit_0(rc, prob_len);
0457         prob_len = (prob + LZMA_LEN_LOW
0458                 + (pos_state <<
0459                    LZMA_LEN_NUM_LOW_BITS));
0460         offset = 0;
0461         num_bits = LZMA_LEN_NUM_LOW_BITS;
0462     } else {
0463         rc_update_bit_1(rc, prob_len);
0464         prob_len = prob + LZMA_LEN_CHOICE_2;
0465         if (rc_is_bit_0(rc, prob_len)) {
0466             rc_update_bit_0(rc, prob_len);
0467             prob_len = (prob + LZMA_LEN_MID
0468                     + (pos_state <<
0469                        LZMA_LEN_NUM_MID_BITS));
0470             offset = 1 << LZMA_LEN_NUM_LOW_BITS;
0471             num_bits = LZMA_LEN_NUM_MID_BITS;
0472         } else {
0473             rc_update_bit_1(rc, prob_len);
0474             prob_len = prob + LZMA_LEN_HIGH;
0475             offset = ((1 << LZMA_LEN_NUM_LOW_BITS)
0476                   + (1 << LZMA_LEN_NUM_MID_BITS));
0477             num_bits = LZMA_LEN_NUM_HIGH_BITS;
0478         }
0479     }
0480
0481     rc_bit_tree_decode(rc, prob_len, num_bits, &len);
0482     len += offset;
0483
0484     if (cst->state < 4) {
0485         int pos_slot;
0486
0487         cst->state += LZMA_NUM_LIT_STATES;
0488         prob =
0489             p + LZMA_POS_SLOT +
0490             ((len <
0491               LZMA_NUM_LEN_TO_POS_STATES ? len :
0492               LZMA_NUM_LEN_TO_POS_STATES - 1)
0493              << LZMA_NUM_POS_SLOT_BITS);
0494         rc_bit_tree_decode(rc, prob,
0495                    LZMA_NUM_POS_SLOT_BITS,
0496                    &pos_slot);
0497         if (pos_slot >= LZMA_START_POS_MODEL_INDEX) {
0498             int i, mi;
0499             num_bits = (pos_slot >> 1) - 1;
0500             cst->rep0 = 2 | (pos_slot & 1);
0501             if (pos_slot < LZMA_END_POS_MODEL_INDEX) {
0502                 cst->rep0 <<= num_bits;
0503                 prob = p + LZMA_SPEC_POS +
0504                     cst->rep0 - pos_slot - 1;
0505             } else {
0506                 num_bits -= LZMA_NUM_ALIGN_BITS;
0507                 while (num_bits--)
0508                     cst->rep0 = (cst->rep0 << 1) |
0509                         rc_direct_bit(rc);
0510                 prob = p + LZMA_ALIGN;
0511                 cst->rep0 <<= LZMA_NUM_ALIGN_BITS;
0512                 num_bits = LZMA_NUM_ALIGN_BITS;
0513             }
0514             i = 1;
0515             mi = 1;
0516             while (num_bits--) {
0517                 if (rc_get_bit(rc, prob + mi, &mi))
0518                     cst->rep0 |= i;
0519                 i <<= 1;
0520             }
0521         } else
0522             cst->rep0 = pos_slot;
0523         if (++(cst->rep0) == 0)
0524             return 0;
0525         if (cst->rep0 > wr->header->dict_size
0526                 || cst->rep0 > get_pos(wr))
0527             return -1;
0528     }
0529
0530     len += LZMA_MATCH_MIN_LEN;
0531
0532     return copy_bytes(wr, cst->rep0, len);
0533 }
0534
0535
0536
0537 STATIC inline int INIT unlzma(unsigned char *buf, long in_len,
0538                   long (*fill)(void*, unsigned long),
0539                   long (*flush)(void*, unsigned long),
0540                   unsigned char *output,
0541                   long *posp,
0542                   void(*error)(char *x)
0543     )
0544 {
0545     struct lzma_header header;
0546     int lc, pb, lp;
0547     uint32_t pos_state_mask;
0548     uint32_t literal_pos_mask;
0549     uint16_t *p;
0550     int num_probs;
0551     struct rc rc;
0552     int i, mi;
0553     struct writer wr;
0554     struct cstate cst;
0555     unsigned char *inbuf;
0556     int ret = -1;
0557
0558     rc.error = error;
0559
0560     if (buf)
0561         inbuf = buf;
0562     else
0563         inbuf = malloc(LZMA_IOBUF_SIZE);
0564     if (!inbuf) {
0565         error("Could not allocate input buffer");
0566         goto exit_0;
0567     }
0568
0569     cst.state = 0;
0570     cst.rep0 = cst.rep1 = cst.rep2 = cst.rep3 = 1;
0571
0572     wr.header = &header;
0573     wr.flush = flush;
0574     wr.global_pos = 0;
0575     wr.previous_byte = 0;
0576     wr.buffer_pos = 0;
0577
0578     rc_init(&rc, fill, inbuf, in_len);
0579
0580     for (i = 0; i < sizeof(header); i++) {
0581         if (rc.ptr >= rc.buffer_end)
0582             rc_read(&rc);
0583         ((unsigned char *)&header)[i] = *rc.ptr++;
0584     }
0585
0586     if (header.pos >= (9 * 5 * 5)) {
0587         error("bad header");
0588         goto exit_1;
0589     }
0590
0591     mi = 0;
0592     lc = header.pos;
0593     while (lc >= 9) {
0594         mi++;
0595         lc -= 9;
0596     }
0597     pb = 0;
0598     lp = mi;
0599     while (lp >= 5) {
0600         pb++;
0601         lp -= 5;
0602     }
0603     pos_state_mask = (1 << pb) - 1;
0604     literal_pos_mask = (1 << lp) - 1;
0605
0606     ENDIAN_CONVERT(header.dict_size);
0607     ENDIAN_CONVERT(header.dst_size);
0608
0609     if (header.dict_size == 0)
0610         header.dict_size = 1;
0611
0612     if (output)
0613         wr.buffer = output;
0614     else {
0615         wr.bufsize = MIN(header.dst_size, header.dict_size);
0616         wr.buffer = large_malloc(wr.bufsize);
0617     }
0618     if (wr.buffer == NULL)
0619         goto exit_1;
0620
0621     num_probs = LZMA_BASE_SIZE + (LZMA_LIT_SIZE << (lc + lp));
0622     p = (uint16_t *) large_malloc(num_probs * sizeof(*p));
0623     if (p == NULL)
0624         goto exit_2;
0625     num_probs = LZMA_LITERAL + (LZMA_LIT_SIZE << (lc + lp));
0626     for (i = 0; i < num_probs; i++)
0627         p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1;
0628
0629     rc_init_code(&rc);
0630
0631     while (get_pos(&wr) < header.dst_size) {
0632         int pos_state = get_pos(&wr) & pos_state_mask;
0633         uint16_t *prob = p + LZMA_IS_MATCH +
0634             (cst.state << LZMA_NUM_POS_BITS_MAX) + pos_state;
0635         if (rc_is_bit_0(&rc, prob)) {
0636             if (process_bit0(&wr, &rc, &cst, p, pos_state, prob,
0637                     lc, literal_pos_mask)) {
0638                 error("LZMA data is corrupt");
0639                 goto exit_3;
0640             }
0641         } else {
0642             if (process_bit1(&wr, &rc, &cst, p, pos_state, prob)) {
0643                 error("LZMA data is corrupt");
0644                 goto exit_3;
0645             }
0646             if (cst.rep0 == 0)
0647                 break;
0648         }
0649         if (rc.buffer_size <= 0)
0650             goto exit_3;
0651     }
0652
0653     if (posp)
0654         *posp = rc.ptr-rc.buffer;
0655     if (!wr.flush || wr.flush(wr.buffer, wr.buffer_pos) == wr.buffer_pos)
0656         ret = 0;
0657 exit_3:
0658     large_free(p);
0659 exit_2:
0660     if (!output)
0661         large_free(wr.buffer);
0662 exit_1:
0663     if (!buf)
0664         free(inbuf);
0665 exit_0:
0666     return ret;
0667 }
0668
0669 #ifdef PREBOOT
0670 STATIC int INIT __decompress(unsigned char *buf, long in_len,
0671                   long (*fill)(void*, unsigned long),
0672                   long (*flush)(void*, unsigned long),
0673                   unsigned char *output, long out_len,
0674                   long *posp,
0675                   void (*error)(char *x))
0676 {
0677     return unlzma(buf, in_len - 4, fill, flush, output, posp, error);
0678 }
0679 #endif