1 /*
2 * GRUB -- GRand Unified Bootloader
3 * Copyright (C) 1999,2000,2001,2002,2003,2004 Free Software Foundation, Inc.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 */
19 /*
20 * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
21 * Use is subject to license terms.
22 */
23
24 #include "fsys_zfs.h"
25
26 #define MATCH_BITS 6
27 #define MATCH_MIN 3
28 #define OFFSET_MASK ((1 << (16 - MATCH_BITS)) - 1)
29
30
31 /*ARGSUSED*/
32 int
lzjb_decompress(void * s_start,void * d_start,size_t s_len,size_t d_len)33 lzjb_decompress(void *s_start, void *d_start, size_t s_len, size_t d_len)
34 {
35 uchar_t *src = s_start;
36 uchar_t *dst = d_start;
37 uchar_t *d_end = (uchar_t *)d_start + d_len;
38 uchar_t *cpy, copymap;
39 int copymask = 1 << (NBBY - 1);
40
41 while (dst < d_end) {
42 if ((copymask <<= 1) == (1 << NBBY)) {
43 copymask = 1;
44 copymap = *src++;
45 }
46 if (copymap & copymask) {
47 int mlen = (src[0] >> (NBBY - MATCH_BITS)) + MATCH_MIN;
48 int offset = ((src[0] << NBBY) | src[1]) & OFFSET_MASK;
49 src += 2;
50 if ((cpy = dst - offset) < (uchar_t *)d_start)
51 return (-1);
52 while (--mlen >= 0 && dst < d_end)
53 *dst++ = *cpy++;
54 } else {
55 *dst++ = *src++;
56 }
57 }
58 return (0);
59 }
60