fs/cramfs/uncompress.c

   1 /*
   2  * uncompress.c
   3  *
   4  * Copyright (C) 1999 Linus Torvalds
   5  * Copyright (C) 2000-2002 Transmeta Corporation
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License (Version 2) as
   9  * published by the Free Software Foundation.
  10  *
  11  * cramfs interfaces to the uncompression library. There's really just
  12  * three entrypoints:
  13  *
  14  *  - cramfs_uncompress_init() - called to initialize the thing.
  15  *  - cramfs_uncompress_exit() - tell me when you're done
  16  *  - cramfs_uncompress_block() - uncompress a block.
  17  *
  18  * NOTE NOTE NOTE! The uncompression is entirely single-threaded. We
  19  * only have one stream, and we'll initialize it only once even if it
  20  * then is used by multiple filesystems.
  21  */
  22
  23 #include <common.h>
  24 #include <malloc.h>
  25 #include <watchdog.h>
  26 #include <zlib.h>
  27
  28 #if defined(CONFIG_CMD_CRAMFS)
  29
  30 static z_stream stream;
  31
  32 void *zalloc(void *, unsigned, unsigned);
  33 void zfree(void *, void *, unsigned);
  34
  35 /* Returns length of decompressed data. */
  36 int cramfs_uncompress_block (void *dst, void *src, int srclen)
  37 {
  38         int err;
  39
  40         inflateReset (&stream);
  41
  42         stream.next_in = src;
  43         stream.avail_in = srclen;
  44
  45         stream.next_out = dst;
  46         stream.avail_out = 4096 * 2;
  47
  48         err = inflate (&stream, Z_FINISH);
  49
  50         if (err != Z_STREAM_END)
  51                 goto err;
  52         return stream.total_out;
  53
  54       err:
  55         /*printf ("Error %d while decompressing!\n", err); */
  56         /*printf ("%p(%d)->%p\n", src, srclen, dst); */
  57         return -1;
  58 }
  59
  60 int cramfs_uncompress_init (void)
  61 {
  62         int err;
  63
  64         stream.zalloc = zalloc;
  65         stream.zfree = zfree;
  66         stream.next_in = 0;
  67         stream.avail_in = 0;
  68
  69 #if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
  70         stream.outcb = (cb_func) WATCHDOG_RESET;
  71 #else
  72         stream.outcb = Z_NULL;
  73 #endif /* CONFIG_HW_WATCHDOG */
  74
  75         err = inflateInit (&stream);
  76         if (err != Z_OK) {
  77                 printf ("Error: inflateInit2() returned %d\n", err);
  78                 return -1;
  79         }
  80
  81         return 0;
  82 }
  83
  84 int cramfs_uncompress_exit (void)
  85 {
  86         inflateEnd (&stream);
  87         return 0;
  88 }
  89
  90 #endif /* CFG_FS_CRAMFS */