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 <u-boot/zlib.h>
  27
  28 static z_stream stream;
  29
  30 /* Returns length of decompressed data. */
  31 int cramfs_uncompress_block (void *dst, void *src, int srclen)
  32 {
  33         int err;
  34
  35         inflateReset (&stream);
  36
  37         stream.next_in = src;
  38         stream.avail_in = srclen;
  39
  40         stream.next_out = dst;
  41         stream.avail_out = 4096 * 2;
  42
  43         err = inflate (&stream, Z_FINISH);
  44
  45         if (err != Z_STREAM_END)
  46                 goto err;
  47         return stream.total_out;
  48
  49       err:
  50         /*printf ("Error %d while decompressing!\n", err); */
  51         /*printf ("%p(%d)->%p\n", src, srclen, dst); */
  52         return -1;
  53 }
  54
  55 int cramfs_uncompress_init (void)
  56 {
  57         int err;
  58
  59         stream.zalloc = gzalloc;
  60         stream.zfree = gzfree;
  61         stream.next_in = 0;
  62         stream.avail_in = 0;
  63
  64 #if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
  65         stream.outcb = (cb_func) WATCHDOG_RESET;
  66 #else
  67         stream.outcb = Z_NULL;
  68 #endif /* CONFIG_HW_WATCHDOG */
  69
  70         err = inflateInit (&stream);
  71         if (err != Z_OK) {
  72                 printf ("Error: inflateInit2() returned %d\n", err);
  73                 return -1;
  74         }
  75
  76         return 0;
  77 }
  78
  79 int cramfs_uncompress_exit (void)
  80 {
  81         inflateEnd (&stream);
  82         return 0;
  83 }