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_JFFS2)
  29
  30 static z_stream stream;
  31
  32 #define ZALLOC_ALIGNMENT        16
  33
  34 static void *zalloc (void *x, unsigned items, unsigned size)
  35 {
  36         void *p;
  37
  38         size *= items;
  39         size = (size + ZALLOC_ALIGNMENT - 1) & ~(ZALLOC_ALIGNMENT - 1);
  40
  41         p = malloc (size);
  42
  43         return (p);
  44 }
  45
  46 static void zfree (void *x, void *addr, unsigned nb)
  47 {
  48         free (addr);
  49 }
  50
  51 /* Returns length of decompressed data. */
  52 int cramfs_uncompress_block (void *dst, void *src, int srclen)
  53 {
  54         int err;
  55
  56         inflateReset (&stream);
  57
  58         stream.next_in = src;
  59         stream.avail_in = srclen;
  60
  61         stream.next_out = dst;
  62         stream.avail_out = 4096 * 2;
  63
  64         err = inflate (&stream, Z_FINISH);
  65
  66         if (err != Z_STREAM_END)
  67                 goto err;
  68         return stream.total_out;
  69
  70       err:
  71         /*printf ("Error %d while decompressing!\n", err); */
  72         /*printf ("%p(%d)->%p\n", src, srclen, dst); */
  73         return -1;
  74 }
  75
  76 int cramfs_uncompress_init (void)
  77 {
  78         int err;
  79
  80         stream.zalloc = zalloc;
  81         stream.zfree = zfree;
  82         stream.next_in = 0;
  83         stream.avail_in = 0;
  84
  85 #if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
  86         stream.outcb = (cb_func) WATCHDOG_RESET;
  87 #else
  88         stream.outcb = Z_NULL;
  89 #endif /* CONFIG_HW_WATCHDOG */
  90
  91         err = inflateInit (&stream);
  92         if (err != Z_OK) {
  93                 printf ("Error: inflateInit2() returned %d\n", err);
  94                 return -1;
  95         }
  96
  97         return 0;
  98 }
  99
 100 int cramfs_uncompress_exit (void)
 101 {
 102         inflateEnd (&stream);
 103         return 0;
 104 }
 105
 106 #endif /* CFG_FS_CRAMFS */