LXR uboot/include/cramfs/cramfs

   1#ifndef __CRAMFS_H
   2#define __CRAMFS_H
   3
   4#define CRAMFS_MAGIC            0x28cd3d45      /* some random number */
   5#define CRAMFS_SIGNATURE        "Compressed ROMFS"
   6
   7/*
   8 * Width of various bitfields in struct cramfs_inode.
   9 * Primarily used to generate warnings in mkcramfs.
  10 */
  11#define CRAMFS_MODE_WIDTH       16
  12#define CRAMFS_UID_WIDTH        16
  13#define CRAMFS_SIZE_WIDTH       24
  14#define CRAMFS_GID_WIDTH        8
  15#define CRAMFS_NAMELEN_WIDTH    6
  16#define CRAMFS_OFFSET_WIDTH     26
  17
  18/*
  19 * Since inode.namelen is a unsigned 6-bit number, the maximum cramfs
  20 * path length is 63 << 2 = 252.
  21 */
  22#define CRAMFS_MAXPATHLEN (((1 << CRAMFS_NAMELEN_WIDTH) - 1) << 2)
  23
  24/*
  25 * Reasonably terse representation of the inode data.
  26 */
  27struct cramfs_inode {
  28        u32 mode:CRAMFS_MODE_WIDTH, uid:CRAMFS_UID_WIDTH;
  29
  30        /* SIZE for device files is i_rdev */
  31        u32 size:CRAMFS_SIZE_WIDTH, gid:CRAMFS_GID_WIDTH;
  32
  33        /* NAMELEN is the length of the file name, divided by 4 and
  34           rounded up.  (cramfs doesn't support hard links.) */
  35        /* OFFSET: For symlinks and non-empty regular files, this
  36           contains the offset (divided by 4) of the file data in
  37           compressed form (starting with an array of block pointers;
  38           see README).  For non-empty directories it is the offset
  39           (divided by 4) of the inode of the first file in that
  40           directory.  For anything else, offset is zero. */
  41        u32 namelen:CRAMFS_NAMELEN_WIDTH, offset:CRAMFS_OFFSET_WIDTH;
  42};
  43
  44struct cramfs_info {
  45        u32 crc;
  46        u32 edition;
  47        u32 blocks;
  48        u32 files;
  49};
  50
  51/*
  52 * Superblock information at the beginning of the FS.
  53 */
  54struct cramfs_super {
  55        u32 magic;                      /* 0x28cd3d45 - random number */
  56        u32 size;                       /* length in bytes */
  57        u32 flags;                      /* feature flags */
  58        u32 future;                     /* reserved for future use */
  59        u8 signature[16];               /* "Compressed ROMFS" */
  60        struct cramfs_info fsid;        /* unique filesystem info */
  61        u8 name[16];                    /* user-defined name */
  62        struct cramfs_inode root;       /* root inode data */
  63};
  64
  65/*
  66 * Feature flags
  67 *
  68 * 0x00000000 - 0x000000ff: features that work for all past kernels
  69 * 0x00000100 - 0xffffffff: features that don't work for past kernels
  70 */
  71#define CRAMFS_FLAG_FSID_VERSION_2      0x00000001      /* fsid version #2 */
  72#define CRAMFS_FLAG_SORTED_DIRS         0x00000002      /* sorted dirs */
  73#define CRAMFS_FLAG_HOLES               0x00000100      /* support for holes */
  74#define CRAMFS_FLAG_WRONG_SIGNATURE     0x00000200      /* reserved */
  75#define CRAMFS_FLAG_SHIFTED_ROOT_OFFSET 0x00000400      /* shifted root fs */
  76
  77/*
  78 * Valid values in super.flags.  Currently we refuse to mount
  79 * if (flags & ~CRAMFS_SUPPORTED_FLAGS).  Maybe that should be
  80 * changed to test super.future instead.
  81 */
  82#define CRAMFS_SUPPORTED_FLAGS  ( 0x000000ff \
  83                                | CRAMFS_FLAG_HOLES \
  84                                | CRAMFS_FLAG_WRONG_SIGNATURE \
  85                                | CRAMFS_FLAG_SHIFTED_ROOT_OFFSET )
  86
  87#define CRAMFS_16(x)    (x)
  88#define CRAMFS_24(x)    (x)
  89#define CRAMFS_32(x)    (x)
  90#define CRAMFS_GET_NAMELEN(x)   ((x)->namelen)
  91#define CRAMFS_GET_OFFSET(x)    ((x)->offset)
  92#define CRAMFS_SET_OFFSET(x,y)  ((x)->offset = (y))
  93#define CRAMFS_SET_NAMELEN(x,y) ((x)->namelen = (y))
  94
  95/* Uncompression interfaces to the underlying zlib */
  96int cramfs_uncompress_block(void *dst, void *src, int srclen);
  97int cramfs_uncompress_init(void);
  98int cramfs_uncompress_exit(void);
  99
 100#endif  /* __CRAMFS_H */
 101