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#ifndef __CRAMFS_H
#define __CRAMFS_H
#define CRAMFS_MAGIC 0x28cd3d45 /* some random number */
#define CRAMFS_SIGNATURE "Compressed ROMFS"
/*
* Width of various bitfields in struct cramfs_inode.
* Primarily used to generate warnings in mkcramfs.
*/
#define CRAMFS_MODE_WIDTH 16
#define CRAMFS_UID_WIDTH 16
#define CRAMFS_SIZE_WIDTH 24
#define CRAMFS_GID_WIDTH 8
#define CRAMFS_NAMELEN_WIDTH 6
#define CRAMFS_OFFSET_WIDTH 26
/*
* Since inode.namelen is a unsigned 6-bit number, the maximum cramfs
* path length is 63 << 2 = 252.
*/
#define CRAMFS_MAXPATHLEN (((1 << CRAMFS_NAMELEN_WIDTH) - 1) << 2)
/*
* Reasonably terse representation of the inode data.
*/
struct cramfs_inode {
u32 mode:CRAMFS_MODE_WIDTH, uid:CRAMFS_UID_WIDTH;
/* SIZE for device files is i_rdev */
u32 size:CRAMFS_SIZE_WIDTH, gid:CRAMFS_GID_WIDTH;
/* NAMELEN is the length of the file name, divided by 4 and
rounded up. (cramfs doesn't support hard links.) */
/* OFFSET: For symlinks and non-empty regular files, this
contains the offset (divided by 4) of the file data in
compressed form (starting with an array of block pointers;
see README). For non-empty directories it is the offset
(divided by 4) of the inode of the first file in that
directory. For anything else, offset is zero. */
u32 namelen:CRAMFS_NAMELEN_WIDTH, offset:CRAMFS_OFFSET_WIDTH;
};
struct cramfs_info {
u32 crc;
u32 edition;
u32 blocks;
u32 files;
};
/*
* Superblock information at the beginning of the FS.
*/
struct cramfs_super {
u32 magic; /* 0x28cd3d45 - random number */
u32 size; /* length in bytes */
u32 flags; /* feature flags */
u32 future; /* reserved for future use */
u8 signature[16]; /* "Compressed ROMFS" */
struct cramfs_info fsid; /* unique filesystem info */
u8 name[16]; /* user-defined name */
struct cramfs_inode root; /* root inode data */
};
/*
* Feature flags
*
* 0x00000000 - 0x000000ff: features that work for all past kernels
* 0x00000100 - 0xffffffff: features that don't work for past kernels
*/
#define CRAMFS_FLAG_FSID_VERSION_2 0x00000001 /* fsid version #2 */
#define CRAMFS_FLAG_SORTED_DIRS 0x00000002 /* sorted dirs */
#define CRAMFS_FLAG_HOLES 0x00000100 /* support for holes */
#define CRAMFS_FLAG_WRONG_SIGNATURE 0x00000200 /* reserved */
#define CRAMFS_FLAG_SHIFTED_ROOT_OFFSET 0x00000400 /* shifted root fs */
/*
* Valid values in super.flags. Currently we refuse to mount
* if (flags & ~CRAMFS_SUPPORTED_FLAGS). Maybe that should be
* changed to test super.future instead.
*/
#define CRAMFS_SUPPORTED_FLAGS ( 0x000000ff \
| CRAMFS_FLAG_HOLES \
| CRAMFS_FLAG_WRONG_SIGNATURE \
| CRAMFS_FLAG_SHIFTED_ROOT_OFFSET )
/*
* Since cramfs is little-endian, provide macros to swab the bitfields.
*/
#ifndef __BYTE_ORDER
#if defined(__LITTLE_ENDIAN) && !defined(__BIG_ENDIAN)
#define __BYTE_ORDER __LITTLE_ENDIAN
#elif defined(__BIG_ENDIAN) && !defined(__LITTLE_ENDIAN)
#define __BYTE_ORDER __BIG_ENDIAN
#else
#error "unable to define __BYTE_ORDER"
#endif
#endif /* not __BYTE_ORDER */
#if __BYTE_ORDER == __LITTLE_ENDIAN
#define CRAMFS_16(x) (x)
#define CRAMFS_24(x) (x)
#define CRAMFS_32(x) (x)
#define CRAMFS_GET_NAMELEN(x) ((x)->namelen)
#define CRAMFS_GET_OFFSET(x) ((x)->offset)
#define CRAMFS_SET_OFFSET(x,y) ((x)->offset = (y))
#define CRAMFS_SET_NAMELEN(x,y) ((x)->namelen = (y))
#elif __BYTE_ORDER == __BIG_ENDIAN
#ifdef __KERNEL__
#define CRAMFS_16(x) swab16(x)
#define CRAMFS_24(x) ((swab32(x)) >> 8)
#define CRAMFS_32(x) swab32(x)
#else /* not __KERNEL__ */
#define CRAMFS_16(x) bswap_16(x)
#define CRAMFS_24(x) ((bswap_32(x)) >> 8)
#define CRAMFS_32(x) bswap_32(x)
#endif /* not __KERNEL__ */
#define CRAMFS_GET_NAMELEN(x) (((u8*)(x))[8] & 0x3f)
#define CRAMFS_GET_OFFSET(x) ((CRAMFS_24(((u32*)(x))[2] & 0xffffff) << 2) |\
((((u32*)(x))[2] & 0xc0000000) >> 30))
#define CRAMFS_SET_NAMELEN(x,y) (((u8*)(x))[8] = (((0x3f & (y))) | \
(0xc0 & ((u8*)(x))[8])))
#define CRAMFS_SET_OFFSET(x,y) (((u32*)(x))[2] = (((y) & 3) << 30) | \
CRAMFS_24((((y) & 0x03ffffff) >> 2)) | \
(((u32)(((u8*)(x))[8] & 0x3f)) << 24))
#else
#error "__BYTE_ORDER must be __LITTLE_ENDIAN or __BIG_ENDIAN"
#endif
/* Uncompression interfaces to the underlying zlib */
int cramfs_uncompress_block(void *dst, void *src, int srclen);
int cramfs_uncompress_init(void);
int cramfs_uncompress_exit(void);
#endif /* __CRAMFS_H */
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