| #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 ) |
| |
| #if (__BYTE_ORDER == __LITTLE_ENDIAN) || (defined(CONFIG_COMCERTO) && (__BYTE_ORDER == __BIG_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 */ |