[thirdparty/util-linux.git] / disk-utils / cramfs.h

#ifndef __CRAMFS_H
#define __CRAMFS_H

typedef unsigned char u8;
typedef unsigned short u16;
typedef unsigned int u32;

#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


/*
 * Reasonably terse representation of the inode data.
 */
struct cramfs_inode {
	u32 mode:16, uid:16;
	/* SIZE for device files is i_rdev */
	u32 size:24, gid:8;
	/* 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:6, offset:26;
};

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;		/* Not used.  mkcramfs currently
                                   writes a constant 1<<16 here. */
	u32 flags;		/* 0 */
	u32 future;		/* 0 */
	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 */
};

#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 (0xff)

/* Uncompression interfaces to the underlying zlib */
int cramfs_uncompress_block(void *dst, int dstlen, void *src, int srclen);
int cramfs_uncompress_init(void);
int cramfs_uncompress_exit(void);

#endif
Commit	Line	Data
63cccae4 KZ	1	#ifndef __CRAMFS_H
	2	#define __CRAMFS_H
	3
	4	typedef unsigned char u8;
	5	typedef unsigned short u16;
	6	typedef unsigned int u32;
	7
	8	#define CRAMFS_MAGIC 0x28cd3d45 /* some random number */
	9	#define CRAMFS_SIGNATURE "Compressed ROMFS"
	10
	11	/*
	12	* Width of various bitfields in struct cramfs_inode.
	13	* Primarily used to generate warnings in mkcramfs.
	14	*/
	15	#define CRAMFS_MODE_WIDTH 16
	16	#define CRAMFS_UID_WIDTH 16
	17	#define CRAMFS_SIZE_WIDTH 24
	18	#define CRAMFS_GID_WIDTH 8
	19	#define CRAMFS_NAMELEN_WIDTH 6
	20	#define CRAMFS_OFFSET_WIDTH 26
	21
	22
	23	/*
	24	* Reasonably terse representation of the inode data.
	25	*/
	26	struct cramfs_inode {
	27	u32 mode:16, uid:16;
	28	/* SIZE for device files is i_rdev */
	29	u32 size:24, gid:8;
	30	/* NAMELEN is the length of the file name, divided by 4 and
	31	rounded up. (cramfs doesn't support hard links.) */
	32	/* OFFSET: For symlinks and non-empty regular files, this
	33	contains the offset (divided by 4) of the file data in
	34	compressed form (starting with an array of block pointers;
	35	see README). For non-empty directories it is the offset
	36	(divided by 4) of the inode of the first file in that
	37	directory. For anything else, offset is zero. */
	38	u32 namelen:6, offset:26;
	39	};
	40
	41	struct cramfs_info {
	42	u32 crc;
	43	u32 edition;
	44	u32 blocks;
	45	u32 files;
	46	};
	47
	48	/*
	49	* Superblock information at the beginning of the FS.
	50	*/
	51	struct cramfs_super {
	52	u32 magic; /* 0x28cd3d45 - random number */
	53	u32 size; /* Not used. mkcramfs currently
	54	writes a constant 1<<16 here. */
	55	u32 flags; /* 0 */
	56	u32 future; /* 0 */
	57	u8 signature[16]; /* "Compressed ROMFS" */
	58	struct cramfs_info fsid;/* unique filesystem info */
	59	u8 name[16]; /* user-defined name */
	60	struct cramfs_inode root; /* Root inode data */
	61	};
	62
	63	#define CRAMFS_FLAG_FSID_VERSION_2 0x00000001 /* fsid version #2 */
	64	#define CRAMFS_FLAG_SORTED_DIRS 0x00000002 /* sorted dirs */
65	#define CRAMFS_FLAG_HOLES 0x00000100 /* support for holes */
66	#define CRAMFS_FLAG_WRONG_SIGNATURE 0x00000200 /* reserved */
67	#define CRAMFS_FLAG_SHIFTED_ROOT_OFFSET 0x00000400 /* shifted root fs */
68
69	/*
70	* Valid values in super.flags. Currently we refuse to mount
71	* if (flags & ~CRAMFS_SUPPORTED_FLAGS). Maybe that should be
72	* changed to test super.future instead.
73	*/
74	#define CRAMFS_SUPPORTED_FLAGS (0xff)
75
76	/* Uncompression interfaces to the underlying zlib */
77	int cramfs_uncompress_block(void dst, int dstlen, void src, int srclen);
78	int cramfs_uncompress_init(void);
79	int cramfs_uncompress_exit(void);
80
81	#endif