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-rw-r--r--fs/cramfs/cramfs_fs.h133
1 files changed, 133 insertions, 0 deletions
diff --git a/fs/cramfs/cramfs_fs.h b/fs/cramfs/cramfs_fs.h
new file mode 100644
index 0000000..78cc9ec
--- /dev/null
+++ b/fs/cramfs/cramfs_fs.h
@@ -0,0 +1,133 @@
+#ifndef __CRAMFS_FS_H
+#define __CRAMFS_FS_H
+
+/* Uncompression interfaces to the underlying zlib */
+int cramfs_uncompress_block (void *dst, void *src, int srclen);
+int cramfs_uncompress_init (void);
+
+#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
+
+#endif /* not __CRAMFS_FS_H */