From dd875c767e6fb0f4fecfb799b706d84562a7acee Mon Sep 17 00:00:00 2001
From: wdenk <wdenk>
Date: Sat, 3 Jan 2004 21:24:46 +0000
Subject: * Patch by Robert Schwebel, 15 Dec 2003:   add support for cramfs
 (uses JFFS2 command interface)

---
 include/cramfs/cramfs_fs.h | 98 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)
 create mode 100644 include/cramfs/cramfs_fs.h

(limited to 'include/cramfs/cramfs_fs.h')

diff --git a/include/cramfs/cramfs_fs.h b/include/cramfs/cramfs_fs.h
new file mode 100644
index 0000000000..7b292c0c1e
--- /dev/null
+++ b/include/cramfs/cramfs_fs.h
@@ -0,0 +1,98 @@
+#ifndef __CRAMFS_H
+#define __CRAMFS_H
+
+#ifndef __KERNEL__
+
+typedef unsigned char u8;
+typedef unsigned short u16;
+typedef unsigned int u32;
+
+#endif
+
+#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 )
+
+/* 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
-- 
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