* Patch by Robert Schwebel, 15 Dec 2003:

  add support for cramfs (uses JFFS2 command interface)

1 files changed, 368 insertions, 0 deletions

diff --git a/fs/cramfs/cramfs.c b/fs/cramfs/cramfs.c
new file mode 100644
index 0000000..1e35104
--- /dev/null
+++ b/fs/cramfs/cramfs.c
@@ -0,0 +1,368 @@
+/*
+ * cramfs.c
+ *
+ * Copyright (C) 1999 Linus Torvalds
+ *
+ * Copyright (C) 2000-2002 Transmeta Corporation
+ *
+ * Copyright (C) 2003 Kai-Uwe Bloem,
+ * Auerswald GmbH & Co KG, <linux-development@auerswald.de>
+ * - adapted from the www.tuxbox.org u-boot tree, added "ls" command
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (Version 2) as
+ * published by the Free Software Foundation.
+ *
+ * Compressed ROM filesystem for Linux.
+ *
+ * TODO:
+ * add support for resolving symbolic links
+ */
+
+/*
+ * These are the VFS interfaces to the compressed ROM filesystem.
+ * The actual compression is based on zlib, see the other files.
+ */
+
+#include <common.h>
+#include <malloc.h>
+
+#if (CONFIG_COMMANDS & CFG_CMD_JFFS2)
+
+#include <asm/byteorder.h>
+#include <linux/stat.h>
+#include <jffs2/load_kernel.h>
+#include "cramfs_fs.h"
+
+/* These two macros may change in future, to provide better st_ino
+   semantics. */
+#define CRAMINO(x)	(CRAMFS_GET_OFFSET(x) ? CRAMFS_GET_OFFSET(x)<<2 : 1)
+#define OFFSET(x)	((x)->i_ino)
+
+struct cramfs_super super;
+
+static int cramfs_read_super (struct part_info *info)
+{
+	unsigned long root_offset;
+
+	/* Read the first block and get the superblock from it */
+	memcpy (&super, (void *) info->offset, sizeof (super));
+
+	/* Do sanity checks on the superblock */
+	if (super.magic != CRAMFS_32 (CRAMFS_MAGIC)) {
+		/* check at 512 byte offset */
+		memcpy (&super, (void *) info->offset + 512, sizeof (super));
+		if (super.magic != CRAMFS_32 (CRAMFS_MAGIC)) {
+			printf ("cramfs: wrong magic\n");
+			return -1;
+		}
+	}
+
+	/* flags is reused several times, so swab it once */
+	super.flags = CRAMFS_32 (super.flags);
+	super.size = CRAMFS_32 (super.size);
+
+	/* get feature flags first */
+	if (super.flags & ~CRAMFS_SUPPORTED_FLAGS) {
+		printf ("cramfs: unsupported filesystem features\n");
+		return -1;
+	}
+
+	/* Check that the root inode is in a sane state */
+	if (!S_ISDIR (CRAMFS_16 (super.root.mode))) {
+		printf ("cramfs: root is not a directory\n");
+		return -1;
+	}
+	root_offset = CRAMFS_GET_OFFSET (&(super.root)) << 2;
+	if (root_offset == 0) {
+		printf ("cramfs: empty filesystem");
+	} else if (!(super.flags & CRAMFS_FLAG_SHIFTED_ROOT_OFFSET) &&
+		   ((root_offset != sizeof (struct cramfs_super)) &&
+		    (root_offset != 512 + sizeof (struct cramfs_super)))) {
+		printf ("cramfs: bad root offset %lu\n", root_offset);
+		return -1;
+	}
+
+	return 0;
+}
+
+static unsigned long cramfs_resolve (char *begin, unsigned long offset,
+				     unsigned long size, int raw,
+				     char *filename)
+{
+	unsigned long inodeoffset = 0, nextoffset;
+
+	while (inodeoffset < size) {
+		struct cramfs_inode *inode;
+		char *name;
+		int namelen;
+
+		inode = (struct cramfs_inode *) (begin + offset +
+						 inodeoffset);
+
+		/*
+		 * Namelengths on disk are shifted by two
+		 * and the name padded out to 4-byte boundaries
+		 * with zeroes.
+		 */
+		namelen = CRAMFS_GET_NAMELEN (inode) << 2;
+		name = (char *) inode + sizeof (struct cramfs_inode);
+
+		nextoffset =
+			inodeoffset + sizeof (struct cramfs_inode) + namelen;
+
+		for (;;) {
+			if (!namelen)
+				return -1;
+			if (name[namelen - 1])
+				break;
+			namelen--;
+		}
+
+		if (!strncmp (filename, name, namelen)) {
+			char *p = strtok (NULL, "/");
+
+			if (raw && (p == NULL || *p == '\0'))
+				return offset + inodeoffset;
+
+			if (S_ISDIR (CRAMFS_16 (inode->mode))) {
+				return cramfs_resolve (begin,
+						       CRAMFS_GET_OFFSET
+						       (inode) << 2,
+						       CRAMFS_24 (inode->
+								  size), raw,
+						       p);
+			} else if (S_ISREG (CRAMFS_16 (inode->mode))) {
+				return offset + inodeoffset;
+			} else {
+				printf ("%*.*s: unsupported file type (%x)\n",
+					namelen, namelen, name,
+					CRAMFS_16 (inode->mode));
+				return 0;
+			}
+		}
+
+		inodeoffset = nextoffset;
+	}
+
+	printf ("can't find corresponding entry\n");
+	return 0;
+}
+
+static int cramfs_uncompress (char *begin, unsigned long offset,
+			      unsigned long loadoffset)
+{
+	struct cramfs_inode *inode = (struct cramfs_inode *) (begin + offset);
+	unsigned long *block_ptrs = (unsigned long *)
+		(begin + (CRAMFS_GET_OFFSET (inode) << 2));
+	unsigned long curr_block = (CRAMFS_GET_OFFSET (inode) +
+				    (((CRAMFS_24 (inode->size)) +
+				      4095) >> 12)) << 2;
+	int size, total_size = 0;
+	int i;
+
+	cramfs_uncompress_init ();
+
+	for (i = 0; i < ((CRAMFS_24 (inode->size) + 4095) >> 12); i++) {
+		size = cramfs_uncompress_block ((void *) loadoffset,
+						(void *) (begin + curr_block),
+						(CRAMFS_32 (block_ptrs[i]) -
+						 curr_block));
+		if (size < 0)
+			return size;
+		loadoffset += size;
+		total_size += size;
+		curr_block = CRAMFS_32 (block_ptrs[i]);
+	}
+
+	cramfs_uncompress_exit ();
+	return total_size;
+}
+
+int cramfs_load (char *loadoffset, struct part_info *info, char *filename)
+{
+	unsigned long offset;
+
+	if (cramfs_read_super (info))
+		return -1;
+
+	offset = cramfs_resolve (info->offset,
+				 CRAMFS_GET_OFFSET (&(super.root)) << 2,
+				 CRAMFS_24 (super.root.size), 0,
+				 strtok (filename, "/"));
+
+	if (offset <= 0)
+		return offset;
+
+	return cramfs_uncompress (info->offset, offset,
+				  (unsigned long) loadoffset);
+}
+
+static char *mkmodestr (unsigned long mode, char *str)
+{
+	static const char *l = "xwr";
+	int mask = 1, i;
+	char c;
+
+	switch (mode & S_IFMT) {
+	case S_IFDIR:	str[0] = 'd'; break;
+	case S_IFBLK:	str[0] = 'b'; break;
+	case S_IFCHR:	str[0] = 'c'; break;
+	case S_IFIFO:	str[0] = 'f'; break;
+	case S_IFLNK:	str[0] = 'l'; break;
+	case S_IFSOCK:	str[0] = 's'; break;
+	case S_IFREG:	str[0] = '-'; break;
+	default: str[0] = '?'; break;
+	}
+
+	for (i = 0; i < 9; i++) {
+		c = l[i % 3];
+		str[9 - i] = (mode & mask) ? c : '-';
+		mask = mask << 1;
+	}
+
+	if (mode & S_ISUID) str[3] = (mode & S_IXUSR) ? 's' : 'S';
+	if (mode & S_ISGID) str[6] = (mode & S_IXGRP) ? 's' : 'S';
+	if (mode & S_ISVTX) str[9] = (mode & S_IXOTH) ? 't' : 'T';
+	str[10] = '\0';
+	return str;
+}
+
+static int cramfs_list_inode (struct part_info *info, unsigned long offset)
+{
+	struct cramfs_inode *inode = (struct cramfs_inode *)
+		(info->offset + offset);
+	char *name, str[20];
+	int namelen, nextoff;
+
+	/*
+	 * Namelengths on disk are shifted by two
+	 * and the name padded out to 4-byte boundaries
+	 * with zeroes.
+	 */
+	namelen = CRAMFS_GET_NAMELEN (inode) << 2;
+	name = (char *) inode + sizeof (struct cramfs_inode);
+	nextoff = namelen;
+
+	for (;;) {
+		if (!namelen)
+			return namelen;
+		if (name[namelen - 1])
+			break;
+		namelen--;
+	}
+
+	printf (" %s %8d %*.*s", mkmodestr (CRAMFS_16 (inode->mode), str),
+		CRAMFS_24 (inode->size), namelen, namelen, name);
+
+	if ((CRAMFS_16 (inode->mode) & S_IFMT) == S_IFLNK) {
+		/* symbolic link.
+		 * Unpack the link target, trusting in the inode's size field.
+		 */
+		unsigned long size = CRAMFS_24 (inode->size);
+		char *link = malloc (size);
+
+		if (link != NULL && cramfs_uncompress (info->offset, offset,
+						       (unsigned long) link)
+		    == size)
+			printf (" -> %*.*s\n", (int) size, (int) size, link);
+		else
+			printf (" [Error reading link]\n");
+		if (link)
+			free (link);
+	} else
+		printf ("\n");
+
+	return nextoff;
+}
+
+int cramfs_ls (struct part_info *info, char *filename)
+{
+	struct cramfs_inode *inode;
+	unsigned long inodeoffset = 0, nextoffset;
+	unsigned long offset, size;
+
+	if (cramfs_read_super (info))
+		return -1;
+
+	if (strlen (filename) == 0 || !strcmp (filename, "/")) {
+		/* Root directory. Use root inode in super block */
+		offset = CRAMFS_GET_OFFSET (&(super.root)) << 2;
+		size = CRAMFS_24 (super.root.size);
+	} else {
+		/* Resolve the path */
+		offset = cramfs_resolve (info->offset,
+					 CRAMFS_GET_OFFSET (&(super.root)) <<
+					 2, CRAMFS_24 (super.root.size), 1,
+					 strtok (filename, "/"));
+
+		if (offset <= 0)
+			return offset;
+
+		/* Resolving was successful. Examine the inode */
+		inode = (struct cramfs_inode *) (info->offset + offset);
+		if (!S_ISDIR (CRAMFS_16 (inode->mode))) {
+			/* It's not a directory - list it, and that's that */
+			return (cramfs_list_inode (info, offset) > 0);
+		}
+
+		/* It's a directory. List files within */
+		offset = CRAMFS_GET_OFFSET (inode) << 2;
+		size = CRAMFS_24 (inode->size);
+	}
+
+	/* List the given directory */
+	while (inodeoffset < size) {
+		inode = (struct cramfs_inode *) (info->offset + offset +
+						 inodeoffset);
+
+		nextoffset = cramfs_list_inode (info, offset + inodeoffset);
+		if (nextoffset == 0)
+			break;
+		inodeoffset += sizeof (struct cramfs_inode) + nextoffset;
+	}
+
+	return 1;
+}
+
+int cramfs_info (struct part_info *info)
+{
+	if (cramfs_read_super (info))
+		return 0;
+
+	printf ("size: 0x%x (%u)\n", super.size, super.size);
+
+	if (super.flags != 0) {
+		printf ("flags:\n");
+		if (super.flags & CRAMFS_FLAG_FSID_VERSION_2)
+			printf ("\tFSID version 2\n");
+		if (super.flags & CRAMFS_FLAG_SORTED_DIRS)
+			printf ("\tsorted dirs\n");
+		if (super.flags & CRAMFS_FLAG_HOLES)
+			printf ("\tholes\n");
+		if (super.flags & CRAMFS_FLAG_SHIFTED_ROOT_OFFSET)
+			printf ("\tshifted root offset\n");
+	}
+
+	printf ("fsid:\n\tcrc: 0x%x\n\tedition: 0x%x\n",
+		super.fsid.crc, super.fsid.edition);
+	printf ("name: %16s\n", super.name);
+
+	return 1;
+}
+
+int cramfs_check (struct part_info *info)
+{
+	struct cramfs_super *sb = (struct cramfs_super *) info->offset;
+
+	if (sb->magic != CRAMFS_32 (CRAMFS_MAGIC)) {
+		/* check at 512 byte offset */
+		sb = (struct cramfs_super *) (info->offset + 512);
+		if (sb->magic != CRAMFS_32 (CRAMFS_MAGIC)) {
+			return 0;
+		}
+	}
+	return 1;
+}
+
+#endif /* CFG_FS_CRAMFS */