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-rwxr-xr-xfs/cramfs/cramfs.c347
1 files changed, 347 insertions, 0 deletions
diff --git a/fs/cramfs/cramfs.c b/fs/cramfs/cramfs.c
new file mode 100755
index 0000000..48e7f63
--- /dev/null
+++ b/fs/cramfs/cramfs.c
@@ -0,0 +1,347 @@
+/*
+ * 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/jffs2.h>
+#include <jffs2/load_kernel.h>
+#include <cramfs/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;
+
+/* CPU address space offset calculation macro, struct part_info offset is
+ * device address space offset, so we need to shift it by a device start address. */
+extern flash_info_t flash_info[];
+#define PART_OFFSET(x) (x->offset + flash_info[x->dev->id->num].start[0])
+
+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 *) PART_OFFSET(info), sizeof (super));
+
+ /* Do sanity checks on the superblock */
+ if (super.magic != CRAMFS_32 (CRAMFS_MAGIC)) {
+ /* check at 512 byte offset */
+ memcpy (&super, (void *) PART_OFFSET(info) + 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 (unsigned long 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 (unsigned long 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 (PART_OFFSET(info),
+ CRAMFS_GET_OFFSET (&(super.root)) << 2,
+ CRAMFS_24 (super.root.size), 0,
+ strtok (filename, "/"));
+
+ if (offset <= 0)
+ return offset;
+
+ return cramfs_uncompress (PART_OFFSET(info), offset,
+ (unsigned long) loadoffset);
+}
+
+static int cramfs_list_inode (struct part_info *info, unsigned long offset)
+{
+ struct cramfs_inode *inode = (struct cramfs_inode *)
+ (PART_OFFSET(info) + 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 (PART_OFFSET(info), 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 (PART_OFFSET(info),
+ 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 *) (PART_OFFSET(info) + 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 *) (PART_OFFSET(info) + 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;
+
+ if (info->dev->id->type != MTD_DEV_TYPE_NOR)
+ return 0;
+
+ sb = (struct cramfs_super *) PART_OFFSET(info);
+ if (sb->magic != CRAMFS_32 (CRAMFS_MAGIC)) {
+ /* check at 512 byte offset */
+ sb = (struct cramfs_super *) (PART_OFFSET(info) + 512);
+ if (sb->magic != CRAMFS_32 (CRAMFS_MAGIC))
+ return 0;
+ }
+ return 1;
+}
+
+#endif /* CFG_FS_CRAMFS */
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