4 * Copyright (C) 1999 Linus Torvalds
6 * Copyright (C) 2000-2002 Transmeta Corporation
8 * Copyright (C) 2003 Kai-Uwe Bloem,
9 * Auerswald GmbH & Co KG, <linux-development@auerswald.de>
10 * - adapted from the www.tuxbox.org u-boot tree, added "ls" command
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License (Version 2) as
14 * published by the Free Software Foundation.
16 * Compressed ROM filesystem for Linux.
19 * add support for resolving symbolic links
23 * These are the VFS interfaces to the compressed ROM filesystem.
24 * The actual compression is based on zlib, see the other files.
30 #if (CONFIG_COMMANDS & CFG_CMD_JFFS2)
32 #include <asm/byteorder.h>
33 #include <linux/stat.h>
34 #include <jffs2/jffs2.h>
35 #include <jffs2/load_kernel.h>
36 #include <cramfs/cramfs_fs.h>
38 /* These two macros may change in future, to provide better st_ino
40 #define CRAMINO(x) (CRAMFS_GET_OFFSET(x) ? CRAMFS_GET_OFFSET(x)<<2 : 1)
41 #define OFFSET(x) ((x)->i_ino)
43 struct cramfs_super super;
45 static int cramfs_read_super (struct part_info *info)
47 unsigned long root_offset;
49 /* Read the first block and get the superblock from it */
50 memcpy (&super, (void *) info->offset, sizeof (super));
52 /* Do sanity checks on the superblock */
53 if (super.magic != CRAMFS_32 (CRAMFS_MAGIC)) {
54 /* check at 512 byte offset */
55 memcpy (&super, (void *) info->offset + 512, sizeof (super));
56 if (super.magic != CRAMFS_32 (CRAMFS_MAGIC)) {
57 printf ("cramfs: wrong magic\n");
62 /* flags is reused several times, so swab it once */
63 super.flags = CRAMFS_32 (super.flags);
64 super.size = CRAMFS_32 (super.size);
66 /* get feature flags first */
67 if (super.flags & ~CRAMFS_SUPPORTED_FLAGS) {
68 printf ("cramfs: unsupported filesystem features\n");
72 /* Check that the root inode is in a sane state */
73 if (!S_ISDIR (CRAMFS_16 (super.root.mode))) {
74 printf ("cramfs: root is not a directory\n");
77 root_offset = CRAMFS_GET_OFFSET (&(super.root)) << 2;
78 if (root_offset == 0) {
79 printf ("cramfs: empty filesystem");
80 } else if (!(super.flags & CRAMFS_FLAG_SHIFTED_ROOT_OFFSET) &&
81 ((root_offset != sizeof (struct cramfs_super)) &&
82 (root_offset != 512 + sizeof (struct cramfs_super)))) {
83 printf ("cramfs: bad root offset %lu\n", root_offset);
90 static unsigned long cramfs_resolve (char *begin, unsigned long offset,
91 unsigned long size, int raw,
94 unsigned long inodeoffset = 0, nextoffset;
96 while (inodeoffset < size) {
97 struct cramfs_inode *inode;
101 inode = (struct cramfs_inode *) (begin + offset +
105 * Namelengths on disk are shifted by two
106 * and the name padded out to 4-byte boundaries
109 namelen = CRAMFS_GET_NAMELEN (inode) << 2;
110 name = (char *) inode + sizeof (struct cramfs_inode);
113 inodeoffset + sizeof (struct cramfs_inode) + namelen;
118 if (name[namelen - 1])
123 if (!strncmp (filename, name, namelen)) {
124 char *p = strtok (NULL, "/");
126 if (raw && (p == NULL || *p == '\0'))
127 return offset + inodeoffset;
129 if (S_ISDIR (CRAMFS_16 (inode->mode))) {
130 return cramfs_resolve (begin,
136 } else if (S_ISREG (CRAMFS_16 (inode->mode))) {
137 return offset + inodeoffset;
139 printf ("%*.*s: unsupported file type (%x)\n",
140 namelen, namelen, name,
141 CRAMFS_16 (inode->mode));
146 inodeoffset = nextoffset;
149 printf ("can't find corresponding entry\n");
153 static int cramfs_uncompress (char *begin, unsigned long offset,
154 unsigned long loadoffset)
156 struct cramfs_inode *inode = (struct cramfs_inode *) (begin + offset);
157 unsigned long *block_ptrs = (unsigned long *)
158 (begin + (CRAMFS_GET_OFFSET (inode) << 2));
159 unsigned long curr_block = (CRAMFS_GET_OFFSET (inode) +
160 (((CRAMFS_24 (inode->size)) +
162 int size, total_size = 0;
165 cramfs_uncompress_init ();
167 for (i = 0; i < ((CRAMFS_24 (inode->size) + 4095) >> 12); i++) {
168 size = cramfs_uncompress_block ((void *) loadoffset,
169 (void *) (begin + curr_block),
170 (CRAMFS_32 (block_ptrs[i]) -
176 curr_block = CRAMFS_32 (block_ptrs[i]);
179 cramfs_uncompress_exit ();
183 int cramfs_load (char *loadoffset, struct part_info *info, char *filename)
185 unsigned long offset;
187 if (cramfs_read_super (info))
190 offset = cramfs_resolve (info->offset,
191 CRAMFS_GET_OFFSET (&(super.root)) << 2,
192 CRAMFS_24 (super.root.size), 0,
193 strtok (filename, "/"));
198 return cramfs_uncompress (info->offset, offset,
199 (unsigned long) loadoffset);
202 static int cramfs_list_inode (struct part_info *info, unsigned long offset)
204 struct cramfs_inode *inode = (struct cramfs_inode *)
205 (info->offset + offset);
207 int namelen, nextoff;
210 * Namelengths on disk are shifted by two
211 * and the name padded out to 4-byte boundaries
214 namelen = CRAMFS_GET_NAMELEN (inode) << 2;
215 name = (char *) inode + sizeof (struct cramfs_inode);
221 if (name[namelen - 1])
226 printf (" %s %8d %*.*s", mkmodestr (CRAMFS_16 (inode->mode), str),
227 CRAMFS_24 (inode->size), namelen, namelen, name);
229 if ((CRAMFS_16 (inode->mode) & S_IFMT) == S_IFLNK) {
231 * Unpack the link target, trusting in the inode's size field.
233 unsigned long size = CRAMFS_24 (inode->size);
234 char *link = malloc (size);
236 if (link != NULL && cramfs_uncompress (info->offset, offset,
237 (unsigned long) link)
239 printf (" -> %*.*s\n", (int) size, (int) size, link);
241 printf (" [Error reading link]\n");
250 int cramfs_ls (struct part_info *info, char *filename)
252 struct cramfs_inode *inode;
253 unsigned long inodeoffset = 0, nextoffset;
254 unsigned long offset, size;
256 if (cramfs_read_super (info))
259 if (strlen (filename) == 0 || !strcmp (filename, "/")) {
260 /* Root directory. Use root inode in super block */
261 offset = CRAMFS_GET_OFFSET (&(super.root)) << 2;
262 size = CRAMFS_24 (super.root.size);
264 /* Resolve the path */
265 offset = cramfs_resolve (info->offset,
266 CRAMFS_GET_OFFSET (&(super.root)) <<
267 2, CRAMFS_24 (super.root.size), 1,
268 strtok (filename, "/"));
273 /* Resolving was successful. Examine the inode */
274 inode = (struct cramfs_inode *) (info->offset + offset);
275 if (!S_ISDIR (CRAMFS_16 (inode->mode))) {
276 /* It's not a directory - list it, and that's that */
277 return (cramfs_list_inode (info, offset) > 0);
280 /* It's a directory. List files within */
281 offset = CRAMFS_GET_OFFSET (inode) << 2;
282 size = CRAMFS_24 (inode->size);
285 /* List the given directory */
286 while (inodeoffset < size) {
287 inode = (struct cramfs_inode *) (info->offset + offset +
290 nextoffset = cramfs_list_inode (info, offset + inodeoffset);
293 inodeoffset += sizeof (struct cramfs_inode) + nextoffset;
299 int cramfs_info (struct part_info *info)
301 if (cramfs_read_super (info))
304 printf ("size: 0x%x (%u)\n", super.size, super.size);
306 if (super.flags != 0) {
308 if (super.flags & CRAMFS_FLAG_FSID_VERSION_2)
309 printf ("\tFSID version 2\n");
310 if (super.flags & CRAMFS_FLAG_SORTED_DIRS)
311 printf ("\tsorted dirs\n");
312 if (super.flags & CRAMFS_FLAG_HOLES)
313 printf ("\tholes\n");
314 if (super.flags & CRAMFS_FLAG_SHIFTED_ROOT_OFFSET)
315 printf ("\tshifted root offset\n");
318 printf ("fsid:\n\tcrc: 0x%x\n\tedition: 0x%x\n",
319 super.fsid.crc, super.fsid.edition);
320 printf ("name: %16s\n", super.name);
325 int cramfs_check (struct part_info *info)
327 struct cramfs_super *sb = (struct cramfs_super *) info->offset;
329 if (sb->magic != CRAMFS_32 (CRAMFS_MAGIC)) {
330 /* check at 512 byte offset */
331 sb = (struct cramfs_super *) (info->offset + 512);
332 if (sb->magic != CRAMFS_32 (CRAMFS_MAGIC)) {
339 #endif /* CFG_FS_CRAMFS */