u-boot/fs/cramfs/cramfs.c
Wolfgang Denk 700a0c648d Add common (with Linux) MTD partition scheme and "mtdparts" command
Old, obsolete and duplicated code was cleaned up and replace by the
new partitioning method. There are two possible approaches now:
* define a single, static partition
* use mtdparts command line option and dynamic partitioning
Default is static partitioning.
2005-08-08 01:03:24 +02:00

348 lines
8.9 KiB
C

/*
* 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[CFG_MAX_FLASH_BANKS];
#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 */