u-boot/fs/cramfs/cramfs.c

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/*
* 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>
#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. */
2005-10-11 17:09:42 +00:00
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;
}