/*
* Parse RedBoot-style Flash Image System (FIS) tables and
* produce a Linux partition array to match.
*
* Copyright © 2001 Red Hat UK Limited
* Copyright © 2001-2010 David Woodhouse <dwmw2@infradead.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/vmalloc.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
struct fis_image_desc {
unsigned char name[16]; // Null terminated name
uint32_t flash_base; // Address within FLASH of image
uint32_t mem_base; // Address in memory where it executes
uint32_t size; // Length of image
uint32_t entry_point; // Execution entry point
uint32_t data_length; // Length of actual data
unsigned char _pad[256-(16+7*sizeof(uint32_t))];
uint32_t desc_cksum; // Checksum over image descriptor
uint32_t file_cksum; // Checksum over image data
};
struct fis_list {
struct fis_image_desc *img;
struct fis_list *next;
};
static int directory = CONFIG_MTD_REDBOOT_DIRECTORY_BLOCK;
module_param(directory, int, 0);
static inline int redboot_checksum(struct fis_image_desc *img)
{
/* RedBoot doesn't actually write the desc_cksum field yet AFAICT */
return 1;
}
static int parse_redboot_partitions(struct mtd_info *master,
struct mtd_partition **pparts,
unsigned long fis_origin)
{
int nrparts = 0;
struct fis_image_desc *buf;
struct mtd_partition *parts;
struct fis_list *fl = NULL, *tmp_fl;
int ret, i;
size_t retlen;
char *names;
char *nullname;
int namelen = 0;
int nulllen = 0;
int numslots;
unsigned long offset;
#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
static char nullstring[] = "unallocated";
#endif
if ( directory < 0 ) {
offset = master->size + directory * master->erasesize;
while (master->block_isbad &&
master->block_isbad(master, offset)) {
if (!offset) {
nogood:
printk(KERN_NOTICE "Failed to find a non-bad block to check for RedBoot partition table\n");
return -EIO;
}
offset -= master->erasesize;
}
} else {
offset = directory * master->erasesize;
while (master->block_isbad &&
master->block_isbad(master, offset)) {
offset += master->erasesize;
if (offset == master->size)
goto nogood;
}
}
buf = vmalloc(master->erasesize);
if (!buf)
return -ENOMEM;
printk(KERN_NOTICE "Searching for RedBoot partition table in %s at offset 0x%lx\n",
master->name, offset);
ret = master->read(master, offset,
master->erasesize, &retlen, (void *)buf);
if (ret)
goto out;
if (retlen != master->erasesize) {
ret = -EIO;
goto out;
}
numslots = (master->erasesize / sizeof(struct fis_image_desc));
for (i = 0; i < numslots; i++) {
if (!memcmp(buf[i].name, "FIS directory", 14)) {
/* This is apparently the FIS directory entry for the
* FIS directory itself. The FIS directory size is
* one erase block; if the buf[i].size field is
* swab32(erasesize) then we know we are looking at
* a byte swapped FIS directory - swap all the entries!
* (NOTE: this is 'size' not 'data_length'; size is
* the full size of the entry.)
*/
/* RedBoot can combine the FIS directory and
config partitions into a single eraseblock;
we assume wrong-endian if either the swapped
'size' matches the eraseblock size precisely,
or if the swapped size actually fits in an
eraseblock while the unswapped size doesn't. */
if (swab32(buf[i].size) == master->erasesize ||
(buf[i].size > master->erasesize
&& swab32(buf[i].size) < master->erasesize)) {
int j;
/* Update numslots based on actual FIS directory size */
numslots = swab32(buf[i].size) / sizeof (struct fis_image_desc);
for (j = 0; j < numslots; ++j) {
/* A single 0xff denotes a deleted entry.
* Two of them in a row is the end of the table.
*/
if (buf[j].name[0] == 0xff) {
if (buf[j].name[1] == 0xff) {
break;
} else {
continue;
}
}
/* The unsigned long fields were written with the
* wrong byte sex, name and pad have no byte sex.
*/
swab32s(&buf[j].flash_base);
swab32s(&buf[j].mem_base);
swab32s(&buf[j].size);
swab32s(&buf[j].entry_point);
swab32s(&buf[j].data_length);
swab32s(&buf[j].desc_cksum);
swab32s(&buf[j].file_cksum);
}
} else if (buf[i].size < master->erasesize) {
/* Update numslots based on actual FIS directory size */
numslots = buf[i].size / sizeof(struct fis_image_desc);
}
break;
}
}
if (i == numslots) {
/* Didn't find it */
printk(KERN_NOTICE "No RedBoot partition table detected in %s\n",
master->name);
ret = 0;
goto out;
}
for (i = 0; i < numslots; i++) {
struct fis_list *new_fl, **prev;
if (buf[i].name[0] == 0xff) {
if (buf[i].name[1] == 0xff) {
break;
} else {
continue;
}
}
if (!redboot_checksum(&buf[i]))
break;
new_fl = kmalloc(sizeof(struct fis_list), GFP_KERNEL);
namelen += strlen(buf[i].name)+1;
if (!new_fl) {
ret = -ENOMEM;
goto out;
}
new_fl->img = &buf[i];
if (fis_origin) {
buf[i].flash_base -= fis_origin;
} else {
buf[i].flash_base &= master->size-1;
}
/* I'm sure the JFFS2 code has done me permanent damage.
* I now think the following is _normal_
*/
prev = &fl;
while(*prev && (*prev)->img->flash_base < new_fl->img->flash_base)
prev = &(*prev)->next;
new_fl->next = *prev;
*prev = new_fl;
nrparts++;
}
#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
if (fl->img->flash_base) {
nrparts++;
nulllen = sizeof(nullstring);
}
for (tmp_fl = fl; tmp_fl->next; tmp_fl = tmp_fl->next) {
if (tmp_fl->img->flash_base + tmp_fl->img->size + master->erasesize <= tmp_fl->next->img->flash_base) {
nrparts++;
nulllen = sizeof(nullstring);
}
}
#endif
parts = kzalloc(sizeof(*parts)*nrparts + nulllen + namelen, GFP_KERNEL);
if (!parts) {
ret = -ENOMEM;
goto out;
}
nullname = (char *)&parts[nrparts];
#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
if (nulllen > 0) {
strcpy(nullname, nullstring);
}
#endif
names = nullname + nulllen;
i=0;
#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
if (fl->img->flash_base) {
parts[0].name = nullname;
parts[0].size = fl->img->flash_base;
parts[0].offset = 0;
i++;
}
#endif
for ( ; i<nrparts; i++) {
parts[i].size = fl->img->size;
parts[i].offset = fl->img->flash_base;
parts[i].name = names;
strcpy(names, fl->img->name);
#ifdef CONFIG_MTD_REDBOOT_PARTS_READONLY
if (!memcmp(names, "RedBoot", 8) ||
!memcmp(names, "RedBoot config", 15) ||
!memcmp(names, "FIS directory", 14)) {
parts[i].mask_flags = MTD_WRITEABLE;
}
#endif
names += strlen(names)+1;
#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
if(fl->next && fl->img->flash_base + fl->img->size + master->erasesize <= fl->next->img->flash_base) {
i++;
parts[i].offset = parts[i-1].size + parts[i-1].offset;
parts[i].size = fl->next->img->flash_base - parts[i].offset;
parts[i].name = nullname;
}
#endif
tmp_fl = fl;
fl = fl->next;
kfree(tmp_fl);
}
ret = nrparts;
*pparts = parts;
out:
while (fl) {
struct fis_list *old = fl;
fl = fl->next;
kfree(old);
}
vfree(buf);
return ret;
}
static struct mtd_part_parser redboot_parser = {
.owner = THIS_MODULE,
.parse_fn = parse_redboot_partitions,
.name = "RedBoot",
};
static int __init redboot_parser_init(void)
{
return register_mtd_parser(&redboot_parser);
}
static void __exit redboot_parser_exit(void)
{
deregister_mtd_parser(&redboot_parser);
}
module_init(redboot_parser_init);
module_exit(redboot_parser_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_DESCRIPTION("Parsing code for RedBoot Flash Image System (FIS) tables");