// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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 <[email protected]>
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/vmalloc.h>
#include <linux/of.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/module.h>
struct fis_image_desc {
unsigned char name[16]; // Null terminated name
u32 flash_base; // Address within FLASH of image
u32 mem_base; // Address in memory where it executes
u32 size; // Length of image
u32 entry_point; // Execution entry point
u32 data_length; // Length of actual data
unsigned char _pad[256 - (16 + 7 * sizeof(u32))];
u32 desc_cksum; // Checksum over image descriptor
u32 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 void parse_redboot_of(struct mtd_info *master)
{
struct device_node *np;
struct device_node *npart;
u32 dirblock;
int ret;
np = mtd_get_of_node(master);
if (!np)
return;
npart = of_get_child_by_name(np, "partitions");
if (!npart)
return;
ret = of_property_read_u32(npart, "fis-index-block", &dirblock);
of_node_put(npart);
if (ret)
return;
/*
* Assign the block found in the device tree to the local
* directory block pointer.
*/
directory = dirblock;
}
static int parse_redboot_partitions(struct mtd_info *master,
const struct mtd_partition **pparts,
struct mtd_part_parser_data *data)
{
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
parse_redboot_of(master);
if (directory < 0) {
offset = master->size + directory * master->erasesize;
while (mtd_block_isbad(master, offset)) {
if (!offset) {
nogood:
pr_notice("Failed to find a non-bad block to check for RedBoot partition table\n");
return -EIO;
}
offset -= master->erasesize;
}
} else {
offset = (unsigned long) directory * master->erasesize;
while (mtd_block_isbad(master, offset)) {
offset += master->erasesize;
if (offset == master->size)
goto nogood;
}
}
buf = vmalloc(master->erasesize);
if (!buf)
return -ENOMEM;
pr_notice("Searching for RedBoot partition table in %s at offset 0x%lx\n",
master->name, offset);
ret = mtd_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 */
pr_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 (data && data->origin)
buf[i].flash_base -= data->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 const struct of_device_id mtd_parser_redboot_of_match_table[] = {
{ .compatible = "redboot-fis" },
{},
};
MODULE_DEVICE_TABLE(of, mtd_parser_redboot_of_match_table);
static struct mtd_part_parser redboot_parser = {
.parse_fn = parse_redboot_partitions,
.name = "RedBoot",
.of_match_table = mtd_parser_redboot_of_match_table,
};
module_mtd_part_parser(redboot_parser);
/* mtd parsers will request the module by parser name */
MODULE_ALIAS("RedBoot");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <[email protected]>");
MODULE_DESCRIPTION("Parsing code for RedBoot Flash Image System (FIS) tables");
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