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- // 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 = 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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