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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Parse RedBoot-style Flash Image System (FIS) tables and4 * produce a Linux partition array to match.5 *6 * Copyright © 2001 Red Hat UK Limited7 * Copyright © 2001-2010 David Woodhouse <dwmw2@infradead.org>8 */9 10#include <linux/kernel.h>11#include <linux/slab.h>12#include <linux/init.h>13#include <linux/vmalloc.h>14#include <linux/of.h>15#include <linux/mtd/mtd.h>16#include <linux/mtd/partitions.h>17#include <linux/module.h>18 19struct fis_image_desc {20 unsigned char name[16]; // Null terminated name21 u32 flash_base; // Address within FLASH of image22 u32 mem_base; // Address in memory where it executes23 u32 size; // Length of image24 u32 entry_point; // Execution entry point25 u32 data_length; // Length of actual data26 unsigned char _pad[256 - (16 + 7 * sizeof(u32))];27 u32 desc_cksum; // Checksum over image descriptor28 u32 file_cksum; // Checksum over image data29};30 31struct fis_list {32 struct fis_image_desc *img;33 struct fis_list *next;34};35 36static int directory = CONFIG_MTD_REDBOOT_DIRECTORY_BLOCK;37module_param(directory, int, 0);38 39static inline int redboot_checksum(struct fis_image_desc *img)40{41 /* RedBoot doesn't actually write the desc_cksum field yet AFAICT */42 return 1;43}44 45static void parse_redboot_of(struct mtd_info *master)46{47 struct device_node *np;48 struct device_node *npart;49 u32 dirblock;50 int ret;51 52 np = mtd_get_of_node(master);53 if (!np)54 return;55 56 npart = of_get_child_by_name(np, "partitions");57 if (!npart)58 return;59 60 ret = of_property_read_u32(npart, "fis-index-block", &dirblock);61 of_node_put(npart);62 if (ret)63 return;64 65 /*66 * Assign the block found in the device tree to the local67 * directory block pointer.68 */69 directory = dirblock;70}71 72static int parse_redboot_partitions(struct mtd_info *master,73 const struct mtd_partition **pparts,74 struct mtd_part_parser_data *data)75{76 int nrparts = 0;77 struct fis_image_desc *buf;78 struct mtd_partition *parts;79 struct fis_list *fl = NULL, *tmp_fl;80 int ret, i;81 size_t retlen;82 char *names;83 char *nullname;84 int namelen = 0;85 int nulllen = 0;86 int numslots;87 unsigned long offset;88#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED89 static char nullstring[] = "unallocated";90#endif91 92 parse_redboot_of(master);93 94 if (directory < 0) {95 offset = master->size + directory * master->erasesize;96 while (mtd_block_isbad(master, offset)) {97 if (!offset) {98nogood:99 pr_notice("Failed to find a non-bad block to check for RedBoot partition table\n");100 return -EIO;101 }102 offset -= master->erasesize;103 }104 } else {105 offset = (unsigned long) directory * master->erasesize;106 while (mtd_block_isbad(master, offset)) {107 offset += master->erasesize;108 if (offset == master->size)109 goto nogood;110 }111 }112 buf = vmalloc(master->erasesize);113 114 if (!buf)115 return -ENOMEM;116 117 pr_notice("Searching for RedBoot partition table in %s at offset 0x%lx\n",118 master->name, offset);119 120 ret = mtd_read(master, offset, master->erasesize, &retlen,121 (void *)buf);122 123 if (ret)124 goto out;125 126 if (retlen != master->erasesize) {127 ret = -EIO;128 goto out;129 }130 131 numslots = (master->erasesize / sizeof(struct fis_image_desc));132 for (i = 0; i < numslots; i++) {133 if (!memcmp(buf[i].name, "FIS directory", 14)) {134 /* This is apparently the FIS directory entry for the135 * FIS directory itself. The FIS directory size is136 * one erase block; if the buf[i].size field is137 * swab32(erasesize) then we know we are looking at138 * a byte swapped FIS directory - swap all the entries!139 * (NOTE: this is 'size' not 'data_length'; size is140 * the full size of the entry.)141 */142 143 /* RedBoot can combine the FIS directory and144 config partitions into a single eraseblock;145 we assume wrong-endian if either the swapped146 'size' matches the eraseblock size precisely,147 or if the swapped size actually fits in an148 eraseblock while the unswapped size doesn't. */149 if (swab32(buf[i].size) == master->erasesize ||150 (buf[i].size > master->erasesize151 && swab32(buf[i].size) < master->erasesize)) {152 int j;153 /* Update numslots based on actual FIS directory size */154 numslots = swab32(buf[i].size) / sizeof(struct fis_image_desc);155 for (j = 0; j < numslots; ++j) {156 /* A single 0xff denotes a deleted entry.157 * Two of them in a row is the end of the table.158 */159 if (buf[j].name[0] == 0xff) {160 if (buf[j].name[1] == 0xff) {161 break;162 } else {163 continue;164 }165 }166 167 /* The unsigned long fields were written with the168 * wrong byte sex, name and pad have no byte sex.169 */170 swab32s(&buf[j].flash_base);171 swab32s(&buf[j].mem_base);172 swab32s(&buf[j].size);173 swab32s(&buf[j].entry_point);174 swab32s(&buf[j].data_length);175 swab32s(&buf[j].desc_cksum);176 swab32s(&buf[j].file_cksum);177 }178 } else if (buf[i].size < master->erasesize) {179 /* Update numslots based on actual FIS directory size */180 numslots = buf[i].size / sizeof(struct fis_image_desc);181 }182 break;183 }184 }185 if (i == numslots) {186 /* Didn't find it */187 pr_notice("No RedBoot partition table detected in %s\n",188 master->name);189 ret = 0;190 goto out;191 }192 193 for (i = 0; i < numslots; i++) {194 struct fis_list *new_fl, **prev;195 196 if (buf[i].name[0] == 0xff) {197 if (buf[i].name[1] == 0xff) {198 break;199 } else {200 continue;201 }202 }203 if (!redboot_checksum(&buf[i]))204 break;205 206 new_fl = kmalloc(sizeof(struct fis_list), GFP_KERNEL);207 namelen += strlen(buf[i].name) + 1;208 if (!new_fl) {209 ret = -ENOMEM;210 goto out;211 }212 new_fl->img = &buf[i];213 if (data && data->origin)214 buf[i].flash_base -= data->origin;215 else216 buf[i].flash_base &= master->size - 1;217 218 /* I'm sure the JFFS2 code has done me permanent damage.219 * I now think the following is _normal_220 */221 prev = &fl;222 while (*prev && (*prev)->img->flash_base < new_fl->img->flash_base)223 prev = &(*prev)->next;224 new_fl->next = *prev;225 *prev = new_fl;226 227 nrparts++;228 }229#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED230 if (fl->img->flash_base) {231 nrparts++;232 nulllen = sizeof(nullstring);233 }234 235 for (tmp_fl = fl; tmp_fl->next; tmp_fl = tmp_fl->next) {236 if (tmp_fl->img->flash_base + tmp_fl->img->size + master->erasesize <= tmp_fl->next->img->flash_base) {237 nrparts++;238 nulllen = sizeof(nullstring);239 }240 }241#endif242 parts = kzalloc(sizeof(*parts) * nrparts + nulllen + namelen, GFP_KERNEL);243 244 if (!parts) {245 ret = -ENOMEM;246 goto out;247 }248 249 nullname = (char *)&parts[nrparts];250#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED251 if (nulllen > 0)252 strcpy(nullname, nullstring);253#endif254 names = nullname + nulllen;255 256 i = 0;257 258#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED259 if (fl->img->flash_base) {260 parts[0].name = nullname;261 parts[0].size = fl->img->flash_base;262 parts[0].offset = 0;263 i++;264 }265#endif266 for ( ; i < nrparts; i++) {267 parts[i].size = fl->img->size;268 parts[i].offset = fl->img->flash_base;269 parts[i].name = names;270 271 strcpy(names, fl->img->name);272#ifdef CONFIG_MTD_REDBOOT_PARTS_READONLY273 if (!memcmp(names, "RedBoot", 8) ||274 !memcmp(names, "RedBoot config", 15) ||275 !memcmp(names, "FIS directory", 14)) {276 parts[i].mask_flags = MTD_WRITEABLE;277 }278#endif279 names += strlen(names) + 1;280 281#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED282 if (fl->next && fl->img->flash_base + fl->img->size + master->erasesize <= fl->next->img->flash_base) {283 i++;284 parts[i].offset = parts[i - 1].size + parts[i - 1].offset;285 parts[i].size = fl->next->img->flash_base - parts[i].offset;286 parts[i].name = nullname;287 }288#endif289 tmp_fl = fl;290 fl = fl->next;291 kfree(tmp_fl);292 }293 ret = nrparts;294 *pparts = parts;295 out:296 while (fl) {297 struct fis_list *old = fl;298 299 fl = fl->next;300 kfree(old);301 }302 vfree(buf);303 return ret;304}305 306static const struct of_device_id mtd_parser_redboot_of_match_table[] = {307 { .compatible = "redboot-fis" },308 {},309};310MODULE_DEVICE_TABLE(of, mtd_parser_redboot_of_match_table);311 312static struct mtd_part_parser redboot_parser = {313 .parse_fn = parse_redboot_partitions,314 .name = "RedBoot",315 .of_match_table = mtd_parser_redboot_of_match_table,316};317module_mtd_part_parser(redboot_parser);318 319/* mtd parsers will request the module by parser name */320MODULE_ALIAS("RedBoot");321MODULE_LICENSE("GPL");322MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");323MODULE_DESCRIPTION("Parsing code for RedBoot Flash Image System (FIS) tables");324