1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Parse RedBoot-style Flash Image System (FIS) tables and 4 * produce a Linux partition array to match. 5 * 6 * Copyright © 2001 Red Hat UK Limited 7 * 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 19 struct fis_image_desc { 20 unsigned char name[16]; // Null terminated name 21 u32 flash_base; // Address within FLASH of image 22 u32 mem_base; // Address in memory where it executes 23 u32 size; // Length of image 24 u32 entry_point; // Execution entry point 25 u32 data_length; // Length of actual data 26 unsigned char _pad[256 - (16 + 7 * sizeof(u32))]; 27 u32 desc_cksum; // Checksum over image descriptor 28 u32 file_cksum; // Checksum over image data 29 }; 30 31 struct fis_list { 32 struct fis_image_desc *img; 33 struct fis_list *next; 34 }; 35 36 static int directory = CONFIG_MTD_REDBOOT_DIRECTORY_BLOCK; 37 module_param(directory, int, 0); 38 39 static 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 45 static 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 if (ret) 62 return; 63 64 /* 65 * Assign the block found in the device tree to the local 66 * directory block pointer. 67 */ 68 directory = dirblock; 69 } 70 71 static int parse_redboot_partitions(struct mtd_info *master, 72 const struct mtd_partition **pparts, 73 struct mtd_part_parser_data *data) 74 { 75 int nrparts = 0; 76 struct fis_image_desc *buf; 77 struct mtd_partition *parts; 78 struct fis_list *fl = NULL, *tmp_fl; 79 int ret, i; 80 size_t retlen; 81 char *names; 82 char *nullname; 83 int namelen = 0; 84 int nulllen = 0; 85 int numslots; 86 unsigned long offset; 87 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED 88 static char nullstring[] = "unallocated"; 89 #endif 90 91 parse_redboot_of(master); 92 93 if (directory < 0) { 94 offset = master->size + directory * master->erasesize; 95 while (mtd_block_isbad(master, offset)) { 96 if (!offset) { 97 nogood: 98 pr_notice("Failed to find a non-bad block to check for RedBoot partition table\n"); 99 return -EIO; 100 } 101 offset -= master->erasesize; 102 } 103 } else { 104 offset = directory * master->erasesize; 105 while (mtd_block_isbad(master, offset)) { 106 offset += master->erasesize; 107 if (offset == master->size) 108 goto nogood; 109 } 110 } 111 buf = vmalloc(master->erasesize); 112 113 if (!buf) 114 return -ENOMEM; 115 116 pr_notice("Searching for RedBoot partition table in %s at offset 0x%lx\n", 117 master->name, offset); 118 119 ret = mtd_read(master, offset, master->erasesize, &retlen, 120 (void *)buf); 121 122 if (ret) 123 goto out; 124 125 if (retlen != master->erasesize) { 126 ret = -EIO; 127 goto out; 128 } 129 130 numslots = (master->erasesize / sizeof(struct fis_image_desc)); 131 for (i = 0; i < numslots; i++) { 132 if (!memcmp(buf[i].name, "FIS directory", 14)) { 133 /* This is apparently the FIS directory entry for the 134 * FIS directory itself. The FIS directory size is 135 * one erase block; if the buf[i].size field is 136 * swab32(erasesize) then we know we are looking at 137 * a byte swapped FIS directory - swap all the entries! 138 * (NOTE: this is 'size' not 'data_length'; size is 139 * the full size of the entry.) 140 */ 141 142 /* RedBoot can combine the FIS directory and 143 config partitions into a single eraseblock; 144 we assume wrong-endian if either the swapped 145 'size' matches the eraseblock size precisely, 146 or if the swapped size actually fits in an 147 eraseblock while the unswapped size doesn't. */ 148 if (swab32(buf[i].size) == master->erasesize || 149 (buf[i].size > master->erasesize 150 && swab32(buf[i].size) < master->erasesize)) { 151 int j; 152 /* Update numslots based on actual FIS directory size */ 153 numslots = swab32(buf[i].size) / sizeof(struct fis_image_desc); 154 for (j = 0; j < numslots; ++j) { 155 /* A single 0xff denotes a deleted entry. 156 * Two of them in a row is the end of the table. 157 */ 158 if (buf[j].name[0] == 0xff) { 159 if (buf[j].name[1] == 0xff) { 160 break; 161 } else { 162 continue; 163 } 164 } 165 166 /* The unsigned long fields were written with the 167 * wrong byte sex, name and pad have no byte sex. 168 */ 169 swab32s(&buf[j].flash_base); 170 swab32s(&buf[j].mem_base); 171 swab32s(&buf[j].size); 172 swab32s(&buf[j].entry_point); 173 swab32s(&buf[j].data_length); 174 swab32s(&buf[j].desc_cksum); 175 swab32s(&buf[j].file_cksum); 176 } 177 } else if (buf[i].size < master->erasesize) { 178 /* Update numslots based on actual FIS directory size */ 179 numslots = buf[i].size / sizeof(struct fis_image_desc); 180 } 181 break; 182 } 183 } 184 if (i == numslots) { 185 /* Didn't find it */ 186 pr_notice("No RedBoot partition table detected in %s\n", 187 master->name); 188 ret = 0; 189 goto out; 190 } 191 192 for (i = 0; i < numslots; i++) { 193 struct fis_list *new_fl, **prev; 194 195 if (buf[i].name[0] == 0xff) { 196 if (buf[i].name[1] == 0xff) { 197 break; 198 } else { 199 continue; 200 } 201 } 202 if (!redboot_checksum(&buf[i])) 203 break; 204 205 new_fl = kmalloc(sizeof(struct fis_list), GFP_KERNEL); 206 namelen += strlen(buf[i].name) + 1; 207 if (!new_fl) { 208 ret = -ENOMEM; 209 goto out; 210 } 211 new_fl->img = &buf[i]; 212 if (data && data->origin) 213 buf[i].flash_base -= data->origin; 214 else 215 buf[i].flash_base &= master->size - 1; 216 217 /* I'm sure the JFFS2 code has done me permanent damage. 218 * I now think the following is _normal_ 219 */ 220 prev = &fl; 221 while (*prev && (*prev)->img->flash_base < new_fl->img->flash_base) 222 prev = &(*prev)->next; 223 new_fl->next = *prev; 224 *prev = new_fl; 225 226 nrparts++; 227 } 228 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED 229 if (fl->img->flash_base) { 230 nrparts++; 231 nulllen = sizeof(nullstring); 232 } 233 234 for (tmp_fl = fl; tmp_fl->next; tmp_fl = tmp_fl->next) { 235 if (tmp_fl->img->flash_base + tmp_fl->img->size + master->erasesize <= tmp_fl->next->img->flash_base) { 236 nrparts++; 237 nulllen = sizeof(nullstring); 238 } 239 } 240 #endif 241 parts = kzalloc(sizeof(*parts) * nrparts + nulllen + namelen, GFP_KERNEL); 242 243 if (!parts) { 244 ret = -ENOMEM; 245 goto out; 246 } 247 248 nullname = (char *)&parts[nrparts]; 249 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED 250 if (nulllen > 0) 251 strcpy(nullname, nullstring); 252 #endif 253 names = nullname + nulllen; 254 255 i = 0; 256 257 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED 258 if (fl->img->flash_base) { 259 parts[0].name = nullname; 260 parts[0].size = fl->img->flash_base; 261 parts[0].offset = 0; 262 i++; 263 } 264 #endif 265 for ( ; i < nrparts; i++) { 266 parts[i].size = fl->img->size; 267 parts[i].offset = fl->img->flash_base; 268 parts[i].name = names; 269 270 strcpy(names, fl->img->name); 271 #ifdef CONFIG_MTD_REDBOOT_PARTS_READONLY 272 if (!memcmp(names, "RedBoot", 8) || 273 !memcmp(names, "RedBoot config", 15) || 274 !memcmp(names, "FIS directory", 14)) { 275 parts[i].mask_flags = MTD_WRITEABLE; 276 } 277 #endif 278 names += strlen(names) + 1; 279 280 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED 281 if (fl->next && fl->img->flash_base + fl->img->size + master->erasesize <= fl->next->img->flash_base) { 282 i++; 283 parts[i].offset = parts[i - 1].size + parts[i - 1].offset; 284 parts[i].size = fl->next->img->flash_base - parts[i].offset; 285 parts[i].name = nullname; 286 } 287 #endif 288 tmp_fl = fl; 289 fl = fl->next; 290 kfree(tmp_fl); 291 } 292 ret = nrparts; 293 *pparts = parts; 294 out: 295 while (fl) { 296 struct fis_list *old = fl; 297 298 fl = fl->next; 299 kfree(old); 300 } 301 vfree(buf); 302 return ret; 303 } 304 305 static const struct of_device_id mtd_parser_redboot_of_match_table[] = { 306 { .compatible = "redboot-fis" }, 307 {}, 308 }; 309 MODULE_DEVICE_TABLE(of, mtd_parser_redboot_of_match_table); 310 311 static struct mtd_part_parser redboot_parser = { 312 .parse_fn = parse_redboot_partitions, 313 .name = "RedBoot", 314 .of_match_table = mtd_parser_redboot_of_match_table, 315 }; 316 module_mtd_part_parser(redboot_parser); 317 318 /* mtd parsers will request the module by parser name */ 319 MODULE_ALIAS("RedBoot"); 320 MODULE_LICENSE("GPL"); 321 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); 322 MODULE_DESCRIPTION("Parsing code for RedBoot Flash Image System (FIS) tables"); 323