1 /* 2 * Parse RedBoot-style Flash Image System (FIS) tables and 3 * produce a Linux partition array to match. 4 * 5 * Copyright © 2001 Red Hat UK Limited 6 * Copyright © 2001-2010 David Woodhouse <dwmw2@infradead.org> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 21 * 22 */ 23 24 #include <linux/kernel.h> 25 #include <linux/slab.h> 26 #include <linux/init.h> 27 #include <linux/vmalloc.h> 28 #include <linux/of.h> 29 #include <linux/mtd/mtd.h> 30 #include <linux/mtd/partitions.h> 31 #include <linux/module.h> 32 33 struct fis_image_desc { 34 unsigned char name[16]; // Null terminated name 35 uint32_t flash_base; // Address within FLASH of image 36 uint32_t mem_base; // Address in memory where it executes 37 uint32_t size; // Length of image 38 uint32_t entry_point; // Execution entry point 39 uint32_t data_length; // Length of actual data 40 unsigned char _pad[256-(16+7*sizeof(uint32_t))]; 41 uint32_t desc_cksum; // Checksum over image descriptor 42 uint32_t file_cksum; // Checksum over image data 43 }; 44 45 struct fis_list { 46 struct fis_image_desc *img; 47 struct fis_list *next; 48 }; 49 50 static int directory = CONFIG_MTD_REDBOOT_DIRECTORY_BLOCK; 51 module_param(directory, int, 0); 52 53 static inline int redboot_checksum(struct fis_image_desc *img) 54 { 55 /* RedBoot doesn't actually write the desc_cksum field yet AFAICT */ 56 return 1; 57 } 58 59 static void parse_redboot_of(struct mtd_info *master) 60 { 61 struct device_node *np; 62 u32 dirblock; 63 int ret; 64 65 np = mtd_get_of_node(master); 66 if (!np) 67 return; 68 69 ret = of_property_read_u32(np, "fis-index-block", &dirblock); 70 if (ret) 71 return; 72 73 /* 74 * Assign the block found in the device tree to the local 75 * directory block pointer. 76 */ 77 directory = dirblock; 78 } 79 80 static int parse_redboot_partitions(struct mtd_info *master, 81 const struct mtd_partition **pparts, 82 struct mtd_part_parser_data *data) 83 { 84 int nrparts = 0; 85 struct fis_image_desc *buf; 86 struct mtd_partition *parts; 87 struct fis_list *fl = NULL, *tmp_fl; 88 int ret, i; 89 size_t retlen; 90 char *names; 91 char *nullname; 92 int namelen = 0; 93 int nulllen = 0; 94 int numslots; 95 unsigned long offset; 96 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED 97 static char nullstring[] = "unallocated"; 98 #endif 99 100 parse_redboot_of(master); 101 102 if ( directory < 0 ) { 103 offset = master->size + directory * master->erasesize; 104 while (mtd_block_isbad(master, offset)) { 105 if (!offset) { 106 nogood: 107 printk(KERN_NOTICE "Failed to find a non-bad block to check for RedBoot partition table\n"); 108 return -EIO; 109 } 110 offset -= master->erasesize; 111 } 112 } else { 113 offset = directory * master->erasesize; 114 while (mtd_block_isbad(master, offset)) { 115 offset += master->erasesize; 116 if (offset == master->size) 117 goto nogood; 118 } 119 } 120 buf = vmalloc(master->erasesize); 121 122 if (!buf) 123 return -ENOMEM; 124 125 printk(KERN_NOTICE "Searching for RedBoot partition table in %s at offset 0x%lx\n", 126 master->name, offset); 127 128 ret = mtd_read(master, offset, master->erasesize, &retlen, 129 (void *)buf); 130 131 if (ret) 132 goto out; 133 134 if (retlen != master->erasesize) { 135 ret = -EIO; 136 goto out; 137 } 138 139 numslots = (master->erasesize / sizeof(struct fis_image_desc)); 140 for (i = 0; i < numslots; i++) { 141 if (!memcmp(buf[i].name, "FIS directory", 14)) { 142 /* This is apparently the FIS directory entry for the 143 * FIS directory itself. The FIS directory size is 144 * one erase block; if the buf[i].size field is 145 * swab32(erasesize) then we know we are looking at 146 * a byte swapped FIS directory - swap all the entries! 147 * (NOTE: this is 'size' not 'data_length'; size is 148 * the full size of the entry.) 149 */ 150 151 /* RedBoot can combine the FIS directory and 152 config partitions into a single eraseblock; 153 we assume wrong-endian if either the swapped 154 'size' matches the eraseblock size precisely, 155 or if the swapped size actually fits in an 156 eraseblock while the unswapped size doesn't. */ 157 if (swab32(buf[i].size) == master->erasesize || 158 (buf[i].size > master->erasesize 159 && swab32(buf[i].size) < master->erasesize)) { 160 int j; 161 /* Update numslots based on actual FIS directory size */ 162 numslots = swab32(buf[i].size) / sizeof (struct fis_image_desc); 163 for (j = 0; j < numslots; ++j) { 164 165 /* A single 0xff denotes a deleted entry. 166 * Two of them in a row is the end of the table. 167 */ 168 if (buf[j].name[0] == 0xff) { 169 if (buf[j].name[1] == 0xff) { 170 break; 171 } else { 172 continue; 173 } 174 } 175 176 /* The unsigned long fields were written with the 177 * wrong byte sex, name and pad have no byte sex. 178 */ 179 swab32s(&buf[j].flash_base); 180 swab32s(&buf[j].mem_base); 181 swab32s(&buf[j].size); 182 swab32s(&buf[j].entry_point); 183 swab32s(&buf[j].data_length); 184 swab32s(&buf[j].desc_cksum); 185 swab32s(&buf[j].file_cksum); 186 } 187 } else if (buf[i].size < master->erasesize) { 188 /* Update numslots based on actual FIS directory size */ 189 numslots = buf[i].size / sizeof(struct fis_image_desc); 190 } 191 break; 192 } 193 } 194 if (i == numslots) { 195 /* Didn't find it */ 196 printk(KERN_NOTICE "No RedBoot partition table detected in %s\n", 197 master->name); 198 ret = 0; 199 goto out; 200 } 201 202 for (i = 0; i < numslots; i++) { 203 struct fis_list *new_fl, **prev; 204 205 if (buf[i].name[0] == 0xff) { 206 if (buf[i].name[1] == 0xff) { 207 break; 208 } else { 209 continue; 210 } 211 } 212 if (!redboot_checksum(&buf[i])) 213 break; 214 215 new_fl = kmalloc(sizeof(struct fis_list), GFP_KERNEL); 216 namelen += strlen(buf[i].name)+1; 217 if (!new_fl) { 218 ret = -ENOMEM; 219 goto out; 220 } 221 new_fl->img = &buf[i]; 222 if (data && data->origin) 223 buf[i].flash_base -= data->origin; 224 else 225 buf[i].flash_base &= master->size-1; 226 227 /* I'm sure the JFFS2 code has done me permanent damage. 228 * I now think the following is _normal_ 229 */ 230 prev = &fl; 231 while(*prev && (*prev)->img->flash_base < new_fl->img->flash_base) 232 prev = &(*prev)->next; 233 new_fl->next = *prev; 234 *prev = new_fl; 235 236 nrparts++; 237 } 238 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED 239 if (fl->img->flash_base) { 240 nrparts++; 241 nulllen = sizeof(nullstring); 242 } 243 244 for (tmp_fl = fl; tmp_fl->next; tmp_fl = tmp_fl->next) { 245 if (tmp_fl->img->flash_base + tmp_fl->img->size + master->erasesize <= tmp_fl->next->img->flash_base) { 246 nrparts++; 247 nulllen = sizeof(nullstring); 248 } 249 } 250 #endif 251 parts = kzalloc(sizeof(*parts)*nrparts + nulllen + namelen, GFP_KERNEL); 252 253 if (!parts) { 254 ret = -ENOMEM; 255 goto out; 256 } 257 258 nullname = (char *)&parts[nrparts]; 259 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED 260 if (nulllen > 0) { 261 strcpy(nullname, nullstring); 262 } 263 #endif 264 names = nullname + nulllen; 265 266 i=0; 267 268 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED 269 if (fl->img->flash_base) { 270 parts[0].name = nullname; 271 parts[0].size = fl->img->flash_base; 272 parts[0].offset = 0; 273 i++; 274 } 275 #endif 276 for ( ; i<nrparts; i++) { 277 parts[i].size = fl->img->size; 278 parts[i].offset = fl->img->flash_base; 279 parts[i].name = names; 280 281 strcpy(names, fl->img->name); 282 #ifdef CONFIG_MTD_REDBOOT_PARTS_READONLY 283 if (!memcmp(names, "RedBoot", 8) || 284 !memcmp(names, "RedBoot config", 15) || 285 !memcmp(names, "FIS directory", 14)) { 286 parts[i].mask_flags = MTD_WRITEABLE; 287 } 288 #endif 289 names += strlen(names)+1; 290 291 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED 292 if(fl->next && fl->img->flash_base + fl->img->size + master->erasesize <= fl->next->img->flash_base) { 293 i++; 294 parts[i].offset = parts[i-1].size + parts[i-1].offset; 295 parts[i].size = fl->next->img->flash_base - parts[i].offset; 296 parts[i].name = nullname; 297 } 298 #endif 299 tmp_fl = fl; 300 fl = fl->next; 301 kfree(tmp_fl); 302 } 303 ret = nrparts; 304 *pparts = parts; 305 out: 306 while (fl) { 307 struct fis_list *old = fl; 308 fl = fl->next; 309 kfree(old); 310 } 311 vfree(buf); 312 return ret; 313 } 314 315 static const struct of_device_id mtd_parser_redboot_of_match_table[] = { 316 { .compatible = "redboot-fis" }, 317 {}, 318 }; 319 MODULE_DEVICE_TABLE(of, mtd_parser_redboot_of_match_table); 320 321 static struct mtd_part_parser redboot_parser = { 322 .parse_fn = parse_redboot_partitions, 323 .name = "RedBoot", 324 .of_match_table = mtd_parser_redboot_of_match_table, 325 }; 326 module_mtd_part_parser(redboot_parser); 327 328 /* mtd parsers will request the module by parser name */ 329 MODULE_ALIAS("RedBoot"); 330 MODULE_LICENSE("GPL"); 331 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); 332 MODULE_DESCRIPTION("Parsing code for RedBoot Flash Image System (FIS) tables"); 333