cmd/gpt.c

   1 /*
   2  * cmd_gpt.c -- GPT (GUID Partition Table) handling command
   3  *
   4  * Copyright (C) 2015
   5  * Lukasz Majewski <l.majewski@majess.pl>
   6  *
   7  * Copyright (C) 2012 Samsung Electronics
   8  * author: Lukasz Majewski <l.majewski@samsung.com>
   9  * author: Piotr Wilczek <p.wilczek@samsung.com>
  10  *
  11  * SPDX-License-Identifier:     GPL-2.0+
  12  */
  13
  14 #include <common.h>
  15 #include <malloc.h>
  16 #include <command.h>
  17 #include <part_efi.h>
  18 #include <exports.h>
  19 #include <linux/ctype.h>
  20 #include <div64.h>
  21 #include <memalign.h>
  22 #include <linux/compat.h>
  23 #include <linux/sizes.h>
  24 #include <stdlib.h>
  25
  26 static LIST_HEAD(disk_partitions);
  27
  28 /**
  29  * extract_env(): Expand env name from string format '&{env_name}'
  30  *                and return pointer to the env (if the env is set)
  31  *
  32  * @param str - pointer to string
  33  * @param env - pointer to pointer to extracted env
  34  *
  35  * @return - zero on successful expand and env is set
  36  */
  37 static int extract_env(const char *str, char **env)
  38 {
  39         int ret = -1;
  40         char *e, *s;
  41 #ifdef CONFIG_RANDOM_UUID
  42         char uuid_str[UUID_STR_LEN + 1];
  43 #endif
  44
  45         if (!str || strlen(str) < 4)
  46                 return -1;
  47
  48         if (!((strncmp(str, "${", 2) == 0) && (str[strlen(str) - 1] == '}')))
  49                 return -1;
  50
  51         s = strdup(str);
  52         if (s == NULL)
  53                 return -1;
  54
  55         memset(s + strlen(s) - 1, '\0', 1);
  56         memmove(s, s + 2, strlen(s) - 1);
  57
  58         e = env_get(s);
  59         if (e == NULL) {
  60 #ifdef CONFIG_RANDOM_UUID
  61                 debug("%s unset. ", str);
  62                 gen_rand_uuid_str(uuid_str, UUID_STR_FORMAT_GUID);
  63                 env_set(s, uuid_str);
  64
  65                 e = env_get(s);
  66                 if (e) {
  67                         debug("Set to random.\n");
  68                         ret = 0;
  69                 } else {
  70                         debug("Can't get random UUID.\n");
  71                 }
  72 #else
  73                 debug("%s unset.\n", str);
  74 #endif
  75         } else {
  76                 debug("%s get from environment.\n", str);
  77                 ret = 0;
  78         }
  79
  80         *env = e;
  81         free(s);
  82
  83         return ret;
  84 }
  85
  86 /**
  87  * extract_val(): Extract value from a key=value pair list (comma separated).
  88  *                Only value for the given key is returend.
  89  *                Function allocates memory for the value, remember to free!
  90  *
  91  * @param str - pointer to string with key=values pairs
  92  * @param key - pointer to the key to search for
  93  *
  94  * @return - pointer to allocated string with the value
  95  */
  96 static char *extract_val(const char *str, const char *key)
  97 {
  98         char *v, *k;
  99         char *s, *strcopy;
 100         char *new = NULL;
 101
 102         strcopy = strdup(str);
 103         if (strcopy == NULL)
 104                 return NULL;
 105
 106         s = strcopy;
 107         while (s) {
 108                 v = strsep(&s, ",");
 109                 if (!v)
 110                         break;
 111                 k = strsep(&v, "=");
 112                 if (!k)
 113                         break;
 114                 if  (strcmp(k, key) == 0) {
 115                         new = strdup(v);
 116                         break;
 117                 }
 118         }
 119
 120         free(strcopy);
 121
 122         return new;
 123 }
 124
 125 /**
 126  * found_key(): Found key without value in parameter list (comma separated).
 127  *
 128  * @param str - pointer to string with key
 129  * @param key - pointer to the key to search for
 130  *
 131  * @return - true on found key
 132  */
 133 static bool found_key(const char *str, const char *key)
 134 {
 135         char *k;
 136         char *s, *strcopy;
 137         bool result = false;
 138
 139         strcopy = strdup(str);
 140         if (!strcopy)
 141                 return NULL;
 142
 143         s = strcopy;
 144         while (s) {
 145                 k = strsep(&s, ",");
 146                 if (!k)
 147                         break;
 148                 if  (strcmp(k, key) == 0) {
 149                         result = true;
 150                         break;
 151                 }
 152         }
 153
 154         free(strcopy);
 155
 156         return result;
 157 }
 158
 159 static int calc_parts_list_len(int numparts)
 160 {
 161         int partlistlen = UUID_STR_LEN + 1 + strlen("uuid_disk=");
 162         /* for the comma */
 163         partlistlen++;
 164
 165         /* per-partition additions; numparts starts at 1, so this should be correct */
 166         partlistlen += numparts * (strlen("name=,") + PART_NAME_LEN + 1);
 167         /* see part.h for definition of struct disk_partition */
 168         partlistlen += numparts * (strlen("start=MiB,") + sizeof(lbaint_t) + 1);
 169         partlistlen += numparts * (strlen("size=MiB,") + sizeof(lbaint_t) + 1);
 170         partlistlen += numparts * (strlen("uuid=;") + UUID_STR_LEN + 1);
 171         /* for the terminating null */
 172         partlistlen++;
 173         debug("Length of partitions_list is %d for %d partitions\n", partlistlen,
 174               numparts);
 175         return partlistlen;
 176 }
 177
 178 #ifdef CONFIG_CMD_GPT_RENAME
 179 static void del_gpt_info(void)
 180 {
 181         struct list_head *pos = &disk_partitions;
 182         struct disk_part *curr;
 183         while (!list_empty(pos)) {
 184                 curr = list_entry(pos->next, struct disk_part, list);
 185                 list_del(pos->next);
 186                 free(curr);
 187         }
 188 }
 189
 190 static struct disk_part *allocate_disk_part(disk_partition_t *info, int partnum)
 191 {
 192         struct disk_part *newpart;
 193         newpart = malloc(sizeof(*newpart));
 194         if (!newpart)
 195                 return ERR_PTR(-ENOMEM);
 196         memset(newpart, '\0', sizeof(newpart));
 197
 198         newpart->gpt_part_info.start = info->start;
 199         newpart->gpt_part_info.size = info->size;
 200         newpart->gpt_part_info.blksz = info->blksz;
 201         strncpy((char *)newpart->gpt_part_info.name, (const char *)info->name,
 202                 PART_NAME_LEN);
 203         newpart->gpt_part_info.name[PART_NAME_LEN - 1] = '\0';
 204         strncpy((char *)newpart->gpt_part_info.type, (const char *)info->type,
 205                 PART_TYPE_LEN);
 206         newpart->gpt_part_info.type[PART_TYPE_LEN - 1] = '\0';
 207         newpart->gpt_part_info.bootable = info->bootable;
 208 #ifdef CONFIG_PARTITION_UUIDS
 209         strncpy(newpart->gpt_part_info.uuid, (const char *)info->uuid,
 210                 UUID_STR_LEN);
 211         /* UUID_STR_LEN is correct, as uuid[]'s length is UUID_STR_LEN+1 chars */
 212         newpart->gpt_part_info.uuid[UUID_STR_LEN] = '\0';
 213 #endif
 214         newpart->partnum = partnum;
 215
 216         return newpart;
 217 }
 218
 219 static void prettyprint_part_size(char *sizestr, lbaint_t partsize,
 220                                   lbaint_t blksize)
 221 {
 222         unsigned long long partbytes, partmegabytes;
 223
 224         partbytes = partsize * blksize;
 225         partmegabytes = lldiv(partbytes, SZ_1M);
 226         snprintf(sizestr, 16, "%lluMiB", partmegabytes);
 227 }
 228
 229 static void print_gpt_info(void)
 230 {
 231         struct list_head *pos;
 232         struct disk_part *curr;
 233         char partstartstr[16];
 234         char partsizestr[16];
 235
 236         list_for_each(pos, &disk_partitions) {
 237                 curr = list_entry(pos, struct disk_part, list);
 238                 prettyprint_part_size(partstartstr, curr->gpt_part_info.start,
 239                                       curr->gpt_part_info.blksz);
 240                 prettyprint_part_size(partsizestr, curr->gpt_part_info.size,
 241                                       curr->gpt_part_info.blksz);
 242
 243                 printf("Partition %d:\n", curr->partnum);
 244                 printf("Start %s, size %s\n", partstartstr, partsizestr);
 245                 printf("Block size %lu, name %s\n", curr->gpt_part_info.blksz,
 246                        curr->gpt_part_info.name);
 247                 printf("Type %s, bootable %d\n", curr->gpt_part_info.type,
 248                        curr->gpt_part_info.bootable);
 249 #ifdef CONFIG_PARTITION_UUIDS
 250                 printf("UUID %s\n", curr->gpt_part_info.uuid);
 251 #endif
 252                 printf("\n");
 253         }
 254 }
 255
 256 /*
 257  * create the string that upstream 'gpt write' command will accept as an
 258  * argument
 259  *
 260  * From doc/README.gpt, Format of partitions layout:
 261  *    "uuid_disk=...;name=u-boot,size=60MiB,uuid=...;
 262  *      name=kernel,size=60MiB,uuid=...;"
 263  * The fields 'name' and 'size' are mandatory for every partition.
 264  * The field 'start' is optional. The fields 'uuid' and 'uuid_disk'
 265  * are optional if CONFIG_RANDOM_UUID is enabled.
 266  */
 267 static int create_gpt_partitions_list(int numparts, const char *guid,
 268                                       char *partitions_list)
 269 {
 270         struct list_head *pos;
 271         struct disk_part *curr;
 272         char partstr[PART_NAME_LEN + 1];
 273
 274         if (!partitions_list)
 275                 return -EINVAL;
 276
 277         strcpy(partitions_list, "uuid_disk=");
 278         strncat(partitions_list, guid, UUID_STR_LEN + 1);
 279         strcat(partitions_list, ";");
 280
 281         list_for_each(pos, &disk_partitions) {
 282                 curr = list_entry(pos, struct disk_part, list);
 283                 strcat(partitions_list, "name=");
 284                 strncat(partitions_list, (const char *)curr->gpt_part_info.name,
 285                         PART_NAME_LEN + 1);
 286                 strcat(partitions_list, ",start=");
 287                 prettyprint_part_size(partstr, (unsigned long)curr->gpt_part_info.start,
 288                                       (unsigned long) curr->gpt_part_info.blksz);
 289                 /* one extra byte for NULL */
 290                 strncat(partitions_list, partstr, PART_NAME_LEN + 1);
 291                 strcat(partitions_list, ",size=");
 292                 prettyprint_part_size(partstr, curr->gpt_part_info.size,
 293                                       curr->gpt_part_info.blksz);
 294                 strncat(partitions_list, partstr, PART_NAME_LEN + 1);
 295
 296                 strcat(partitions_list, ",uuid=");
 297                 strncat(partitions_list, curr->gpt_part_info.uuid,
 298                         UUID_STR_LEN + 1);
 299                 strcat(partitions_list, ";");
 300         }
 301         return 0;
 302 }
 303
 304 /*
 305  * read partition info into disk_partitions list where
 306  * it can be printed or modified
 307  */
 308 static int get_gpt_info(struct blk_desc *dev_desc)
 309 {
 310         /* start partition numbering at 1, as U-Boot does */
 311         int valid_parts = 0, p, ret;
 312         disk_partition_t info;
 313         struct disk_part *new_disk_part;
 314
 315         /*
 316          * Always re-read partition info from device, in case
 317          * it has changed
 318          */
 319         INIT_LIST_HEAD(&disk_partitions);
 320
 321         for (p = 1; p <= MAX_SEARCH_PARTITIONS; p++) {
 322                 ret = part_get_info(dev_desc, p, &info);
 323                 if (ret)
 324                         continue;
 325
 326                 /* Add 1 here because counter is zero-based but p1 is
 327                    the first partition */
 328                 new_disk_part = allocate_disk_part(&info, valid_parts+1);
 329                 if (IS_ERR(new_disk_part))
 330                         goto out;
 331
 332                 list_add_tail(&new_disk_part->list, &disk_partitions);
 333                 valid_parts++;
 334         }
 335         if (valid_parts == 0) {
 336                 printf("** No valid partitions found **\n");
 337                 goto out;
 338         }
 339         return valid_parts;
 340  out:
 341         if (valid_parts >= 1)
 342                 del_gpt_info();
 343         return -ENODEV;
 344 }
 345
 346 /* a wrapper to test get_gpt_info */
 347 static int do_get_gpt_info(struct blk_desc *dev_desc)
 348 {
 349         int ret;
 350
 351         ret = get_gpt_info(dev_desc);
 352         if (ret > 0) {
 353                 print_gpt_info();
 354                 del_gpt_info();
 355                 return 0;
 356         }
 357         return ret;
 358 }
 359 #endif
 360
 361 /**
 362  * set_gpt_info(): Fill partition information from string
 363  *              function allocates memory, remember to free!
 364  *
 365  * @param dev_desc - pointer block device descriptor
 366  * @param str_part - pointer to string with partition information
 367  * @param str_disk_guid - pointer to pointer to allocated string with disk guid
 368  * @param partitions - pointer to pointer to allocated partitions array
 369  * @param parts_count - number of partitions
 370  *
 371  * @return - zero on success, otherwise error
 372  *
 373  */
 374 static int set_gpt_info(struct blk_desc *dev_desc,
 375                         const char *str_part,
 376                         char **str_disk_guid,
 377                         disk_partition_t **partitions,
 378                         u8 *parts_count)
 379 {
 380         char *tok, *str, *s;
 381         int i;
 382         char *val, *p;
 383         int p_count;
 384         disk_partition_t *parts;
 385         int errno = 0;
 386         uint64_t size_ll, start_ll;
 387         lbaint_t offset = 0;
 388         int max_str_part = calc_parts_list_len(MAX_SEARCH_PARTITIONS);
 389
 390         debug("%s:  lba num: 0x%x %d\n", __func__,
 391               (unsigned int)dev_desc->lba, (unsigned int)dev_desc->lba);
 392
 393         if (str_part == NULL)
 394                 return -1;
 395
 396         str = strdup(str_part);
 397         if (str == NULL)
 398                 return -ENOMEM;
 399
 400         /* extract disk guid */
 401         s = str;
 402         val = extract_val(str, "uuid_disk");
 403         if (!val) {
 404 #ifdef CONFIG_RANDOM_UUID
 405                 *str_disk_guid = malloc(UUID_STR_LEN + 1);
 406                 if (str_disk_guid == NULL)
 407                         return -ENOMEM;
 408                 gen_rand_uuid_str(*str_disk_guid, UUID_STR_FORMAT_STD);
 409 #else
 410                 free(str);
 411                 return -2;
 412 #endif
 413         } else {
 414                 val = strsep(&val, ";");
 415                 if (extract_env(val, &p))
 416                         p = val;
 417                 *str_disk_guid = strdup(p);
 418                 free(val);
 419                 /* Move s to first partition */
 420                 strsep(&s, ";");
 421         }
 422         if (s == NULL) {
 423                 printf("Error: is the partitions string NULL-terminated?\n");
 424                 return -EINVAL;
 425         }
 426         if (strnlen(s, max_str_part) == 0)
 427                 return -3;
 428
 429         i = strnlen(s, max_str_part) - 1;
 430         if (s[i] == ';')
 431                 s[i] = '\0';
 432
 433         /* calculate expected number of partitions */
 434         p_count = 1;
 435         p = s;
 436         while (*p) {
 437                 if (*p++ == ';')
 438                         p_count++;
 439         }
 440
 441         /* allocate memory for partitions */
 442         parts = calloc(sizeof(disk_partition_t), p_count);
 443         if (parts == NULL)
 444                 return -ENOMEM;
 445
 446         /* retrieve partitions data from string */
 447         for (i = 0; i < p_count; i++) {
 448                 tok = strsep(&s, ";");
 449
 450                 if (tok == NULL)
 451                         break;
 452
 453                 /* uuid */
 454                 val = extract_val(tok, "uuid");
 455                 if (!val) {
 456                         /* 'uuid' is optional if random uuid's are enabled */
 457 #ifdef CONFIG_RANDOM_UUID
 458                         gen_rand_uuid_str(parts[i].uuid, UUID_STR_FORMAT_STD);
 459 #else
 460                         errno = -4;
 461                         goto err;
 462 #endif
 463                 } else {
 464                         if (extract_env(val, &p))
 465                                 p = val;
 466                         if (strnlen(p, max_str_part) >= sizeof(parts[i].uuid)) {
 467                                 printf("Wrong uuid format for partition %d\n", i);
 468                                 errno = -4;
 469                                 goto err;
 470                         }
 471                         strncpy((char *)parts[i].uuid, p, max_str_part);
 472                         free(val);
 473                 }
 474 #ifdef CONFIG_PARTITION_TYPE_GUID
 475                 /* guid */
 476                 val = extract_val(tok, "type");
 477                 if (val) {
 478                         /* 'type' is optional */
 479                         if (extract_env(val, &p))
 480                                 p = val;
 481                         if (strnlen(p, max_str_part) >= sizeof(parts[i].type_guid)) {
 482                                 printf("Wrong type guid format for partition %d\n",
 483                                        i);
 484                                 errno = -4;
 485                                 goto err;
 486                         }
 487                         strncpy((char *)parts[i].type_guid, p, max_str_part);
 488                         free(val);
 489                 }
 490 #endif
 491                 /* name */
 492                 val = extract_val(tok, "name");
 493                 if (!val) { /* name is mandatory */
 494                         errno = -4;
 495                         goto err;
 496                 }
 497                 if (extract_env(val, &p))
 498                         p = val;
 499                 if (strnlen(p, max_str_part) >= sizeof(parts[i].name)) {
 500                         errno = -4;
 501                         goto err;
 502                 }
 503                 strncpy((char *)parts[i].name, p, max_str_part);
 504                 free(val);
 505
 506                 /* size */
 507                 val = extract_val(tok, "size");
 508                 if (!val) { /* 'size' is mandatory */
 509                         errno = -4;
 510                         goto err;
 511                 }
 512                 if (extract_env(val, &p))
 513                         p = val;
 514                 if ((strcmp(p, "-") == 0)) {
 515                         /* Let part efi module to auto extend the size */
 516                         parts[i].size = 0;
 517                 } else {
 518                         size_ll = ustrtoull(p, &p, 0);
 519                         parts[i].size = lldiv(size_ll, dev_desc->blksz);
 520                 }
 521
 522                 free(val);
 523
 524                 /* start address */
 525                 val = extract_val(tok, "start");
 526                 if (val) { /* start address is optional */
 527                         if (extract_env(val, &p))
 528                                 p = val;
 529                         start_ll = ustrtoull(p, &p, 0);
 530                         parts[i].start = lldiv(start_ll, dev_desc->blksz);
 531                         free(val);
 532                 }
 533
 534                 offset += parts[i].size + parts[i].start;
 535
 536                 /* bootable */
 537                 if (found_key(tok, "bootable"))
 538                         parts[i].bootable = 1;
 539         }
 540
 541         *parts_count = p_count;
 542         *partitions = parts;
 543         free(str);
 544
 545         return 0;
 546 err:
 547         free(str);
 548         free(*str_disk_guid);
 549         free(parts);
 550
 551         return errno;
 552 }
 553
 554 static int gpt_default(struct blk_desc *blk_dev_desc, const char *str_part)
 555 {
 556         int ret;
 557         char *str_disk_guid;
 558         u8 part_count = 0;
 559         disk_partition_t *partitions = NULL;
 560
 561         /* fill partitions */
 562         ret = set_gpt_info(blk_dev_desc, str_part,
 563                         &str_disk_guid, &partitions, &part_count);
 564         if (ret) {
 565                 if (ret == -1)
 566                         printf("No partition list provided\n");
 567                 if (ret == -2)
 568                         printf("Missing disk guid\n");
 569                 if ((ret == -3) || (ret == -4))
 570                         printf("Partition list incomplete\n");
 571                 return -1;
 572         }
 573
 574         /* save partitions layout to disk */
 575         ret = gpt_restore(blk_dev_desc, str_disk_guid, partitions, part_count);
 576         free(str_disk_guid);
 577         free(partitions);
 578
 579         return ret;
 580 }
 581
 582 static int gpt_verify(struct blk_desc *blk_dev_desc, const char *str_part)
 583 {
 584         ALLOC_CACHE_ALIGN_BUFFER_PAD(gpt_header, gpt_head, 1,
 585                                      blk_dev_desc->blksz);
 586         disk_partition_t *partitions = NULL;
 587         gpt_entry *gpt_pte = NULL;
 588         char *str_disk_guid;
 589         u8 part_count = 0;
 590         int ret = 0;
 591
 592         /* fill partitions */
 593         ret = set_gpt_info(blk_dev_desc, str_part,
 594                         &str_disk_guid, &partitions, &part_count);
 595         if (ret) {
 596                 if (ret == -1) {
 597                         printf("No partition list provided - only basic check\n");
 598                         ret = gpt_verify_headers(blk_dev_desc, gpt_head,
 599                                                  &gpt_pte);
 600                         goto out;
 601                 }
 602                 if (ret == -2)
 603                         printf("Missing disk guid\n");
 604                 if ((ret == -3) || (ret == -4))
 605                         printf("Partition list incomplete\n");
 606                 return -1;
 607         }
 608
 609         /* Check partition layout with provided pattern */
 610         ret = gpt_verify_partitions(blk_dev_desc, partitions, part_count,
 611                                     gpt_head, &gpt_pte);
 612         free(str_disk_guid);
 613         free(partitions);
 614  out:
 615         free(gpt_pte);
 616         return ret;
 617 }
 618
 619 static int do_disk_guid(struct blk_desc *dev_desc, char * const namestr)
 620 {
 621         int ret;
 622         char disk_guid[UUID_STR_LEN + 1];
 623
 624         ret = get_disk_guid(dev_desc, disk_guid);
 625         if (ret < 0)
 626                 return CMD_RET_FAILURE;
 627
 628         if (namestr)
 629                 env_set(namestr, disk_guid);
 630         else
 631                 printf("%s\n", disk_guid);
 632
 633         return ret;
 634 }
 635
 636 #ifdef CONFIG_CMD_GPT_RENAME
 637 static int do_rename_gpt_parts(struct blk_desc *dev_desc, char *subcomm,
 638                                char *name1, char *name2)
 639 {
 640         struct list_head *pos;
 641         struct disk_part *curr;
 642         disk_partition_t *new_partitions = NULL;
 643         char disk_guid[UUID_STR_LEN + 1];
 644         char *partitions_list, *str_disk_guid;
 645         u8 part_count = 0;
 646         int partlistlen, ret, numparts = 0, partnum, i = 1, ctr1 = 0, ctr2 = 0;
 647
 648         if ((subcomm == NULL) || (name1 == NULL) || (name2 == NULL) ||
 649             (strcmp(subcomm, "swap") && (strcmp(subcomm, "rename"))))
 650                 return -EINVAL;
 651
 652         ret = get_disk_guid(dev_desc, disk_guid);
 653         if (ret < 0)
 654                 return ret;
 655         numparts = get_gpt_info(dev_desc);
 656         if (numparts <=  0)
 657                 return numparts ? numparts : -ENODEV;
 658
 659         partlistlen = calc_parts_list_len(numparts);
 660         partitions_list = malloc(partlistlen);
 661         if (partitions_list == NULL)
 662                 return -ENOMEM;
 663         memset(partitions_list, '\0', partlistlen);
 664
 665         ret = create_gpt_partitions_list(numparts, disk_guid, partitions_list);
 666         if (ret < 0)
 667                 return ret;
 668         /*
 669          * Uncomment the following line to print a string that 'gpt write'
 670          * or 'gpt verify' will accept as input.
 671          */
 672         debug("OLD partitions_list is %s with %u chars\n", partitions_list,
 673               (unsigned)strlen(partitions_list));
 674
 675         ret = set_gpt_info(dev_desc, partitions_list, &str_disk_guid,
 676                            &new_partitions, &part_count);
 677         if (ret < 0)
 678                 return ret;
 679
 680         if (!strcmp(subcomm, "swap")) {
 681                 if ((strlen(name1) > PART_NAME_LEN) || (strlen(name2) > PART_NAME_LEN)) {
 682                         printf("Names longer than %d characters are truncated.\n", PART_NAME_LEN);
 683                         return -EINVAL;
 684                 }
 685                 list_for_each(pos, &disk_partitions) {
 686                         curr = list_entry(pos, struct disk_part, list);
 687                         if (!strcmp((char *)curr->gpt_part_info.name, name1)) {
 688                                 strcpy((char *)curr->gpt_part_info.name, name2);
 689                                 ctr1++;
 690                         } else if (!strcmp((char *)curr->gpt_part_info.name, name2)) {
 691                                 strcpy((char *)curr->gpt_part_info.name, name1);
 692                                 ctr2++;
 693                         }
 694                 }
 695                 if ((ctr1 + ctr2 < 2) || (ctr1 != ctr2)) {
 696                         printf("Cannot swap partition names except in pairs.\n");
 697                         return -EINVAL;
 698                 }
 699         } else { /* rename */
 700                 if (strlen(name2) > PART_NAME_LEN) {
 701                         printf("Names longer than %d characters are truncated.\n", PART_NAME_LEN);
 702                         return -EINVAL;
 703                 }
 704                 partnum = (int)simple_strtol(name1, NULL, 10);
 705                 if ((partnum < 0) || (partnum > numparts)) {
 706                         printf("Illegal partition number %s\n", name1);
 707                         return -EINVAL;
 708                 }
 709                 ret = part_get_info(dev_desc, partnum, new_partitions);
 710                 if (ret < 0)
 711                         return ret;
 712
 713                 /* U-Boot partition numbering starts at 1 */
 714                 list_for_each(pos, &disk_partitions) {
 715                         curr = list_entry(pos, struct disk_part, list);
 716                         if (i == partnum) {
 717                                 strcpy((char *)curr->gpt_part_info.name, name2);
 718                                 break;
 719                         }
 720                         i++;
 721                 }
 722         }
 723
 724         ret = create_gpt_partitions_list(numparts, disk_guid, partitions_list);
 725         if (ret < 0)
 726                 return ret;
 727         debug("NEW partitions_list is %s with %u chars\n", partitions_list,
 728               (unsigned)strlen(partitions_list));
 729
 730         ret = set_gpt_info(dev_desc, partitions_list, &str_disk_guid,
 731                            &new_partitions, &part_count);
 732         if (ret < 0)
 733                 return ret;
 734
 735         debug("Writing new partition table\n");
 736         ret = gpt_restore(dev_desc, disk_guid, new_partitions, numparts);
 737         if (ret < 0) {
 738                 printf("Writing new partition table failed\n");
 739                 return ret;
 740         }
 741
 742         debug("Reading back new partition table\n");
 743         numparts = get_gpt_info(dev_desc);
 744         if (numparts <=  0)
 745                 return numparts ? numparts : -ENODEV;
 746         printf("new partition table with %d partitions is:\n", numparts);
 747         print_gpt_info();
 748
 749         del_gpt_info();
 750         free(partitions_list);
 751         free(str_disk_guid);
 752         free(new_partitions);
 753         return ret;
 754 }
 755 #endif
 756
 757 /**
 758  * do_gpt(): Perform GPT operations
 759  *
 760  * @param cmdtp - command name
 761  * @param flag
 762  * @param argc
 763  * @param argv
 764  *
 765  * @return zero on success; otherwise error
 766  */
 767 static int do_gpt(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 768 {
 769         int ret = CMD_RET_SUCCESS;
 770         int dev = 0;
 771         char *ep;
 772         struct blk_desc *blk_dev_desc = NULL;
 773
 774 #ifndef CONFIG_CMD_GPT_RENAME
 775         if (argc < 4 || argc > 5)
 776 #else
 777         if (argc < 4 || argc > 6)
 778 #endif
 779                 return CMD_RET_USAGE;
 780
 781         dev = (int)simple_strtoul(argv[3], &ep, 10);
 782         if (!ep || ep[0] != '\0') {
 783                 printf("'%s' is not a number\n", argv[3]);
 784                 return CMD_RET_USAGE;
 785         }
 786         blk_dev_desc = blk_get_dev(argv[2], dev);
 787         if (!blk_dev_desc) {
 788                 printf("%s: %s dev %d NOT available\n",
 789                        __func__, argv[2], dev);
 790                 return CMD_RET_FAILURE;
 791         }
 792
 793         if ((strcmp(argv[1], "write") == 0) && (argc == 5)) {
 794                 printf("Writing GPT: ");
 795                 ret = gpt_default(blk_dev_desc, argv[4]);
 796         } else if ((strcmp(argv[1], "verify") == 0)) {
 797                 ret = gpt_verify(blk_dev_desc, argv[4]);
 798                 printf("Verify GPT: ");
 799         } else if (strcmp(argv[1], "guid") == 0) {
 800                 ret = do_disk_guid(blk_dev_desc, argv[4]);
 801 #ifdef CONFIG_CMD_GPT_RENAME
 802         } else if (strcmp(argv[1], "read") == 0) {
 803                 ret = do_get_gpt_info(blk_dev_desc);
 804         } else if ((strcmp(argv[1], "swap") == 0) ||
 805                    (strcmp(argv[1], "rename") == 0)) {
 806                 ret = do_rename_gpt_parts(blk_dev_desc, argv[1], argv[4], argv[5]);
 807 #endif
 808         } else {
 809                 return CMD_RET_USAGE;
 810         }
 811
 812         if (ret) {
 813                 printf("error!\n");
 814                 return CMD_RET_FAILURE;
 815         }
 816
 817         printf("success!\n");
 818         return CMD_RET_SUCCESS;
 819 }
 820
 821 U_BOOT_CMD(gpt, CONFIG_SYS_MAXARGS, 1, do_gpt,
 822         "GUID Partition Table",
 823         "<command> <interface> <dev> <partitions_list>\n"
 824         " - GUID partition table restoration and validity check\n"
 825         " Restore or verify GPT information on a device connected\n"
 826         " to interface\n"
 827         " Example usage:\n"
 828         " gpt write mmc 0 $partitions\n"
 829         " gpt verify mmc 0 $partitions\n"
 830         " read <interface> <dev>\n"
 831         "    - read GPT into a data structure for manipulation\n"
 832         " guid <interface> <dev>\n"
 833         "    - print disk GUID\n"
 834         " guid <interface> <dev> <varname>\n"
 835         "    - set environment variable to disk GUID\n"
 836         " Example usage:\n"
 837         " gpt guid mmc 0\n"
 838         " gpt guid mmc 0 varname\n"
 839 #ifdef CONFIG_CMD_GPT_RENAME
 840         "gpt partition renaming commands:\n"
 841         "gpt swap <interface> <dev> <name1> <name2>\n"
 842         "    - change all partitions named name1 to name2\n"
 843         "      and vice-versa\n"
 844         "gpt rename <interface> <dev> <part> <name>\n"
 845         "    - rename the specified partition\n"
 846         " Example usage:\n"
 847         " gpt swap mmc 0 foo bar\n"
 848         " gpt rename mmc 0 3 foo\n"
 849 #endif
 850 );