xref: /openbmc/u-boot/cmd/gpt.c (revision baefb63a)
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 = calloc(1, sizeof(struct disk_part));
194 	if (!newpart)
195 		return ERR_PTR(-ENOMEM);
196 
197 	newpart->gpt_part_info.start = info->start;
198 	newpart->gpt_part_info.size = info->size;
199 	newpart->gpt_part_info.blksz = info->blksz;
200 	strncpy((char *)newpart->gpt_part_info.name, (const char *)info->name,
201 		PART_NAME_LEN);
202 	newpart->gpt_part_info.name[PART_NAME_LEN - 1] = '\0';
203 	strncpy((char *)newpart->gpt_part_info.type, (const char *)info->type,
204 		PART_TYPE_LEN);
205 	newpart->gpt_part_info.type[PART_TYPE_LEN - 1] = '\0';
206 	newpart->gpt_part_info.bootable = info->bootable;
207 #ifdef CONFIG_PARTITION_UUIDS
208 	strncpy(newpart->gpt_part_info.uuid, (const char *)info->uuid,
209 		UUID_STR_LEN);
210 	/* UUID_STR_LEN is correct, as uuid[]'s length is UUID_STR_LEN+1 chars */
211 	newpart->gpt_part_info.uuid[UUID_STR_LEN] = '\0';
212 #endif
213 	newpart->partnum = partnum;
214 
215 	return newpart;
216 }
217 
218 static void prettyprint_part_size(char *sizestr, lbaint_t partsize,
219 				  lbaint_t blksize)
220 {
221 	unsigned long long partbytes, partmegabytes;
222 
223 	partbytes = partsize * blksize;
224 	partmegabytes = lldiv(partbytes, SZ_1M);
225 	snprintf(sizestr, 16, "%lluMiB", partmegabytes);
226 }
227 
228 static void print_gpt_info(void)
229 {
230 	struct list_head *pos;
231 	struct disk_part *curr;
232 	char partstartstr[16];
233 	char partsizestr[16];
234 
235 	list_for_each(pos, &disk_partitions) {
236 		curr = list_entry(pos, struct disk_part, list);
237 		prettyprint_part_size(partstartstr, curr->gpt_part_info.start,
238 				      curr->gpt_part_info.blksz);
239 		prettyprint_part_size(partsizestr, curr->gpt_part_info.size,
240 				      curr->gpt_part_info.blksz);
241 
242 		printf("Partition %d:\n", curr->partnum);
243 		printf("Start %s, size %s\n", partstartstr, partsizestr);
244 		printf("Block size %lu, name %s\n", curr->gpt_part_info.blksz,
245 		       curr->gpt_part_info.name);
246 		printf("Type %s, bootable %d\n", curr->gpt_part_info.type,
247 		       curr->gpt_part_info.bootable);
248 #ifdef CONFIG_PARTITION_UUIDS
249 		printf("UUID %s\n", curr->gpt_part_info.uuid);
250 #endif
251 		printf("\n");
252 	}
253 }
254 
255 /*
256  * create the string that upstream 'gpt write' command will accept as an
257  * argument
258  *
259  * From doc/README.gpt, Format of partitions layout:
260  *    "uuid_disk=...;name=u-boot,size=60MiB,uuid=...;
261  *	name=kernel,size=60MiB,uuid=...;"
262  * The fields 'name' and 'size' are mandatory for every partition.
263  * The field 'start' is optional. The fields 'uuid' and 'uuid_disk'
264  * are optional if CONFIG_RANDOM_UUID is enabled.
265  */
266 static int create_gpt_partitions_list(int numparts, const char *guid,
267 				      char *partitions_list)
268 {
269 	struct list_head *pos;
270 	struct disk_part *curr;
271 	char partstr[PART_NAME_LEN + 1];
272 
273 	if (!partitions_list)
274 		return -EINVAL;
275 
276 	strcpy(partitions_list, "uuid_disk=");
277 	strncat(partitions_list, guid, UUID_STR_LEN + 1);
278 	strcat(partitions_list, ";");
279 
280 	list_for_each(pos, &disk_partitions) {
281 		curr = list_entry(pos, struct disk_part, list);
282 		strcat(partitions_list, "name=");
283 		strncat(partitions_list, (const char *)curr->gpt_part_info.name,
284 			PART_NAME_LEN + 1);
285 		sprintf(partstr, ",start=0x%llx",
286 			(unsigned long long)curr->gpt_part_info.start *
287 					    curr->gpt_part_info.blksz);
288 		/* one extra byte for NULL */
289 		strncat(partitions_list, partstr, PART_NAME_LEN + 1);
290 		sprintf(partstr, ",size=0x%llx",
291 			(unsigned long long)curr->gpt_part_info.size *
292 					    curr->gpt_part_info.blksz);
293 		strncat(partitions_list, partstr, PART_NAME_LEN + 1);
294 
295 		strcat(partitions_list, ",uuid=");
296 		strncat(partitions_list, curr->gpt_part_info.uuid,
297 			UUID_STR_LEN + 1);
298 		strcat(partitions_list, ";");
299 	}
300 	return 0;
301 }
302 
303 /*
304  * read partition info into disk_partitions list where
305  * it can be printed or modified
306  */
307 static int get_gpt_info(struct blk_desc *dev_desc)
308 {
309 	/* start partition numbering at 1, as U-Boot does */
310 	int valid_parts = 0, p, ret;
311 	disk_partition_t info;
312 	struct disk_part *new_disk_part;
313 
314 	/*
315 	 * Always re-read partition info from device, in case
316 	 * it has changed
317 	 */
318 	INIT_LIST_HEAD(&disk_partitions);
319 
320 	for (p = 1; p <= MAX_SEARCH_PARTITIONS; p++) {
321 		ret = part_get_info(dev_desc, p, &info);
322 		if (ret)
323 			continue;
324 
325 		/* Add 1 here because counter is zero-based but p1 is
326 		   the first partition */
327 		new_disk_part = allocate_disk_part(&info, valid_parts+1);
328 		if (IS_ERR(new_disk_part))
329 			goto out;
330 
331 		list_add_tail(&new_disk_part->list, &disk_partitions);
332 		valid_parts++;
333 	}
334 	if (valid_parts == 0) {
335 		printf("** No valid partitions found **\n");
336 		goto out;
337 	}
338 	return valid_parts;
339  out:
340 	if (valid_parts >= 1)
341 		del_gpt_info();
342 	return -ENODEV;
343 }
344 
345 /* a wrapper to test get_gpt_info */
346 static int do_get_gpt_info(struct blk_desc *dev_desc)
347 {
348 	int ret;
349 
350 	ret = get_gpt_info(dev_desc);
351 	if (ret > 0) {
352 		print_gpt_info();
353 		del_gpt_info();
354 		return 0;
355 	}
356 	return ret;
357 }
358 #endif
359 
360 /**
361  * set_gpt_info(): Fill partition information from string
362  *		function allocates memory, remember to free!
363  *
364  * @param dev_desc - pointer block device descriptor
365  * @param str_part - pointer to string with partition information
366  * @param str_disk_guid - pointer to pointer to allocated string with disk guid
367  * @param partitions - pointer to pointer to allocated partitions array
368  * @param parts_count - number of partitions
369  *
370  * @return - zero on success, otherwise error
371  *
372  */
373 static int set_gpt_info(struct blk_desc *dev_desc,
374 			const char *str_part,
375 			char **str_disk_guid,
376 			disk_partition_t **partitions,
377 			u8 *parts_count)
378 {
379 	char *tok, *str, *s;
380 	int i;
381 	char *val, *p;
382 	int p_count;
383 	disk_partition_t *parts;
384 	int errno = 0;
385 	uint64_t size_ll, start_ll;
386 	lbaint_t offset = 0;
387 	int max_str_part = calc_parts_list_len(MAX_SEARCH_PARTITIONS);
388 
389 	debug("%s:  lba num: 0x%x %d\n", __func__,
390 	      (unsigned int)dev_desc->lba, (unsigned int)dev_desc->lba);
391 
392 	if (str_part == NULL)
393 		return -1;
394 
395 	str = strdup(str_part);
396 	if (str == NULL)
397 		return -ENOMEM;
398 
399 	/* extract disk guid */
400 	s = str;
401 	val = extract_val(str, "uuid_disk");
402 	if (!val) {
403 #ifdef CONFIG_RANDOM_UUID
404 		*str_disk_guid = malloc(UUID_STR_LEN + 1);
405 		if (*str_disk_guid == NULL)
406 			return -ENOMEM;
407 		gen_rand_uuid_str(*str_disk_guid, UUID_STR_FORMAT_STD);
408 #else
409 		free(str);
410 		return -2;
411 #endif
412 	} else {
413 		val = strsep(&val, ";");
414 		if (extract_env(val, &p))
415 			p = val;
416 		*str_disk_guid = strdup(p);
417 		free(val);
418 		/* Move s to first partition */
419 		strsep(&s, ";");
420 	}
421 	if (s == NULL) {
422 		printf("Error: is the partitions string NULL-terminated?\n");
423 		return -EINVAL;
424 	}
425 	if (strnlen(s, max_str_part) == 0)
426 		return -3;
427 
428 	i = strnlen(s, max_str_part) - 1;
429 	if (s[i] == ';')
430 		s[i] = '\0';
431 
432 	/* calculate expected number of partitions */
433 	p_count = 1;
434 	p = s;
435 	while (*p) {
436 		if (*p++ == ';')
437 			p_count++;
438 	}
439 
440 	/* allocate memory for partitions */
441 	parts = calloc(sizeof(disk_partition_t), p_count);
442 	if (parts == NULL)
443 		return -ENOMEM;
444 
445 	/* retrieve partitions data from string */
446 	for (i = 0; i < p_count; i++) {
447 		tok = strsep(&s, ";");
448 
449 		if (tok == NULL)
450 			break;
451 
452 		/* uuid */
453 		val = extract_val(tok, "uuid");
454 		if (!val) {
455 			/* 'uuid' is optional if random uuid's are enabled */
456 #ifdef CONFIG_RANDOM_UUID
457 			gen_rand_uuid_str(parts[i].uuid, UUID_STR_FORMAT_STD);
458 #else
459 			errno = -4;
460 			goto err;
461 #endif
462 		} else {
463 			if (extract_env(val, &p))
464 				p = val;
465 			if (strnlen(p, max_str_part) >= sizeof(parts[i].uuid)) {
466 				printf("Wrong uuid format for partition %d\n", i);
467 				errno = -4;
468 				goto err;
469 			}
470 			strncpy((char *)parts[i].uuid, p, max_str_part);
471 			free(val);
472 		}
473 #ifdef CONFIG_PARTITION_TYPE_GUID
474 		/* guid */
475 		val = extract_val(tok, "type");
476 		if (val) {
477 			/* 'type' is optional */
478 			if (extract_env(val, &p))
479 				p = val;
480 			if (strnlen(p, max_str_part) >= sizeof(parts[i].type_guid)) {
481 				printf("Wrong type guid format for partition %d\n",
482 				       i);
483 				errno = -4;
484 				goto err;
485 			}
486 			strncpy((char *)parts[i].type_guid, p, max_str_part);
487 			free(val);
488 		}
489 #endif
490 		/* name */
491 		val = extract_val(tok, "name");
492 		if (!val) { /* name is mandatory */
493 			errno = -4;
494 			goto err;
495 		}
496 		if (extract_env(val, &p))
497 			p = val;
498 		if (strnlen(p, max_str_part) >= sizeof(parts[i].name)) {
499 			errno = -4;
500 			goto err;
501 		}
502 		strncpy((char *)parts[i].name, p, max_str_part);
503 		free(val);
504 
505 		/* size */
506 		val = extract_val(tok, "size");
507 		if (!val) { /* 'size' is mandatory */
508 			errno = -4;
509 			goto err;
510 		}
511 		if (extract_env(val, &p))
512 			p = val;
513 		if ((strcmp(p, "-") == 0)) {
514 			/* Let part efi module to auto extend the size */
515 			parts[i].size = 0;
516 		} else {
517 			size_ll = ustrtoull(p, &p, 0);
518 			parts[i].size = lldiv(size_ll, dev_desc->blksz);
519 		}
520 
521 		free(val);
522 
523 		/* start address */
524 		val = extract_val(tok, "start");
525 		if (val) { /* start address is optional */
526 			if (extract_env(val, &p))
527 				p = val;
528 			start_ll = ustrtoull(p, &p, 0);
529 			parts[i].start = lldiv(start_ll, dev_desc->blksz);
530 			free(val);
531 		}
532 
533 		offset += parts[i].size + parts[i].start;
534 
535 		/* bootable */
536 		if (found_key(tok, "bootable"))
537 			parts[i].bootable = 1;
538 	}
539 
540 	*parts_count = p_count;
541 	*partitions = parts;
542 	free(str);
543 
544 	return 0;
545 err:
546 	free(str);
547 	free(*str_disk_guid);
548 	free(parts);
549 
550 	return errno;
551 }
552 
553 static int gpt_default(struct blk_desc *blk_dev_desc, const char *str_part)
554 {
555 	int ret;
556 	char *str_disk_guid;
557 	u8 part_count = 0;
558 	disk_partition_t *partitions = NULL;
559 
560 	/* fill partitions */
561 	ret = set_gpt_info(blk_dev_desc, str_part,
562 			&str_disk_guid, &partitions, &part_count);
563 	if (ret) {
564 		if (ret == -1)
565 			printf("No partition list provided\n");
566 		if (ret == -2)
567 			printf("Missing disk guid\n");
568 		if ((ret == -3) || (ret == -4))
569 			printf("Partition list incomplete\n");
570 		return -1;
571 	}
572 
573 	/* save partitions layout to disk */
574 	ret = gpt_restore(blk_dev_desc, str_disk_guid, partitions, part_count);
575 	free(str_disk_guid);
576 	free(partitions);
577 
578 	return ret;
579 }
580 
581 static int gpt_verify(struct blk_desc *blk_dev_desc, const char *str_part)
582 {
583 	ALLOC_CACHE_ALIGN_BUFFER_PAD(gpt_header, gpt_head, 1,
584 				     blk_dev_desc->blksz);
585 	disk_partition_t *partitions = NULL;
586 	gpt_entry *gpt_pte = NULL;
587 	char *str_disk_guid;
588 	u8 part_count = 0;
589 	int ret = 0;
590 
591 	/* fill partitions */
592 	ret = set_gpt_info(blk_dev_desc, str_part,
593 			&str_disk_guid, &partitions, &part_count);
594 	if (ret) {
595 		if (ret == -1) {
596 			printf("No partition list provided - only basic check\n");
597 			ret = gpt_verify_headers(blk_dev_desc, gpt_head,
598 						 &gpt_pte);
599 			goto out;
600 		}
601 		if (ret == -2)
602 			printf("Missing disk guid\n");
603 		if ((ret == -3) || (ret == -4))
604 			printf("Partition list incomplete\n");
605 		return -1;
606 	}
607 
608 	/* Check partition layout with provided pattern */
609 	ret = gpt_verify_partitions(blk_dev_desc, partitions, part_count,
610 				    gpt_head, &gpt_pte);
611 	free(str_disk_guid);
612 	free(partitions);
613  out:
614 	free(gpt_pte);
615 	return ret;
616 }
617 
618 static int do_disk_guid(struct blk_desc *dev_desc, char * const namestr)
619 {
620 	int ret;
621 	char disk_guid[UUID_STR_LEN + 1];
622 
623 	ret = get_disk_guid(dev_desc, disk_guid);
624 	if (ret < 0)
625 		return CMD_RET_FAILURE;
626 
627 	if (namestr)
628 		env_set(namestr, disk_guid);
629 	else
630 		printf("%s\n", disk_guid);
631 
632 	return ret;
633 }
634 
635 #ifdef CONFIG_CMD_GPT_RENAME
636 /*
637  * There are 3 malloc() calls in set_gpt_info() and there is no info about which
638  * failed.
639  */
640 static void set_gpt_cleanup(char **str_disk_guid,
641 			    disk_partition_t **partitions)
642 {
643 #ifdef CONFIG_RANDOM_UUID
644 	if (str_disk_guid)
645 		free(str_disk_guid);
646 #endif
647 	if (partitions)
648 		free(partitions);
649 }
650 
651 static int do_rename_gpt_parts(struct blk_desc *dev_desc, char *subcomm,
652 			       char *name1, char *name2)
653 {
654 	struct list_head *pos;
655 	struct disk_part *curr;
656 	disk_partition_t *new_partitions = NULL;
657 	char disk_guid[UUID_STR_LEN + 1];
658 	char *partitions_list, *str_disk_guid;
659 	u8 part_count = 0;
660 	int partlistlen, ret, numparts = 0, partnum, i = 1, ctr1 = 0, ctr2 = 0;
661 
662 	if ((subcomm == NULL) || (name1 == NULL) || (name2 == NULL) ||
663 	    (strcmp(subcomm, "swap") && (strcmp(subcomm, "rename"))))
664 		return -EINVAL;
665 
666 	ret = get_disk_guid(dev_desc, disk_guid);
667 	if (ret < 0)
668 		return ret;
669 	/*
670 	 * Allocates disk_partitions, requiring matching call to del_gpt_info()
671 	 * if successful.
672 	 */
673 	numparts = get_gpt_info(dev_desc);
674 	if (numparts <=  0)
675 		return numparts ? numparts : -ENODEV;
676 
677 	partlistlen = calc_parts_list_len(numparts);
678 	partitions_list = malloc(partlistlen);
679 	if (!partitions_list) {
680 		del_gpt_info();
681 		return -ENOMEM;
682 	}
683 	memset(partitions_list, '\0', partlistlen);
684 
685 	ret = create_gpt_partitions_list(numparts, disk_guid, partitions_list);
686 	if (ret < 0) {
687 		free(partitions_list);
688 		return ret;
689 	}
690 	/*
691 	 * Uncomment the following line to print a string that 'gpt write'
692 	 * or 'gpt verify' will accept as input.
693 	 */
694 	debug("OLD partitions_list is %s with %u chars\n", partitions_list,
695 	      (unsigned)strlen(partitions_list));
696 
697 	/* set_gpt_info allocates new_partitions and str_disk_guid */
698 	ret = set_gpt_info(dev_desc, partitions_list, &str_disk_guid,
699 			   &new_partitions, &part_count);
700 	if (ret < 0) {
701 		del_gpt_info();
702 		free(partitions_list);
703 		if (ret == -ENOMEM)
704 			set_gpt_cleanup(&str_disk_guid, &new_partitions);
705 		else
706 			goto out;
707 	}
708 
709 	if (!strcmp(subcomm, "swap")) {
710 		if ((strlen(name1) > PART_NAME_LEN) || (strlen(name2) > PART_NAME_LEN)) {
711 			printf("Names longer than %d characters are truncated.\n", PART_NAME_LEN);
712 			ret = -EINVAL;
713 			goto out;
714 		}
715 		list_for_each(pos, &disk_partitions) {
716 			curr = list_entry(pos, struct disk_part, list);
717 			if (!strcmp((char *)curr->gpt_part_info.name, name1)) {
718 				strcpy((char *)curr->gpt_part_info.name, name2);
719 				ctr1++;
720 			} else if (!strcmp((char *)curr->gpt_part_info.name, name2)) {
721 				strcpy((char *)curr->gpt_part_info.name, name1);
722 				ctr2++;
723 			}
724 		}
725 		if ((ctr1 + ctr2 < 2) || (ctr1 != ctr2)) {
726 			printf("Cannot swap partition names except in pairs.\n");
727 			ret = -EINVAL;
728 			goto out;
729 		}
730 	} else { /* rename */
731 		if (strlen(name2) > PART_NAME_LEN) {
732 			printf("Names longer than %d characters are truncated.\n", PART_NAME_LEN);
733 			ret = -EINVAL;
734 			goto out;
735 		}
736 		partnum = (int)simple_strtol(name1, NULL, 10);
737 		if ((partnum < 0) || (partnum > numparts)) {
738 			printf("Illegal partition number %s\n", name1);
739 			ret = -EINVAL;
740 			goto out;
741 		}
742 		ret = part_get_info(dev_desc, partnum, new_partitions);
743 		if (ret < 0)
744 			goto out;
745 
746 		/* U-Boot partition numbering starts at 1 */
747 		list_for_each(pos, &disk_partitions) {
748 			curr = list_entry(pos, struct disk_part, list);
749 			if (i == partnum) {
750 				strcpy((char *)curr->gpt_part_info.name, name2);
751 				break;
752 			}
753 			i++;
754 		}
755 	}
756 
757 	ret = create_gpt_partitions_list(numparts, disk_guid, partitions_list);
758 	if (ret < 0)
759 		goto out;
760 	debug("NEW partitions_list is %s with %u chars\n", partitions_list,
761 	      (unsigned)strlen(partitions_list));
762 
763 	ret = set_gpt_info(dev_desc, partitions_list, &str_disk_guid,
764 			   &new_partitions, &part_count);
765 	/*
766 	 * Even though valid pointers are here passed into set_gpt_info(),
767 	 * it mallocs again, and there's no way to tell which failed.
768 	 */
769 	if (ret < 0) {
770 		del_gpt_info();
771 		free(partitions_list);
772 		if (ret == -ENOMEM)
773 			set_gpt_cleanup(&str_disk_guid, &new_partitions);
774 		else
775 			goto out;
776 	}
777 
778 	debug("Writing new partition table\n");
779 	ret = gpt_restore(dev_desc, disk_guid, new_partitions, numparts);
780 	if (ret < 0) {
781 		printf("Writing new partition table failed\n");
782 		goto out;
783 	}
784 
785 	debug("Reading back new partition table\n");
786 	/*
787 	 * Empty the existing disk_partitions list, as otherwise the memory in
788 	 * the original list is unreachable.
789 	 */
790 	del_gpt_info();
791 	numparts = get_gpt_info(dev_desc);
792 	if (numparts <=  0) {
793 		ret = numparts ? numparts : -ENODEV;
794 		goto out;
795 	}
796 	printf("new partition table with %d partitions is:\n", numparts);
797 	print_gpt_info();
798 	del_gpt_info();
799  out:
800 	free(new_partitions);
801 	free(str_disk_guid);
802 	free(partitions_list);
803 	return ret;
804 }
805 #endif
806 
807 /**
808  * do_gpt(): Perform GPT operations
809  *
810  * @param cmdtp - command name
811  * @param flag
812  * @param argc
813  * @param argv
814  *
815  * @return zero on success; otherwise error
816  */
817 static int do_gpt(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
818 {
819 	int ret = CMD_RET_SUCCESS;
820 	int dev = 0;
821 	char *ep;
822 	struct blk_desc *blk_dev_desc = NULL;
823 
824 #ifndef CONFIG_CMD_GPT_RENAME
825 	if (argc < 4 || argc > 5)
826 #else
827 	if (argc < 4 || argc > 6)
828 #endif
829 		return CMD_RET_USAGE;
830 
831 	dev = (int)simple_strtoul(argv[3], &ep, 10);
832 	if (!ep || ep[0] != '\0') {
833 		printf("'%s' is not a number\n", argv[3]);
834 		return CMD_RET_USAGE;
835 	}
836 	blk_dev_desc = blk_get_dev(argv[2], dev);
837 	if (!blk_dev_desc) {
838 		printf("%s: %s dev %d NOT available\n",
839 		       __func__, argv[2], dev);
840 		return CMD_RET_FAILURE;
841 	}
842 
843 	if ((strcmp(argv[1], "write") == 0) && (argc == 5)) {
844 		printf("Writing GPT: ");
845 		ret = gpt_default(blk_dev_desc, argv[4]);
846 	} else if ((strcmp(argv[1], "verify") == 0)) {
847 		ret = gpt_verify(blk_dev_desc, argv[4]);
848 		printf("Verify GPT: ");
849 	} else if (strcmp(argv[1], "guid") == 0) {
850 		ret = do_disk_guid(blk_dev_desc, argv[4]);
851 #ifdef CONFIG_CMD_GPT_RENAME
852 	} else if (strcmp(argv[1], "read") == 0) {
853 		ret = do_get_gpt_info(blk_dev_desc);
854 	} else if ((strcmp(argv[1], "swap") == 0) ||
855 		   (strcmp(argv[1], "rename") == 0)) {
856 		ret = do_rename_gpt_parts(blk_dev_desc, argv[1], argv[4], argv[5]);
857 #endif
858 	} else {
859 		return CMD_RET_USAGE;
860 	}
861 
862 	if (ret) {
863 		printf("error!\n");
864 		return CMD_RET_FAILURE;
865 	}
866 
867 	printf("success!\n");
868 	return CMD_RET_SUCCESS;
869 }
870 
871 U_BOOT_CMD(gpt, CONFIG_SYS_MAXARGS, 1, do_gpt,
872 	"GUID Partition Table",
873 	"<command> <interface> <dev> <partitions_list>\n"
874 	" - GUID partition table restoration and validity check\n"
875 	" Restore or verify GPT information on a device connected\n"
876 	" to interface\n"
877 	" Example usage:\n"
878 	" gpt write mmc 0 $partitions\n"
879 	" gpt verify mmc 0 $partitions\n"
880 	" read <interface> <dev>\n"
881 	"    - read GPT into a data structure for manipulation\n"
882 	" guid <interface> <dev>\n"
883 	"    - print disk GUID\n"
884 	" guid <interface> <dev> <varname>\n"
885 	"    - set environment variable to disk GUID\n"
886 	" Example usage:\n"
887 	" gpt guid mmc 0\n"
888 	" gpt guid mmc 0 varname\n"
889 #ifdef CONFIG_CMD_GPT_RENAME
890 	"gpt partition renaming commands:\n"
891 	"gpt swap <interface> <dev> <name1> <name2>\n"
892 	"    - change all partitions named name1 to name2\n"
893 	"      and vice-versa\n"
894 	"gpt rename <interface> <dev> <part> <name>\n"
895 	"    - rename the specified partition\n"
896 	" Example usage:\n"
897 	" gpt swap mmc 0 foo bar\n"
898 	" gpt rename mmc 0 3 foo\n"
899 #endif
900 );
901