xref: /openbmc/u-boot/disk/part_efi.c (revision 68968901)
1 /*
2  * Copyright (C) 2008 RuggedCom, Inc.
3  * Richard Retanubun <RichardRetanubun@RuggedCom.com>
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 /*
9  * NOTE:
10  *   when CONFIG_SYS_64BIT_LBA is not defined, lbaint_t is 32 bits; this
11  *   limits the maximum size of addressable storage to < 2 Terra Bytes
12  */
13 #include <asm/unaligned.h>
14 #include <common.h>
15 #include <command.h>
16 #include <ide.h>
17 #include <malloc.h>
18 #include <part_efi.h>
19 #include <linux/ctype.h>
20 
21 DECLARE_GLOBAL_DATA_PTR;
22 
23 #ifdef HAVE_BLOCK_DEVICE
24 /**
25  * efi_crc32() - EFI version of crc32 function
26  * @buf: buffer to calculate crc32 of
27  * @len - length of buf
28  *
29  * Description: Returns EFI-style CRC32 value for @buf
30  */
31 static inline u32 efi_crc32(const void *buf, u32 len)
32 {
33 	return crc32(0, buf, len);
34 }
35 
36 /*
37  * Private function prototypes
38  */
39 
40 static int pmbr_part_valid(struct partition *part);
41 static int is_pmbr_valid(legacy_mbr * mbr);
42 static int is_gpt_valid(block_dev_desc_t *dev_desc, u64 lba,
43 				gpt_header *pgpt_head, gpt_entry **pgpt_pte);
44 static gpt_entry *alloc_read_gpt_entries(block_dev_desc_t * dev_desc,
45 				gpt_header * pgpt_head);
46 static int is_pte_valid(gpt_entry * pte);
47 
48 static char *print_efiname(gpt_entry *pte)
49 {
50 	static char name[PARTNAME_SZ + 1];
51 	int i;
52 	for (i = 0; i < PARTNAME_SZ; i++) {
53 		u8 c;
54 		c = pte->partition_name[i] & 0xff;
55 		c = (c && !isprint(c)) ? '.' : c;
56 		name[i] = c;
57 	}
58 	name[PARTNAME_SZ] = 0;
59 	return name;
60 }
61 
62 static efi_guid_t system_guid = PARTITION_SYSTEM_GUID;
63 
64 static inline int is_bootable(gpt_entry *p)
65 {
66 	return p->attributes.fields.legacy_bios_bootable ||
67 		!memcmp(&(p->partition_type_guid), &system_guid,
68 			sizeof(efi_guid_t));
69 }
70 
71 #ifdef CONFIG_EFI_PARTITION
72 /*
73  * Public Functions (include/part.h)
74  */
75 
76 void print_part_efi(block_dev_desc_t * dev_desc)
77 {
78 	ALLOC_CACHE_ALIGN_BUFFER_PAD(gpt_header, gpt_head, 1, dev_desc->blksz);
79 	gpt_entry *gpt_pte = NULL;
80 	int i = 0;
81 	char uuid[37];
82 	unsigned char *uuid_bin;
83 
84 	if (!dev_desc) {
85 		printf("%s: Invalid Argument(s)\n", __func__);
86 		return;
87 	}
88 	/* This function validates AND fills in the GPT header and PTE */
89 	if (is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA,
90 			 gpt_head, &gpt_pte) != 1) {
91 		printf("%s: *** ERROR: Invalid GPT ***\n", __func__);
92 		if (is_gpt_valid(dev_desc, (dev_desc->lba - 1),
93 				 gpt_head, &gpt_pte) != 1) {
94 			printf("%s: *** ERROR: Invalid Backup GPT ***\n",
95 			       __func__);
96 			return;
97 		} else {
98 			printf("%s: ***        Using Backup GPT ***\n",
99 			       __func__);
100 		}
101 	}
102 
103 	debug("%s: gpt-entry at %p\n", __func__, gpt_pte);
104 
105 	printf("Part\tStart LBA\tEnd LBA\t\tName\n");
106 	printf("\tAttributes\n");
107 	printf("\tType GUID\n");
108 	printf("\tPartition GUID\n");
109 
110 	for (i = 0; i < le32_to_cpu(gpt_head->num_partition_entries); i++) {
111 		/* Stop at the first non valid PTE */
112 		if (!is_pte_valid(&gpt_pte[i]))
113 			break;
114 
115 		printf("%3d\t0x%08llx\t0x%08llx\t\"%s\"\n", (i + 1),
116 			le64_to_cpu(gpt_pte[i].starting_lba),
117 			le64_to_cpu(gpt_pte[i].ending_lba),
118 			print_efiname(&gpt_pte[i]));
119 		printf("\tattrs:\t0x%016llx\n", gpt_pte[i].attributes.raw);
120 		uuid_bin = (unsigned char *)gpt_pte[i].partition_type_guid.b;
121 		uuid_bin_to_str(uuid_bin, uuid, UUID_STR_FORMAT_GUID);
122 		printf("\ttype:\t%s\n", uuid);
123 		uuid_bin = (unsigned char *)gpt_pte[i].unique_partition_guid.b;
124 		uuid_bin_to_str(uuid_bin, uuid, UUID_STR_FORMAT_GUID);
125 		printf("\tguid:\t%s\n", uuid);
126 	}
127 
128 	/* Remember to free pte */
129 	free(gpt_pte);
130 	return;
131 }
132 
133 int get_partition_info_efi(block_dev_desc_t * dev_desc, int part,
134 				disk_partition_t * info)
135 {
136 	ALLOC_CACHE_ALIGN_BUFFER_PAD(gpt_header, gpt_head, 1, dev_desc->blksz);
137 	gpt_entry *gpt_pte = NULL;
138 
139 	/* "part" argument must be at least 1 */
140 	if (!dev_desc || !info || part < 1) {
141 		printf("%s: Invalid Argument(s)\n", __func__);
142 		return -1;
143 	}
144 
145 	/* This function validates AND fills in the GPT header and PTE */
146 	if (is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA,
147 			gpt_head, &gpt_pte) != 1) {
148 		printf("%s: *** ERROR: Invalid GPT ***\n", __func__);
149 		if (is_gpt_valid(dev_desc, (dev_desc->lba - 1),
150 				 gpt_head, &gpt_pte) != 1) {
151 			printf("%s: *** ERROR: Invalid Backup GPT ***\n",
152 			       __func__);
153 			return -1;
154 		} else {
155 			printf("%s: ***        Using Backup GPT ***\n",
156 			       __func__);
157 		}
158 	}
159 
160 	if (part > le32_to_cpu(gpt_head->num_partition_entries) ||
161 	    !is_pte_valid(&gpt_pte[part - 1])) {
162 		debug("%s: *** ERROR: Invalid partition number %d ***\n",
163 			__func__, part);
164 		free(gpt_pte);
165 		return -1;
166 	}
167 
168 	/* The 'lbaint_t' casting may limit the maximum disk size to 2 TB */
169 	info->start = (lbaint_t)le64_to_cpu(gpt_pte[part - 1].starting_lba);
170 	/* The ending LBA is inclusive, to calculate size, add 1 to it */
171 	info->size = (lbaint_t)le64_to_cpu(gpt_pte[part - 1].ending_lba) + 1
172 		     - info->start;
173 	info->blksz = dev_desc->blksz;
174 
175 	sprintf((char *)info->name, "%s",
176 			print_efiname(&gpt_pte[part - 1]));
177 	sprintf((char *)info->type, "U-Boot");
178 	info->bootable = is_bootable(&gpt_pte[part - 1]);
179 #ifdef CONFIG_PARTITION_UUIDS
180 	uuid_bin_to_str(gpt_pte[part - 1].unique_partition_guid.b, info->uuid,
181 			UUID_STR_FORMAT_GUID);
182 #endif
183 
184 	debug("%s: start 0x" LBAF ", size 0x" LBAF ", name %s\n", __func__,
185 	      info->start, info->size, info->name);
186 
187 	/* Remember to free pte */
188 	free(gpt_pte);
189 	return 0;
190 }
191 
192 int get_partition_info_efi_by_name(block_dev_desc_t *dev_desc,
193 	const char *name, disk_partition_t *info)
194 {
195 	int ret;
196 	int i;
197 	for (i = 1; i < GPT_ENTRY_NUMBERS; i++) {
198 		ret = get_partition_info_efi(dev_desc, i, info);
199 		if (ret != 0) {
200 			/* no more entries in table */
201 			return -1;
202 		}
203 		if (strcmp(name, (const char *)info->name) == 0) {
204 			/* matched */
205 			return 0;
206 		}
207 	}
208 	return -2;
209 }
210 
211 int test_part_efi(block_dev_desc_t * dev_desc)
212 {
213 	ALLOC_CACHE_ALIGN_BUFFER_PAD(legacy_mbr, legacymbr, 1, dev_desc->blksz);
214 
215 	/* Read legacy MBR from block 0 and validate it */
216 	if ((dev_desc->block_read(dev_desc->dev, 0, 1, (ulong *)legacymbr) != 1)
217 		|| (is_pmbr_valid(legacymbr) != 1)) {
218 		return -1;
219 	}
220 	return 0;
221 }
222 
223 /**
224  * set_protective_mbr(): Set the EFI protective MBR
225  * @param dev_desc - block device descriptor
226  *
227  * @return - zero on success, otherwise error
228  */
229 static int set_protective_mbr(block_dev_desc_t *dev_desc)
230 {
231 	/* Setup the Protective MBR */
232 	ALLOC_CACHE_ALIGN_BUFFER(legacy_mbr, p_mbr, 1);
233 	memset(p_mbr, 0, sizeof(*p_mbr));
234 
235 	if (p_mbr == NULL) {
236 		printf("%s: calloc failed!\n", __func__);
237 		return -1;
238 	}
239 	/* Append signature */
240 	p_mbr->signature = MSDOS_MBR_SIGNATURE;
241 	p_mbr->partition_record[0].sys_ind = EFI_PMBR_OSTYPE_EFI_GPT;
242 	p_mbr->partition_record[0].start_sect = 1;
243 	p_mbr->partition_record[0].nr_sects = (u32) dev_desc->lba;
244 
245 	/* Write MBR sector to the MMC device */
246 	if (dev_desc->block_write(dev_desc->dev, 0, 1, p_mbr) != 1) {
247 		printf("** Can't write to device %d **\n",
248 			dev_desc->dev);
249 		return -1;
250 	}
251 
252 	return 0;
253 }
254 
255 int write_gpt_table(block_dev_desc_t *dev_desc,
256 		gpt_header *gpt_h, gpt_entry *gpt_e)
257 {
258 	const int pte_blk_cnt = BLOCK_CNT((gpt_h->num_partition_entries
259 					   * sizeof(gpt_entry)), dev_desc);
260 	u32 calc_crc32;
261 	u64 val;
262 
263 	debug("max lba: %x\n", (u32) dev_desc->lba);
264 	/* Setup the Protective MBR */
265 	if (set_protective_mbr(dev_desc) < 0)
266 		goto err;
267 
268 	/* Generate CRC for the Primary GPT Header */
269 	calc_crc32 = efi_crc32((const unsigned char *)gpt_e,
270 			      le32_to_cpu(gpt_h->num_partition_entries) *
271 			      le32_to_cpu(gpt_h->sizeof_partition_entry));
272 	gpt_h->partition_entry_array_crc32 = cpu_to_le32(calc_crc32);
273 
274 	calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
275 			      le32_to_cpu(gpt_h->header_size));
276 	gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
277 
278 	/* Write the First GPT to the block right after the Legacy MBR */
279 	if (dev_desc->block_write(dev_desc->dev, 1, 1, gpt_h) != 1)
280 		goto err;
281 
282 	if (dev_desc->block_write(dev_desc->dev, 2, pte_blk_cnt, gpt_e)
283 	    != pte_blk_cnt)
284 		goto err;
285 
286 	/* recalculate the values for the Backup GPT Header */
287 	val = le64_to_cpu(gpt_h->my_lba);
288 	gpt_h->my_lba = gpt_h->alternate_lba;
289 	gpt_h->alternate_lba = cpu_to_le64(val);
290 	gpt_h->header_crc32 = 0;
291 
292 	calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
293 			      le32_to_cpu(gpt_h->header_size));
294 	gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
295 
296 	if (dev_desc->block_write(dev_desc->dev,
297 				  (lbaint_t)le64_to_cpu(gpt_h->last_usable_lba)
298 				  + 1,
299 				  pte_blk_cnt, gpt_e) != pte_blk_cnt)
300 		goto err;
301 
302 	if (dev_desc->block_write(dev_desc->dev,
303 				  (lbaint_t)le64_to_cpu(gpt_h->my_lba), 1,
304 				  gpt_h) != 1)
305 		goto err;
306 
307 	debug("GPT successfully written to block device!\n");
308 	return 0;
309 
310  err:
311 	printf("** Can't write to device %d **\n", dev_desc->dev);
312 	return -1;
313 }
314 
315 int gpt_fill_pte(gpt_header *gpt_h, gpt_entry *gpt_e,
316 		disk_partition_t *partitions, int parts)
317 {
318 	lbaint_t offset = (lbaint_t)le64_to_cpu(gpt_h->first_usable_lba);
319 	lbaint_t start;
320 	lbaint_t last_usable_lba = (lbaint_t)
321 			le64_to_cpu(gpt_h->last_usable_lba);
322 	int i, k;
323 	size_t efiname_len, dosname_len;
324 #ifdef CONFIG_PARTITION_UUIDS
325 	char *str_uuid;
326 	unsigned char *bin_uuid;
327 #endif
328 
329 	for (i = 0; i < parts; i++) {
330 		/* partition starting lba */
331 		start = partitions[i].start;
332 		if (start && (start < offset)) {
333 			printf("Partition overlap\n");
334 			return -1;
335 		}
336 		if (start) {
337 			gpt_e[i].starting_lba = cpu_to_le64(start);
338 			offset = start + partitions[i].size;
339 		} else {
340 			gpt_e[i].starting_lba = cpu_to_le64(offset);
341 			offset += partitions[i].size;
342 		}
343 		if (offset >= last_usable_lba) {
344 			printf("Partitions layout exceds disk size\n");
345 			return -1;
346 		}
347 		/* partition ending lba */
348 		if ((i == parts - 1) && (partitions[i].size == 0))
349 			/* extend the last partition to maximuim */
350 			gpt_e[i].ending_lba = gpt_h->last_usable_lba;
351 		else
352 			gpt_e[i].ending_lba = cpu_to_le64(offset - 1);
353 
354 		/* partition type GUID */
355 		memcpy(gpt_e[i].partition_type_guid.b,
356 			&PARTITION_BASIC_DATA_GUID, 16);
357 
358 #ifdef CONFIG_PARTITION_UUIDS
359 		str_uuid = partitions[i].uuid;
360 		bin_uuid = gpt_e[i].unique_partition_guid.b;
361 
362 		if (uuid_str_to_bin(str_uuid, bin_uuid, UUID_STR_FORMAT_STD)) {
363 			printf("Partition no. %d: invalid guid: %s\n",
364 				i, str_uuid);
365 			return -1;
366 		}
367 #endif
368 
369 		/* partition attributes */
370 		memset(&gpt_e[i].attributes, 0,
371 		       sizeof(gpt_entry_attributes));
372 
373 		/* partition name */
374 		efiname_len = sizeof(gpt_e[i].partition_name)
375 			/ sizeof(efi_char16_t);
376 		dosname_len = sizeof(partitions[i].name);
377 
378 		memset(gpt_e[i].partition_name, 0,
379 		       sizeof(gpt_e[i].partition_name));
380 
381 		for (k = 0; k < min(dosname_len, efiname_len); k++)
382 			gpt_e[i].partition_name[k] =
383 				(efi_char16_t)(partitions[i].name[k]);
384 
385 		debug("%s: name: %s offset[%d]: 0x" LBAF
386 		      " size[%d]: 0x" LBAF "\n",
387 		      __func__, partitions[i].name, i,
388 		      offset, i, partitions[i].size);
389 	}
390 
391 	return 0;
392 }
393 
394 int gpt_fill_header(block_dev_desc_t *dev_desc, gpt_header *gpt_h,
395 		char *str_guid, int parts_count)
396 {
397 	gpt_h->signature = cpu_to_le64(GPT_HEADER_SIGNATURE);
398 	gpt_h->revision = cpu_to_le32(GPT_HEADER_REVISION_V1);
399 	gpt_h->header_size = cpu_to_le32(sizeof(gpt_header));
400 	gpt_h->my_lba = cpu_to_le64(1);
401 	gpt_h->alternate_lba = cpu_to_le64(dev_desc->lba - 1);
402 	gpt_h->first_usable_lba = cpu_to_le64(34);
403 	gpt_h->last_usable_lba = cpu_to_le64(dev_desc->lba - 34);
404 	gpt_h->partition_entry_lba = cpu_to_le64(2);
405 	gpt_h->num_partition_entries = cpu_to_le32(GPT_ENTRY_NUMBERS);
406 	gpt_h->sizeof_partition_entry = cpu_to_le32(sizeof(gpt_entry));
407 	gpt_h->header_crc32 = 0;
408 	gpt_h->partition_entry_array_crc32 = 0;
409 
410 	if (uuid_str_to_bin(str_guid, gpt_h->disk_guid.b, UUID_STR_FORMAT_GUID))
411 		return -1;
412 
413 	return 0;
414 }
415 
416 int gpt_restore(block_dev_desc_t *dev_desc, char *str_disk_guid,
417 		disk_partition_t *partitions, int parts_count)
418 {
419 	int ret;
420 
421 	gpt_header *gpt_h = calloc(1, PAD_TO_BLOCKSIZE(sizeof(gpt_header),
422 						       dev_desc));
423 	gpt_entry *gpt_e;
424 
425 	if (gpt_h == NULL) {
426 		printf("%s: calloc failed!\n", __func__);
427 		return -1;
428 	}
429 
430 	gpt_e = calloc(1, PAD_TO_BLOCKSIZE(GPT_ENTRY_NUMBERS
431 					       * sizeof(gpt_entry),
432 					       dev_desc));
433 	if (gpt_e == NULL) {
434 		printf("%s: calloc failed!\n", __func__);
435 		free(gpt_h);
436 		return -1;
437 	}
438 
439 	/* Generate Primary GPT header (LBA1) */
440 	ret = gpt_fill_header(dev_desc, gpt_h, str_disk_guid, parts_count);
441 	if (ret)
442 		goto err;
443 
444 	/* Generate partition entries */
445 	ret = gpt_fill_pte(gpt_h, gpt_e, partitions, parts_count);
446 	if (ret)
447 		goto err;
448 
449 	/* Write GPT partition table */
450 	ret = write_gpt_table(dev_desc, gpt_h, gpt_e);
451 
452 err:
453 	free(gpt_e);
454 	free(gpt_h);
455 	return ret;
456 }
457 #endif
458 
459 /*
460  * Private functions
461  */
462 /*
463  * pmbr_part_valid(): Check for EFI partition signature
464  *
465  * Returns: 1 if EFI GPT partition type is found.
466  */
467 static int pmbr_part_valid(struct partition *part)
468 {
469 	if (part->sys_ind == EFI_PMBR_OSTYPE_EFI_GPT &&
470 		get_unaligned_le32(&part->start_sect) == 1UL) {
471 		return 1;
472 	}
473 
474 	return 0;
475 }
476 
477 /*
478  * is_pmbr_valid(): test Protective MBR for validity
479  *
480  * Returns: 1 if PMBR is valid, 0 otherwise.
481  * Validity depends on two things:
482  *  1) MSDOS signature is in the last two bytes of the MBR
483  *  2) One partition of type 0xEE is found, checked by pmbr_part_valid()
484  */
485 static int is_pmbr_valid(legacy_mbr * mbr)
486 {
487 	int i = 0;
488 
489 	if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
490 		return 0;
491 
492 	for (i = 0; i < 4; i++) {
493 		if (pmbr_part_valid(&mbr->partition_record[i])) {
494 			return 1;
495 		}
496 	}
497 	return 0;
498 }
499 
500 /**
501  * is_gpt_valid() - tests one GPT header and PTEs for validity
502  *
503  * lba is the logical block address of the GPT header to test
504  * gpt is a GPT header ptr, filled on return.
505  * ptes is a PTEs ptr, filled on return.
506  *
507  * Description: returns 1 if valid,  0 on error.
508  * If valid, returns pointers to PTEs.
509  */
510 static int is_gpt_valid(block_dev_desc_t *dev_desc, u64 lba,
511 			gpt_header *pgpt_head, gpt_entry **pgpt_pte)
512 {
513 	u32 crc32_backup = 0;
514 	u32 calc_crc32;
515 	u64 lastlba;
516 
517 	if (!dev_desc || !pgpt_head) {
518 		printf("%s: Invalid Argument(s)\n", __func__);
519 		return 0;
520 	}
521 
522 	/* Read GPT Header from device */
523 	if (dev_desc->block_read(dev_desc->dev, (lbaint_t)lba, 1, pgpt_head)
524 			!= 1) {
525 		printf("*** ERROR: Can't read GPT header ***\n");
526 		return 0;
527 	}
528 
529 	/* Check the GPT header signature */
530 	if (le64_to_cpu(pgpt_head->signature) != GPT_HEADER_SIGNATURE) {
531 		printf("GUID Partition Table Header signature is wrong:"
532 			"0x%llX != 0x%llX\n",
533 			le64_to_cpu(pgpt_head->signature),
534 			GPT_HEADER_SIGNATURE);
535 		return 0;
536 	}
537 
538 	/* Check the GUID Partition Table CRC */
539 	memcpy(&crc32_backup, &pgpt_head->header_crc32, sizeof(crc32_backup));
540 	memset(&pgpt_head->header_crc32, 0, sizeof(pgpt_head->header_crc32));
541 
542 	calc_crc32 = efi_crc32((const unsigned char *)pgpt_head,
543 		le32_to_cpu(pgpt_head->header_size));
544 
545 	memcpy(&pgpt_head->header_crc32, &crc32_backup, sizeof(crc32_backup));
546 
547 	if (calc_crc32 != le32_to_cpu(crc32_backup)) {
548 		printf("GUID Partition Table Header CRC is wrong:"
549 			"0x%x != 0x%x\n",
550 		       le32_to_cpu(crc32_backup), calc_crc32);
551 		return 0;
552 	}
553 
554 	/* Check that the my_lba entry points to the LBA that contains the GPT */
555 	if (le64_to_cpu(pgpt_head->my_lba) != lba) {
556 		printf("GPT: my_lba incorrect: %llX != %llX\n",
557 			le64_to_cpu(pgpt_head->my_lba),
558 			lba);
559 		return 0;
560 	}
561 
562 	/* Check the first_usable_lba and last_usable_lba are within the disk. */
563 	lastlba = (u64)dev_desc->lba;
564 	if (le64_to_cpu(pgpt_head->first_usable_lba) > lastlba) {
565 		printf("GPT: first_usable_lba incorrect: %llX > %llX\n",
566 			le64_to_cpu(pgpt_head->first_usable_lba), lastlba);
567 		return 0;
568 	}
569 	if (le64_to_cpu(pgpt_head->last_usable_lba) > lastlba) {
570 		printf("GPT: last_usable_lba incorrect: %llX > %llX\n",
571 			le64_to_cpu(pgpt_head->last_usable_lba), lastlba);
572 		return 0;
573 	}
574 
575 	debug("GPT: first_usable_lba: %llX last_usable_lba %llX last lba %llX\n",
576 		le64_to_cpu(pgpt_head->first_usable_lba),
577 		le64_to_cpu(pgpt_head->last_usable_lba), lastlba);
578 
579 	/* Read and allocate Partition Table Entries */
580 	*pgpt_pte = alloc_read_gpt_entries(dev_desc, pgpt_head);
581 	if (*pgpt_pte == NULL) {
582 		printf("GPT: Failed to allocate memory for PTE\n");
583 		return 0;
584 	}
585 
586 	/* Check the GUID Partition Table Entry Array CRC */
587 	calc_crc32 = efi_crc32((const unsigned char *)*pgpt_pte,
588 		le32_to_cpu(pgpt_head->num_partition_entries) *
589 		le32_to_cpu(pgpt_head->sizeof_partition_entry));
590 
591 	if (calc_crc32 != le32_to_cpu(pgpt_head->partition_entry_array_crc32)) {
592 		printf("GUID Partition Table Entry Array CRC is wrong:"
593 			"0x%x != 0x%x\n",
594 			le32_to_cpu(pgpt_head->partition_entry_array_crc32),
595 			calc_crc32);
596 
597 		free(*pgpt_pte);
598 		return 0;
599 	}
600 
601 	/* We're done, all's well */
602 	return 1;
603 }
604 
605 /**
606  * alloc_read_gpt_entries(): reads partition entries from disk
607  * @dev_desc
608  * @gpt - GPT header
609  *
610  * Description: Returns ptes on success,  NULL on error.
611  * Allocates space for PTEs based on information found in @gpt.
612  * Notes: remember to free pte when you're done!
613  */
614 static gpt_entry *alloc_read_gpt_entries(block_dev_desc_t * dev_desc,
615 					 gpt_header * pgpt_head)
616 {
617 	size_t count = 0, blk_cnt;
618 	gpt_entry *pte = NULL;
619 
620 	if (!dev_desc || !pgpt_head) {
621 		printf("%s: Invalid Argument(s)\n", __func__);
622 		return NULL;
623 	}
624 
625 	count = le32_to_cpu(pgpt_head->num_partition_entries) *
626 		le32_to_cpu(pgpt_head->sizeof_partition_entry);
627 
628 	debug("%s: count = %u * %u = %zu\n", __func__,
629 	      (u32) le32_to_cpu(pgpt_head->num_partition_entries),
630 	      (u32) le32_to_cpu(pgpt_head->sizeof_partition_entry), count);
631 
632 	/* Allocate memory for PTE, remember to FREE */
633 	if (count != 0) {
634 		pte = memalign(ARCH_DMA_MINALIGN,
635 			       PAD_TO_BLOCKSIZE(count, dev_desc));
636 	}
637 
638 	if (count == 0 || pte == NULL) {
639 		printf("%s: ERROR: Can't allocate 0x%zX "
640 		       "bytes for GPT Entries\n",
641 			__func__, count);
642 		return NULL;
643 	}
644 
645 	/* Read GPT Entries from device */
646 	blk_cnt = BLOCK_CNT(count, dev_desc);
647 	if (dev_desc->block_read (dev_desc->dev,
648 		(lbaint_t)le64_to_cpu(pgpt_head->partition_entry_lba),
649 		(lbaint_t) (blk_cnt), pte)
650 		!= blk_cnt) {
651 
652 		printf("*** ERROR: Can't read GPT Entries ***\n");
653 		free(pte);
654 		return NULL;
655 	}
656 	return pte;
657 }
658 
659 /**
660  * is_pte_valid(): validates a single Partition Table Entry
661  * @gpt_entry - Pointer to a single Partition Table Entry
662  *
663  * Description: returns 1 if valid,  0 on error.
664  */
665 static int is_pte_valid(gpt_entry * pte)
666 {
667 	efi_guid_t unused_guid;
668 
669 	if (!pte) {
670 		printf("%s: Invalid Argument(s)\n", __func__);
671 		return 0;
672 	}
673 
674 	/* Only one validation for now:
675 	 * The GUID Partition Type != Unused Entry (ALL-ZERO)
676 	 */
677 	memset(unused_guid.b, 0, sizeof(unused_guid.b));
678 
679 	if (memcmp(pte->partition_type_guid.b, unused_guid.b,
680 		sizeof(unused_guid.b)) == 0) {
681 
682 		debug("%s: Found an unused PTE GUID at 0x%08X\n", __func__,
683 		      (unsigned int)(uintptr_t)pte);
684 
685 		return 0;
686 	} else {
687 		return 1;
688 	}
689 }
690 #endif
691