xref: /openbmc/u-boot/disk/part_efi.c (revision 7ae350a0)
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 <inttypes.h>
18 #include <malloc.h>
19 #include <part_efi.h>
20 #include <linux/ctype.h>
21 
22 DECLARE_GLOBAL_DATA_PTR;
23 
24 #ifdef HAVE_BLOCK_DEVICE
25 /**
26  * efi_crc32() - EFI version of crc32 function
27  * @buf: buffer to calculate crc32 of
28  * @len - length of buf
29  *
30  * Description: Returns EFI-style CRC32 value for @buf
31  */
32 static inline u32 efi_crc32(const void *buf, u32 len)
33 {
34 	return crc32(0, buf, len);
35 }
36 
37 /*
38  * Private function prototypes
39  */
40 
41 static int pmbr_part_valid(struct partition *part);
42 static int is_pmbr_valid(legacy_mbr * mbr);
43 static int is_gpt_valid(block_dev_desc_t *dev_desc, u64 lba,
44 				gpt_header *pgpt_head, gpt_entry **pgpt_pte);
45 static gpt_entry *alloc_read_gpt_entries(block_dev_desc_t * dev_desc,
46 				gpt_header * pgpt_head);
47 static int is_pte_valid(gpt_entry * pte);
48 
49 static char *print_efiname(gpt_entry *pte)
50 {
51 	static char name[PARTNAME_SZ + 1];
52 	int i;
53 	for (i = 0; i < PARTNAME_SZ; i++) {
54 		u8 c;
55 		c = pte->partition_name[i] & 0xff;
56 		c = (c && !isprint(c)) ? '.' : c;
57 		name[i] = c;
58 	}
59 	name[PARTNAME_SZ] = 0;
60 	return name;
61 }
62 
63 static efi_guid_t system_guid = PARTITION_SYSTEM_GUID;
64 
65 static inline int is_bootable(gpt_entry *p)
66 {
67 	return p->attributes.fields.legacy_bios_bootable ||
68 		!memcmp(&(p->partition_type_guid), &system_guid,
69 			sizeof(efi_guid_t));
70 }
71 
72 #ifdef CONFIG_EFI_PARTITION
73 /*
74  * Public Functions (include/part.h)
75  */
76 
77 void print_part_efi(block_dev_desc_t * dev_desc)
78 {
79 	ALLOC_CACHE_ALIGN_BUFFER_PAD(gpt_header, gpt_head, 1, dev_desc->blksz);
80 	gpt_entry *gpt_pte = NULL;
81 	int i = 0;
82 	char uuid[37];
83 	unsigned char *uuid_bin;
84 
85 	if (!dev_desc) {
86 		printf("%s: Invalid Argument(s)\n", __func__);
87 		return;
88 	}
89 	/* This function validates AND fills in the GPT header and PTE */
90 	if (is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA,
91 			 gpt_head, &gpt_pte) != 1) {
92 		printf("%s: *** ERROR: Invalid GPT ***\n", __func__);
93 		if (is_gpt_valid(dev_desc, (dev_desc->lba - 1),
94 				 gpt_head, &gpt_pte) != 1) {
95 			printf("%s: *** ERROR: Invalid Backup GPT ***\n",
96 			       __func__);
97 			return;
98 		} else {
99 			printf("%s: ***        Using Backup GPT ***\n",
100 			       __func__);
101 		}
102 	}
103 
104 	debug("%s: gpt-entry at %p\n", __func__, gpt_pte);
105 
106 	printf("Part\tStart LBA\tEnd LBA\t\tName\n");
107 	printf("\tAttributes\n");
108 	printf("\tType GUID\n");
109 	printf("\tPartition GUID\n");
110 
111 	for (i = 0; i < le32_to_cpu(gpt_head->num_partition_entries); i++) {
112 		/* Stop at the first non valid PTE */
113 		if (!is_pte_valid(&gpt_pte[i]))
114 			break;
115 
116 		printf("%3d\t0x%08llx\t0x%08llx\t\"%s\"\n", (i + 1),
117 			le64_to_cpu(gpt_pte[i].starting_lba),
118 			le64_to_cpu(gpt_pte[i].ending_lba),
119 			print_efiname(&gpt_pte[i]));
120 		printf("\tattrs:\t0x%016llx\n", gpt_pte[i].attributes.raw);
121 		uuid_bin = (unsigned char *)gpt_pte[i].partition_type_guid.b;
122 		uuid_bin_to_str(uuid_bin, uuid, UUID_STR_FORMAT_GUID);
123 		printf("\ttype:\t%s\n", uuid);
124 		uuid_bin = (unsigned char *)gpt_pte[i].unique_partition_guid.b;
125 		uuid_bin_to_str(uuid_bin, uuid, UUID_STR_FORMAT_GUID);
126 		printf("\tguid:\t%s\n", uuid);
127 	}
128 
129 	/* Remember to free pte */
130 	free(gpt_pte);
131 	return;
132 }
133 
134 int get_partition_info_efi(block_dev_desc_t * dev_desc, int part,
135 				disk_partition_t * info)
136 {
137 	ALLOC_CACHE_ALIGN_BUFFER_PAD(gpt_header, gpt_head, 1, dev_desc->blksz);
138 	gpt_entry *gpt_pte = NULL;
139 
140 	/* "part" argument must be at least 1 */
141 	if (!dev_desc || !info || part < 1) {
142 		printf("%s: Invalid Argument(s)\n", __func__);
143 		return -1;
144 	}
145 
146 	/* This function validates AND fills in the GPT header and PTE */
147 	if (is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA,
148 			gpt_head, &gpt_pte) != 1) {
149 		printf("%s: *** ERROR: Invalid GPT ***\n", __func__);
150 		if (is_gpt_valid(dev_desc, (dev_desc->lba - 1),
151 				 gpt_head, &gpt_pte) != 1) {
152 			printf("%s: *** ERROR: Invalid Backup GPT ***\n",
153 			       __func__);
154 			return -1;
155 		} else {
156 			printf("%s: ***        Using Backup GPT ***\n",
157 			       __func__);
158 		}
159 	}
160 
161 	if (part > le32_to_cpu(gpt_head->num_partition_entries) ||
162 	    !is_pte_valid(&gpt_pte[part - 1])) {
163 		debug("%s: *** ERROR: Invalid partition number %d ***\n",
164 			__func__, part);
165 		free(gpt_pte);
166 		return -1;
167 	}
168 
169 	/* The 'lbaint_t' casting may limit the maximum disk size to 2 TB */
170 	info->start = (lbaint_t)le64_to_cpu(gpt_pte[part - 1].starting_lba);
171 	/* The ending LBA is inclusive, to calculate size, add 1 to it */
172 	info->size = (lbaint_t)le64_to_cpu(gpt_pte[part - 1].ending_lba) + 1
173 		     - info->start;
174 	info->blksz = dev_desc->blksz;
175 
176 	sprintf((char *)info->name, "%s",
177 			print_efiname(&gpt_pte[part - 1]));
178 	sprintf((char *)info->type, "U-Boot");
179 	info->bootable = is_bootable(&gpt_pte[part - 1]);
180 #ifdef CONFIG_PARTITION_UUIDS
181 	uuid_bin_to_str(gpt_pte[part - 1].unique_partition_guid.b, info->uuid,
182 			UUID_STR_FORMAT_GUID);
183 #endif
184 
185 	debug("%s: start 0x" LBAF ", size 0x" LBAF ", name %s\n", __func__,
186 	      info->start, info->size, info->name);
187 
188 	/* Remember to free pte */
189 	free(gpt_pte);
190 	return 0;
191 }
192 
193 int get_partition_info_efi_by_name(block_dev_desc_t *dev_desc,
194 	const char *name, disk_partition_t *info)
195 {
196 	int ret;
197 	int i;
198 	for (i = 1; i < GPT_ENTRY_NUMBERS; i++) {
199 		ret = get_partition_info_efi(dev_desc, i, info);
200 		if (ret != 0) {
201 			/* no more entries in table */
202 			return -1;
203 		}
204 		if (strcmp(name, (const char *)info->name) == 0) {
205 			/* matched */
206 			return 0;
207 		}
208 	}
209 	return -2;
210 }
211 
212 int test_part_efi(block_dev_desc_t * dev_desc)
213 {
214 	ALLOC_CACHE_ALIGN_BUFFER_PAD(legacy_mbr, legacymbr, 1, dev_desc->blksz);
215 
216 	/* Read legacy MBR from block 0 and validate it */
217 	if ((dev_desc->block_read(dev_desc->dev, 0, 1, (ulong *)legacymbr) != 1)
218 		|| (is_pmbr_valid(legacymbr) != 1)) {
219 		return -1;
220 	}
221 	return 0;
222 }
223 
224 /**
225  * set_protective_mbr(): Set the EFI protective MBR
226  * @param dev_desc - block device descriptor
227  *
228  * @return - zero on success, otherwise error
229  */
230 static int set_protective_mbr(block_dev_desc_t *dev_desc)
231 {
232 	/* Setup the Protective MBR */
233 	ALLOC_CACHE_ALIGN_BUFFER(legacy_mbr, p_mbr, 1);
234 	memset(p_mbr, 0, sizeof(*p_mbr));
235 
236 	if (p_mbr == NULL) {
237 		printf("%s: calloc failed!\n", __func__);
238 		return -1;
239 	}
240 	/* Append signature */
241 	p_mbr->signature = MSDOS_MBR_SIGNATURE;
242 	p_mbr->partition_record[0].sys_ind = EFI_PMBR_OSTYPE_EFI_GPT;
243 	p_mbr->partition_record[0].start_sect = 1;
244 	p_mbr->partition_record[0].nr_sects = (u32) dev_desc->lba;
245 
246 	/* Write MBR sector to the MMC device */
247 	if (dev_desc->block_write(dev_desc->dev, 0, 1, p_mbr) != 1) {
248 		printf("** Can't write to device %d **\n",
249 			dev_desc->dev);
250 		return -1;
251 	}
252 
253 	return 0;
254 }
255 
256 int write_gpt_table(block_dev_desc_t *dev_desc,
257 		gpt_header *gpt_h, gpt_entry *gpt_e)
258 {
259 	const int pte_blk_cnt = BLOCK_CNT((gpt_h->num_partition_entries
260 					   * sizeof(gpt_entry)), dev_desc);
261 	u32 calc_crc32;
262 	u64 val;
263 
264 	debug("max lba: %x\n", (u32) dev_desc->lba);
265 	/* Setup the Protective MBR */
266 	if (set_protective_mbr(dev_desc) < 0)
267 		goto err;
268 
269 	/* Generate CRC for the Primary GPT Header */
270 	calc_crc32 = efi_crc32((const unsigned char *)gpt_e,
271 			      le32_to_cpu(gpt_h->num_partition_entries) *
272 			      le32_to_cpu(gpt_h->sizeof_partition_entry));
273 	gpt_h->partition_entry_array_crc32 = cpu_to_le32(calc_crc32);
274 
275 	calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
276 			      le32_to_cpu(gpt_h->header_size));
277 	gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
278 
279 	/* Write the First GPT to the block right after the Legacy MBR */
280 	if (dev_desc->block_write(dev_desc->dev, 1, 1, gpt_h) != 1)
281 		goto err;
282 
283 	if (dev_desc->block_write(dev_desc->dev, 2, pte_blk_cnt, gpt_e)
284 	    != pte_blk_cnt)
285 		goto err;
286 
287 	/* recalculate the values for the Backup GPT Header */
288 	val = le64_to_cpu(gpt_h->my_lba);
289 	gpt_h->my_lba = gpt_h->alternate_lba;
290 	gpt_h->alternate_lba = cpu_to_le64(val);
291 	gpt_h->header_crc32 = 0;
292 
293 	calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
294 			      le32_to_cpu(gpt_h->header_size));
295 	gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
296 
297 	if (dev_desc->block_write(dev_desc->dev,
298 				  (lbaint_t)le64_to_cpu(gpt_h->last_usable_lba)
299 				  + 1,
300 				  pte_blk_cnt, gpt_e) != pte_blk_cnt)
301 		goto err;
302 
303 	if (dev_desc->block_write(dev_desc->dev,
304 				  (lbaint_t)le64_to_cpu(gpt_h->my_lba), 1,
305 				  gpt_h) != 1)
306 		goto err;
307 
308 	debug("GPT successfully written to block device!\n");
309 	return 0;
310 
311  err:
312 	printf("** Can't write to device %d **\n", dev_desc->dev);
313 	return -1;
314 }
315 
316 int gpt_fill_pte(gpt_header *gpt_h, gpt_entry *gpt_e,
317 		disk_partition_t *partitions, int parts)
318 {
319 	lbaint_t offset = (lbaint_t)le64_to_cpu(gpt_h->first_usable_lba);
320 	lbaint_t start;
321 	lbaint_t last_usable_lba = (lbaint_t)
322 			le64_to_cpu(gpt_h->last_usable_lba);
323 	int i, k;
324 	size_t efiname_len, dosname_len;
325 #ifdef CONFIG_PARTITION_UUIDS
326 	char *str_uuid;
327 	unsigned char *bin_uuid;
328 #endif
329 
330 	for (i = 0; i < parts; i++) {
331 		/* partition starting lba */
332 		start = partitions[i].start;
333 		if (start && (start < offset)) {
334 			printf("Partition overlap\n");
335 			return -1;
336 		}
337 		if (start) {
338 			gpt_e[i].starting_lba = cpu_to_le64(start);
339 			offset = start + partitions[i].size;
340 		} else {
341 			gpt_e[i].starting_lba = cpu_to_le64(offset);
342 			offset += partitions[i].size;
343 		}
344 		if (offset >= last_usable_lba) {
345 			printf("Partitions layout exceds disk size\n");
346 			return -1;
347 		}
348 		/* partition ending lba */
349 		if ((i == parts - 1) && (partitions[i].size == 0))
350 			/* extend the last partition to maximuim */
351 			gpt_e[i].ending_lba = gpt_h->last_usable_lba;
352 		else
353 			gpt_e[i].ending_lba = cpu_to_le64(offset - 1);
354 
355 		/* partition type GUID */
356 		memcpy(gpt_e[i].partition_type_guid.b,
357 			&PARTITION_BASIC_DATA_GUID, 16);
358 
359 #ifdef CONFIG_PARTITION_UUIDS
360 		str_uuid = partitions[i].uuid;
361 		bin_uuid = gpt_e[i].unique_partition_guid.b;
362 
363 		if (uuid_str_to_bin(str_uuid, bin_uuid, UUID_STR_FORMAT_STD)) {
364 			printf("Partition no. %d: invalid guid: %s\n",
365 				i, str_uuid);
366 			return -1;
367 		}
368 #endif
369 
370 		/* partition attributes */
371 		memset(&gpt_e[i].attributes, 0,
372 		       sizeof(gpt_entry_attributes));
373 
374 		/* partition name */
375 		efiname_len = sizeof(gpt_e[i].partition_name)
376 			/ sizeof(efi_char16_t);
377 		dosname_len = sizeof(partitions[i].name);
378 
379 		memset(gpt_e[i].partition_name, 0,
380 		       sizeof(gpt_e[i].partition_name));
381 
382 		for (k = 0; k < min(dosname_len, efiname_len); k++)
383 			gpt_e[i].partition_name[k] =
384 				(efi_char16_t)(partitions[i].name[k]);
385 
386 		debug("%s: name: %s offset[%d]: 0x" LBAF
387 		      " size[%d]: 0x" LBAF "\n",
388 		      __func__, partitions[i].name, i,
389 		      offset, i, partitions[i].size);
390 	}
391 
392 	return 0;
393 }
394 
395 int gpt_fill_header(block_dev_desc_t *dev_desc, gpt_header *gpt_h,
396 		char *str_guid, int parts_count)
397 {
398 	gpt_h->signature = cpu_to_le64(GPT_HEADER_SIGNATURE);
399 	gpt_h->revision = cpu_to_le32(GPT_HEADER_REVISION_V1);
400 	gpt_h->header_size = cpu_to_le32(sizeof(gpt_header));
401 	gpt_h->my_lba = cpu_to_le64(1);
402 	gpt_h->alternate_lba = cpu_to_le64(dev_desc->lba - 1);
403 	gpt_h->first_usable_lba = cpu_to_le64(34);
404 	gpt_h->last_usable_lba = cpu_to_le64(dev_desc->lba - 34);
405 	gpt_h->partition_entry_lba = cpu_to_le64(2);
406 	gpt_h->num_partition_entries = cpu_to_le32(GPT_ENTRY_NUMBERS);
407 	gpt_h->sizeof_partition_entry = cpu_to_le32(sizeof(gpt_entry));
408 	gpt_h->header_crc32 = 0;
409 	gpt_h->partition_entry_array_crc32 = 0;
410 
411 	if (uuid_str_to_bin(str_guid, gpt_h->disk_guid.b, UUID_STR_FORMAT_GUID))
412 		return -1;
413 
414 	return 0;
415 }
416 
417 int gpt_restore(block_dev_desc_t *dev_desc, char *str_disk_guid,
418 		disk_partition_t *partitions, int parts_count)
419 {
420 	int ret;
421 
422 	gpt_header *gpt_h = calloc(1, PAD_TO_BLOCKSIZE(sizeof(gpt_header),
423 						       dev_desc));
424 	gpt_entry *gpt_e;
425 
426 	if (gpt_h == NULL) {
427 		printf("%s: calloc failed!\n", __func__);
428 		return -1;
429 	}
430 
431 	gpt_e = calloc(1, PAD_TO_BLOCKSIZE(GPT_ENTRY_NUMBERS
432 					       * sizeof(gpt_entry),
433 					       dev_desc));
434 	if (gpt_e == NULL) {
435 		printf("%s: calloc failed!\n", __func__);
436 		free(gpt_h);
437 		return -1;
438 	}
439 
440 	/* Generate Primary GPT header (LBA1) */
441 	ret = gpt_fill_header(dev_desc, gpt_h, str_disk_guid, parts_count);
442 	if (ret)
443 		goto err;
444 
445 	/* Generate partition entries */
446 	ret = gpt_fill_pte(gpt_h, gpt_e, partitions, parts_count);
447 	if (ret)
448 		goto err;
449 
450 	/* Write GPT partition table */
451 	ret = write_gpt_table(dev_desc, gpt_h, gpt_e);
452 
453 err:
454 	free(gpt_e);
455 	free(gpt_h);
456 	return ret;
457 }
458 #endif
459 
460 /*
461  * Private functions
462  */
463 /*
464  * pmbr_part_valid(): Check for EFI partition signature
465  *
466  * Returns: 1 if EFI GPT partition type is found.
467  */
468 static int pmbr_part_valid(struct partition *part)
469 {
470 	if (part->sys_ind == EFI_PMBR_OSTYPE_EFI_GPT &&
471 		get_unaligned_le32(&part->start_sect) == 1UL) {
472 		return 1;
473 	}
474 
475 	return 0;
476 }
477 
478 /*
479  * is_pmbr_valid(): test Protective MBR for validity
480  *
481  * Returns: 1 if PMBR is valid, 0 otherwise.
482  * Validity depends on two things:
483  *  1) MSDOS signature is in the last two bytes of the MBR
484  *  2) One partition of type 0xEE is found, checked by pmbr_part_valid()
485  */
486 static int is_pmbr_valid(legacy_mbr * mbr)
487 {
488 	int i = 0;
489 
490 	if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
491 		return 0;
492 
493 	for (i = 0; i < 4; i++) {
494 		if (pmbr_part_valid(&mbr->partition_record[i])) {
495 			return 1;
496 		}
497 	}
498 	return 0;
499 }
500 
501 /**
502  * is_gpt_valid() - tests one GPT header and PTEs for validity
503  *
504  * lba is the logical block address of the GPT header to test
505  * gpt is a GPT header ptr, filled on return.
506  * ptes is a PTEs ptr, filled on return.
507  *
508  * Description: returns 1 if valid,  0 on error.
509  * If valid, returns pointers to PTEs.
510  */
511 static int is_gpt_valid(block_dev_desc_t *dev_desc, u64 lba,
512 			gpt_header *pgpt_head, gpt_entry **pgpt_pte)
513 {
514 	u32 crc32_backup = 0;
515 	u32 calc_crc32;
516 	u64 lastlba;
517 
518 	if (!dev_desc || !pgpt_head) {
519 		printf("%s: Invalid Argument(s)\n", __func__);
520 		return 0;
521 	}
522 
523 	/* Read GPT Header from device */
524 	if (dev_desc->block_read(dev_desc->dev, (lbaint_t)lba, 1, pgpt_head)
525 			!= 1) {
526 		printf("*** ERROR: Can't read GPT header ***\n");
527 		return 0;
528 	}
529 
530 	/* Check the GPT header signature */
531 	if (le64_to_cpu(pgpt_head->signature) != GPT_HEADER_SIGNATURE) {
532 		printf("GUID Partition Table Header signature is wrong:"
533 			"0x%llX != 0x%llX\n",
534 			le64_to_cpu(pgpt_head->signature),
535 			GPT_HEADER_SIGNATURE);
536 		return 0;
537 	}
538 
539 	/* Check the GUID Partition Table CRC */
540 	memcpy(&crc32_backup, &pgpt_head->header_crc32, sizeof(crc32_backup));
541 	memset(&pgpt_head->header_crc32, 0, sizeof(pgpt_head->header_crc32));
542 
543 	calc_crc32 = efi_crc32((const unsigned char *)pgpt_head,
544 		le32_to_cpu(pgpt_head->header_size));
545 
546 	memcpy(&pgpt_head->header_crc32, &crc32_backup, sizeof(crc32_backup));
547 
548 	if (calc_crc32 != le32_to_cpu(crc32_backup)) {
549 		printf("GUID Partition Table Header CRC is wrong:"
550 			"0x%x != 0x%x\n",
551 		       le32_to_cpu(crc32_backup), calc_crc32);
552 		return 0;
553 	}
554 
555 	/* Check that the my_lba entry points to the LBA that contains the GPT */
556 	if (le64_to_cpu(pgpt_head->my_lba) != lba) {
557 		printf("GPT: my_lba incorrect: %llX != %" PRIX64 "\n",
558 		       le64_to_cpu(pgpt_head->my_lba),
559 		       lba);
560 		return 0;
561 	}
562 
563 	/* Check the first_usable_lba and last_usable_lba are within the disk. */
564 	lastlba = (u64)dev_desc->lba;
565 	if (le64_to_cpu(pgpt_head->first_usable_lba) > lastlba) {
566 		printf("GPT: first_usable_lba incorrect: %llX > %" PRIX64 "\n",
567 		       le64_to_cpu(pgpt_head->first_usable_lba), lastlba);
568 		return 0;
569 	}
570 	if (le64_to_cpu(pgpt_head->last_usable_lba) > lastlba) {
571 		printf("GPT: last_usable_lba incorrect: %llX > %" PRIX64 "\n",
572 		       le64_to_cpu(pgpt_head->last_usable_lba), lastlba);
573 		return 0;
574 	}
575 
576 	debug("GPT: first_usable_lba: %llX last_usable_lba %llX last lba %"
577 	      PRIX64 "\n", le64_to_cpu(pgpt_head->first_usable_lba),
578 	      le64_to_cpu(pgpt_head->last_usable_lba), lastlba);
579 
580 	/* Read and allocate Partition Table Entries */
581 	*pgpt_pte = alloc_read_gpt_entries(dev_desc, pgpt_head);
582 	if (*pgpt_pte == NULL) {
583 		printf("GPT: Failed to allocate memory for PTE\n");
584 		return 0;
585 	}
586 
587 	/* Check the GUID Partition Table Entry Array CRC */
588 	calc_crc32 = efi_crc32((const unsigned char *)*pgpt_pte,
589 		le32_to_cpu(pgpt_head->num_partition_entries) *
590 		le32_to_cpu(pgpt_head->sizeof_partition_entry));
591 
592 	if (calc_crc32 != le32_to_cpu(pgpt_head->partition_entry_array_crc32)) {
593 		printf("GUID Partition Table Entry Array CRC is wrong:"
594 			"0x%x != 0x%x\n",
595 			le32_to_cpu(pgpt_head->partition_entry_array_crc32),
596 			calc_crc32);
597 
598 		free(*pgpt_pte);
599 		return 0;
600 	}
601 
602 	/* We're done, all's well */
603 	return 1;
604 }
605 
606 /**
607  * alloc_read_gpt_entries(): reads partition entries from disk
608  * @dev_desc
609  * @gpt - GPT header
610  *
611  * Description: Returns ptes on success,  NULL on error.
612  * Allocates space for PTEs based on information found in @gpt.
613  * Notes: remember to free pte when you're done!
614  */
615 static gpt_entry *alloc_read_gpt_entries(block_dev_desc_t * dev_desc,
616 					 gpt_header * pgpt_head)
617 {
618 	size_t count = 0, blk_cnt;
619 	gpt_entry *pte = NULL;
620 
621 	if (!dev_desc || !pgpt_head) {
622 		printf("%s: Invalid Argument(s)\n", __func__);
623 		return NULL;
624 	}
625 
626 	count = le32_to_cpu(pgpt_head->num_partition_entries) *
627 		le32_to_cpu(pgpt_head->sizeof_partition_entry);
628 
629 	debug("%s: count = %u * %u = %zu\n", __func__,
630 	      (u32) le32_to_cpu(pgpt_head->num_partition_entries),
631 	      (u32) le32_to_cpu(pgpt_head->sizeof_partition_entry), count);
632 
633 	/* Allocate memory for PTE, remember to FREE */
634 	if (count != 0) {
635 		pte = memalign(ARCH_DMA_MINALIGN,
636 			       PAD_TO_BLOCKSIZE(count, dev_desc));
637 	}
638 
639 	if (count == 0 || pte == NULL) {
640 		printf("%s: ERROR: Can't allocate 0x%zX "
641 		       "bytes for GPT Entries\n",
642 			__func__, count);
643 		return NULL;
644 	}
645 
646 	/* Read GPT Entries from device */
647 	blk_cnt = BLOCK_CNT(count, dev_desc);
648 	if (dev_desc->block_read (dev_desc->dev,
649 		(lbaint_t)le64_to_cpu(pgpt_head->partition_entry_lba),
650 		(lbaint_t) (blk_cnt), pte)
651 		!= blk_cnt) {
652 
653 		printf("*** ERROR: Can't read GPT Entries ***\n");
654 		free(pte);
655 		return NULL;
656 	}
657 	return pte;
658 }
659 
660 /**
661  * is_pte_valid(): validates a single Partition Table Entry
662  * @gpt_entry - Pointer to a single Partition Table Entry
663  *
664  * Description: returns 1 if valid,  0 on error.
665  */
666 static int is_pte_valid(gpt_entry * pte)
667 {
668 	efi_guid_t unused_guid;
669 
670 	if (!pte) {
671 		printf("%s: Invalid Argument(s)\n", __func__);
672 		return 0;
673 	}
674 
675 	/* Only one validation for now:
676 	 * The GUID Partition Type != Unused Entry (ALL-ZERO)
677 	 */
678 	memset(unused_guid.b, 0, sizeof(unused_guid.b));
679 
680 	if (memcmp(pte->partition_type_guid.b, unused_guid.b,
681 		sizeof(unused_guid.b)) == 0) {
682 
683 		debug("%s: Found an unused PTE GUID at 0x%08X\n", __func__,
684 		      (unsigned int)(uintptr_t)pte);
685 
686 		return 0;
687 	} else {
688 		return 1;
689 	}
690 }
691 #endif
692