xref: /openbmc/u-boot/disk/part_efi.c (revision da4105df)
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  * Problems with CONFIG_SYS_64BIT_LBA:
10  *
11  * struct disk_partition.start in include/part.h is sized as ulong.
12  * When CONFIG_SYS_64BIT_LBA is activated, lbaint_t changes from ulong to uint64_t.
13  * For now, it is cast back to ulong at assignment.
14  *
15  * This limits the maximum size of addressable storage to < 2 Terra Bytes
16  */
17 #include <asm/unaligned.h>
18 #include <common.h>
19 #include <command.h>
20 #include <ide.h>
21 #include <malloc.h>
22 #include <part_efi.h>
23 #include <linux/ctype.h>
24 
25 DECLARE_GLOBAL_DATA_PTR;
26 
27 #ifdef HAVE_BLOCK_DEVICE
28 /**
29  * efi_crc32() - EFI version of crc32 function
30  * @buf: buffer to calculate crc32 of
31  * @len - length of buf
32  *
33  * Description: Returns EFI-style CRC32 value for @buf
34  */
35 static inline u32 efi_crc32(const void *buf, u32 len)
36 {
37 	return crc32(0, buf, len);
38 }
39 
40 /*
41  * Private function prototypes
42  */
43 
44 static int pmbr_part_valid(struct partition *part);
45 static int is_pmbr_valid(legacy_mbr * mbr);
46 static int is_gpt_valid(block_dev_desc_t * dev_desc, unsigned long long lba,
47 				gpt_header * pgpt_head, gpt_entry ** pgpt_pte);
48 static gpt_entry *alloc_read_gpt_entries(block_dev_desc_t * dev_desc,
49 				gpt_header * pgpt_head);
50 static int is_pte_valid(gpt_entry * pte);
51 
52 static char *print_efiname(gpt_entry *pte)
53 {
54 	static char name[PARTNAME_SZ + 1];
55 	int i;
56 	for (i = 0; i < PARTNAME_SZ; i++) {
57 		u8 c;
58 		c = pte->partition_name[i] & 0xff;
59 		c = (c && !isprint(c)) ? '.' : c;
60 		name[i] = c;
61 	}
62 	name[PARTNAME_SZ] = 0;
63 	return name;
64 }
65 
66 static void uuid_string(unsigned char *uuid, char *str)
67 {
68 	static const u8 le[16] = {3, 2, 1, 0, 5, 4, 7, 6, 8, 9, 10, 11,
69 				  12, 13, 14, 15};
70 	int i;
71 
72 	for (i = 0; i < 16; i++) {
73 		sprintf(str, "%02x", uuid[le[i]]);
74 		str += 2;
75 		switch (i) {
76 		case 3:
77 		case 5:
78 		case 7:
79 		case 9:
80 			*str++ = '-';
81 			break;
82 		}
83 	}
84 }
85 
86 static efi_guid_t system_guid = PARTITION_SYSTEM_GUID;
87 
88 static inline int is_bootable(gpt_entry *p)
89 {
90 	return p->attributes.fields.legacy_bios_bootable ||
91 		!memcmp(&(p->partition_type_guid), &system_guid,
92 			sizeof(efi_guid_t));
93 }
94 
95 #ifdef CONFIG_EFI_PARTITION
96 /*
97  * Public Functions (include/part.h)
98  */
99 
100 void print_part_efi(block_dev_desc_t * dev_desc)
101 {
102 	ALLOC_CACHE_ALIGN_BUFFER_PAD(gpt_header, gpt_head, 1, dev_desc->blksz);
103 	gpt_entry *gpt_pte = NULL;
104 	int i = 0;
105 	char uuid[37];
106 
107 	if (!dev_desc) {
108 		printf("%s: Invalid Argument(s)\n", __func__);
109 		return;
110 	}
111 	/* This function validates AND fills in the GPT header and PTE */
112 	if (is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA,
113 			 gpt_head, &gpt_pte) != 1) {
114 		printf("%s: *** ERROR: Invalid GPT ***\n", __func__);
115 		return;
116 	}
117 
118 	debug("%s: gpt-entry at %p\n", __func__, gpt_pte);
119 
120 	printf("Part\tStart LBA\tEnd LBA\t\tName\n");
121 	printf("\tAttributes\n");
122 	printf("\tType UUID\n");
123 	printf("\tPartition UUID\n");
124 
125 	for (i = 0; i < le32_to_cpu(gpt_head->num_partition_entries); i++) {
126 		/* Stop at the first non valid PTE */
127 		if (!is_pte_valid(&gpt_pte[i]))
128 			break;
129 
130 		printf("%3d\t0x%08llx\t0x%08llx\t\"%s\"\n", (i + 1),
131 			le64_to_cpu(gpt_pte[i].starting_lba),
132 			le64_to_cpu(gpt_pte[i].ending_lba),
133 			print_efiname(&gpt_pte[i]));
134 		printf("\tattrs:\t0x%016llx\n", gpt_pte[i].attributes.raw);
135 		uuid_string(gpt_pte[i].partition_type_guid.b, uuid);
136 		printf("\ttype:\t%s\n", uuid);
137 		uuid_string(gpt_pte[i].unique_partition_guid.b, uuid);
138 		printf("\tuuid:\t%s\n", uuid);
139 	}
140 
141 	/* Remember to free pte */
142 	free(gpt_pte);
143 	return;
144 }
145 
146 int get_partition_info_efi(block_dev_desc_t * dev_desc, int part,
147 				disk_partition_t * info)
148 {
149 	ALLOC_CACHE_ALIGN_BUFFER_PAD(gpt_header, gpt_head, 1, dev_desc->blksz);
150 	gpt_entry *gpt_pte = NULL;
151 
152 	/* "part" argument must be at least 1 */
153 	if (!dev_desc || !info || part < 1) {
154 		printf("%s: Invalid Argument(s)\n", __func__);
155 		return -1;
156 	}
157 
158 	/* This function validates AND fills in the GPT header and PTE */
159 	if (is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA,
160 			gpt_head, &gpt_pte) != 1) {
161 		printf("%s: *** ERROR: Invalid GPT ***\n", __func__);
162 		return -1;
163 	}
164 
165 	if (part > le32_to_cpu(gpt_head->num_partition_entries) ||
166 	    !is_pte_valid(&gpt_pte[part - 1])) {
167 		debug("%s: *** ERROR: Invalid partition number %d ***\n",
168 			__func__, part);
169 		free(gpt_pte);
170 		return -1;
171 	}
172 
173 	/* The ulong casting limits the maximum disk size to 2 TB */
174 	info->start = (u64)le64_to_cpu(gpt_pte[part - 1].starting_lba);
175 	/* The ending LBA is inclusive, to calculate size, add 1 to it */
176 	info->size = ((u64)le64_to_cpu(gpt_pte[part - 1].ending_lba) + 1)
177 		     - info->start;
178 	info->blksz = dev_desc->blksz;
179 
180 	sprintf((char *)info->name, "%s",
181 			print_efiname(&gpt_pte[part - 1]));
182 	sprintf((char *)info->type, "U-Boot");
183 	info->bootable = is_bootable(&gpt_pte[part - 1]);
184 #ifdef CONFIG_PARTITION_UUIDS
185 	uuid_string(gpt_pte[part - 1].unique_partition_guid.b, info->uuid);
186 #endif
187 
188 	debug("%s: start 0x" LBAF ", size 0x" LBAF ", name %s", __func__,
189 	      info->start, info->size, info->name);
190 
191 	/* Remember to free pte */
192 	free(gpt_pte);
193 	return 0;
194 }
195 
196 int test_part_efi(block_dev_desc_t * dev_desc)
197 {
198 	ALLOC_CACHE_ALIGN_BUFFER_PAD(legacy_mbr, legacymbr, 1, dev_desc->blksz);
199 
200 	/* Read legacy MBR from block 0 and validate it */
201 	if ((dev_desc->block_read(dev_desc->dev, 0, 1, (ulong *)legacymbr) != 1)
202 		|| (is_pmbr_valid(legacymbr) != 1)) {
203 		return -1;
204 	}
205 	return 0;
206 }
207 
208 /**
209  * set_protective_mbr(): Set the EFI protective MBR
210  * @param dev_desc - block device descriptor
211  *
212  * @return - zero on success, otherwise error
213  */
214 static int set_protective_mbr(block_dev_desc_t *dev_desc)
215 {
216 	legacy_mbr *p_mbr;
217 
218 	/* Setup the Protective MBR */
219 	p_mbr = calloc(1, sizeof(p_mbr));
220 	if (p_mbr == NULL) {
221 		printf("%s: calloc failed!\n", __func__);
222 		return -1;
223 	}
224 	/* Append signature */
225 	p_mbr->signature = MSDOS_MBR_SIGNATURE;
226 	p_mbr->partition_record[0].sys_ind = EFI_PMBR_OSTYPE_EFI_GPT;
227 	p_mbr->partition_record[0].start_sect = 1;
228 	p_mbr->partition_record[0].nr_sects = (u32) dev_desc->lba;
229 
230 	/* Write MBR sector to the MMC device */
231 	if (dev_desc->block_write(dev_desc->dev, 0, 1, p_mbr) != 1) {
232 		printf("** Can't write to device %d **\n",
233 			dev_desc->dev);
234 		free(p_mbr);
235 		return -1;
236 	}
237 
238 	free(p_mbr);
239 	return 0;
240 }
241 
242 /**
243  * string_uuid(); Convert UUID stored as string to bytes
244  *
245  * @param uuid - UUID represented as string
246  * @param dst - GUID buffer
247  *
248  * @return return 0 on successful conversion
249  */
250 static int string_uuid(char *uuid, u8 *dst)
251 {
252 	efi_guid_t guid;
253 	u16 b, c, d;
254 	u64 e;
255 	u32 a;
256 	u8 *p;
257 	u8 i;
258 
259 	const u8 uuid_str_len = 36;
260 
261 	/* The UUID is written in text: */
262 	/* 1        9    14   19   24 */
263 	/* xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx */
264 
265 	debug("%s: uuid: %s\n", __func__, uuid);
266 
267 	if (strlen(uuid) != uuid_str_len)
268 		return -1;
269 
270 	for (i = 0; i < uuid_str_len; i++) {
271 		if ((i == 8) || (i == 13) || (i == 18) || (i == 23)) {
272 			if (uuid[i] != '-')
273 				return -1;
274 		} else {
275 			if (!isxdigit(uuid[i]))
276 				return -1;
277 		}
278 	}
279 
280 	a = (u32)simple_strtoul(uuid, NULL, 16);
281 	b = (u16)simple_strtoul(uuid + 9, NULL, 16);
282 	c = (u16)simple_strtoul(uuid + 14, NULL, 16);
283 	d = (u16)simple_strtoul(uuid + 19, NULL, 16);
284 	e = (u64)simple_strtoull(uuid + 24, NULL, 16);
285 
286 	p = (u8 *) &e;
287 	guid = EFI_GUID(a, b, c, d >> 8, d & 0xFF,
288 			*(p + 5), *(p + 4), *(p + 3),
289 			*(p + 2), *(p + 1) , *p);
290 
291 	memcpy(dst, guid.b, sizeof(efi_guid_t));
292 
293 	return 0;
294 }
295 
296 int write_gpt_table(block_dev_desc_t *dev_desc,
297 		gpt_header *gpt_h, gpt_entry *gpt_e)
298 {
299 	const int pte_blk_cnt = BLOCK_CNT((gpt_h->num_partition_entries
300 					   * sizeof(gpt_entry)), dev_desc);
301 	u32 calc_crc32;
302 	u64 val;
303 
304 	debug("max lba: %x\n", (u32) dev_desc->lba);
305 	/* Setup the Protective MBR */
306 	if (set_protective_mbr(dev_desc) < 0)
307 		goto err;
308 
309 	/* Generate CRC for the Primary GPT Header */
310 	calc_crc32 = efi_crc32((const unsigned char *)gpt_e,
311 			      le32_to_cpu(gpt_h->num_partition_entries) *
312 			      le32_to_cpu(gpt_h->sizeof_partition_entry));
313 	gpt_h->partition_entry_array_crc32 = cpu_to_le32(calc_crc32);
314 
315 	calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
316 			      le32_to_cpu(gpt_h->header_size));
317 	gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
318 
319 	/* Write the First GPT to the block right after the Legacy MBR */
320 	if (dev_desc->block_write(dev_desc->dev, 1, 1, gpt_h) != 1)
321 		goto err;
322 
323 	if (dev_desc->block_write(dev_desc->dev, 2, pte_blk_cnt, gpt_e)
324 	    != pte_blk_cnt)
325 		goto err;
326 
327 	/* recalculate the values for the Second GPT Header */
328 	val = le64_to_cpu(gpt_h->my_lba);
329 	gpt_h->my_lba = gpt_h->alternate_lba;
330 	gpt_h->alternate_lba = cpu_to_le64(val);
331 	gpt_h->header_crc32 = 0;
332 
333 	calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
334 			      le32_to_cpu(gpt_h->header_size));
335 	gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
336 
337 	if (dev_desc->block_write(dev_desc->dev,
338 				  le32_to_cpu(gpt_h->last_usable_lba + 1),
339 				  pte_blk_cnt, gpt_e) != pte_blk_cnt)
340 		goto err;
341 
342 	if (dev_desc->block_write(dev_desc->dev,
343 				  le32_to_cpu(gpt_h->my_lba), 1, gpt_h) != 1)
344 		goto err;
345 
346 	debug("GPT successfully written to block device!\n");
347 	return 0;
348 
349  err:
350 	printf("** Can't write to device %d **\n", dev_desc->dev);
351 	return -1;
352 }
353 
354 int gpt_fill_pte(gpt_header *gpt_h, gpt_entry *gpt_e,
355 		disk_partition_t *partitions, int parts)
356 {
357 	u32 offset = (u32)le32_to_cpu(gpt_h->first_usable_lba);
358 	ulong start;
359 	int i, k;
360 	size_t efiname_len, dosname_len;
361 #ifdef CONFIG_PARTITION_UUIDS
362 	char *str_uuid;
363 #endif
364 
365 	for (i = 0; i < parts; i++) {
366 		/* partition starting lba */
367 		start = partitions[i].start;
368 		if (start && (start < offset)) {
369 			printf("Partition overlap\n");
370 			return -1;
371 		}
372 		if (start) {
373 			gpt_e[i].starting_lba = cpu_to_le64(start);
374 			offset = start + partitions[i].size;
375 		} else {
376 			gpt_e[i].starting_lba = cpu_to_le64(offset);
377 			offset += partitions[i].size;
378 		}
379 		if (offset >= gpt_h->last_usable_lba) {
380 			printf("Partitions layout exceds disk size\n");
381 			return -1;
382 		}
383 		/* partition ending lba */
384 		if ((i == parts - 1) && (partitions[i].size == 0))
385 			/* extend the last partition to maximuim */
386 			gpt_e[i].ending_lba = gpt_h->last_usable_lba;
387 		else
388 			gpt_e[i].ending_lba = cpu_to_le64(offset - 1);
389 
390 		/* partition type GUID */
391 		memcpy(gpt_e[i].partition_type_guid.b,
392 			&PARTITION_BASIC_DATA_GUID, 16);
393 
394 #ifdef CONFIG_PARTITION_UUIDS
395 		str_uuid = partitions[i].uuid;
396 		if (string_uuid(str_uuid, gpt_e[i].unique_partition_guid.b)) {
397 			printf("Partition no. %d: invalid guid: %s\n",
398 				i, str_uuid);
399 			return -1;
400 		}
401 #endif
402 
403 		/* partition attributes */
404 		memset(&gpt_e[i].attributes, 0,
405 		       sizeof(gpt_entry_attributes));
406 
407 		/* partition name */
408 		efiname_len = sizeof(gpt_e[i].partition_name)
409 			/ sizeof(efi_char16_t);
410 		dosname_len = sizeof(partitions[i].name);
411 
412 		memset(gpt_e[i].partition_name, 0,
413 		       sizeof(gpt_e[i].partition_name));
414 
415 		for (k = 0; k < min(dosname_len, efiname_len); k++)
416 			gpt_e[i].partition_name[k] =
417 				(efi_char16_t)(partitions[i].name[k]);
418 
419 		debug("%s: name: %s offset[%d]: 0x%x size[%d]: 0x" LBAF "\n",
420 		      __func__, partitions[i].name, i,
421 		      offset, i, partitions[i].size);
422 	}
423 
424 	return 0;
425 }
426 
427 int gpt_fill_header(block_dev_desc_t *dev_desc, gpt_header *gpt_h,
428 		char *str_guid, int parts_count)
429 {
430 	gpt_h->signature = cpu_to_le64(GPT_HEADER_SIGNATURE);
431 	gpt_h->revision = cpu_to_le32(GPT_HEADER_REVISION_V1);
432 	gpt_h->header_size = cpu_to_le32(sizeof(gpt_header));
433 	gpt_h->my_lba = cpu_to_le64(1);
434 	gpt_h->alternate_lba = cpu_to_le64(dev_desc->lba - 1);
435 	gpt_h->first_usable_lba = cpu_to_le64(34);
436 	gpt_h->last_usable_lba = cpu_to_le64(dev_desc->lba - 34);
437 	gpt_h->partition_entry_lba = cpu_to_le64(2);
438 	gpt_h->num_partition_entries = cpu_to_le32(GPT_ENTRY_NUMBERS);
439 	gpt_h->sizeof_partition_entry = cpu_to_le32(sizeof(gpt_entry));
440 	gpt_h->header_crc32 = 0;
441 	gpt_h->partition_entry_array_crc32 = 0;
442 
443 	if (string_uuid(str_guid, gpt_h->disk_guid.b))
444 		return -1;
445 
446 	return 0;
447 }
448 
449 int gpt_restore(block_dev_desc_t *dev_desc, char *str_disk_guid,
450 		disk_partition_t *partitions, int parts_count)
451 {
452 	int ret;
453 
454 	gpt_header *gpt_h = calloc(1, PAD_TO_BLOCKSIZE(sizeof(gpt_header),
455 						       dev_desc));
456 	gpt_entry *gpt_e;
457 
458 	if (gpt_h == NULL) {
459 		printf("%s: calloc failed!\n", __func__);
460 		return -1;
461 	}
462 
463 	gpt_e = calloc(1, PAD_TO_BLOCKSIZE(GPT_ENTRY_NUMBERS
464 					       * sizeof(gpt_entry),
465 					       dev_desc));
466 	if (gpt_e == NULL) {
467 		printf("%s: calloc failed!\n", __func__);
468 		free(gpt_h);
469 		return -1;
470 	}
471 
472 	/* Generate Primary GPT header (LBA1) */
473 	ret = gpt_fill_header(dev_desc, gpt_h, str_disk_guid, parts_count);
474 	if (ret)
475 		goto err;
476 
477 	/* Generate partition entries */
478 	ret = gpt_fill_pte(gpt_h, gpt_e, partitions, parts_count);
479 	if (ret)
480 		goto err;
481 
482 	/* Write GPT partition table */
483 	ret = write_gpt_table(dev_desc, gpt_h, gpt_e);
484 
485 err:
486 	free(gpt_e);
487 	free(gpt_h);
488 	return ret;
489 }
490 #endif
491 
492 /*
493  * Private functions
494  */
495 /*
496  * pmbr_part_valid(): Check for EFI partition signature
497  *
498  * Returns: 1 if EFI GPT partition type is found.
499  */
500 static int pmbr_part_valid(struct partition *part)
501 {
502 	if (part->sys_ind == EFI_PMBR_OSTYPE_EFI_GPT &&
503 		get_unaligned_le32(&part->start_sect) == 1UL) {
504 		return 1;
505 	}
506 
507 	return 0;
508 }
509 
510 /*
511  * is_pmbr_valid(): test Protective MBR for validity
512  *
513  * Returns: 1 if PMBR is valid, 0 otherwise.
514  * Validity depends on two things:
515  *  1) MSDOS signature is in the last two bytes of the MBR
516  *  2) One partition of type 0xEE is found, checked by pmbr_part_valid()
517  */
518 static int is_pmbr_valid(legacy_mbr * mbr)
519 {
520 	int i = 0;
521 
522 	if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
523 		return 0;
524 
525 	for (i = 0; i < 4; i++) {
526 		if (pmbr_part_valid(&mbr->partition_record[i])) {
527 			return 1;
528 		}
529 	}
530 	return 0;
531 }
532 
533 /**
534  * is_gpt_valid() - tests one GPT header and PTEs for validity
535  *
536  * lba is the logical block address of the GPT header to test
537  * gpt is a GPT header ptr, filled on return.
538  * ptes is a PTEs ptr, filled on return.
539  *
540  * Description: returns 1 if valid,  0 on error.
541  * If valid, returns pointers to PTEs.
542  */
543 static int is_gpt_valid(block_dev_desc_t * dev_desc, unsigned long long lba,
544 			gpt_header * pgpt_head, gpt_entry ** pgpt_pte)
545 {
546 	u32 crc32_backup = 0;
547 	u32 calc_crc32;
548 	unsigned long long lastlba;
549 
550 	if (!dev_desc || !pgpt_head) {
551 		printf("%s: Invalid Argument(s)\n", __func__);
552 		return 0;
553 	}
554 
555 	/* Read GPT Header from device */
556 	if (dev_desc->block_read(dev_desc->dev, lba, 1, pgpt_head) != 1) {
557 		printf("*** ERROR: Can't read GPT header ***\n");
558 		return 0;
559 	}
560 
561 	/* Check the GPT header signature */
562 	if (le64_to_cpu(pgpt_head->signature) != GPT_HEADER_SIGNATURE) {
563 		printf("GUID Partition Table Header signature is wrong:"
564 			"0x%llX != 0x%llX\n",
565 			le64_to_cpu(pgpt_head->signature),
566 			GPT_HEADER_SIGNATURE);
567 		return 0;
568 	}
569 
570 	/* Check the GUID Partition Table CRC */
571 	memcpy(&crc32_backup, &pgpt_head->header_crc32, sizeof(crc32_backup));
572 	memset(&pgpt_head->header_crc32, 0, sizeof(pgpt_head->header_crc32));
573 
574 	calc_crc32 = efi_crc32((const unsigned char *)pgpt_head,
575 		le32_to_cpu(pgpt_head->header_size));
576 
577 	memcpy(&pgpt_head->header_crc32, &crc32_backup, sizeof(crc32_backup));
578 
579 	if (calc_crc32 != le32_to_cpu(crc32_backup)) {
580 		printf("GUID Partition Table Header CRC is wrong:"
581 			"0x%x != 0x%x\n",
582 		       le32_to_cpu(crc32_backup), calc_crc32);
583 		return 0;
584 	}
585 
586 	/* Check that the my_lba entry points to the LBA that contains the GPT */
587 	if (le64_to_cpu(pgpt_head->my_lba) != lba) {
588 		printf("GPT: my_lba incorrect: %llX != %llX\n",
589 			le64_to_cpu(pgpt_head->my_lba),
590 			lba);
591 		return 0;
592 	}
593 
594 	/* Check the first_usable_lba and last_usable_lba are within the disk. */
595 	lastlba = (unsigned long long)dev_desc->lba;
596 	if (le64_to_cpu(pgpt_head->first_usable_lba) > lastlba) {
597 		printf("GPT: first_usable_lba incorrect: %llX > %llX\n",
598 			le64_to_cpu(pgpt_head->first_usable_lba), lastlba);
599 		return 0;
600 	}
601 	if (le64_to_cpu(pgpt_head->last_usable_lba) > lastlba) {
602 		printf("GPT: last_usable_lba incorrect: %llX > %llX\n",
603 			(u64) le64_to_cpu(pgpt_head->last_usable_lba), lastlba);
604 		return 0;
605 	}
606 
607 	debug("GPT: first_usable_lba: %llX last_usable_lba %llX last lba %llX\n",
608 		le64_to_cpu(pgpt_head->first_usable_lba),
609 		le64_to_cpu(pgpt_head->last_usable_lba), lastlba);
610 
611 	/* Read and allocate Partition Table Entries */
612 	*pgpt_pte = alloc_read_gpt_entries(dev_desc, pgpt_head);
613 	if (*pgpt_pte == NULL) {
614 		printf("GPT: Failed to allocate memory for PTE\n");
615 		return 0;
616 	}
617 
618 	/* Check the GUID Partition Table Entry Array CRC */
619 	calc_crc32 = efi_crc32((const unsigned char *)*pgpt_pte,
620 		le32_to_cpu(pgpt_head->num_partition_entries) *
621 		le32_to_cpu(pgpt_head->sizeof_partition_entry));
622 
623 	if (calc_crc32 != le32_to_cpu(pgpt_head->partition_entry_array_crc32)) {
624 		printf("GUID Partition Table Entry Array CRC is wrong:"
625 			"0x%x != 0x%x\n",
626 			le32_to_cpu(pgpt_head->partition_entry_array_crc32),
627 			calc_crc32);
628 
629 		free(*pgpt_pte);
630 		return 0;
631 	}
632 
633 	/* We're done, all's well */
634 	return 1;
635 }
636 
637 /**
638  * alloc_read_gpt_entries(): reads partition entries from disk
639  * @dev_desc
640  * @gpt - GPT header
641  *
642  * Description: Returns ptes on success,  NULL on error.
643  * Allocates space for PTEs based on information found in @gpt.
644  * Notes: remember to free pte when you're done!
645  */
646 static gpt_entry *alloc_read_gpt_entries(block_dev_desc_t * dev_desc,
647 					 gpt_header * pgpt_head)
648 {
649 	size_t count = 0, blk_cnt;
650 	gpt_entry *pte = NULL;
651 
652 	if (!dev_desc || !pgpt_head) {
653 		printf("%s: Invalid Argument(s)\n", __func__);
654 		return NULL;
655 	}
656 
657 	count = le32_to_cpu(pgpt_head->num_partition_entries) *
658 		le32_to_cpu(pgpt_head->sizeof_partition_entry);
659 
660 	debug("%s: count = %u * %u = %zu\n", __func__,
661 	      (u32) le32_to_cpu(pgpt_head->num_partition_entries),
662 	      (u32) le32_to_cpu(pgpt_head->sizeof_partition_entry), count);
663 
664 	/* Allocate memory for PTE, remember to FREE */
665 	if (count != 0) {
666 		pte = memalign(ARCH_DMA_MINALIGN,
667 			       PAD_TO_BLOCKSIZE(count, dev_desc));
668 	}
669 
670 	if (count == 0 || pte == NULL) {
671 		printf("%s: ERROR: Can't allocate 0x%zX "
672 		       "bytes for GPT Entries\n",
673 			__func__, count);
674 		return NULL;
675 	}
676 
677 	/* Read GPT Entries from device */
678 	blk_cnt = BLOCK_CNT(count, dev_desc);
679 	if (dev_desc->block_read (dev_desc->dev,
680 		le64_to_cpu(pgpt_head->partition_entry_lba),
681 		(lbaint_t) (blk_cnt), pte)
682 		!= blk_cnt) {
683 
684 		printf("*** ERROR: Can't read GPT Entries ***\n");
685 		free(pte);
686 		return NULL;
687 	}
688 	return pte;
689 }
690 
691 /**
692  * is_pte_valid(): validates a single Partition Table Entry
693  * @gpt_entry - Pointer to a single Partition Table Entry
694  *
695  * Description: returns 1 if valid,  0 on error.
696  */
697 static int is_pte_valid(gpt_entry * pte)
698 {
699 	efi_guid_t unused_guid;
700 
701 	if (!pte) {
702 		printf("%s: Invalid Argument(s)\n", __func__);
703 		return 0;
704 	}
705 
706 	/* Only one validation for now:
707 	 * The GUID Partition Type != Unused Entry (ALL-ZERO)
708 	 */
709 	memset(unused_guid.b, 0, sizeof(unused_guid.b));
710 
711 	if (memcmp(pte->partition_type_guid.b, unused_guid.b,
712 		sizeof(unused_guid.b)) == 0) {
713 
714 		debug("%s: Found an unused PTE GUID at 0x%08X\n", __func__,
715 		      (unsigned int)(uintptr_t)pte);
716 
717 		return 0;
718 	} else {
719 		return 1;
720 	}
721 }
722 #endif
723