xref: /openbmc/u-boot/disk/part_efi.c (revision 425faf74)
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 		printf("%s: *** ERROR: Invalid partition number %d ***\n",
168 			__func__, part);
169 		return -1;
170 	}
171 
172 	/* The ulong casting limits the maximum disk size to 2 TB */
173 	info->start = (u64)le64_to_cpu(gpt_pte[part - 1].starting_lba);
174 	/* The ending LBA is inclusive, to calculate size, add 1 to it */
175 	info->size = ((u64)le64_to_cpu(gpt_pte[part - 1].ending_lba) + 1)
176 		     - info->start;
177 	info->blksz = dev_desc->blksz;
178 
179 	sprintf((char *)info->name, "%s",
180 			print_efiname(&gpt_pte[part - 1]));
181 	sprintf((char *)info->type, "U-Boot");
182 	info->bootable = is_bootable(&gpt_pte[part - 1]);
183 #ifdef CONFIG_PARTITION_UUIDS
184 	uuid_string(gpt_pte[part - 1].unique_partition_guid.b, info->uuid);
185 #endif
186 
187 	debug("%s: start 0x" LBAF ", size 0x" LBAF ", name %s", __func__,
188 	      info->start, info->size, info->name);
189 
190 	/* Remember to free pte */
191 	free(gpt_pte);
192 	return 0;
193 }
194 
195 int test_part_efi(block_dev_desc_t * dev_desc)
196 {
197 	ALLOC_CACHE_ALIGN_BUFFER_PAD(legacy_mbr, legacymbr, 1, dev_desc->blksz);
198 
199 	/* Read legacy MBR from block 0 and validate it */
200 	if ((dev_desc->block_read(dev_desc->dev, 0, 1, (ulong *)legacymbr) != 1)
201 		|| (is_pmbr_valid(legacymbr) != 1)) {
202 		return -1;
203 	}
204 	return 0;
205 }
206 
207 /**
208  * set_protective_mbr(): Set the EFI protective MBR
209  * @param dev_desc - block device descriptor
210  *
211  * @return - zero on success, otherwise error
212  */
213 static int set_protective_mbr(block_dev_desc_t *dev_desc)
214 {
215 	legacy_mbr *p_mbr;
216 
217 	/* Setup the Protective MBR */
218 	p_mbr = calloc(1, sizeof(p_mbr));
219 	if (p_mbr == NULL) {
220 		printf("%s: calloc failed!\n", __func__);
221 		return -1;
222 	}
223 	/* Append signature */
224 	p_mbr->signature = MSDOS_MBR_SIGNATURE;
225 	p_mbr->partition_record[0].sys_ind = EFI_PMBR_OSTYPE_EFI_GPT;
226 	p_mbr->partition_record[0].start_sect = 1;
227 	p_mbr->partition_record[0].nr_sects = (u32) dev_desc->lba;
228 
229 	/* Write MBR sector to the MMC device */
230 	if (dev_desc->block_write(dev_desc->dev, 0, 1, p_mbr) != 1) {
231 		printf("** Can't write to device %d **\n",
232 			dev_desc->dev);
233 		free(p_mbr);
234 		return -1;
235 	}
236 
237 	free(p_mbr);
238 	return 0;
239 }
240 
241 /**
242  * string_uuid(); Convert UUID stored as string to bytes
243  *
244  * @param uuid - UUID represented as string
245  * @param dst - GUID buffer
246  *
247  * @return return 0 on successful conversion
248  */
249 static int string_uuid(char *uuid, u8 *dst)
250 {
251 	efi_guid_t guid;
252 	u16 b, c, d;
253 	u64 e;
254 	u32 a;
255 	u8 *p;
256 	u8 i;
257 
258 	const u8 uuid_str_len = 36;
259 
260 	/* The UUID is written in text: */
261 	/* 1        9    14   19   24 */
262 	/* xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx */
263 
264 	debug("%s: uuid: %s\n", __func__, uuid);
265 
266 	if (strlen(uuid) != uuid_str_len)
267 		return -1;
268 
269 	for (i = 0; i < uuid_str_len; i++) {
270 		if ((i == 8) || (i == 13) || (i == 18) || (i == 23)) {
271 			if (uuid[i] != '-')
272 				return -1;
273 		} else {
274 			if (!isxdigit(uuid[i]))
275 				return -1;
276 		}
277 	}
278 
279 	a = (u32)simple_strtoul(uuid, NULL, 16);
280 	b = (u16)simple_strtoul(uuid + 9, NULL, 16);
281 	c = (u16)simple_strtoul(uuid + 14, NULL, 16);
282 	d = (u16)simple_strtoul(uuid + 19, NULL, 16);
283 	e = (u64)simple_strtoull(uuid + 24, NULL, 16);
284 
285 	p = (u8 *) &e;
286 	guid = EFI_GUID(a, b, c, d >> 8, d & 0xFF,
287 			*(p + 5), *(p + 4), *(p + 3),
288 			*(p + 2), *(p + 1) , *p);
289 
290 	memcpy(dst, guid.b, sizeof(efi_guid_t));
291 
292 	return 0;
293 }
294 
295 int write_gpt_table(block_dev_desc_t *dev_desc,
296 		gpt_header *gpt_h, gpt_entry *gpt_e)
297 {
298 	const int pte_blk_cnt = BLOCK_CNT((gpt_h->num_partition_entries
299 					   * sizeof(gpt_entry)), dev_desc);
300 	u32 calc_crc32;
301 	u64 val;
302 
303 	debug("max lba: %x\n", (u32) dev_desc->lba);
304 	/* Setup the Protective MBR */
305 	if (set_protective_mbr(dev_desc) < 0)
306 		goto err;
307 
308 	/* Generate CRC for the Primary GPT Header */
309 	calc_crc32 = efi_crc32((const unsigned char *)gpt_e,
310 			      le32_to_cpu(gpt_h->num_partition_entries) *
311 			      le32_to_cpu(gpt_h->sizeof_partition_entry));
312 	gpt_h->partition_entry_array_crc32 = cpu_to_le32(calc_crc32);
313 
314 	calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
315 			      le32_to_cpu(gpt_h->header_size));
316 	gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
317 
318 	/* Write the First GPT to the block right after the Legacy MBR */
319 	if (dev_desc->block_write(dev_desc->dev, 1, 1, gpt_h) != 1)
320 		goto err;
321 
322 	if (dev_desc->block_write(dev_desc->dev, 2, pte_blk_cnt, gpt_e)
323 	    != pte_blk_cnt)
324 		goto err;
325 
326 	/* recalculate the values for the Second GPT Header */
327 	val = le64_to_cpu(gpt_h->my_lba);
328 	gpt_h->my_lba = gpt_h->alternate_lba;
329 	gpt_h->alternate_lba = cpu_to_le64(val);
330 	gpt_h->header_crc32 = 0;
331 
332 	calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
333 			      le32_to_cpu(gpt_h->header_size));
334 	gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
335 
336 	if (dev_desc->block_write(dev_desc->dev,
337 				  le32_to_cpu(gpt_h->last_usable_lba + 1),
338 				  pte_blk_cnt, gpt_e) != pte_blk_cnt)
339 		goto err;
340 
341 	if (dev_desc->block_write(dev_desc->dev,
342 				  le32_to_cpu(gpt_h->my_lba), 1, gpt_h) != 1)
343 		goto err;
344 
345 	debug("GPT successfully written to block device!\n");
346 	return 0;
347 
348  err:
349 	printf("** Can't write to device %d **\n", dev_desc->dev);
350 	return -1;
351 }
352 
353 int gpt_fill_pte(gpt_header *gpt_h, gpt_entry *gpt_e,
354 		disk_partition_t *partitions, int parts)
355 {
356 	u32 offset = (u32)le32_to_cpu(gpt_h->first_usable_lba);
357 	ulong start;
358 	int i, k;
359 	size_t efiname_len, dosname_len;
360 #ifdef CONFIG_PARTITION_UUIDS
361 	char *str_uuid;
362 #endif
363 
364 	for (i = 0; i < parts; i++) {
365 		/* partition starting lba */
366 		start = partitions[i].start;
367 		if (start && (start < offset)) {
368 			printf("Partition overlap\n");
369 			return -1;
370 		}
371 		if (start) {
372 			gpt_e[i].starting_lba = cpu_to_le64(start);
373 			offset = start + partitions[i].size;
374 		} else {
375 			gpt_e[i].starting_lba = cpu_to_le64(offset);
376 			offset += partitions[i].size;
377 		}
378 		if (offset >= gpt_h->last_usable_lba) {
379 			printf("Partitions layout exceds disk size\n");
380 			return -1;
381 		}
382 		/* partition ending lba */
383 		if ((i == parts - 1) && (partitions[i].size == 0))
384 			/* extend the last partition to maximuim */
385 			gpt_e[i].ending_lba = gpt_h->last_usable_lba;
386 		else
387 			gpt_e[i].ending_lba = cpu_to_le64(offset - 1);
388 
389 		/* partition type GUID */
390 		memcpy(gpt_e[i].partition_type_guid.b,
391 			&PARTITION_BASIC_DATA_GUID, 16);
392 
393 #ifdef CONFIG_PARTITION_UUIDS
394 		str_uuid = partitions[i].uuid;
395 		if (string_uuid(str_uuid, gpt_e[i].unique_partition_guid.b)) {
396 			printf("Partition no. %d: invalid guid: %s\n",
397 				i, str_uuid);
398 			return -1;
399 		}
400 #endif
401 
402 		/* partition attributes */
403 		memset(&gpt_e[i].attributes, 0,
404 		       sizeof(gpt_entry_attributes));
405 
406 		/* partition name */
407 		efiname_len = sizeof(gpt_e[i].partition_name)
408 			/ sizeof(efi_char16_t);
409 		dosname_len = sizeof(partitions[i].name);
410 
411 		memset(gpt_e[i].partition_name, 0,
412 		       sizeof(gpt_e[i].partition_name));
413 
414 		for (k = 0; k < min(dosname_len, efiname_len); k++)
415 			gpt_e[i].partition_name[k] =
416 				(efi_char16_t)(partitions[i].name[k]);
417 
418 		debug("%s: name: %s offset[%d]: 0x%x size[%d]: 0x" LBAF "\n",
419 		      __func__, partitions[i].name, i,
420 		      offset, i, partitions[i].size);
421 	}
422 
423 	return 0;
424 }
425 
426 int gpt_fill_header(block_dev_desc_t *dev_desc, gpt_header *gpt_h,
427 		char *str_guid, int parts_count)
428 {
429 	gpt_h->signature = cpu_to_le64(GPT_HEADER_SIGNATURE);
430 	gpt_h->revision = cpu_to_le32(GPT_HEADER_REVISION_V1);
431 	gpt_h->header_size = cpu_to_le32(sizeof(gpt_header));
432 	gpt_h->my_lba = cpu_to_le64(1);
433 	gpt_h->alternate_lba = cpu_to_le64(dev_desc->lba - 1);
434 	gpt_h->first_usable_lba = cpu_to_le64(34);
435 	gpt_h->last_usable_lba = cpu_to_le64(dev_desc->lba - 34);
436 	gpt_h->partition_entry_lba = cpu_to_le64(2);
437 	gpt_h->num_partition_entries = cpu_to_le32(GPT_ENTRY_NUMBERS);
438 	gpt_h->sizeof_partition_entry = cpu_to_le32(sizeof(gpt_entry));
439 	gpt_h->header_crc32 = 0;
440 	gpt_h->partition_entry_array_crc32 = 0;
441 
442 	if (string_uuid(str_guid, gpt_h->disk_guid.b))
443 		return -1;
444 
445 	return 0;
446 }
447 
448 int gpt_restore(block_dev_desc_t *dev_desc, char *str_disk_guid,
449 		disk_partition_t *partitions, int parts_count)
450 {
451 	int ret;
452 
453 	gpt_header *gpt_h = calloc(1, PAD_TO_BLOCKSIZE(sizeof(gpt_header),
454 						       dev_desc));
455 	gpt_entry *gpt_e;
456 
457 	if (gpt_h == NULL) {
458 		printf("%s: calloc failed!\n", __func__);
459 		return -1;
460 	}
461 
462 	gpt_e = calloc(1, PAD_TO_BLOCKSIZE(GPT_ENTRY_NUMBERS
463 					       * sizeof(gpt_entry),
464 					       dev_desc));
465 	if (gpt_e == NULL) {
466 		printf("%s: calloc failed!\n", __func__);
467 		free(gpt_h);
468 		return -1;
469 	}
470 
471 	/* Generate Primary GPT header (LBA1) */
472 	ret = gpt_fill_header(dev_desc, gpt_h, str_disk_guid, parts_count);
473 	if (ret)
474 		goto err;
475 
476 	/* Generate partition entries */
477 	ret = gpt_fill_pte(gpt_h, gpt_e, partitions, parts_count);
478 	if (ret)
479 		goto err;
480 
481 	/* Write GPT partition table */
482 	ret = write_gpt_table(dev_desc, gpt_h, gpt_e);
483 
484 err:
485 	free(gpt_e);
486 	free(gpt_h);
487 	return ret;
488 }
489 #endif
490 
491 /*
492  * Private functions
493  */
494 /*
495  * pmbr_part_valid(): Check for EFI partition signature
496  *
497  * Returns: 1 if EFI GPT partition type is found.
498  */
499 static int pmbr_part_valid(struct partition *part)
500 {
501 	if (part->sys_ind == EFI_PMBR_OSTYPE_EFI_GPT &&
502 		get_unaligned_le32(&part->start_sect) == 1UL) {
503 		return 1;
504 	}
505 
506 	return 0;
507 }
508 
509 /*
510  * is_pmbr_valid(): test Protective MBR for validity
511  *
512  * Returns: 1 if PMBR is valid, 0 otherwise.
513  * Validity depends on two things:
514  *  1) MSDOS signature is in the last two bytes of the MBR
515  *  2) One partition of type 0xEE is found, checked by pmbr_part_valid()
516  */
517 static int is_pmbr_valid(legacy_mbr * mbr)
518 {
519 	int i = 0;
520 
521 	if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
522 		return 0;
523 
524 	for (i = 0; i < 4; i++) {
525 		if (pmbr_part_valid(&mbr->partition_record[i])) {
526 			return 1;
527 		}
528 	}
529 	return 0;
530 }
531 
532 /**
533  * is_gpt_valid() - tests one GPT header and PTEs for validity
534  *
535  * lba is the logical block address of the GPT header to test
536  * gpt is a GPT header ptr, filled on return.
537  * ptes is a PTEs ptr, filled on return.
538  *
539  * Description: returns 1 if valid,  0 on error.
540  * If valid, returns pointers to PTEs.
541  */
542 static int is_gpt_valid(block_dev_desc_t * dev_desc, unsigned long long lba,
543 			gpt_header * pgpt_head, gpt_entry ** pgpt_pte)
544 {
545 	u32 crc32_backup = 0;
546 	u32 calc_crc32;
547 	unsigned long long lastlba;
548 
549 	if (!dev_desc || !pgpt_head) {
550 		printf("%s: Invalid Argument(s)\n", __func__);
551 		return 0;
552 	}
553 
554 	/* Read GPT Header from device */
555 	if (dev_desc->block_read(dev_desc->dev, lba, 1, pgpt_head) != 1) {
556 		printf("*** ERROR: Can't read GPT header ***\n");
557 		return 0;
558 	}
559 
560 	/* Check the GPT header signature */
561 	if (le64_to_cpu(pgpt_head->signature) != GPT_HEADER_SIGNATURE) {
562 		printf("GUID Partition Table Header signature is wrong:"
563 			"0x%llX != 0x%llX\n",
564 			le64_to_cpu(pgpt_head->signature),
565 			GPT_HEADER_SIGNATURE);
566 		return 0;
567 	}
568 
569 	/* Check the GUID Partition Table CRC */
570 	memcpy(&crc32_backup, &pgpt_head->header_crc32, sizeof(crc32_backup));
571 	memset(&pgpt_head->header_crc32, 0, sizeof(pgpt_head->header_crc32));
572 
573 	calc_crc32 = efi_crc32((const unsigned char *)pgpt_head,
574 		le32_to_cpu(pgpt_head->header_size));
575 
576 	memcpy(&pgpt_head->header_crc32, &crc32_backup, sizeof(crc32_backup));
577 
578 	if (calc_crc32 != le32_to_cpu(crc32_backup)) {
579 		printf("GUID Partition Table Header CRC is wrong:"
580 			"0x%x != 0x%x\n",
581 		       le32_to_cpu(crc32_backup), calc_crc32);
582 		return 0;
583 	}
584 
585 	/* Check that the my_lba entry points to the LBA that contains the GPT */
586 	if (le64_to_cpu(pgpt_head->my_lba) != lba) {
587 		printf("GPT: my_lba incorrect: %llX != %llX\n",
588 			le64_to_cpu(pgpt_head->my_lba),
589 			lba);
590 		return 0;
591 	}
592 
593 	/* Check the first_usable_lba and last_usable_lba are within the disk. */
594 	lastlba = (unsigned long long)dev_desc->lba;
595 	if (le64_to_cpu(pgpt_head->first_usable_lba) > lastlba) {
596 		printf("GPT: first_usable_lba incorrect: %llX > %llX\n",
597 			le64_to_cpu(pgpt_head->first_usable_lba), lastlba);
598 		return 0;
599 	}
600 	if (le64_to_cpu(pgpt_head->last_usable_lba) > lastlba) {
601 		printf("GPT: last_usable_lba incorrect: %llX > %llX\n",
602 			(u64) le64_to_cpu(pgpt_head->last_usable_lba), lastlba);
603 		return 0;
604 	}
605 
606 	debug("GPT: first_usable_lba: %llX last_usable_lba %llX last lba %llX\n",
607 		le64_to_cpu(pgpt_head->first_usable_lba),
608 		le64_to_cpu(pgpt_head->last_usable_lba), lastlba);
609 
610 	/* Read and allocate Partition Table Entries */
611 	*pgpt_pte = alloc_read_gpt_entries(dev_desc, pgpt_head);
612 	if (*pgpt_pte == NULL) {
613 		printf("GPT: Failed to allocate memory for PTE\n");
614 		return 0;
615 	}
616 
617 	/* Check the GUID Partition Table Entry Array CRC */
618 	calc_crc32 = efi_crc32((const unsigned char *)*pgpt_pte,
619 		le32_to_cpu(pgpt_head->num_partition_entries) *
620 		le32_to_cpu(pgpt_head->sizeof_partition_entry));
621 
622 	if (calc_crc32 != le32_to_cpu(pgpt_head->partition_entry_array_crc32)) {
623 		printf("GUID Partition Table Entry Array CRC is wrong:"
624 			"0x%x != 0x%x\n",
625 			le32_to_cpu(pgpt_head->partition_entry_array_crc32),
626 			calc_crc32);
627 
628 		free(*pgpt_pte);
629 		return 0;
630 	}
631 
632 	/* We're done, all's well */
633 	return 1;
634 }
635 
636 /**
637  * alloc_read_gpt_entries(): reads partition entries from disk
638  * @dev_desc
639  * @gpt - GPT header
640  *
641  * Description: Returns ptes on success,  NULL on error.
642  * Allocates space for PTEs based on information found in @gpt.
643  * Notes: remember to free pte when you're done!
644  */
645 static gpt_entry *alloc_read_gpt_entries(block_dev_desc_t * dev_desc,
646 					 gpt_header * pgpt_head)
647 {
648 	size_t count = 0, blk_cnt;
649 	gpt_entry *pte = NULL;
650 
651 	if (!dev_desc || !pgpt_head) {
652 		printf("%s: Invalid Argument(s)\n", __func__);
653 		return NULL;
654 	}
655 
656 	count = le32_to_cpu(pgpt_head->num_partition_entries) *
657 		le32_to_cpu(pgpt_head->sizeof_partition_entry);
658 
659 	debug("%s: count = %u * %u = %zu\n", __func__,
660 	      (u32) le32_to_cpu(pgpt_head->num_partition_entries),
661 	      (u32) le32_to_cpu(pgpt_head->sizeof_partition_entry), count);
662 
663 	/* Allocate memory for PTE, remember to FREE */
664 	if (count != 0) {
665 		pte = memalign(ARCH_DMA_MINALIGN,
666 			       PAD_TO_BLOCKSIZE(count, dev_desc));
667 	}
668 
669 	if (count == 0 || pte == NULL) {
670 		printf("%s: ERROR: Can't allocate 0x%zX "
671 		       "bytes for GPT Entries\n",
672 			__func__, count);
673 		return NULL;
674 	}
675 
676 	/* Read GPT Entries from device */
677 	blk_cnt = BLOCK_CNT(count, dev_desc);
678 	if (dev_desc->block_read (dev_desc->dev,
679 		le64_to_cpu(pgpt_head->partition_entry_lba),
680 		(lbaint_t) (blk_cnt), pte)
681 		!= blk_cnt) {
682 
683 		printf("*** ERROR: Can't read GPT Entries ***\n");
684 		free(pte);
685 		return NULL;
686 	}
687 	return pte;
688 }
689 
690 /**
691  * is_pte_valid(): validates a single Partition Table Entry
692  * @gpt_entry - Pointer to a single Partition Table Entry
693  *
694  * Description: returns 1 if valid,  0 on error.
695  */
696 static int is_pte_valid(gpt_entry * pte)
697 {
698 	efi_guid_t unused_guid;
699 
700 	if (!pte) {
701 		printf("%s: Invalid Argument(s)\n", __func__);
702 		return 0;
703 	}
704 
705 	/* Only one validation for now:
706 	 * The GUID Partition Type != Unused Entry (ALL-ZERO)
707 	 */
708 	memset(unused_guid.b, 0, sizeof(unused_guid.b));
709 
710 	if (memcmp(pte->partition_type_guid.b, unused_guid.b,
711 		sizeof(unused_guid.b)) == 0) {
712 
713 		debug("%s: Found an unused PTE GUID at 0x%08X\n", __func__,
714 		      (unsigned int)(uintptr_t)pte);
715 
716 		return 0;
717 	} else {
718 		return 1;
719 	}
720 }
721 #endif
722