xref: /openbmc/u-boot/disk/part_efi.c (revision de757a7a)
1 /*
2  * Copyright (C) 2008 RuggedCom, Inc.
3  * Richard Retanubun <RichardRetanubun@RuggedCom.com>
4  *
5  * See file CREDITS for list of people who contributed to this
6  * project.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of
11  * the License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21  * MA 02111-1307 USA
22  */
23 
24 /*
25  * Problems with CONFIG_SYS_64BIT_LBA:
26  *
27  * struct disk_partition.start in include/part.h is sized as ulong.
28  * When CONFIG_SYS_64BIT_LBA is activated, lbaint_t changes from ulong to uint64_t.
29  * For now, it is cast back to ulong at assignment.
30  *
31  * This limits the maximum size of addressable storage to < 2 Terra Bytes
32  */
33 #include <common.h>
34 #include <command.h>
35 #include <ide.h>
36 #include <malloc.h>
37 #include <part_efi.h>
38 #include <linux/ctype.h>
39 
40 DECLARE_GLOBAL_DATA_PTR;
41 
42 #if defined(CONFIG_CMD_IDE) || \
43     defined(CONFIG_CMD_SATA) || \
44     defined(CONFIG_CMD_SCSI) || \
45     defined(CONFIG_CMD_USB) || \
46     defined(CONFIG_MMC) || \
47     defined(CONFIG_SYSTEMACE)
48 
49 /**
50  * efi_crc32() - EFI version of crc32 function
51  * @buf: buffer to calculate crc32 of
52  * @len - length of buf
53  *
54  * Description: Returns EFI-style CRC32 value for @buf
55  */
56 static inline u32 efi_crc32(const void *buf, u32 len)
57 {
58 	return crc32(0, buf, len);
59 }
60 
61 /*
62  * Private function prototypes
63  */
64 
65 static int pmbr_part_valid(struct partition *part);
66 static int is_pmbr_valid(legacy_mbr * mbr);
67 static int is_gpt_valid(block_dev_desc_t * dev_desc, unsigned long long lba,
68 				gpt_header * pgpt_head, gpt_entry ** pgpt_pte);
69 static gpt_entry *alloc_read_gpt_entries(block_dev_desc_t * dev_desc,
70 				gpt_header * pgpt_head);
71 static int is_pte_valid(gpt_entry * pte);
72 
73 static char *print_efiname(gpt_entry *pte)
74 {
75 	static char name[PARTNAME_SZ + 1];
76 	int i;
77 	for (i = 0; i < PARTNAME_SZ; i++) {
78 		u8 c;
79 		c = pte->partition_name[i] & 0xff;
80 		c = (c && !isprint(c)) ? '.' : c;
81 		name[i] = c;
82 	}
83 	name[PARTNAME_SZ] = 0;
84 	return name;
85 }
86 
87 static void uuid_string(unsigned char *uuid, char *str)
88 {
89 	static const u8 le[16] = {3, 2, 1, 0, 5, 4, 7, 6, 8, 9, 10, 11,
90 				  12, 13, 14, 15};
91 	int i;
92 
93 	for (i = 0; i < 16; i++) {
94 		sprintf(str, "%02x", uuid[le[i]]);
95 		str += 2;
96 		switch (i) {
97 		case 3:
98 		case 5:
99 		case 7:
100 		case 9:
101 			*str++ = '-';
102 			break;
103 		}
104 	}
105 }
106 
107 static efi_guid_t system_guid = PARTITION_SYSTEM_GUID;
108 
109 static inline int is_bootable(gpt_entry *p)
110 {
111 	return p->attributes.fields.legacy_bios_bootable ||
112 		!memcmp(&(p->partition_type_guid), &system_guid,
113 			sizeof(efi_guid_t));
114 }
115 
116 #ifdef CONFIG_EFI_PARTITION
117 /*
118  * Public Functions (include/part.h)
119  */
120 
121 void print_part_efi(block_dev_desc_t * dev_desc)
122 {
123 	ALLOC_CACHE_ALIGN_BUFFER(gpt_header, gpt_head, 1);
124 	gpt_entry *gpt_pte = NULL;
125 	int i = 0;
126 	char uuid[37];
127 
128 	if (!dev_desc) {
129 		printf("%s: Invalid Argument(s)\n", __func__);
130 		return;
131 	}
132 	/* This function validates AND fills in the GPT header and PTE */
133 	if (is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA,
134 			 gpt_head, &gpt_pte) != 1) {
135 		printf("%s: *** ERROR: Invalid GPT ***\n", __func__);
136 		return;
137 	}
138 
139 	debug("%s: gpt-entry at %p\n", __func__, gpt_pte);
140 
141 	printf("Part\tStart LBA\tEnd LBA\t\tName\n");
142 	printf("\tAttributes\n");
143 	printf("\tType UUID\n");
144 	printf("\tPartition UUID\n");
145 
146 	for (i = 0; i < le32_to_cpu(gpt_head->num_partition_entries); i++) {
147 		/* Stop at the first non valid PTE */
148 		if (!is_pte_valid(&gpt_pte[i]))
149 			break;
150 
151 		printf("%3d\t0x%08llx\t0x%08llx\t\"%s\"\n", (i + 1),
152 			le64_to_cpu(gpt_pte[i].starting_lba),
153 			le64_to_cpu(gpt_pte[i].ending_lba),
154 			print_efiname(&gpt_pte[i]));
155 		printf("\tattrs:\t0x%016llx\n", gpt_pte[i].attributes.raw);
156 		uuid_string(gpt_pte[i].partition_type_guid.b, uuid);
157 		printf("\ttype:\t%s\n", uuid);
158 		uuid_string(gpt_pte[i].unique_partition_guid.b, uuid);
159 		printf("\tuuid:\t%s\n", uuid);
160 	}
161 
162 	/* Remember to free pte */
163 	free(gpt_pte);
164 	return;
165 }
166 
167 int get_partition_info_efi(block_dev_desc_t * dev_desc, int part,
168 				disk_partition_t * info)
169 {
170 	ALLOC_CACHE_ALIGN_BUFFER(gpt_header, gpt_head, 1);
171 	gpt_entry *gpt_pte = NULL;
172 
173 	/* "part" argument must be at least 1 */
174 	if (!dev_desc || !info || part < 1) {
175 		printf("%s: Invalid Argument(s)\n", __func__);
176 		return -1;
177 	}
178 
179 	/* This function validates AND fills in the GPT header and PTE */
180 	if (is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA,
181 			gpt_head, &gpt_pte) != 1) {
182 		printf("%s: *** ERROR: Invalid GPT ***\n", __func__);
183 		return -1;
184 	}
185 
186 	if (part > le32_to_cpu(gpt_head->num_partition_entries) ||
187 	    !is_pte_valid(&gpt_pte[part - 1])) {
188 		printf("%s: *** ERROR: Invalid partition number %d ***\n",
189 			__func__, part);
190 		return -1;
191 	}
192 
193 	/* The ulong casting limits the maximum disk size to 2 TB */
194 	info->start = (u64)le64_to_cpu(gpt_pte[part - 1].starting_lba);
195 	/* The ending LBA is inclusive, to calculate size, add 1 to it */
196 	info->size = ((u64)le64_to_cpu(gpt_pte[part - 1].ending_lba) + 1)
197 		     - info->start;
198 	info->blksz = GPT_BLOCK_SIZE;
199 
200 	sprintf((char *)info->name, "%s",
201 			print_efiname(&gpt_pte[part - 1]));
202 	sprintf((char *)info->type, "U-Boot");
203 	info->bootable = is_bootable(&gpt_pte[part - 1]);
204 #ifdef CONFIG_PARTITION_UUIDS
205 	uuid_string(gpt_pte[part - 1].unique_partition_guid.b, info->uuid);
206 #endif
207 
208 	debug("%s: start 0x%lX, size 0x%lX, name %s", __func__,
209 		info->start, info->size, info->name);
210 
211 	/* Remember to free pte */
212 	free(gpt_pte);
213 	return 0;
214 }
215 
216 int test_part_efi(block_dev_desc_t * dev_desc)
217 {
218 	ALLOC_CACHE_ALIGN_BUFFER(legacy_mbr, legacymbr, 1);
219 
220 	/* Read legacy MBR from block 0 and validate it */
221 	if ((dev_desc->block_read(dev_desc->dev, 0, 1, (ulong *)legacymbr) != 1)
222 		|| (is_pmbr_valid(legacymbr) != 1)) {
223 		return -1;
224 	}
225 	return 0;
226 }
227 
228 /**
229  * set_protective_mbr(): Set the EFI protective MBR
230  * @param dev_desc - block device descriptor
231  *
232  * @return - zero on success, otherwise error
233  */
234 static int set_protective_mbr(block_dev_desc_t *dev_desc)
235 {
236 	legacy_mbr *p_mbr;
237 
238 	/* Setup the Protective MBR */
239 	p_mbr = calloc(1, sizeof(p_mbr));
240 	if (p_mbr == NULL) {
241 		printf("%s: calloc failed!\n", __func__);
242 		return -1;
243 	}
244 	/* Append signature */
245 	p_mbr->signature = MSDOS_MBR_SIGNATURE;
246 	p_mbr->partition_record[0].sys_ind = EFI_PMBR_OSTYPE_EFI_GPT;
247 	p_mbr->partition_record[0].start_sect = 1;
248 	p_mbr->partition_record[0].nr_sects = (u32) dev_desc->lba;
249 
250 	/* Write MBR sector to the MMC device */
251 	if (dev_desc->block_write(dev_desc->dev, 0, 1, p_mbr) != 1) {
252 		printf("** Can't write to device %d **\n",
253 			dev_desc->dev);
254 		free(p_mbr);
255 		return -1;
256 	}
257 
258 	free(p_mbr);
259 	return 0;
260 }
261 
262 /**
263  * string_uuid(); Convert UUID stored as string to bytes
264  *
265  * @param uuid - UUID represented as string
266  * @param dst - GUID buffer
267  *
268  * @return return 0 on successful conversion
269  */
270 static int string_uuid(char *uuid, u8 *dst)
271 {
272 	efi_guid_t guid;
273 	u16 b, c, d;
274 	u64 e;
275 	u32 a;
276 	u8 *p;
277 	u8 i;
278 
279 	const u8 uuid_str_len = 36;
280 
281 	/* The UUID is written in text: */
282 	/* 1        9    14   19   24 */
283 	/* xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx */
284 
285 	debug("%s: uuid: %s\n", __func__, uuid);
286 
287 	if (strlen(uuid) != uuid_str_len)
288 		return -1;
289 
290 	for (i = 0; i < uuid_str_len; i++) {
291 		if ((i == 8) || (i == 13) || (i == 18) || (i == 23)) {
292 			if (uuid[i] != '-')
293 				return -1;
294 		} else {
295 			if (!isxdigit(uuid[i]))
296 				return -1;
297 		}
298 	}
299 
300 	a = (u32)simple_strtoul(uuid, NULL, 16);
301 	b = (u16)simple_strtoul(uuid + 9, NULL, 16);
302 	c = (u16)simple_strtoul(uuid + 14, NULL, 16);
303 	d = (u16)simple_strtoul(uuid + 19, NULL, 16);
304 	e = (u64)simple_strtoull(uuid + 24, NULL, 16);
305 
306 	p = (u8 *) &e;
307 	guid = EFI_GUID(a, b, c, d >> 8, d & 0xFF,
308 			*(p + 5), *(p + 4), *(p + 3),
309 			*(p + 2), *(p + 1) , *p);
310 
311 	memcpy(dst, guid.b, sizeof(efi_guid_t));
312 
313 	return 0;
314 }
315 
316 int write_gpt_table(block_dev_desc_t *dev_desc,
317 		gpt_header *gpt_h, gpt_entry *gpt_e)
318 {
319 	const int pte_blk_num = (gpt_h->num_partition_entries
320 		* sizeof(gpt_entry)) / dev_desc->blksz;
321 
322 	u32 calc_crc32;
323 	u64 val;
324 
325 	debug("max lba: %x\n", (u32) dev_desc->lba);
326 	/* Setup the Protective MBR */
327 	if (set_protective_mbr(dev_desc) < 0)
328 		goto err;
329 
330 	/* Generate CRC for the Primary GPT Header */
331 	calc_crc32 = efi_crc32((const unsigned char *)gpt_e,
332 			      le32_to_cpu(gpt_h->num_partition_entries) *
333 			      le32_to_cpu(gpt_h->sizeof_partition_entry));
334 	gpt_h->partition_entry_array_crc32 = cpu_to_le32(calc_crc32);
335 
336 	calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
337 			      le32_to_cpu(gpt_h->header_size));
338 	gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
339 
340 	/* Write the First GPT to the block right after the Legacy MBR */
341 	if (dev_desc->block_write(dev_desc->dev, 1, 1, gpt_h) != 1)
342 		goto err;
343 
344 	if (dev_desc->block_write(dev_desc->dev, 2, pte_blk_num, gpt_e)
345 	    != pte_blk_num)
346 		goto err;
347 
348 	/* recalculate the values for the Second GPT Header */
349 	val = le64_to_cpu(gpt_h->my_lba);
350 	gpt_h->my_lba = gpt_h->alternate_lba;
351 	gpt_h->alternate_lba = cpu_to_le64(val);
352 	gpt_h->header_crc32 = 0;
353 
354 	calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
355 			      le32_to_cpu(gpt_h->header_size));
356 	gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
357 
358 	if (dev_desc->block_write(dev_desc->dev,
359 				  le32_to_cpu(gpt_h->last_usable_lba + 1),
360 				  pte_blk_num, gpt_e) != pte_blk_num)
361 		goto err;
362 
363 	if (dev_desc->block_write(dev_desc->dev,
364 				  le32_to_cpu(gpt_h->my_lba), 1, gpt_h) != 1)
365 		goto err;
366 
367 	debug("GPT successfully written to block device!\n");
368 	return 0;
369 
370  err:
371 	printf("** Can't write to device %d **\n", dev_desc->dev);
372 	return -1;
373 }
374 
375 int gpt_fill_pte(gpt_header *gpt_h, gpt_entry *gpt_e,
376 		disk_partition_t *partitions, int parts)
377 {
378 	u32 offset = (u32)le32_to_cpu(gpt_h->first_usable_lba);
379 	ulong start;
380 	int i, k;
381 	size_t name_len;
382 #ifdef CONFIG_PARTITION_UUIDS
383 	char *str_uuid;
384 #endif
385 
386 	for (i = 0; i < parts; i++) {
387 		/* partition starting lba */
388 		start = partitions[i].start;
389 		if (start && (start < offset)) {
390 			printf("Partition overlap\n");
391 			return -1;
392 		}
393 		if (start) {
394 			gpt_e[i].starting_lba = cpu_to_le64(start);
395 			offset = start + partitions[i].size;
396 		} else {
397 			gpt_e[i].starting_lba = cpu_to_le64(offset);
398 			offset += partitions[i].size;
399 		}
400 		if (offset >= gpt_h->last_usable_lba) {
401 			printf("Partitions layout exceds disk size\n");
402 			return -1;
403 		}
404 		/* partition ending lba */
405 		if ((i == parts - 1) && (partitions[i].size == 0))
406 			/* extend the last partition to maximuim */
407 			gpt_e[i].ending_lba = gpt_h->last_usable_lba;
408 		else
409 			gpt_e[i].ending_lba = cpu_to_le64(offset - 1);
410 
411 		/* partition type GUID */
412 		memcpy(gpt_e[i].partition_type_guid.b,
413 			&PARTITION_BASIC_DATA_GUID, 16);
414 
415 #ifdef CONFIG_PARTITION_UUIDS
416 		str_uuid = partitions[i].uuid;
417 		if (string_uuid(str_uuid, gpt_e[i].unique_partition_guid.b)) {
418 			printf("Partition no. %d: invalid guid: %s\n",
419 				i, str_uuid);
420 			return -1;
421 		}
422 #endif
423 
424 		/* partition attributes */
425 		memset(&gpt_e[i].attributes, 0,
426 		       sizeof(gpt_entry_attributes));
427 
428 		/* partition name */
429 		name_len = sizeof(gpt_e[i].partition_name)
430 			/ sizeof(efi_char16_t);
431 		for (k = 0; k < name_len; k++)
432 			gpt_e[i].partition_name[k] =
433 				(efi_char16_t)(partitions[i].name[k]);
434 
435 		debug("%s: name: %s offset[%d]: 0x%x size[%d]: 0x%lx\n",
436 		      __func__, partitions[i].name, i,
437 		      offset, i, partitions[i].size);
438 	}
439 
440 	return 0;
441 }
442 
443 int gpt_fill_header(block_dev_desc_t *dev_desc, gpt_header *gpt_h,
444 		char *str_guid, int parts_count)
445 {
446 	gpt_h->signature = cpu_to_le64(GPT_HEADER_SIGNATURE);
447 	gpt_h->revision = cpu_to_le32(GPT_HEADER_REVISION_V1);
448 	gpt_h->header_size = cpu_to_le32(sizeof(gpt_header));
449 	gpt_h->my_lba = cpu_to_le64(1);
450 	gpt_h->alternate_lba = cpu_to_le64(dev_desc->lba - 1);
451 	gpt_h->first_usable_lba = cpu_to_le64(34);
452 	gpt_h->last_usable_lba = cpu_to_le64(dev_desc->lba - 34);
453 	gpt_h->partition_entry_lba = cpu_to_le64(2);
454 	gpt_h->num_partition_entries = cpu_to_le32(GPT_ENTRY_NUMBERS);
455 	gpt_h->sizeof_partition_entry = cpu_to_le32(sizeof(gpt_entry));
456 	gpt_h->header_crc32 = 0;
457 	gpt_h->partition_entry_array_crc32 = 0;
458 
459 	if (string_uuid(str_guid, gpt_h->disk_guid.b))
460 		return -1;
461 
462 	return 0;
463 }
464 
465 int gpt_restore(block_dev_desc_t *dev_desc, char *str_disk_guid,
466 		disk_partition_t *partitions, int parts_count)
467 {
468 	int ret;
469 
470 	gpt_header *gpt_h = calloc(1, sizeof(gpt_header));
471 	if (gpt_h == NULL) {
472 		printf("%s: calloc failed!\n", __func__);
473 		return -1;
474 	}
475 
476 	gpt_entry *gpt_e = calloc(GPT_ENTRY_NUMBERS, sizeof(gpt_entry));
477 	if (gpt_e == NULL) {
478 		printf("%s: calloc failed!\n", __func__);
479 		free(gpt_h);
480 		return -1;
481 	}
482 
483 	/* Generate Primary GPT header (LBA1) */
484 	ret = gpt_fill_header(dev_desc, gpt_h, str_disk_guid, parts_count);
485 	if (ret)
486 		goto err;
487 
488 	/* Generate partition entries */
489 	ret = gpt_fill_pte(gpt_h, gpt_e, partitions, parts_count);
490 	if (ret)
491 		goto err;
492 
493 	/* Write GPT partition table */
494 	ret = write_gpt_table(dev_desc, gpt_h, gpt_e);
495 
496 err:
497 	free(gpt_e);
498 	free(gpt_h);
499 	return ret;
500 }
501 #endif
502 
503 /*
504  * Private functions
505  */
506 /*
507  * pmbr_part_valid(): Check for EFI partition signature
508  *
509  * Returns: 1 if EFI GPT partition type is found.
510  */
511 static int pmbr_part_valid(struct partition *part)
512 {
513 	if (part->sys_ind == EFI_PMBR_OSTYPE_EFI_GPT &&
514 		le32_to_cpu(part->start_sect) == 1UL) {
515 		return 1;
516 	}
517 
518 	return 0;
519 }
520 
521 /*
522  * is_pmbr_valid(): test Protective MBR for validity
523  *
524  * Returns: 1 if PMBR is valid, 0 otherwise.
525  * Validity depends on two things:
526  *  1) MSDOS signature is in the last two bytes of the MBR
527  *  2) One partition of type 0xEE is found, checked by pmbr_part_valid()
528  */
529 static int is_pmbr_valid(legacy_mbr * mbr)
530 {
531 	int i = 0;
532 
533 	if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
534 		return 0;
535 
536 	for (i = 0; i < 4; i++) {
537 		if (pmbr_part_valid(&mbr->partition_record[i])) {
538 			return 1;
539 		}
540 	}
541 	return 0;
542 }
543 
544 /**
545  * is_gpt_valid() - tests one GPT header and PTEs for validity
546  *
547  * lba is the logical block address of the GPT header to test
548  * gpt is a GPT header ptr, filled on return.
549  * ptes is a PTEs ptr, filled on return.
550  *
551  * Description: returns 1 if valid,  0 on error.
552  * If valid, returns pointers to PTEs.
553  */
554 static int is_gpt_valid(block_dev_desc_t * dev_desc, unsigned long long lba,
555 			gpt_header * pgpt_head, gpt_entry ** pgpt_pte)
556 {
557 	u32 crc32_backup = 0;
558 	u32 calc_crc32;
559 	unsigned long long lastlba;
560 
561 	if (!dev_desc || !pgpt_head) {
562 		printf("%s: Invalid Argument(s)\n", __func__);
563 		return 0;
564 	}
565 
566 	/* Read GPT Header from device */
567 	if (dev_desc->block_read(dev_desc->dev, lba, 1, pgpt_head) != 1) {
568 		printf("*** ERROR: Can't read GPT header ***\n");
569 		return 0;
570 	}
571 
572 	/* Check the GPT header signature */
573 	if (le64_to_cpu(pgpt_head->signature) != GPT_HEADER_SIGNATURE) {
574 		printf("GUID Partition Table Header signature is wrong:"
575 			"0x%llX != 0x%llX\n",
576 			le64_to_cpu(pgpt_head->signature),
577 			GPT_HEADER_SIGNATURE);
578 		return 0;
579 	}
580 
581 	/* Check the GUID Partition Table CRC */
582 	memcpy(&crc32_backup, &pgpt_head->header_crc32, sizeof(crc32_backup));
583 	memset(&pgpt_head->header_crc32, 0, sizeof(pgpt_head->header_crc32));
584 
585 	calc_crc32 = efi_crc32((const unsigned char *)pgpt_head,
586 		le32_to_cpu(pgpt_head->header_size));
587 
588 	memcpy(&pgpt_head->header_crc32, &crc32_backup, sizeof(crc32_backup));
589 
590 	if (calc_crc32 != le32_to_cpu(crc32_backup)) {
591 		printf("GUID Partition Table Header CRC is wrong:"
592 			"0x%x != 0x%x\n",
593 		       le32_to_cpu(crc32_backup), calc_crc32);
594 		return 0;
595 	}
596 
597 	/* Check that the my_lba entry points to the LBA that contains the GPT */
598 	if (le64_to_cpu(pgpt_head->my_lba) != lba) {
599 		printf("GPT: my_lba incorrect: %llX != %llX\n",
600 			le64_to_cpu(pgpt_head->my_lba),
601 			lba);
602 		return 0;
603 	}
604 
605 	/* Check the first_usable_lba and last_usable_lba are within the disk. */
606 	lastlba = (unsigned long long)dev_desc->lba;
607 	if (le64_to_cpu(pgpt_head->first_usable_lba) > lastlba) {
608 		printf("GPT: first_usable_lba incorrect: %llX > %llX\n",
609 			le64_to_cpu(pgpt_head->first_usable_lba), lastlba);
610 		return 0;
611 	}
612 	if (le64_to_cpu(pgpt_head->last_usable_lba) > lastlba) {
613 		printf("GPT: last_usable_lba incorrect: %llX > %llX\n",
614 			(u64) le64_to_cpu(pgpt_head->last_usable_lba), lastlba);
615 		return 0;
616 	}
617 
618 	debug("GPT: first_usable_lba: %llX last_usable_lba %llX last lba %llX\n",
619 		le64_to_cpu(pgpt_head->first_usable_lba),
620 		le64_to_cpu(pgpt_head->last_usable_lba), lastlba);
621 
622 	/* Read and allocate Partition Table Entries */
623 	*pgpt_pte = alloc_read_gpt_entries(dev_desc, pgpt_head);
624 	if (*pgpt_pte == NULL) {
625 		printf("GPT: Failed to allocate memory for PTE\n");
626 		return 0;
627 	}
628 
629 	/* Check the GUID Partition Table Entry Array CRC */
630 	calc_crc32 = efi_crc32((const unsigned char *)*pgpt_pte,
631 		le32_to_cpu(pgpt_head->num_partition_entries) *
632 		le32_to_cpu(pgpt_head->sizeof_partition_entry));
633 
634 	if (calc_crc32 != le32_to_cpu(pgpt_head->partition_entry_array_crc32)) {
635 		printf("GUID Partition Table Entry Array CRC is wrong:"
636 			"0x%x != 0x%x\n",
637 			le32_to_cpu(pgpt_head->partition_entry_array_crc32),
638 			calc_crc32);
639 
640 		free(*pgpt_pte);
641 		return 0;
642 	}
643 
644 	/* We're done, all's well */
645 	return 1;
646 }
647 
648 /**
649  * alloc_read_gpt_entries(): reads partition entries from disk
650  * @dev_desc
651  * @gpt - GPT header
652  *
653  * Description: Returns ptes on success,  NULL on error.
654  * Allocates space for PTEs based on information found in @gpt.
655  * Notes: remember to free pte when you're done!
656  */
657 static gpt_entry *alloc_read_gpt_entries(block_dev_desc_t * dev_desc,
658 					 gpt_header * pgpt_head)
659 {
660 	size_t count = 0;
661 	gpt_entry *pte = NULL;
662 
663 	if (!dev_desc || !pgpt_head) {
664 		printf("%s: Invalid Argument(s)\n", __func__);
665 		return NULL;
666 	}
667 
668 	count = le32_to_cpu(pgpt_head->num_partition_entries) *
669 		le32_to_cpu(pgpt_head->sizeof_partition_entry);
670 
671 	debug("%s: count = %u * %u = %zu\n", __func__,
672 	      (u32) le32_to_cpu(pgpt_head->num_partition_entries),
673 	      (u32) le32_to_cpu(pgpt_head->sizeof_partition_entry), count);
674 
675 	/* Allocate memory for PTE, remember to FREE */
676 	if (count != 0) {
677 		pte = memalign(ARCH_DMA_MINALIGN, count);
678 	}
679 
680 	if (count == 0 || pte == NULL) {
681 		printf("%s: ERROR: Can't allocate 0x%zX "
682 		       "bytes for GPT Entries\n",
683 			__func__, count);
684 		return NULL;
685 	}
686 
687 	/* Read GPT Entries from device */
688 	if (dev_desc->block_read (dev_desc->dev,
689 		le64_to_cpu(pgpt_head->partition_entry_lba),
690 		(lbaint_t) (count / GPT_BLOCK_SIZE), pte)
691 		!= (count / GPT_BLOCK_SIZE)) {
692 
693 		printf("*** ERROR: Can't read GPT Entries ***\n");
694 		free(pte);
695 		return NULL;
696 	}
697 	return pte;
698 }
699 
700 /**
701  * is_pte_valid(): validates a single Partition Table Entry
702  * @gpt_entry - Pointer to a single Partition Table Entry
703  *
704  * Description: returns 1 if valid,  0 on error.
705  */
706 static int is_pte_valid(gpt_entry * pte)
707 {
708 	efi_guid_t unused_guid;
709 
710 	if (!pte) {
711 		printf("%s: Invalid Argument(s)\n", __func__);
712 		return 0;
713 	}
714 
715 	/* Only one validation for now:
716 	 * The GUID Partition Type != Unused Entry (ALL-ZERO)
717 	 */
718 	memset(unused_guid.b, 0, sizeof(unused_guid.b));
719 
720 	if (memcmp(pte->partition_type_guid.b, unused_guid.b,
721 		sizeof(unused_guid.b)) == 0) {
722 
723 		debug("%s: Found an unused PTE GUID at 0x%08X\n", __func__,
724 		      (unsigned int)(uintptr_t)pte);
725 
726 		return 0;
727 	} else {
728 		return 1;
729 	}
730 }
731 #endif
732