xref: /rk3399_rockchip-uboot/disk/part_efi.c (revision dedf37bb61b2a4893f51f7aea2f37fe70d77ab0c)
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 efi_guid_t system_guid = PARTITION_SYSTEM_GUID;
67 
68 static inline int is_bootable(gpt_entry *p)
69 {
70 	return p->attributes.fields.legacy_bios_bootable ||
71 		!memcmp(&(p->partition_type_guid), &system_guid,
72 			sizeof(efi_guid_t));
73 }
74 
75 #ifdef CONFIG_EFI_PARTITION
76 /*
77  * Public Functions (include/part.h)
78  */
79 
80 void print_part_efi(block_dev_desc_t * dev_desc)
81 {
82 	ALLOC_CACHE_ALIGN_BUFFER_PAD(gpt_header, gpt_head, 1, dev_desc->blksz);
83 	gpt_entry *gpt_pte = NULL;
84 	int i = 0;
85 	char uuid[37];
86 	unsigned char *uuid_bin;
87 
88 	if (!dev_desc) {
89 		printf("%s: Invalid Argument(s)\n", __func__);
90 		return;
91 	}
92 	/* This function validates AND fills in the GPT header and PTE */
93 	if (is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA,
94 			 gpt_head, &gpt_pte) != 1) {
95 		printf("%s: *** ERROR: Invalid GPT ***\n", __func__);
96 		if (is_gpt_valid(dev_desc, (dev_desc->lba - 1),
97 				 gpt_head, &gpt_pte) != 1) {
98 			printf("%s: *** ERROR: Invalid Backup GPT ***\n",
99 			       __func__);
100 			return;
101 		} else {
102 			printf("%s: ***        Using Backup GPT ***\n",
103 			       __func__);
104 		}
105 	}
106 
107 	debug("%s: gpt-entry at %p\n", __func__, gpt_pte);
108 
109 	printf("Part\tStart LBA\tEnd LBA\t\tName\n");
110 	printf("\tAttributes\n");
111 	printf("\tType GUID\n");
112 	printf("\tPartition GUID\n");
113 
114 	for (i = 0; i < le32_to_cpu(gpt_head->num_partition_entries); i++) {
115 		/* Stop at the first non valid PTE */
116 		if (!is_pte_valid(&gpt_pte[i]))
117 			break;
118 
119 		printf("%3d\t0x%08llx\t0x%08llx\t\"%s\"\n", (i + 1),
120 			le64_to_cpu(gpt_pte[i].starting_lba),
121 			le64_to_cpu(gpt_pte[i].ending_lba),
122 			print_efiname(&gpt_pte[i]));
123 		printf("\tattrs:\t0x%016llx\n", gpt_pte[i].attributes.raw);
124 		uuid_bin = (unsigned char *)gpt_pte[i].partition_type_guid.b;
125 		uuid_bin_to_str(uuid_bin, uuid, UUID_STR_FORMAT_GUID);
126 		printf("\ttype:\t%s\n", uuid);
127 		uuid_bin = (unsigned char *)gpt_pte[i].unique_partition_guid.b;
128 		uuid_bin_to_str(uuid_bin, uuid, UUID_STR_FORMAT_GUID);
129 		printf("\tguid:\t%s\n", uuid);
130 	}
131 
132 	/* Remember to free pte */
133 	free(gpt_pte);
134 	return;
135 }
136 
137 int get_partition_info_efi(block_dev_desc_t * dev_desc, int part,
138 				disk_partition_t * info)
139 {
140 	ALLOC_CACHE_ALIGN_BUFFER_PAD(gpt_header, gpt_head, 1, dev_desc->blksz);
141 	gpt_entry *gpt_pte = NULL;
142 
143 	/* "part" argument must be at least 1 */
144 	if (!dev_desc || !info || part < 1) {
145 		printf("%s: Invalid Argument(s)\n", __func__);
146 		return -1;
147 	}
148 
149 	/* This function validates AND fills in the GPT header and PTE */
150 	if (is_gpt_valid(dev_desc, GPT_PRIMARY_PARTITION_TABLE_LBA,
151 			gpt_head, &gpt_pte) != 1) {
152 		printf("%s: *** ERROR: Invalid GPT ***\n", __func__);
153 		if (is_gpt_valid(dev_desc, (dev_desc->lba - 1),
154 				 gpt_head, &gpt_pte) != 1) {
155 			printf("%s: *** ERROR: Invalid Backup GPT ***\n",
156 			       __func__);
157 			return -1;
158 		} else {
159 			printf("%s: ***        Using Backup GPT ***\n",
160 			       __func__);
161 		}
162 	}
163 
164 	if (part > le32_to_cpu(gpt_head->num_partition_entries) ||
165 	    !is_pte_valid(&gpt_pte[part - 1])) {
166 		debug("%s: *** ERROR: Invalid partition number %d ***\n",
167 			__func__, part);
168 		free(gpt_pte);
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_bin_to_str(gpt_pte[part - 1].unique_partition_guid.b, info->uuid,
185 			UUID_STR_FORMAT_GUID);
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 	/* Setup the Protective MBR */
217 	ALLOC_CACHE_ALIGN_BUFFER(legacy_mbr, p_mbr, 1);
218 	memset(p_mbr, 0, sizeof(*p_mbr));
219 
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 		return -1;
235 	}
236 
237 	return 0;
238 }
239 
240 int write_gpt_table(block_dev_desc_t *dev_desc,
241 		gpt_header *gpt_h, gpt_entry *gpt_e)
242 {
243 	const int pte_blk_cnt = BLOCK_CNT((gpt_h->num_partition_entries
244 					   * sizeof(gpt_entry)), dev_desc);
245 	u32 calc_crc32;
246 	u64 val;
247 
248 	debug("max lba: %x\n", (u32) dev_desc->lba);
249 	/* Setup the Protective MBR */
250 	if (set_protective_mbr(dev_desc) < 0)
251 		goto err;
252 
253 	/* Generate CRC for the Primary GPT Header */
254 	calc_crc32 = efi_crc32((const unsigned char *)gpt_e,
255 			      le32_to_cpu(gpt_h->num_partition_entries) *
256 			      le32_to_cpu(gpt_h->sizeof_partition_entry));
257 	gpt_h->partition_entry_array_crc32 = cpu_to_le32(calc_crc32);
258 
259 	calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
260 			      le32_to_cpu(gpt_h->header_size));
261 	gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
262 
263 	/* Write the First GPT to the block right after the Legacy MBR */
264 	if (dev_desc->block_write(dev_desc->dev, 1, 1, gpt_h) != 1)
265 		goto err;
266 
267 	if (dev_desc->block_write(dev_desc->dev, 2, pte_blk_cnt, gpt_e)
268 	    != pte_blk_cnt)
269 		goto err;
270 
271 	/* recalculate the values for the Backup GPT Header */
272 	val = le64_to_cpu(gpt_h->my_lba);
273 	gpt_h->my_lba = gpt_h->alternate_lba;
274 	gpt_h->alternate_lba = cpu_to_le64(val);
275 	gpt_h->header_crc32 = 0;
276 
277 	calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
278 			      le32_to_cpu(gpt_h->header_size));
279 	gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
280 
281 	if (dev_desc->block_write(dev_desc->dev,
282 				  le32_to_cpu(gpt_h->last_usable_lba) + 1,
283 				  pte_blk_cnt, gpt_e) != pte_blk_cnt)
284 		goto err;
285 
286 	if (dev_desc->block_write(dev_desc->dev,
287 				  le32_to_cpu(gpt_h->my_lba), 1, gpt_h) != 1)
288 		goto err;
289 
290 	debug("GPT successfully written to block device!\n");
291 	return 0;
292 
293  err:
294 	printf("** Can't write to device %d **\n", dev_desc->dev);
295 	return -1;
296 }
297 
298 int gpt_fill_pte(gpt_header *gpt_h, gpt_entry *gpt_e,
299 		disk_partition_t *partitions, int parts)
300 {
301 	u32 offset = (u32)le32_to_cpu(gpt_h->first_usable_lba);
302 	ulong start;
303 	u32 last_usable_lba = (u32)le32_to_cpu(gpt_h->last_usable_lba);
304 	int i, k;
305 	size_t efiname_len, dosname_len;
306 #ifdef CONFIG_PARTITION_UUIDS
307 	char *str_uuid;
308 	unsigned char *bin_uuid;
309 #endif
310 
311 	for (i = 0; i < parts; i++) {
312 		/* partition starting lba */
313 		start = partitions[i].start;
314 		if (start && (start < offset)) {
315 			printf("Partition overlap\n");
316 			return -1;
317 		}
318 		if (start) {
319 			gpt_e[i].starting_lba = cpu_to_le64(start);
320 			offset = start + partitions[i].size;
321 		} else {
322 			gpt_e[i].starting_lba = cpu_to_le64(offset);
323 			offset += partitions[i].size;
324 		}
325 		if (offset >= last_usable_lba) {
326 			printf("Partitions layout exceds disk size\n");
327 			return -1;
328 		}
329 		/* partition ending lba */
330 		if ((i == parts - 1) && (partitions[i].size == 0))
331 			/* extend the last partition to maximuim */
332 			gpt_e[i].ending_lba = gpt_h->last_usable_lba;
333 		else
334 			gpt_e[i].ending_lba = cpu_to_le64(offset - 1);
335 
336 		/* partition type GUID */
337 		memcpy(gpt_e[i].partition_type_guid.b,
338 			&PARTITION_BASIC_DATA_GUID, 16);
339 
340 #ifdef CONFIG_PARTITION_UUIDS
341 		str_uuid = partitions[i].uuid;
342 		bin_uuid = gpt_e[i].unique_partition_guid.b;
343 
344 		if (uuid_str_to_bin(str_uuid, bin_uuid, UUID_STR_FORMAT_STD)) {
345 			printf("Partition no. %d: invalid guid: %s\n",
346 				i, str_uuid);
347 			return -1;
348 		}
349 #endif
350 
351 		/* partition attributes */
352 		memset(&gpt_e[i].attributes, 0,
353 		       sizeof(gpt_entry_attributes));
354 
355 		/* partition name */
356 		efiname_len = sizeof(gpt_e[i].partition_name)
357 			/ sizeof(efi_char16_t);
358 		dosname_len = sizeof(partitions[i].name);
359 
360 		memset(gpt_e[i].partition_name, 0,
361 		       sizeof(gpt_e[i].partition_name));
362 
363 		for (k = 0; k < min(dosname_len, efiname_len); k++)
364 			gpt_e[i].partition_name[k] =
365 				(efi_char16_t)(partitions[i].name[k]);
366 
367 		debug("%s: name: %s offset[%d]: 0x%x size[%d]: 0x" LBAF "\n",
368 		      __func__, partitions[i].name, i,
369 		      offset, i, partitions[i].size);
370 	}
371 
372 	return 0;
373 }
374 
375 int gpt_fill_header(block_dev_desc_t *dev_desc, gpt_header *gpt_h,
376 		char *str_guid, int parts_count)
377 {
378 	gpt_h->signature = cpu_to_le64(GPT_HEADER_SIGNATURE);
379 	gpt_h->revision = cpu_to_le32(GPT_HEADER_REVISION_V1);
380 	gpt_h->header_size = cpu_to_le32(sizeof(gpt_header));
381 	gpt_h->my_lba = cpu_to_le64(1);
382 	gpt_h->alternate_lba = cpu_to_le64(dev_desc->lba - 1);
383 	gpt_h->first_usable_lba = cpu_to_le64(34);
384 	gpt_h->last_usable_lba = cpu_to_le64(dev_desc->lba - 34);
385 	gpt_h->partition_entry_lba = cpu_to_le64(2);
386 	gpt_h->num_partition_entries = cpu_to_le32(GPT_ENTRY_NUMBERS);
387 	gpt_h->sizeof_partition_entry = cpu_to_le32(sizeof(gpt_entry));
388 	gpt_h->header_crc32 = 0;
389 	gpt_h->partition_entry_array_crc32 = 0;
390 
391 	if (uuid_str_to_bin(str_guid, gpt_h->disk_guid.b, UUID_STR_FORMAT_GUID))
392 		return -1;
393 
394 	return 0;
395 }
396 
397 int gpt_restore(block_dev_desc_t *dev_desc, char *str_disk_guid,
398 		disk_partition_t *partitions, int parts_count)
399 {
400 	int ret;
401 
402 	gpt_header *gpt_h = calloc(1, PAD_TO_BLOCKSIZE(sizeof(gpt_header),
403 						       dev_desc));
404 	gpt_entry *gpt_e;
405 
406 	if (gpt_h == NULL) {
407 		printf("%s: calloc failed!\n", __func__);
408 		return -1;
409 	}
410 
411 	gpt_e = calloc(1, PAD_TO_BLOCKSIZE(GPT_ENTRY_NUMBERS
412 					       * sizeof(gpt_entry),
413 					       dev_desc));
414 	if (gpt_e == NULL) {
415 		printf("%s: calloc failed!\n", __func__);
416 		free(gpt_h);
417 		return -1;
418 	}
419 
420 	/* Generate Primary GPT header (LBA1) */
421 	ret = gpt_fill_header(dev_desc, gpt_h, str_disk_guid, parts_count);
422 	if (ret)
423 		goto err;
424 
425 	/* Generate partition entries */
426 	ret = gpt_fill_pte(gpt_h, gpt_e, partitions, parts_count);
427 	if (ret)
428 		goto err;
429 
430 	/* Write GPT partition table */
431 	ret = write_gpt_table(dev_desc, gpt_h, gpt_e);
432 
433 err:
434 	free(gpt_e);
435 	free(gpt_h);
436 	return ret;
437 }
438 #endif
439 
440 /*
441  * Private functions
442  */
443 /*
444  * pmbr_part_valid(): Check for EFI partition signature
445  *
446  * Returns: 1 if EFI GPT partition type is found.
447  */
448 static int pmbr_part_valid(struct partition *part)
449 {
450 	if (part->sys_ind == EFI_PMBR_OSTYPE_EFI_GPT &&
451 		get_unaligned_le32(&part->start_sect) == 1UL) {
452 		return 1;
453 	}
454 
455 	return 0;
456 }
457 
458 /*
459  * is_pmbr_valid(): test Protective MBR for validity
460  *
461  * Returns: 1 if PMBR is valid, 0 otherwise.
462  * Validity depends on two things:
463  *  1) MSDOS signature is in the last two bytes of the MBR
464  *  2) One partition of type 0xEE is found, checked by pmbr_part_valid()
465  */
466 static int is_pmbr_valid(legacy_mbr * mbr)
467 {
468 	int i = 0;
469 
470 	if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
471 		return 0;
472 
473 	for (i = 0; i < 4; i++) {
474 		if (pmbr_part_valid(&mbr->partition_record[i])) {
475 			return 1;
476 		}
477 	}
478 	return 0;
479 }
480 
481 /**
482  * is_gpt_valid() - tests one GPT header and PTEs for validity
483  *
484  * lba is the logical block address of the GPT header to test
485  * gpt is a GPT header ptr, filled on return.
486  * ptes is a PTEs ptr, filled on return.
487  *
488  * Description: returns 1 if valid,  0 on error.
489  * If valid, returns pointers to PTEs.
490  */
491 static int is_gpt_valid(block_dev_desc_t * dev_desc, unsigned long long lba,
492 			gpt_header * pgpt_head, gpt_entry ** pgpt_pte)
493 {
494 	u32 crc32_backup = 0;
495 	u32 calc_crc32;
496 	unsigned long long lastlba;
497 
498 	if (!dev_desc || !pgpt_head) {
499 		printf("%s: Invalid Argument(s)\n", __func__);
500 		return 0;
501 	}
502 
503 	/* Read GPT Header from device */
504 	if (dev_desc->block_read(dev_desc->dev, lba, 1, pgpt_head) != 1) {
505 		printf("*** ERROR: Can't read GPT header ***\n");
506 		return 0;
507 	}
508 
509 	/* Check the GPT header signature */
510 	if (le64_to_cpu(pgpt_head->signature) != GPT_HEADER_SIGNATURE) {
511 		printf("GUID Partition Table Header signature is wrong:"
512 			"0x%llX != 0x%llX\n",
513 			le64_to_cpu(pgpt_head->signature),
514 			GPT_HEADER_SIGNATURE);
515 		return 0;
516 	}
517 
518 	/* Check the GUID Partition Table CRC */
519 	memcpy(&crc32_backup, &pgpt_head->header_crc32, sizeof(crc32_backup));
520 	memset(&pgpt_head->header_crc32, 0, sizeof(pgpt_head->header_crc32));
521 
522 	calc_crc32 = efi_crc32((const unsigned char *)pgpt_head,
523 		le32_to_cpu(pgpt_head->header_size));
524 
525 	memcpy(&pgpt_head->header_crc32, &crc32_backup, sizeof(crc32_backup));
526 
527 	if (calc_crc32 != le32_to_cpu(crc32_backup)) {
528 		printf("GUID Partition Table Header CRC is wrong:"
529 			"0x%x != 0x%x\n",
530 		       le32_to_cpu(crc32_backup), calc_crc32);
531 		return 0;
532 	}
533 
534 	/* Check that the my_lba entry points to the LBA that contains the GPT */
535 	if (le64_to_cpu(pgpt_head->my_lba) != lba) {
536 		printf("GPT: my_lba incorrect: %llX != %llX\n",
537 			le64_to_cpu(pgpt_head->my_lba),
538 			lba);
539 		return 0;
540 	}
541 
542 	/* Check the first_usable_lba and last_usable_lba are within the disk. */
543 	lastlba = (unsigned long long)dev_desc->lba;
544 	if (le64_to_cpu(pgpt_head->first_usable_lba) > lastlba) {
545 		printf("GPT: first_usable_lba incorrect: %llX > %llX\n",
546 			le64_to_cpu(pgpt_head->first_usable_lba), lastlba);
547 		return 0;
548 	}
549 	if (le64_to_cpu(pgpt_head->last_usable_lba) > lastlba) {
550 		printf("GPT: last_usable_lba incorrect: %llX > %llX\n",
551 			(u64) le64_to_cpu(pgpt_head->last_usable_lba), lastlba);
552 		return 0;
553 	}
554 
555 	debug("GPT: first_usable_lba: %llX last_usable_lba %llX last lba %llX\n",
556 		le64_to_cpu(pgpt_head->first_usable_lba),
557 		le64_to_cpu(pgpt_head->last_usable_lba), lastlba);
558 
559 	/* Read and allocate Partition Table Entries */
560 	*pgpt_pte = alloc_read_gpt_entries(dev_desc, pgpt_head);
561 	if (*pgpt_pte == NULL) {
562 		printf("GPT: Failed to allocate memory for PTE\n");
563 		return 0;
564 	}
565 
566 	/* Check the GUID Partition Table Entry Array CRC */
567 	calc_crc32 = efi_crc32((const unsigned char *)*pgpt_pte,
568 		le32_to_cpu(pgpt_head->num_partition_entries) *
569 		le32_to_cpu(pgpt_head->sizeof_partition_entry));
570 
571 	if (calc_crc32 != le32_to_cpu(pgpt_head->partition_entry_array_crc32)) {
572 		printf("GUID Partition Table Entry Array CRC is wrong:"
573 			"0x%x != 0x%x\n",
574 			le32_to_cpu(pgpt_head->partition_entry_array_crc32),
575 			calc_crc32);
576 
577 		free(*pgpt_pte);
578 		return 0;
579 	}
580 
581 	/* We're done, all's well */
582 	return 1;
583 }
584 
585 /**
586  * alloc_read_gpt_entries(): reads partition entries from disk
587  * @dev_desc
588  * @gpt - GPT header
589  *
590  * Description: Returns ptes on success,  NULL on error.
591  * Allocates space for PTEs based on information found in @gpt.
592  * Notes: remember to free pte when you're done!
593  */
594 static gpt_entry *alloc_read_gpt_entries(block_dev_desc_t * dev_desc,
595 					 gpt_header * pgpt_head)
596 {
597 	size_t count = 0, blk_cnt;
598 	gpt_entry *pte = NULL;
599 
600 	if (!dev_desc || !pgpt_head) {
601 		printf("%s: Invalid Argument(s)\n", __func__);
602 		return NULL;
603 	}
604 
605 	count = le32_to_cpu(pgpt_head->num_partition_entries) *
606 		le32_to_cpu(pgpt_head->sizeof_partition_entry);
607 
608 	debug("%s: count = %u * %u = %zu\n", __func__,
609 	      (u32) le32_to_cpu(pgpt_head->num_partition_entries),
610 	      (u32) le32_to_cpu(pgpt_head->sizeof_partition_entry), count);
611 
612 	/* Allocate memory for PTE, remember to FREE */
613 	if (count != 0) {
614 		pte = memalign(ARCH_DMA_MINALIGN,
615 			       PAD_TO_BLOCKSIZE(count, dev_desc));
616 	}
617 
618 	if (count == 0 || pte == NULL) {
619 		printf("%s: ERROR: Can't allocate 0x%zX "
620 		       "bytes for GPT Entries\n",
621 			__func__, count);
622 		return NULL;
623 	}
624 
625 	/* Read GPT Entries from device */
626 	blk_cnt = BLOCK_CNT(count, dev_desc);
627 	if (dev_desc->block_read (dev_desc->dev,
628 		le64_to_cpu(pgpt_head->partition_entry_lba),
629 		(lbaint_t) (blk_cnt), pte)
630 		!= blk_cnt) {
631 
632 		printf("*** ERROR: Can't read GPT Entries ***\n");
633 		free(pte);
634 		return NULL;
635 	}
636 	return pte;
637 }
638 
639 /**
640  * is_pte_valid(): validates a single Partition Table Entry
641  * @gpt_entry - Pointer to a single Partition Table Entry
642  *
643  * Description: returns 1 if valid,  0 on error.
644  */
645 static int is_pte_valid(gpt_entry * pte)
646 {
647 	efi_guid_t unused_guid;
648 
649 	if (!pte) {
650 		printf("%s: Invalid Argument(s)\n", __func__);
651 		return 0;
652 	}
653 
654 	/* Only one validation for now:
655 	 * The GUID Partition Type != Unused Entry (ALL-ZERO)
656 	 */
657 	memset(unused_guid.b, 0, sizeof(unused_guid.b));
658 
659 	if (memcmp(pte->partition_type_guid.b, unused_guid.b,
660 		sizeof(unused_guid.b)) == 0) {
661 
662 		debug("%s: Found an unused PTE GUID at 0x%08X\n", __func__,
663 		      (unsigned int)(uintptr_t)pte);
664 
665 		return 0;
666 	} else {
667 		return 1;
668 	}
669 }
670 #endif
671