1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * EFI device path from u-boot device-model mapping
4  *
5  * (C) Copyright 2017 Rob Clark
6  */
7 
8 #define LOG_CATEGORY LOGL_ERR
9 
10 #include <common.h>
11 #include <blk.h>
12 #include <dm.h>
13 #include <usb.h>
14 #include <mmc.h>
15 #include <efi_loader.h>
16 #include <part.h>
17 
18 /* template END node: */
19 static const struct efi_device_path END = {
20 	.type     = DEVICE_PATH_TYPE_END,
21 	.sub_type = DEVICE_PATH_SUB_TYPE_END,
22 	.length   = sizeof(END),
23 };
24 
25 #define U_BOOT_GUID \
26 	EFI_GUID(0xe61d73b9, 0xa384, 0x4acc, \
27 		 0xae, 0xab, 0x82, 0xe8, 0x28, 0xf3, 0x62, 0x8b)
28 
29 /* template ROOT node: */
30 static const struct efi_device_path_vendor ROOT = {
31 	.dp = {
32 		.type     = DEVICE_PATH_TYPE_HARDWARE_DEVICE,
33 		.sub_type = DEVICE_PATH_SUB_TYPE_VENDOR,
34 		.length   = sizeof(ROOT),
35 	},
36 	.guid = U_BOOT_GUID,
37 };
38 
39 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
40 /*
41  * Determine if an MMC device is an SD card.
42  *
43  * @desc	block device descriptor
44  * @return	true if the device is an SD card
45  */
46 static bool is_sd(struct blk_desc *desc)
47 {
48 	struct mmc *mmc = find_mmc_device(desc->devnum);
49 
50 	if (!mmc)
51 		return false;
52 
53 	return IS_SD(mmc) != 0U;
54 }
55 #endif
56 
57 static void *dp_alloc(size_t sz)
58 {
59 	void *buf;
60 
61 	if (efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, sz, &buf) !=
62 	    EFI_SUCCESS) {
63 		debug("EFI: ERROR: out of memory in %s\n", __func__);
64 		return NULL;
65 	}
66 
67 	memset(buf, 0, sz);
68 	return buf;
69 }
70 
71 /*
72  * Iterate to next block in device-path, terminating (returning NULL)
73  * at /End* node.
74  */
75 struct efi_device_path *efi_dp_next(const struct efi_device_path *dp)
76 {
77 	if (dp == NULL)
78 		return NULL;
79 	if (dp->type == DEVICE_PATH_TYPE_END)
80 		return NULL;
81 	dp = ((void *)dp) + dp->length;
82 	if (dp->type == DEVICE_PATH_TYPE_END)
83 		return NULL;
84 	return (struct efi_device_path *)dp;
85 }
86 
87 /*
88  * Compare two device-paths, stopping when the shorter of the two hits
89  * an End* node.  This is useful to, for example, compare a device-path
90  * representing a device with one representing a file on the device, or
91  * a device with a parent device.
92  */
93 int efi_dp_match(const struct efi_device_path *a,
94 		 const struct efi_device_path *b)
95 {
96 	while (1) {
97 		int ret;
98 
99 		ret = memcmp(&a->length, &b->length, sizeof(a->length));
100 		if (ret)
101 			return ret;
102 
103 		ret = memcmp(a, b, a->length);
104 		if (ret)
105 			return ret;
106 
107 		a = efi_dp_next(a);
108 		b = efi_dp_next(b);
109 
110 		if (!a || !b)
111 			return 0;
112 	}
113 }
114 
115 /*
116  * See UEFI spec (section 3.1.2, about short-form device-paths..
117  * tl;dr: we can have a device-path that starts with a USB WWID
118  * or USB Class node, and a few other cases which don't encode
119  * the full device path with bus hierarchy:
120  *
121  *   - MESSAGING:USB_WWID
122  *   - MESSAGING:USB_CLASS
123  *   - MEDIA:FILE_PATH
124  *   - MEDIA:HARD_DRIVE
125  *   - MESSAGING:URI
126  */
127 static struct efi_device_path *shorten_path(struct efi_device_path *dp)
128 {
129 	while (dp) {
130 		/*
131 		 * TODO: Add MESSAGING:USB_WWID and MESSAGING:URI..
132 		 * in practice fallback.efi just uses MEDIA:HARD_DRIVE
133 		 * so not sure when we would see these other cases.
134 		 */
135 		if (EFI_DP_TYPE(dp, MESSAGING_DEVICE, MSG_USB_CLASS) ||
136 		    EFI_DP_TYPE(dp, MEDIA_DEVICE, HARD_DRIVE_PATH) ||
137 		    EFI_DP_TYPE(dp, MEDIA_DEVICE, FILE_PATH))
138 			return dp;
139 
140 		dp = efi_dp_next(dp);
141 	}
142 
143 	return dp;
144 }
145 
146 static struct efi_object *find_obj(struct efi_device_path *dp, bool short_path,
147 				   struct efi_device_path **rem)
148 {
149 	struct efi_object *efiobj;
150 	efi_uintn_t dp_size = efi_dp_instance_size(dp);
151 
152 	list_for_each_entry(efiobj, &efi_obj_list, link) {
153 		struct efi_handler *handler;
154 		struct efi_device_path *obj_dp;
155 		efi_status_t ret;
156 
157 		ret = efi_search_protocol(efiobj->handle,
158 					  &efi_guid_device_path, &handler);
159 		if (ret != EFI_SUCCESS)
160 			continue;
161 		obj_dp = handler->protocol_interface;
162 
163 		do {
164 			if (efi_dp_match(dp, obj_dp) == 0) {
165 				if (rem) {
166 					/*
167 					 * Allow partial matches, but inform
168 					 * the caller.
169 					 */
170 					*rem = ((void *)dp) +
171 						efi_dp_instance_size(obj_dp);
172 					return efiobj;
173 				} else {
174 					/* Only return on exact matches */
175 					if (efi_dp_instance_size(obj_dp) ==
176 					    dp_size)
177 						return efiobj;
178 				}
179 			}
180 
181 			obj_dp = shorten_path(efi_dp_next(obj_dp));
182 		} while (short_path && obj_dp);
183 	}
184 
185 	return NULL;
186 }
187 
188 /*
189  * Find an efiobj from device-path, if 'rem' is not NULL, returns the
190  * remaining part of the device path after the matched object.
191  */
192 struct efi_object *efi_dp_find_obj(struct efi_device_path *dp,
193 				   struct efi_device_path **rem)
194 {
195 	struct efi_object *efiobj;
196 
197 	/* Search for an exact match first */
198 	efiobj = find_obj(dp, false, NULL);
199 
200 	/* Then for a fuzzy match */
201 	if (!efiobj)
202 		efiobj = find_obj(dp, false, rem);
203 
204 	/* And now for a fuzzy short match */
205 	if (!efiobj)
206 		efiobj = find_obj(dp, true, rem);
207 
208 	return efiobj;
209 }
210 
211 /*
212  * Determine the last device path node that is not the end node.
213  *
214  * @dp		device path
215  * @return	last node before the end node if it exists
216  *		otherwise NULL
217  */
218 const struct efi_device_path *efi_dp_last_node(const struct efi_device_path *dp)
219 {
220 	struct efi_device_path *ret;
221 
222 	if (!dp || dp->type == DEVICE_PATH_TYPE_END)
223 		return NULL;
224 	while (dp) {
225 		ret = (struct efi_device_path *)dp;
226 		dp = efi_dp_next(dp);
227 	}
228 	return ret;
229 }
230 
231 /* get size of the first device path instance excluding end node */
232 efi_uintn_t efi_dp_instance_size(const struct efi_device_path *dp)
233 {
234 	efi_uintn_t sz = 0;
235 
236 	if (!dp || dp->type == DEVICE_PATH_TYPE_END)
237 		return 0;
238 	while (dp) {
239 		sz += dp->length;
240 		dp = efi_dp_next(dp);
241 	}
242 
243 	return sz;
244 }
245 
246 /* get size of multi-instance device path excluding end node */
247 efi_uintn_t efi_dp_size(const struct efi_device_path *dp)
248 {
249 	const struct efi_device_path *p = dp;
250 
251 	if (!p)
252 		return 0;
253 	while (p->type != DEVICE_PATH_TYPE_END ||
254 	       p->sub_type != DEVICE_PATH_SUB_TYPE_END)
255 		p = (void *)p + p->length;
256 
257 	return (void *)p - (void *)dp;
258 }
259 
260 /* copy multi-instance device path */
261 struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp)
262 {
263 	struct efi_device_path *ndp;
264 	size_t sz = efi_dp_size(dp) + sizeof(END);
265 
266 	if (!dp)
267 		return NULL;
268 
269 	ndp = dp_alloc(sz);
270 	if (!ndp)
271 		return NULL;
272 	memcpy(ndp, dp, sz);
273 
274 	return ndp;
275 }
276 
277 struct efi_device_path *efi_dp_append(const struct efi_device_path *dp1,
278 				      const struct efi_device_path *dp2)
279 {
280 	struct efi_device_path *ret;
281 
282 	if (!dp1 && !dp2) {
283 		/* return an end node */
284 		ret = efi_dp_dup(&END);
285 	} else if (!dp1) {
286 		ret = efi_dp_dup(dp2);
287 	} else if (!dp2) {
288 		ret = efi_dp_dup(dp1);
289 	} else {
290 		/* both dp1 and dp2 are non-null */
291 		unsigned sz1 = efi_dp_size(dp1);
292 		unsigned sz2 = efi_dp_size(dp2);
293 		void *p = dp_alloc(sz1 + sz2 + sizeof(END));
294 		if (!p)
295 			return NULL;
296 		memcpy(p, dp1, sz1);
297 		/* the end node of the second device path has to be retained */
298 		memcpy(p + sz1, dp2, sz2 + sizeof(END));
299 		ret = p;
300 	}
301 
302 	return ret;
303 }
304 
305 struct efi_device_path *efi_dp_append_node(const struct efi_device_path *dp,
306 					   const struct efi_device_path *node)
307 {
308 	struct efi_device_path *ret;
309 
310 	if (!node && !dp) {
311 		ret = efi_dp_dup(&END);
312 	} else if (!node) {
313 		ret = efi_dp_dup(dp);
314 	} else if (!dp) {
315 		size_t sz = node->length;
316 		void *p = dp_alloc(sz + sizeof(END));
317 		if (!p)
318 			return NULL;
319 		memcpy(p, node, sz);
320 		memcpy(p + sz, &END, sizeof(END));
321 		ret = p;
322 	} else {
323 		/* both dp and node are non-null */
324 		size_t sz = efi_dp_size(dp);
325 		void *p = dp_alloc(sz + node->length + sizeof(END));
326 		if (!p)
327 			return NULL;
328 		memcpy(p, dp, sz);
329 		memcpy(p + sz, node, node->length);
330 		memcpy(p + sz + node->length, &END, sizeof(END));
331 		ret = p;
332 	}
333 
334 	return ret;
335 }
336 
337 struct efi_device_path *efi_dp_create_device_node(const u8 type,
338 						  const u8 sub_type,
339 						  const u16 length)
340 {
341 	struct efi_device_path *ret;
342 
343 	ret = dp_alloc(length);
344 	if (!ret)
345 		return ret;
346 	ret->type = type;
347 	ret->sub_type = sub_type;
348 	ret->length = length;
349 	return ret;
350 }
351 
352 struct efi_device_path *efi_dp_append_instance(
353 		const struct efi_device_path *dp,
354 		const struct efi_device_path *dpi)
355 {
356 	size_t sz, szi;
357 	struct efi_device_path *p, *ret;
358 
359 	if (!dpi)
360 		return NULL;
361 	if (!dp)
362 		return efi_dp_dup(dpi);
363 	sz = efi_dp_size(dp);
364 	szi = efi_dp_instance_size(dpi);
365 	p = dp_alloc(sz + szi + 2 * sizeof(END));
366 	if (!p)
367 		return NULL;
368 	ret = p;
369 	memcpy(p, dp, sz + sizeof(END));
370 	p = (void *)p + sz;
371 	p->sub_type = DEVICE_PATH_SUB_TYPE_INSTANCE_END;
372 	p = (void *)p + sizeof(END);
373 	memcpy(p, dpi, szi);
374 	p = (void *)p + szi;
375 	memcpy(p, &END, sizeof(END));
376 	return ret;
377 }
378 
379 struct efi_device_path *efi_dp_get_next_instance(struct efi_device_path **dp,
380 						 efi_uintn_t *size)
381 {
382 	size_t sz;
383 	struct efi_device_path *p;
384 
385 	if (size)
386 		*size = 0;
387 	if (!dp || !*dp)
388 		return NULL;
389 	p = *dp;
390 	sz = efi_dp_instance_size(*dp);
391 	p = dp_alloc(sz + sizeof(END));
392 	if (!p)
393 		return NULL;
394 	memcpy(p, *dp, sz + sizeof(END));
395 	*dp = (void *)*dp + sz;
396 	if ((*dp)->sub_type == DEVICE_PATH_SUB_TYPE_INSTANCE_END)
397 		*dp = (void *)*dp + sizeof(END);
398 	else
399 		*dp = NULL;
400 	if (size)
401 		*size = sz + sizeof(END);
402 	return p;
403 }
404 
405 bool efi_dp_is_multi_instance(const struct efi_device_path *dp)
406 {
407 	const struct efi_device_path *p = dp;
408 
409 	if (!p)
410 		return false;
411 	while (p->type != DEVICE_PATH_TYPE_END)
412 		p = (void *)p + p->length;
413 	return p->sub_type == DEVICE_PATH_SUB_TYPE_INSTANCE_END;
414 }
415 
416 #ifdef CONFIG_DM
417 /* size of device-path not including END node for device and all parents
418  * up to the root device.
419  */
420 static unsigned dp_size(struct udevice *dev)
421 {
422 	if (!dev || !dev->driver)
423 		return sizeof(ROOT);
424 
425 	switch (dev->driver->id) {
426 	case UCLASS_ROOT:
427 	case UCLASS_SIMPLE_BUS:
428 		/* stop traversing parents at this point: */
429 		return sizeof(ROOT);
430 	case UCLASS_ETH:
431 		return dp_size(dev->parent) +
432 			sizeof(struct efi_device_path_mac_addr);
433 #ifdef CONFIG_BLK
434 	case UCLASS_BLK:
435 		switch (dev->parent->uclass->uc_drv->id) {
436 #ifdef CONFIG_IDE
437 		case UCLASS_IDE:
438 			return dp_size(dev->parent) +
439 				sizeof(struct efi_device_path_atapi);
440 #endif
441 #if defined(CONFIG_SCSI) && defined(CONFIG_DM_SCSI)
442 		case UCLASS_SCSI:
443 			return dp_size(dev->parent) +
444 				sizeof(struct efi_device_path_scsi);
445 #endif
446 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
447 		case UCLASS_MMC:
448 			return dp_size(dev->parent) +
449 				sizeof(struct efi_device_path_sd_mmc_path);
450 #endif
451 		default:
452 			return dp_size(dev->parent);
453 		}
454 #endif
455 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
456 	case UCLASS_MMC:
457 		return dp_size(dev->parent) +
458 			sizeof(struct efi_device_path_sd_mmc_path);
459 #endif
460 	case UCLASS_MASS_STORAGE:
461 	case UCLASS_USB_HUB:
462 		return dp_size(dev->parent) +
463 			sizeof(struct efi_device_path_usb_class);
464 	default:
465 		/* just skip over unknown classes: */
466 		return dp_size(dev->parent);
467 	}
468 }
469 
470 /*
471  * Recursively build a device path.
472  *
473  * @buf		pointer to the end of the device path
474  * @dev		device
475  * @return	pointer to the end of the device path
476  */
477 static void *dp_fill(void *buf, struct udevice *dev)
478 {
479 	if (!dev || !dev->driver)
480 		return buf;
481 
482 	switch (dev->driver->id) {
483 	case UCLASS_ROOT:
484 	case UCLASS_SIMPLE_BUS: {
485 		/* stop traversing parents at this point: */
486 		struct efi_device_path_vendor *vdp = buf;
487 		*vdp = ROOT;
488 		return &vdp[1];
489 	}
490 #ifdef CONFIG_DM_ETH
491 	case UCLASS_ETH: {
492 		struct efi_device_path_mac_addr *dp =
493 			dp_fill(buf, dev->parent);
494 		struct eth_pdata *pdata = dev->platdata;
495 
496 		dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
497 		dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
498 		dp->dp.length = sizeof(*dp);
499 		memset(&dp->mac, 0, sizeof(dp->mac));
500 		/* We only support IPv4 */
501 		memcpy(&dp->mac, &pdata->enetaddr, ARP_HLEN);
502 		/* Ethernet */
503 		dp->if_type = 1;
504 		return &dp[1];
505 	}
506 #endif
507 #ifdef CONFIG_BLK
508 	case UCLASS_BLK:
509 		switch (dev->parent->uclass->uc_drv->id) {
510 #ifdef CONFIG_IDE
511 		case UCLASS_IDE: {
512 			struct efi_device_path_atapi *dp =
513 			dp_fill(buf, dev->parent);
514 			struct blk_desc *desc = dev_get_uclass_platdata(dev);
515 
516 			dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
517 			dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_ATAPI;
518 			dp->dp.length = sizeof(*dp);
519 			dp->logical_unit_number = desc->devnum;
520 			dp->primary_secondary = IDE_BUS(desc->devnum);
521 			dp->slave_master = desc->devnum %
522 				(CONFIG_SYS_IDE_MAXDEVICE /
523 				 CONFIG_SYS_IDE_MAXBUS);
524 			return &dp[1];
525 			}
526 #endif
527 #if defined(CONFIG_SCSI) && defined(CONFIG_DM_SCSI)
528 		case UCLASS_SCSI: {
529 			struct efi_device_path_scsi *dp =
530 				dp_fill(buf, dev->parent);
531 			struct blk_desc *desc = dev_get_uclass_platdata(dev);
532 
533 			dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
534 			dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_SCSI;
535 			dp->dp.length = sizeof(*dp);
536 			dp->logical_unit_number = desc->lun;
537 			dp->target_id = desc->target;
538 			return &dp[1];
539 			}
540 #endif
541 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
542 		case UCLASS_MMC: {
543 			struct efi_device_path_sd_mmc_path *sddp =
544 				dp_fill(buf, dev->parent);
545 			struct blk_desc *desc = dev_get_uclass_platdata(dev);
546 
547 			sddp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
548 			sddp->dp.sub_type = is_sd(desc) ?
549 				DEVICE_PATH_SUB_TYPE_MSG_SD :
550 				DEVICE_PATH_SUB_TYPE_MSG_MMC;
551 			sddp->dp.length   = sizeof(*sddp);
552 			sddp->slot_number = dev->seq;
553 			return &sddp[1];
554 			}
555 #endif
556 		default:
557 			debug("%s(%u) %s: unhandled parent class: %s (%u)\n",
558 			      __FILE__, __LINE__, __func__,
559 			      dev->name, dev->parent->uclass->uc_drv->id);
560 			return dp_fill(buf, dev->parent);
561 		}
562 #endif
563 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
564 	case UCLASS_MMC: {
565 		struct efi_device_path_sd_mmc_path *sddp =
566 			dp_fill(buf, dev->parent);
567 		struct mmc *mmc = mmc_get_mmc_dev(dev);
568 		struct blk_desc *desc = mmc_get_blk_desc(mmc);
569 
570 		sddp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
571 		sddp->dp.sub_type = is_sd(desc) ?
572 			DEVICE_PATH_SUB_TYPE_MSG_SD :
573 			DEVICE_PATH_SUB_TYPE_MSG_MMC;
574 		sddp->dp.length   = sizeof(*sddp);
575 		sddp->slot_number = dev->seq;
576 
577 		return &sddp[1];
578 	}
579 #endif
580 	case UCLASS_MASS_STORAGE:
581 	case UCLASS_USB_HUB: {
582 		struct efi_device_path_usb_class *udp =
583 			dp_fill(buf, dev->parent);
584 		struct usb_device *udev = dev_get_parent_priv(dev);
585 		struct usb_device_descriptor *desc = &udev->descriptor;
586 
587 		udp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
588 		udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS;
589 		udp->dp.length   = sizeof(*udp);
590 		udp->vendor_id   = desc->idVendor;
591 		udp->product_id  = desc->idProduct;
592 		udp->device_class    = desc->bDeviceClass;
593 		udp->device_subclass = desc->bDeviceSubClass;
594 		udp->device_protocol = desc->bDeviceProtocol;
595 
596 		return &udp[1];
597 	}
598 	default:
599 		debug("%s(%u) %s: unhandled device class: %s (%u)\n",
600 		      __FILE__, __LINE__, __func__,
601 		      dev->name, dev->driver->id);
602 		return dp_fill(buf, dev->parent);
603 	}
604 }
605 
606 /* Construct a device-path from a device: */
607 struct efi_device_path *efi_dp_from_dev(struct udevice *dev)
608 {
609 	void *buf, *start;
610 
611 	start = buf = dp_alloc(dp_size(dev) + sizeof(END));
612 	if (!buf)
613 		return NULL;
614 	buf = dp_fill(buf, dev);
615 	*((struct efi_device_path *)buf) = END;
616 
617 	return start;
618 }
619 #endif
620 
621 static unsigned dp_part_size(struct blk_desc *desc, int part)
622 {
623 	unsigned dpsize;
624 
625 #ifdef CONFIG_BLK
626 	{
627 		struct udevice *dev;
628 		int ret = blk_find_device(desc->if_type, desc->devnum, &dev);
629 
630 		if (ret)
631 			dev = desc->bdev->parent;
632 		dpsize = dp_size(dev);
633 	}
634 #else
635 	dpsize = sizeof(ROOT) + sizeof(struct efi_device_path_usb);
636 #endif
637 
638 	if (part == 0) /* the actual disk, not a partition */
639 		return dpsize;
640 
641 	if (desc->part_type == PART_TYPE_ISO)
642 		dpsize += sizeof(struct efi_device_path_cdrom_path);
643 	else
644 		dpsize += sizeof(struct efi_device_path_hard_drive_path);
645 
646 	return dpsize;
647 }
648 
649 /*
650  * Create a device node for a block device partition.
651  *
652  * @buf		buffer to which the device path is wirtten
653  * @desc	block device descriptor
654  * @part	partition number, 0 identifies a block device
655  */
656 static void *dp_part_node(void *buf, struct blk_desc *desc, int part)
657 {
658 	disk_partition_t info;
659 
660 	part_get_info(desc, part, &info);
661 
662 	if (desc->part_type == PART_TYPE_ISO) {
663 		struct efi_device_path_cdrom_path *cddp = buf;
664 
665 		cddp->boot_entry = part;
666 		cddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
667 		cddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_CDROM_PATH;
668 		cddp->dp.length = sizeof(*cddp);
669 		cddp->partition_start = info.start;
670 		cddp->partition_end = info.size;
671 
672 		buf = &cddp[1];
673 	} else {
674 		struct efi_device_path_hard_drive_path *hddp = buf;
675 
676 		hddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
677 		hddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH;
678 		hddp->dp.length = sizeof(*hddp);
679 		hddp->partition_number = part;
680 		hddp->partition_start = info.start;
681 		hddp->partition_end = info.size;
682 		if (desc->part_type == PART_TYPE_EFI)
683 			hddp->partmap_type = 2;
684 		else
685 			hddp->partmap_type = 1;
686 
687 		switch (desc->sig_type) {
688 		case SIG_TYPE_NONE:
689 		default:
690 			hddp->signature_type = 0;
691 			memset(hddp->partition_signature, 0,
692 			       sizeof(hddp->partition_signature));
693 			break;
694 		case SIG_TYPE_MBR:
695 			hddp->signature_type = 1;
696 			memset(hddp->partition_signature, 0,
697 			       sizeof(hddp->partition_signature));
698 			memcpy(hddp->partition_signature, &desc->mbr_sig,
699 			       sizeof(desc->mbr_sig));
700 			break;
701 		case SIG_TYPE_GUID:
702 			hddp->signature_type = 2;
703 			memcpy(hddp->partition_signature, &desc->guid_sig,
704 			       sizeof(hddp->partition_signature));
705 			break;
706 		}
707 
708 		buf = &hddp[1];
709 	}
710 
711 	return buf;
712 }
713 
714 /*
715  * Create a device path for a block device or one of its partitions.
716  *
717  * @buf		buffer to which the device path is wirtten
718  * @desc	block device descriptor
719  * @part	partition number, 0 identifies a block device
720  */
721 static void *dp_part_fill(void *buf, struct blk_desc *desc, int part)
722 {
723 #ifdef CONFIG_BLK
724 	{
725 		struct udevice *dev;
726 		int ret = blk_find_device(desc->if_type, desc->devnum, &dev);
727 
728 		if (ret)
729 			dev = desc->bdev->parent;
730 		buf = dp_fill(buf, dev);
731 	}
732 #else
733 	/*
734 	 * We *could* make a more accurate path, by looking at if_type
735 	 * and handling all the different cases like we do for non-
736 	 * legacy (ie CONFIG_BLK=y) case.  But most important thing
737 	 * is just to have a unique device-path for if_type+devnum.
738 	 * So map things to a fictitious USB device.
739 	 */
740 	struct efi_device_path_usb *udp;
741 
742 	memcpy(buf, &ROOT, sizeof(ROOT));
743 	buf += sizeof(ROOT);
744 
745 	udp = buf;
746 	udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
747 	udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB;
748 	udp->dp.length = sizeof(*udp);
749 	udp->parent_port_number = desc->if_type;
750 	udp->usb_interface = desc->devnum;
751 	buf = &udp[1];
752 #endif
753 
754 	if (part == 0) /* the actual disk, not a partition */
755 		return buf;
756 
757 	return dp_part_node(buf, desc, part);
758 }
759 
760 /* Construct a device-path from a partition on a blk device: */
761 struct efi_device_path *efi_dp_from_part(struct blk_desc *desc, int part)
762 {
763 	void *buf, *start;
764 
765 	start = buf = dp_alloc(dp_part_size(desc, part) + sizeof(END));
766 	if (!buf)
767 		return NULL;
768 
769 	buf = dp_part_fill(buf, desc, part);
770 
771 	*((struct efi_device_path *)buf) = END;
772 
773 	return start;
774 }
775 
776 /*
777  * Create a device node for a block device partition.
778  *
779  * @buf		buffer to which the device path is wirtten
780  * @desc	block device descriptor
781  * @part	partition number, 0 identifies a block device
782  */
783 struct efi_device_path *efi_dp_part_node(struct blk_desc *desc, int part)
784 {
785 	efi_uintn_t dpsize;
786 	void *buf;
787 
788 	if (desc->part_type == PART_TYPE_ISO)
789 		dpsize = sizeof(struct efi_device_path_cdrom_path);
790 	else
791 		dpsize = sizeof(struct efi_device_path_hard_drive_path);
792 	buf = dp_alloc(dpsize);
793 
794 	dp_part_node(buf, desc, part);
795 
796 	return buf;
797 }
798 
799 /* convert path to an UEFI style path (ie. DOS style backslashes and utf16) */
800 static void path_to_uefi(u16 *uefi, const char *path)
801 {
802 	while (*path) {
803 		char c = *(path++);
804 		if (c == '/')
805 			c = '\\';
806 		*(uefi++) = c;
807 	}
808 	*uefi = '\0';
809 }
810 
811 /*
812  * If desc is NULL, this creates a path with only the file component,
813  * otherwise it creates a full path with both device and file components
814  */
815 struct efi_device_path *efi_dp_from_file(struct blk_desc *desc, int part,
816 		const char *path)
817 {
818 	struct efi_device_path_file_path *fp;
819 	void *buf, *start;
820 	unsigned dpsize = 0, fpsize;
821 
822 	if (desc)
823 		dpsize = dp_part_size(desc, part);
824 
825 	fpsize = sizeof(struct efi_device_path) + 2 * (strlen(path) + 1);
826 	dpsize += fpsize;
827 
828 	start = buf = dp_alloc(dpsize + sizeof(END));
829 	if (!buf)
830 		return NULL;
831 
832 	if (desc)
833 		buf = dp_part_fill(buf, desc, part);
834 
835 	/* add file-path: */
836 	fp = buf;
837 	fp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
838 	fp->dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
839 	fp->dp.length = fpsize;
840 	path_to_uefi(fp->str, path);
841 	buf += fpsize;
842 
843 	*((struct efi_device_path *)buf) = END;
844 
845 	return start;
846 }
847 
848 #ifdef CONFIG_NET
849 struct efi_device_path *efi_dp_from_eth(void)
850 {
851 #ifndef CONFIG_DM_ETH
852 	struct efi_device_path_mac_addr *ndp;
853 #endif
854 	void *buf, *start;
855 	unsigned dpsize = 0;
856 
857 	assert(eth_get_dev());
858 
859 #ifdef CONFIG_DM_ETH
860 	dpsize += dp_size(eth_get_dev());
861 #else
862 	dpsize += sizeof(ROOT);
863 	dpsize += sizeof(*ndp);
864 #endif
865 
866 	start = buf = dp_alloc(dpsize + sizeof(END));
867 	if (!buf)
868 		return NULL;
869 
870 #ifdef CONFIG_DM_ETH
871 	buf = dp_fill(buf, eth_get_dev());
872 #else
873 	memcpy(buf, &ROOT, sizeof(ROOT));
874 	buf += sizeof(ROOT);
875 
876 	ndp = buf;
877 	ndp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
878 	ndp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
879 	ndp->dp.length = sizeof(*ndp);
880 	ndp->if_type = 1; /* Ethernet */
881 	memcpy(ndp->mac.addr, eth_get_ethaddr(), ARP_HLEN);
882 	buf = &ndp[1];
883 #endif
884 
885 	*((struct efi_device_path *)buf) = END;
886 
887 	return start;
888 }
889 #endif
890 
891 /* Construct a device-path for memory-mapped image */
892 struct efi_device_path *efi_dp_from_mem(uint32_t memory_type,
893 					uint64_t start_address,
894 					uint64_t end_address)
895 {
896 	struct efi_device_path_memory *mdp;
897 	void *buf, *start;
898 
899 	start = buf = dp_alloc(sizeof(*mdp) + sizeof(END));
900 	if (!buf)
901 		return NULL;
902 
903 	mdp = buf;
904 	mdp->dp.type = DEVICE_PATH_TYPE_HARDWARE_DEVICE;
905 	mdp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MEMORY;
906 	mdp->dp.length = sizeof(*mdp);
907 	mdp->memory_type = memory_type;
908 	mdp->start_address = start_address;
909 	mdp->end_address = end_address;
910 	buf = &mdp[1];
911 
912 	*((struct efi_device_path *)buf) = END;
913 
914 	return start;
915 }
916 
917 /*
918  * Helper to split a full device path (containing both device and file
919  * parts) into it's constituent parts.
920  */
921 efi_status_t efi_dp_split_file_path(struct efi_device_path *full_path,
922 				    struct efi_device_path **device_path,
923 				    struct efi_device_path **file_path)
924 {
925 	struct efi_device_path *p, *dp, *fp;
926 
927 	*device_path = NULL;
928 	*file_path = NULL;
929 	dp = efi_dp_dup(full_path);
930 	if (!dp)
931 		return EFI_OUT_OF_RESOURCES;
932 	p = dp;
933 	while (!EFI_DP_TYPE(p, MEDIA_DEVICE, FILE_PATH)) {
934 		p = efi_dp_next(p);
935 		if (!p)
936 			return EFI_OUT_OF_RESOURCES;
937 	}
938 	fp = efi_dp_dup(p);
939 	if (!fp)
940 		return EFI_OUT_OF_RESOURCES;
941 	p->type = DEVICE_PATH_TYPE_END;
942 	p->sub_type = DEVICE_PATH_SUB_TYPE_END;
943 	p->length = sizeof(*p);
944 
945 	*device_path = dp;
946 	*file_path = fp;
947 	return EFI_SUCCESS;
948 }
949