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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 <inttypes.h>
17 #include <part.h>
18 
19 /* template END node: */
20 static const struct efi_device_path END = {
21 	.type     = DEVICE_PATH_TYPE_END,
22 	.sub_type = DEVICE_PATH_SUB_TYPE_END,
23 	.length   = sizeof(END),
24 };
25 
26 #define U_BOOT_GUID \
27 	EFI_GUID(0xe61d73b9, 0xa384, 0x4acc, \
28 		 0xae, 0xab, 0x82, 0xe8, 0x28, 0xf3, 0x62, 0x8b)
29 
30 /* template ROOT node: */
31 static const struct efi_device_path_vendor ROOT = {
32 	.dp = {
33 		.type     = DEVICE_PATH_TYPE_HARDWARE_DEVICE,
34 		.sub_type = DEVICE_PATH_SUB_TYPE_VENDOR,
35 		.length   = sizeof(ROOT),
36 	},
37 	.guid = U_BOOT_GUID,
38 };
39 
40 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
41 /*
42  * Determine if an MMC device is an SD card.
43  *
44  * @desc	block device descriptor
45  * @return	true if the device is an SD card
46  */
is_sd(struct blk_desc * desc)47 static bool is_sd(struct blk_desc *desc)
48 {
49 	struct mmc *mmc = find_mmc_device(desc->devnum);
50 
51 	if (!mmc)
52 		return false;
53 
54 	return IS_SD(mmc) != 0U;
55 }
56 #endif
57 
dp_alloc(size_t sz)58 static void *dp_alloc(size_t sz)
59 {
60 	void *buf;
61 
62 	if (efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, sz, &buf) !=
63 	    EFI_SUCCESS) {
64 		debug("EFI: ERROR: out of memory in %s\n", __func__);
65 		return NULL;
66 	}
67 
68 	memset(buf, 0, sz);
69 	return buf;
70 }
71 
72 /*
73  * Iterate to next block in device-path, terminating (returning NULL)
74  * at /End* node.
75  */
efi_dp_next(const struct efi_device_path * dp)76 struct efi_device_path *efi_dp_next(const struct efi_device_path *dp)
77 {
78 	if (dp == NULL)
79 		return NULL;
80 	if (dp->type == DEVICE_PATH_TYPE_END)
81 		return NULL;
82 	dp = ((void *)dp) + dp->length;
83 	if (dp->type == DEVICE_PATH_TYPE_END)
84 		return NULL;
85 	return (struct efi_device_path *)dp;
86 }
87 
88 /*
89  * Compare two device-paths, stopping when the shorter of the two hits
90  * an End* node.  This is useful to, for example, compare a device-path
91  * representing a device with one representing a file on the device, or
92  * a device with a parent device.
93  */
efi_dp_match(const struct efi_device_path * a,const struct efi_device_path * b)94 int efi_dp_match(const struct efi_device_path *a,
95 		 const struct efi_device_path *b)
96 {
97 	while (1) {
98 		int ret;
99 
100 		ret = memcmp(&a->length, &b->length, sizeof(a->length));
101 		if (ret)
102 			return ret;
103 
104 		ret = memcmp(a, b, a->length);
105 		if (ret)
106 			return ret;
107 
108 		a = efi_dp_next(a);
109 		b = efi_dp_next(b);
110 
111 		if (!a || !b)
112 			return 0;
113 	}
114 }
115 
116 /*
117  * See UEFI spec (section 3.1.2, about short-form device-paths..
118  * tl;dr: we can have a device-path that starts with a USB WWID
119  * or USB Class node, and a few other cases which don't encode
120  * the full device path with bus hierarchy:
121  *
122  *   - MESSAGING:USB_WWID
123  *   - MESSAGING:USB_CLASS
124  *   - MEDIA:FILE_PATH
125  *   - MEDIA:HARD_DRIVE
126  *   - MESSAGING:URI
127  */
shorten_path(struct efi_device_path * dp)128 static struct efi_device_path *shorten_path(struct efi_device_path *dp)
129 {
130 	while (dp) {
131 		/*
132 		 * TODO: Add MESSAGING:USB_WWID and MESSAGING:URI..
133 		 * in practice fallback.efi just uses MEDIA:HARD_DRIVE
134 		 * so not sure when we would see these other cases.
135 		 */
136 		if (EFI_DP_TYPE(dp, MESSAGING_DEVICE, MSG_USB_CLASS) ||
137 		    EFI_DP_TYPE(dp, MEDIA_DEVICE, HARD_DRIVE_PATH) ||
138 		    EFI_DP_TYPE(dp, MEDIA_DEVICE, FILE_PATH))
139 			return dp;
140 
141 		dp = efi_dp_next(dp);
142 	}
143 
144 	return dp;
145 }
146 
find_obj(struct efi_device_path * dp,bool short_path,struct efi_device_path ** rem)147 static struct efi_object *find_obj(struct efi_device_path *dp, bool short_path,
148 				   struct efi_device_path **rem)
149 {
150 	struct efi_object *efiobj;
151 	efi_uintn_t dp_size = efi_dp_instance_size(dp);
152 
153 	list_for_each_entry(efiobj, &efi_obj_list, link) {
154 		struct efi_handler *handler;
155 		struct efi_device_path *obj_dp;
156 		efi_status_t ret;
157 
158 		ret = efi_search_protocol(efiobj->handle,
159 					  &efi_guid_device_path, &handler);
160 		if (ret != EFI_SUCCESS)
161 			continue;
162 		obj_dp = handler->protocol_interface;
163 
164 		do {
165 			if (efi_dp_match(dp, obj_dp) == 0) {
166 				if (rem) {
167 					/*
168 					 * Allow partial matches, but inform
169 					 * the caller.
170 					 */
171 					*rem = ((void *)dp) +
172 						efi_dp_instance_size(obj_dp);
173 					return efiobj;
174 				} else {
175 					/* Only return on exact matches */
176 					if (efi_dp_instance_size(obj_dp) ==
177 					    dp_size)
178 						return efiobj;
179 				}
180 			}
181 
182 			obj_dp = shorten_path(efi_dp_next(obj_dp));
183 		} while (short_path && obj_dp);
184 	}
185 
186 	return NULL;
187 }
188 
189 /*
190  * Find an efiobj from device-path, if 'rem' is not NULL, returns the
191  * remaining part of the device path after the matched object.
192  */
efi_dp_find_obj(struct efi_device_path * dp,struct efi_device_path ** rem)193 struct efi_object *efi_dp_find_obj(struct efi_device_path *dp,
194 				   struct efi_device_path **rem)
195 {
196 	struct efi_object *efiobj;
197 
198 	/* Search for an exact match first */
199 	efiobj = find_obj(dp, false, NULL);
200 
201 	/* Then for a fuzzy match */
202 	if (!efiobj)
203 		efiobj = find_obj(dp, false, rem);
204 
205 	/* And now for a fuzzy short match */
206 	if (!efiobj)
207 		efiobj = find_obj(dp, true, rem);
208 
209 	return efiobj;
210 }
211 
212 /*
213  * Determine the last device path node that is not the end node.
214  *
215  * @dp		device path
216  * @return	last node before the end node if it exists
217  *		otherwise NULL
218  */
efi_dp_last_node(const struct efi_device_path * dp)219 const struct efi_device_path *efi_dp_last_node(const struct efi_device_path *dp)
220 {
221 	struct efi_device_path *ret;
222 
223 	if (!dp || dp->type == DEVICE_PATH_TYPE_END)
224 		return NULL;
225 	while (dp) {
226 		ret = (struct efi_device_path *)dp;
227 		dp = efi_dp_next(dp);
228 	}
229 	return ret;
230 }
231 
232 /* get size of the first device path instance excluding end node */
efi_dp_instance_size(const struct efi_device_path * dp)233 efi_uintn_t efi_dp_instance_size(const struct efi_device_path *dp)
234 {
235 	efi_uintn_t sz = 0;
236 
237 	if (!dp || dp->type == DEVICE_PATH_TYPE_END)
238 		return 0;
239 	while (dp) {
240 		sz += dp->length;
241 		dp = efi_dp_next(dp);
242 	}
243 
244 	return sz;
245 }
246 
247 /* get size of multi-instance device path excluding end node */
efi_dp_size(const struct efi_device_path * dp)248 efi_uintn_t efi_dp_size(const struct efi_device_path *dp)
249 {
250 	const struct efi_device_path *p = dp;
251 
252 	if (!p)
253 		return 0;
254 	while (p->type != DEVICE_PATH_TYPE_END ||
255 	       p->sub_type != DEVICE_PATH_SUB_TYPE_END)
256 		p = (void *)p + p->length;
257 
258 	return (void *)p - (void *)dp;
259 }
260 
261 /* copy multi-instance device path */
efi_dp_dup(const struct efi_device_path * dp)262 struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp)
263 {
264 	struct efi_device_path *ndp;
265 	size_t sz = efi_dp_size(dp) + sizeof(END);
266 
267 	if (!dp)
268 		return NULL;
269 
270 	ndp = dp_alloc(sz);
271 	if (!ndp)
272 		return NULL;
273 	memcpy(ndp, dp, sz);
274 
275 	return ndp;
276 }
277 
efi_dp_append(const struct efi_device_path * dp1,const struct efi_device_path * dp2)278 struct efi_device_path *efi_dp_append(const struct efi_device_path *dp1,
279 				      const struct efi_device_path *dp2)
280 {
281 	struct efi_device_path *ret;
282 
283 	if (!dp1 && !dp2) {
284 		/* return an end node */
285 		ret = efi_dp_dup(&END);
286 	} else if (!dp1) {
287 		ret = efi_dp_dup(dp2);
288 	} else if (!dp2) {
289 		ret = efi_dp_dup(dp1);
290 	} else {
291 		/* both dp1 and dp2 are non-null */
292 		unsigned sz1 = efi_dp_size(dp1);
293 		unsigned sz2 = efi_dp_size(dp2);
294 		void *p = dp_alloc(sz1 + sz2 + sizeof(END));
295 		if (!p)
296 			return NULL;
297 		memcpy(p, dp1, sz1);
298 		/* the end node of the second device path has to be retained */
299 		memcpy(p + sz1, dp2, sz2 + sizeof(END));
300 		ret = p;
301 	}
302 
303 	return ret;
304 }
305 
efi_dp_append_node(const struct efi_device_path * dp,const struct efi_device_path * node)306 struct efi_device_path *efi_dp_append_node(const struct efi_device_path *dp,
307 					   const struct efi_device_path *node)
308 {
309 	struct efi_device_path *ret;
310 
311 	if (!node && !dp) {
312 		ret = efi_dp_dup(&END);
313 	} else if (!node) {
314 		ret = efi_dp_dup(dp);
315 	} else if (!dp) {
316 		size_t sz = node->length;
317 		void *p = dp_alloc(sz + sizeof(END));
318 		if (!p)
319 			return NULL;
320 		memcpy(p, node, sz);
321 		memcpy(p + sz, &END, sizeof(END));
322 		ret = p;
323 	} else {
324 		/* both dp and node are non-null */
325 		size_t sz = efi_dp_size(dp);
326 		void *p = dp_alloc(sz + node->length + sizeof(END));
327 		if (!p)
328 			return NULL;
329 		memcpy(p, dp, sz);
330 		memcpy(p + sz, node, node->length);
331 		memcpy(p + sz + node->length, &END, sizeof(END));
332 		ret = p;
333 	}
334 
335 	return ret;
336 }
337 
efi_dp_create_device_node(const u8 type,const u8 sub_type,const u16 length)338 struct efi_device_path *efi_dp_create_device_node(const u8 type,
339 						  const u8 sub_type,
340 						  const u16 length)
341 {
342 	struct efi_device_path *ret;
343 
344 	ret = dp_alloc(length);
345 	if (!ret)
346 		return ret;
347 	ret->type = type;
348 	ret->sub_type = sub_type;
349 	ret->length = length;
350 	return ret;
351 }
352 
efi_dp_append_instance(const struct efi_device_path * dp,const struct efi_device_path * dpi)353 struct efi_device_path *efi_dp_append_instance(
354 		const struct efi_device_path *dp,
355 		const struct efi_device_path *dpi)
356 {
357 	size_t sz, szi;
358 	struct efi_device_path *p, *ret;
359 
360 	if (!dpi)
361 		return NULL;
362 	if (!dp)
363 		return efi_dp_dup(dpi);
364 	sz = efi_dp_size(dp);
365 	szi = efi_dp_instance_size(dpi);
366 	p = dp_alloc(sz + szi + 2 * sizeof(END));
367 	if (!p)
368 		return NULL;
369 	ret = p;
370 	memcpy(p, dp, sz + sizeof(END));
371 	p = (void *)p + sz;
372 	p->sub_type = DEVICE_PATH_SUB_TYPE_INSTANCE_END;
373 	p = (void *)p + sizeof(END);
374 	memcpy(p, dpi, szi);
375 	p = (void *)p + szi;
376 	memcpy(p, &END, sizeof(END));
377 	return ret;
378 }
379 
efi_dp_get_next_instance(struct efi_device_path ** dp,efi_uintn_t * size)380 struct efi_device_path *efi_dp_get_next_instance(struct efi_device_path **dp,
381 						 efi_uintn_t *size)
382 {
383 	size_t sz;
384 	struct efi_device_path *p;
385 
386 	if (size)
387 		*size = 0;
388 	if (!dp || !*dp)
389 		return NULL;
390 	p = *dp;
391 	sz = efi_dp_instance_size(*dp);
392 	p = dp_alloc(sz + sizeof(END));
393 	if (!p)
394 		return NULL;
395 	memcpy(p, *dp, sz + sizeof(END));
396 	*dp = (void *)*dp + sz;
397 	if ((*dp)->sub_type == DEVICE_PATH_SUB_TYPE_INSTANCE_END)
398 		*dp = (void *)*dp + sizeof(END);
399 	else
400 		*dp = NULL;
401 	if (size)
402 		*size = sz + sizeof(END);
403 	return p;
404 }
405 
efi_dp_is_multi_instance(const struct efi_device_path * dp)406 bool efi_dp_is_multi_instance(const struct efi_device_path *dp)
407 {
408 	const struct efi_device_path *p = dp;
409 
410 	if (!p)
411 		return false;
412 	while (p->type != DEVICE_PATH_TYPE_END)
413 		p = (void *)p + p->length;
414 	return p->sub_type == DEVICE_PATH_SUB_TYPE_INSTANCE_END;
415 }
416 
417 #ifdef CONFIG_DM
418 /* size of device-path not including END node for device and all parents
419  * up to the root device.
420  */
dp_size(struct udevice * dev)421 static unsigned dp_size(struct udevice *dev)
422 {
423 	if (!dev || !dev->driver)
424 		return sizeof(ROOT);
425 
426 	switch (dev->driver->id) {
427 	case UCLASS_ROOT:
428 	case UCLASS_SIMPLE_BUS:
429 		/* stop traversing parents at this point: */
430 		return sizeof(ROOT);
431 	case UCLASS_ETH:
432 		return dp_size(dev->parent) +
433 			sizeof(struct efi_device_path_mac_addr);
434 #ifdef CONFIG_BLK
435 	case UCLASS_BLK:
436 		switch (dev->parent->uclass->uc_drv->id) {
437 #ifdef CONFIG_IDE
438 		case UCLASS_IDE:
439 			return dp_size(dev->parent) +
440 				sizeof(struct efi_device_path_atapi);
441 #endif
442 #if defined(CONFIG_SCSI) && defined(CONFIG_DM_SCSI)
443 		case UCLASS_SCSI:
444 			return dp_size(dev->parent) +
445 				sizeof(struct efi_device_path_scsi);
446 #endif
447 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
448 		case UCLASS_MMC:
449 			return dp_size(dev->parent) +
450 				sizeof(struct efi_device_path_sd_mmc_path);
451 #endif
452 		default:
453 			return dp_size(dev->parent);
454 		}
455 #endif
456 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
457 	case UCLASS_MMC:
458 		return dp_size(dev->parent) +
459 			sizeof(struct efi_device_path_sd_mmc_path);
460 #endif
461 	case UCLASS_MASS_STORAGE:
462 	case UCLASS_USB_HUB:
463 		return dp_size(dev->parent) +
464 			sizeof(struct efi_device_path_usb_class);
465 	default:
466 		/* just skip over unknown classes: */
467 		return dp_size(dev->parent);
468 	}
469 }
470 
471 /*
472  * Recursively build a device path.
473  *
474  * @buf		pointer to the end of the device path
475  * @dev		device
476  * @return	pointer to the end of the device path
477  */
dp_fill(void * buf,struct udevice * dev)478 static void *dp_fill(void *buf, struct udevice *dev)
479 {
480 	if (!dev || !dev->driver)
481 		return buf;
482 
483 	switch (dev->driver->id) {
484 	case UCLASS_ROOT:
485 	case UCLASS_SIMPLE_BUS: {
486 		/* stop traversing parents at this point: */
487 		struct efi_device_path_vendor *vdp = buf;
488 		*vdp = ROOT;
489 		return &vdp[1];
490 	}
491 #ifdef CONFIG_DM_ETH
492 	case UCLASS_ETH: {
493 		struct efi_device_path_mac_addr *dp =
494 			dp_fill(buf, dev->parent);
495 		struct eth_pdata *pdata = dev->platdata;
496 
497 		dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
498 		dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
499 		dp->dp.length = sizeof(*dp);
500 		memset(&dp->mac, 0, sizeof(dp->mac));
501 		/* We only support IPv4 */
502 		memcpy(&dp->mac, &pdata->enetaddr, ARP_HLEN);
503 		/* Ethernet */
504 		dp->if_type = 1;
505 		return &dp[1];
506 	}
507 #endif
508 #ifdef CONFIG_BLK
509 	case UCLASS_BLK:
510 		switch (dev->parent->uclass->uc_drv->id) {
511 #ifdef CONFIG_IDE
512 		case UCLASS_IDE: {
513 			struct efi_device_path_atapi *dp =
514 			dp_fill(buf, dev->parent);
515 			struct blk_desc *desc = dev_get_uclass_platdata(dev);
516 
517 			dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
518 			dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_ATAPI;
519 			dp->dp.length = sizeof(*dp);
520 			dp->logical_unit_number = desc->devnum;
521 			dp->primary_secondary = IDE_BUS(desc->devnum);
522 			dp->slave_master = desc->devnum %
523 				(CONFIG_SYS_IDE_MAXDEVICE /
524 				 CONFIG_SYS_IDE_MAXBUS);
525 			return &dp[1];
526 			}
527 #endif
528 #if defined(CONFIG_SCSI) && defined(CONFIG_DM_SCSI)
529 		case UCLASS_SCSI: {
530 			struct efi_device_path_scsi *dp =
531 				dp_fill(buf, dev->parent);
532 			struct blk_desc *desc = dev_get_uclass_platdata(dev);
533 
534 			dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
535 			dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_SCSI;
536 			dp->dp.length = sizeof(*dp);
537 			dp->logical_unit_number = desc->lun;
538 			dp->target_id = desc->target;
539 			return &dp[1];
540 			}
541 #endif
542 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
543 		case UCLASS_MMC: {
544 			struct efi_device_path_sd_mmc_path *sddp =
545 				dp_fill(buf, dev->parent);
546 			struct blk_desc *desc = dev_get_uclass_platdata(dev);
547 
548 			sddp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
549 			sddp->dp.sub_type = is_sd(desc) ?
550 				DEVICE_PATH_SUB_TYPE_MSG_SD :
551 				DEVICE_PATH_SUB_TYPE_MSG_MMC;
552 			sddp->dp.length   = sizeof(*sddp);
553 			sddp->slot_number = dev->seq;
554 			return &sddp[1];
555 			}
556 #endif
557 		default:
558 			debug("%s(%u) %s: unhandled parent class: %s (%u)\n",
559 			      __FILE__, __LINE__, __func__,
560 			      dev->name, dev->parent->uclass->uc_drv->id);
561 			return dp_fill(buf, dev->parent);
562 		}
563 #endif
564 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
565 	case UCLASS_MMC: {
566 		struct efi_device_path_sd_mmc_path *sddp =
567 			dp_fill(buf, dev->parent);
568 		struct mmc *mmc = mmc_get_mmc_dev(dev);
569 		struct blk_desc *desc = mmc_get_blk_desc(mmc);
570 
571 		sddp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
572 		sddp->dp.sub_type = is_sd(desc) ?
573 			DEVICE_PATH_SUB_TYPE_MSG_SD :
574 			DEVICE_PATH_SUB_TYPE_MSG_MMC;
575 		sddp->dp.length   = sizeof(*sddp);
576 		sddp->slot_number = dev->seq;
577 
578 		return &sddp[1];
579 	}
580 #endif
581 	case UCLASS_MASS_STORAGE:
582 	case UCLASS_USB_HUB: {
583 		struct efi_device_path_usb_class *udp =
584 			dp_fill(buf, dev->parent);
585 		struct usb_device *udev = dev_get_parent_priv(dev);
586 		struct usb_device_descriptor *desc = &udev->descriptor;
587 
588 		udp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
589 		udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS;
590 		udp->dp.length   = sizeof(*udp);
591 		udp->vendor_id   = desc->idVendor;
592 		udp->product_id  = desc->idProduct;
593 		udp->device_class    = desc->bDeviceClass;
594 		udp->device_subclass = desc->bDeviceSubClass;
595 		udp->device_protocol = desc->bDeviceProtocol;
596 
597 		return &udp[1];
598 	}
599 	default:
600 		debug("%s(%u) %s: unhandled device class: %s (%u)\n",
601 		      __FILE__, __LINE__, __func__,
602 		      dev->name, dev->driver->id);
603 		return dp_fill(buf, dev->parent);
604 	}
605 }
606 
607 /* Construct a device-path from a device: */
efi_dp_from_dev(struct udevice * dev)608 struct efi_device_path *efi_dp_from_dev(struct udevice *dev)
609 {
610 	void *buf, *start;
611 
612 	start = buf = dp_alloc(dp_size(dev) + sizeof(END));
613 	if (!buf)
614 		return NULL;
615 	buf = dp_fill(buf, dev);
616 	*((struct efi_device_path *)buf) = END;
617 
618 	return start;
619 }
620 #endif
621 
dp_part_size(struct blk_desc * desc,int part)622 static unsigned dp_part_size(struct blk_desc *desc, int part)
623 {
624 	unsigned dpsize;
625 
626 #ifdef CONFIG_BLK
627 	{
628 		struct udevice *dev;
629 		int ret = blk_find_device(desc->if_type, desc->devnum, &dev);
630 
631 		if (ret)
632 			dev = desc->bdev->parent;
633 		dpsize = dp_size(dev);
634 	}
635 #else
636 	dpsize = sizeof(ROOT) + sizeof(struct efi_device_path_usb);
637 #endif
638 
639 	if (part == 0) /* the actual disk, not a partition */
640 		return dpsize;
641 
642 	if (desc->part_type == PART_TYPE_ISO)
643 		dpsize += sizeof(struct efi_device_path_cdrom_path);
644 	else
645 		dpsize += sizeof(struct efi_device_path_hard_drive_path);
646 
647 	return dpsize;
648 }
649 
650 /*
651  * Create a device node for a block device partition.
652  *
653  * @buf		buffer to which the device path is wirtten
654  * @desc	block device descriptor
655  * @part	partition number, 0 identifies a block device
656  */
dp_part_node(void * buf,struct blk_desc * desc,int part)657 static void *dp_part_node(void *buf, struct blk_desc *desc, int part)
658 {
659 	disk_partition_t info;
660 
661 	part_get_info(desc, part, &info);
662 
663 	if (desc->part_type == PART_TYPE_ISO) {
664 		struct efi_device_path_cdrom_path *cddp = buf;
665 
666 		cddp->boot_entry = part;
667 		cddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
668 		cddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_CDROM_PATH;
669 		cddp->dp.length = sizeof(*cddp);
670 		cddp->partition_start = info.start;
671 		cddp->partition_end = info.size;
672 
673 		buf = &cddp[1];
674 	} else {
675 		struct efi_device_path_hard_drive_path *hddp = buf;
676 
677 		hddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
678 		hddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH;
679 		hddp->dp.length = sizeof(*hddp);
680 		hddp->partition_number = part;
681 		hddp->partition_start = info.start;
682 		hddp->partition_end = info.size;
683 		if (desc->part_type == PART_TYPE_EFI)
684 			hddp->partmap_type = 2;
685 		else
686 			hddp->partmap_type = 1;
687 
688 		switch (desc->sig_type) {
689 		case SIG_TYPE_NONE:
690 		default:
691 			hddp->signature_type = 0;
692 			memset(hddp->partition_signature, 0,
693 			       sizeof(hddp->partition_signature));
694 			break;
695 		case SIG_TYPE_MBR:
696 			hddp->signature_type = 1;
697 			memset(hddp->partition_signature, 0,
698 			       sizeof(hddp->partition_signature));
699 			memcpy(hddp->partition_signature, &desc->mbr_sig,
700 			       sizeof(desc->mbr_sig));
701 			break;
702 		case SIG_TYPE_GUID:
703 			hddp->signature_type = 2;
704 			memcpy(hddp->partition_signature, &desc->guid_sig,
705 			       sizeof(hddp->partition_signature));
706 			break;
707 		}
708 
709 		buf = &hddp[1];
710 	}
711 
712 	return buf;
713 }
714 
715 /*
716  * Create a device path for a block device or one of its partitions.
717  *
718  * @buf		buffer to which the device path is wirtten
719  * @desc	block device descriptor
720  * @part	partition number, 0 identifies a block device
721  */
dp_part_fill(void * buf,struct blk_desc * desc,int part)722 static void *dp_part_fill(void *buf, struct blk_desc *desc, int part)
723 {
724 #ifdef CONFIG_BLK
725 	{
726 		struct udevice *dev;
727 		int ret = blk_find_device(desc->if_type, desc->devnum, &dev);
728 
729 		if (ret)
730 			dev = desc->bdev->parent;
731 		buf = dp_fill(buf, dev);
732 	}
733 #else
734 	/*
735 	 * We *could* make a more accurate path, by looking at if_type
736 	 * and handling all the different cases like we do for non-
737 	 * legacy (ie CONFIG_BLK=y) case.  But most important thing
738 	 * is just to have a unique device-path for if_type+devnum.
739 	 * So map things to a fictitious USB device.
740 	 */
741 	struct efi_device_path_usb *udp;
742 
743 	memcpy(buf, &ROOT, sizeof(ROOT));
744 	buf += sizeof(ROOT);
745 
746 	udp = buf;
747 	udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
748 	udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB;
749 	udp->dp.length = sizeof(*udp);
750 	udp->parent_port_number = desc->if_type;
751 	udp->usb_interface = desc->devnum;
752 	buf = &udp[1];
753 #endif
754 
755 	if (part == 0) /* the actual disk, not a partition */
756 		return buf;
757 
758 	return dp_part_node(buf, desc, part);
759 }
760 
761 /* Construct a device-path from a partition on a blk device: */
efi_dp_from_part(struct blk_desc * desc,int part)762 struct efi_device_path *efi_dp_from_part(struct blk_desc *desc, int part)
763 {
764 	void *buf, *start;
765 
766 	start = buf = dp_alloc(dp_part_size(desc, part) + sizeof(END));
767 	if (!buf)
768 		return NULL;
769 
770 	buf = dp_part_fill(buf, desc, part);
771 
772 	*((struct efi_device_path *)buf) = END;
773 
774 	return start;
775 }
776 
777 /*
778  * Create a device node for a block device partition.
779  *
780  * @buf		buffer to which the device path is wirtten
781  * @desc	block device descriptor
782  * @part	partition number, 0 identifies a block device
783  */
efi_dp_part_node(struct blk_desc * desc,int part)784 struct efi_device_path *efi_dp_part_node(struct blk_desc *desc, int part)
785 {
786 	efi_uintn_t dpsize;
787 	void *buf;
788 
789 	if (desc->part_type == PART_TYPE_ISO)
790 		dpsize = sizeof(struct efi_device_path_cdrom_path);
791 	else
792 		dpsize = sizeof(struct efi_device_path_hard_drive_path);
793 	buf = dp_alloc(dpsize);
794 
795 	dp_part_node(buf, desc, part);
796 
797 	return buf;
798 }
799 
800 /* convert path to an UEFI style path (ie. DOS style backslashes and utf16) */
path_to_uefi(u16 * uefi,const char * path)801 static void path_to_uefi(u16 *uefi, const char *path)
802 {
803 	while (*path) {
804 		char c = *(path++);
805 		if (c == '/')
806 			c = '\\';
807 		*(uefi++) = c;
808 	}
809 	*uefi = '\0';
810 }
811 
812 /*
813  * If desc is NULL, this creates a path with only the file component,
814  * otherwise it creates a full path with both device and file components
815  */
efi_dp_from_file(struct blk_desc * desc,int part,const char * path)816 struct efi_device_path *efi_dp_from_file(struct blk_desc *desc, int part,
817 		const char *path)
818 {
819 	struct efi_device_path_file_path *fp;
820 	void *buf, *start;
821 	unsigned dpsize = 0, fpsize;
822 
823 	if (desc)
824 		dpsize = dp_part_size(desc, part);
825 
826 	fpsize = sizeof(struct efi_device_path) + 2 * (strlen(path) + 1);
827 	dpsize += fpsize;
828 
829 	start = buf = dp_alloc(dpsize + sizeof(END));
830 	if (!buf)
831 		return NULL;
832 
833 	if (desc)
834 		buf = dp_part_fill(buf, desc, part);
835 
836 	/* add file-path: */
837 	fp = buf;
838 	fp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
839 	fp->dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
840 	fp->dp.length = fpsize;
841 	path_to_uefi(fp->str, path);
842 	buf += fpsize;
843 
844 	*((struct efi_device_path *)buf) = END;
845 
846 	return start;
847 }
848 
849 #ifdef CONFIG_NET
efi_dp_from_eth(void)850 struct efi_device_path *efi_dp_from_eth(void)
851 {
852 #ifndef CONFIG_DM_ETH
853 	struct efi_device_path_mac_addr *ndp;
854 #endif
855 	void *buf, *start;
856 	unsigned dpsize = 0;
857 
858 	assert(eth_get_dev());
859 
860 #ifdef CONFIG_DM_ETH
861 	dpsize += dp_size(eth_get_dev());
862 #else
863 	dpsize += sizeof(ROOT);
864 	dpsize += sizeof(*ndp);
865 #endif
866 
867 	start = buf = dp_alloc(dpsize + sizeof(END));
868 	if (!buf)
869 		return NULL;
870 
871 #ifdef CONFIG_DM_ETH
872 	buf = dp_fill(buf, eth_get_dev());
873 #else
874 	memcpy(buf, &ROOT, sizeof(ROOT));
875 	buf += sizeof(ROOT);
876 
877 	ndp = buf;
878 	ndp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
879 	ndp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
880 	ndp->dp.length = sizeof(*ndp);
881 	ndp->if_type = 1; /* Ethernet */
882 	memcpy(ndp->mac.addr, eth_get_ethaddr(), ARP_HLEN);
883 	buf = &ndp[1];
884 #endif
885 
886 	*((struct efi_device_path *)buf) = END;
887 
888 	return start;
889 }
890 #endif
891 
892 /* Construct a device-path for memory-mapped image */
efi_dp_from_mem(uint32_t memory_type,uint64_t start_address,uint64_t end_address)893 struct efi_device_path *efi_dp_from_mem(uint32_t memory_type,
894 					uint64_t start_address,
895 					uint64_t end_address)
896 {
897 	struct efi_device_path_memory *mdp;
898 	void *buf, *start;
899 
900 	start = buf = dp_alloc(sizeof(*mdp) + sizeof(END));
901 	if (!buf)
902 		return NULL;
903 
904 	mdp = buf;
905 	mdp->dp.type = DEVICE_PATH_TYPE_HARDWARE_DEVICE;
906 	mdp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MEMORY;
907 	mdp->dp.length = sizeof(*mdp);
908 	mdp->memory_type = memory_type;
909 	mdp->start_address = start_address;
910 	mdp->end_address = end_address;
911 	buf = &mdp[1];
912 
913 	*((struct efi_device_path *)buf) = END;
914 
915 	return start;
916 }
917 
918 /*
919  * Helper to split a full device path (containing both device and file
920  * parts) into it's constituent parts.
921  */
efi_dp_split_file_path(struct efi_device_path * full_path,struct efi_device_path ** device_path,struct efi_device_path ** file_path)922 efi_status_t efi_dp_split_file_path(struct efi_device_path *full_path,
923 				    struct efi_device_path **device_path,
924 				    struct efi_device_path **file_path)
925 {
926 	struct efi_device_path *p, *dp, *fp;
927 
928 	*device_path = NULL;
929 	*file_path = NULL;
930 	dp = efi_dp_dup(full_path);
931 	if (!dp)
932 		return EFI_OUT_OF_RESOURCES;
933 	p = dp;
934 	while (!EFI_DP_TYPE(p, MEDIA_DEVICE, FILE_PATH)) {
935 		p = efi_dp_next(p);
936 		if (!p)
937 			return EFI_OUT_OF_RESOURCES;
938 	}
939 	fp = efi_dp_dup(p);
940 	if (!fp)
941 		return EFI_OUT_OF_RESOURCES;
942 	p->type = DEVICE_PATH_TYPE_END;
943 	p->sub_type = DEVICE_PATH_SUB_TYPE_END;
944 	p->length = sizeof(*p);
945 
946 	*device_path = dp;
947 	*file_path = fp;
948 	return EFI_SUCCESS;
949 }
950