2 * EFI device path from u-boot device-model mapping
4 * (C) Copyright 2017 Rob Clark
6 * SPDX-License-Identifier: GPL-2.0+
14 #include <efi_loader.h>
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),
26 EFI_GUID(0xe61d73b9, 0xa384, 0x4acc, \
27 0xae, 0xab, 0x82, 0xe8, 0x28, 0xf3, 0x62, 0x8b)
29 /* template ROOT node: */
30 static const struct efi_device_path_vendor ROOT = {
32 .type = DEVICE_PATH_TYPE_HARDWARE_DEVICE,
33 .sub_type = DEVICE_PATH_SUB_TYPE_VENDOR,
34 .length = sizeof(ROOT),
39 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
41 * Determine if an MMC device is an SD card.
43 * @desc block device descriptor
44 * @return true if the device is an SD card
46 static bool is_sd(struct blk_desc *desc)
48 struct mmc *mmc = find_mmc_device(desc->devnum);
53 return IS_SD(mmc) != 0U;
57 static void *dp_alloc(size_t sz)
61 if (efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, sz, &buf) !=
63 debug("EFI: ERROR: out of memory in %s\n", __func__);
71 * Iterate to next block in device-path, terminating (returning NULL)
74 struct efi_device_path *efi_dp_next(const struct efi_device_path *dp)
78 if (dp->type == DEVICE_PATH_TYPE_END)
80 dp = ((void *)dp) + dp->length;
81 if (dp->type == DEVICE_PATH_TYPE_END)
83 return (struct efi_device_path *)dp;
87 * Compare two device-paths, stopping when the shorter of the two hits
88 * an End* node. This is useful to, for example, compare a device-path
89 * representing a device with one representing a file on the device, or
90 * a device with a parent device.
92 int efi_dp_match(const struct efi_device_path *a,
93 const struct efi_device_path *b)
98 ret = memcmp(&a->length, &b->length, sizeof(a->length));
102 ret = memcmp(a, b, a->length);
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:
121 * - MESSAGING:USB_WWID
122 * - MESSAGING:USB_CLASS
127 static struct efi_device_path *shorten_path(struct efi_device_path *dp)
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.
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))
140 dp = efi_dp_next(dp);
146 static struct efi_object *find_obj(struct efi_device_path *dp, bool short_path,
147 struct efi_device_path **rem)
149 struct efi_object *efiobj;
150 unsigned int dp_size = efi_dp_size(dp);
152 list_for_each_entry(efiobj, &efi_obj_list, link) {
153 struct efi_handler *handler;
154 struct efi_device_path *obj_dp;
157 ret = efi_search_protocol(efiobj->handle,
158 &efi_guid_device_path, &handler);
159 if (ret != EFI_SUCCESS)
161 obj_dp = handler->protocol_interface;
164 if (efi_dp_match(dp, obj_dp) == 0) {
167 * Allow partial matches, but inform
170 *rem = ((void *)dp) +
174 /* Only return on exact matches */
175 if (efi_dp_size(obj_dp) == dp_size)
180 obj_dp = shorten_path(efi_dp_next(obj_dp));
181 } while (short_path && obj_dp);
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.
192 struct efi_object *efi_dp_find_obj(struct efi_device_path *dp,
193 struct efi_device_path **rem)
195 struct efi_object *efiobj;
197 /* Search for an exact match first */
198 efiobj = find_obj(dp, false, NULL);
200 /* Then for a fuzzy match */
202 efiobj = find_obj(dp, false, rem);
204 /* And now for a fuzzy short match */
206 efiobj = find_obj(dp, true, rem);
211 /* return size not including End node: */
212 unsigned efi_dp_size(const struct efi_device_path *dp)
218 dp = efi_dp_next(dp);
224 struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp)
226 struct efi_device_path *ndp;
227 unsigned sz = efi_dp_size(dp) + sizeof(END);
240 struct efi_device_path *efi_dp_append(const struct efi_device_path *dp1,
241 const struct efi_device_path *dp2)
243 struct efi_device_path *ret;
246 ret = efi_dp_dup(dp2);
248 ret = efi_dp_dup(dp1);
250 /* both dp1 and dp2 are non-null */
251 unsigned sz1 = efi_dp_size(dp1);
252 unsigned sz2 = efi_dp_size(dp2);
253 void *p = dp_alloc(sz1 + sz2 + sizeof(END));
257 memcpy(p + sz1, dp2, sz2);
258 memcpy(p + sz1 + sz2, &END, sizeof(END));
265 struct efi_device_path *efi_dp_append_node(const struct efi_device_path *dp,
266 const struct efi_device_path *node)
268 struct efi_device_path *ret;
271 ret = efi_dp_dup(&END);
273 ret = efi_dp_dup(dp);
275 unsigned sz = node->length;
276 void *p = dp_alloc(sz + sizeof(END));
280 memcpy(p + sz, &END, sizeof(END));
283 /* both dp and node are non-null */
284 unsigned sz = efi_dp_size(dp);
285 void *p = dp_alloc(sz + node->length + sizeof(END));
289 memcpy(p + sz, node, node->length);
290 memcpy(p + sz + node->length, &END, sizeof(END));
298 /* size of device-path not including END node for device and all parents
299 * up to the root device.
301 static unsigned dp_size(struct udevice *dev)
303 if (!dev || !dev->driver)
306 switch (dev->driver->id) {
308 case UCLASS_SIMPLE_BUS:
309 /* stop traversing parents at this point: */
313 switch (dev->parent->uclass->uc_drv->id) {
316 return dp_size(dev->parent) +
317 sizeof(struct efi_device_path_atapi);
319 #if defined(CONFIG_SCSI) && defined(CONFIG_DM_SCSI)
321 return dp_size(dev->parent) +
322 sizeof(struct efi_device_path_scsi);
325 return dp_size(dev->parent);
329 return dp_size(dev->parent) +
330 sizeof(struct efi_device_path_sd_mmc_path);
331 case UCLASS_MASS_STORAGE:
333 return dp_size(dev->parent) +
334 sizeof(struct efi_device_path_usb_class);
336 /* just skip over unknown classes: */
337 return dp_size(dev->parent);
342 * Recursively build a device path.
344 * @buf pointer to the end of the device path
346 * @return pointer to the end of the device path
348 static void *dp_fill(void *buf, struct udevice *dev)
350 if (!dev || !dev->driver)
353 switch (dev->driver->id) {
355 case UCLASS_SIMPLE_BUS: {
356 /* stop traversing parents at this point: */
357 struct efi_device_path_vendor *vdp = buf;
363 switch (dev->parent->uclass->uc_drv->id) {
366 struct efi_device_path_atapi *dp =
367 dp_fill(buf, dev->parent);
368 struct blk_desc *desc = dev_get_uclass_platdata(dev);
370 dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
371 dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_ATAPI;
372 dp->dp.length = sizeof(*dp);
373 dp->logical_unit_number = desc->devnum;
374 dp->primary_secondary = IDE_BUS(desc->devnum);
375 dp->slave_master = desc->devnum %
376 (CONFIG_SYS_IDE_MAXDEVICE /
377 CONFIG_SYS_IDE_MAXBUS);
381 #if defined(CONFIG_SCSI) && defined(CONFIG_DM_SCSI)
383 struct efi_device_path_scsi *dp =
384 dp_fill(buf, dev->parent);
385 struct blk_desc *desc = dev_get_uclass_platdata(dev);
387 dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
388 dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_SCSI;
389 dp->dp.length = sizeof(*dp);
390 dp->logical_unit_number = desc->lun;
391 dp->target_id = desc->target;
396 printf("unhandled parent class: %s (%u)\n",
397 dev->name, dev->driver->id);
398 return dp_fill(buf, dev->parent);
401 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
403 struct efi_device_path_sd_mmc_path *sddp =
404 dp_fill(buf, dev->parent);
405 struct mmc *mmc = mmc_get_mmc_dev(dev);
406 struct blk_desc *desc = mmc_get_blk_desc(mmc);
408 sddp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
409 sddp->dp.sub_type = is_sd(desc) ?
410 DEVICE_PATH_SUB_TYPE_MSG_SD :
411 DEVICE_PATH_SUB_TYPE_MSG_MMC;
412 sddp->dp.length = sizeof(*sddp);
413 sddp->slot_number = dev->seq;
418 case UCLASS_MASS_STORAGE:
419 case UCLASS_USB_HUB: {
420 struct efi_device_path_usb_class *udp =
421 dp_fill(buf, dev->parent);
422 struct usb_device *udev = dev_get_parent_priv(dev);
423 struct usb_device_descriptor *desc = &udev->descriptor;
425 udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
426 udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS;
427 udp->dp.length = sizeof(*udp);
428 udp->vendor_id = desc->idVendor;
429 udp->product_id = desc->idProduct;
430 udp->device_class = desc->bDeviceClass;
431 udp->device_subclass = desc->bDeviceSubClass;
432 udp->device_protocol = desc->bDeviceProtocol;
437 debug("unhandled device class: %s (%u)\n",
438 dev->name, dev->driver->id);
439 return dp_fill(buf, dev->parent);
443 /* Construct a device-path from a device: */
444 struct efi_device_path *efi_dp_from_dev(struct udevice *dev)
448 start = buf = dp_alloc(dp_size(dev) + sizeof(END));
451 buf = dp_fill(buf, dev);
452 *((struct efi_device_path *)buf) = END;
458 static unsigned dp_part_size(struct blk_desc *desc, int part)
465 int ret = blk_find_device(desc->if_type, desc->devnum, &dev);
468 dev = desc->bdev->parent;
469 dpsize = dp_size(dev);
472 dpsize = sizeof(ROOT) + sizeof(struct efi_device_path_usb);
475 if (part == 0) /* the actual disk, not a partition */
478 if (desc->part_type == PART_TYPE_ISO)
479 dpsize += sizeof(struct efi_device_path_cdrom_path);
481 dpsize += sizeof(struct efi_device_path_hard_drive_path);
487 * Create a device path for a block device or one of its partitions.
489 * @buf buffer to which the device path is wirtten
490 * @desc block device descriptor
491 * @part partition number, 0 identifies a block device
493 static void *dp_part_fill(void *buf, struct blk_desc *desc, int part)
495 disk_partition_t info;
500 int ret = blk_find_device(desc->if_type, desc->devnum, &dev);
503 dev = desc->bdev->parent;
504 buf = dp_fill(buf, dev);
508 * We *could* make a more accurate path, by looking at if_type
509 * and handling all the different cases like we do for non-
510 * legacy (ie CONFIG_BLK=y) case. But most important thing
511 * is just to have a unique device-path for if_type+devnum.
512 * So map things to a fictitious USB device.
514 struct efi_device_path_usb *udp;
516 memcpy(buf, &ROOT, sizeof(ROOT));
520 udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
521 udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB;
522 udp->dp.length = sizeof(*udp);
523 udp->parent_port_number = desc->if_type;
524 udp->usb_interface = desc->devnum;
528 if (part == 0) /* the actual disk, not a partition */
531 part_get_info(desc, part, &info);
533 if (desc->part_type == PART_TYPE_ISO) {
534 struct efi_device_path_cdrom_path *cddp = buf;
536 cddp->boot_entry = part;
537 cddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
538 cddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_CDROM_PATH;
539 cddp->dp.length = sizeof(*cddp);
540 cddp->partition_start = info.start;
541 cddp->partition_end = info.size;
545 struct efi_device_path_hard_drive_path *hddp = buf;
547 hddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
548 hddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH;
549 hddp->dp.length = sizeof(*hddp);
550 hddp->partition_number = part;
551 hddp->partition_start = info.start;
552 hddp->partition_end = info.size;
553 if (desc->part_type == PART_TYPE_EFI)
554 hddp->partmap_type = 2;
556 hddp->partmap_type = 1;
558 switch (desc->sig_type) {
561 hddp->signature_type = 0;
562 memset(hddp->partition_signature, 0,
563 sizeof(hddp->partition_signature));
566 hddp->signature_type = 1;
567 memset(hddp->partition_signature, 0,
568 sizeof(hddp->partition_signature));
569 memcpy(hddp->partition_signature, &desc->mbr_sig,
570 sizeof(desc->mbr_sig));
573 hddp->signature_type = 2;
574 memcpy(hddp->partition_signature, &desc->guid_sig,
575 sizeof(hddp->partition_signature));
586 /* Construct a device-path from a partition on a blk device: */
587 struct efi_device_path *efi_dp_from_part(struct blk_desc *desc, int part)
591 start = buf = dp_alloc(dp_part_size(desc, part) + sizeof(END));
595 buf = dp_part_fill(buf, desc, part);
597 *((struct efi_device_path *)buf) = END;
602 /* convert path to an UEFI style path (ie. DOS style backslashes and utf16) */
603 static void path_to_uefi(u16 *uefi, const char *path)
615 * If desc is NULL, this creates a path with only the file component,
616 * otherwise it creates a full path with both device and file components
618 struct efi_device_path *efi_dp_from_file(struct blk_desc *desc, int part,
621 struct efi_device_path_file_path *fp;
623 unsigned dpsize = 0, fpsize;
626 dpsize = dp_part_size(desc, part);
628 fpsize = sizeof(struct efi_device_path) + 2 * (strlen(path) + 1);
631 start = buf = dp_alloc(dpsize + sizeof(END));
636 buf = dp_part_fill(buf, desc, part);
640 fp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
641 fp->dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
642 fp->dp.length = fpsize;
643 path_to_uefi(fp->str, path);
646 *((struct efi_device_path *)buf) = END;
652 struct efi_device_path *efi_dp_from_eth(void)
654 struct efi_device_path_mac_addr *ndp;
658 assert(eth_get_dev());
661 dpsize += dp_size(eth_get_dev());
663 dpsize += sizeof(ROOT);
665 dpsize += sizeof(*ndp);
667 start = buf = dp_alloc(dpsize + sizeof(END));
672 buf = dp_fill(buf, eth_get_dev());
674 memcpy(buf, &ROOT, sizeof(ROOT));
679 ndp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
680 ndp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
681 ndp->dp.length = sizeof(*ndp);
682 memcpy(ndp->mac.addr, eth_get_ethaddr(), ARP_HLEN);
685 *((struct efi_device_path *)buf) = END;
691 /* Construct a device-path for memory-mapped image */
692 struct efi_device_path *efi_dp_from_mem(uint32_t memory_type,
693 uint64_t start_address,
694 uint64_t end_address)
696 struct efi_device_path_memory *mdp;
699 start = buf = dp_alloc(sizeof(*mdp) + sizeof(END));
704 mdp->dp.type = DEVICE_PATH_TYPE_HARDWARE_DEVICE;
705 mdp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MEMORY;
706 mdp->dp.length = sizeof(*mdp);
707 mdp->memory_type = memory_type;
708 mdp->start_address = start_address;
709 mdp->end_address = end_address;
712 *((struct efi_device_path *)buf) = END;
718 * Helper to split a full device path (containing both device and file
719 * parts) into it's constituent parts.
721 efi_status_t efi_dp_split_file_path(struct efi_device_path *full_path,
722 struct efi_device_path **device_path,
723 struct efi_device_path **file_path)
725 struct efi_device_path *p, *dp, *fp;
729 dp = efi_dp_dup(full_path);
731 return EFI_OUT_OF_RESOURCES;
733 while (!EFI_DP_TYPE(p, MEDIA_DEVICE, FILE_PATH)) {
736 return EFI_OUT_OF_RESOURCES;
740 return EFI_OUT_OF_RESOURCES;
741 p->type = DEVICE_PATH_TYPE_END;
742 p->sub_type = DEVICE_PATH_SUB_TYPE_END;
743 p->length = sizeof(*p);