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 static void *dp_alloc(size_t sz)
43 if (efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, sz, &buf) != EFI_SUCCESS)
50 * Iterate to next block in device-path, terminating (returning NULL)
53 struct efi_device_path *efi_dp_next(const struct efi_device_path *dp)
57 if (dp->type == DEVICE_PATH_TYPE_END)
59 dp = ((void *)dp) + dp->length;
60 if (dp->type == DEVICE_PATH_TYPE_END)
62 return (struct efi_device_path *)dp;
66 * Compare two device-paths, stopping when the shorter of the two hits
67 * an End* node. This is useful to, for example, compare a device-path
68 * representing a device with one representing a file on the device, or
69 * a device with a parent device.
71 int efi_dp_match(const struct efi_device_path *a,
72 const struct efi_device_path *b)
77 ret = memcmp(&a->length, &b->length, sizeof(a->length));
81 ret = memcmp(a, b, a->length);
95 * See UEFI spec (section 3.1.2, about short-form device-paths..
96 * tl;dr: we can have a device-path that starts with a USB WWID
97 * or USB Class node, and a few other cases which don't encode
98 * the full device path with bus hierarchy:
100 * - MESSAGING:USB_WWID
101 * - MESSAGING:USB_CLASS
106 static struct efi_device_path *shorten_path(struct efi_device_path *dp)
110 * TODO: Add MESSAGING:USB_WWID and MESSAGING:URI..
111 * in practice fallback.efi just uses MEDIA:HARD_DRIVE
112 * so not sure when we would see these other cases.
114 if (EFI_DP_TYPE(dp, MESSAGING_DEVICE, MSG_USB_CLASS) ||
115 EFI_DP_TYPE(dp, MEDIA_DEVICE, HARD_DRIVE_PATH) ||
116 EFI_DP_TYPE(dp, MEDIA_DEVICE, FILE_PATH))
119 dp = efi_dp_next(dp);
125 static struct efi_object *find_obj(struct efi_device_path *dp, bool short_path,
126 struct efi_device_path **rem)
128 struct efi_object *efiobj;
130 list_for_each_entry(efiobj, &efi_obj_list, link) {
131 struct efi_handler *handler;
132 struct efi_device_path *obj_dp;
135 ret = efi_search_protocol(efiobj->handle,
136 &efi_guid_device_path, &handler);
137 if (ret != EFI_SUCCESS)
139 obj_dp = handler->protocol_interface;
142 if (efi_dp_match(dp, obj_dp) == 0) {
144 *rem = ((void *)dp) +
150 obj_dp = shorten_path(efi_dp_next(obj_dp));
151 } while (short_path && obj_dp);
159 * Find an efiobj from device-path, if 'rem' is not NULL, returns the
160 * remaining part of the device path after the matched object.
162 struct efi_object *efi_dp_find_obj(struct efi_device_path *dp,
163 struct efi_device_path **rem)
165 struct efi_object *efiobj;
167 efiobj = find_obj(dp, false, rem);
170 efiobj = find_obj(dp, true, rem);
175 /* return size not including End node: */
176 unsigned efi_dp_size(const struct efi_device_path *dp)
182 dp = efi_dp_next(dp);
188 struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp)
190 struct efi_device_path *ndp;
191 unsigned sz = efi_dp_size(dp) + sizeof(END);
202 struct efi_device_path *efi_dp_append(const struct efi_device_path *dp1,
203 const struct efi_device_path *dp2)
205 struct efi_device_path *ret;
208 ret = efi_dp_dup(dp2);
210 ret = efi_dp_dup(dp1);
212 /* both dp1 and dp2 are non-null */
213 unsigned sz1 = efi_dp_size(dp1);
214 unsigned sz2 = efi_dp_size(dp2);
215 void *p = dp_alloc(sz1 + sz2 + sizeof(END));
217 memcpy(p + sz1, dp2, sz2);
218 memcpy(p + sz1 + sz2, &END, sizeof(END));
225 struct efi_device_path *efi_dp_append_node(const struct efi_device_path *dp,
226 const struct efi_device_path *node)
228 struct efi_device_path *ret;
231 ret = efi_dp_dup(&END);
233 ret = efi_dp_dup(dp);
235 unsigned sz = node->length;
236 void *p = dp_alloc(sz + sizeof(END));
238 memcpy(p + sz, &END, sizeof(END));
241 /* both dp and node are non-null */
242 unsigned sz = efi_dp_size(dp);
243 void *p = dp_alloc(sz + node->length + sizeof(END));
245 memcpy(p + sz, node, node->length);
246 memcpy(p + sz + node->length, &END, sizeof(END));
254 /* size of device-path not including END node for device and all parents
255 * up to the root device.
257 static unsigned dp_size(struct udevice *dev)
259 if (!dev || !dev->driver)
262 switch (dev->driver->id) {
264 case UCLASS_SIMPLE_BUS:
265 /* stop traversing parents at this point: */
268 return dp_size(dev->parent) +
269 sizeof(struct efi_device_path_sd_mmc_path);
270 case UCLASS_MASS_STORAGE:
272 return dp_size(dev->parent) +
273 sizeof(struct efi_device_path_usb_class);
275 /* just skip over unknown classes: */
276 return dp_size(dev->parent);
280 static void *dp_fill(void *buf, struct udevice *dev)
282 if (!dev || !dev->driver)
285 switch (dev->driver->id) {
287 case UCLASS_SIMPLE_BUS: {
288 /* stop traversing parents at this point: */
289 struct efi_device_path_vendor *vdp = buf;
293 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
295 struct efi_device_path_sd_mmc_path *sddp =
296 dp_fill(buf, dev->parent);
297 struct mmc *mmc = mmc_get_mmc_dev(dev);
298 struct blk_desc *desc = mmc_get_blk_desc(mmc);
300 sddp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
301 sddp->dp.sub_type = (desc->if_type == IF_TYPE_MMC) ?
302 DEVICE_PATH_SUB_TYPE_MSG_MMC :
303 DEVICE_PATH_SUB_TYPE_MSG_SD;
304 sddp->dp.length = sizeof(*sddp);
305 sddp->slot_number = dev->seq;
310 case UCLASS_MASS_STORAGE:
311 case UCLASS_USB_HUB: {
312 struct efi_device_path_usb_class *udp =
313 dp_fill(buf, dev->parent);
314 struct usb_device *udev = dev_get_parent_priv(dev);
315 struct usb_device_descriptor *desc = &udev->descriptor;
317 udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
318 udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS;
319 udp->dp.length = sizeof(*udp);
320 udp->vendor_id = desc->idVendor;
321 udp->product_id = desc->idProduct;
322 udp->device_class = desc->bDeviceClass;
323 udp->device_subclass = desc->bDeviceSubClass;
324 udp->device_protocol = desc->bDeviceProtocol;
329 debug("unhandled device class: %s (%u)\n",
330 dev->name, dev->driver->id);
331 return dp_fill(buf, dev->parent);
335 /* Construct a device-path from a device: */
336 struct efi_device_path *efi_dp_from_dev(struct udevice *dev)
340 start = buf = dp_alloc(dp_size(dev) + sizeof(END));
341 buf = dp_fill(buf, dev);
342 *((struct efi_device_path *)buf) = END;
348 static unsigned dp_part_size(struct blk_desc *desc, int part)
353 dpsize = dp_size(desc->bdev->parent);
355 dpsize = sizeof(ROOT) + sizeof(struct efi_device_path_usb);
358 if (part == 0) /* the actual disk, not a partition */
361 if (desc->part_type == PART_TYPE_ISO)
362 dpsize += sizeof(struct efi_device_path_cdrom_path);
364 dpsize += sizeof(struct efi_device_path_hard_drive_path);
369 static void *dp_part_fill(void *buf, struct blk_desc *desc, int part)
371 disk_partition_t info;
374 buf = dp_fill(buf, desc->bdev->parent);
377 * We *could* make a more accurate path, by looking at if_type
378 * and handling all the different cases like we do for non-
379 * legacy (ie CONFIG_BLK=y) case. But most important thing
380 * is just to have a unique device-path for if_type+devnum.
381 * So map things to a fictional USB device:
383 struct efi_device_path_usb *udp;
385 memcpy(buf, &ROOT, sizeof(ROOT));
389 udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
390 udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB;
391 udp->dp.length = sizeof(*udp);
392 udp->parent_port_number = desc->if_type;
393 udp->usb_interface = desc->devnum;
397 if (part == 0) /* the actual disk, not a partition */
400 part_get_info(desc, part, &info);
402 if (desc->part_type == PART_TYPE_ISO) {
403 struct efi_device_path_cdrom_path *cddp = buf;
405 cddp->boot_entry = part - 1;
406 cddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
407 cddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_CDROM_PATH;
408 cddp->dp.length = sizeof(*cddp);
409 cddp->partition_start = info.start;
410 cddp->partition_end = info.size;
414 struct efi_device_path_hard_drive_path *hddp = buf;
416 hddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
417 hddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH;
418 hddp->dp.length = sizeof(*hddp);
419 hddp->partition_number = part - 1;
420 hddp->partition_start = info.start;
421 hddp->partition_end = info.size;
422 if (desc->part_type == PART_TYPE_EFI)
423 hddp->partmap_type = 2;
425 hddp->partmap_type = 1;
427 switch (desc->sig_type) {
430 hddp->signature_type = 0;
431 memset(hddp->partition_signature, 0,
432 sizeof(hddp->partition_signature));
435 hddp->signature_type = 1;
436 memset(hddp->partition_signature, 0,
437 sizeof(hddp->partition_signature));
438 memcpy(hddp->partition_signature, &desc->mbr_sig,
439 sizeof(desc->mbr_sig));
442 hddp->signature_type = 2;
443 memcpy(hddp->partition_signature, &desc->guid_sig,
444 sizeof(hddp->partition_signature));
455 /* Construct a device-path from a partition on a blk device: */
456 struct efi_device_path *efi_dp_from_part(struct blk_desc *desc, int part)
460 start = buf = dp_alloc(dp_part_size(desc, part) + sizeof(END));
462 buf = dp_part_fill(buf, desc, part);
464 *((struct efi_device_path *)buf) = END;
469 /* convert path to an UEFI style path (ie. DOS style backslashes and utf16) */
470 static void path_to_uefi(u16 *uefi, const char *path)
482 * If desc is NULL, this creates a path with only the file component,
483 * otherwise it creates a full path with both device and file components
485 struct efi_device_path *efi_dp_from_file(struct blk_desc *desc, int part,
488 struct efi_device_path_file_path *fp;
490 unsigned dpsize = 0, fpsize;
493 dpsize = dp_part_size(desc, part);
495 fpsize = sizeof(struct efi_device_path) + 2 * (strlen(path) + 1);
498 start = buf = dp_alloc(dpsize + sizeof(END));
501 buf = dp_part_fill(buf, desc, part);
505 fp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
506 fp->dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
507 fp->dp.length = fpsize;
508 path_to_uefi(fp->str, path);
511 *((struct efi_device_path *)buf) = END;
517 struct efi_device_path *efi_dp_from_eth(void)
519 struct efi_device_path_mac_addr *ndp;
523 assert(eth_get_dev());
526 dpsize += dp_size(eth_get_dev());
528 dpsize += sizeof(ROOT);
530 dpsize += sizeof(*ndp);
532 start = buf = dp_alloc(dpsize + sizeof(END));
535 buf = dp_fill(buf, eth_get_dev());
537 memcpy(buf, &ROOT, sizeof(ROOT));
542 ndp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
543 ndp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
544 ndp->dp.length = sizeof(*ndp);
545 memcpy(ndp->mac.addr, eth_get_ethaddr(), ARP_HLEN);
548 *((struct efi_device_path *)buf) = END;
554 /* Construct a device-path for memory-mapped image */
555 struct efi_device_path *efi_dp_from_mem(uint32_t memory_type,
556 uint64_t start_address,
557 uint64_t end_address)
559 struct efi_device_path_memory *mdp;
562 start = buf = dp_alloc(sizeof(*mdp) + sizeof(END));
565 mdp->dp.type = DEVICE_PATH_TYPE_HARDWARE_DEVICE;
566 mdp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MEMORY;
567 mdp->dp.length = sizeof(*mdp);
568 mdp->memory_type = memory_type;
569 mdp->start_address = start_address;
570 mdp->end_address = end_address;
573 *((struct efi_device_path *)buf) = END;
579 * Helper to split a full device path (containing both device and file
580 * parts) into it's constituent parts.
582 void efi_dp_split_file_path(struct efi_device_path *full_path,
583 struct efi_device_path **device_path,
584 struct efi_device_path **file_path)
586 struct efi_device_path *p, *dp, *fp;
588 dp = efi_dp_dup(full_path);
590 while (!EFI_DP_TYPE(p, MEDIA_DEVICE, FILE_PATH))
594 p->type = DEVICE_PATH_TYPE_END;
595 p->sub_type = DEVICE_PATH_SUB_TYPE_END;
596 p->length = sizeof(*p);