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(struct efi_device_path *a, struct efi_device_path *b)
76 ret = memcmp(&a->length, &b->length, sizeof(a->length));
80 ret = memcmp(a, b, a->length);
94 * See UEFI spec (section 3.1.2, about short-form device-paths..
95 * tl;dr: we can have a device-path that starts with a USB WWID
96 * or USB Class node, and a few other cases which don't encode
97 * the full device path with bus hierarchy:
99 * - MESSAGING:USB_WWID
100 * - MESSAGING:USB_CLASS
105 static struct efi_device_path *shorten_path(struct efi_device_path *dp)
109 * TODO: Add MESSAGING:USB_WWID and MESSAGING:URI..
110 * in practice fallback.efi just uses MEDIA:HARD_DRIVE
111 * so not sure when we would see these other cases.
113 if (EFI_DP_TYPE(dp, MESSAGING_DEVICE, MSG_USB_CLASS) ||
114 EFI_DP_TYPE(dp, MEDIA_DEVICE, HARD_DRIVE_PATH) ||
115 EFI_DP_TYPE(dp, MEDIA_DEVICE, FILE_PATH))
118 dp = efi_dp_next(dp);
124 static struct efi_object *find_obj(struct efi_device_path *dp, bool short_path,
125 struct efi_device_path **rem)
127 struct efi_object *efiobj;
129 list_for_each_entry(efiobj, &efi_obj_list, link) {
132 for (i = 0; i < ARRAY_SIZE(efiobj->protocols); i++) {
133 struct efi_handler *handler = &efiobj->protocols[i];
134 struct efi_device_path *obj_dp;
139 if (guidcmp(handler->guid, &efi_guid_device_path))
142 obj_dp = handler->protocol_interface;
145 if (efi_dp_match(dp, obj_dp) == 0) {
147 *rem = ((void *)dp) +
153 obj_dp = shorten_path(efi_dp_next(obj_dp));
154 } while (short_path && obj_dp);
163 * Find an efiobj from device-path, if 'rem' is not NULL, returns the
164 * remaining part of the device path after the matched object.
166 struct efi_object *efi_dp_find_obj(struct efi_device_path *dp,
167 struct efi_device_path **rem)
169 struct efi_object *efiobj;
171 efiobj = find_obj(dp, false, rem);
174 efiobj = find_obj(dp, true, rem);
179 /* return size not including End node: */
180 unsigned efi_dp_size(const struct efi_device_path *dp)
186 dp = efi_dp_next(dp);
192 struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp)
194 struct efi_device_path *ndp;
195 unsigned sz = efi_dp_size(dp) + sizeof(END);
206 struct efi_device_path *efi_dp_append(const struct efi_device_path *dp1,
207 const struct efi_device_path *dp2)
209 struct efi_device_path *ret;
212 ret = efi_dp_dup(dp2);
214 ret = efi_dp_dup(dp1);
216 /* both dp1 and dp2 are non-null */
217 unsigned sz1 = efi_dp_size(dp1);
218 unsigned sz2 = efi_dp_size(dp2);
219 void *p = dp_alloc(sz1 + sz2 + sizeof(END));
221 memcpy(p + sz1, dp2, sz2);
222 memcpy(p + sz1 + sz2, &END, sizeof(END));
229 struct efi_device_path *efi_dp_append_node(const struct efi_device_path *dp,
230 const struct efi_device_path *node)
232 struct efi_device_path *ret;
235 ret = efi_dp_dup(&END);
237 ret = efi_dp_dup(dp);
239 unsigned sz = node->length;
240 void *p = dp_alloc(sz + sizeof(END));
242 memcpy(p + sz, &END, sizeof(END));
245 /* both dp and node are non-null */
246 unsigned sz = efi_dp_size(dp);
247 void *p = dp_alloc(sz + node->length + sizeof(END));
249 memcpy(p + sz, node, node->length);
250 memcpy(p + sz + node->length, &END, sizeof(END));
258 /* size of device-path not including END node for device and all parents
259 * up to the root device.
261 static unsigned dp_size(struct udevice *dev)
263 if (!dev || !dev->driver)
266 switch (dev->driver->id) {
268 case UCLASS_SIMPLE_BUS:
269 /* stop traversing parents at this point: */
272 return dp_size(dev->parent) +
273 sizeof(struct efi_device_path_sd_mmc_path);
274 case UCLASS_MASS_STORAGE:
276 return dp_size(dev->parent) +
277 sizeof(struct efi_device_path_usb_class);
279 /* just skip over unknown classes: */
280 return dp_size(dev->parent);
284 static void *dp_fill(void *buf, struct udevice *dev)
286 if (!dev || !dev->driver)
289 switch (dev->driver->id) {
291 case UCLASS_SIMPLE_BUS: {
292 /* stop traversing parents at this point: */
293 struct efi_device_path_vendor *vdp = buf;
297 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
299 struct efi_device_path_sd_mmc_path *sddp =
300 dp_fill(buf, dev->parent);
301 struct mmc *mmc = mmc_get_mmc_dev(dev);
302 struct blk_desc *desc = mmc_get_blk_desc(mmc);
304 sddp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
305 sddp->dp.sub_type = (desc->if_type == IF_TYPE_MMC) ?
306 DEVICE_PATH_SUB_TYPE_MSG_MMC :
307 DEVICE_PATH_SUB_TYPE_MSG_SD;
308 sddp->dp.length = sizeof(*sddp);
309 sddp->slot_number = dev->seq;
314 case UCLASS_MASS_STORAGE:
315 case UCLASS_USB_HUB: {
316 struct efi_device_path_usb_class *udp =
317 dp_fill(buf, dev->parent);
318 struct usb_device *udev = dev_get_parent_priv(dev);
319 struct usb_device_descriptor *desc = &udev->descriptor;
321 udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
322 udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS;
323 udp->dp.length = sizeof(*udp);
324 udp->vendor_id = desc->idVendor;
325 udp->product_id = desc->idProduct;
326 udp->device_class = desc->bDeviceClass;
327 udp->device_subclass = desc->bDeviceSubClass;
328 udp->device_protocol = desc->bDeviceProtocol;
333 debug("unhandled device class: %s (%u)\n",
334 dev->name, dev->driver->id);
335 return dp_fill(buf, dev->parent);
339 /* Construct a device-path from a device: */
340 struct efi_device_path *efi_dp_from_dev(struct udevice *dev)
344 start = buf = dp_alloc(dp_size(dev) + sizeof(END));
345 buf = dp_fill(buf, dev);
346 *((struct efi_device_path *)buf) = END;
352 static unsigned dp_part_size(struct blk_desc *desc, int part)
357 dpsize = dp_size(desc->bdev->parent);
359 dpsize = sizeof(ROOT) + sizeof(struct efi_device_path_usb);
362 if (part == 0) /* the actual disk, not a partition */
365 if (desc->part_type == PART_TYPE_ISO)
366 dpsize += sizeof(struct efi_device_path_cdrom_path);
368 dpsize += sizeof(struct efi_device_path_hard_drive_path);
373 static void *dp_part_fill(void *buf, struct blk_desc *desc, int part)
375 disk_partition_t info;
378 buf = dp_fill(buf, desc->bdev->parent);
381 * We *could* make a more accurate path, by looking at if_type
382 * and handling all the different cases like we do for non-
383 * legacy (ie CONFIG_BLK=y) case. But most important thing
384 * is just to have a unique device-path for if_type+devnum.
385 * So map things to a fictional USB device:
387 struct efi_device_path_usb *udp;
389 memcpy(buf, &ROOT, sizeof(ROOT));
393 udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
394 udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB;
395 udp->dp.length = sizeof(*udp);
396 udp->parent_port_number = desc->if_type;
397 udp->usb_interface = desc->devnum;
401 if (part == 0) /* the actual disk, not a partition */
404 part_get_info(desc, part, &info);
406 if (desc->part_type == PART_TYPE_ISO) {
407 struct efi_device_path_cdrom_path *cddp = buf;
409 cddp->boot_entry = part - 1;
410 cddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
411 cddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_CDROM_PATH;
412 cddp->dp.length = sizeof(*cddp);
413 cddp->partition_start = info.start;
414 cddp->partition_end = info.size;
418 struct efi_device_path_hard_drive_path *hddp = buf;
420 hddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
421 hddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH;
422 hddp->dp.length = sizeof(*hddp);
423 hddp->partition_number = part - 1;
424 hddp->partition_start = info.start;
425 hddp->partition_end = info.size;
426 if (desc->part_type == PART_TYPE_EFI)
427 hddp->partmap_type = 2;
429 hddp->partmap_type = 1;
430 hddp->signature_type = desc->sig_type;
431 if (hddp->signature_type != 0)
432 memcpy(hddp->partition_signature, &desc->guid_sig,
433 sizeof(hddp->partition_signature));
442 /* Construct a device-path from a partition on a blk device: */
443 struct efi_device_path *efi_dp_from_part(struct blk_desc *desc, int part)
447 start = buf = dp_alloc(dp_part_size(desc, part) + sizeof(END));
449 buf = dp_part_fill(buf, desc, part);
451 *((struct efi_device_path *)buf) = END;
456 /* convert path to an UEFI style path (ie. DOS style backslashes and utf16) */
457 static void path_to_uefi(u16 *uefi, const char *path)
469 * If desc is NULL, this creates a path with only the file component,
470 * otherwise it creates a full path with both device and file components
472 struct efi_device_path *efi_dp_from_file(struct blk_desc *desc, int part,
475 struct efi_device_path_file_path *fp;
477 unsigned dpsize = 0, fpsize;
480 dpsize = dp_part_size(desc, part);
482 fpsize = sizeof(struct efi_device_path) + 2 * (strlen(path) + 1);
485 start = buf = dp_alloc(dpsize + sizeof(END));
488 buf = dp_part_fill(buf, desc, part);
492 fp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
493 fp->dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
494 fp->dp.length = fpsize;
495 path_to_uefi(fp->str, path);
498 *((struct efi_device_path *)buf) = END;
504 struct efi_device_path *efi_dp_from_eth(void)
506 struct efi_device_path_mac_addr *ndp;
510 assert(eth_get_dev());
513 dpsize += dp_size(eth_get_dev());
515 dpsize += sizeof(ROOT);
517 dpsize += sizeof(*ndp);
519 start = buf = dp_alloc(dpsize + sizeof(END));
522 buf = dp_fill(buf, eth_get_dev());
524 memcpy(buf, &ROOT, sizeof(ROOT));
529 ndp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
530 ndp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
531 ndp->dp.length = sizeof(*ndp);
532 memcpy(ndp->mac.addr, eth_get_ethaddr(), ARP_HLEN);
535 *((struct efi_device_path *)buf) = END;
541 /* Construct a device-path for memory-mapped image */
542 struct efi_device_path *efi_dp_from_mem(uint32_t memory_type,
543 uint64_t start_address,
544 uint64_t end_address)
546 struct efi_device_path_memory *mdp;
549 start = buf = dp_alloc(sizeof(*mdp) + sizeof(END));
552 mdp->dp.type = DEVICE_PATH_TYPE_HARDWARE_DEVICE;
553 mdp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MEMORY;
554 mdp->dp.length = sizeof(*mdp);
555 mdp->memory_type = memory_type;
556 mdp->start_address = start_address;
557 mdp->end_address = end_address;
560 *((struct efi_device_path *)buf) = END;
566 * Helper to split a full device path (containing both device and file
567 * parts) into it's constituent parts.
569 void efi_dp_split_file_path(struct efi_device_path *full_path,
570 struct efi_device_path **device_path,
571 struct efi_device_path **file_path)
573 struct efi_device_path *p, *dp, *fp;
575 dp = efi_dp_dup(full_path);
577 while (!EFI_DP_TYPE(p, MEDIA_DEVICE, FILE_PATH))
581 p->type = DEVICE_PATH_TYPE_END;
582 p->sub_type = DEVICE_PATH_SUB_TYPE_END;
583 p->length = sizeof(*p);