git.sur5r.net Git - u-boot/blob - lib/efi_loader/efi_device_path.c

   1 /*
   2  * EFI device path from u-boot device-model mapping
   3  *
   4  * (C) Copyright 2017 Rob Clark
   5  *
   6  * SPDX-License-Identifier:     GPL-2.0+
   7  */
   8
   9 #include <common.h>
  10 #include <blk.h>
  11 #include <dm.h>
  12 #include <usb.h>
  13 #include <mmc.h>
  14 #include <efi_loader.h>
  15 #include <inttypes.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 static void *dp_alloc(size_t sz)
  40 {
  41         void *buf;
  42
  43         if (efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, sz, &buf) != EFI_SUCCESS)
  44                 return NULL;
  45
  46         return buf;
  47 }
  48
  49 /*
  50  * Iterate to next block in device-path, terminating (returning NULL)
  51  * at /End* node.
  52  */
  53 struct efi_device_path *efi_dp_next(const struct efi_device_path *dp)
  54 {
  55         if (dp == NULL)
  56                 return NULL;
  57         if (dp->type == DEVICE_PATH_TYPE_END)
  58                 return NULL;
  59         dp = ((void *)dp) + dp->length;
  60         if (dp->type == DEVICE_PATH_TYPE_END)
  61                 return NULL;
  62         return (struct efi_device_path *)dp;
  63 }
  64
  65 /*
  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.
  70  */
  71 int efi_dp_match(const struct efi_device_path *a,
  72                  const struct efi_device_path *b)
  73 {
  74         while (1) {
  75                 int ret;
  76
  77                 ret = memcmp(&a->length, &b->length, sizeof(a->length));
  78                 if (ret)
  79                         return ret;
  80
  81                 ret = memcmp(a, b, a->length);
  82                 if (ret)
  83                         return ret;
  84
  85                 a = efi_dp_next(a);
  86                 b = efi_dp_next(b);
  87
  88                 if (!a || !b)
  89                         return 0;
  90         }
  91 }
  92
  93
  94 /*
  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:
  99  *
 100  *   - MESSAGING:USB_WWID
 101  *   - MESSAGING:USB_CLASS
 102  *   - MEDIA:FILE_PATH
 103  *   - MEDIA:HARD_DRIVE
 104  *   - MESSAGING:URI
 105  */
 106 static struct efi_device_path *shorten_path(struct efi_device_path *dp)
 107 {
 108         while (dp) {
 109                 /*
 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.
 113                  */
 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))
 117                         return dp;
 118
 119                 dp = efi_dp_next(dp);
 120         }
 121
 122         return dp;
 123 }
 124
 125 static struct efi_object *find_obj(struct efi_device_path *dp, bool short_path,
 126                                    struct efi_device_path **rem)
 127 {
 128         struct efi_object *efiobj;
 129         unsigned int dp_size = efi_dp_size(dp);
 130
 131         list_for_each_entry(efiobj, &efi_obj_list, link) {
 132                 struct efi_handler *handler;
 133                 struct efi_device_path *obj_dp;
 134                 efi_status_t ret;
 135
 136                 ret = efi_search_protocol(efiobj->handle,
 137                                           &efi_guid_device_path, &handler);
 138                 if (ret != EFI_SUCCESS)
 139                         continue;
 140                 obj_dp = handler->protocol_interface;
 141
 142                 do {
 143                         if (efi_dp_match(dp, obj_dp) == 0) {
 144                                 if (rem) {
 145                                         /*
 146                                          * Allow partial matches, but inform
 147                                          * the caller.
 148                                          */
 149                                         *rem = ((void *)dp) +
 150                                                 efi_dp_size(obj_dp);
 151                                         return efiobj;
 152                                 } else {
 153                                         /* Only return on exact matches */
 154                                         if (efi_dp_size(obj_dp) == dp_size)
 155                                                 return efiobj;
 156                                 }
 157                         }
 158
 159                         obj_dp = shorten_path(efi_dp_next(obj_dp));
 160                 } while (short_path && obj_dp);
 161         }
 162
 163         return NULL;
 164 }
 165
 166
 167 /*
 168  * Find an efiobj from device-path, if 'rem' is not NULL, returns the
 169  * remaining part of the device path after the matched object.
 170  */
 171 struct efi_object *efi_dp_find_obj(struct efi_device_path *dp,
 172                                    struct efi_device_path **rem)
 173 {
 174         struct efi_object *efiobj;
 175
 176         /* Search for an exact match first */
 177         efiobj = find_obj(dp, false, NULL);
 178
 179         /* Then for a fuzzy match */
 180         if (!efiobj)
 181                 efiobj = find_obj(dp, false, rem);
 182
 183         /* And now for a fuzzy short match */
 184         if (!efiobj)
 185                 efiobj = find_obj(dp, true, rem);
 186
 187         return efiobj;
 188 }
 189
 190 /* return size not including End node: */
 191 unsigned efi_dp_size(const struct efi_device_path *dp)
 192 {
 193         unsigned sz = 0;
 194
 195         while (dp) {
 196                 sz += dp->length;
 197                 dp = efi_dp_next(dp);
 198         }
 199
 200         return sz;
 201 }
 202
 203 struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp)
 204 {
 205         struct efi_device_path *ndp;
 206         unsigned sz = efi_dp_size(dp) + sizeof(END);
 207
 208         if (!dp)
 209                 return NULL;
 210
 211         ndp = dp_alloc(sz);
 212         memcpy(ndp, dp, sz);
 213
 214         return ndp;
 215 }
 216
 217 struct efi_device_path *efi_dp_append(const struct efi_device_path *dp1,
 218                                       const struct efi_device_path *dp2)
 219 {
 220         struct efi_device_path *ret;
 221
 222         if (!dp1) {
 223                 ret = efi_dp_dup(dp2);
 224         } else if (!dp2) {
 225                 ret = efi_dp_dup(dp1);
 226         } else {
 227                 /* both dp1 and dp2 are non-null */
 228                 unsigned sz1 = efi_dp_size(dp1);
 229                 unsigned sz2 = efi_dp_size(dp2);
 230                 void *p = dp_alloc(sz1 + sz2 + sizeof(END));
 231                 memcpy(p, dp1, sz1);
 232                 memcpy(p + sz1, dp2, sz2);
 233                 memcpy(p + sz1 + sz2, &END, sizeof(END));
 234                 ret = p;
 235         }
 236
 237         return ret;
 238 }
 239
 240 struct efi_device_path *efi_dp_append_node(const struct efi_device_path *dp,
 241                                            const struct efi_device_path *node)
 242 {
 243         struct efi_device_path *ret;
 244
 245         if (!node && !dp) {
 246                 ret = efi_dp_dup(&END);
 247         } else if (!node) {
 248                 ret = efi_dp_dup(dp);
 249         } else if (!dp) {
 250                 unsigned sz = node->length;
 251                 void *p = dp_alloc(sz + sizeof(END));
 252                 memcpy(p, node, sz);
 253                 memcpy(p + sz, &END, sizeof(END));
 254                 ret = p;
 255         } else {
 256                 /* both dp and node are non-null */
 257                 unsigned sz = efi_dp_size(dp);
 258                 void *p = dp_alloc(sz + node->length + sizeof(END));
 259                 memcpy(p, dp, sz);
 260                 memcpy(p + sz, node, node->length);
 261                 memcpy(p + sz + node->length, &END, sizeof(END));
 262                 ret = p;
 263         }
 264
 265         return ret;
 266 }
 267
 268 #ifdef CONFIG_DM
 269 /* size of device-path not including END node for device and all parents
 270  * up to the root device.
 271  */
 272 static unsigned dp_size(struct udevice *dev)
 273 {
 274         if (!dev || !dev->driver)
 275                 return sizeof(ROOT);
 276
 277         switch (dev->driver->id) {
 278         case UCLASS_ROOT:
 279         case UCLASS_SIMPLE_BUS:
 280                 /* stop traversing parents at this point: */
 281                 return sizeof(ROOT);
 282         case UCLASS_MMC:
 283                 return dp_size(dev->parent) +
 284                         sizeof(struct efi_device_path_sd_mmc_path);
 285         case UCLASS_MASS_STORAGE:
 286         case UCLASS_USB_HUB:
 287                 return dp_size(dev->parent) +
 288                         sizeof(struct efi_device_path_usb_class);
 289         default:
 290                 /* just skip over unknown classes: */
 291                 return dp_size(dev->parent);
 292         }
 293 }
 294
 295 static void *dp_fill(void *buf, struct udevice *dev)
 296 {
 297         if (!dev || !dev->driver)
 298                 return buf;
 299
 300         switch (dev->driver->id) {
 301         case UCLASS_ROOT:
 302         case UCLASS_SIMPLE_BUS: {
 303                 /* stop traversing parents at this point: */
 304                 struct efi_device_path_vendor *vdp = buf;
 305                 *vdp = ROOT;
 306                 return &vdp[1];
 307         }
 308 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 309         case UCLASS_MMC: {
 310                 struct efi_device_path_sd_mmc_path *sddp =
 311                         dp_fill(buf, dev->parent);
 312                 struct mmc *mmc = mmc_get_mmc_dev(dev);
 313                 struct blk_desc *desc = mmc_get_blk_desc(mmc);
 314
 315                 sddp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 316                 sddp->dp.sub_type = (desc->if_type == IF_TYPE_MMC) ?
 317                         DEVICE_PATH_SUB_TYPE_MSG_MMC :
 318                         DEVICE_PATH_SUB_TYPE_MSG_SD;
 319                 sddp->dp.length   = sizeof(*sddp);
 320                 sddp->slot_number = dev->seq;
 321
 322                 return &sddp[1];
 323         }
 324 #endif
 325         case UCLASS_MASS_STORAGE:
 326         case UCLASS_USB_HUB: {
 327                 struct efi_device_path_usb_class *udp =
 328                         dp_fill(buf, dev->parent);
 329                 struct usb_device *udev = dev_get_parent_priv(dev);
 330                 struct usb_device_descriptor *desc = &udev->descriptor;
 331
 332                 udp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 333                 udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS;
 334                 udp->dp.length   = sizeof(*udp);
 335                 udp->vendor_id   = desc->idVendor;
 336                 udp->product_id  = desc->idProduct;
 337                 udp->device_class    = desc->bDeviceClass;
 338                 udp->device_subclass = desc->bDeviceSubClass;
 339                 udp->device_protocol = desc->bDeviceProtocol;
 340
 341                 return &udp[1];
 342         }
 343         default:
 344                 debug("unhandled device class: %s (%u)\n",
 345                       dev->name, dev->driver->id);
 346                 return dp_fill(buf, dev->parent);
 347         }
 348 }
 349
 350 /* Construct a device-path from a device: */
 351 struct efi_device_path *efi_dp_from_dev(struct udevice *dev)
 352 {
 353         void *buf, *start;
 354
 355         start = buf = dp_alloc(dp_size(dev) + sizeof(END));
 356         buf = dp_fill(buf, dev);
 357         *((struct efi_device_path *)buf) = END;
 358
 359         return start;
 360 }
 361 #endif
 362
 363 static unsigned dp_part_size(struct blk_desc *desc, int part)
 364 {
 365         unsigned dpsize;
 366
 367 #ifdef CONFIG_BLK
 368         dpsize = dp_size(desc->bdev->parent);
 369 #else
 370         dpsize = sizeof(ROOT) + sizeof(struct efi_device_path_usb);
 371 #endif
 372
 373         if (part == 0) /* the actual disk, not a partition */
 374                 return dpsize;
 375
 376         if (desc->part_type == PART_TYPE_ISO)
 377                 dpsize += sizeof(struct efi_device_path_cdrom_path);
 378         else
 379                 dpsize += sizeof(struct efi_device_path_hard_drive_path);
 380
 381         return dpsize;
 382 }
 383
 384 static void *dp_part_fill(void *buf, struct blk_desc *desc, int part)
 385 {
 386         disk_partition_t info;
 387
 388 #ifdef CONFIG_BLK
 389         buf = dp_fill(buf, desc->bdev->parent);
 390 #else
 391         /*
 392          * We *could* make a more accurate path, by looking at if_type
 393          * and handling all the different cases like we do for non-
 394          * legacy (ie CONFIG_BLK=y) case.  But most important thing
 395          * is just to have a unique device-path for if_type+devnum.
 396          * So map things to a fictional USB device:
 397          */
 398         struct efi_device_path_usb *udp;
 399
 400         memcpy(buf, &ROOT, sizeof(ROOT));
 401         buf += sizeof(ROOT);
 402
 403         udp = buf;
 404         udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 405         udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB;
 406         udp->dp.length = sizeof(*udp);
 407         udp->parent_port_number = desc->if_type;
 408         udp->usb_interface = desc->devnum;
 409         buf = &udp[1];
 410 #endif
 411
 412         if (part == 0) /* the actual disk, not a partition */
 413                 return buf;
 414
 415         part_get_info(desc, part, &info);
 416
 417         if (desc->part_type == PART_TYPE_ISO) {
 418                 struct efi_device_path_cdrom_path *cddp = buf;
 419
 420                 cddp->boot_entry = part - 1;
 421                 cddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 422                 cddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_CDROM_PATH;
 423                 cddp->dp.length = sizeof(*cddp);
 424                 cddp->partition_start = info.start;
 425                 cddp->partition_end = info.size;
 426
 427                 buf = &cddp[1];
 428         } else {
 429                 struct efi_device_path_hard_drive_path *hddp = buf;
 430
 431                 hddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 432                 hddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH;
 433                 hddp->dp.length = sizeof(*hddp);
 434                 hddp->partition_number = part - 1;
 435                 hddp->partition_start = info.start;
 436                 hddp->partition_end = info.size;
 437                 if (desc->part_type == PART_TYPE_EFI)
 438                         hddp->partmap_type = 2;
 439                 else
 440                         hddp->partmap_type = 1;
 441
 442                 switch (desc->sig_type) {
 443                 case SIG_TYPE_NONE:
 444                 default:
 445                         hddp->signature_type = 0;
 446                         memset(hddp->partition_signature, 0,
 447                                sizeof(hddp->partition_signature));
 448                         break;
 449                 case SIG_TYPE_MBR:
 450                         hddp->signature_type = 1;
 451                         memset(hddp->partition_signature, 0,
 452                                sizeof(hddp->partition_signature));
 453                         memcpy(hddp->partition_signature, &desc->mbr_sig,
 454                                sizeof(desc->mbr_sig));
 455                         break;
 456                 case SIG_TYPE_GUID:
 457                         hddp->signature_type = 2;
 458                         memcpy(hddp->partition_signature, &desc->guid_sig,
 459                                sizeof(hddp->partition_signature));
 460                         break;
 461                 }
 462
 463                 buf = &hddp[1];
 464         }
 465
 466         return buf;
 467 }
 468
 469
 470 /* Construct a device-path from a partition on a blk device: */
 471 struct efi_device_path *efi_dp_from_part(struct blk_desc *desc, int part)
 472 {
 473         void *buf, *start;
 474
 475         start = buf = dp_alloc(dp_part_size(desc, part) + sizeof(END));
 476
 477         buf = dp_part_fill(buf, desc, part);
 478
 479         *((struct efi_device_path *)buf) = END;
 480
 481         return start;
 482 }
 483
 484 /* convert path to an UEFI style path (ie. DOS style backslashes and utf16) */
 485 static void path_to_uefi(u16 *uefi, const char *path)
 486 {
 487         while (*path) {
 488                 char c = *(path++);
 489                 if (c == '/')
 490                         c = '\\';
 491                 *(uefi++) = c;
 492         }
 493         *uefi = '\0';
 494 }
 495
 496 /*
 497  * If desc is NULL, this creates a path with only the file component,
 498  * otherwise it creates a full path with both device and file components
 499  */
 500 struct efi_device_path *efi_dp_from_file(struct blk_desc *desc, int part,
 501                 const char *path)
 502 {
 503         struct efi_device_path_file_path *fp;
 504         void *buf, *start;
 505         unsigned dpsize = 0, fpsize;
 506
 507         if (desc)
 508                 dpsize = dp_part_size(desc, part);
 509
 510         fpsize = sizeof(struct efi_device_path) + 2 * (strlen(path) + 1);
 511         dpsize += fpsize;
 512
 513         start = buf = dp_alloc(dpsize + sizeof(END));
 514
 515         if (desc)
 516                 buf = dp_part_fill(buf, desc, part);
 517
 518         /* add file-path: */
 519         fp = buf;
 520         fp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 521         fp->dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
 522         fp->dp.length = fpsize;
 523         path_to_uefi(fp->str, path);
 524         buf += fpsize;
 525
 526         *((struct efi_device_path *)buf) = END;
 527
 528         return start;
 529 }
 530
 531 #ifdef CONFIG_NET
 532 struct efi_device_path *efi_dp_from_eth(void)
 533 {
 534         struct efi_device_path_mac_addr *ndp;
 535         void *buf, *start;
 536         unsigned dpsize = 0;
 537
 538         assert(eth_get_dev());
 539
 540 #ifdef CONFIG_DM_ETH
 541         dpsize += dp_size(eth_get_dev());
 542 #else
 543         dpsize += sizeof(ROOT);
 544 #endif
 545         dpsize += sizeof(*ndp);
 546
 547         start = buf = dp_alloc(dpsize + sizeof(END));
 548
 549 #ifdef CONFIG_DM_ETH
 550         buf = dp_fill(buf, eth_get_dev());
 551 #else
 552         memcpy(buf, &ROOT, sizeof(ROOT));
 553         buf += sizeof(ROOT);
 554 #endif
 555
 556         ndp = buf;
 557         ndp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 558         ndp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
 559         ndp->dp.length = sizeof(*ndp);
 560         memcpy(ndp->mac.addr, eth_get_ethaddr(), ARP_HLEN);
 561         buf = &ndp[1];
 562
 563         *((struct efi_device_path *)buf) = END;
 564
 565         return start;
 566 }
 567 #endif
 568
 569 /* Construct a device-path for memory-mapped image */
 570 struct efi_device_path *efi_dp_from_mem(uint32_t memory_type,
 571                                         uint64_t start_address,
 572                                         uint64_t end_address)
 573 {
 574         struct efi_device_path_memory *mdp;
 575         void *buf, *start;
 576
 577         start = buf = dp_alloc(sizeof(*mdp) + sizeof(END));
 578
 579         mdp = buf;
 580         mdp->dp.type = DEVICE_PATH_TYPE_HARDWARE_DEVICE;
 581         mdp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MEMORY;
 582         mdp->dp.length = sizeof(*mdp);
 583         mdp->memory_type = memory_type;
 584         mdp->start_address = start_address;
 585         mdp->end_address = end_address;
 586         buf = &mdp[1];
 587
 588         *((struct efi_device_path *)buf) = END;
 589
 590         return start;
 591 }
 592
 593 /*
 594  * Helper to split a full device path (containing both device and file
 595  * parts) into it's constituent parts.
 596  */
 597 void efi_dp_split_file_path(struct efi_device_path *full_path,
 598                             struct efi_device_path **device_path,
 599                             struct efi_device_path **file_path)
 600 {
 601         struct efi_device_path *p, *dp, *fp;
 602
 603         dp = efi_dp_dup(full_path);
 604         p = dp;
 605         while (!EFI_DP_TYPE(p, MEDIA_DEVICE, FILE_PATH))
 606                 p = efi_dp_next(p);
 607         fp = efi_dp_dup(p);
 608
 609         p->type = DEVICE_PATH_TYPE_END;
 610         p->sub_type = DEVICE_PATH_SUB_TYPE_END;
 611         p->length = sizeof(*p);
 612
 613         *device_path = dp;
 614         *file_path = fp;
 615 }