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 #define LOG_CATEGORY LOGL_ERR
  10
  11 #include <common.h>
  12 #include <blk.h>
  13 #include <dm.h>
  14 #include <usb.h>
  15 #include <mmc.h>
  16 #include <efi_loader.h>
  17 #include <inttypes.h>
  18 #include <part.h>
  19
  20 /* template END node: */
  21 static const struct efi_device_path END = {
  22         .type     = DEVICE_PATH_TYPE_END,
  23         .sub_type = DEVICE_PATH_SUB_TYPE_END,
  24         .length   = sizeof(END),
  25 };
  26
  27 #define U_BOOT_GUID \
  28         EFI_GUID(0xe61d73b9, 0xa384, 0x4acc, \
  29                  0xae, 0xab, 0x82, 0xe8, 0x28, 0xf3, 0x62, 0x8b)
  30
  31 /* template ROOT node: */
  32 static const struct efi_device_path_vendor ROOT = {
  33         .dp = {
  34                 .type     = DEVICE_PATH_TYPE_HARDWARE_DEVICE,
  35                 .sub_type = DEVICE_PATH_SUB_TYPE_VENDOR,
  36                 .length   = sizeof(ROOT),
  37         },
  38         .guid = U_BOOT_GUID,
  39 };
  40
  41 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
  42 /*
  43  * Determine if an MMC device is an SD card.
  44  *
  45  * @desc        block device descriptor
  46  * @return      true if the device is an SD card
  47  */
  48 static bool is_sd(struct blk_desc *desc)
  49 {
  50         struct mmc *mmc = find_mmc_device(desc->devnum);
  51
  52         if (!mmc)
  53                 return false;
  54
  55         return IS_SD(mmc) != 0U;
  56 }
  57 #endif
  58
  59 static void *dp_alloc(size_t sz)
  60 {
  61         void *buf;
  62
  63         if (efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, sz, &buf) !=
  64             EFI_SUCCESS) {
  65                 debug("EFI: ERROR: out of memory in %s\n", __func__);
  66                 return NULL;
  67         }
  68
  69         memset(buf, 0, sz);
  70         return buf;
  71 }
  72
  73 /*
  74  * Iterate to next block in device-path, terminating (returning NULL)
  75  * at /End* node.
  76  */
  77 struct efi_device_path *efi_dp_next(const struct efi_device_path *dp)
  78 {
  79         if (dp == NULL)
  80                 return NULL;
  81         if (dp->type == DEVICE_PATH_TYPE_END)
  82                 return NULL;
  83         dp = ((void *)dp) + dp->length;
  84         if (dp->type == DEVICE_PATH_TYPE_END)
  85                 return NULL;
  86         return (struct efi_device_path *)dp;
  87 }
  88
  89 /*
  90  * Compare two device-paths, stopping when the shorter of the two hits
  91  * an End* node.  This is useful to, for example, compare a device-path
  92  * representing a device with one representing a file on the device, or
  93  * a device with a parent device.
  94  */
  95 int efi_dp_match(const struct efi_device_path *a,
  96                  const struct efi_device_path *b)
  97 {
  98         while (1) {
  99                 int ret;
 100
 101                 ret = memcmp(&a->length, &b->length, sizeof(a->length));
 102                 if (ret)
 103                         return ret;
 104
 105                 ret = memcmp(a, b, a->length);
 106                 if (ret)
 107                         return ret;
 108
 109                 a = efi_dp_next(a);
 110                 b = efi_dp_next(b);
 111
 112                 if (!a || !b)
 113                         return 0;
 114         }
 115 }
 116
 117 /*
 118  * See UEFI spec (section 3.1.2, about short-form device-paths..
 119  * tl;dr: we can have a device-path that starts with a USB WWID
 120  * or USB Class node, and a few other cases which don't encode
 121  * the full device path with bus hierarchy:
 122  *
 123  *   - MESSAGING:USB_WWID
 124  *   - MESSAGING:USB_CLASS
 125  *   - MEDIA:FILE_PATH
 126  *   - MEDIA:HARD_DRIVE
 127  *   - MESSAGING:URI
 128  */
 129 static struct efi_device_path *shorten_path(struct efi_device_path *dp)
 130 {
 131         while (dp) {
 132                 /*
 133                  * TODO: Add MESSAGING:USB_WWID and MESSAGING:URI..
 134                  * in practice fallback.efi just uses MEDIA:HARD_DRIVE
 135                  * so not sure when we would see these other cases.
 136                  */
 137                 if (EFI_DP_TYPE(dp, MESSAGING_DEVICE, MSG_USB_CLASS) ||
 138                     EFI_DP_TYPE(dp, MEDIA_DEVICE, HARD_DRIVE_PATH) ||
 139                     EFI_DP_TYPE(dp, MEDIA_DEVICE, FILE_PATH))
 140                         return dp;
 141
 142                 dp = efi_dp_next(dp);
 143         }
 144
 145         return dp;
 146 }
 147
 148 static struct efi_object *find_obj(struct efi_device_path *dp, bool short_path,
 149                                    struct efi_device_path **rem)
 150 {
 151         struct efi_object *efiobj;
 152         unsigned int dp_size = efi_dp_size(dp);
 153
 154         list_for_each_entry(efiobj, &efi_obj_list, link) {
 155                 struct efi_handler *handler;
 156                 struct efi_device_path *obj_dp;
 157                 efi_status_t ret;
 158
 159                 ret = efi_search_protocol(efiobj->handle,
 160                                           &efi_guid_device_path, &handler);
 161                 if (ret != EFI_SUCCESS)
 162                         continue;
 163                 obj_dp = handler->protocol_interface;
 164
 165                 do {
 166                         if (efi_dp_match(dp, obj_dp) == 0) {
 167                                 if (rem) {
 168                                         /*
 169                                          * Allow partial matches, but inform
 170                                          * the caller.
 171                                          */
 172                                         *rem = ((void *)dp) +
 173                                                 efi_dp_size(obj_dp);
 174                                         return efiobj;
 175                                 } else {
 176                                         /* Only return on exact matches */
 177                                         if (efi_dp_size(obj_dp) == 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  */
 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  */
 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 /* return size not including End node: */
 233 unsigned efi_dp_size(const struct efi_device_path *dp)
 234 {
 235         unsigned sz = 0;
 236
 237         while (dp) {
 238                 sz += dp->length;
 239                 dp = efi_dp_next(dp);
 240         }
 241
 242         return sz;
 243 }
 244
 245 struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp)
 246 {
 247         struct efi_device_path *ndp;
 248         unsigned sz = efi_dp_size(dp) + sizeof(END);
 249
 250         if (!dp)
 251                 return NULL;
 252
 253         ndp = dp_alloc(sz);
 254         if (!ndp)
 255                 return NULL;
 256         memcpy(ndp, dp, sz);
 257
 258         return ndp;
 259 }
 260
 261 struct efi_device_path *efi_dp_append(const struct efi_device_path *dp1,
 262                                       const struct efi_device_path *dp2)
 263 {
 264         struct efi_device_path *ret;
 265
 266         if (!dp1) {
 267                 ret = efi_dp_dup(dp2);
 268         } else if (!dp2) {
 269                 ret = efi_dp_dup(dp1);
 270         } else {
 271                 /* both dp1 and dp2 are non-null */
 272                 unsigned sz1 = efi_dp_size(dp1);
 273                 unsigned sz2 = efi_dp_size(dp2);
 274                 void *p = dp_alloc(sz1 + sz2 + sizeof(END));
 275                 if (!p)
 276                         return NULL;
 277                 memcpy(p, dp1, sz1);
 278                 memcpy(p + sz1, dp2, sz2);
 279                 memcpy(p + sz1 + sz2, &END, sizeof(END));
 280                 ret = p;
 281         }
 282
 283         return ret;
 284 }
 285
 286 struct efi_device_path *efi_dp_append_node(const struct efi_device_path *dp,
 287                                            const struct efi_device_path *node)
 288 {
 289         struct efi_device_path *ret;
 290
 291         if (!node && !dp) {
 292                 ret = efi_dp_dup(&END);
 293         } else if (!node) {
 294                 ret = efi_dp_dup(dp);
 295         } else if (!dp) {
 296                 unsigned sz = node->length;
 297                 void *p = dp_alloc(sz + sizeof(END));
 298                 if (!p)
 299                         return NULL;
 300                 memcpy(p, node, sz);
 301                 memcpy(p + sz, &END, sizeof(END));
 302                 ret = p;
 303         } else {
 304                 /* both dp and node are non-null */
 305                 unsigned sz = efi_dp_size(dp);
 306                 void *p = dp_alloc(sz + node->length + sizeof(END));
 307                 if (!p)
 308                         return NULL;
 309                 memcpy(p, dp, sz);
 310                 memcpy(p + sz, node, node->length);
 311                 memcpy(p + sz + node->length, &END, sizeof(END));
 312                 ret = p;
 313         }
 314
 315         return ret;
 316 }
 317
 318 #ifdef CONFIG_DM
 319 /* size of device-path not including END node for device and all parents
 320  * up to the root device.
 321  */
 322 static unsigned dp_size(struct udevice *dev)
 323 {
 324         if (!dev || !dev->driver)
 325                 return sizeof(ROOT);
 326
 327         switch (dev->driver->id) {
 328         case UCLASS_ROOT:
 329         case UCLASS_SIMPLE_BUS:
 330                 /* stop traversing parents at this point: */
 331                 return sizeof(ROOT);
 332         case UCLASS_ETH:
 333                 return dp_size(dev->parent) +
 334                         sizeof(struct efi_device_path_mac_addr);
 335 #ifdef CONFIG_BLK
 336         case UCLASS_BLK:
 337                 switch (dev->parent->uclass->uc_drv->id) {
 338 #ifdef CONFIG_IDE
 339                 case UCLASS_IDE:
 340                         return dp_size(dev->parent) +
 341                                 sizeof(struct efi_device_path_atapi);
 342 #endif
 343 #if defined(CONFIG_SCSI) && defined(CONFIG_DM_SCSI)
 344                 case UCLASS_SCSI:
 345                         return dp_size(dev->parent) +
 346                                 sizeof(struct efi_device_path_scsi);
 347 #endif
 348 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 349                 case UCLASS_MMC:
 350                         return dp_size(dev->parent) +
 351                                 sizeof(struct efi_device_path_sd_mmc_path);
 352 #endif
 353                 default:
 354                         return dp_size(dev->parent);
 355                 }
 356 #endif
 357 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 358         case UCLASS_MMC:
 359                 return dp_size(dev->parent) +
 360                         sizeof(struct efi_device_path_sd_mmc_path);
 361 #endif
 362         case UCLASS_MASS_STORAGE:
 363         case UCLASS_USB_HUB:
 364                 return dp_size(dev->parent) +
 365                         sizeof(struct efi_device_path_usb_class);
 366         default:
 367                 /* just skip over unknown classes: */
 368                 return dp_size(dev->parent);
 369         }
 370 }
 371
 372 /*
 373  * Recursively build a device path.
 374  *
 375  * @buf         pointer to the end of the device path
 376  * @dev         device
 377  * @return      pointer to the end of the device path
 378  */
 379 static void *dp_fill(void *buf, struct udevice *dev)
 380 {
 381         if (!dev || !dev->driver)
 382                 return buf;
 383
 384         switch (dev->driver->id) {
 385         case UCLASS_ROOT:
 386         case UCLASS_SIMPLE_BUS: {
 387                 /* stop traversing parents at this point: */
 388                 struct efi_device_path_vendor *vdp = buf;
 389                 *vdp = ROOT;
 390                 return &vdp[1];
 391         }
 392 #ifdef CONFIG_DM_ETH
 393         case UCLASS_ETH: {
 394                 struct efi_device_path_mac_addr *dp =
 395                         dp_fill(buf, dev->parent);
 396                 struct eth_pdata *pdata = dev->platdata;
 397
 398                 dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 399                 dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
 400                 dp->dp.length = sizeof(*dp);
 401                 memset(&dp->mac, 0, sizeof(dp->mac));
 402                 /* We only support IPv4 */
 403                 memcpy(&dp->mac, &pdata->enetaddr, ARP_HLEN);
 404                 /* Ethernet */
 405                 dp->if_type = 1;
 406                 return &dp[1];
 407         }
 408 #endif
 409 #ifdef CONFIG_BLK
 410         case UCLASS_BLK:
 411                 switch (dev->parent->uclass->uc_drv->id) {
 412 #ifdef CONFIG_IDE
 413                 case UCLASS_IDE: {
 414                         struct efi_device_path_atapi *dp =
 415                         dp_fill(buf, dev->parent);
 416                         struct blk_desc *desc = dev_get_uclass_platdata(dev);
 417
 418                         dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 419                         dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_ATAPI;
 420                         dp->dp.length = sizeof(*dp);
 421                         dp->logical_unit_number = desc->devnum;
 422                         dp->primary_secondary = IDE_BUS(desc->devnum);
 423                         dp->slave_master = desc->devnum %
 424                                 (CONFIG_SYS_IDE_MAXDEVICE /
 425                                  CONFIG_SYS_IDE_MAXBUS);
 426                         return &dp[1];
 427                         }
 428 #endif
 429 #if defined(CONFIG_SCSI) && defined(CONFIG_DM_SCSI)
 430                 case UCLASS_SCSI: {
 431                         struct efi_device_path_scsi *dp =
 432                                 dp_fill(buf, dev->parent);
 433                         struct blk_desc *desc = dev_get_uclass_platdata(dev);
 434
 435                         dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 436                         dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_SCSI;
 437                         dp->dp.length = sizeof(*dp);
 438                         dp->logical_unit_number = desc->lun;
 439                         dp->target_id = desc->target;
 440                         return &dp[1];
 441                         }
 442 #endif
 443 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 444                 case UCLASS_MMC: {
 445                         struct efi_device_path_sd_mmc_path *sddp =
 446                                 dp_fill(buf, dev->parent);
 447                         struct blk_desc *desc = dev_get_uclass_platdata(dev);
 448
 449                         sddp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 450                         sddp->dp.sub_type = is_sd(desc) ?
 451                                 DEVICE_PATH_SUB_TYPE_MSG_SD :
 452                                 DEVICE_PATH_SUB_TYPE_MSG_MMC;
 453                         sddp->dp.length   = sizeof(*sddp);
 454                         sddp->slot_number = dev->seq;
 455                         return &sddp[1];
 456                         }
 457 #endif
 458                 default:
 459                         debug("%s(%u) %s: unhandled parent class: %s (%u)\n",
 460                               __FILE__, __LINE__, __func__,
 461                               dev->name, dev->parent->uclass->uc_drv->id);
 462                         return dp_fill(buf, dev->parent);
 463                 }
 464 #endif
 465 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 466         case UCLASS_MMC: {
 467                 struct efi_device_path_sd_mmc_path *sddp =
 468                         dp_fill(buf, dev->parent);
 469                 struct mmc *mmc = mmc_get_mmc_dev(dev);
 470                 struct blk_desc *desc = mmc_get_blk_desc(mmc);
 471
 472                 sddp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 473                 sddp->dp.sub_type = is_sd(desc) ?
 474                         DEVICE_PATH_SUB_TYPE_MSG_SD :
 475                         DEVICE_PATH_SUB_TYPE_MSG_MMC;
 476                 sddp->dp.length   = sizeof(*sddp);
 477                 sddp->slot_number = dev->seq;
 478
 479                 return &sddp[1];
 480         }
 481 #endif
 482         case UCLASS_MASS_STORAGE:
 483         case UCLASS_USB_HUB: {
 484                 struct efi_device_path_usb_class *udp =
 485                         dp_fill(buf, dev->parent);
 486                 struct usb_device *udev = dev_get_parent_priv(dev);
 487                 struct usb_device_descriptor *desc = &udev->descriptor;
 488
 489                 udp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 490                 udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS;
 491                 udp->dp.length   = sizeof(*udp);
 492                 udp->vendor_id   = desc->idVendor;
 493                 udp->product_id  = desc->idProduct;
 494                 udp->device_class    = desc->bDeviceClass;
 495                 udp->device_subclass = desc->bDeviceSubClass;
 496                 udp->device_protocol = desc->bDeviceProtocol;
 497
 498                 return &udp[1];
 499         }
 500         default:
 501                 debug("%s(%u) %s: unhandled device class: %s (%u)\n",
 502                       __FILE__, __LINE__, __func__,
 503                       dev->name, dev->driver->id);
 504                 return dp_fill(buf, dev->parent);
 505         }
 506 }
 507
 508 /* Construct a device-path from a device: */
 509 struct efi_device_path *efi_dp_from_dev(struct udevice *dev)
 510 {
 511         void *buf, *start;
 512
 513         start = buf = dp_alloc(dp_size(dev) + sizeof(END));
 514         if (!buf)
 515                 return NULL;
 516         buf = dp_fill(buf, dev);
 517         *((struct efi_device_path *)buf) = END;
 518
 519         return start;
 520 }
 521 #endif
 522
 523 static unsigned dp_part_size(struct blk_desc *desc, int part)
 524 {
 525         unsigned dpsize;
 526
 527 #ifdef CONFIG_BLK
 528         {
 529                 struct udevice *dev;
 530                 int ret = blk_find_device(desc->if_type, desc->devnum, &dev);
 531
 532                 if (ret)
 533                         dev = desc->bdev->parent;
 534                 dpsize = dp_size(dev);
 535         }
 536 #else
 537         dpsize = sizeof(ROOT) + sizeof(struct efi_device_path_usb);
 538 #endif
 539
 540         if (part == 0) /* the actual disk, not a partition */
 541                 return dpsize;
 542
 543         if (desc->part_type == PART_TYPE_ISO)
 544                 dpsize += sizeof(struct efi_device_path_cdrom_path);
 545         else
 546                 dpsize += sizeof(struct efi_device_path_hard_drive_path);
 547
 548         return dpsize;
 549 }
 550
 551 /*
 552  * Create a device node for a block device partition.
 553  *
 554  * @buf         buffer to which the device path is wirtten
 555  * @desc        block device descriptor
 556  * @part        partition number, 0 identifies a block device
 557  */
 558 static void *dp_part_node(void *buf, struct blk_desc *desc, int part)
 559 {
 560         disk_partition_t info;
 561
 562         part_get_info(desc, part, &info);
 563
 564         if (desc->part_type == PART_TYPE_ISO) {
 565                 struct efi_device_path_cdrom_path *cddp = buf;
 566
 567                 cddp->boot_entry = part;
 568                 cddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 569                 cddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_CDROM_PATH;
 570                 cddp->dp.length = sizeof(*cddp);
 571                 cddp->partition_start = info.start;
 572                 cddp->partition_end = info.size;
 573
 574                 buf = &cddp[1];
 575         } else {
 576                 struct efi_device_path_hard_drive_path *hddp = buf;
 577
 578                 hddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 579                 hddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH;
 580                 hddp->dp.length = sizeof(*hddp);
 581                 hddp->partition_number = part;
 582                 hddp->partition_start = info.start;
 583                 hddp->partition_end = info.size;
 584                 if (desc->part_type == PART_TYPE_EFI)
 585                         hddp->partmap_type = 2;
 586                 else
 587                         hddp->partmap_type = 1;
 588
 589                 switch (desc->sig_type) {
 590                 case SIG_TYPE_NONE:
 591                 default:
 592                         hddp->signature_type = 0;
 593                         memset(hddp->partition_signature, 0,
 594                                sizeof(hddp->partition_signature));
 595                         break;
 596                 case SIG_TYPE_MBR:
 597                         hddp->signature_type = 1;
 598                         memset(hddp->partition_signature, 0,
 599                                sizeof(hddp->partition_signature));
 600                         memcpy(hddp->partition_signature, &desc->mbr_sig,
 601                                sizeof(desc->mbr_sig));
 602                         break;
 603                 case SIG_TYPE_GUID:
 604                         hddp->signature_type = 2;
 605                         memcpy(hddp->partition_signature, &desc->guid_sig,
 606                                sizeof(hddp->partition_signature));
 607                         break;
 608                 }
 609
 610                 buf = &hddp[1];
 611         }
 612
 613         return buf;
 614 }
 615
 616 /*
 617  * Create a device path for a block device or one of its partitions.
 618  *
 619  * @buf         buffer to which the device path is wirtten
 620  * @desc        block device descriptor
 621  * @part        partition number, 0 identifies a block device
 622  */
 623 static void *dp_part_fill(void *buf, struct blk_desc *desc, int part)
 624 {
 625 #ifdef CONFIG_BLK
 626         {
 627                 struct udevice *dev;
 628                 int ret = blk_find_device(desc->if_type, desc->devnum, &dev);
 629
 630                 if (ret)
 631                         dev = desc->bdev->parent;
 632                 buf = dp_fill(buf, dev);
 633         }
 634 #else
 635         /*
 636          * We *could* make a more accurate path, by looking at if_type
 637          * and handling all the different cases like we do for non-
 638          * legacy (ie CONFIG_BLK=y) case.  But most important thing
 639          * is just to have a unique device-path for if_type+devnum.
 640          * So map things to a fictitious USB device.
 641          */
 642         struct efi_device_path_usb *udp;
 643
 644         memcpy(buf, &ROOT, sizeof(ROOT));
 645         buf += sizeof(ROOT);
 646
 647         udp = buf;
 648         udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 649         udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB;
 650         udp->dp.length = sizeof(*udp);
 651         udp->parent_port_number = desc->if_type;
 652         udp->usb_interface = desc->devnum;
 653         buf = &udp[1];
 654 #endif
 655
 656         if (part == 0) /* the actual disk, not a partition */
 657                 return buf;
 658
 659         return dp_part_node(buf, desc, part);
 660 }
 661
 662 /* Construct a device-path from a partition on a blk device: */
 663 struct efi_device_path *efi_dp_from_part(struct blk_desc *desc, int part)
 664 {
 665         void *buf, *start;
 666
 667         start = buf = dp_alloc(dp_part_size(desc, part) + sizeof(END));
 668         if (!buf)
 669                 return NULL;
 670
 671         buf = dp_part_fill(buf, desc, part);
 672
 673         *((struct efi_device_path *)buf) = END;
 674
 675         return start;
 676 }
 677
 678 /*
 679  * Create a device node for a block device partition.
 680  *
 681  * @buf         buffer to which the device path is wirtten
 682  * @desc        block device descriptor
 683  * @part        partition number, 0 identifies a block device
 684  */
 685 struct efi_device_path *efi_dp_part_node(struct blk_desc *desc, int part)
 686 {
 687         efi_uintn_t dpsize;
 688         void *buf;
 689
 690         if (desc->part_type == PART_TYPE_ISO)
 691                 dpsize = sizeof(struct efi_device_path_cdrom_path);
 692         else
 693                 dpsize = sizeof(struct efi_device_path_hard_drive_path);
 694         buf = dp_alloc(dpsize);
 695
 696         dp_part_node(buf, desc, part);
 697
 698         return buf;
 699 }
 700
 701 /* convert path to an UEFI style path (ie. DOS style backslashes and utf16) */
 702 static void path_to_uefi(u16 *uefi, const char *path)
 703 {
 704         while (*path) {
 705                 char c = *(path++);
 706                 if (c == '/')
 707                         c = '\\';
 708                 *(uefi++) = c;
 709         }
 710         *uefi = '\0';
 711 }
 712
 713 /*
 714  * If desc is NULL, this creates a path with only the file component,
 715  * otherwise it creates a full path with both device and file components
 716  */
 717 struct efi_device_path *efi_dp_from_file(struct blk_desc *desc, int part,
 718                 const char *path)
 719 {
 720         struct efi_device_path_file_path *fp;
 721         void *buf, *start;
 722         unsigned dpsize = 0, fpsize;
 723
 724         if (desc)
 725                 dpsize = dp_part_size(desc, part);
 726
 727         fpsize = sizeof(struct efi_device_path) + 2 * (strlen(path) + 1);
 728         dpsize += fpsize;
 729
 730         start = buf = dp_alloc(dpsize + sizeof(END));
 731         if (!buf)
 732                 return NULL;
 733
 734         if (desc)
 735                 buf = dp_part_fill(buf, desc, part);
 736
 737         /* add file-path: */
 738         fp = buf;
 739         fp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 740         fp->dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
 741         fp->dp.length = fpsize;
 742         path_to_uefi(fp->str, path);
 743         buf += fpsize;
 744
 745         *((struct efi_device_path *)buf) = END;
 746
 747         return start;
 748 }
 749
 750 #ifdef CONFIG_NET
 751 struct efi_device_path *efi_dp_from_eth(void)
 752 {
 753 #ifndef CONFIG_DM_ETH
 754         struct efi_device_path_mac_addr *ndp;
 755 #endif
 756         void *buf, *start;
 757         unsigned dpsize = 0;
 758
 759         assert(eth_get_dev());
 760
 761 #ifdef CONFIG_DM_ETH
 762         dpsize += dp_size(eth_get_dev());
 763 #else
 764         dpsize += sizeof(ROOT);
 765         dpsize += sizeof(*ndp);
 766 #endif
 767
 768         start = buf = dp_alloc(dpsize + sizeof(END));
 769         if (!buf)
 770                 return NULL;
 771
 772 #ifdef CONFIG_DM_ETH
 773         buf = dp_fill(buf, eth_get_dev());
 774 #else
 775         memcpy(buf, &ROOT, sizeof(ROOT));
 776         buf += sizeof(ROOT);
 777
 778         ndp = buf;
 779         ndp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 780         ndp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
 781         ndp->dp.length = sizeof(*ndp);
 782         ndp->if_type = 1; /* Ethernet */
 783         memcpy(ndp->mac.addr, eth_get_ethaddr(), ARP_HLEN);
 784         buf = &ndp[1];
 785 #endif
 786
 787         *((struct efi_device_path *)buf) = END;
 788
 789         return start;
 790 }
 791 #endif
 792
 793 /* Construct a device-path for memory-mapped image */
 794 struct efi_device_path *efi_dp_from_mem(uint32_t memory_type,
 795                                         uint64_t start_address,
 796                                         uint64_t end_address)
 797 {
 798         struct efi_device_path_memory *mdp;
 799         void *buf, *start;
 800
 801         start = buf = dp_alloc(sizeof(*mdp) + sizeof(END));
 802         if (!buf)
 803                 return NULL;
 804
 805         mdp = buf;
 806         mdp->dp.type = DEVICE_PATH_TYPE_HARDWARE_DEVICE;
 807         mdp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MEMORY;
 808         mdp->dp.length = sizeof(*mdp);
 809         mdp->memory_type = memory_type;
 810         mdp->start_address = start_address;
 811         mdp->end_address = end_address;
 812         buf = &mdp[1];
 813
 814         *((struct efi_device_path *)buf) = END;
 815
 816         return start;
 817 }
 818
 819 /*
 820  * Helper to split a full device path (containing both device and file
 821  * parts) into it's constituent parts.
 822  */
 823 efi_status_t efi_dp_split_file_path(struct efi_device_path *full_path,
 824                                     struct efi_device_path **device_path,
 825                                     struct efi_device_path **file_path)
 826 {
 827         struct efi_device_path *p, *dp, *fp;
 828
 829         *device_path = NULL;
 830         *file_path = NULL;
 831         dp = efi_dp_dup(full_path);
 832         if (!dp)
 833                 return EFI_OUT_OF_RESOURCES;
 834         p = dp;
 835         while (!EFI_DP_TYPE(p, MEDIA_DEVICE, FILE_PATH)) {
 836                 p = efi_dp_next(p);
 837                 if (!p)
 838                         return EFI_OUT_OF_RESOURCES;
 839         }
 840         fp = efi_dp_dup(p);
 841         if (!fp)
 842                 return EFI_OUT_OF_RESOURCES;
 843         p->type = DEVICE_PATH_TYPE_END;
 844         p->sub_type = DEVICE_PATH_SUB_TYPE_END;
 845         p->length = sizeof(*p);
 846
 847         *device_path = dp;
 848         *file_path = fp;
 849         return EFI_SUCCESS;
 850 }