lib/efi_loader/efi_device_path.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * EFI device path from u-boot device-model mapping
   4  *
   5  * (C) Copyright 2017 Rob Clark
   6  */
   7
   8 #define LOG_CATEGORY LOGL_ERR
   9
  10 #include <common.h>
  11 #include <blk.h>
  12 #include <dm.h>
  13 #include <usb.h>
  14 #include <mmc.h>
  15 #include <efi_loader.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 /* template ROOT node: */
  26 static const struct efi_device_path_vendor ROOT = {
  27         .dp = {
  28                 .type     = DEVICE_PATH_TYPE_HARDWARE_DEVICE,
  29                 .sub_type = DEVICE_PATH_SUB_TYPE_VENDOR,
  30                 .length   = sizeof(ROOT),
  31         },
  32         .guid = U_BOOT_GUID,
  33 };
  34
  35 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
  36 /*
  37  * Determine if an MMC device is an SD card.
  38  *
  39  * @desc        block device descriptor
  40  * @return      true if the device is an SD card
  41  */
  42 static bool is_sd(struct blk_desc *desc)
  43 {
  44         struct mmc *mmc = find_mmc_device(desc->devnum);
  45
  46         if (!mmc)
  47                 return false;
  48
  49         return IS_SD(mmc) != 0U;
  50 }
  51 #endif
  52
  53 static void *dp_alloc(size_t sz)
  54 {
  55         void *buf;
  56
  57         if (efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, sz, &buf) !=
  58             EFI_SUCCESS) {
  59                 debug("EFI: ERROR: out of memory in %s\n", __func__);
  60                 return NULL;
  61         }
  62
  63         memset(buf, 0, sz);
  64         return buf;
  65 }
  66
  67 /*
  68  * Iterate to next block in device-path, terminating (returning NULL)
  69  * at /End* node.
  70  */
  71 struct efi_device_path *efi_dp_next(const struct efi_device_path *dp)
  72 {
  73         if (dp == NULL)
  74                 return NULL;
  75         if (dp->type == DEVICE_PATH_TYPE_END)
  76                 return NULL;
  77         dp = ((void *)dp) + dp->length;
  78         if (dp->type == DEVICE_PATH_TYPE_END)
  79                 return NULL;
  80         return (struct efi_device_path *)dp;
  81 }
  82
  83 /*
  84  * Compare two device-paths, stopping when the shorter of the two hits
  85  * an End* node.  This is useful to, for example, compare a device-path
  86  * representing a device with one representing a file on the device, or
  87  * a device with a parent device.
  88  */
  89 int efi_dp_match(const struct efi_device_path *a,
  90                  const struct efi_device_path *b)
  91 {
  92         while (1) {
  93                 int ret;
  94
  95                 ret = memcmp(&a->length, &b->length, sizeof(a->length));
  96                 if (ret)
  97                         return ret;
  98
  99                 ret = memcmp(a, b, a->length);
 100                 if (ret)
 101                         return ret;
 102
 103                 a = efi_dp_next(a);
 104                 b = efi_dp_next(b);
 105
 106                 if (!a || !b)
 107                         return 0;
 108         }
 109 }
 110
 111 /*
 112  * See UEFI spec (section 3.1.2, about short-form device-paths..
 113  * tl;dr: we can have a device-path that starts with a USB WWID
 114  * or USB Class node, and a few other cases which don't encode
 115  * the full device path with bus hierarchy:
 116  *
 117  *   - MESSAGING:USB_WWID
 118  *   - MESSAGING:USB_CLASS
 119  *   - MEDIA:FILE_PATH
 120  *   - MEDIA:HARD_DRIVE
 121  *   - MESSAGING:URI
 122  */
 123 static struct efi_device_path *shorten_path(struct efi_device_path *dp)
 124 {
 125         while (dp) {
 126                 /*
 127                  * TODO: Add MESSAGING:USB_WWID and MESSAGING:URI..
 128                  * in practice fallback.efi just uses MEDIA:HARD_DRIVE
 129                  * so not sure when we would see these other cases.
 130                  */
 131                 if (EFI_DP_TYPE(dp, MESSAGING_DEVICE, MSG_USB_CLASS) ||
 132                     EFI_DP_TYPE(dp, MEDIA_DEVICE, HARD_DRIVE_PATH) ||
 133                     EFI_DP_TYPE(dp, MEDIA_DEVICE, FILE_PATH))
 134                         return dp;
 135
 136                 dp = efi_dp_next(dp);
 137         }
 138
 139         return dp;
 140 }
 141
 142 static struct efi_object *find_obj(struct efi_device_path *dp, bool short_path,
 143                                    struct efi_device_path **rem)
 144 {
 145         struct efi_object *efiobj;
 146         efi_uintn_t dp_size = efi_dp_instance_size(dp);
 147
 148         list_for_each_entry(efiobj, &efi_obj_list, link) {
 149                 struct efi_handler *handler;
 150                 struct efi_device_path *obj_dp;
 151                 efi_status_t ret;
 152
 153                 ret = efi_search_protocol(efiobj,
 154                                           &efi_guid_device_path, &handler);
 155                 if (ret != EFI_SUCCESS)
 156                         continue;
 157                 obj_dp = handler->protocol_interface;
 158
 159                 do {
 160                         if (efi_dp_match(dp, obj_dp) == 0) {
 161                                 if (rem) {
 162                                         /*
 163                                          * Allow partial matches, but inform
 164                                          * the caller.
 165                                          */
 166                                         *rem = ((void *)dp) +
 167                                                 efi_dp_instance_size(obj_dp);
 168                                         return efiobj;
 169                                 } else {
 170                                         /* Only return on exact matches */
 171                                         if (efi_dp_instance_size(obj_dp) ==
 172                                             dp_size)
 173                                                 return efiobj;
 174                                 }
 175                         }
 176
 177                         obj_dp = shorten_path(efi_dp_next(obj_dp));
 178                 } while (short_path && obj_dp);
 179         }
 180
 181         return NULL;
 182 }
 183
 184 /*
 185  * Find an efiobj from device-path, if 'rem' is not NULL, returns the
 186  * remaining part of the device path after the matched object.
 187  */
 188 struct efi_object *efi_dp_find_obj(struct efi_device_path *dp,
 189                                    struct efi_device_path **rem)
 190 {
 191         struct efi_object *efiobj;
 192
 193         /* Search for an exact match first */
 194         efiobj = find_obj(dp, false, NULL);
 195
 196         /* Then for a fuzzy match */
 197         if (!efiobj)
 198                 efiobj = find_obj(dp, false, rem);
 199
 200         /* And now for a fuzzy short match */
 201         if (!efiobj)
 202                 efiobj = find_obj(dp, true, rem);
 203
 204         return efiobj;
 205 }
 206
 207 /*
 208  * Determine the last device path node that is not the end node.
 209  *
 210  * @dp          device path
 211  * @return      last node before the end node if it exists
 212  *              otherwise NULL
 213  */
 214 const struct efi_device_path *efi_dp_last_node(const struct efi_device_path *dp)
 215 {
 216         struct efi_device_path *ret;
 217
 218         if (!dp || dp->type == DEVICE_PATH_TYPE_END)
 219                 return NULL;
 220         while (dp) {
 221                 ret = (struct efi_device_path *)dp;
 222                 dp = efi_dp_next(dp);
 223         }
 224         return ret;
 225 }
 226
 227 /* get size of the first device path instance excluding end node */
 228 efi_uintn_t efi_dp_instance_size(const struct efi_device_path *dp)
 229 {
 230         efi_uintn_t sz = 0;
 231
 232         if (!dp || dp->type == DEVICE_PATH_TYPE_END)
 233                 return 0;
 234         while (dp) {
 235                 sz += dp->length;
 236                 dp = efi_dp_next(dp);
 237         }
 238
 239         return sz;
 240 }
 241
 242 /* get size of multi-instance device path excluding end node */
 243 efi_uintn_t efi_dp_size(const struct efi_device_path *dp)
 244 {
 245         const struct efi_device_path *p = dp;
 246
 247         if (!p)
 248                 return 0;
 249         while (p->type != DEVICE_PATH_TYPE_END ||
 250                p->sub_type != DEVICE_PATH_SUB_TYPE_END)
 251                 p = (void *)p + p->length;
 252
 253         return (void *)p - (void *)dp;
 254 }
 255
 256 /* copy multi-instance device path */
 257 struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp)
 258 {
 259         struct efi_device_path *ndp;
 260         size_t sz = efi_dp_size(dp) + sizeof(END);
 261
 262         if (!dp)
 263                 return NULL;
 264
 265         ndp = dp_alloc(sz);
 266         if (!ndp)
 267                 return NULL;
 268         memcpy(ndp, dp, sz);
 269
 270         return ndp;
 271 }
 272
 273 struct efi_device_path *efi_dp_append(const struct efi_device_path *dp1,
 274                                       const struct efi_device_path *dp2)
 275 {
 276         struct efi_device_path *ret;
 277
 278         if (!dp1 && !dp2) {
 279                 /* return an end node */
 280                 ret = efi_dp_dup(&END);
 281         } else if (!dp1) {
 282                 ret = efi_dp_dup(dp2);
 283         } else if (!dp2) {
 284                 ret = efi_dp_dup(dp1);
 285         } else {
 286                 /* both dp1 and dp2 are non-null */
 287                 unsigned sz1 = efi_dp_size(dp1);
 288                 unsigned sz2 = efi_dp_size(dp2);
 289                 void *p = dp_alloc(sz1 + sz2 + sizeof(END));
 290                 if (!p)
 291                         return NULL;
 292                 memcpy(p, dp1, sz1);
 293                 /* the end node of the second device path has to be retained */
 294                 memcpy(p + sz1, dp2, sz2 + sizeof(END));
 295                 ret = p;
 296         }
 297
 298         return ret;
 299 }
 300
 301 struct efi_device_path *efi_dp_append_node(const struct efi_device_path *dp,
 302                                            const struct efi_device_path *node)
 303 {
 304         struct efi_device_path *ret;
 305
 306         if (!node && !dp) {
 307                 ret = efi_dp_dup(&END);
 308         } else if (!node) {
 309                 ret = efi_dp_dup(dp);
 310         } else if (!dp) {
 311                 size_t sz = node->length;
 312                 void *p = dp_alloc(sz + sizeof(END));
 313                 if (!p)
 314                         return NULL;
 315                 memcpy(p, node, sz);
 316                 memcpy(p + sz, &END, sizeof(END));
 317                 ret = p;
 318         } else {
 319                 /* both dp and node are non-null */
 320                 size_t sz = efi_dp_size(dp);
 321                 void *p = dp_alloc(sz + node->length + sizeof(END));
 322                 if (!p)
 323                         return NULL;
 324                 memcpy(p, dp, sz);
 325                 memcpy(p + sz, node, node->length);
 326                 memcpy(p + sz + node->length, &END, sizeof(END));
 327                 ret = p;
 328         }
 329
 330         return ret;
 331 }
 332
 333 struct efi_device_path *efi_dp_create_device_node(const u8 type,
 334                                                   const u8 sub_type,
 335                                                   const u16 length)
 336 {
 337         struct efi_device_path *ret;
 338
 339         ret = dp_alloc(length);
 340         if (!ret)
 341                 return ret;
 342         ret->type = type;
 343         ret->sub_type = sub_type;
 344         ret->length = length;
 345         return ret;
 346 }
 347
 348 struct efi_device_path *efi_dp_append_instance(
 349                 const struct efi_device_path *dp,
 350                 const struct efi_device_path *dpi)
 351 {
 352         size_t sz, szi;
 353         struct efi_device_path *p, *ret;
 354
 355         if (!dpi)
 356                 return NULL;
 357         if (!dp)
 358                 return efi_dp_dup(dpi);
 359         sz = efi_dp_size(dp);
 360         szi = efi_dp_instance_size(dpi);
 361         p = dp_alloc(sz + szi + 2 * sizeof(END));
 362         if (!p)
 363                 return NULL;
 364         ret = p;
 365         memcpy(p, dp, sz + sizeof(END));
 366         p = (void *)p + sz;
 367         p->sub_type = DEVICE_PATH_SUB_TYPE_INSTANCE_END;
 368         p = (void *)p + sizeof(END);
 369         memcpy(p, dpi, szi);
 370         p = (void *)p + szi;
 371         memcpy(p, &END, sizeof(END));
 372         return ret;
 373 }
 374
 375 struct efi_device_path *efi_dp_get_next_instance(struct efi_device_path **dp,
 376                                                  efi_uintn_t *size)
 377 {
 378         size_t sz;
 379         struct efi_device_path *p;
 380
 381         if (size)
 382                 *size = 0;
 383         if (!dp || !*dp)
 384                 return NULL;
 385         sz = efi_dp_instance_size(*dp);
 386         p = dp_alloc(sz + sizeof(END));
 387         if (!p)
 388                 return NULL;
 389         memcpy(p, *dp, sz + sizeof(END));
 390         *dp = (void *)*dp + sz;
 391         if ((*dp)->sub_type == DEVICE_PATH_SUB_TYPE_INSTANCE_END)
 392                 *dp = (void *)*dp + sizeof(END);
 393         else
 394                 *dp = NULL;
 395         if (size)
 396                 *size = sz + sizeof(END);
 397         return p;
 398 }
 399
 400 bool efi_dp_is_multi_instance(const struct efi_device_path *dp)
 401 {
 402         const struct efi_device_path *p = dp;
 403
 404         if (!p)
 405                 return false;
 406         while (p->type != DEVICE_PATH_TYPE_END)
 407                 p = (void *)p + p->length;
 408         return p->sub_type == DEVICE_PATH_SUB_TYPE_INSTANCE_END;
 409 }
 410
 411 #ifdef CONFIG_DM
 412 /* size of device-path not including END node for device and all parents
 413  * up to the root device.
 414  */
 415 static unsigned dp_size(struct udevice *dev)
 416 {
 417         if (!dev || !dev->driver)
 418                 return sizeof(ROOT);
 419
 420         switch (dev->driver->id) {
 421         case UCLASS_ROOT:
 422         case UCLASS_SIMPLE_BUS:
 423                 /* stop traversing parents at this point: */
 424                 return sizeof(ROOT);
 425         case UCLASS_ETH:
 426                 return dp_size(dev->parent) +
 427                         sizeof(struct efi_device_path_mac_addr);
 428 #ifdef CONFIG_BLK
 429         case UCLASS_BLK:
 430                 switch (dev->parent->uclass->uc_drv->id) {
 431 #ifdef CONFIG_IDE
 432                 case UCLASS_IDE:
 433                         return dp_size(dev->parent) +
 434                                 sizeof(struct efi_device_path_atapi);
 435 #endif
 436 #if defined(CONFIG_SCSI) && defined(CONFIG_DM_SCSI)
 437                 case UCLASS_SCSI:
 438                         return dp_size(dev->parent) +
 439                                 sizeof(struct efi_device_path_scsi);
 440 #endif
 441 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 442                 case UCLASS_MMC:
 443                         return dp_size(dev->parent) +
 444                                 sizeof(struct efi_device_path_sd_mmc_path);
 445 #endif
 446                 default:
 447                         return dp_size(dev->parent);
 448                 }
 449 #endif
 450 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 451         case UCLASS_MMC:
 452                 return dp_size(dev->parent) +
 453                         sizeof(struct efi_device_path_sd_mmc_path);
 454 #endif
 455         case UCLASS_MASS_STORAGE:
 456         case UCLASS_USB_HUB:
 457                 return dp_size(dev->parent) +
 458                         sizeof(struct efi_device_path_usb_class);
 459         default:
 460                 /* just skip over unknown classes: */
 461                 return dp_size(dev->parent);
 462         }
 463 }
 464
 465 /*
 466  * Recursively build a device path.
 467  *
 468  * @buf         pointer to the end of the device path
 469  * @dev         device
 470  * @return      pointer to the end of the device path
 471  */
 472 static void *dp_fill(void *buf, struct udevice *dev)
 473 {
 474         if (!dev || !dev->driver)
 475                 return buf;
 476
 477         switch (dev->driver->id) {
 478         case UCLASS_ROOT:
 479         case UCLASS_SIMPLE_BUS: {
 480                 /* stop traversing parents at this point: */
 481                 struct efi_device_path_vendor *vdp = buf;
 482                 *vdp = ROOT;
 483                 return &vdp[1];
 484         }
 485 #ifdef CONFIG_DM_ETH
 486         case UCLASS_ETH: {
 487                 struct efi_device_path_mac_addr *dp =
 488                         dp_fill(buf, dev->parent);
 489                 struct eth_pdata *pdata = dev->platdata;
 490
 491                 dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 492                 dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
 493                 dp->dp.length = sizeof(*dp);
 494                 memset(&dp->mac, 0, sizeof(dp->mac));
 495                 /* We only support IPv4 */
 496                 memcpy(&dp->mac, &pdata->enetaddr, ARP_HLEN);
 497                 /* Ethernet */
 498                 dp->if_type = 1;
 499                 return &dp[1];
 500         }
 501 #endif
 502 #ifdef CONFIG_BLK
 503         case UCLASS_BLK:
 504                 switch (dev->parent->uclass->uc_drv->id) {
 505 #ifdef CONFIG_IDE
 506                 case UCLASS_IDE: {
 507                         struct efi_device_path_atapi *dp =
 508                         dp_fill(buf, dev->parent);
 509                         struct blk_desc *desc = dev_get_uclass_platdata(dev);
 510
 511                         dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 512                         dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_ATAPI;
 513                         dp->dp.length = sizeof(*dp);
 514                         dp->logical_unit_number = desc->devnum;
 515                         dp->primary_secondary = IDE_BUS(desc->devnum);
 516                         dp->slave_master = desc->devnum %
 517                                 (CONFIG_SYS_IDE_MAXDEVICE /
 518                                  CONFIG_SYS_IDE_MAXBUS);
 519                         return &dp[1];
 520                         }
 521 #endif
 522 #if defined(CONFIG_SCSI) && defined(CONFIG_DM_SCSI)
 523                 case UCLASS_SCSI: {
 524                         struct efi_device_path_scsi *dp =
 525                                 dp_fill(buf, dev->parent);
 526                         struct blk_desc *desc = dev_get_uclass_platdata(dev);
 527
 528                         dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 529                         dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_SCSI;
 530                         dp->dp.length = sizeof(*dp);
 531                         dp->logical_unit_number = desc->lun;
 532                         dp->target_id = desc->target;
 533                         return &dp[1];
 534                         }
 535 #endif
 536 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 537                 case UCLASS_MMC: {
 538                         struct efi_device_path_sd_mmc_path *sddp =
 539                                 dp_fill(buf, dev->parent);
 540                         struct blk_desc *desc = dev_get_uclass_platdata(dev);
 541
 542                         sddp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 543                         sddp->dp.sub_type = is_sd(desc) ?
 544                                 DEVICE_PATH_SUB_TYPE_MSG_SD :
 545                                 DEVICE_PATH_SUB_TYPE_MSG_MMC;
 546                         sddp->dp.length   = sizeof(*sddp);
 547                         sddp->slot_number = dev->seq;
 548                         return &sddp[1];
 549                         }
 550 #endif
 551                 default:
 552                         debug("%s(%u) %s: unhandled parent class: %s (%u)\n",
 553                               __FILE__, __LINE__, __func__,
 554                               dev->name, dev->parent->uclass->uc_drv->id);
 555                         return dp_fill(buf, dev->parent);
 556                 }
 557 #endif
 558 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 559         case UCLASS_MMC: {
 560                 struct efi_device_path_sd_mmc_path *sddp =
 561                         dp_fill(buf, dev->parent);
 562                 struct mmc *mmc = mmc_get_mmc_dev(dev);
 563                 struct blk_desc *desc = mmc_get_blk_desc(mmc);
 564
 565                 sddp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 566                 sddp->dp.sub_type = is_sd(desc) ?
 567                         DEVICE_PATH_SUB_TYPE_MSG_SD :
 568                         DEVICE_PATH_SUB_TYPE_MSG_MMC;
 569                 sddp->dp.length   = sizeof(*sddp);
 570                 sddp->slot_number = dev->seq;
 571
 572                 return &sddp[1];
 573         }
 574 #endif
 575         case UCLASS_MASS_STORAGE:
 576         case UCLASS_USB_HUB: {
 577                 struct efi_device_path_usb_class *udp =
 578                         dp_fill(buf, dev->parent);
 579                 struct usb_device *udev = dev_get_parent_priv(dev);
 580                 struct usb_device_descriptor *desc = &udev->descriptor;
 581
 582                 udp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 583                 udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS;
 584                 udp->dp.length   = sizeof(*udp);
 585                 udp->vendor_id   = desc->idVendor;
 586                 udp->product_id  = desc->idProduct;
 587                 udp->device_class    = desc->bDeviceClass;
 588                 udp->device_subclass = desc->bDeviceSubClass;
 589                 udp->device_protocol = desc->bDeviceProtocol;
 590
 591                 return &udp[1];
 592         }
 593         default:
 594                 debug("%s(%u) %s: unhandled device class: %s (%u)\n",
 595                       __FILE__, __LINE__, __func__,
 596                       dev->name, dev->driver->id);
 597                 return dp_fill(buf, dev->parent);
 598         }
 599 }
 600
 601 /* Construct a device-path from a device: */
 602 struct efi_device_path *efi_dp_from_dev(struct udevice *dev)
 603 {
 604         void *buf, *start;
 605
 606         start = buf = dp_alloc(dp_size(dev) + sizeof(END));
 607         if (!buf)
 608                 return NULL;
 609         buf = dp_fill(buf, dev);
 610         *((struct efi_device_path *)buf) = END;
 611
 612         return start;
 613 }
 614 #endif
 615
 616 static unsigned dp_part_size(struct blk_desc *desc, int part)
 617 {
 618         unsigned dpsize;
 619
 620 #ifdef CONFIG_BLK
 621         {
 622                 struct udevice *dev;
 623                 int ret = blk_find_device(desc->if_type, desc->devnum, &dev);
 624
 625                 if (ret)
 626                         dev = desc->bdev->parent;
 627                 dpsize = dp_size(dev);
 628         }
 629 #else
 630         dpsize = sizeof(ROOT) + sizeof(struct efi_device_path_usb);
 631 #endif
 632
 633         if (part == 0) /* the actual disk, not a partition */
 634                 return dpsize;
 635
 636         if (desc->part_type == PART_TYPE_ISO)
 637                 dpsize += sizeof(struct efi_device_path_cdrom_path);
 638         else
 639                 dpsize += sizeof(struct efi_device_path_hard_drive_path);
 640
 641         return dpsize;
 642 }
 643
 644 /*
 645  * Create a device node for a block device partition.
 646  *
 647  * @buf         buffer to which the device path is wirtten
 648  * @desc        block device descriptor
 649  * @part        partition number, 0 identifies a block device
 650  */
 651 static void *dp_part_node(void *buf, struct blk_desc *desc, int part)
 652 {
 653         disk_partition_t info;
 654
 655         part_get_info(desc, part, &info);
 656
 657         if (desc->part_type == PART_TYPE_ISO) {
 658                 struct efi_device_path_cdrom_path *cddp = buf;
 659
 660                 cddp->boot_entry = part;
 661                 cddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 662                 cddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_CDROM_PATH;
 663                 cddp->dp.length = sizeof(*cddp);
 664                 cddp->partition_start = info.start;
 665                 cddp->partition_end = info.size;
 666
 667                 buf = &cddp[1];
 668         } else {
 669                 struct efi_device_path_hard_drive_path *hddp = buf;
 670
 671                 hddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 672                 hddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH;
 673                 hddp->dp.length = sizeof(*hddp);
 674                 hddp->partition_number = part;
 675                 hddp->partition_start = info.start;
 676                 hddp->partition_end = info.size;
 677                 if (desc->part_type == PART_TYPE_EFI)
 678                         hddp->partmap_type = 2;
 679                 else
 680                         hddp->partmap_type = 1;
 681
 682                 switch (desc->sig_type) {
 683                 case SIG_TYPE_NONE:
 684                 default:
 685                         hddp->signature_type = 0;
 686                         memset(hddp->partition_signature, 0,
 687                                sizeof(hddp->partition_signature));
 688                         break;
 689                 case SIG_TYPE_MBR:
 690                         hddp->signature_type = 1;
 691                         memset(hddp->partition_signature, 0,
 692                                sizeof(hddp->partition_signature));
 693                         memcpy(hddp->partition_signature, &desc->mbr_sig,
 694                                sizeof(desc->mbr_sig));
 695                         break;
 696                 case SIG_TYPE_GUID:
 697                         hddp->signature_type = 2;
 698                         memcpy(hddp->partition_signature, &desc->guid_sig,
 699                                sizeof(hddp->partition_signature));
 700                         break;
 701                 }
 702
 703                 buf = &hddp[1];
 704         }
 705
 706         return buf;
 707 }
 708
 709 /*
 710  * Create a device path for a block device or one of its partitions.
 711  *
 712  * @buf         buffer to which the device path is wirtten
 713  * @desc        block device descriptor
 714  * @part        partition number, 0 identifies a block device
 715  */
 716 static void *dp_part_fill(void *buf, struct blk_desc *desc, int part)
 717 {
 718 #ifdef CONFIG_BLK
 719         {
 720                 struct udevice *dev;
 721                 int ret = blk_find_device(desc->if_type, desc->devnum, &dev);
 722
 723                 if (ret)
 724                         dev = desc->bdev->parent;
 725                 buf = dp_fill(buf, dev);
 726         }
 727 #else
 728         /*
 729          * We *could* make a more accurate path, by looking at if_type
 730          * and handling all the different cases like we do for non-
 731          * legacy (ie CONFIG_BLK=y) case.  But most important thing
 732          * is just to have a unique device-path for if_type+devnum.
 733          * So map things to a fictitious USB device.
 734          */
 735         struct efi_device_path_usb *udp;
 736
 737         memcpy(buf, &ROOT, sizeof(ROOT));
 738         buf += sizeof(ROOT);
 739
 740         udp = buf;
 741         udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 742         udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB;
 743         udp->dp.length = sizeof(*udp);
 744         udp->parent_port_number = desc->if_type;
 745         udp->usb_interface = desc->devnum;
 746         buf = &udp[1];
 747 #endif
 748
 749         if (part == 0) /* the actual disk, not a partition */
 750                 return buf;
 751
 752         return dp_part_node(buf, desc, part);
 753 }
 754
 755 /* Construct a device-path from a partition on a blk device: */
 756 struct efi_device_path *efi_dp_from_part(struct blk_desc *desc, int part)
 757 {
 758         void *buf, *start;
 759
 760         start = buf = dp_alloc(dp_part_size(desc, part) + sizeof(END));
 761         if (!buf)
 762                 return NULL;
 763
 764         buf = dp_part_fill(buf, desc, part);
 765
 766         *((struct efi_device_path *)buf) = END;
 767
 768         return start;
 769 }
 770
 771 /*
 772  * Create a device node for a block device partition.
 773  *
 774  * @buf         buffer to which the device path is wirtten
 775  * @desc        block device descriptor
 776  * @part        partition number, 0 identifies a block device
 777  */
 778 struct efi_device_path *efi_dp_part_node(struct blk_desc *desc, int part)
 779 {
 780         efi_uintn_t dpsize;
 781         void *buf;
 782
 783         if (desc->part_type == PART_TYPE_ISO)
 784                 dpsize = sizeof(struct efi_device_path_cdrom_path);
 785         else
 786                 dpsize = sizeof(struct efi_device_path_hard_drive_path);
 787         buf = dp_alloc(dpsize);
 788
 789         dp_part_node(buf, desc, part);
 790
 791         return buf;
 792 }
 793
 794 /* convert path to an UEFI style path (ie. DOS style backslashes and utf16) */
 795 static void path_to_uefi(u16 *uefi, const char *path)
 796 {
 797         while (*path) {
 798                 char c = *(path++);
 799                 if (c == '/')
 800                         c = '\\';
 801                 *(uefi++) = c;
 802         }
 803         *uefi = '\0';
 804 }
 805
 806 /*
 807  * If desc is NULL, this creates a path with only the file component,
 808  * otherwise it creates a full path with both device and file components
 809  */
 810 struct efi_device_path *efi_dp_from_file(struct blk_desc *desc, int part,
 811                 const char *path)
 812 {
 813         struct efi_device_path_file_path *fp;
 814         void *buf, *start;
 815         unsigned dpsize = 0, fpsize;
 816
 817         if (desc)
 818                 dpsize = dp_part_size(desc, part);
 819
 820         fpsize = sizeof(struct efi_device_path) + 2 * (strlen(path) + 1);
 821         dpsize += fpsize;
 822
 823         start = buf = dp_alloc(dpsize + sizeof(END));
 824         if (!buf)
 825                 return NULL;
 826
 827         if (desc)
 828                 buf = dp_part_fill(buf, desc, part);
 829
 830         /* add file-path: */
 831         fp = buf;
 832         fp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 833         fp->dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
 834         fp->dp.length = fpsize;
 835         path_to_uefi(fp->str, path);
 836         buf += fpsize;
 837
 838         *((struct efi_device_path *)buf) = END;
 839
 840         return start;
 841 }
 842
 843 #ifdef CONFIG_NET
 844 struct efi_device_path *efi_dp_from_eth(void)
 845 {
 846 #ifndef CONFIG_DM_ETH
 847         struct efi_device_path_mac_addr *ndp;
 848 #endif
 849         void *buf, *start;
 850         unsigned dpsize = 0;
 851
 852         assert(eth_get_dev());
 853
 854 #ifdef CONFIG_DM_ETH
 855         dpsize += dp_size(eth_get_dev());
 856 #else
 857         dpsize += sizeof(ROOT);
 858         dpsize += sizeof(*ndp);
 859 #endif
 860
 861         start = buf = dp_alloc(dpsize + sizeof(END));
 862         if (!buf)
 863                 return NULL;
 864
 865 #ifdef CONFIG_DM_ETH
 866         buf = dp_fill(buf, eth_get_dev());
 867 #else
 868         memcpy(buf, &ROOT, sizeof(ROOT));
 869         buf += sizeof(ROOT);
 870
 871         ndp = buf;
 872         ndp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 873         ndp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
 874         ndp->dp.length = sizeof(*ndp);
 875         ndp->if_type = 1; /* Ethernet */
 876         memcpy(ndp->mac.addr, eth_get_ethaddr(), ARP_HLEN);
 877         buf = &ndp[1];
 878 #endif
 879
 880         *((struct efi_device_path *)buf) = END;
 881
 882         return start;
 883 }
 884 #endif
 885
 886 /* Construct a device-path for memory-mapped image */
 887 struct efi_device_path *efi_dp_from_mem(uint32_t memory_type,
 888                                         uint64_t start_address,
 889                                         uint64_t end_address)
 890 {
 891         struct efi_device_path_memory *mdp;
 892         void *buf, *start;
 893
 894         start = buf = dp_alloc(sizeof(*mdp) + sizeof(END));
 895         if (!buf)
 896                 return NULL;
 897
 898         mdp = buf;
 899         mdp->dp.type = DEVICE_PATH_TYPE_HARDWARE_DEVICE;
 900         mdp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MEMORY;
 901         mdp->dp.length = sizeof(*mdp);
 902         mdp->memory_type = memory_type;
 903         mdp->start_address = start_address;
 904         mdp->end_address = end_address;
 905         buf = &mdp[1];
 906
 907         *((struct efi_device_path *)buf) = END;
 908
 909         return start;
 910 }
 911
 912 /*
 913  * Helper to split a full device path (containing both device and file
 914  * parts) into it's constituent parts.
 915  */
 916 efi_status_t efi_dp_split_file_path(struct efi_device_path *full_path,
 917                                     struct efi_device_path **device_path,
 918                                     struct efi_device_path **file_path)
 919 {
 920         struct efi_device_path *p, *dp, *fp;
 921
 922         *device_path = NULL;
 923         *file_path = NULL;
 924         dp = efi_dp_dup(full_path);
 925         if (!dp)
 926                 return EFI_OUT_OF_RESOURCES;
 927         p = dp;
 928         while (!EFI_DP_TYPE(p, MEDIA_DEVICE, FILE_PATH)) {
 929                 p = efi_dp_next(p);
 930                 if (!p)
 931                         return EFI_OUT_OF_RESOURCES;
 932         }
 933         fp = efi_dp_dup(p);
 934         if (!fp)
 935                 return EFI_OUT_OF_RESOURCES;
 936         p->type = DEVICE_PATH_TYPE_END;
 937         p->sub_type = DEVICE_PATH_SUB_TYPE_END;
 938         p->length = sizeof(*p);
 939
 940         *device_path = dp;
 941         *file_path = fp;
 942         return EFI_SUCCESS;
 943 }