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  * We can have device paths that start with a USB WWID or a USB Class node,
 113  * and a few other cases which don't encode the full device path with bus
 114  * hierarchy:
 115  *
 116  *   - MESSAGING:USB_WWID
 117  *   - MESSAGING:USB_CLASS
 118  *   - MEDIA:FILE_PATH
 119  *   - MEDIA:HARD_DRIVE
 120  *   - MESSAGING:URI
 121  *
 122  * See UEFI spec (section 3.1.2, about short-form device-paths)
 123  */
 124 static struct efi_device_path *shorten_path(struct efi_device_path *dp)
 125 {
 126         while (dp) {
 127                 /*
 128                  * TODO: Add MESSAGING:USB_WWID and MESSAGING:URI..
 129                  * in practice fallback.efi just uses MEDIA:HARD_DRIVE
 130                  * so not sure when we would see these other cases.
 131                  */
 132                 if (EFI_DP_TYPE(dp, MESSAGING_DEVICE, MSG_USB_CLASS) ||
 133                     EFI_DP_TYPE(dp, MEDIA_DEVICE, HARD_DRIVE_PATH) ||
 134                     EFI_DP_TYPE(dp, MEDIA_DEVICE, FILE_PATH))
 135                         return dp;
 136
 137                 dp = efi_dp_next(dp);
 138         }
 139
 140         return dp;
 141 }
 142
 143 static struct efi_object *find_obj(struct efi_device_path *dp, bool short_path,
 144                                    struct efi_device_path **rem)
 145 {
 146         struct efi_object *efiobj;
 147         efi_uintn_t dp_size = efi_dp_instance_size(dp);
 148
 149         list_for_each_entry(efiobj, &efi_obj_list, link) {
 150                 struct efi_handler *handler;
 151                 struct efi_device_path *obj_dp;
 152                 efi_status_t ret;
 153
 154                 ret = efi_search_protocol(efiobj,
 155                                           &efi_guid_device_path, &handler);
 156                 if (ret != EFI_SUCCESS)
 157                         continue;
 158                 obj_dp = handler->protocol_interface;
 159
 160                 do {
 161                         if (efi_dp_match(dp, obj_dp) == 0) {
 162                                 if (rem) {
 163                                         /*
 164                                          * Allow partial matches, but inform
 165                                          * the caller.
 166                                          */
 167                                         *rem = ((void *)dp) +
 168                                                 efi_dp_instance_size(obj_dp);
 169                                         return efiobj;
 170                                 } else {
 171                                         /* Only return on exact matches */
 172                                         if (efi_dp_instance_size(obj_dp) ==
 173                                             dp_size)
 174                                                 return efiobj;
 175                                 }
 176                         }
 177
 178                         obj_dp = shorten_path(efi_dp_next(obj_dp));
 179                 } while (short_path && obj_dp);
 180         }
 181
 182         return NULL;
 183 }
 184
 185 /*
 186  * Find an efiobj from device-path, if 'rem' is not NULL, returns the
 187  * remaining part of the device path after the matched object.
 188  */
 189 struct efi_object *efi_dp_find_obj(struct efi_device_path *dp,
 190                                    struct efi_device_path **rem)
 191 {
 192         struct efi_object *efiobj;
 193
 194         /* Search for an exact match first */
 195         efiobj = find_obj(dp, false, NULL);
 196
 197         /* Then for a fuzzy match */
 198         if (!efiobj)
 199                 efiobj = find_obj(dp, false, rem);
 200
 201         /* And now for a fuzzy short match */
 202         if (!efiobj)
 203                 efiobj = find_obj(dp, true, rem);
 204
 205         return efiobj;
 206 }
 207
 208 /*
 209  * Determine the last device path node that is not the end node.
 210  *
 211  * @dp          device path
 212  * @return      last node before the end node if it exists
 213  *              otherwise NULL
 214  */
 215 const struct efi_device_path *efi_dp_last_node(const struct efi_device_path *dp)
 216 {
 217         struct efi_device_path *ret;
 218
 219         if (!dp || dp->type == DEVICE_PATH_TYPE_END)
 220                 return NULL;
 221         while (dp) {
 222                 ret = (struct efi_device_path *)dp;
 223                 dp = efi_dp_next(dp);
 224         }
 225         return ret;
 226 }
 227
 228 /* get size of the first device path instance excluding end node */
 229 efi_uintn_t efi_dp_instance_size(const struct efi_device_path *dp)
 230 {
 231         efi_uintn_t sz = 0;
 232
 233         if (!dp || dp->type == DEVICE_PATH_TYPE_END)
 234                 return 0;
 235         while (dp) {
 236                 sz += dp->length;
 237                 dp = efi_dp_next(dp);
 238         }
 239
 240         return sz;
 241 }
 242
 243 /* get size of multi-instance device path excluding end node */
 244 efi_uintn_t efi_dp_size(const struct efi_device_path *dp)
 245 {
 246         const struct efi_device_path *p = dp;
 247
 248         if (!p)
 249                 return 0;
 250         while (p->type != DEVICE_PATH_TYPE_END ||
 251                p->sub_type != DEVICE_PATH_SUB_TYPE_END)
 252                 p = (void *)p + p->length;
 253
 254         return (void *)p - (void *)dp;
 255 }
 256
 257 /* copy multi-instance device path */
 258 struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp)
 259 {
 260         struct efi_device_path *ndp;
 261         size_t sz = efi_dp_size(dp) + sizeof(END);
 262
 263         if (!dp)
 264                 return NULL;
 265
 266         ndp = dp_alloc(sz);
 267         if (!ndp)
 268                 return NULL;
 269         memcpy(ndp, dp, sz);
 270
 271         return ndp;
 272 }
 273
 274 struct efi_device_path *efi_dp_append(const struct efi_device_path *dp1,
 275                                       const struct efi_device_path *dp2)
 276 {
 277         struct efi_device_path *ret;
 278
 279         if (!dp1 && !dp2) {
 280                 /* return an end node */
 281                 ret = efi_dp_dup(&END);
 282         } else if (!dp1) {
 283                 ret = efi_dp_dup(dp2);
 284         } else if (!dp2) {
 285                 ret = efi_dp_dup(dp1);
 286         } else {
 287                 /* both dp1 and dp2 are non-null */
 288                 unsigned sz1 = efi_dp_size(dp1);
 289                 unsigned sz2 = efi_dp_size(dp2);
 290                 void *p = dp_alloc(sz1 + sz2 + sizeof(END));
 291                 if (!p)
 292                         return NULL;
 293                 memcpy(p, dp1, sz1);
 294                 /* the end node of the second device path has to be retained */
 295                 memcpy(p + sz1, dp2, sz2 + sizeof(END));
 296                 ret = p;
 297         }
 298
 299         return ret;
 300 }
 301
 302 struct efi_device_path *efi_dp_append_node(const struct efi_device_path *dp,
 303                                            const struct efi_device_path *node)
 304 {
 305         struct efi_device_path *ret;
 306
 307         if (!node && !dp) {
 308                 ret = efi_dp_dup(&END);
 309         } else if (!node) {
 310                 ret = efi_dp_dup(dp);
 311         } else if (!dp) {
 312                 size_t sz = node->length;
 313                 void *p = dp_alloc(sz + sizeof(END));
 314                 if (!p)
 315                         return NULL;
 316                 memcpy(p, node, sz);
 317                 memcpy(p + sz, &END, sizeof(END));
 318                 ret = p;
 319         } else {
 320                 /* both dp and node are non-null */
 321                 size_t sz = efi_dp_size(dp);
 322                 void *p = dp_alloc(sz + node->length + sizeof(END));
 323                 if (!p)
 324                         return NULL;
 325                 memcpy(p, dp, sz);
 326                 memcpy(p + sz, node, node->length);
 327                 memcpy(p + sz + node->length, &END, sizeof(END));
 328                 ret = p;
 329         }
 330
 331         return ret;
 332 }
 333
 334 struct efi_device_path *efi_dp_create_device_node(const u8 type,
 335                                                   const u8 sub_type,
 336                                                   const u16 length)
 337 {
 338         struct efi_device_path *ret;
 339
 340         ret = dp_alloc(length);
 341         if (!ret)
 342                 return ret;
 343         ret->type = type;
 344         ret->sub_type = sub_type;
 345         ret->length = length;
 346         return ret;
 347 }
 348
 349 struct efi_device_path *efi_dp_append_instance(
 350                 const struct efi_device_path *dp,
 351                 const struct efi_device_path *dpi)
 352 {
 353         size_t sz, szi;
 354         struct efi_device_path *p, *ret;
 355
 356         if (!dpi)
 357                 return NULL;
 358         if (!dp)
 359                 return efi_dp_dup(dpi);
 360         sz = efi_dp_size(dp);
 361         szi = efi_dp_instance_size(dpi);
 362         p = dp_alloc(sz + szi + 2 * sizeof(END));
 363         if (!p)
 364                 return NULL;
 365         ret = p;
 366         memcpy(p, dp, sz + sizeof(END));
 367         p = (void *)p + sz;
 368         p->sub_type = DEVICE_PATH_SUB_TYPE_INSTANCE_END;
 369         p = (void *)p + sizeof(END);
 370         memcpy(p, dpi, szi);
 371         p = (void *)p + szi;
 372         memcpy(p, &END, sizeof(END));
 373         return ret;
 374 }
 375
 376 struct efi_device_path *efi_dp_get_next_instance(struct efi_device_path **dp,
 377                                                  efi_uintn_t *size)
 378 {
 379         size_t sz;
 380         struct efi_device_path *p;
 381
 382         if (size)
 383                 *size = 0;
 384         if (!dp || !*dp)
 385                 return NULL;
 386         sz = efi_dp_instance_size(*dp);
 387         p = dp_alloc(sz + sizeof(END));
 388         if (!p)
 389                 return NULL;
 390         memcpy(p, *dp, sz + sizeof(END));
 391         *dp = (void *)*dp + sz;
 392         if ((*dp)->sub_type == DEVICE_PATH_SUB_TYPE_INSTANCE_END)
 393                 *dp = (void *)*dp + sizeof(END);
 394         else
 395                 *dp = NULL;
 396         if (size)
 397                 *size = sz + sizeof(END);
 398         return p;
 399 }
 400
 401 bool efi_dp_is_multi_instance(const struct efi_device_path *dp)
 402 {
 403         const struct efi_device_path *p = dp;
 404
 405         if (!p)
 406                 return false;
 407         while (p->type != DEVICE_PATH_TYPE_END)
 408                 p = (void *)p + p->length;
 409         return p->sub_type == DEVICE_PATH_SUB_TYPE_INSTANCE_END;
 410 }
 411
 412 #ifdef CONFIG_DM
 413 /* size of device-path not including END node for device and all parents
 414  * up to the root device.
 415  */
 416 static unsigned dp_size(struct udevice *dev)
 417 {
 418         if (!dev || !dev->driver)
 419                 return sizeof(ROOT);
 420
 421         switch (dev->driver->id) {
 422         case UCLASS_ROOT:
 423         case UCLASS_SIMPLE_BUS:
 424                 /* stop traversing parents at this point: */
 425                 return sizeof(ROOT);
 426         case UCLASS_ETH:
 427                 return dp_size(dev->parent) +
 428                         sizeof(struct efi_device_path_mac_addr);
 429 #ifdef CONFIG_BLK
 430         case UCLASS_BLK:
 431                 switch (dev->parent->uclass->uc_drv->id) {
 432 #ifdef CONFIG_IDE
 433                 case UCLASS_IDE:
 434                         return dp_size(dev->parent) +
 435                                 sizeof(struct efi_device_path_atapi);
 436 #endif
 437 #if defined(CONFIG_SCSI) && defined(CONFIG_DM_SCSI)
 438                 case UCLASS_SCSI:
 439                         return dp_size(dev->parent) +
 440                                 sizeof(struct efi_device_path_scsi);
 441 #endif
 442 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 443                 case UCLASS_MMC:
 444                         return dp_size(dev->parent) +
 445                                 sizeof(struct efi_device_path_sd_mmc_path);
 446 #endif
 447                 default:
 448                         return dp_size(dev->parent);
 449                 }
 450 #endif
 451 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 452         case UCLASS_MMC:
 453                 return dp_size(dev->parent) +
 454                         sizeof(struct efi_device_path_sd_mmc_path);
 455 #endif
 456         case UCLASS_MASS_STORAGE:
 457         case UCLASS_USB_HUB:
 458                 return dp_size(dev->parent) +
 459                         sizeof(struct efi_device_path_usb_class);
 460         default:
 461                 /* just skip over unknown classes: */
 462                 return dp_size(dev->parent);
 463         }
 464 }
 465
 466 /*
 467  * Recursively build a device path.
 468  *
 469  * @buf         pointer to the end of the device path
 470  * @dev         device
 471  * @return      pointer to the end of the device path
 472  */
 473 static void *dp_fill(void *buf, struct udevice *dev)
 474 {
 475         if (!dev || !dev->driver)
 476                 return buf;
 477
 478         switch (dev->driver->id) {
 479         case UCLASS_ROOT:
 480         case UCLASS_SIMPLE_BUS: {
 481                 /* stop traversing parents at this point: */
 482                 struct efi_device_path_vendor *vdp = buf;
 483                 *vdp = ROOT;
 484                 return &vdp[1];
 485         }
 486 #ifdef CONFIG_DM_ETH
 487         case UCLASS_ETH: {
 488                 struct efi_device_path_mac_addr *dp =
 489                         dp_fill(buf, dev->parent);
 490                 struct eth_pdata *pdata = dev->platdata;
 491
 492                 dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 493                 dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
 494                 dp->dp.length = sizeof(*dp);
 495                 memset(&dp->mac, 0, sizeof(dp->mac));
 496                 /* We only support IPv4 */
 497                 memcpy(&dp->mac, &pdata->enetaddr, ARP_HLEN);
 498                 /* Ethernet */
 499                 dp->if_type = 1;
 500                 return &dp[1];
 501         }
 502 #endif
 503 #ifdef CONFIG_BLK
 504         case UCLASS_BLK:
 505                 switch (dev->parent->uclass->uc_drv->id) {
 506 #ifdef CONFIG_IDE
 507                 case UCLASS_IDE: {
 508                         struct efi_device_path_atapi *dp =
 509                         dp_fill(buf, dev->parent);
 510                         struct blk_desc *desc = dev_get_uclass_platdata(dev);
 511
 512                         dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 513                         dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_ATAPI;
 514                         dp->dp.length = sizeof(*dp);
 515                         dp->logical_unit_number = desc->devnum;
 516                         dp->primary_secondary = IDE_BUS(desc->devnum);
 517                         dp->slave_master = desc->devnum %
 518                                 (CONFIG_SYS_IDE_MAXDEVICE /
 519                                  CONFIG_SYS_IDE_MAXBUS);
 520                         return &dp[1];
 521                         }
 522 #endif
 523 #if defined(CONFIG_SCSI) && defined(CONFIG_DM_SCSI)
 524                 case UCLASS_SCSI: {
 525                         struct efi_device_path_scsi *dp =
 526                                 dp_fill(buf, dev->parent);
 527                         struct blk_desc *desc = dev_get_uclass_platdata(dev);
 528
 529                         dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 530                         dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_SCSI;
 531                         dp->dp.length = sizeof(*dp);
 532                         dp->logical_unit_number = desc->lun;
 533                         dp->target_id = desc->target;
 534                         return &dp[1];
 535                         }
 536 #endif
 537 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 538                 case UCLASS_MMC: {
 539                         struct efi_device_path_sd_mmc_path *sddp =
 540                                 dp_fill(buf, dev->parent);
 541                         struct blk_desc *desc = dev_get_uclass_platdata(dev);
 542
 543                         sddp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 544                         sddp->dp.sub_type = is_sd(desc) ?
 545                                 DEVICE_PATH_SUB_TYPE_MSG_SD :
 546                                 DEVICE_PATH_SUB_TYPE_MSG_MMC;
 547                         sddp->dp.length   = sizeof(*sddp);
 548                         sddp->slot_number = dev->seq;
 549                         return &sddp[1];
 550                         }
 551 #endif
 552                 default:
 553                         debug("%s(%u) %s: unhandled parent class: %s (%u)\n",
 554                               __FILE__, __LINE__, __func__,
 555                               dev->name, dev->parent->uclass->uc_drv->id);
 556                         return dp_fill(buf, dev->parent);
 557                 }
 558 #endif
 559 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 560         case UCLASS_MMC: {
 561                 struct efi_device_path_sd_mmc_path *sddp =
 562                         dp_fill(buf, dev->parent);
 563                 struct mmc *mmc = mmc_get_mmc_dev(dev);
 564                 struct blk_desc *desc = mmc_get_blk_desc(mmc);
 565
 566                 sddp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 567                 sddp->dp.sub_type = is_sd(desc) ?
 568                         DEVICE_PATH_SUB_TYPE_MSG_SD :
 569                         DEVICE_PATH_SUB_TYPE_MSG_MMC;
 570                 sddp->dp.length   = sizeof(*sddp);
 571                 sddp->slot_number = dev->seq;
 572
 573                 return &sddp[1];
 574         }
 575 #endif
 576         case UCLASS_MASS_STORAGE:
 577         case UCLASS_USB_HUB: {
 578                 struct efi_device_path_usb_class *udp =
 579                         dp_fill(buf, dev->parent);
 580                 struct usb_device *udev = dev_get_parent_priv(dev);
 581                 struct usb_device_descriptor *desc = &udev->descriptor;
 582
 583                 udp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 584                 udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS;
 585                 udp->dp.length   = sizeof(*udp);
 586                 udp->vendor_id   = desc->idVendor;
 587                 udp->product_id  = desc->idProduct;
 588                 udp->device_class    = desc->bDeviceClass;
 589                 udp->device_subclass = desc->bDeviceSubClass;
 590                 udp->device_protocol = desc->bDeviceProtocol;
 591
 592                 return &udp[1];
 593         }
 594         default:
 595                 debug("%s(%u) %s: unhandled device class: %s (%u)\n",
 596                       __FILE__, __LINE__, __func__,
 597                       dev->name, dev->driver->id);
 598                 return dp_fill(buf, dev->parent);
 599         }
 600 }
 601
 602 /* Construct a device-path from a device: */
 603 struct efi_device_path *efi_dp_from_dev(struct udevice *dev)
 604 {
 605         void *buf, *start;
 606
 607         start = buf = dp_alloc(dp_size(dev) + sizeof(END));
 608         if (!buf)
 609                 return NULL;
 610         buf = dp_fill(buf, dev);
 611         *((struct efi_device_path *)buf) = END;
 612
 613         return start;
 614 }
 615 #endif
 616
 617 static unsigned dp_part_size(struct blk_desc *desc, int part)
 618 {
 619         unsigned dpsize;
 620
 621 #ifdef CONFIG_BLK
 622         {
 623                 struct udevice *dev;
 624                 int ret = blk_find_device(desc->if_type, desc->devnum, &dev);
 625
 626                 if (ret)
 627                         dev = desc->bdev->parent;
 628                 dpsize = dp_size(dev);
 629         }
 630 #else
 631         dpsize = sizeof(ROOT) + sizeof(struct efi_device_path_usb);
 632 #endif
 633
 634         if (part == 0) /* the actual disk, not a partition */
 635                 return dpsize;
 636
 637         if (desc->part_type == PART_TYPE_ISO)
 638                 dpsize += sizeof(struct efi_device_path_cdrom_path);
 639         else
 640                 dpsize += sizeof(struct efi_device_path_hard_drive_path);
 641
 642         return dpsize;
 643 }
 644
 645 /*
 646  * Create a device node for a block device partition.
 647  *
 648  * @buf         buffer to which the device path is written
 649  * @desc        block device descriptor
 650  * @part        partition number, 0 identifies a block device
 651  */
 652 static void *dp_part_node(void *buf, struct blk_desc *desc, int part)
 653 {
 654         disk_partition_t info;
 655
 656         part_get_info(desc, part, &info);
 657
 658         if (desc->part_type == PART_TYPE_ISO) {
 659                 struct efi_device_path_cdrom_path *cddp = buf;
 660
 661                 cddp->boot_entry = part;
 662                 cddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 663                 cddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_CDROM_PATH;
 664                 cddp->dp.length = sizeof(*cddp);
 665                 cddp->partition_start = info.start;
 666                 cddp->partition_end = info.size;
 667
 668                 buf = &cddp[1];
 669         } else {
 670                 struct efi_device_path_hard_drive_path *hddp = buf;
 671
 672                 hddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 673                 hddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH;
 674                 hddp->dp.length = sizeof(*hddp);
 675                 hddp->partition_number = part;
 676                 hddp->partition_start = info.start;
 677                 hddp->partition_end = info.size;
 678                 if (desc->part_type == PART_TYPE_EFI)
 679                         hddp->partmap_type = 2;
 680                 else
 681                         hddp->partmap_type = 1;
 682
 683                 switch (desc->sig_type) {
 684                 case SIG_TYPE_NONE:
 685                 default:
 686                         hddp->signature_type = 0;
 687                         memset(hddp->partition_signature, 0,
 688                                sizeof(hddp->partition_signature));
 689                         break;
 690                 case SIG_TYPE_MBR:
 691                         hddp->signature_type = 1;
 692                         memset(hddp->partition_signature, 0,
 693                                sizeof(hddp->partition_signature));
 694                         memcpy(hddp->partition_signature, &desc->mbr_sig,
 695                                sizeof(desc->mbr_sig));
 696                         break;
 697                 case SIG_TYPE_GUID:
 698                         hddp->signature_type = 2;
 699                         memcpy(hddp->partition_signature, &desc->guid_sig,
 700                                sizeof(hddp->partition_signature));
 701                         break;
 702                 }
 703
 704                 buf = &hddp[1];
 705         }
 706
 707         return buf;
 708 }
 709
 710 /*
 711  * Create a device path for a block device or one of its partitions.
 712  *
 713  * @buf         buffer to which the device path is written
 714  * @desc        block device descriptor
 715  * @part        partition number, 0 identifies a block device
 716  */
 717 static void *dp_part_fill(void *buf, struct blk_desc *desc, int part)
 718 {
 719 #ifdef CONFIG_BLK
 720         {
 721                 struct udevice *dev;
 722                 int ret = blk_find_device(desc->if_type, desc->devnum, &dev);
 723
 724                 if (ret)
 725                         dev = desc->bdev->parent;
 726                 buf = dp_fill(buf, dev);
 727         }
 728 #else
 729         /*
 730          * We *could* make a more accurate path, by looking at if_type
 731          * and handling all the different cases like we do for non-
 732          * legacy (i.e. CONFIG_BLK=y) case. But most important thing
 733          * is just to have a unique device-path for if_type+devnum.
 734          * So map things to a fictitious USB device.
 735          */
 736         struct efi_device_path_usb *udp;
 737
 738         memcpy(buf, &ROOT, sizeof(ROOT));
 739         buf += sizeof(ROOT);
 740
 741         udp = buf;
 742         udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 743         udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB;
 744         udp->dp.length = sizeof(*udp);
 745         udp->parent_port_number = desc->if_type;
 746         udp->usb_interface = desc->devnum;
 747         buf = &udp[1];
 748 #endif
 749
 750         if (part == 0) /* the actual disk, not a partition */
 751                 return buf;
 752
 753         return dp_part_node(buf, desc, part);
 754 }
 755
 756 /* Construct a device-path from a partition on a block device: */
 757 struct efi_device_path *efi_dp_from_part(struct blk_desc *desc, int part)
 758 {
 759         void *buf, *start;
 760
 761         start = buf = dp_alloc(dp_part_size(desc, part) + sizeof(END));
 762         if (!buf)
 763                 return NULL;
 764
 765         buf = dp_part_fill(buf, desc, part);
 766
 767         *((struct efi_device_path *)buf) = END;
 768
 769         return start;
 770 }
 771
 772 /*
 773  * Create a device node for a block device partition.
 774  *
 775  * @buf         buffer to which the device path is written
 776  * @desc        block device descriptor
 777  * @part        partition number, 0 identifies a block device
 778  */
 779 struct efi_device_path *efi_dp_part_node(struct blk_desc *desc, int part)
 780 {
 781         efi_uintn_t dpsize;
 782         void *buf;
 783
 784         if (desc->part_type == PART_TYPE_ISO)
 785                 dpsize = sizeof(struct efi_device_path_cdrom_path);
 786         else
 787                 dpsize = sizeof(struct efi_device_path_hard_drive_path);
 788         buf = dp_alloc(dpsize);
 789
 790         dp_part_node(buf, desc, part);
 791
 792         return buf;
 793 }
 794
 795 /* convert path to an UEFI style path (i.e. DOS style backslashes and UTF-16) */
 796 static void path_to_uefi(u16 *uefi, const char *path)
 797 {
 798         while (*path) {
 799                 char c = *(path++);
 800                 if (c == '/')
 801                         c = '\\';
 802                 *(uefi++) = c;
 803         }
 804         *uefi = '\0';
 805 }
 806
 807 /*
 808  * If desc is NULL, this creates a path with only the file component,
 809  * otherwise it creates a full path with both device and file components
 810  */
 811 struct efi_device_path *efi_dp_from_file(struct blk_desc *desc, int part,
 812                 const char *path)
 813 {
 814         struct efi_device_path_file_path *fp;
 815         void *buf, *start;
 816         unsigned dpsize = 0, fpsize;
 817
 818         if (desc)
 819                 dpsize = dp_part_size(desc, part);
 820
 821         fpsize = sizeof(struct efi_device_path) + 2 * (strlen(path) + 1);
 822         dpsize += fpsize;
 823
 824         start = buf = dp_alloc(dpsize + sizeof(END));
 825         if (!buf)
 826                 return NULL;
 827
 828         if (desc)
 829                 buf = dp_part_fill(buf, desc, part);
 830
 831         /* add file-path: */
 832         fp = buf;
 833         fp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 834         fp->dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
 835         fp->dp.length = fpsize;
 836         path_to_uefi(fp->str, path);
 837         buf += fpsize;
 838
 839         *((struct efi_device_path *)buf) = END;
 840
 841         return start;
 842 }
 843
 844 #ifdef CONFIG_NET
 845 struct efi_device_path *efi_dp_from_eth(void)
 846 {
 847 #ifndef CONFIG_DM_ETH
 848         struct efi_device_path_mac_addr *ndp;
 849 #endif
 850         void *buf, *start;
 851         unsigned dpsize = 0;
 852
 853         assert(eth_get_dev());
 854
 855 #ifdef CONFIG_DM_ETH
 856         dpsize += dp_size(eth_get_dev());
 857 #else
 858         dpsize += sizeof(ROOT);
 859         dpsize += sizeof(*ndp);
 860 #endif
 861
 862         start = buf = dp_alloc(dpsize + sizeof(END));
 863         if (!buf)
 864                 return NULL;
 865
 866 #ifdef CONFIG_DM_ETH
 867         buf = dp_fill(buf, eth_get_dev());
 868 #else
 869         memcpy(buf, &ROOT, sizeof(ROOT));
 870         buf += sizeof(ROOT);
 871
 872         ndp = buf;
 873         ndp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 874         ndp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
 875         ndp->dp.length = sizeof(*ndp);
 876         ndp->if_type = 1; /* Ethernet */
 877         memcpy(ndp->mac.addr, eth_get_ethaddr(), ARP_HLEN);
 878         buf = &ndp[1];
 879 #endif
 880
 881         *((struct efi_device_path *)buf) = END;
 882
 883         return start;
 884 }
 885 #endif
 886
 887 /* Construct a device-path for memory-mapped image */
 888 struct efi_device_path *efi_dp_from_mem(uint32_t memory_type,
 889                                         uint64_t start_address,
 890                                         uint64_t end_address)
 891 {
 892         struct efi_device_path_memory *mdp;
 893         void *buf, *start;
 894
 895         start = buf = dp_alloc(sizeof(*mdp) + sizeof(END));
 896         if (!buf)
 897                 return NULL;
 898
 899         mdp = buf;
 900         mdp->dp.type = DEVICE_PATH_TYPE_HARDWARE_DEVICE;
 901         mdp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MEMORY;
 902         mdp->dp.length = sizeof(*mdp);
 903         mdp->memory_type = memory_type;
 904         mdp->start_address = start_address;
 905         mdp->end_address = end_address;
 906         buf = &mdp[1];
 907
 908         *((struct efi_device_path *)buf) = END;
 909
 910         return start;
 911 }
 912
 913 /*
 914  * Helper to split a full device path (containing both device and file
 915  * parts) into it's constituent parts.
 916  */
 917 efi_status_t efi_dp_split_file_path(struct efi_device_path *full_path,
 918                                     struct efi_device_path **device_path,
 919                                     struct efi_device_path **file_path)
 920 {
 921         struct efi_device_path *p, *dp, *fp;
 922
 923         *device_path = NULL;
 924         *file_path = NULL;
 925         dp = efi_dp_dup(full_path);
 926         if (!dp)
 927                 return EFI_OUT_OF_RESOURCES;
 928         p = dp;
 929         while (!EFI_DP_TYPE(p, MEDIA_DEVICE, FILE_PATH)) {
 930                 p = efi_dp_next(p);
 931                 if (!p)
 932                         return EFI_OUT_OF_RESOURCES;
 933         }
 934         fp = efi_dp_dup(p);
 935         if (!fp)
 936                 return EFI_OUT_OF_RESOURCES;
 937         p->type = DEVICE_PATH_TYPE_END;
 938         p->sub_type = DEVICE_PATH_SUB_TYPE_END;
 939         p->length = sizeof(*p);
 940
 941         *device_path = dp;
 942         *file_path = fp;
 943         return EFI_SUCCESS;
 944 }
 945
 946 efi_status_t efi_dp_from_name(const char *dev, const char *devnr,
 947                               const char *path,
 948                               struct efi_device_path **device,
 949                               struct efi_device_path **file)
 950 {
 951         int is_net;
 952         struct blk_desc *desc = NULL;
 953         disk_partition_t fs_partition;
 954         int part = 0;
 955         char filename[32] = { 0 }; /* dp->str is u16[32] long */
 956         char *s;
 957
 958         if (path && !file)
 959                 return EFI_INVALID_PARAMETER;
 960
 961         is_net = !strcmp(dev, "Net");
 962         if (!is_net) {
 963                 part = blk_get_device_part_str(dev, devnr, &desc, &fs_partition,
 964                                                1);
 965                 if (part < 0)
 966                         return EFI_INVALID_PARAMETER;
 967
 968                 if (device)
 969                         *device = efi_dp_from_part(desc, part);
 970         } else {
 971 #ifdef CONFIG_NET
 972                 if (device)
 973                         *device = efi_dp_from_eth();
 974 #endif
 975         }
 976
 977         if (!path)
 978                 return EFI_SUCCESS;
 979
 980         if (!is_net) {
 981                 /* Add leading / to fs paths, because they're absolute */
 982                 snprintf(filename, sizeof(filename), "/%s", path);
 983         } else {
 984                 snprintf(filename, sizeof(filename), "%s", path);
 985         }
 986         /* DOS style file path: */
 987         s = filename;
 988         while ((s = strchr(s, '/')))
 989                 *s++ = '\\';
 990         *file = efi_dp_from_file(((!is_net && device) ? desc : NULL),
 991                                  part, filename);
 992
 993         return EFI_SUCCESS;
 994 }