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 #define U_BOOT_GUID \
  26         EFI_GUID(0xe61d73b9, 0xa384, 0x4acc, \
  27                  0xae, 0xab, 0x82, 0xe8, 0x28, 0xf3, 0x62, 0x8b)
  28
  29 /* template ROOT node: */
  30 static const struct efi_device_path_vendor ROOT = {
  31         .dp = {
  32                 .type     = DEVICE_PATH_TYPE_HARDWARE_DEVICE,
  33                 .sub_type = DEVICE_PATH_SUB_TYPE_VENDOR,
  34                 .length   = sizeof(ROOT),
  35         },
  36         .guid = U_BOOT_GUID,
  37 };
  38
  39 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
  40 /*
  41  * Determine if an MMC device is an SD card.
  42  *
  43  * @desc        block device descriptor
  44  * @return      true if the device is an SD card
  45  */
  46 static bool is_sd(struct blk_desc *desc)
  47 {
  48         struct mmc *mmc = find_mmc_device(desc->devnum);
  49
  50         if (!mmc)
  51                 return false;
  52
  53         return IS_SD(mmc) != 0U;
  54 }
  55 #endif
  56
  57 static void *dp_alloc(size_t sz)
  58 {
  59         void *buf;
  60
  61         if (efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, sz, &buf) !=
  62             EFI_SUCCESS) {
  63                 debug("EFI: ERROR: out of memory in %s\n", __func__);
  64                 return NULL;
  65         }
  66
  67         memset(buf, 0, sz);
  68         return buf;
  69 }
  70
  71 /*
  72  * Iterate to next block in device-path, terminating (returning NULL)
  73  * at /End* node.
  74  */
  75 struct efi_device_path *efi_dp_next(const struct efi_device_path *dp)
  76 {
  77         if (dp == NULL)
  78                 return NULL;
  79         if (dp->type == DEVICE_PATH_TYPE_END)
  80                 return NULL;
  81         dp = ((void *)dp) + dp->length;
  82         if (dp->type == DEVICE_PATH_TYPE_END)
  83                 return NULL;
  84         return (struct efi_device_path *)dp;
  85 }
  86
  87 /*
  88  * Compare two device-paths, stopping when the shorter of the two hits
  89  * an End* node.  This is useful to, for example, compare a device-path
  90  * representing a device with one representing a file on the device, or
  91  * a device with a parent device.
  92  */
  93 int efi_dp_match(const struct efi_device_path *a,
  94                  const struct efi_device_path *b)
  95 {
  96         while (1) {
  97                 int ret;
  98
  99                 ret = memcmp(&a->length, &b->length, sizeof(a->length));
 100                 if (ret)
 101                         return ret;
 102
 103                 ret = memcmp(a, b, a->length);
 104                 if (ret)
 105                         return ret;
 106
 107                 a = efi_dp_next(a);
 108                 b = efi_dp_next(b);
 109
 110                 if (!a || !b)
 111                         return 0;
 112         }
 113 }
 114
 115 /*
 116  * See UEFI spec (section 3.1.2, about short-form device-paths..
 117  * tl;dr: we can have a device-path that starts with a USB WWID
 118  * or USB Class node, and a few other cases which don't encode
 119  * the full device path with bus hierarchy:
 120  *
 121  *   - MESSAGING:USB_WWID
 122  *   - MESSAGING:USB_CLASS
 123  *   - MEDIA:FILE_PATH
 124  *   - MEDIA:HARD_DRIVE
 125  *   - MESSAGING:URI
 126  */
 127 static struct efi_device_path *shorten_path(struct efi_device_path *dp)
 128 {
 129         while (dp) {
 130                 /*
 131                  * TODO: Add MESSAGING:USB_WWID and MESSAGING:URI..
 132                  * in practice fallback.efi just uses MEDIA:HARD_DRIVE
 133                  * so not sure when we would see these other cases.
 134                  */
 135                 if (EFI_DP_TYPE(dp, MESSAGING_DEVICE, MSG_USB_CLASS) ||
 136                     EFI_DP_TYPE(dp, MEDIA_DEVICE, HARD_DRIVE_PATH) ||
 137                     EFI_DP_TYPE(dp, MEDIA_DEVICE, FILE_PATH))
 138                         return dp;
 139
 140                 dp = efi_dp_next(dp);
 141         }
 142
 143         return dp;
 144 }
 145
 146 static struct efi_object *find_obj(struct efi_device_path *dp, bool short_path,
 147                                    struct efi_device_path **rem)
 148 {
 149         struct efi_object *efiobj;
 150         efi_uintn_t dp_size = efi_dp_instance_size(dp);
 151
 152         list_for_each_entry(efiobj, &efi_obj_list, link) {
 153                 struct efi_handler *handler;
 154                 struct efi_device_path *obj_dp;
 155                 efi_status_t ret;
 156
 157                 ret = efi_search_protocol(efiobj->handle,
 158                                           &efi_guid_device_path, &handler);
 159                 if (ret != EFI_SUCCESS)
 160                         continue;
 161                 obj_dp = handler->protocol_interface;
 162
 163                 do {
 164                         if (efi_dp_match(dp, obj_dp) == 0) {
 165                                 if (rem) {
 166                                         /*
 167                                          * Allow partial matches, but inform
 168                                          * the caller.
 169                                          */
 170                                         *rem = ((void *)dp) +
 171                                                 efi_dp_instance_size(obj_dp);
 172                                         return efiobj;
 173                                 } else {
 174                                         /* Only return on exact matches */
 175                                         if (efi_dp_instance_size(obj_dp) ==
 176                                             dp_size)
 177                                                 return efiobj;
 178                                 }
 179                         }
 180
 181                         obj_dp = shorten_path(efi_dp_next(obj_dp));
 182                 } while (short_path && obj_dp);
 183         }
 184
 185         return NULL;
 186 }
 187
 188 /*
 189  * Find an efiobj from device-path, if 'rem' is not NULL, returns the
 190  * remaining part of the device path after the matched object.
 191  */
 192 struct efi_object *efi_dp_find_obj(struct efi_device_path *dp,
 193                                    struct efi_device_path **rem)
 194 {
 195         struct efi_object *efiobj;
 196
 197         /* Search for an exact match first */
 198         efiobj = find_obj(dp, false, NULL);
 199
 200         /* Then for a fuzzy match */
 201         if (!efiobj)
 202                 efiobj = find_obj(dp, false, rem);
 203
 204         /* And now for a fuzzy short match */
 205         if (!efiobj)
 206                 efiobj = find_obj(dp, true, rem);
 207
 208         return efiobj;
 209 }
 210
 211 /*
 212  * Determine the last device path node that is not the end node.
 213  *
 214  * @dp          device path
 215  * @return      last node before the end node if it exists
 216  *              otherwise NULL
 217  */
 218 const struct efi_device_path *efi_dp_last_node(const struct efi_device_path *dp)
 219 {
 220         struct efi_device_path *ret;
 221
 222         if (!dp || dp->type == DEVICE_PATH_TYPE_END)
 223                 return NULL;
 224         while (dp) {
 225                 ret = (struct efi_device_path *)dp;
 226                 dp = efi_dp_next(dp);
 227         }
 228         return ret;
 229 }
 230
 231 /* get size of the first device path instance excluding end node */
 232 efi_uintn_t efi_dp_instance_size(const struct efi_device_path *dp)
 233 {
 234         efi_uintn_t sz = 0;
 235
 236         if (!dp || dp->type == DEVICE_PATH_TYPE_END)
 237                 return 0;
 238         while (dp) {
 239                 sz += dp->length;
 240                 dp = efi_dp_next(dp);
 241         }
 242
 243         return sz;
 244 }
 245
 246 /* get size of multi-instance device path excluding end node */
 247 efi_uintn_t efi_dp_size(const struct efi_device_path *dp)
 248 {
 249         const struct efi_device_path *p = dp;
 250
 251         if (!p)
 252                 return 0;
 253         while (p->type != DEVICE_PATH_TYPE_END ||
 254                p->sub_type != DEVICE_PATH_SUB_TYPE_END)
 255                 p = (void *)p + p->length;
 256
 257         return (void *)p - (void *)dp;
 258 }
 259
 260 /* copy multi-instance device path */
 261 struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp)
 262 {
 263         struct efi_device_path *ndp;
 264         size_t sz = efi_dp_size(dp) + sizeof(END);
 265
 266         if (!dp)
 267                 return NULL;
 268
 269         ndp = dp_alloc(sz);
 270         if (!ndp)
 271                 return NULL;
 272         memcpy(ndp, dp, sz);
 273
 274         return ndp;
 275 }
 276
 277 struct efi_device_path *efi_dp_append(const struct efi_device_path *dp1,
 278                                       const struct efi_device_path *dp2)
 279 {
 280         struct efi_device_path *ret;
 281
 282         if (!dp1 && !dp2) {
 283                 /* return an end node */
 284                 ret = efi_dp_dup(&END);
 285         } else if (!dp1) {
 286                 ret = efi_dp_dup(dp2);
 287         } else if (!dp2) {
 288                 ret = efi_dp_dup(dp1);
 289         } else {
 290                 /* both dp1 and dp2 are non-null */
 291                 unsigned sz1 = efi_dp_size(dp1);
 292                 unsigned sz2 = efi_dp_size(dp2);
 293                 void *p = dp_alloc(sz1 + sz2 + sizeof(END));
 294                 if (!p)
 295                         return NULL;
 296                 memcpy(p, dp1, sz1);
 297                 /* the end node of the second device path has to be retained */
 298                 memcpy(p + sz1, dp2, sz2 + sizeof(END));
 299                 ret = p;
 300         }
 301
 302         return ret;
 303 }
 304
 305 struct efi_device_path *efi_dp_append_node(const struct efi_device_path *dp,
 306                                            const struct efi_device_path *node)
 307 {
 308         struct efi_device_path *ret;
 309
 310         if (!node && !dp) {
 311                 ret = efi_dp_dup(&END);
 312         } else if (!node) {
 313                 ret = efi_dp_dup(dp);
 314         } else if (!dp) {
 315                 size_t sz = node->length;
 316                 void *p = dp_alloc(sz + sizeof(END));
 317                 if (!p)
 318                         return NULL;
 319                 memcpy(p, node, sz);
 320                 memcpy(p + sz, &END, sizeof(END));
 321                 ret = p;
 322         } else {
 323                 /* both dp and node are non-null */
 324                 size_t sz = efi_dp_size(dp);
 325                 void *p = dp_alloc(sz + node->length + sizeof(END));
 326                 if (!p)
 327                         return NULL;
 328                 memcpy(p, dp, sz);
 329                 memcpy(p + sz, node, node->length);
 330                 memcpy(p + sz + node->length, &END, sizeof(END));
 331                 ret = p;
 332         }
 333
 334         return ret;
 335 }
 336
 337 struct efi_device_path *efi_dp_create_device_node(const u8 type,
 338                                                   const u8 sub_type,
 339                                                   const u16 length)
 340 {
 341         struct efi_device_path *ret;
 342
 343         ret = dp_alloc(length);
 344         if (!ret)
 345                 return ret;
 346         ret->type = type;
 347         ret->sub_type = sub_type;
 348         ret->length = length;
 349         return ret;
 350 }
 351
 352 struct efi_device_path *efi_dp_append_instance(
 353                 const struct efi_device_path *dp,
 354                 const struct efi_device_path *dpi)
 355 {
 356         size_t sz, szi;
 357         struct efi_device_path *p, *ret;
 358
 359         if (!dpi)
 360                 return NULL;
 361         if (!dp)
 362                 return efi_dp_dup(dpi);
 363         sz = efi_dp_size(dp);
 364         szi = efi_dp_instance_size(dpi);
 365         p = dp_alloc(sz + szi + 2 * sizeof(END));
 366         if (!p)
 367                 return NULL;
 368         ret = p;
 369         memcpy(p, dp, sz + sizeof(END));
 370         p = (void *)p + sz;
 371         p->sub_type = DEVICE_PATH_SUB_TYPE_INSTANCE_END;
 372         p = (void *)p + sizeof(END);
 373         memcpy(p, dpi, szi);
 374         p = (void *)p + szi;
 375         memcpy(p, &END, sizeof(END));
 376         return ret;
 377 }
 378
 379 struct efi_device_path *efi_dp_get_next_instance(struct efi_device_path **dp,
 380                                                  efi_uintn_t *size)
 381 {
 382         size_t sz;
 383         struct efi_device_path *p;
 384
 385         if (size)
 386                 *size = 0;
 387         if (!dp || !*dp)
 388                 return NULL;
 389         p = *dp;
 390         sz = efi_dp_instance_size(*dp);
 391         p = dp_alloc(sz + sizeof(END));
 392         if (!p)
 393                 return NULL;
 394         memcpy(p, *dp, sz + sizeof(END));
 395         *dp = (void *)*dp + sz;
 396         if ((*dp)->sub_type == DEVICE_PATH_SUB_TYPE_INSTANCE_END)
 397                 *dp = (void *)*dp + sizeof(END);
 398         else
 399                 *dp = NULL;
 400         if (size)
 401                 *size = sz + sizeof(END);
 402         return p;
 403 }
 404
 405 bool efi_dp_is_multi_instance(const struct efi_device_path *dp)
 406 {
 407         const struct efi_device_path *p = dp;
 408
 409         if (!p)
 410                 return false;
 411         while (p->type != DEVICE_PATH_TYPE_END)
 412                 p = (void *)p + p->length;
 413         return p->sub_type == DEVICE_PATH_SUB_TYPE_INSTANCE_END;
 414 }
 415
 416 #ifdef CONFIG_DM
 417 /* size of device-path not including END node for device and all parents
 418  * up to the root device.
 419  */
 420 static unsigned dp_size(struct udevice *dev)
 421 {
 422         if (!dev || !dev->driver)
 423                 return sizeof(ROOT);
 424
 425         switch (dev->driver->id) {
 426         case UCLASS_ROOT:
 427         case UCLASS_SIMPLE_BUS:
 428                 /* stop traversing parents at this point: */
 429                 return sizeof(ROOT);
 430         case UCLASS_ETH:
 431                 return dp_size(dev->parent) +
 432                         sizeof(struct efi_device_path_mac_addr);
 433 #ifdef CONFIG_BLK
 434         case UCLASS_BLK:
 435                 switch (dev->parent->uclass->uc_drv->id) {
 436 #ifdef CONFIG_IDE
 437                 case UCLASS_IDE:
 438                         return dp_size(dev->parent) +
 439                                 sizeof(struct efi_device_path_atapi);
 440 #endif
 441 #if defined(CONFIG_SCSI) && defined(CONFIG_DM_SCSI)
 442                 case UCLASS_SCSI:
 443                         return dp_size(dev->parent) +
 444                                 sizeof(struct efi_device_path_scsi);
 445 #endif
 446 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 447                 case UCLASS_MMC:
 448                         return dp_size(dev->parent) +
 449                                 sizeof(struct efi_device_path_sd_mmc_path);
 450 #endif
 451                 default:
 452                         return dp_size(dev->parent);
 453                 }
 454 #endif
 455 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 456         case UCLASS_MMC:
 457                 return dp_size(dev->parent) +
 458                         sizeof(struct efi_device_path_sd_mmc_path);
 459 #endif
 460         case UCLASS_MASS_STORAGE:
 461         case UCLASS_USB_HUB:
 462                 return dp_size(dev->parent) +
 463                         sizeof(struct efi_device_path_usb_class);
 464         default:
 465                 /* just skip over unknown classes: */
 466                 return dp_size(dev->parent);
 467         }
 468 }
 469
 470 /*
 471  * Recursively build a device path.
 472  *
 473  * @buf         pointer to the end of the device path
 474  * @dev         device
 475  * @return      pointer to the end of the device path
 476  */
 477 static void *dp_fill(void *buf, struct udevice *dev)
 478 {
 479         if (!dev || !dev->driver)
 480                 return buf;
 481
 482         switch (dev->driver->id) {
 483         case UCLASS_ROOT:
 484         case UCLASS_SIMPLE_BUS: {
 485                 /* stop traversing parents at this point: */
 486                 struct efi_device_path_vendor *vdp = buf;
 487                 *vdp = ROOT;
 488                 return &vdp[1];
 489         }
 490 #ifdef CONFIG_DM_ETH
 491         case UCLASS_ETH: {
 492                 struct efi_device_path_mac_addr *dp =
 493                         dp_fill(buf, dev->parent);
 494                 struct eth_pdata *pdata = dev->platdata;
 495
 496                 dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 497                 dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
 498                 dp->dp.length = sizeof(*dp);
 499                 memset(&dp->mac, 0, sizeof(dp->mac));
 500                 /* We only support IPv4 */
 501                 memcpy(&dp->mac, &pdata->enetaddr, ARP_HLEN);
 502                 /* Ethernet */
 503                 dp->if_type = 1;
 504                 return &dp[1];
 505         }
 506 #endif
 507 #ifdef CONFIG_BLK
 508         case UCLASS_BLK:
 509                 switch (dev->parent->uclass->uc_drv->id) {
 510 #ifdef CONFIG_IDE
 511                 case UCLASS_IDE: {
 512                         struct efi_device_path_atapi *dp =
 513                         dp_fill(buf, dev->parent);
 514                         struct blk_desc *desc = dev_get_uclass_platdata(dev);
 515
 516                         dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 517                         dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_ATAPI;
 518                         dp->dp.length = sizeof(*dp);
 519                         dp->logical_unit_number = desc->devnum;
 520                         dp->primary_secondary = IDE_BUS(desc->devnum);
 521                         dp->slave_master = desc->devnum %
 522                                 (CONFIG_SYS_IDE_MAXDEVICE /
 523                                  CONFIG_SYS_IDE_MAXBUS);
 524                         return &dp[1];
 525                         }
 526 #endif
 527 #if defined(CONFIG_SCSI) && defined(CONFIG_DM_SCSI)
 528                 case UCLASS_SCSI: {
 529                         struct efi_device_path_scsi *dp =
 530                                 dp_fill(buf, dev->parent);
 531                         struct blk_desc *desc = dev_get_uclass_platdata(dev);
 532
 533                         dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 534                         dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_SCSI;
 535                         dp->dp.length = sizeof(*dp);
 536                         dp->logical_unit_number = desc->lun;
 537                         dp->target_id = desc->target;
 538                         return &dp[1];
 539                         }
 540 #endif
 541 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 542                 case UCLASS_MMC: {
 543                         struct efi_device_path_sd_mmc_path *sddp =
 544                                 dp_fill(buf, dev->parent);
 545                         struct blk_desc *desc = dev_get_uclass_platdata(dev);
 546
 547                         sddp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 548                         sddp->dp.sub_type = is_sd(desc) ?
 549                                 DEVICE_PATH_SUB_TYPE_MSG_SD :
 550                                 DEVICE_PATH_SUB_TYPE_MSG_MMC;
 551                         sddp->dp.length   = sizeof(*sddp);
 552                         sddp->slot_number = dev->seq;
 553                         return &sddp[1];
 554                         }
 555 #endif
 556                 default:
 557                         debug("%s(%u) %s: unhandled parent class: %s (%u)\n",
 558                               __FILE__, __LINE__, __func__,
 559                               dev->name, dev->parent->uclass->uc_drv->id);
 560                         return dp_fill(buf, dev->parent);
 561                 }
 562 #endif
 563 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 564         case UCLASS_MMC: {
 565                 struct efi_device_path_sd_mmc_path *sddp =
 566                         dp_fill(buf, dev->parent);
 567                 struct mmc *mmc = mmc_get_mmc_dev(dev);
 568                 struct blk_desc *desc = mmc_get_blk_desc(mmc);
 569
 570                 sddp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 571                 sddp->dp.sub_type = is_sd(desc) ?
 572                         DEVICE_PATH_SUB_TYPE_MSG_SD :
 573                         DEVICE_PATH_SUB_TYPE_MSG_MMC;
 574                 sddp->dp.length   = sizeof(*sddp);
 575                 sddp->slot_number = dev->seq;
 576
 577                 return &sddp[1];
 578         }
 579 #endif
 580         case UCLASS_MASS_STORAGE:
 581         case UCLASS_USB_HUB: {
 582                 struct efi_device_path_usb_class *udp =
 583                         dp_fill(buf, dev->parent);
 584                 struct usb_device *udev = dev_get_parent_priv(dev);
 585                 struct usb_device_descriptor *desc = &udev->descriptor;
 586
 587                 udp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 588                 udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS;
 589                 udp->dp.length   = sizeof(*udp);
 590                 udp->vendor_id   = desc->idVendor;
 591                 udp->product_id  = desc->idProduct;
 592                 udp->device_class    = desc->bDeviceClass;
 593                 udp->device_subclass = desc->bDeviceSubClass;
 594                 udp->device_protocol = desc->bDeviceProtocol;
 595
 596                 return &udp[1];
 597         }
 598         default:
 599                 debug("%s(%u) %s: unhandled device class: %s (%u)\n",
 600                       __FILE__, __LINE__, __func__,
 601                       dev->name, dev->driver->id);
 602                 return dp_fill(buf, dev->parent);
 603         }
 604 }
 605
 606 /* Construct a device-path from a device: */
 607 struct efi_device_path *efi_dp_from_dev(struct udevice *dev)
 608 {
 609         void *buf, *start;
 610
 611         start = buf = dp_alloc(dp_size(dev) + sizeof(END));
 612         if (!buf)
 613                 return NULL;
 614         buf = dp_fill(buf, dev);
 615         *((struct efi_device_path *)buf) = END;
 616
 617         return start;
 618 }
 619 #endif
 620
 621 static unsigned dp_part_size(struct blk_desc *desc, int part)
 622 {
 623         unsigned dpsize;
 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                 dpsize = dp_size(dev);
 633         }
 634 #else
 635         dpsize = sizeof(ROOT) + sizeof(struct efi_device_path_usb);
 636 #endif
 637
 638         if (part == 0) /* the actual disk, not a partition */
 639                 return dpsize;
 640
 641         if (desc->part_type == PART_TYPE_ISO)
 642                 dpsize += sizeof(struct efi_device_path_cdrom_path);
 643         else
 644                 dpsize += sizeof(struct efi_device_path_hard_drive_path);
 645
 646         return dpsize;
 647 }
 648
 649 /*
 650  * Create a device node for a block device partition.
 651  *
 652  * @buf         buffer to which the device path is wirtten
 653  * @desc        block device descriptor
 654  * @part        partition number, 0 identifies a block device
 655  */
 656 static void *dp_part_node(void *buf, struct blk_desc *desc, int part)
 657 {
 658         disk_partition_t info;
 659
 660         part_get_info(desc, part, &info);
 661
 662         if (desc->part_type == PART_TYPE_ISO) {
 663                 struct efi_device_path_cdrom_path *cddp = buf;
 664
 665                 cddp->boot_entry = part;
 666                 cddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 667                 cddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_CDROM_PATH;
 668                 cddp->dp.length = sizeof(*cddp);
 669                 cddp->partition_start = info.start;
 670                 cddp->partition_end = info.size;
 671
 672                 buf = &cddp[1];
 673         } else {
 674                 struct efi_device_path_hard_drive_path *hddp = buf;
 675
 676                 hddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 677                 hddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH;
 678                 hddp->dp.length = sizeof(*hddp);
 679                 hddp->partition_number = part;
 680                 hddp->partition_start = info.start;
 681                 hddp->partition_end = info.size;
 682                 if (desc->part_type == PART_TYPE_EFI)
 683                         hddp->partmap_type = 2;
 684                 else
 685                         hddp->partmap_type = 1;
 686
 687                 switch (desc->sig_type) {
 688                 case SIG_TYPE_NONE:
 689                 default:
 690                         hddp->signature_type = 0;
 691                         memset(hddp->partition_signature, 0,
 692                                sizeof(hddp->partition_signature));
 693                         break;
 694                 case SIG_TYPE_MBR:
 695                         hddp->signature_type = 1;
 696                         memset(hddp->partition_signature, 0,
 697                                sizeof(hddp->partition_signature));
 698                         memcpy(hddp->partition_signature, &desc->mbr_sig,
 699                                sizeof(desc->mbr_sig));
 700                         break;
 701                 case SIG_TYPE_GUID:
 702                         hddp->signature_type = 2;
 703                         memcpy(hddp->partition_signature, &desc->guid_sig,
 704                                sizeof(hddp->partition_signature));
 705                         break;
 706                 }
 707
 708                 buf = &hddp[1];
 709         }
 710
 711         return buf;
 712 }
 713
 714 /*
 715  * Create a device path for a block device or one of its partitions.
 716  *
 717  * @buf         buffer to which the device path is wirtten
 718  * @desc        block device descriptor
 719  * @part        partition number, 0 identifies a block device
 720  */
 721 static void *dp_part_fill(void *buf, struct blk_desc *desc, int part)
 722 {
 723 #ifdef CONFIG_BLK
 724         {
 725                 struct udevice *dev;
 726                 int ret = blk_find_device(desc->if_type, desc->devnum, &dev);
 727
 728                 if (ret)
 729                         dev = desc->bdev->parent;
 730                 buf = dp_fill(buf, dev);
 731         }
 732 #else
 733         /*
 734          * We *could* make a more accurate path, by looking at if_type
 735          * and handling all the different cases like we do for non-
 736          * legacy (ie CONFIG_BLK=y) case.  But most important thing
 737          * is just to have a unique device-path for if_type+devnum.
 738          * So map things to a fictitious USB device.
 739          */
 740         struct efi_device_path_usb *udp;
 741
 742         memcpy(buf, &ROOT, sizeof(ROOT));
 743         buf += sizeof(ROOT);
 744
 745         udp = buf;
 746         udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 747         udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB;
 748         udp->dp.length = sizeof(*udp);
 749         udp->parent_port_number = desc->if_type;
 750         udp->usb_interface = desc->devnum;
 751         buf = &udp[1];
 752 #endif
 753
 754         if (part == 0) /* the actual disk, not a partition */
 755                 return buf;
 756
 757         return dp_part_node(buf, desc, part);
 758 }
 759
 760 /* Construct a device-path from a partition on a blk device: */
 761 struct efi_device_path *efi_dp_from_part(struct blk_desc *desc, int part)
 762 {
 763         void *buf, *start;
 764
 765         start = buf = dp_alloc(dp_part_size(desc, part) + sizeof(END));
 766         if (!buf)
 767                 return NULL;
 768
 769         buf = dp_part_fill(buf, desc, part);
 770
 771         *((struct efi_device_path *)buf) = END;
 772
 773         return start;
 774 }
 775
 776 /*
 777  * Create a device node for a block device partition.
 778  *
 779  * @buf         buffer to which the device path is wirtten
 780  * @desc        block device descriptor
 781  * @part        partition number, 0 identifies a block device
 782  */
 783 struct efi_device_path *efi_dp_part_node(struct blk_desc *desc, int part)
 784 {
 785         efi_uintn_t dpsize;
 786         void *buf;
 787
 788         if (desc->part_type == PART_TYPE_ISO)
 789                 dpsize = sizeof(struct efi_device_path_cdrom_path);
 790         else
 791                 dpsize = sizeof(struct efi_device_path_hard_drive_path);
 792         buf = dp_alloc(dpsize);
 793
 794         dp_part_node(buf, desc, part);
 795
 796         return buf;
 797 }
 798
 799 /* convert path to an UEFI style path (ie. DOS style backslashes and utf16) */
 800 static void path_to_uefi(u16 *uefi, const char *path)
 801 {
 802         while (*path) {
 803                 char c = *(path++);
 804                 if (c == '/')
 805                         c = '\\';
 806                 *(uefi++) = c;
 807         }
 808         *uefi = '\0';
 809 }
 810
 811 /*
 812  * If desc is NULL, this creates a path with only the file component,
 813  * otherwise it creates a full path with both device and file components
 814  */
 815 struct efi_device_path *efi_dp_from_file(struct blk_desc *desc, int part,
 816                 const char *path)
 817 {
 818         struct efi_device_path_file_path *fp;
 819         void *buf, *start;
 820         unsigned dpsize = 0, fpsize;
 821
 822         if (desc)
 823                 dpsize = dp_part_size(desc, part);
 824
 825         fpsize = sizeof(struct efi_device_path) + 2 * (strlen(path) + 1);
 826         dpsize += fpsize;
 827
 828         start = buf = dp_alloc(dpsize + sizeof(END));
 829         if (!buf)
 830                 return NULL;
 831
 832         if (desc)
 833                 buf = dp_part_fill(buf, desc, part);
 834
 835         /* add file-path: */
 836         fp = buf;
 837         fp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 838         fp->dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
 839         fp->dp.length = fpsize;
 840         path_to_uefi(fp->str, path);
 841         buf += fpsize;
 842
 843         *((struct efi_device_path *)buf) = END;
 844
 845         return start;
 846 }
 847
 848 #ifdef CONFIG_NET
 849 struct efi_device_path *efi_dp_from_eth(void)
 850 {
 851 #ifndef CONFIG_DM_ETH
 852         struct efi_device_path_mac_addr *ndp;
 853 #endif
 854         void *buf, *start;
 855         unsigned dpsize = 0;
 856
 857         assert(eth_get_dev());
 858
 859 #ifdef CONFIG_DM_ETH
 860         dpsize += dp_size(eth_get_dev());
 861 #else
 862         dpsize += sizeof(ROOT);
 863         dpsize += sizeof(*ndp);
 864 #endif
 865
 866         start = buf = dp_alloc(dpsize + sizeof(END));
 867         if (!buf)
 868                 return NULL;
 869
 870 #ifdef CONFIG_DM_ETH
 871         buf = dp_fill(buf, eth_get_dev());
 872 #else
 873         memcpy(buf, &ROOT, sizeof(ROOT));
 874         buf += sizeof(ROOT);
 875
 876         ndp = buf;
 877         ndp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 878         ndp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
 879         ndp->dp.length = sizeof(*ndp);
 880         ndp->if_type = 1; /* Ethernet */
 881         memcpy(ndp->mac.addr, eth_get_ethaddr(), ARP_HLEN);
 882         buf = &ndp[1];
 883 #endif
 884
 885         *((struct efi_device_path *)buf) = END;
 886
 887         return start;
 888 }
 889 #endif
 890
 891 /* Construct a device-path for memory-mapped image */
 892 struct efi_device_path *efi_dp_from_mem(uint32_t memory_type,
 893                                         uint64_t start_address,
 894                                         uint64_t end_address)
 895 {
 896         struct efi_device_path_memory *mdp;
 897         void *buf, *start;
 898
 899         start = buf = dp_alloc(sizeof(*mdp) + sizeof(END));
 900         if (!buf)
 901                 return NULL;
 902
 903         mdp = buf;
 904         mdp->dp.type = DEVICE_PATH_TYPE_HARDWARE_DEVICE;
 905         mdp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MEMORY;
 906         mdp->dp.length = sizeof(*mdp);
 907         mdp->memory_type = memory_type;
 908         mdp->start_address = start_address;
 909         mdp->end_address = end_address;
 910         buf = &mdp[1];
 911
 912         *((struct efi_device_path *)buf) = END;
 913
 914         return start;
 915 }
 916
 917 /*
 918  * Helper to split a full device path (containing both device and file
 919  * parts) into it's constituent parts.
 920  */
 921 efi_status_t efi_dp_split_file_path(struct efi_device_path *full_path,
 922                                     struct efi_device_path **device_path,
 923                                     struct efi_device_path **file_path)
 924 {
 925         struct efi_device_path *p, *dp, *fp;
 926
 927         *device_path = NULL;
 928         *file_path = NULL;
 929         dp = efi_dp_dup(full_path);
 930         if (!dp)
 931                 return EFI_OUT_OF_RESOURCES;
 932         p = dp;
 933         while (!EFI_DP_TYPE(p, MEDIA_DEVICE, FILE_PATH)) {
 934                 p = efi_dp_next(p);
 935                 if (!p)
 936                         return EFI_OUT_OF_RESOURCES;
 937         }
 938         fp = efi_dp_dup(p);
 939         if (!fp)
 940                 return EFI_OUT_OF_RESOURCES;
 941         p->type = DEVICE_PATH_TYPE_END;
 942         p->sub_type = DEVICE_PATH_SUB_TYPE_END;
 943         p->length = sizeof(*p);
 944
 945         *device_path = dp;
 946         *file_path = fp;
 947         return EFI_SUCCESS;
 948 }