lib/efi_loader/efi_device_path.c

   1 /*
   2  * EFI device path from u-boot device-model mapping
   3  *
   4  * (C) Copyright 2017 Rob Clark
   5  *
   6  * SPDX-License-Identifier:     GPL-2.0+
   7  */
   8
   9 #define LOG_CATEGORY LOGL_ERR
  10
  11 #include <common.h>
  12 #include <blk.h>
  13 #include <dm.h>
  14 #include <usb.h>
  15 #include <mmc.h>
  16 #include <efi_loader.h>
  17 #include <inttypes.h>
  18 #include <part.h>
  19
  20 /* template END node: */
  21 static const struct efi_device_path END = {
  22         .type     = DEVICE_PATH_TYPE_END,
  23         .sub_type = DEVICE_PATH_SUB_TYPE_END,
  24         .length   = sizeof(END),
  25 };
  26
  27 #define U_BOOT_GUID \
  28         EFI_GUID(0xe61d73b9, 0xa384, 0x4acc, \
  29                  0xae, 0xab, 0x82, 0xe8, 0x28, 0xf3, 0x62, 0x8b)
  30
  31 /* template ROOT node: */
  32 static const struct efi_device_path_vendor ROOT = {
  33         .dp = {
  34                 .type     = DEVICE_PATH_TYPE_HARDWARE_DEVICE,
  35                 .sub_type = DEVICE_PATH_SUB_TYPE_VENDOR,
  36                 .length   = sizeof(ROOT),
  37         },
  38         .guid = U_BOOT_GUID,
  39 };
  40
  41 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
  42 /*
  43  * Determine if an MMC device is an SD card.
  44  *
  45  * @desc        block device descriptor
  46  * @return      true if the device is an SD card
  47  */
  48 static bool is_sd(struct blk_desc *desc)
  49 {
  50         struct mmc *mmc = find_mmc_device(desc->devnum);
  51
  52         if (!mmc)
  53                 return false;
  54
  55         return IS_SD(mmc) != 0U;
  56 }
  57 #endif
  58
  59 static void *dp_alloc(size_t sz)
  60 {
  61         void *buf;
  62
  63         if (efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, sz, &buf) !=
  64             EFI_SUCCESS) {
  65                 debug("EFI: ERROR: out of memory in %s\n", __func__);
  66                 return NULL;
  67         }
  68
  69         memset(buf, 0, sz);
  70         return buf;
  71 }
  72
  73 /*
  74  * Iterate to next block in device-path, terminating (returning NULL)
  75  * at /End* node.
  76  */
  77 struct efi_device_path *efi_dp_next(const struct efi_device_path *dp)
  78 {
  79         if (dp == NULL)
  80                 return NULL;
  81         if (dp->type == DEVICE_PATH_TYPE_END)
  82                 return NULL;
  83         dp = ((void *)dp) + dp->length;
  84         if (dp->type == DEVICE_PATH_TYPE_END)
  85                 return NULL;
  86         return (struct efi_device_path *)dp;
  87 }
  88
  89 /*
  90  * Compare two device-paths, stopping when the shorter of the two hits
  91  * an End* node.  This is useful to, for example, compare a device-path
  92  * representing a device with one representing a file on the device, or
  93  * a device with a parent device.
  94  */
  95 int efi_dp_match(const struct efi_device_path *a,
  96                  const struct efi_device_path *b)
  97 {
  98         while (1) {
  99                 int ret;
 100
 101                 ret = memcmp(&a->length, &b->length, sizeof(a->length));
 102                 if (ret)
 103                         return ret;
 104
 105                 ret = memcmp(a, b, a->length);
 106                 if (ret)
 107                         return ret;
 108
 109                 a = efi_dp_next(a);
 110                 b = efi_dp_next(b);
 111
 112                 if (!a || !b)
 113                         return 0;
 114         }
 115 }
 116
 117 /*
 118  * See UEFI spec (section 3.1.2, about short-form device-paths..
 119  * tl;dr: we can have a device-path that starts with a USB WWID
 120  * or USB Class node, and a few other cases which don't encode
 121  * the full device path with bus hierarchy:
 122  *
 123  *   - MESSAGING:USB_WWID
 124  *   - MESSAGING:USB_CLASS
 125  *   - MEDIA:FILE_PATH
 126  *   - MEDIA:HARD_DRIVE
 127  *   - MESSAGING:URI
 128  */
 129 static struct efi_device_path *shorten_path(struct efi_device_path *dp)
 130 {
 131         while (dp) {
 132                 /*
 133                  * TODO: Add MESSAGING:USB_WWID and MESSAGING:URI..
 134                  * in practice fallback.efi just uses MEDIA:HARD_DRIVE
 135                  * so not sure when we would see these other cases.
 136                  */
 137                 if (EFI_DP_TYPE(dp, MESSAGING_DEVICE, MSG_USB_CLASS) ||
 138                     EFI_DP_TYPE(dp, MEDIA_DEVICE, HARD_DRIVE_PATH) ||
 139                     EFI_DP_TYPE(dp, MEDIA_DEVICE, FILE_PATH))
 140                         return dp;
 141
 142                 dp = efi_dp_next(dp);
 143         }
 144
 145         return dp;
 146 }
 147
 148 static struct efi_object *find_obj(struct efi_device_path *dp, bool short_path,
 149                                    struct efi_device_path **rem)
 150 {
 151         struct efi_object *efiobj;
 152         efi_uintn_t dp_size = efi_dp_instance_size(dp);
 153
 154         list_for_each_entry(efiobj, &efi_obj_list, link) {
 155                 struct efi_handler *handler;
 156                 struct efi_device_path *obj_dp;
 157                 efi_status_t ret;
 158
 159                 ret = efi_search_protocol(efiobj->handle,
 160                                           &efi_guid_device_path, &handler);
 161                 if (ret != EFI_SUCCESS)
 162                         continue;
 163                 obj_dp = handler->protocol_interface;
 164
 165                 do {
 166                         if (efi_dp_match(dp, obj_dp) == 0) {
 167                                 if (rem) {
 168                                         /*
 169                                          * Allow partial matches, but inform
 170                                          * the caller.
 171                                          */
 172                                         *rem = ((void *)dp) +
 173                                                 efi_dp_instance_size(obj_dp);
 174                                         return efiobj;
 175                                 } else {
 176                                         /* Only return on exact matches */
 177                                         if (efi_dp_instance_size(obj_dp) ==
 178                                             dp_size)
 179                                                 return efiobj;
 180                                 }
 181                         }
 182
 183                         obj_dp = shorten_path(efi_dp_next(obj_dp));
 184                 } while (short_path && obj_dp);
 185         }
 186
 187         return NULL;
 188 }
 189
 190 /*
 191  * Find an efiobj from device-path, if 'rem' is not NULL, returns the
 192  * remaining part of the device path after the matched object.
 193  */
 194 struct efi_object *efi_dp_find_obj(struct efi_device_path *dp,
 195                                    struct efi_device_path **rem)
 196 {
 197         struct efi_object *efiobj;
 198
 199         /* Search for an exact match first */
 200         efiobj = find_obj(dp, false, NULL);
 201
 202         /* Then for a fuzzy match */
 203         if (!efiobj)
 204                 efiobj = find_obj(dp, false, rem);
 205
 206         /* And now for a fuzzy short match */
 207         if (!efiobj)
 208                 efiobj = find_obj(dp, true, rem);
 209
 210         return efiobj;
 211 }
 212
 213 /*
 214  * Determine the last device path node that is not the end node.
 215  *
 216  * @dp          device path
 217  * @return      last node before the end node if it exists
 218  *              otherwise NULL
 219  */
 220 const struct efi_device_path *efi_dp_last_node(const struct efi_device_path *dp)
 221 {
 222         struct efi_device_path *ret;
 223
 224         if (!dp || dp->type == DEVICE_PATH_TYPE_END)
 225                 return NULL;
 226         while (dp) {
 227                 ret = (struct efi_device_path *)dp;
 228                 dp = efi_dp_next(dp);
 229         }
 230         return ret;
 231 }
 232
 233 /* get size of the first device path instance excluding end node */
 234 efi_uintn_t efi_dp_instance_size(const struct efi_device_path *dp)
 235 {
 236         efi_uintn_t sz = 0;
 237
 238         if (!dp || dp->type == DEVICE_PATH_TYPE_END)
 239                 return 0;
 240         while (dp) {
 241                 sz += dp->length;
 242                 dp = efi_dp_next(dp);
 243         }
 244
 245         return sz;
 246 }
 247
 248 /* get size of multi-instance device path excluding end node */
 249 efi_uintn_t efi_dp_size(const struct efi_device_path *dp)
 250 {
 251         const struct efi_device_path *p = dp;
 252
 253         if (!p)
 254                 return 0;
 255         while (p->type != DEVICE_PATH_TYPE_END ||
 256                p->sub_type != DEVICE_PATH_SUB_TYPE_END)
 257                 p = (void *)p + p->length;
 258
 259         return (void *)p - (void *)dp;
 260 }
 261
 262 /* copy multi-instance device path */
 263 struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp)
 264 {
 265         struct efi_device_path *ndp;
 266         size_t sz = efi_dp_size(dp) + sizeof(END);
 267
 268         if (!dp)
 269                 return NULL;
 270
 271         ndp = dp_alloc(sz);
 272         if (!ndp)
 273                 return NULL;
 274         memcpy(ndp, dp, sz);
 275
 276         return ndp;
 277 }
 278
 279 struct efi_device_path *efi_dp_append(const struct efi_device_path *dp1,
 280                                       const struct efi_device_path *dp2)
 281 {
 282         struct efi_device_path *ret;
 283
 284         if (!dp1 && !dp2) {
 285                 /* return an end node */
 286                 ret = efi_dp_dup(&END);
 287         } else if (!dp1) {
 288                 ret = efi_dp_dup(dp2);
 289         } else if (!dp2) {
 290                 ret = efi_dp_dup(dp1);
 291         } else {
 292                 /* both dp1 and dp2 are non-null */
 293                 unsigned sz1 = efi_dp_size(dp1);
 294                 unsigned sz2 = efi_dp_size(dp2);
 295                 void *p = dp_alloc(sz1 + sz2 + sizeof(END));
 296                 if (!p)
 297                         return NULL;
 298                 memcpy(p, dp1, sz1);
 299                 /* the end node of the second device path has to be retained */
 300                 memcpy(p + sz1, dp2, sz2 + sizeof(END));
 301                 ret = p;
 302         }
 303
 304         return ret;
 305 }
 306
 307 struct efi_device_path *efi_dp_append_node(const struct efi_device_path *dp,
 308                                            const struct efi_device_path *node)
 309 {
 310         struct efi_device_path *ret;
 311
 312         if (!node && !dp) {
 313                 ret = efi_dp_dup(&END);
 314         } else if (!node) {
 315                 ret = efi_dp_dup(dp);
 316         } else if (!dp) {
 317                 size_t sz = node->length;
 318                 void *p = dp_alloc(sz + sizeof(END));
 319                 if (!p)
 320                         return NULL;
 321                 memcpy(p, node, sz);
 322                 memcpy(p + sz, &END, sizeof(END));
 323                 ret = p;
 324         } else {
 325                 /* both dp and node are non-null */
 326                 size_t sz = efi_dp_size(dp);
 327                 void *p = dp_alloc(sz + node->length + sizeof(END));
 328                 if (!p)
 329                         return NULL;
 330                 memcpy(p, dp, sz);
 331                 memcpy(p + sz, node, node->length);
 332                 memcpy(p + sz + node->length, &END, sizeof(END));
 333                 ret = p;
 334         }
 335
 336         return ret;
 337 }
 338
 339 struct efi_device_path *efi_dp_create_device_node(const u8 type,
 340                                                   const u8 sub_type,
 341                                                   const u16 length)
 342 {
 343         struct efi_device_path *ret;
 344
 345         ret = dp_alloc(length);
 346         if (!ret)
 347                 return ret;
 348         ret->type = type;
 349         ret->sub_type = sub_type;
 350         ret->length = length;
 351         return ret;
 352 }
 353
 354 struct efi_device_path *efi_dp_append_instance(
 355                 const struct efi_device_path *dp,
 356                 const struct efi_device_path *dpi)
 357 {
 358         size_t sz, szi;
 359         struct efi_device_path *p, *ret;
 360
 361         if (!dpi)
 362                 return NULL;
 363         if (!dp)
 364                 return efi_dp_dup(dpi);
 365         sz = efi_dp_size(dp);
 366         szi = efi_dp_instance_size(dpi);
 367         p = dp_alloc(sz + szi + 2 * sizeof(END));
 368         if (!p)
 369                 return NULL;
 370         ret = p;
 371         memcpy(p, dp, sz + sizeof(END));
 372         p = (void *)p + sz;
 373         p->sub_type = DEVICE_PATH_SUB_TYPE_INSTANCE_END;
 374         p = (void *)p + sizeof(END);
 375         memcpy(p, dpi, szi);
 376         p = (void *)p + szi;
 377         memcpy(p, &END, sizeof(END));
 378         return ret;
 379 }
 380
 381 struct efi_device_path *efi_dp_get_next_instance(struct efi_device_path **dp,
 382                                                  efi_uintn_t *size)
 383 {
 384         size_t sz;
 385         struct efi_device_path *p;
 386
 387         if (size)
 388                 *size = 0;
 389         if (!dp || !*dp)
 390                 return NULL;
 391         p = *dp;
 392         sz = efi_dp_instance_size(*dp);
 393         p = dp_alloc(sz + sizeof(END));
 394         if (!p)
 395                 return NULL;
 396         memcpy(p, *dp, sz + sizeof(END));
 397         *dp = (void *)*dp + sz;
 398         if ((*dp)->sub_type == DEVICE_PATH_SUB_TYPE_INSTANCE_END)
 399                 *dp = (void *)*dp + sizeof(END);
 400         else
 401                 *dp = NULL;
 402         if (size)
 403                 *size = sz + sizeof(END);
 404         return p;
 405 }
 406
 407 bool efi_dp_is_multi_instance(const struct efi_device_path *dp)
 408 {
 409         const struct efi_device_path *p = dp;
 410
 411         if (!p)
 412                 return false;
 413         while (p->type != DEVICE_PATH_TYPE_END)
 414                 p = (void *)p + p->length;
 415         return p->sub_type == DEVICE_PATH_SUB_TYPE_INSTANCE_END;
 416 }
 417
 418 #ifdef CONFIG_DM
 419 /* size of device-path not including END node for device and all parents
 420  * up to the root device.
 421  */
 422 static unsigned dp_size(struct udevice *dev)
 423 {
 424         if (!dev || !dev->driver)
 425                 return sizeof(ROOT);
 426
 427         switch (dev->driver->id) {
 428         case UCLASS_ROOT:
 429         case UCLASS_SIMPLE_BUS:
 430                 /* stop traversing parents at this point: */
 431                 return sizeof(ROOT);
 432         case UCLASS_ETH:
 433                 return dp_size(dev->parent) +
 434                         sizeof(struct efi_device_path_mac_addr);
 435 #ifdef CONFIG_BLK
 436         case UCLASS_BLK:
 437                 switch (dev->parent->uclass->uc_drv->id) {
 438 #ifdef CONFIG_IDE
 439                 case UCLASS_IDE:
 440                         return dp_size(dev->parent) +
 441                                 sizeof(struct efi_device_path_atapi);
 442 #endif
 443 #if defined(CONFIG_SCSI) && defined(CONFIG_DM_SCSI)
 444                 case UCLASS_SCSI:
 445                         return dp_size(dev->parent) +
 446                                 sizeof(struct efi_device_path_scsi);
 447 #endif
 448 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 449                 case UCLASS_MMC:
 450                         return dp_size(dev->parent) +
 451                                 sizeof(struct efi_device_path_sd_mmc_path);
 452 #endif
 453                 default:
 454                         return dp_size(dev->parent);
 455                 }
 456 #endif
 457 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 458         case UCLASS_MMC:
 459                 return dp_size(dev->parent) +
 460                         sizeof(struct efi_device_path_sd_mmc_path);
 461 #endif
 462         case UCLASS_MASS_STORAGE:
 463         case UCLASS_USB_HUB:
 464                 return dp_size(dev->parent) +
 465                         sizeof(struct efi_device_path_usb_class);
 466         default:
 467                 /* just skip over unknown classes: */
 468                 return dp_size(dev->parent);
 469         }
 470 }
 471
 472 /*
 473  * Recursively build a device path.
 474  *
 475  * @buf         pointer to the end of the device path
 476  * @dev         device
 477  * @return      pointer to the end of the device path
 478  */
 479 static void *dp_fill(void *buf, struct udevice *dev)
 480 {
 481         if (!dev || !dev->driver)
 482                 return buf;
 483
 484         switch (dev->driver->id) {
 485         case UCLASS_ROOT:
 486         case UCLASS_SIMPLE_BUS: {
 487                 /* stop traversing parents at this point: */
 488                 struct efi_device_path_vendor *vdp = buf;
 489                 *vdp = ROOT;
 490                 return &vdp[1];
 491         }
 492 #ifdef CONFIG_DM_ETH
 493         case UCLASS_ETH: {
 494                 struct efi_device_path_mac_addr *dp =
 495                         dp_fill(buf, dev->parent);
 496                 struct eth_pdata *pdata = dev->platdata;
 497
 498                 dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 499                 dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
 500                 dp->dp.length = sizeof(*dp);
 501                 memset(&dp->mac, 0, sizeof(dp->mac));
 502                 /* We only support IPv4 */
 503                 memcpy(&dp->mac, &pdata->enetaddr, ARP_HLEN);
 504                 /* Ethernet */
 505                 dp->if_type = 1;
 506                 return &dp[1];
 507         }
 508 #endif
 509 #ifdef CONFIG_BLK
 510         case UCLASS_BLK:
 511                 switch (dev->parent->uclass->uc_drv->id) {
 512 #ifdef CONFIG_IDE
 513                 case UCLASS_IDE: {
 514                         struct efi_device_path_atapi *dp =
 515                         dp_fill(buf, dev->parent);
 516                         struct blk_desc *desc = dev_get_uclass_platdata(dev);
 517
 518                         dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 519                         dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_ATAPI;
 520                         dp->dp.length = sizeof(*dp);
 521                         dp->logical_unit_number = desc->devnum;
 522                         dp->primary_secondary = IDE_BUS(desc->devnum);
 523                         dp->slave_master = desc->devnum %
 524                                 (CONFIG_SYS_IDE_MAXDEVICE /
 525                                  CONFIG_SYS_IDE_MAXBUS);
 526                         return &dp[1];
 527                         }
 528 #endif
 529 #if defined(CONFIG_SCSI) && defined(CONFIG_DM_SCSI)
 530                 case UCLASS_SCSI: {
 531                         struct efi_device_path_scsi *dp =
 532                                 dp_fill(buf, dev->parent);
 533                         struct blk_desc *desc = dev_get_uclass_platdata(dev);
 534
 535                         dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 536                         dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_SCSI;
 537                         dp->dp.length = sizeof(*dp);
 538                         dp->logical_unit_number = desc->lun;
 539                         dp->target_id = desc->target;
 540                         return &dp[1];
 541                         }
 542 #endif
 543 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 544                 case UCLASS_MMC: {
 545                         struct efi_device_path_sd_mmc_path *sddp =
 546                                 dp_fill(buf, dev->parent);
 547                         struct blk_desc *desc = dev_get_uclass_platdata(dev);
 548
 549                         sddp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 550                         sddp->dp.sub_type = is_sd(desc) ?
 551                                 DEVICE_PATH_SUB_TYPE_MSG_SD :
 552                                 DEVICE_PATH_SUB_TYPE_MSG_MMC;
 553                         sddp->dp.length   = sizeof(*sddp);
 554                         sddp->slot_number = dev->seq;
 555                         return &sddp[1];
 556                         }
 557 #endif
 558                 default:
 559                         debug("%s(%u) %s: unhandled parent class: %s (%u)\n",
 560                               __FILE__, __LINE__, __func__,
 561                               dev->name, dev->parent->uclass->uc_drv->id);
 562                         return dp_fill(buf, dev->parent);
 563                 }
 564 #endif
 565 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 566         case UCLASS_MMC: {
 567                 struct efi_device_path_sd_mmc_path *sddp =
 568                         dp_fill(buf, dev->parent);
 569                 struct mmc *mmc = mmc_get_mmc_dev(dev);
 570                 struct blk_desc *desc = mmc_get_blk_desc(mmc);
 571
 572                 sddp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 573                 sddp->dp.sub_type = is_sd(desc) ?
 574                         DEVICE_PATH_SUB_TYPE_MSG_SD :
 575                         DEVICE_PATH_SUB_TYPE_MSG_MMC;
 576                 sddp->dp.length   = sizeof(*sddp);
 577                 sddp->slot_number = dev->seq;
 578
 579                 return &sddp[1];
 580         }
 581 #endif
 582         case UCLASS_MASS_STORAGE:
 583         case UCLASS_USB_HUB: {
 584                 struct efi_device_path_usb_class *udp =
 585                         dp_fill(buf, dev->parent);
 586                 struct usb_device *udev = dev_get_parent_priv(dev);
 587                 struct usb_device_descriptor *desc = &udev->descriptor;
 588
 589                 udp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 590                 udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS;
 591                 udp->dp.length   = sizeof(*udp);
 592                 udp->vendor_id   = desc->idVendor;
 593                 udp->product_id  = desc->idProduct;
 594                 udp->device_class    = desc->bDeviceClass;
 595                 udp->device_subclass = desc->bDeviceSubClass;
 596                 udp->device_protocol = desc->bDeviceProtocol;
 597
 598                 return &udp[1];
 599         }
 600         default:
 601                 debug("%s(%u) %s: unhandled device class: %s (%u)\n",
 602                       __FILE__, __LINE__, __func__,
 603                       dev->name, dev->driver->id);
 604                 return dp_fill(buf, dev->parent);
 605         }
 606 }
 607
 608 /* Construct a device-path from a device: */
 609 struct efi_device_path *efi_dp_from_dev(struct udevice *dev)
 610 {
 611         void *buf, *start;
 612
 613         start = buf = dp_alloc(dp_size(dev) + sizeof(END));
 614         if (!buf)
 615                 return NULL;
 616         buf = dp_fill(buf, dev);
 617         *((struct efi_device_path *)buf) = END;
 618
 619         return start;
 620 }
 621 #endif
 622
 623 static unsigned dp_part_size(struct blk_desc *desc, int part)
 624 {
 625         unsigned dpsize;
 626
 627 #ifdef CONFIG_BLK
 628         {
 629                 struct udevice *dev;
 630                 int ret = blk_find_device(desc->if_type, desc->devnum, &dev);
 631
 632                 if (ret)
 633                         dev = desc->bdev->parent;
 634                 dpsize = dp_size(dev);
 635         }
 636 #else
 637         dpsize = sizeof(ROOT) + sizeof(struct efi_device_path_usb);
 638 #endif
 639
 640         if (part == 0) /* the actual disk, not a partition */
 641                 return dpsize;
 642
 643         if (desc->part_type == PART_TYPE_ISO)
 644                 dpsize += sizeof(struct efi_device_path_cdrom_path);
 645         else
 646                 dpsize += sizeof(struct efi_device_path_hard_drive_path);
 647
 648         return dpsize;
 649 }
 650
 651 /*
 652  * Create a device node for a block device partition.
 653  *
 654  * @buf         buffer to which the device path is wirtten
 655  * @desc        block device descriptor
 656  * @part        partition number, 0 identifies a block device
 657  */
 658 static void *dp_part_node(void *buf, struct blk_desc *desc, int part)
 659 {
 660         disk_partition_t info;
 661
 662         part_get_info(desc, part, &info);
 663
 664         if (desc->part_type == PART_TYPE_ISO) {
 665                 struct efi_device_path_cdrom_path *cddp = buf;
 666
 667                 cddp->boot_entry = part;
 668                 cddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 669                 cddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_CDROM_PATH;
 670                 cddp->dp.length = sizeof(*cddp);
 671                 cddp->partition_start = info.start;
 672                 cddp->partition_end = info.size;
 673
 674                 buf = &cddp[1];
 675         } else {
 676                 struct efi_device_path_hard_drive_path *hddp = buf;
 677
 678                 hddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 679                 hddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH;
 680                 hddp->dp.length = sizeof(*hddp);
 681                 hddp->partition_number = part;
 682                 hddp->partition_start = info.start;
 683                 hddp->partition_end = info.size;
 684                 if (desc->part_type == PART_TYPE_EFI)
 685                         hddp->partmap_type = 2;
 686                 else
 687                         hddp->partmap_type = 1;
 688
 689                 switch (desc->sig_type) {
 690                 case SIG_TYPE_NONE:
 691                 default:
 692                         hddp->signature_type = 0;
 693                         memset(hddp->partition_signature, 0,
 694                                sizeof(hddp->partition_signature));
 695                         break;
 696                 case SIG_TYPE_MBR:
 697                         hddp->signature_type = 1;
 698                         memset(hddp->partition_signature, 0,
 699                                sizeof(hddp->partition_signature));
 700                         memcpy(hddp->partition_signature, &desc->mbr_sig,
 701                                sizeof(desc->mbr_sig));
 702                         break;
 703                 case SIG_TYPE_GUID:
 704                         hddp->signature_type = 2;
 705                         memcpy(hddp->partition_signature, &desc->guid_sig,
 706                                sizeof(hddp->partition_signature));
 707                         break;
 708                 }
 709
 710                 buf = &hddp[1];
 711         }
 712
 713         return buf;
 714 }
 715
 716 /*
 717  * Create a device path for a block device or one of its partitions.
 718  *
 719  * @buf         buffer to which the device path is wirtten
 720  * @desc        block device descriptor
 721  * @part        partition number, 0 identifies a block device
 722  */
 723 static void *dp_part_fill(void *buf, struct blk_desc *desc, int part)
 724 {
 725 #ifdef CONFIG_BLK
 726         {
 727                 struct udevice *dev;
 728                 int ret = blk_find_device(desc->if_type, desc->devnum, &dev);
 729
 730                 if (ret)
 731                         dev = desc->bdev->parent;
 732                 buf = dp_fill(buf, dev);
 733         }
 734 #else
 735         /*
 736          * We *could* make a more accurate path, by looking at if_type
 737          * and handling all the different cases like we do for non-
 738          * legacy (ie CONFIG_BLK=y) case.  But most important thing
 739          * is just to have a unique device-path for if_type+devnum.
 740          * So map things to a fictitious USB device.
 741          */
 742         struct efi_device_path_usb *udp;
 743
 744         memcpy(buf, &ROOT, sizeof(ROOT));
 745         buf += sizeof(ROOT);
 746
 747         udp = buf;
 748         udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 749         udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB;
 750         udp->dp.length = sizeof(*udp);
 751         udp->parent_port_number = desc->if_type;
 752         udp->usb_interface = desc->devnum;
 753         buf = &udp[1];
 754 #endif
 755
 756         if (part == 0) /* the actual disk, not a partition */
 757                 return buf;
 758
 759         return dp_part_node(buf, desc, part);
 760 }
 761
 762 /* Construct a device-path from a partition on a blk device: */
 763 struct efi_device_path *efi_dp_from_part(struct blk_desc *desc, int part)
 764 {
 765         void *buf, *start;
 766
 767         start = buf = dp_alloc(dp_part_size(desc, part) + sizeof(END));
 768         if (!buf)
 769                 return NULL;
 770
 771         buf = dp_part_fill(buf, desc, part);
 772
 773         *((struct efi_device_path *)buf) = END;
 774
 775         return start;
 776 }
 777
 778 /*
 779  * Create a device node for a block device partition.
 780  *
 781  * @buf         buffer to which the device path is wirtten
 782  * @desc        block device descriptor
 783  * @part        partition number, 0 identifies a block device
 784  */
 785 struct efi_device_path *efi_dp_part_node(struct blk_desc *desc, int part)
 786 {
 787         efi_uintn_t dpsize;
 788         void *buf;
 789
 790         if (desc->part_type == PART_TYPE_ISO)
 791                 dpsize = sizeof(struct efi_device_path_cdrom_path);
 792         else
 793                 dpsize = sizeof(struct efi_device_path_hard_drive_path);
 794         buf = dp_alloc(dpsize);
 795
 796         dp_part_node(buf, desc, part);
 797
 798         return buf;
 799 }
 800
 801 /* convert path to an UEFI style path (ie. DOS style backslashes and utf16) */
 802 static void path_to_uefi(u16 *uefi, const char *path)
 803 {
 804         while (*path) {
 805                 char c = *(path++);
 806                 if (c == '/')
 807                         c = '\\';
 808                 *(uefi++) = c;
 809         }
 810         *uefi = '\0';
 811 }
 812
 813 /*
 814  * If desc is NULL, this creates a path with only the file component,
 815  * otherwise it creates a full path with both device and file components
 816  */
 817 struct efi_device_path *efi_dp_from_file(struct blk_desc *desc, int part,
 818                 const char *path)
 819 {
 820         struct efi_device_path_file_path *fp;
 821         void *buf, *start;
 822         unsigned dpsize = 0, fpsize;
 823
 824         if (desc)
 825                 dpsize = dp_part_size(desc, part);
 826
 827         fpsize = sizeof(struct efi_device_path) + 2 * (strlen(path) + 1);
 828         dpsize += fpsize;
 829
 830         start = buf = dp_alloc(dpsize + sizeof(END));
 831         if (!buf)
 832                 return NULL;
 833
 834         if (desc)
 835                 buf = dp_part_fill(buf, desc, part);
 836
 837         /* add file-path: */
 838         fp = buf;
 839         fp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 840         fp->dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
 841         fp->dp.length = fpsize;
 842         path_to_uefi(fp->str, path);
 843         buf += fpsize;
 844
 845         *((struct efi_device_path *)buf) = END;
 846
 847         return start;
 848 }
 849
 850 #ifdef CONFIG_NET
 851 struct efi_device_path *efi_dp_from_eth(void)
 852 {
 853 #ifndef CONFIG_DM_ETH
 854         struct efi_device_path_mac_addr *ndp;
 855 #endif
 856         void *buf, *start;
 857         unsigned dpsize = 0;
 858
 859         assert(eth_get_dev());
 860
 861 #ifdef CONFIG_DM_ETH
 862         dpsize += dp_size(eth_get_dev());
 863 #else
 864         dpsize += sizeof(ROOT);
 865         dpsize += sizeof(*ndp);
 866 #endif
 867
 868         start = buf = dp_alloc(dpsize + sizeof(END));
 869         if (!buf)
 870                 return NULL;
 871
 872 #ifdef CONFIG_DM_ETH
 873         buf = dp_fill(buf, eth_get_dev());
 874 #else
 875         memcpy(buf, &ROOT, sizeof(ROOT));
 876         buf += sizeof(ROOT);
 877
 878         ndp = buf;
 879         ndp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 880         ndp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
 881         ndp->dp.length = sizeof(*ndp);
 882         ndp->if_type = 1; /* Ethernet */
 883         memcpy(ndp->mac.addr, eth_get_ethaddr(), ARP_HLEN);
 884         buf = &ndp[1];
 885 #endif
 886
 887         *((struct efi_device_path *)buf) = END;
 888
 889         return start;
 890 }
 891 #endif
 892
 893 /* Construct a device-path for memory-mapped image */
 894 struct efi_device_path *efi_dp_from_mem(uint32_t memory_type,
 895                                         uint64_t start_address,
 896                                         uint64_t end_address)
 897 {
 898         struct efi_device_path_memory *mdp;
 899         void *buf, *start;
 900
 901         start = buf = dp_alloc(sizeof(*mdp) + sizeof(END));
 902         if (!buf)
 903                 return NULL;
 904
 905         mdp = buf;
 906         mdp->dp.type = DEVICE_PATH_TYPE_HARDWARE_DEVICE;
 907         mdp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MEMORY;
 908         mdp->dp.length = sizeof(*mdp);
 909         mdp->memory_type = memory_type;
 910         mdp->start_address = start_address;
 911         mdp->end_address = end_address;
 912         buf = &mdp[1];
 913
 914         *((struct efi_device_path *)buf) = END;
 915
 916         return start;
 917 }
 918
 919 /*
 920  * Helper to split a full device path (containing both device and file
 921  * parts) into it's constituent parts.
 922  */
 923 efi_status_t efi_dp_split_file_path(struct efi_device_path *full_path,
 924                                     struct efi_device_path **device_path,
 925                                     struct efi_device_path **file_path)
 926 {
 927         struct efi_device_path *p, *dp, *fp;
 928
 929         *device_path = NULL;
 930         *file_path = NULL;
 931         dp = efi_dp_dup(full_path);
 932         if (!dp)
 933                 return EFI_OUT_OF_RESOURCES;
 934         p = dp;
 935         while (!EFI_DP_TYPE(p, MEDIA_DEVICE, FILE_PATH)) {
 936                 p = efi_dp_next(p);
 937                 if (!p)
 938                         return EFI_OUT_OF_RESOURCES;
 939         }
 940         fp = efi_dp_dup(p);
 941         if (!fp)
 942                 return EFI_OUT_OF_RESOURCES;
 943         p->type = DEVICE_PATH_TYPE_END;
 944         p->sub_type = DEVICE_PATH_SUB_TYPE_END;
 945         p->length = sizeof(*p);
 946
 947         *device_path = dp;
 948         *file_path = fp;
 949         return EFI_SUCCESS;
 950 }