git.sur5r.net Git - u-boot/blob - 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 #include <common.h>
  10 #include <blk.h>
  11 #include <dm.h>
  12 #include <usb.h>
  13 #include <mmc.h>
  14 #include <efi_loader.h>
  15 #include <inttypes.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 static void *dp_alloc(size_t sz)
  40 {
  41         void *buf;
  42
  43         if (efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, sz, &buf) != EFI_SUCCESS)
  44                 return NULL;
  45
  46         return buf;
  47 }
  48
  49 /*
  50  * Iterate to next block in device-path, terminating (returning NULL)
  51  * at /End* node.
  52  */
  53 struct efi_device_path *efi_dp_next(const struct efi_device_path *dp)
  54 {
  55         if (dp == NULL)
  56                 return NULL;
  57         if (dp->type == DEVICE_PATH_TYPE_END)
  58                 return NULL;
  59         dp = ((void *)dp) + dp->length;
  60         if (dp->type == DEVICE_PATH_TYPE_END)
  61                 return NULL;
  62         return (struct efi_device_path *)dp;
  63 }
  64
  65 /*
  66  * Compare two device-paths, stopping when the shorter of the two hits
  67  * an End* node.  This is useful to, for example, compare a device-path
  68  * representing a device with one representing a file on the device, or
  69  * a device with a parent device.
  70  */
  71 int efi_dp_match(struct efi_device_path *a, struct efi_device_path *b)
  72 {
  73         while (1) {
  74                 int ret;
  75
  76                 ret = memcmp(&a->length, &b->length, sizeof(a->length));
  77                 if (ret)
  78                         return ret;
  79
  80                 ret = memcmp(a, b, a->length);
  81                 if (ret)
  82                         return ret;
  83
  84                 a = efi_dp_next(a);
  85                 b = efi_dp_next(b);
  86
  87                 if (!a || !b)
  88                         return 0;
  89         }
  90 }
  91
  92
  93 /*
  94  * See UEFI spec (section 3.1.2, about short-form device-paths..
  95  * tl;dr: we can have a device-path that starts with a USB WWID
  96  * or USB Class node, and a few other cases which don't encode
  97  * the full device path with bus hierarchy:
  98  *
  99  *   - MESSAGING:USB_WWID
 100  *   - MESSAGING:USB_CLASS
 101  *   - MEDIA:FILE_PATH
 102  *   - MEDIA:HARD_DRIVE
 103  *   - MESSAGING:URI
 104  */
 105 static struct efi_device_path *shorten_path(struct efi_device_path *dp)
 106 {
 107         while (dp) {
 108                 /*
 109                  * TODO: Add MESSAGING:USB_WWID and MESSAGING:URI..
 110                  * in practice fallback.efi just uses MEDIA:HARD_DRIVE
 111                  * so not sure when we would see these other cases.
 112                  */
 113                 if (EFI_DP_TYPE(dp, MESSAGING_DEVICE, MSG_USB_CLASS) ||
 114                     EFI_DP_TYPE(dp, MEDIA_DEVICE, HARD_DRIVE_PATH) ||
 115                     EFI_DP_TYPE(dp, MEDIA_DEVICE, FILE_PATH))
 116                         return dp;
 117
 118                 dp = efi_dp_next(dp);
 119         }
 120
 121         return dp;
 122 }
 123
 124 static struct efi_object *find_obj(struct efi_device_path *dp, bool short_path,
 125                                    struct efi_device_path **rem)
 126 {
 127         struct efi_object *efiobj;
 128
 129         list_for_each_entry(efiobj, &efi_obj_list, link) {
 130                 int i;
 131
 132                 for (i = 0; i < ARRAY_SIZE(efiobj->protocols); i++) {
 133                         struct efi_handler *handler = &efiobj->protocols[i];
 134                         struct efi_device_path *obj_dp;
 135
 136                         if (!handler->guid)
 137                                 break;
 138
 139                         if (guidcmp(handler->guid, &efi_guid_device_path))
 140                                 continue;
 141
 142                         obj_dp = handler->protocol_interface;
 143
 144                         do {
 145                                 if (efi_dp_match(dp, obj_dp) == 0) {
 146                                         if (rem) {
 147                                                 *rem = ((void *)dp) +
 148                                                         efi_dp_size(obj_dp);
 149                                         }
 150                                         return efiobj;
 151                                 }
 152
 153                                 obj_dp = shorten_path(efi_dp_next(obj_dp));
 154                         } while (short_path && obj_dp);
 155                 }
 156         }
 157
 158         return NULL;
 159 }
 160
 161
 162 /*
 163  * Find an efiobj from device-path, if 'rem' is not NULL, returns the
 164  * remaining part of the device path after the matched object.
 165  */
 166 struct efi_object *efi_dp_find_obj(struct efi_device_path *dp,
 167                                    struct efi_device_path **rem)
 168 {
 169         struct efi_object *efiobj;
 170
 171         efiobj = find_obj(dp, false, rem);
 172
 173         if (!efiobj)
 174                 efiobj = find_obj(dp, true, rem);
 175
 176         return efiobj;
 177 }
 178
 179 /* return size not including End node: */
 180 unsigned efi_dp_size(const struct efi_device_path *dp)
 181 {
 182         unsigned sz = 0;
 183
 184         while (dp) {
 185                 sz += dp->length;
 186                 dp = efi_dp_next(dp);
 187         }
 188
 189         return sz;
 190 }
 191
 192 struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp)
 193 {
 194         struct efi_device_path *ndp;
 195         unsigned sz = efi_dp_size(dp) + sizeof(END);
 196
 197         if (!dp)
 198                 return NULL;
 199
 200         ndp = dp_alloc(sz);
 201         memcpy(ndp, dp, sz);
 202
 203         return ndp;
 204 }
 205
 206 struct efi_device_path *efi_dp_append(const struct efi_device_path *dp1,
 207                                       const struct efi_device_path *dp2)
 208 {
 209         struct efi_device_path *ret;
 210
 211         if (!dp1) {
 212                 ret = efi_dp_dup(dp2);
 213         } else if (!dp2) {
 214                 ret = efi_dp_dup(dp1);
 215         } else {
 216                 /* both dp1 and dp2 are non-null */
 217                 unsigned sz1 = efi_dp_size(dp1);
 218                 unsigned sz2 = efi_dp_size(dp2);
 219                 void *p = dp_alloc(sz1 + sz2 + sizeof(END));
 220                 memcpy(p, dp1, sz1);
 221                 memcpy(p + sz1, dp2, sz2);
 222                 memcpy(p + sz1 + sz2, &END, sizeof(END));
 223                 ret = p;
 224         }
 225
 226         return ret;
 227 }
 228
 229 struct efi_device_path *efi_dp_append_node(const struct efi_device_path *dp,
 230                                            const struct efi_device_path *node)
 231 {
 232         struct efi_device_path *ret;
 233
 234         if (!node && !dp) {
 235                 ret = efi_dp_dup(&END);
 236         } else if (!node) {
 237                 ret = efi_dp_dup(dp);
 238         } else if (!dp) {
 239                 unsigned sz = node->length;
 240                 void *p = dp_alloc(sz + sizeof(END));
 241                 memcpy(p, node, sz);
 242                 memcpy(p + sz, &END, sizeof(END));
 243                 ret = p;
 244         } else {
 245                 /* both dp and node are non-null */
 246                 unsigned sz = efi_dp_size(dp);
 247                 void *p = dp_alloc(sz + node->length + sizeof(END));
 248                 memcpy(p, dp, sz);
 249                 memcpy(p + sz, node, node->length);
 250                 memcpy(p + sz + node->length, &END, sizeof(END));
 251                 ret = p;
 252         }
 253
 254         return ret;
 255 }
 256
 257 #ifdef CONFIG_DM
 258 /* size of device-path not including END node for device and all parents
 259  * up to the root device.
 260  */
 261 static unsigned dp_size(struct udevice *dev)
 262 {
 263         if (!dev || !dev->driver)
 264                 return sizeof(ROOT);
 265
 266         switch (dev->driver->id) {
 267         case UCLASS_ROOT:
 268         case UCLASS_SIMPLE_BUS:
 269                 /* stop traversing parents at this point: */
 270                 return sizeof(ROOT);
 271         case UCLASS_MMC:
 272                 return dp_size(dev->parent) +
 273                         sizeof(struct efi_device_path_sd_mmc_path);
 274         case UCLASS_MASS_STORAGE:
 275         case UCLASS_USB_HUB:
 276                 return dp_size(dev->parent) +
 277                         sizeof(struct efi_device_path_usb_class);
 278         default:
 279                 /* just skip over unknown classes: */
 280                 return dp_size(dev->parent);
 281         }
 282 }
 283
 284 static void *dp_fill(void *buf, struct udevice *dev)
 285 {
 286         if (!dev || !dev->driver)
 287                 return buf;
 288
 289         switch (dev->driver->id) {
 290         case UCLASS_ROOT:
 291         case UCLASS_SIMPLE_BUS: {
 292                 /* stop traversing parents at this point: */
 293                 struct efi_device_path_vendor *vdp = buf;
 294                 *vdp = ROOT;
 295                 return &vdp[1];
 296         }
 297 #if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC)
 298         case UCLASS_MMC: {
 299                 struct efi_device_path_sd_mmc_path *sddp =
 300                         dp_fill(buf, dev->parent);
 301                 struct mmc *mmc = mmc_get_mmc_dev(dev);
 302                 struct blk_desc *desc = mmc_get_blk_desc(mmc);
 303
 304                 sddp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 305                 sddp->dp.sub_type = (desc->if_type == IF_TYPE_MMC) ?
 306                         DEVICE_PATH_SUB_TYPE_MSG_MMC :
 307                         DEVICE_PATH_SUB_TYPE_MSG_SD;
 308                 sddp->dp.length   = sizeof(*sddp);
 309                 sddp->slot_number = dev->seq;
 310
 311                 return &sddp[1];
 312         }
 313 #endif
 314         case UCLASS_MASS_STORAGE:
 315         case UCLASS_USB_HUB: {
 316                 struct efi_device_path_usb_class *udp =
 317                         dp_fill(buf, dev->parent);
 318                 struct usb_device *udev = dev_get_parent_priv(dev);
 319                 struct usb_device_descriptor *desc = &udev->descriptor;
 320
 321                 udp->dp.type     = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 322                 udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS;
 323                 udp->dp.length   = sizeof(*udp);
 324                 udp->vendor_id   = desc->idVendor;
 325                 udp->product_id  = desc->idProduct;
 326                 udp->device_class    = desc->bDeviceClass;
 327                 udp->device_subclass = desc->bDeviceSubClass;
 328                 udp->device_protocol = desc->bDeviceProtocol;
 329
 330                 return &udp[1];
 331         }
 332         default:
 333                 debug("unhandled device class: %s (%u)\n",
 334                       dev->name, dev->driver->id);
 335                 return dp_fill(buf, dev->parent);
 336         }
 337 }
 338
 339 /* Construct a device-path from a device: */
 340 struct efi_device_path *efi_dp_from_dev(struct udevice *dev)
 341 {
 342         void *buf, *start;
 343
 344         start = buf = dp_alloc(dp_size(dev) + sizeof(END));
 345         buf = dp_fill(buf, dev);
 346         *((struct efi_device_path *)buf) = END;
 347
 348         return start;
 349 }
 350 #endif
 351
 352 static unsigned dp_part_size(struct blk_desc *desc, int part)
 353 {
 354         unsigned dpsize;
 355
 356 #ifdef CONFIG_BLK
 357         dpsize = dp_size(desc->bdev->parent);
 358 #else
 359         dpsize = sizeof(ROOT) + sizeof(struct efi_device_path_usb);
 360 #endif
 361
 362         if (part == 0) /* the actual disk, not a partition */
 363                 return dpsize;
 364
 365         if (desc->part_type == PART_TYPE_ISO)
 366                 dpsize += sizeof(struct efi_device_path_cdrom_path);
 367         else
 368                 dpsize += sizeof(struct efi_device_path_hard_drive_path);
 369
 370         return dpsize;
 371 }
 372
 373 static void *dp_part_fill(void *buf, struct blk_desc *desc, int part)
 374 {
 375         disk_partition_t info;
 376
 377 #ifdef CONFIG_BLK
 378         buf = dp_fill(buf, desc->bdev->parent);
 379 #else
 380         /*
 381          * We *could* make a more accurate path, by looking at if_type
 382          * and handling all the different cases like we do for non-
 383          * legacy (ie CONFIG_BLK=y) case.  But most important thing
 384          * is just to have a unique device-path for if_type+devnum.
 385          * So map things to a fictional USB device:
 386          */
 387         struct efi_device_path_usb *udp;
 388
 389         memcpy(buf, &ROOT, sizeof(ROOT));
 390         buf += sizeof(ROOT);
 391
 392         udp = buf;
 393         udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 394         udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB;
 395         udp->dp.length = sizeof(*udp);
 396         udp->parent_port_number = desc->if_type;
 397         udp->usb_interface = desc->devnum;
 398         buf = &udp[1];
 399 #endif
 400
 401         if (part == 0) /* the actual disk, not a partition */
 402                 return buf;
 403
 404         part_get_info(desc, part, &info);
 405
 406         if (desc->part_type == PART_TYPE_ISO) {
 407                 struct efi_device_path_cdrom_path *cddp = buf;
 408
 409                 cddp->boot_entry = part - 1;
 410                 cddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 411                 cddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_CDROM_PATH;
 412                 cddp->dp.length = sizeof(*cddp);
 413                 cddp->partition_start = info.start;
 414                 cddp->partition_end = info.size;
 415
 416                 buf = &cddp[1];
 417         } else {
 418                 struct efi_device_path_hard_drive_path *hddp = buf;
 419
 420                 hddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 421                 hddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH;
 422                 hddp->dp.length = sizeof(*hddp);
 423                 hddp->partition_number = part - 1;
 424                 hddp->partition_start = info.start;
 425                 hddp->partition_end = info.size;
 426                 if (desc->part_type == PART_TYPE_EFI)
 427                         hddp->partmap_type = 2;
 428                 else
 429                         hddp->partmap_type = 1;
 430                 hddp->signature_type = desc->sig_type;
 431                 if (hddp->signature_type != 0)
 432                         memcpy(hddp->partition_signature, &desc->guid_sig,
 433                                sizeof(hddp->partition_signature));
 434
 435                 buf = &hddp[1];
 436         }
 437
 438         return buf;
 439 }
 440
 441
 442 /* Construct a device-path from a partition on a blk device: */
 443 struct efi_device_path *efi_dp_from_part(struct blk_desc *desc, int part)
 444 {
 445         void *buf, *start;
 446
 447         start = buf = dp_alloc(dp_part_size(desc, part) + sizeof(END));
 448
 449         buf = dp_part_fill(buf, desc, part);
 450
 451         *((struct efi_device_path *)buf) = END;
 452
 453         return start;
 454 }
 455
 456 /* convert path to an UEFI style path (ie. DOS style backslashes and utf16) */
 457 static void path_to_uefi(u16 *uefi, const char *path)
 458 {
 459         while (*path) {
 460                 char c = *(path++);
 461                 if (c == '/')
 462                         c = '\\';
 463                 *(uefi++) = c;
 464         }
 465         *uefi = '\0';
 466 }
 467
 468 /*
 469  * If desc is NULL, this creates a path with only the file component,
 470  * otherwise it creates a full path with both device and file components
 471  */
 472 struct efi_device_path *efi_dp_from_file(struct blk_desc *desc, int part,
 473                 const char *path)
 474 {
 475         struct efi_device_path_file_path *fp;
 476         void *buf, *start;
 477         unsigned dpsize = 0, fpsize;
 478
 479         if (desc)
 480                 dpsize = dp_part_size(desc, part);
 481
 482         fpsize = sizeof(struct efi_device_path) + 2 * (strlen(path) + 1);
 483         dpsize += fpsize;
 484
 485         start = buf = dp_alloc(dpsize + sizeof(END));
 486
 487         if (desc)
 488                 buf = dp_part_fill(buf, desc, part);
 489
 490         /* add file-path: */
 491         fp = buf;
 492         fp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 493         fp->dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
 494         fp->dp.length = fpsize;
 495         path_to_uefi(fp->str, path);
 496         buf += fpsize;
 497
 498         *((struct efi_device_path *)buf) = END;
 499
 500         return start;
 501 }
 502
 503 #ifdef CONFIG_NET
 504 struct efi_device_path *efi_dp_from_eth(void)
 505 {
 506         struct efi_device_path_mac_addr *ndp;
 507         void *buf, *start;
 508         unsigned dpsize = 0;
 509
 510         assert(eth_get_dev());
 511
 512 #ifdef CONFIG_DM_ETH
 513         dpsize += dp_size(eth_get_dev());
 514 #else
 515         dpsize += sizeof(ROOT);
 516 #endif
 517         dpsize += sizeof(*ndp);
 518
 519         start = buf = dp_alloc(dpsize + sizeof(END));
 520
 521 #ifdef CONFIG_DM_ETH
 522         buf = dp_fill(buf, eth_get_dev());
 523 #else
 524         memcpy(buf, &ROOT, sizeof(ROOT));
 525         buf += sizeof(ROOT);
 526 #endif
 527
 528         ndp = buf;
 529         ndp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 530         ndp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
 531         ndp->dp.length = sizeof(*ndp);
 532         memcpy(ndp->mac.addr, eth_get_ethaddr(), ARP_HLEN);
 533         buf = &ndp[1];
 534
 535         *((struct efi_device_path *)buf) = END;
 536
 537         return start;
 538 }
 539 #endif
 540
 541 /* Construct a device-path for memory-mapped image */
 542 struct efi_device_path *efi_dp_from_mem(uint32_t memory_type,
 543                                         uint64_t start_address,
 544                                         uint64_t end_address)
 545 {
 546         struct efi_device_path_memory *mdp;
 547         void *buf, *start;
 548
 549         start = buf = dp_alloc(sizeof(*mdp) + sizeof(END));
 550
 551         mdp = buf;
 552         mdp->dp.type = DEVICE_PATH_TYPE_HARDWARE_DEVICE;
 553         mdp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MEMORY;
 554         mdp->dp.length = sizeof(*mdp);
 555         mdp->memory_type = memory_type;
 556         mdp->start_address = start_address;
 557         mdp->end_address = end_address;
 558         buf = &mdp[1];
 559
 560         *((struct efi_device_path *)buf) = END;
 561
 562         return start;
 563 }
 564
 565 /*
 566  * Helper to split a full device path (containing both device and file
 567  * parts) into it's constituent parts.
 568  */
 569 void efi_dp_split_file_path(struct efi_device_path *full_path,
 570                             struct efi_device_path **device_path,
 571                             struct efi_device_path **file_path)
 572 {
 573         struct efi_device_path *p, *dp, *fp;
 574
 575         dp = efi_dp_dup(full_path);
 576         p = dp;
 577         while (!EFI_DP_TYPE(p, MEDIA_DEVICE, FILE_PATH))
 578                 p = efi_dp_next(p);
 579         fp = efi_dp_dup(p);
 580
 581         p->type = DEVICE_PATH_TYPE_END;
 582         p->sub_type = DEVICE_PATH_SUB_TYPE_END;
 583         p->length = sizeof(*p);
 584
 585         *device_path = dp;
 586         *file_path = fp;
 587 }