src/lib/cbfs.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <assert.h>
   4 #include <boot_device.h>
   5 #include <cbfs.h>
   6 #include <cbmem.h>
   7 #include <commonlib/bsd/cbfs_private.h>
   8 #include <commonlib/bsd/compression.h>
   9 #include <console/console.h>
  10 #include <fmap.h>
  11 #include <lib.h>
  12 #include <list.h>
  13 #include <metadata_hash.h>
  14 #include <security/tpm/tspi/crtm.h>
  15 #include <security/vboot/misc.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include <symbols.h>
  19 #include <thread.h>
  20 #include <timestamp.h>
  21
  22 #if ENV_HAS_DATA_SECTION
  23 struct mem_pool cbfs_cache =
  24         MEM_POOL_INIT(_cbfs_cache, REGION_SIZE(cbfs_cache), CONFIG_CBFS_CACHE_ALIGN);
  25 #else
  26 struct mem_pool cbfs_cache = MEM_POOL_INIT(NULL, 0, 0);
  27 #endif
  28
  29 static void switch_to_postram_cache(int unused)
  30 {
  31         if (_preram_cbfs_cache != _postram_cbfs_cache)
  32                 mem_pool_init(&cbfs_cache, _postram_cbfs_cache, REGION_SIZE(postram_cbfs_cache),
  33                               CONFIG_CBFS_CACHE_ALIGN);
  34 }
  35 CBMEM_CREATION_HOOK(switch_to_postram_cache);
  36
  37 enum cb_err _cbfs_boot_lookup(const char *name, bool force_ro,
  38                               union cbfs_mdata *mdata, struct region_device *rdev)
  39 {
  40         const struct cbfs_boot_device *cbd = cbfs_get_boot_device(force_ro);
  41         if (!cbd)
  42                 return CB_ERR;
  43
  44         size_t data_offset;
  45         enum cb_err err = CB_CBFS_CACHE_FULL;
  46         if (!CONFIG(NO_CBFS_MCACHE) && !ENV_SMM && cbd->mcache_size)
  47                 err = cbfs_mcache_lookup(cbd->mcache, cbd->mcache_size,
  48                                          name, mdata, &data_offset);
  49         if (err == CB_CBFS_CACHE_FULL) {
  50                 struct vb2_hash *metadata_hash = NULL;
  51                 if (CONFIG(TOCTOU_SAFETY)) {
  52                         if (ENV_SMM)  /* Cannot provide TOCTOU safety for SMM */
  53                                 dead_code();
  54                         if (!cbd->mcache_size)
  55                                 die("Cannot access CBFS TOCTOU-safely in " ENV_STRING " before CBMEM init!\n");
  56                         /* We can only reach this for the RW CBFS -- an mcache overflow in the
  57                            RO CBFS would have been caught when building the mcache in cbfs_get
  58                            boot_device(). (Note that TOCTOU_SAFETY implies !NO_CBFS_MCACHE.) */
  59                         assert(cbd == vboot_get_cbfs_boot_device());
  60                         die("TODO: set metadata_hash to RW metadata hash here.\n");
  61                 }
  62                 err = cbfs_lookup(&cbd->rdev, name, mdata, &data_offset, metadata_hash);
  63         }
  64
  65         if (CONFIG(VBOOT_ENABLE_CBFS_FALLBACK) && !force_ro && err == CB_CBFS_NOT_FOUND) {
  66                 printk(BIOS_INFO, "CBFS: Fall back to RO region for %s\n", name);
  67                 return _cbfs_boot_lookup(name, true, mdata, rdev);
  68         }
  69         if (err) {
  70                 if (err == CB_CBFS_NOT_FOUND)
  71                         printk(BIOS_WARNING, "CBFS: '%s' not found.\n", name);
  72                 else if (err == CB_CBFS_HASH_MISMATCH)
  73                         printk(BIOS_ERR, "CBFS ERROR: metadata hash mismatch!\n");
  74                 else
  75                         printk(BIOS_ERR, "CBFS ERROR: error %d when looking up '%s'\n",
  76                                err, name);
  77                 return err;
  78         }
  79
  80         if (rdev_chain(rdev, &cbd->rdev, data_offset, be32toh(mdata->h.len)))
  81                 return CB_ERR;
  82
  83         return CB_SUCCESS;
  84 }
  85
  86 void cbfs_unmap(void *mapping)
  87 {
  88         /*
  89          * This is save to call with mappings that weren't allocated in the cache (e.g. x86
  90          * direct mappings) -- mem_pool_free() just does nothing for addresses it doesn't
  91          * recognize. This hardcodes the assumption that if platforms implement an rdev_mmap()
  92          * that requires a free() for the boot_device, they need to implement it via the
  93          * cbfs_cache mem_pool.
  94          */
  95         mem_pool_free(&cbfs_cache, mapping);
  96 }
  97
  98 static inline bool fsps_env(void)
  99 {
 100         /* FSP-S is assumed to be loaded in ramstage. */
 101         if (ENV_RAMSTAGE)
 102                 return true;
 103         return false;
 104 }
 105
 106 static inline bool fspm_env(void)
 107 {
 108         /* FSP-M is assumed to be loaded in romstage. */
 109         if (ENV_RAMINIT)
 110                 return true;
 111         return false;
 112 }
 113
 114 static inline bool cbfs_lz4_enabled(void)
 115 {
 116         if (fsps_env() && CONFIG(FSP_COMPRESS_FSP_S_LZ4))
 117                 return true;
 118         if (fspm_env() && CONFIG(FSP_COMPRESS_FSP_M_LZ4))
 119                 return true;
 120
 121         if ((ENV_BOOTBLOCK || ENV_SEPARATE_VERSTAGE) && !CONFIG(COMPRESS_PRERAM_STAGES))
 122                 return false;
 123
 124         if (ENV_SMM)
 125                 return false;
 126
 127         return true;
 128 }
 129
 130 static inline bool cbfs_lzma_enabled(void)
 131 {
 132         if (fsps_env() && CONFIG(FSP_COMPRESS_FSP_S_LZMA))
 133                 return true;
 134         if (fspm_env() && CONFIG(FSP_COMPRESS_FSP_M_LZMA))
 135                 return true;
 136         /* We assume here romstage and postcar are never compressed. */
 137         if (ENV_BOOTBLOCK || ENV_SEPARATE_VERSTAGE)
 138                 return false;
 139         if (ENV_ROMSTAGE && CONFIG(POSTCAR_STAGE))
 140                 return false;
 141         if ((ENV_ROMSTAGE || ENV_POSTCAR) && !CONFIG(COMPRESS_RAMSTAGE))
 142                 return false;
 143         if (ENV_SMM)
 144                 return false;
 145         return true;
 146 }
 147
 148 static bool cbfs_file_hash_mismatch(const void *buffer, size_t size,
 149                                     const union cbfs_mdata *mdata, bool skip_verification)
 150 {
 151         /* Avoid linking hash functions when verification and measurement are disabled. */
 152         if (!CONFIG(CBFS_VERIFICATION) && !CONFIG(TPM_MEASURED_BOOT))
 153                 return false;
 154
 155         const struct vb2_hash *hash = NULL;
 156
 157         if (CONFIG(CBFS_VERIFICATION) && !skip_verification) {
 158                 hash = cbfs_file_hash(mdata);
 159                 if (!hash) {
 160                         ERROR("'%s' does not have a file hash!\n", mdata->h.filename);
 161                         return true;
 162                 }
 163                 if (vb2_hash_verify(vboot_hwcrypto_allowed(), buffer, size, hash)) {
 164                         ERROR("'%s' file hash mismatch!\n", mdata->h.filename);
 165                         return true;
 166                 }
 167         }
 168
 169         if (CONFIG(TPM_MEASURED_BOOT) && !ENV_SMM) {
 170                 struct vb2_hash calculated_hash;
 171
 172                 /* No need to re-hash file if we already have it from verification. */
 173                 if (!hash || hash->algo != TPM_MEASURE_ALGO) {
 174                         if (vb2_hash_calculate(vboot_hwcrypto_allowed(), buffer, size,
 175                                                TPM_MEASURE_ALGO, &calculated_hash))
 176                                 hash = NULL;
 177                         else
 178                                 hash = &calculated_hash;
 179                 }
 180
 181                 if (!hash ||
 182                     tspi_cbfs_measurement(mdata->h.filename, be32toh(mdata->h.type), hash))
 183                         ERROR("failed to measure '%s' into TCPA log\n", mdata->h.filename);
 184                         /* We intentionally continue to boot on measurement errors. */
 185         }
 186
 187         return false;
 188 }
 189
 190 static size_t cbfs_load_and_decompress(const struct region_device *rdev, void *buffer,
 191                                        size_t buffer_size, uint32_t compression,
 192                                        const union cbfs_mdata *mdata, bool skip_verification)
 193 {
 194         size_t in_size = region_device_sz(rdev);
 195         size_t out_size = 0;
 196         void *map;
 197
 198         DEBUG("Decompressing %zu bytes from '%s' to %p with algo %d\n",
 199               in_size, mdata->h.filename, buffer, compression);
 200
 201         switch (compression) {
 202         case CBFS_COMPRESS_NONE:
 203                 if (buffer_size < in_size)
 204                         return 0;
 205                 if (rdev_readat(rdev, buffer, 0, in_size) != in_size)
 206                         return 0;
 207                 if (cbfs_file_hash_mismatch(buffer, in_size, mdata, skip_verification))
 208                         return 0;
 209                 return in_size;
 210
 211         case CBFS_COMPRESS_LZ4:
 212                 if (!cbfs_lz4_enabled())
 213                         return 0;
 214
 215                 /* cbfs_prog_stage_load() takes care of in-place LZ4 decompression by
 216                    setting up the rdev to be in memory. */
 217                 map = rdev_mmap_full(rdev);
 218                 if (map == NULL)
 219                         return 0;
 220
 221                 if (!cbfs_file_hash_mismatch(map, in_size, mdata, skip_verification)) {
 222                         timestamp_add_now(TS_ULZ4F_START);
 223                         out_size = ulz4fn(map, in_size, buffer, buffer_size);
 224                         timestamp_add_now(TS_ULZ4F_END);
 225                 }
 226
 227                 rdev_munmap(rdev, map);
 228
 229                 return out_size;
 230
 231         case CBFS_COMPRESS_LZMA:
 232                 if (!cbfs_lzma_enabled())
 233                         return 0;
 234                 map = rdev_mmap_full(rdev);
 235                 if (map == NULL)
 236                         return 0;
 237
 238                 if (!cbfs_file_hash_mismatch(map, in_size, mdata, skip_verification)) {
 239                         /* Note: timestamp not useful for memory-mapped media (x86) */
 240                         timestamp_add_now(TS_ULZMA_START);
 241                         out_size = ulzman(map, in_size, buffer, buffer_size);
 242                         timestamp_add_now(TS_ULZMA_END);
 243                 }
 244
 245                 rdev_munmap(rdev, map);
 246
 247                 return out_size;
 248
 249         default:
 250                 return 0;
 251         }
 252 }
 253
 254 struct cbfs_preload_context {
 255         struct region_device rdev;
 256         struct thread_handle handle;
 257         struct list_node list_node;
 258         void *buffer;
 259         char name[];
 260 };
 261
 262 static struct list_node cbfs_preload_context_list;
 263
 264 static struct cbfs_preload_context *alloc_cbfs_preload_context(size_t additional)
 265 {
 266         struct cbfs_preload_context *context;
 267         size_t size = sizeof(*context) + additional;
 268
 269         context = mem_pool_alloc(&cbfs_cache, size);
 270
 271         if (!context)
 272                 return NULL;
 273
 274         memset(context, 0, size);
 275
 276         return context;
 277 }
 278
 279 static void append_cbfs_preload_context(struct cbfs_preload_context *context)
 280 {
 281         list_append(&context->list_node, &cbfs_preload_context_list);
 282 }
 283
 284 static void free_cbfs_preload_context(struct cbfs_preload_context *context)
 285 {
 286         list_remove(&context->list_node);
 287
 288         mem_pool_free(&cbfs_cache, context);
 289 }
 290
 291 static enum cb_err cbfs_preload_thread_entry(void *arg)
 292 {
 293         struct cbfs_preload_context *context = arg;
 294
 295         if (rdev_read_full(&context->rdev, context->buffer) < 0) {
 296                 ERROR("%s(name='%s') readat failed\n", __func__, context->name);
 297                 return CB_ERR;
 298         }
 299
 300         return CB_SUCCESS;
 301 }
 302
 303 void cbfs_preload(const char *name)
 304 {
 305         struct region_device rdev;
 306         union cbfs_mdata mdata;
 307         struct cbfs_preload_context *context;
 308         bool force_ro = false;
 309         size_t size;
 310
 311         if (!CONFIG(CBFS_PRELOAD))
 312                 dead_code();
 313
 314         /* We don't want to cross the vboot boundary */
 315         if (ENV_ROMSTAGE && CONFIG(VBOOT_STARTS_IN_ROMSTAGE))
 316                 return;
 317
 318         DEBUG("%s(name='%s')\n", __func__, name);
 319
 320         if (_cbfs_boot_lookup(name, force_ro, &mdata, &rdev))
 321                 return;
 322
 323         size = region_device_sz(&rdev);
 324
 325         context = alloc_cbfs_preload_context(strlen(name) + 1);
 326         if (!context) {
 327                 ERROR("%s(name='%s') failed to allocate preload context\n", __func__, name);
 328                 return;
 329         }
 330
 331         context->buffer = mem_pool_alloc(&cbfs_cache, size);
 332         if (context->buffer == NULL) {
 333                 ERROR("%s(name='%s') failed to allocate %zu bytes for preload buffer\n",
 334                       __func__, name, size);
 335                 goto out;
 336         }
 337
 338         context->rdev = rdev;
 339         strcpy(context->name, name);
 340
 341         append_cbfs_preload_context(context);
 342
 343         if (thread_run(&context->handle, cbfs_preload_thread_entry, context) == 0)
 344                 return;
 345
 346         ERROR("%s(name='%s') failed to start preload thread\n", __func__, name);
 347         mem_pool_free(&cbfs_cache, context->buffer);
 348
 349 out:
 350         free_cbfs_preload_context(context);
 351 }
 352
 353 static struct cbfs_preload_context *find_cbfs_preload_context(const char *name)
 354 {
 355         struct cbfs_preload_context *context;
 356
 357         list_for_each(context, cbfs_preload_context_list, list_node) {
 358                 if (strcmp(context->name, name) == 0)
 359                         return context;
 360         }
 361
 362         return NULL;
 363 }
 364
 365 static enum cb_err get_preload_rdev(struct region_device *rdev, const char *name)
 366 {
 367         enum cb_err err;
 368         struct cbfs_preload_context *context;
 369
 370         if (!CONFIG(CBFS_PRELOAD) || !ENV_SUPPORTS_COOP)
 371                 return CB_ERR_ARG;
 372
 373         context = find_cbfs_preload_context(name);
 374         if (!context)
 375                 return CB_ERR_ARG;
 376
 377         err = thread_join(&context->handle);
 378         if (err != CB_SUCCESS) {
 379                 ERROR("%s(name='%s') Preload thread failed: %u\n", __func__, name, err);
 380
 381                 goto out;
 382         }
 383
 384         if (rdev_chain_mem(rdev, context->buffer, region_device_sz(&context->rdev)) != 0) {
 385                 ERROR("%s(name='%s') chaining failed\n", __func__, name);
 386
 387                 err = CB_ERR;
 388                 goto out;
 389         }
 390
 391         err = CB_SUCCESS;
 392
 393         DEBUG("%s(name='%s') preload successful\n", __func__, name);
 394
 395 out:
 396         free_cbfs_preload_context(context);
 397
 398         return err;
 399 }
 400
 401 static void *do_alloc(union cbfs_mdata *mdata, struct region_device *rdev,
 402                       cbfs_allocator_t allocator, void *arg, size_t *size_out,
 403                       bool skip_verification)
 404 {
 405         size_t size = region_device_sz(rdev);
 406         void *loc = NULL;
 407
 408         uint32_t compression = CBFS_COMPRESS_NONE;
 409         const struct cbfs_file_attr_compression *cattr = cbfs_find_attr(mdata,
 410                                 CBFS_FILE_ATTR_TAG_COMPRESSION, sizeof(*cattr));
 411         if (cattr) {
 412                 compression = be32toh(cattr->compression);
 413                 size = be32toh(cattr->decompressed_size);
 414         }
 415
 416         if (size_out)
 417                 *size_out = size;
 418
 419         /* allocator == NULL means do a cbfs_map() */
 420         if (allocator) {
 421                 loc = allocator(arg, size, mdata);
 422         } else if (compression == CBFS_COMPRESS_NONE) {
 423                 void *mapping = rdev_mmap_full(rdev);
 424                 if (!mapping)
 425                         return NULL;
 426                 if (cbfs_file_hash_mismatch(mapping, size, mdata, skip_verification)) {
 427                         rdev_munmap(rdev, mapping);
 428                         return NULL;
 429                 }
 430                 return mapping;
 431         } else if (!cbfs_cache.size) {
 432                 /* In order to use the cbfs_cache you need to add a CBFS_CACHE to your
 433                  * memlayout. For stages that don't have .data sections (x86 pre-RAM),
 434                  * it is not possible to add a CBFS_CACHE. */
 435                 ERROR("Cannot map compressed file %s without cbfs_cache\n", mdata->h.filename);
 436                 return NULL;
 437         } else {
 438                 loc = mem_pool_alloc(&cbfs_cache, size);
 439         }
 440
 441         if (!loc) {
 442                 ERROR("'%s' allocation failure\n", mdata->h.filename);
 443                 return NULL;
 444         }
 445
 446         size = cbfs_load_and_decompress(rdev, loc, size, compression, mdata, skip_verification);
 447         if (!size)
 448                 return NULL;
 449
 450         return loc;
 451 }
 452
 453 void *_cbfs_alloc(const char *name, cbfs_allocator_t allocator, void *arg,
 454                   size_t *size_out, bool force_ro, enum cbfs_type *type)
 455 {
 456         struct region_device rdev;
 457         bool preload_successful = false;
 458         union cbfs_mdata mdata;
 459
 460         DEBUG("%s(name='%s', alloc=%p(%p), force_ro=%s, type=%d)\n", __func__, name, allocator,
 461               arg, force_ro ? "true" : "false", type ? *type : -1);
 462
 463         if (_cbfs_boot_lookup(name, force_ro, &mdata, &rdev))
 464                 return NULL;
 465
 466         if (type) {
 467                 const enum cbfs_type real_type = be32toh(mdata.h.type);
 468                 if (*type == CBFS_TYPE_QUERY)
 469                         *type = real_type;
 470                 else if (*type != real_type) {
 471                         ERROR("'%s' type mismatch (is %u, expected %u)\n",
 472                               mdata.h.filename, real_type, *type);
 473                         return NULL;
 474                 }
 475         }
 476
 477         /* Update the rdev with the preload content */
 478         if (!force_ro && get_preload_rdev(&rdev, name) == CB_SUCCESS)
 479                 preload_successful = true;
 480
 481         void *ret = do_alloc(&mdata, &rdev, allocator, arg, size_out, false);
 482
 483         /* When using cbfs_preload we need to free the preload buffer after populating the
 484          * destination buffer. We know we must have a mem_rdev here, so extra mmap is fine. */
 485         if (preload_successful)
 486                 cbfs_unmap(rdev_mmap_full(&rdev));
 487
 488         return ret;
 489 }
 490
 491 void *_cbfs_unverified_area_alloc(const char *area, const char *name,
 492                                   cbfs_allocator_t allocator, void *arg, size_t *size_out)
 493 {
 494         struct region_device area_rdev, file_rdev;
 495         union cbfs_mdata mdata;
 496         size_t data_offset;
 497
 498         DEBUG("%s(area='%s', name='%s', alloc=%p(%p))\n", __func__, area, name, allocator, arg);
 499
 500         if (fmap_locate_area_as_rdev(area, &area_rdev))
 501                 return NULL;
 502
 503         if (cbfs_lookup(&area_rdev, name, &mdata, &data_offset, NULL)) {
 504                 ERROR("'%s' not found in '%s'\n", name, area);
 505                 return NULL;
 506         }
 507
 508         if (rdev_chain(&file_rdev, &area_rdev, data_offset, be32toh(mdata.h.len)))
 509                 return NULL;
 510
 511         return do_alloc(&mdata, &file_rdev, allocator, arg, size_out, true);
 512 }
 513
 514 void *_cbfs_default_allocator(void *arg, size_t size, const union cbfs_mdata *unused)
 515 {
 516         struct _cbfs_default_allocator_arg *darg = arg;
 517         if (size > darg->buf_size)
 518                 return NULL;
 519         return darg->buf;
 520 }
 521
 522 void *_cbfs_cbmem_allocator(void *arg, size_t size, const union cbfs_mdata *unused)
 523 {
 524         return cbmem_add((uintptr_t)arg, size);
 525 }
 526
 527 enum cb_err cbfs_prog_stage_load(struct prog *pstage)
 528 {
 529         union cbfs_mdata mdata;
 530         struct region_device rdev;
 531         enum cb_err err;
 532
 533         prog_locate_hook(pstage);
 534
 535         if ((err = _cbfs_boot_lookup(prog_name(pstage), false, &mdata, &rdev)))
 536                 return err;
 537
 538         assert(be32toh(mdata.h.type) == CBFS_TYPE_STAGE);
 539         pstage->cbfs_type = CBFS_TYPE_STAGE;
 540
 541         enum cbfs_compression compression = CBFS_COMPRESS_NONE;
 542         const struct cbfs_file_attr_compression *cattr = cbfs_find_attr(&mdata,
 543                                 CBFS_FILE_ATTR_TAG_COMPRESSION, sizeof(*cattr));
 544         if (cattr)
 545                 compression = be32toh(cattr->compression);
 546
 547         const struct cbfs_file_attr_stageheader *sattr = cbfs_find_attr(&mdata,
 548                                 CBFS_FILE_ATTR_TAG_STAGEHEADER, sizeof(*sattr));
 549         if (!sattr)
 550                 return CB_ERR;
 551         prog_set_area(pstage, (void *)(uintptr_t)be64toh(sattr->loadaddr),
 552                       be32toh(sattr->memlen));
 553         prog_set_entry(pstage, prog_start(pstage) +
 554                                be32toh(sattr->entry_offset), NULL);
 555
 556         /* Hacky way to not load programs over read only media. The stages
 557          * that would hit this path initialize themselves. */
 558         if ((ENV_BOOTBLOCK || ENV_SEPARATE_VERSTAGE) &&
 559             !CONFIG(NO_XIP_EARLY_STAGES) && CONFIG(BOOT_DEVICE_MEMORY_MAPPED)) {
 560                 void *mapping = rdev_mmap_full(&rdev);
 561                 rdev_munmap(&rdev, mapping);
 562                 if (cbfs_file_hash_mismatch(mapping, region_device_sz(&rdev), &mdata, false))
 563                         return CB_CBFS_HASH_MISMATCH;
 564                 if (mapping == prog_start(pstage))
 565                         return CB_SUCCESS;
 566         }
 567
 568         /* LZ4 stages can be decompressed in-place to save mapping scratch space. Load the
 569            compressed data to the end of the buffer and point &rdev to that memory location. */
 570         if (cbfs_lz4_enabled() && compression == CBFS_COMPRESS_LZ4) {
 571                 size_t in_size = region_device_sz(&rdev);
 572                 void *compr_start = prog_start(pstage) + prog_size(pstage) - in_size;
 573                 if (rdev_readat(&rdev, compr_start, 0, in_size) != in_size)
 574                         return CB_ERR;
 575                 rdev_chain_mem(&rdev, compr_start, in_size);
 576         }
 577
 578         size_t fsize = cbfs_load_and_decompress(&rdev, prog_start(pstage), prog_size(pstage),
 579                                                 compression, &mdata, false);
 580         if (!fsize)
 581                 return CB_ERR;
 582
 583         /* Clear area not covered by file. */
 584         memset(prog_start(pstage) + fsize, 0, prog_size(pstage) - fsize);
 585
 586         prog_segment_loaded((uintptr_t)prog_start(pstage), prog_size(pstage),
 587                             SEG_FINAL);
 588
 589         return CB_SUCCESS;
 590 }
 591
 592 void cbfs_boot_device_find_mcache(struct cbfs_boot_device *cbd, uint32_t id)
 593 {
 594         if (CONFIG(NO_CBFS_MCACHE) || ENV_SMM)
 595                 return;
 596
 597         if (cbd->mcache_size)
 598                 return;
 599
 600         const struct cbmem_entry *entry;
 601         if (cbmem_possibly_online() &&
 602             (entry = cbmem_entry_find(id))) {
 603                 cbd->mcache = cbmem_entry_start(entry);
 604                 cbd->mcache_size = cbmem_entry_size(entry);
 605         } else if (ENV_ROMSTAGE_OR_BEFORE) {
 606                 u8 *boundary = _ecbfs_mcache - REGION_SIZE(cbfs_mcache) *
 607                         CONFIG_CBFS_MCACHE_RW_PERCENTAGE / 100;
 608                 boundary = (u8 *)ALIGN_DOWN((uintptr_t)boundary, CBFS_MCACHE_ALIGNMENT);
 609                 if (id == CBMEM_ID_CBFS_RO_MCACHE) {
 610                         cbd->mcache = _cbfs_mcache;
 611                         cbd->mcache_size = boundary - _cbfs_mcache;
 612                 } else if (id == CBMEM_ID_CBFS_RW_MCACHE) {
 613                         cbd->mcache = boundary;
 614                         cbd->mcache_size = _ecbfs_mcache - boundary;
 615                 }
 616         }
 617 }
 618
 619 enum cb_err cbfs_init_boot_device(const struct cbfs_boot_device *cbd,
 620                                   struct vb2_hash *mdata_hash)
 621 {
 622         /* If we have an mcache, mcache_build() will also check mdata hash. */
 623         if (!CONFIG(NO_CBFS_MCACHE) && !ENV_SMM && cbd->mcache_size > 0)
 624                 return cbfs_mcache_build(&cbd->rdev, cbd->mcache, cbd->mcache_size, mdata_hash);
 625
 626         /* No mcache and no verification means we have nothing special to do. */
 627         if (!CONFIG(CBFS_VERIFICATION) || !mdata_hash)
 628                 return CB_SUCCESS;
 629
 630         /* Verification only: use cbfs_walk() without a walker() function to just run through
 631            the CBFS once, will return NOT_FOUND by default. */
 632         enum cb_err err = cbfs_walk(&cbd->rdev, NULL, NULL, mdata_hash, 0);
 633         if (err == CB_CBFS_NOT_FOUND)
 634                 err = CB_SUCCESS;
 635         return err;
 636 }
 637
 638 const struct cbfs_boot_device *cbfs_get_boot_device(bool force_ro)
 639 {
 640         static struct cbfs_boot_device ro;
 641
 642         /* Ensure we always init RO mcache, even if the first file is from the RW CBFS.
 643            Otherwise it may not be available when needed in later stages. */
 644         if (ENV_INITIAL_STAGE && !force_ro && !region_device_sz(&ro.rdev))
 645                 cbfs_get_boot_device(true);
 646
 647         if (!force_ro) {
 648                 const struct cbfs_boot_device *rw = vboot_get_cbfs_boot_device();
 649                 /* This will return NULL if vboot isn't enabled, didn't run yet or decided to
 650                    boot into recovery mode. */
 651                 if (rw)
 652                         return rw;
 653         }
 654
 655         /* In rare cases post-RAM stages may run this before cbmem_initialize(), so we can't
 656            lock in the result of find_mcache() on the first try and should keep trying every
 657            time until an mcache is found. */
 658         cbfs_boot_device_find_mcache(&ro, CBMEM_ID_CBFS_RO_MCACHE);
 659
 660         if (region_device_sz(&ro.rdev))
 661                 return &ro;
 662
 663         if (fmap_locate_area_as_rdev("COREBOOT", &ro.rdev))
 664                 die("Cannot locate primary CBFS");
 665
 666         if (ENV_INITIAL_STAGE) {
 667                 enum cb_err err = cbfs_init_boot_device(&ro, metadata_hash_get());
 668                 if (err == CB_CBFS_HASH_MISMATCH)
 669                         die("RO CBFS metadata hash verification failure");
 670                 else if (CONFIG(TOCTOU_SAFETY) && err == CB_CBFS_CACHE_FULL)
 671                         die("RO mcache overflow breaks TOCTOU safety!\n");
 672                 else if (err && err != CB_CBFS_CACHE_FULL)
 673                         die("RO CBFS initialization error: %d", err);
 674         }
 675
 676         return &ro;
 677 }
 678
 679 #if !CONFIG(NO_CBFS_MCACHE)
 680 static void mcache_to_cbmem(const struct cbfs_boot_device *cbd, u32 cbmem_id)
 681 {
 682         if (!cbd)
 683                 return;
 684
 685         size_t real_size = cbfs_mcache_real_size(cbd->mcache, cbd->mcache_size);
 686         void *cbmem_mcache = cbmem_add(cbmem_id, real_size);
 687         if (!cbmem_mcache) {
 688                 printk(BIOS_ERR, "Cannot allocate CBMEM mcache %#x (%#zx bytes)!\n",
 689                        cbmem_id, real_size);
 690                 return;
 691         }
 692         memcpy(cbmem_mcache, cbd->mcache, real_size);
 693 }
 694
 695 static void cbfs_mcache_migrate(int unused)
 696 {
 697         mcache_to_cbmem(vboot_get_cbfs_boot_device(), CBMEM_ID_CBFS_RW_MCACHE);
 698         mcache_to_cbmem(cbfs_get_boot_device(true), CBMEM_ID_CBFS_RO_MCACHE);
 699 }
 700 CBMEM_CREATION_HOOK(cbfs_mcache_migrate);
 701 #endif