src/commonlib/fsp1_1_relocate.c

   1 /*
   2  * This file is part of the coreboot project.
   3  *
   4  * Copyright 2015 Google Inc
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 of the License.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <console/console.h>
  17 #include <commonlib/endian.h>
  18 #include <commonlib/fsp1_1.h>
  19 #include <commonlib/helpers.h>
  20 #include <stdlib.h>
  21 #include <stdint.h>
  22 #include <string.h>
  23
  24 #define FSP_DBG_LVL BIOS_NEVER
  25
  26 /*
  27  * UEFI defines everything as little endian. However, this piece of code
  28  * can be integrated in a userland tool. That tool could be on a big endian
  29  * machine so one needs to access the fields within UEFI structures using
  30  * endian-aware accesses.
  31  */
  32
  33 /* Return 0 if equal. Non-zero if not equal. */
  34 static int guid_compare(const EFI_GUID *le_guid, const EFI_GUID *native_guid)
  35 {
  36         if (read_le32(&le_guid->Data1) != native_guid->Data1)
  37                 return 1;
  38         if (read_le16(&le_guid->Data2) != native_guid->Data2)
  39                 return 1;
  40         if (read_le16(&le_guid->Data3) != native_guid->Data3)
  41                 return 1;
  42         return memcmp(le_guid->Data4, native_guid->Data4,
  43                         ARRAY_SIZE(le_guid->Data4));
  44 }
  45
  46 /* Provide this for symmetry when accessing UEFI fields. */
  47 static inline uint8_t le8toh(uint8_t byte)
  48 {
  49         return byte;
  50 }
  51
  52 static const EFI_GUID ffs2_guid = EFI_FIRMWARE_FILE_SYSTEM2_GUID;
  53 static const EFI_GUID fih_guid = FSP_INFO_HEADER_GUID;
  54
  55 struct fsp_patch_table {
  56         uint32_t signature;
  57         uint16_t header_length;
  58         uint8_t header_revision;
  59         uint8_t reserved;
  60         uint32_t patch_entry_num;
  61         uint32_t patch_entries[0];
  62 } __attribute__((packed));
  63
  64 #define FSPP_SIG 0x50505346
  65
  66 static void *relative_offset(void *base, ssize_t offset)
  67 {
  68         uintptr_t loc;
  69
  70         loc = (uintptr_t)base;
  71         loc += offset;
  72
  73         return (void *)loc;
  74 }
  75
  76 static uint32_t *fspp_reloc(void *fsp, size_t fsp_size, uint32_t e)
  77 {
  78         size_t offset;
  79
  80         /* Offsets live in bits 23:0. */
  81         offset = e & 0xffffff;
  82
  83         /* If bit 31 is set then the offset is considered a negative value
  84          * relative to the end of the image using 16MiB as the offset's
  85          * reference. */
  86         if (e & (1 << 31))
  87                 offset = fsp_size - (16 * MiB - offset);
  88
  89         /* Determine if offset falls within fsp_size for a 32 bit relocation. */
  90         if (offset > fsp_size - sizeof(uint32_t))
  91                 return NULL;
  92
  93         return relative_offset(fsp, offset);
  94 }
  95
  96 static int reloc_type(uint16_t reloc_entry)
  97 {
  98         /* Reloc type in upper 4 bits */
  99         return reloc_entry >> 12;
 100 }
 101
 102 static size_t reloc_offset(uint16_t reloc_entry)
 103 {
 104         /* Offsets are in low 12 bits. */
 105         return reloc_entry & ((1 << 12) - 1);
 106 }
 107
 108 static int te_relocate(uintptr_t new_addr, void *te)
 109 {
 110         EFI_TE_IMAGE_HEADER *teih;
 111         EFI_IMAGE_DATA_DIRECTORY *relocd;
 112         EFI_IMAGE_BASE_RELOCATION *relocb;
 113         uintptr_t image_base;
 114         size_t fixup_offset;
 115         size_t num_relocs;
 116         uint16_t *reloc;
 117         size_t relocd_offset;
 118         uint8_t *te_base;
 119         uint32_t adj;
 120
 121         teih = te;
 122
 123         if (read_le16(&teih->Signature) != EFI_TE_IMAGE_HEADER_SIGNATURE) {
 124                 printk(BIOS_ERR, "TE Signature mismatch: %x vs %x\n",
 125                         read_le16(&teih->Signature),
 126                         EFI_TE_IMAGE_HEADER_SIGNATURE);
 127                 return -1;
 128         }
 129
 130         /*
 131          * A TE image is created by converting a PE file. Because of this
 132          * the offsets within the headers are off. In order to calculate
 133          * the correct releative offets one needs to subtract fixup_offset
 134          * from the encoded offets.  Similarly, the linked address of the
 135          * program is found by adding the fixup_offset to the ImageBase.
 136          */
 137         fixup_offset = read_le16(&teih->StrippedSize);
 138         fixup_offset -= sizeof(EFI_TE_IMAGE_HEADER);
 139         /* Keep track of a base that is correctly adjusted so that offsets
 140          * can be used directly. */
 141         te_base = te;
 142         te_base -= fixup_offset;
 143
 144         image_base = read_le64(&teih->ImageBase);
 145         adj = new_addr - (image_base + fixup_offset);
 146
 147         printk(FSP_DBG_LVL, "TE Image %p -> %p adjust value: %x\n",
 148                 (void *)image_base, (void *)new_addr, adj);
 149
 150         /* Adjust ImageBase for consistency. */
 151         write_le64(&teih->ImageBase, (uint32_t)(image_base + adj));
 152
 153         relocd = &teih->DataDirectory[EFI_TE_IMAGE_DIRECTORY_ENTRY_BASERELOC];
 154
 155         relocd_offset = 0;
 156         /* Though the field name is VirtualAddress it's actually relative to
 157          * the beginning of the image which is linked at ImageBase. */
 158         relocb = relative_offset(te,
 159                         read_le32(&relocd->VirtualAddress) - fixup_offset);
 160         while (relocd_offset < read_le32(&relocd->Size)) {
 161                 size_t rva_offset = read_le32(&relocb->VirtualAddress);
 162
 163                 printk(FSP_DBG_LVL, "Relocs for RVA offset %zx\n", rva_offset);
 164                 num_relocs = read_le32(&relocb->SizeOfBlock) - sizeof(*relocb);
 165                 num_relocs /= sizeof(uint16_t);
 166                 reloc = relative_offset(relocb, sizeof(*relocb));
 167
 168                 printk(FSP_DBG_LVL, "Num relocs in block: %zx\n", num_relocs);
 169
 170                 while (num_relocs > 0) {
 171                         uint16_t reloc_val = read_le16(reloc);
 172                         int type = reloc_type(reloc_val);
 173                         size_t offset = reloc_offset(reloc_val);
 174
 175                         printk(FSP_DBG_LVL, "reloc type %x offset %zx\n",
 176                                 type, offset);
 177
 178                         if (type == EFI_IMAGE_REL_BASED_HIGHLOW) {
 179                                 uint32_t *reloc_addr;
 180                                 uint32_t val;
 181
 182                                 offset += rva_offset;
 183                                 reloc_addr = (void *)&te_base[offset];
 184                                 val = read_le32(reloc_addr);
 185
 186                                 printk(FSP_DBG_LVL, "Adjusting %p %x -> %x\n",
 187                                         reloc_addr, val, val + adj);
 188                                 write_le32(reloc_addr, val + adj);
 189                         } else if (type != EFI_IMAGE_REL_BASED_ABSOLUTE) {
 190                                 printk(BIOS_ERR, "Unknown reloc type: %x\n",
 191                                         type);
 192                                 return -1;
 193                         }
 194                         num_relocs--;
 195                         reloc++;
 196                 }
 197
 198                 /* Track consumption of relocation directory contents. */
 199                 relocd_offset += read_le32(&relocb->SizeOfBlock);
 200                 /* Get next relocation block to process. */
 201                 relocb = relative_offset(relocb,
 202                                         read_le32(&relocb->SizeOfBlock));
 203         }
 204
 205         return 0;
 206 }
 207
 208 static size_t csh_size(const EFI_COMMON_SECTION_HEADER *csh)
 209 {
 210         size_t size;
 211
 212         /* Unpack the array into a type that can be used. */
 213         size = 0;
 214         size |= read_le8(&csh->Size[0]) << 0;
 215         size |= read_le8(&csh->Size[1]) << 8;
 216         size |= read_le8(&csh->Size[2]) << 16;
 217
 218         return size;
 219 }
 220
 221 static size_t section_data_offset(const EFI_COMMON_SECTION_HEADER *csh)
 222 {
 223         if (csh_size(csh) == 0x00ffffff)
 224                 return sizeof(EFI_COMMON_SECTION_HEADER2);
 225         else
 226                 return sizeof(EFI_COMMON_SECTION_HEADER);
 227 }
 228
 229 static size_t section_data_size(const EFI_COMMON_SECTION_HEADER *csh)
 230 {
 231         size_t section_size;
 232
 233         if (csh_size(csh) == 0x00ffffff)
 234                 section_size = read_le32(&SECTION2_SIZE(csh));
 235         else
 236                 section_size = csh_size(csh);
 237
 238         return section_size - section_data_offset(csh);
 239 }
 240
 241 static size_t file_section_offset(const EFI_FFS_FILE_HEADER *ffsfh)
 242 {
 243         if (IS_FFS_FILE2(ffsfh))
 244                 return sizeof(EFI_FFS_FILE_HEADER2);
 245         else
 246                 return sizeof(EFI_FFS_FILE_HEADER);
 247 }
 248
 249 static size_t ffs_file_size(const EFI_FFS_FILE_HEADER *ffsfh)
 250 {
 251         size_t size;
 252
 253         if (IS_FFS_FILE2(ffsfh))
 254                 size = read_le32(&FFS_FILE2_SIZE(ffsfh));
 255         else {
 256                 size = read_le8(&ffsfh->Size[0]) << 0;
 257                 size |= read_le8(&ffsfh->Size[1]) << 8;
 258                 size |= read_le8(&ffsfh->Size[2]) << 16;
 259         }
 260         return size;
 261 }
 262
 263 static int relocate_patch_table(void *fsp, size_t size, size_t offset,
 264                                 ssize_t adjustment)
 265 {
 266         struct fsp_patch_table *table;
 267         size_t num;
 268         size_t num_entries;
 269
 270         table = relative_offset(fsp, offset);
 271
 272         if ((offset + sizeof(*table) > size) ||
 273             (read_le16(&table->header_length) + offset) > size) {
 274                 printk(BIOS_ERR, "FSPP not entirely contained in region.\n");
 275                 return -1;
 276         }
 277
 278         num_entries = read_le32(&table->patch_entry_num);
 279         printk(FSP_DBG_LVL, "FSPP relocs: %zx\n", num_entries);
 280
 281         for (num = 0; num < num_entries; num++) {
 282                 uint32_t *reloc;
 283                 uint32_t reloc_val;
 284
 285                 reloc = fspp_reloc(fsp, size,
 286                                 read_le32(&table->patch_entries[num]));
 287
 288                 if (reloc == NULL) {
 289                         printk(BIOS_ERR, "Ignoring FSPP entry: %x\n",
 290                                 read_le32(&table->patch_entries[num]));
 291                         continue;
 292                 }
 293
 294                 reloc_val = read_le32(reloc);
 295                 printk(FSP_DBG_LVL, "Adjusting %p %x -> %x\n",
 296                         reloc, reloc_val,
 297                         (unsigned int)(reloc_val + adjustment));
 298
 299                 write_le32(reloc, reloc_val + adjustment);
 300         }
 301
 302         return 0;
 303 }
 304
 305 static ssize_t relocate_remaining_items(void *fsp, size_t size,
 306                                         uintptr_t new_addr, size_t fih_offset)
 307 {
 308         EFI_FFS_FILE_HEADER *ffsfh;
 309         EFI_COMMON_SECTION_HEADER *csh;
 310         FSP_INFO_HEADER *fih;
 311         ssize_t adjustment;
 312         size_t offset;
 313
 314         printk(FSP_DBG_LVL, "FSP_INFO_HEADER offset is %zx\n", fih_offset);
 315
 316         if (fih_offset == 0) {
 317                 printk(BIOS_ERR, "FSP_INFO_HEADER offset is 0.\n");
 318                 return -1;
 319         }
 320
 321         /* FSP_INFO_HEADER at first file in FV within first RAW section. */
 322         ffsfh = relative_offset(fsp, fih_offset);
 323         fih_offset += file_section_offset(ffsfh);
 324         csh = relative_offset(fsp, fih_offset);
 325         fih_offset += section_data_offset(csh);
 326         fih = relative_offset(fsp, fih_offset);
 327
 328         if (guid_compare(&ffsfh->Name, &fih_guid)) {
 329                 printk(BIOS_ERR, "Bad FIH GUID.\n");
 330                 return -1;
 331         }
 332
 333         if (read_le8(&csh->Type) != EFI_SECTION_RAW) {
 334                 printk(BIOS_ERR, "FIH file should have raw section: %x\n",
 335                         read_le8(&csh->Type));
 336                 return -1;
 337         }
 338
 339         if (read_le32(&fih->Signature) != FSP_SIG) {
 340                 printk(BIOS_ERR, "Unexpected FIH signature: %08x\n",
 341                         read_le32(&fih->Signature));
 342                 return -1;
 343         }
 344
 345         adjustment = (intptr_t)new_addr - read_le32(&fih->ImageBase);
 346
 347         /* Update ImageBase to reflect FSP's new home. */
 348         write_le32(&fih->ImageBase, adjustment + read_le32(&fih->ImageBase));
 349
 350         /* Need to find patch table and adjust each entry. The tables
 351          * following FSP_INFO_HEADER have a 32-bit signature and header
 352          * length. The patch table is denoted as having a 'FSPP' signature;
 353          * the table format doesn't follow the other tables. */
 354         offset = fih_offset + read_le32(&fih->HeaderLength);
 355         while (offset + 2 * sizeof(uint32_t) <= size) {
 356                 uint32_t *table_headers;
 357
 358                 table_headers = relative_offset(fsp, offset);
 359
 360                 printk(FSP_DBG_LVL, "Checking offset %zx for 'FSPP'\n",
 361                         offset);
 362
 363                 if (read_le32(&table_headers[0]) != FSPP_SIG) {
 364                         offset += read_le32(&table_headers[1]);
 365                         continue;
 366                 }
 367
 368                 if (relocate_patch_table(fsp, size, offset, adjustment)) {
 369                         printk(BIOS_ERR, "FSPP relocation failed.\n");
 370                         return -1;
 371                 }
 372
 373                 return fih_offset;
 374         }
 375
 376         printk(BIOS_ERR, "Could not find the FSP patch table.\n");
 377         return -1;
 378 }
 379
 380 static ssize_t relocate_fvh(uintptr_t new_addr, void *fsp, size_t fsp_size,
 381                                 size_t fvh_offset, size_t *fih_offset)
 382 {
 383         EFI_FIRMWARE_VOLUME_HEADER *fvh;
 384         EFI_FFS_FILE_HEADER *ffsfh;
 385         EFI_COMMON_SECTION_HEADER *csh;
 386         size_t offset;
 387         size_t file_offset;
 388         size_t size;
 389         size_t fv_length;
 390
 391         offset = fvh_offset;
 392         fvh = relative_offset(fsp, offset);
 393
 394         if (read_le32(&fvh->Signature) != EFI_FVH_SIGNATURE)
 395                 return -1;
 396
 397         fv_length = read_le64(&fvh->FvLength);
 398
 399         printk(FSP_DBG_LVL, "FVH length: %zx Offset: %zx Mapping length: %zx\n",
 400                 fv_length, offset, fsp_size);
 401
 402         if (fv_length + offset > fsp_size)
 403                 return -1;
 404
 405         /* Parse only this FV. However, the algorithm uses offsets into the
 406          * entire FSP region so make size include the starting offset. */
 407         size = fv_length + offset;
 408
 409         if (guid_compare(&fvh->FileSystemGuid, &ffs2_guid)) {
 410                 printk(BIOS_ERR, "FVH not an FFS2 type.\n");
 411                 return -1;
 412         }
 413
 414         if (read_le16(&fvh->ExtHeaderOffset) != 0) {
 415                 EFI_FIRMWARE_VOLUME_EXT_HEADER *fveh;
 416
 417                 offset += read_le16(&fvh->ExtHeaderOffset);
 418                 fveh = relative_offset(fsp, offset);
 419                 printk(FSP_DBG_LVL, "Extended Header Offset: %zx Size: %zx\n",
 420                         (size_t)read_le16(&fvh->ExtHeaderOffset),
 421                         (size_t)read_le32(&fveh->ExtHeaderSize));
 422                 offset += read_le32(&fveh->ExtHeaderSize);
 423                 /* FFS files are 8 byte aligned after extended header. */
 424                 offset = ALIGN_UP(offset, 8);
 425         } else {
 426                 offset += read_le16(&fvh->HeaderLength);
 427         }
 428
 429         file_offset = offset;
 430         while (file_offset + sizeof(*ffsfh) < size) {
 431                 offset = file_offset;
 432                 printk(FSP_DBG_LVL, "file offset: %zx\n", file_offset);
 433
 434                 /* First file and section should be FSP info header. */
 435                 if (fih_offset != NULL && *fih_offset == 0)
 436                         *fih_offset = file_offset;
 437
 438                 ffsfh = relative_offset(fsp, file_offset);
 439
 440                 printk(FSP_DBG_LVL, "file type = %x\n", read_le8(&ffsfh->Type));
 441                 printk(FSP_DBG_LVL, "file attribs = %x\n",
 442                         read_le8(&ffsfh->Attributes));
 443
 444                 /* Exit FV relocation when empty space found */
 445                 if (read_le8(&ffsfh->Type) == EFI_FV_FILETYPE_FFS_MAX)
 446                         break;
 447
 448                 /* Next file on 8 byte alignment. */
 449                 file_offset += ffs_file_size(ffsfh);
 450                 file_offset = ALIGN_UP(file_offset, 8);
 451
 452                 /* Padding files have no section information. */
 453                 if (read_le8(&ffsfh->Type) == EFI_FV_FILETYPE_FFS_PAD)
 454                         continue;
 455
 456                 offset += file_section_offset(ffsfh);
 457
 458                 while (offset + sizeof(*csh) < file_offset) {
 459                         size_t data_size;
 460                         size_t data_offset;
 461
 462                         csh = relative_offset(fsp, offset);
 463
 464                         printk(FSP_DBG_LVL, "section offset: %zx\n", offset);
 465                         printk(FSP_DBG_LVL, "section type: %x\n",
 466                                 read_le8(&csh->Type));
 467
 468                         data_size = section_data_size(csh);
 469                         data_offset = section_data_offset(csh);
 470
 471                         if (data_size + data_offset + offset > file_offset) {
 472                                 printk(BIOS_ERR, "Section exceeds FV size.\n");
 473                                 return -1;
 474                         }
 475
 476                         /*
 477                          * The entire FSP 1.1 image can be thought of as one
 478                          * program with a single link address even though there
 479                          * are multiple TEs linked separately. The reason is
 480                          * that each TE is linked for XIP. So in order to
 481                          * relocate the TE properly we need to form the
 482                          * relocated address based on the TE offset within
 483                          * FSP proper.
 484                          */
 485                         if (read_le8(&csh->Type) == EFI_SECTION_TE) {
 486                                 void *te;
 487                                 size_t te_offset = offset + data_offset;
 488                                 uintptr_t te_addr = new_addr + te_offset;
 489
 490                                 printk(FSP_DBG_LVL, "TE image at offset %zx\n",
 491                                         te_offset);
 492                                 te = relative_offset(fsp, te_offset);
 493                                 te_relocate(te_addr, te);
 494                         }
 495
 496                         offset += data_size + data_offset;
 497                         /* Sections are aligned to 4 bytes. */
 498                         offset = ALIGN_UP(offset, 4);
 499                 }
 500         }
 501
 502         /* Return amount of buffer parsed: FV size. */
 503         return fv_length;
 504 }
 505
 506 ssize_t fsp1_1_relocate(uintptr_t new_addr, void *fsp, size_t size)
 507 {
 508         size_t offset;
 509         size_t fih_offset;
 510
 511         offset = 0;
 512         fih_offset = 0;
 513         while (offset < size) {
 514                 ssize_t nparsed;
 515
 516                 /* Relocate each FV within the FSP region. The FSP_INFO_HEADER
 517                  * should only be located in the first FV. */
 518                 if (offset == 0)
 519                         nparsed = relocate_fvh(new_addr, fsp, size, offset,
 520                                                 &fih_offset);
 521                 else
 522                         nparsed = relocate_fvh(new_addr, fsp, size, offset,
 523                                                 NULL);
 524
 525                 /* FV should be larger than 0 or failed to parse. */
 526                 if (nparsed <= 0) {
 527                         printk(BIOS_ERR, "FV @ offset %zx relocation failed\n",
 528                                 offset);
 529                         return -1;
 530                 }
 531
 532                 offset += nparsed;
 533         }
 534
 535         return relocate_remaining_items(fsp, size, new_addr, fih_offset);
 536 }