1 /** @file 2 3 This is a simple fault tolerant write driver that is intended to use in the SMM environment. 4 5 This boot service protocol only provides fault tolerant write capability for 6 block devices. The protocol has internal non-volatile intermediate storage 7 of the data and private information. It should be able to recover 8 automatically from a critical fault, such as power failure. 9 10 The implementation uses an FTW (Fault Tolerant Write) Work Space. 11 This work space is a memory copy of the work space on the Working Block, 12 the size of the work space is the FTW_WORK_SPACE_SIZE bytes. 13 14 The work space stores each write record as EFI_FTW_RECORD structure. 15 The spare block stores the write buffer before write to the target block. 16 17 The write record has three states to specify the different phase of write operation. 18 1) WRITE_ALLOCATED is that the record is allocated in write space. 19 The information of write operation is stored in write record structure. 20 2) SPARE_COMPLETED is that the data from write buffer is writed into the spare block as the backup. 21 3) WRITE_COMPLETED is that the data is copied from the spare block to the target block. 22 23 This driver operates the data as the whole size of spare block. 24 It first read the SpareAreaLength data from the target block into the spare memory buffer. 25 Then copy the write buffer data into the spare memory buffer. 26 Then write the spare memory buffer into the spare block. 27 Final copy the data from the spare block to the target block. 28 29 To make this drive work well, the following conditions must be satisfied: 30 1. The write NumBytes data must be fit within Spare area. 31 Offset + NumBytes <= SpareAreaLength 32 2. The whole flash range has the same block size. 33 3. Working block is an area which contains working space in its last block and has the same size as spare block. 34 4. Working Block area must be in the single one Firmware Volume Block range which FVB protocol is produced on. 35 5. Spare area must be in the single one Firmware Volume Block range which FVB protocol is produced on. 36 6. Any write data area (SpareAreaLength Area) which the data will be written into must be 37 in the single one Firmware Volume Block range which FVB protocol is produced on. 38 7. If write data area (such as Variable range) is enlarged, the spare area range must be enlarged. 39 The spare area must be enough large to store the write data before write them into the target range. 40 If one of them is not satisfied, FtwWrite may fail. 41 Usually, Spare area only takes one block. That's SpareAreaLength = BlockSize, NumberOfSpareBlock = 1. 42 43 Caution: This module requires additional review when modified. 44 This driver need to make sure the CommBuffer is not in the SMRAM range. 45 46 Copyright (c) 2010 - 2015, Intel Corporation. All rights reserved.<BR> 47 This program and the accompanying materials 48 are licensed and made available under the terms and conditions of the BSD License 49 which accompanies this distribution. The full text of the license may be found at 50 http://opensource.org/licenses/bsd-license.php 51 52 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 53 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 54 55 **/ 56 57 #include <PiSmm.h> 58 #include <Library/SmmServicesTableLib.h> 59 #include <Library/SmmMemLib.h> 60 #include <Protocol/SmmSwapAddressRange.h> 61 #include "FaultTolerantWrite.h" 62 #include "FaultTolerantWriteSmmCommon.h" 63 #include <Protocol/SmmEndOfDxe.h> 64 65 EFI_EVENT mFvbRegistration = NULL; 66 EFI_FTW_DEVICE *mFtwDevice = NULL; 67 68 /// 69 /// The flag to indicate whether the platform has left the DXE phase of execution. 70 /// 71 BOOLEAN mEndOfDxe = FALSE; 72 73 /** 74 Retrive the SMM FVB protocol interface by HANDLE. 75 76 @param[in] FvBlockHandle The handle of SMM FVB protocol that provides services for 77 reading, writing, and erasing the target block. 78 @param[out] FvBlock The interface of SMM FVB protocol 79 80 @retval EFI_SUCCESS The interface information for the specified protocol was returned. 81 @retval EFI_UNSUPPORTED The device does not support the SMM FVB protocol. 82 @retval EFI_INVALID_PARAMETER FvBlockHandle is not a valid EFI_HANDLE or FvBlock is NULL. 83 84 **/ 85 EFI_STATUS 86 FtwGetFvbByHandle ( 87 IN EFI_HANDLE FvBlockHandle, 88 OUT EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL **FvBlock 89 ) 90 { 91 // 92 // To get the SMM FVB protocol interface on the handle 93 // 94 return gSmst->SmmHandleProtocol ( 95 FvBlockHandle, 96 &gEfiSmmFirmwareVolumeBlockProtocolGuid, 97 (VOID **) FvBlock 98 ); 99 } 100 101 /** 102 Retrive the SMM Swap Address Range protocol interface. 103 104 @param[out] SarProtocol The interface of SMM SAR protocol 105 106 @retval EFI_SUCCESS The SMM SAR protocol instance was found and returned in SarProtocol. 107 @retval EFI_NOT_FOUND The SMM SAR protocol instance was not found. 108 @retval EFI_INVALID_PARAMETER SarProtocol is NULL. 109 110 **/ 111 EFI_STATUS 112 FtwGetSarProtocol ( 113 OUT VOID **SarProtocol 114 ) 115 { 116 EFI_STATUS Status; 117 118 // 119 // Locate Smm Swap Address Range protocol 120 // 121 Status = gSmst->SmmLocateProtocol ( 122 &gEfiSmmSwapAddressRangeProtocolGuid, 123 NULL, 124 SarProtocol 125 ); 126 return Status; 127 } 128 129 /** 130 Function returns an array of handles that support the SMM FVB protocol 131 in a buffer allocated from pool. 132 133 @param[out] NumberHandles The number of handles returned in Buffer. 134 @param[out] Buffer A pointer to the buffer to return the requested 135 array of handles that support SMM FVB protocol. 136 137 @retval EFI_SUCCESS The array of handles was returned in Buffer, and the number of 138 handles in Buffer was returned in NumberHandles. 139 @retval EFI_NOT_FOUND No SMM FVB handle was found. 140 @retval EFI_OUT_OF_RESOURCES There is not enough pool memory to store the matching results. 141 @retval EFI_INVALID_PARAMETER NumberHandles is NULL or Buffer is NULL. 142 143 **/ 144 EFI_STATUS 145 GetFvbCountAndBuffer ( 146 OUT UINTN *NumberHandles, 147 OUT EFI_HANDLE **Buffer 148 ) 149 { 150 EFI_STATUS Status; 151 UINTN BufferSize; 152 153 if ((NumberHandles == NULL) || (Buffer == NULL)) { 154 return EFI_INVALID_PARAMETER; 155 } 156 157 BufferSize = 0; 158 *NumberHandles = 0; 159 *Buffer = NULL; 160 Status = gSmst->SmmLocateHandle ( 161 ByProtocol, 162 &gEfiSmmFirmwareVolumeBlockProtocolGuid, 163 NULL, 164 &BufferSize, 165 *Buffer 166 ); 167 if (EFI_ERROR(Status) && Status != EFI_BUFFER_TOO_SMALL) { 168 return EFI_NOT_FOUND; 169 } 170 171 *Buffer = AllocatePool (BufferSize); 172 if (*Buffer == NULL) { 173 return EFI_OUT_OF_RESOURCES; 174 } 175 176 Status = gSmst->SmmLocateHandle ( 177 ByProtocol, 178 &gEfiSmmFirmwareVolumeBlockProtocolGuid, 179 NULL, 180 &BufferSize, 181 *Buffer 182 ); 183 184 *NumberHandles = BufferSize / sizeof(EFI_HANDLE); 185 if (EFI_ERROR(Status)) { 186 *NumberHandles = 0; 187 FreePool (*Buffer); 188 *Buffer = NULL; 189 } 190 191 return Status; 192 } 193 194 195 /** 196 Get the handle of the SMM FVB protocol by the FVB base address and attributes. 197 198 @param[in] Address The base address of SMM FVB protocol. 199 @param[in] Attributes The attributes of the SMM FVB protocol. 200 @param[out] SmmFvbHandle The handle of the SMM FVB protocol. 201 202 @retval EFI_SUCCESS The FVB handle is found. 203 @retval EFI_ABORTED The FVB protocol is not found. 204 205 **/ 206 EFI_STATUS 207 GetFvbByAddressAndAttribute ( 208 IN EFI_PHYSICAL_ADDRESS Address, 209 IN EFI_FVB_ATTRIBUTES_2 Attributes, 210 OUT EFI_HANDLE *SmmFvbHandle 211 ) 212 { 213 EFI_STATUS Status; 214 EFI_HANDLE *HandleBuffer; 215 UINTN HandleCount; 216 UINTN Index; 217 EFI_PHYSICAL_ADDRESS FvbBaseAddress; 218 EFI_FVB_ATTRIBUTES_2 FvbAttributes; 219 EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL *Fvb; 220 221 HandleBuffer = NULL; 222 223 // 224 // Locate all handles of SMM Fvb protocol. 225 // 226 Status = GetFvbCountAndBuffer (&HandleCount, &HandleBuffer); 227 if (EFI_ERROR (Status)) { 228 return EFI_ABORTED; 229 } 230 231 // 232 // Find the proper SMM Fvb handle by the address and attributes. 233 // 234 for (Index = 0; Index < HandleCount; Index++) { 235 Status = FtwGetFvbByHandle (HandleBuffer[Index], &Fvb); 236 if (EFI_ERROR (Status)) { 237 break; 238 } 239 // 240 // Compare the address. 241 // 242 Status = Fvb->GetPhysicalAddress (Fvb, &FvbBaseAddress); 243 if (EFI_ERROR (Status)) { 244 continue; 245 } 246 if (Address != FvbBaseAddress) { 247 continue; 248 } 249 250 // 251 // Compare the attribute. 252 // 253 Status = Fvb->GetAttributes (Fvb, &FvbAttributes); 254 if (EFI_ERROR (Status)) { 255 continue; 256 } 257 if (Attributes != FvbAttributes) { 258 continue; 259 } 260 261 // 262 // Found the proper FVB handle. 263 // 264 *SmmFvbHandle = HandleBuffer[Index]; 265 FreePool (HandleBuffer); 266 return EFI_SUCCESS; 267 } 268 269 FreePool (HandleBuffer); 270 return EFI_ABORTED; 271 } 272 273 /** 274 Communication service SMI Handler entry. 275 276 This SMI handler provides services for the fault tolerant write wrapper driver. 277 278 Caution: This function requires additional review when modified. 279 This driver need to make sure the CommBuffer is not in the SMRAM range. 280 Also in FTW_FUNCTION_GET_LAST_WRITE case, check SmmFtwGetLastWriteHeader->Data + 281 SmmFtwGetLastWriteHeader->PrivateDataSize within communication buffer. 282 283 @param[in] DispatchHandle The unique handle assigned to this handler by SmiHandlerRegister(). 284 @param[in] RegisterContext Points to an optional handler context which was specified when the 285 handler was registered. 286 @param[in, out] CommBuffer A pointer to a collection of data in memory that will be conveyed 287 from a non-SMM environment into an SMM environment. 288 @param[in, out] CommBufferSize The size of the CommBuffer. 289 290 @retval EFI_SUCCESS The interrupt was handled and quiesced. No other handlers 291 should still be called. 292 @retval EFI_WARN_INTERRUPT_SOURCE_QUIESCED The interrupt has been quiesced but other handlers should 293 still be called. 294 @retval EFI_WARN_INTERRUPT_SOURCE_PENDING The interrupt is still pending and other handlers should still 295 be called. 296 @retval EFI_INTERRUPT_PENDING The interrupt could not be quiesced. 297 298 **/ 299 EFI_STATUS 300 EFIAPI 301 SmmFaultTolerantWriteHandler ( 302 IN EFI_HANDLE DispatchHandle, 303 IN CONST VOID *RegisterContext, 304 IN OUT VOID *CommBuffer, 305 IN OUT UINTN *CommBufferSize 306 ) 307 { 308 EFI_STATUS Status; 309 SMM_FTW_COMMUNICATE_FUNCTION_HEADER *SmmFtwFunctionHeader; 310 SMM_FTW_GET_MAX_BLOCK_SIZE_HEADER *SmmGetMaxBlockSizeHeader; 311 SMM_FTW_ALLOCATE_HEADER *SmmFtwAllocateHeader; 312 SMM_FTW_WRITE_HEADER *SmmFtwWriteHeader; 313 SMM_FTW_RESTART_HEADER *SmmFtwRestartHeader; 314 SMM_FTW_GET_LAST_WRITE_HEADER *SmmFtwGetLastWriteHeader; 315 VOID *PrivateData; 316 EFI_HANDLE SmmFvbHandle; 317 UINTN InfoSize; 318 UINTN CommBufferPayloadSize; 319 UINTN PrivateDataSize; 320 UINTN Length; 321 UINTN TempCommBufferSize; 322 323 // 324 // If input is invalid, stop processing this SMI 325 // 326 if (CommBuffer == NULL || CommBufferSize == NULL) { 327 return EFI_SUCCESS; 328 } 329 330 TempCommBufferSize = *CommBufferSize; 331 332 if (TempCommBufferSize < SMM_FTW_COMMUNICATE_HEADER_SIZE) { 333 DEBUG ((EFI_D_ERROR, "SmmFtwHandler: SMM communication buffer size invalid!\n")); 334 return EFI_SUCCESS; 335 } 336 CommBufferPayloadSize = TempCommBufferSize - SMM_FTW_COMMUNICATE_HEADER_SIZE; 337 338 if (!SmmIsBufferOutsideSmmValid ((UINTN)CommBuffer, TempCommBufferSize)) { 339 DEBUG ((EFI_D_ERROR, "SmmFtwHandler: SMM communication buffer in SMRAM or overflow!\n")); 340 return EFI_SUCCESS; 341 } 342 343 SmmFtwFunctionHeader = (SMM_FTW_COMMUNICATE_FUNCTION_HEADER *)CommBuffer; 344 345 if (mEndOfDxe) { 346 // 347 // It will be not safe to expose the operations after End Of Dxe. 348 // 349 DEBUG ((EFI_D_ERROR, "SmmFtwHandler: Not safe to do the operation: %x after End Of Dxe, so access denied!\n", SmmFtwFunctionHeader->Function)); 350 SmmFtwFunctionHeader->ReturnStatus = EFI_ACCESS_DENIED; 351 return EFI_SUCCESS; 352 } 353 354 switch (SmmFtwFunctionHeader->Function) { 355 case FTW_FUNCTION_GET_MAX_BLOCK_SIZE: 356 if (CommBufferPayloadSize < sizeof (SMM_FTW_GET_MAX_BLOCK_SIZE_HEADER)) { 357 DEBUG ((EFI_D_ERROR, "GetMaxBlockSize: SMM communication buffer size invalid!\n")); 358 return EFI_SUCCESS; 359 } 360 SmmGetMaxBlockSizeHeader = (SMM_FTW_GET_MAX_BLOCK_SIZE_HEADER *) SmmFtwFunctionHeader->Data; 361 362 Status = FtwGetMaxBlockSize ( 363 &mFtwDevice->FtwInstance, 364 &SmmGetMaxBlockSizeHeader->BlockSize 365 ); 366 break; 367 368 case FTW_FUNCTION_ALLOCATE: 369 if (CommBufferPayloadSize < sizeof (SMM_FTW_ALLOCATE_HEADER)) { 370 DEBUG ((EFI_D_ERROR, "Allocate: SMM communication buffer size invalid!\n")); 371 return EFI_SUCCESS; 372 } 373 SmmFtwAllocateHeader = (SMM_FTW_ALLOCATE_HEADER *) SmmFtwFunctionHeader->Data; 374 Status = FtwAllocate ( 375 &mFtwDevice->FtwInstance, 376 &SmmFtwAllocateHeader->CallerId, 377 SmmFtwAllocateHeader->PrivateDataSize, 378 SmmFtwAllocateHeader->NumberOfWrites 379 ); 380 break; 381 382 case FTW_FUNCTION_WRITE: 383 if (CommBufferPayloadSize < OFFSET_OF (SMM_FTW_WRITE_HEADER, Data)) { 384 DEBUG ((EFI_D_ERROR, "Write: SMM communication buffer size invalid!\n")); 385 return EFI_SUCCESS; 386 } 387 SmmFtwWriteHeader = (SMM_FTW_WRITE_HEADER *) SmmFtwFunctionHeader->Data; 388 Length = SmmFtwWriteHeader->Length; 389 PrivateDataSize = SmmFtwWriteHeader->PrivateDataSize; 390 if (((UINTN)(~0) - Length < OFFSET_OF (SMM_FTW_WRITE_HEADER, Data)) || 391 ((UINTN)(~0) - PrivateDataSize < OFFSET_OF (SMM_FTW_WRITE_HEADER, Data) + Length)) { 392 // 393 // Prevent InfoSize overflow 394 // 395 Status = EFI_ACCESS_DENIED; 396 break; 397 } 398 InfoSize = OFFSET_OF (SMM_FTW_WRITE_HEADER, Data) + Length + PrivateDataSize; 399 400 // 401 // SMRAM range check already covered before 402 // 403 if (InfoSize > CommBufferPayloadSize) { 404 DEBUG ((EFI_D_ERROR, "Write: Data size exceed communication buffer size limit!\n")); 405 Status = EFI_ACCESS_DENIED; 406 break; 407 } 408 409 if (PrivateDataSize == 0) { 410 PrivateData = NULL; 411 } else { 412 PrivateData = (VOID *)&SmmFtwWriteHeader->Data[Length]; 413 } 414 Status = GetFvbByAddressAndAttribute ( 415 SmmFtwWriteHeader->FvbBaseAddress, 416 SmmFtwWriteHeader->FvbAttributes, 417 &SmmFvbHandle 418 ); 419 if (!EFI_ERROR (Status)) { 420 Status = FtwWrite( 421 &mFtwDevice->FtwInstance, 422 SmmFtwWriteHeader->Lba, 423 SmmFtwWriteHeader->Offset, 424 Length, 425 PrivateData, 426 SmmFvbHandle, 427 SmmFtwWriteHeader->Data 428 ); 429 } 430 break; 431 432 case FTW_FUNCTION_RESTART: 433 if (CommBufferPayloadSize < sizeof (SMM_FTW_RESTART_HEADER)) { 434 DEBUG ((EFI_D_ERROR, "Restart: SMM communication buffer size invalid!\n")); 435 return EFI_SUCCESS; 436 } 437 SmmFtwRestartHeader = (SMM_FTW_RESTART_HEADER *) SmmFtwFunctionHeader->Data; 438 Status = GetFvbByAddressAndAttribute ( 439 SmmFtwRestartHeader->FvbBaseAddress, 440 SmmFtwRestartHeader->FvbAttributes, 441 &SmmFvbHandle 442 ); 443 if (!EFI_ERROR (Status)) { 444 Status = FtwRestart (&mFtwDevice->FtwInstance, SmmFvbHandle); 445 } 446 break; 447 448 case FTW_FUNCTION_ABORT: 449 Status = FtwAbort (&mFtwDevice->FtwInstance); 450 break; 451 452 case FTW_FUNCTION_GET_LAST_WRITE: 453 if (CommBufferPayloadSize < OFFSET_OF (SMM_FTW_GET_LAST_WRITE_HEADER, Data)) { 454 DEBUG ((EFI_D_ERROR, "GetLastWrite: SMM communication buffer size invalid!\n")); 455 return EFI_SUCCESS; 456 } 457 SmmFtwGetLastWriteHeader = (SMM_FTW_GET_LAST_WRITE_HEADER *) SmmFtwFunctionHeader->Data; 458 PrivateDataSize = SmmFtwGetLastWriteHeader->PrivateDataSize; 459 if ((UINTN)(~0) - PrivateDataSize < OFFSET_OF (SMM_FTW_GET_LAST_WRITE_HEADER, Data)){ 460 // 461 // Prevent InfoSize overflow 462 // 463 Status = EFI_ACCESS_DENIED; 464 break; 465 } 466 InfoSize = OFFSET_OF (SMM_FTW_GET_LAST_WRITE_HEADER, Data) + PrivateDataSize; 467 468 // 469 // SMRAM range check already covered before 470 // 471 if (InfoSize > CommBufferPayloadSize) { 472 DEBUG ((EFI_D_ERROR, "Data size exceed communication buffer size limit!\n")); 473 Status = EFI_ACCESS_DENIED; 474 break; 475 } 476 477 Status = FtwGetLastWrite ( 478 &mFtwDevice->FtwInstance, 479 &SmmFtwGetLastWriteHeader->CallerId, 480 &SmmFtwGetLastWriteHeader->Lba, 481 &SmmFtwGetLastWriteHeader->Offset, 482 &SmmFtwGetLastWriteHeader->Length, 483 &PrivateDataSize, 484 (VOID *)SmmFtwGetLastWriteHeader->Data, 485 &SmmFtwGetLastWriteHeader->Complete 486 ); 487 SmmFtwGetLastWriteHeader->PrivateDataSize = PrivateDataSize; 488 break; 489 490 default: 491 Status = EFI_UNSUPPORTED; 492 } 493 494 SmmFtwFunctionHeader->ReturnStatus = Status; 495 496 return EFI_SUCCESS; 497 } 498 499 500 /** 501 SMM Firmware Volume Block Protocol notification event handler. 502 503 @param[in] Protocol Points to the protocol's unique identifier 504 @param[in] Interface Points to the interface instance 505 @param[in] Handle The handle on which the interface was installed 506 507 @retval EFI_SUCCESS SmmEventCallback runs successfully 508 509 **/ 510 EFI_STATUS 511 EFIAPI 512 FvbNotificationEvent ( 513 IN CONST EFI_GUID *Protocol, 514 IN VOID *Interface, 515 IN EFI_HANDLE Handle 516 ) 517 { 518 EFI_STATUS Status; 519 EFI_SMM_FAULT_TOLERANT_WRITE_PROTOCOL *FtwProtocol; 520 EFI_HANDLE SmmFtwHandle; 521 EFI_HANDLE FtwHandle; 522 523 // 524 // Just return to avoid install SMM FaultTolerantWriteProtocol again 525 // if SMM Fault Tolerant Write protocol had been installed. 526 // 527 Status = gSmst->SmmLocateProtocol ( 528 &gEfiSmmFaultTolerantWriteProtocolGuid, 529 NULL, 530 (VOID **) &FtwProtocol 531 ); 532 if (!EFI_ERROR (Status)) { 533 return EFI_SUCCESS; 534 } 535 536 // 537 // Found proper FVB protocol and initialize FtwDevice for protocol installation 538 // 539 Status = InitFtwProtocol (mFtwDevice); 540 if (EFI_ERROR(Status)) { 541 return Status; 542 } 543 544 // 545 // Install protocol interface 546 // 547 Status = gSmst->SmmInstallProtocolInterface ( 548 &mFtwDevice->Handle, 549 &gEfiSmmFaultTolerantWriteProtocolGuid, 550 EFI_NATIVE_INTERFACE, 551 &mFtwDevice->FtwInstance 552 ); 553 ASSERT_EFI_ERROR (Status); 554 555 /// 556 /// Register SMM FTW SMI handler 557 /// 558 Status = gSmst->SmiHandlerRegister (SmmFaultTolerantWriteHandler, &gEfiSmmFaultTolerantWriteProtocolGuid, &SmmFtwHandle); 559 ASSERT_EFI_ERROR (Status); 560 561 // 562 // Notify the Ftw wrapper driver SMM Ftw is ready 563 // 564 FtwHandle = NULL; 565 Status = gBS->InstallProtocolInterface ( 566 &FtwHandle, 567 &gEfiSmmFaultTolerantWriteProtocolGuid, 568 EFI_NATIVE_INTERFACE, 569 NULL 570 ); 571 ASSERT_EFI_ERROR (Status); 572 573 return EFI_SUCCESS; 574 } 575 576 /** 577 SMM END_OF_DXE protocol notification event handler. 578 579 @param Protocol Points to the protocol's unique identifier 580 @param Interface Points to the interface instance 581 @param Handle The handle on which the interface was installed 582 583 @retval EFI_SUCCESS SmmEndOfDxeCallback runs successfully 584 585 **/ 586 EFI_STATUS 587 EFIAPI 588 SmmEndOfDxeCallback ( 589 IN CONST EFI_GUID *Protocol, 590 IN VOID *Interface, 591 IN EFI_HANDLE Handle 592 ) 593 { 594 mEndOfDxe = TRUE; 595 return EFI_SUCCESS; 596 } 597 598 /** 599 This function is the entry point of the Fault Tolerant Write driver. 600 601 @param[in] ImageHandle A handle for the image that is initializing this driver 602 @param[in] SystemTable A pointer to the EFI system table 603 604 @retval EFI_SUCCESS The initialization finished successfully. 605 @retval EFI_OUT_OF_RESOURCES Allocate memory error 606 @retval EFI_INVALID_PARAMETER Workspace or Spare block does not exist 607 608 **/ 609 EFI_STATUS 610 EFIAPI 611 SmmFaultTolerantWriteInitialize ( 612 IN EFI_HANDLE ImageHandle, 613 IN EFI_SYSTEM_TABLE *SystemTable 614 ) 615 { 616 EFI_STATUS Status; 617 VOID *SmmEndOfDxeRegistration; 618 619 // 620 // Allocate private data structure for SMM FTW protocol and do some initialization 621 // 622 Status = InitFtwDevice (&mFtwDevice); 623 if (EFI_ERROR(Status)) { 624 return Status; 625 } 626 627 // 628 // Register EFI_SMM_END_OF_DXE_PROTOCOL_GUID notify function. 629 // 630 Status = gSmst->SmmRegisterProtocolNotify ( 631 &gEfiSmmEndOfDxeProtocolGuid, 632 SmmEndOfDxeCallback, 633 &SmmEndOfDxeRegistration 634 ); 635 ASSERT_EFI_ERROR (Status); 636 637 // 638 // Register FvbNotificationEvent () notify function. 639 // 640 Status = gSmst->SmmRegisterProtocolNotify ( 641 &gEfiSmmFirmwareVolumeBlockProtocolGuid, 642 FvbNotificationEvent, 643 &mFvbRegistration 644 ); 645 ASSERT_EFI_ERROR (Status); 646 647 FvbNotificationEvent (NULL, NULL, NULL); 648 649 return EFI_SUCCESS; 650 } 651