MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.c

   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 - 2013, 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 <Protocol/SmmSwapAddressRange.h>
  60 #include "FaultTolerantWrite.h"
  61 #include "FaultTolerantWriteSmmCommon.h"
  62 #include <Protocol/SmmAccess2.h>
  63 #include <Protocol/SmmEndOfDxe.h>
  64
  65 EFI_EVENT                                 mFvbRegistration = NULL;
  66 EFI_FTW_DEVICE                            *mFtwDevice      = NULL;
  67 EFI_SMRAM_DESCRIPTOR                      *mSmramRanges;
  68 UINTN                                     mSmramRangeCount;
  69
  70 ///
  71 /// The flag to indicate whether the platform has left the DXE phase of execution.
  72 ///
  73 BOOLEAN                                   mEndOfDxe = FALSE;
  74
  75 /**
  76   This function check if the address is in SMRAM.
  77
  78   @param Buffer  the buffer address to be checked.
  79   @param Length  the buffer length to be checked.
  80
  81   @retval TRUE  this address is in SMRAM.
  82   @retval FALSE this address is NOT in SMRAM.
  83 **/
  84 BOOLEAN
  85 InternalIsAddressInSmram (
  86   IN EFI_PHYSICAL_ADDRESS  Buffer,
  87   IN UINT64                Length
  88   )
  89 {
  90   UINTN  Index;
  91
  92   for (Index = 0; Index < mSmramRangeCount; Index ++) {
  93     if (((Buffer >= mSmramRanges[Index].CpuStart) && (Buffer < mSmramRanges[Index].CpuStart + mSmramRanges[Index].PhysicalSize)) ||
  94         ((mSmramRanges[Index].CpuStart >= Buffer) && (mSmramRanges[Index].CpuStart < Buffer + Length))) {
  95       return TRUE;
  96     }
  97   }
  98
  99   return FALSE;
 100 }
 101
 102
 103 /**
 104   Retrive the SMM FVB protocol interface by HANDLE.
 105
 106   @param[in]  FvBlockHandle     The handle of SMM FVB protocol that provides services for
 107                                 reading, writing, and erasing the target block.
 108   @param[out] FvBlock           The interface of SMM FVB protocol
 109
 110   @retval EFI_SUCCESS           The interface information for the specified protocol was returned.
 111   @retval EFI_UNSUPPORTED       The device does not support the SMM FVB protocol.
 112   @retval EFI_INVALID_PARAMETER FvBlockHandle is not a valid EFI_HANDLE or FvBlock is NULL.
 113
 114 **/
 115 EFI_STATUS
 116 FtwGetFvbByHandle (
 117   IN  EFI_HANDLE                          FvBlockHandle,
 118   OUT EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  **FvBlock
 119   )
 120 {
 121   //
 122   // To get the SMM FVB protocol interface on the handle
 123   //
 124   return gSmst->SmmHandleProtocol (
 125                   FvBlockHandle,
 126                   &gEfiSmmFirmwareVolumeBlockProtocolGuid,
 127                   (VOID **) FvBlock
 128                   );
 129 }
 130
 131 /**
 132   Retrive the SMM Swap Address Range protocol interface.
 133
 134   @param[out] SarProtocol       The interface of SMM SAR protocol
 135
 136   @retval EFI_SUCCESS           The SMM SAR protocol instance was found and returned in SarProtocol.
 137   @retval EFI_NOT_FOUND         The SMM SAR protocol instance was not found.
 138   @retval EFI_INVALID_PARAMETER SarProtocol is NULL.
 139
 140 **/
 141 EFI_STATUS
 142 FtwGetSarProtocol (
 143   OUT VOID                                **SarProtocol
 144   )
 145 {
 146   EFI_STATUS                              Status;
 147
 148   //
 149   // Locate Smm Swap Address Range protocol
 150   //
 151   Status = gSmst->SmmLocateProtocol (
 152                     &gEfiSmmSwapAddressRangeProtocolGuid,
 153                     NULL,
 154                     SarProtocol
 155                     );
 156   return Status;
 157 }
 158
 159 /**
 160   Function returns an array of handles that support the SMM FVB protocol
 161   in a buffer allocated from pool.
 162
 163   @param[out]  NumberHandles    The number of handles returned in Buffer.
 164   @param[out]  Buffer           A pointer to the buffer to return the requested
 165                                 array of  handles that support SMM FVB protocol.
 166
 167   @retval EFI_SUCCESS           The array of handles was returned in Buffer, and the number of
 168                                 handles in Buffer was returned in NumberHandles.
 169   @retval EFI_NOT_FOUND         No SMM FVB handle was found.
 170   @retval EFI_OUT_OF_RESOURCES  There is not enough pool memory to store the matching results.
 171   @retval EFI_INVALID_PARAMETER NumberHandles is NULL or Buffer is NULL.
 172
 173 **/
 174 EFI_STATUS
 175 GetFvbCountAndBuffer (
 176   OUT UINTN                               *NumberHandles,
 177   OUT EFI_HANDLE                          **Buffer
 178   )
 179 {
 180   EFI_STATUS                              Status;
 181   UINTN                                   BufferSize;
 182
 183   if ((NumberHandles == NULL) || (Buffer == NULL)) {
 184     return EFI_INVALID_PARAMETER;
 185   }
 186
 187   BufferSize     = 0;
 188   *NumberHandles = 0;
 189   *Buffer        = NULL;
 190   Status = gSmst->SmmLocateHandle (
 191                     ByProtocol,
 192                     &gEfiSmmFirmwareVolumeBlockProtocolGuid,
 193                     NULL,
 194                     &BufferSize,
 195                     *Buffer
 196                     );
 197   if (EFI_ERROR(Status) && Status != EFI_BUFFER_TOO_SMALL) {
 198     return EFI_NOT_FOUND;
 199   }
 200
 201   *Buffer = AllocatePool (BufferSize);
 202   if (*Buffer == NULL) {
 203     return EFI_OUT_OF_RESOURCES;
 204   }
 205
 206   Status = gSmst->SmmLocateHandle (
 207                     ByProtocol,
 208                     &gEfiSmmFirmwareVolumeBlockProtocolGuid,
 209                     NULL,
 210                     &BufferSize,
 211                     *Buffer
 212                     );
 213
 214   *NumberHandles = BufferSize / sizeof(EFI_HANDLE);
 215   if (EFI_ERROR(Status)) {
 216     *NumberHandles = 0;
 217     FreePool (*Buffer);
 218     *Buffer = NULL;
 219   }
 220
 221   return Status;
 222 }
 223
 224
 225 /**
 226   Get the handle of the SMM FVB protocol by the FVB base address and attributes.
 227
 228   @param[in]  Address       The base address of SMM FVB protocol.
 229   @param[in]  Attributes    The attributes of the SMM FVB protocol.
 230   @param[out] SmmFvbHandle  The handle of the SMM FVB protocol.
 231
 232   @retval  EFI_SUCCESS    The FVB handle is found.
 233   @retval  EFI_ABORTED    The FVB protocol is not found.
 234
 235 **/
 236 EFI_STATUS
 237 GetFvbByAddressAndAttribute (
 238   IN  EFI_PHYSICAL_ADDRESS            Address,
 239   IN  EFI_FVB_ATTRIBUTES_2            Attributes,
 240   OUT EFI_HANDLE                      *SmmFvbHandle
 241   )
 242 {
 243   EFI_STATUS                          Status;
 244   EFI_HANDLE                          *HandleBuffer;
 245   UINTN                               HandleCount;
 246   UINTN                               Index;
 247   EFI_PHYSICAL_ADDRESS                FvbBaseAddress;
 248   EFI_FVB_ATTRIBUTES_2                FvbAttributes;
 249   EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *Fvb;
 250
 251   //
 252   // Locate all handles of SMM Fvb protocol.
 253   //
 254   Status = GetFvbCountAndBuffer (&HandleCount, &HandleBuffer);
 255   if (EFI_ERROR (Status)) {
 256     return EFI_ABORTED;
 257   }
 258
 259   //
 260   // Find the proper SMM Fvb handle by the address and attributes.
 261   //
 262   for (Index = 0; Index < HandleCount; Index++) {
 263     Status = FtwGetFvbByHandle (HandleBuffer[Index], &Fvb);
 264     if (EFI_ERROR (Status)) {
 265       break;
 266     }
 267     //
 268     // Compare the address.
 269     //
 270     Status = Fvb->GetPhysicalAddress (Fvb, &FvbBaseAddress);
 271     if (EFI_ERROR (Status)) {
 272       continue;
 273     }
 274     if (Address != FvbBaseAddress) {
 275      continue;
 276     }
 277
 278     //
 279     // Compare the attribute.
 280     //
 281     Status = Fvb->GetAttributes (Fvb, &FvbAttributes);
 282     if (EFI_ERROR (Status)) {
 283       continue;
 284     }
 285     if (Attributes != FvbAttributes) {
 286      continue;
 287     }
 288
 289     //
 290     // Found the proper FVB handle.
 291     //
 292     *SmmFvbHandle = HandleBuffer[Index];
 293     FreePool (HandleBuffer);
 294     return EFI_SUCCESS;
 295   }
 296
 297   FreePool (HandleBuffer);
 298   return EFI_ABORTED;
 299 }
 300
 301 /**
 302   Communication service SMI Handler entry.
 303
 304   This SMI handler provides services for the fault tolerant write wrapper driver.
 305
 306   Caution: This function requires additional review when modified.
 307   This driver need to make sure the CommBuffer is not in the SMRAM range.
 308   Also in FTW_FUNCTION_GET_LAST_WRITE case, check SmmFtwGetLastWriteHeader->Data +
 309   SmmFtwGetLastWriteHeader->PrivateDataSize within communication buffer.
 310
 311   @param[in]     DispatchHandle  The unique handle assigned to this handler by SmiHandlerRegister().
 312   @param[in]     RegisterContext Points to an optional handler context which was specified when the
 313                                  handler was registered.
 314   @param[in, out] CommBuffer     A pointer to a collection of data in memory that will be conveyed
 315                                  from a non-SMM environment into an SMM environment.
 316   @param[in, out] CommBufferSize The size of the CommBuffer.
 317
 318   @retval EFI_SUCCESS                         The interrupt was handled and quiesced. No other handlers
 319                                               should still be called.
 320   @retval EFI_WARN_INTERRUPT_SOURCE_QUIESCED  The interrupt has been quiesced but other handlers should
 321                                               still be called.
 322   @retval EFI_WARN_INTERRUPT_SOURCE_PENDING   The interrupt is still pending and other handlers should still
 323                                               be called.
 324   @retval EFI_INTERRUPT_PENDING               The interrupt could not be quiesced.
 325
 326 **/
 327 EFI_STATUS
 328 EFIAPI
 329 SmmFaultTolerantWriteHandler (
 330   IN     EFI_HANDLE                                DispatchHandle,
 331   IN     CONST VOID                                *RegisterContext,
 332   IN OUT VOID                                      *CommBuffer,
 333   IN OUT UINTN                                     *CommBufferSize
 334   )
 335 {
 336   EFI_STATUS                                       Status;
 337   SMM_FTW_COMMUNICATE_FUNCTION_HEADER              *SmmFtwFunctionHeader;
 338   SMM_FTW_GET_MAX_BLOCK_SIZE_HEADER                *SmmGetMaxBlockSizeHeader;
 339   SMM_FTW_ALLOCATE_HEADER                          *SmmFtwAllocateHeader;
 340   SMM_FTW_WRITE_HEADER                             *SmmFtwWriteHeader;
 341   SMM_FTW_RESTART_HEADER                           *SmmFtwRestartHeader;
 342   SMM_FTW_GET_LAST_WRITE_HEADER                    *SmmFtwGetLastWriteHeader;
 343   VOID                                             *PrivateData;
 344   EFI_HANDLE                                       SmmFvbHandle;
 345   UINTN                                            InfoSize;
 346
 347
 348   //
 349   // If input is invalid, stop processing this SMI
 350   //
 351   if (CommBuffer == NULL || CommBufferSize == NULL) {
 352     return EFI_SUCCESS;
 353   }
 354
 355   if (*CommBufferSize < SMM_FTW_COMMUNICATE_HEADER_SIZE) {
 356     return EFI_SUCCESS;
 357   }
 358
 359   if (InternalIsAddressInSmram ((EFI_PHYSICAL_ADDRESS)(UINTN)CommBuffer, *CommBufferSize)) {
 360     DEBUG ((EFI_D_ERROR, "SMM communication buffer size is in SMRAM!\n"));
 361     return EFI_SUCCESS;
 362   }
 363
 364   SmmFtwFunctionHeader = (SMM_FTW_COMMUNICATE_FUNCTION_HEADER *)CommBuffer;
 365
 366   if (mEndOfDxe) {
 367     //
 368     // It will be not safe to expose the operations after End Of Dxe.
 369     //
 370     DEBUG ((EFI_D_ERROR, "SmmFtwHandler: Not safe to do the operation: %x after End Of Dxe, so access denied!\n", SmmFtwFunctionHeader->Function));
 371     SmmFtwFunctionHeader->ReturnStatus = EFI_ACCESS_DENIED;
 372     return EFI_SUCCESS;
 373   }
 374
 375   switch (SmmFtwFunctionHeader->Function) {
 376     case FTW_FUNCTION_GET_MAX_BLOCK_SIZE:
 377       SmmGetMaxBlockSizeHeader = (SMM_FTW_GET_MAX_BLOCK_SIZE_HEADER *) SmmFtwFunctionHeader->Data;
 378       InfoSize = sizeof (SMM_FTW_GET_MAX_BLOCK_SIZE_HEADER);
 379
 380       //
 381       // SMRAM range check already covered before
 382       //
 383       if (InfoSize > *CommBufferSize - SMM_FTW_COMMUNICATE_HEADER_SIZE) {
 384         DEBUG ((EFI_D_ERROR, "Data size exceed communication buffer size limit!\n"));
 385         Status = EFI_ACCESS_DENIED;
 386         break;
 387       }
 388
 389       Status = FtwGetMaxBlockSize (
 390                  &mFtwDevice->FtwInstance,
 391                  &SmmGetMaxBlockSizeHeader->BlockSize
 392                  );
 393       break;
 394
 395     case FTW_FUNCTION_ALLOCATE:
 396       SmmFtwAllocateHeader = (SMM_FTW_ALLOCATE_HEADER *) SmmFtwFunctionHeader->Data;
 397       Status = FtwAllocate (
 398                  &mFtwDevice->FtwInstance,
 399                  &SmmFtwAllocateHeader->CallerId,
 400                  SmmFtwAllocateHeader->PrivateDataSize,
 401                  SmmFtwAllocateHeader->NumberOfWrites
 402                  );
 403       break;
 404
 405     case FTW_FUNCTION_WRITE:
 406       SmmFtwWriteHeader = (SMM_FTW_WRITE_HEADER *) SmmFtwFunctionHeader->Data;
 407       if (SmmFtwWriteHeader->PrivateDataSize == 0) {
 408         PrivateData = NULL;
 409       } else {
 410         PrivateData = (VOID *)&SmmFtwWriteHeader->Data[SmmFtwWriteHeader->Length];
 411       }
 412       Status = GetFvbByAddressAndAttribute (
 413                  SmmFtwWriteHeader->FvbBaseAddress,
 414                  SmmFtwWriteHeader->FvbAttributes,
 415                  &SmmFvbHandle
 416                  );
 417       if (!EFI_ERROR (Status)) {
 418         Status = FtwWrite(
 419                    &mFtwDevice->FtwInstance,
 420                    SmmFtwWriteHeader->Lba,
 421                    SmmFtwWriteHeader->Offset,
 422                    SmmFtwWriteHeader->Length,
 423                    PrivateData,
 424                    SmmFvbHandle,
 425                    SmmFtwWriteHeader->Data
 426                    );
 427       }
 428       break;
 429
 430     case FTW_FUNCTION_RESTART:
 431       SmmFtwRestartHeader = (SMM_FTW_RESTART_HEADER *) SmmFtwFunctionHeader->Data;
 432       Status = GetFvbByAddressAndAttribute (
 433                  SmmFtwRestartHeader->FvbBaseAddress,
 434                  SmmFtwRestartHeader->FvbAttributes,
 435                  &SmmFvbHandle
 436                  );
 437       if (!EFI_ERROR (Status)) {
 438         Status = FtwRestart (&mFtwDevice->FtwInstance, SmmFvbHandle);
 439       }
 440       break;
 441
 442     case FTW_FUNCTION_ABORT:
 443       Status = FtwAbort (&mFtwDevice->FtwInstance);
 444       break;
 445
 446     case FTW_FUNCTION_GET_LAST_WRITE:
 447       SmmFtwGetLastWriteHeader = (SMM_FTW_GET_LAST_WRITE_HEADER *) SmmFtwFunctionHeader->Data;
 448       if ((UINTN)(~0) - SmmFtwGetLastWriteHeader->PrivateDataSize < OFFSET_OF (SMM_FTW_GET_LAST_WRITE_HEADER, Data)){
 449         //
 450         // Prevent InfoSize overflow
 451         //
 452         Status = EFI_ACCESS_DENIED;
 453         break;
 454       }
 455       InfoSize = OFFSET_OF (SMM_FTW_GET_LAST_WRITE_HEADER, Data) + SmmFtwGetLastWriteHeader->PrivateDataSize;
 456
 457       //
 458       // SMRAM range check already covered before
 459       //
 460       if (InfoSize > *CommBufferSize - SMM_FTW_COMMUNICATE_HEADER_SIZE) {
 461         DEBUG ((EFI_D_ERROR, "Data size exceed communication buffer size limit!\n"));
 462         Status = EFI_ACCESS_DENIED;
 463         break;
 464       }
 465
 466       Status = FtwGetLastWrite (
 467                  &mFtwDevice->FtwInstance,
 468                  &SmmFtwGetLastWriteHeader->CallerId,
 469                  &SmmFtwGetLastWriteHeader->Lba,
 470                  &SmmFtwGetLastWriteHeader->Offset,
 471                  &SmmFtwGetLastWriteHeader->Length,
 472                  &SmmFtwGetLastWriteHeader->PrivateDataSize,
 473                  (VOID *)SmmFtwGetLastWriteHeader->Data,
 474                  &SmmFtwGetLastWriteHeader->Complete
 475                  );
 476       break;
 477
 478     default:
 479       Status = EFI_UNSUPPORTED;
 480   }
 481
 482   SmmFtwFunctionHeader->ReturnStatus = Status;
 483
 484   return EFI_SUCCESS;
 485 }
 486
 487
 488 /**
 489   SMM Firmware Volume Block Protocol notification event handler.
 490
 491   @param[in]  Protocol      Points to the protocol's unique identifier
 492   @param[in]  Interface     Points to the interface instance
 493   @param[in]  Handle        The handle on which the interface was installed
 494
 495   @retval EFI_SUCCESS       SmmEventCallback runs successfully
 496
 497  **/
 498 EFI_STATUS
 499 EFIAPI
 500 FvbNotificationEvent (
 501   IN CONST EFI_GUID                       *Protocol,
 502   IN VOID                                 *Interface,
 503   IN EFI_HANDLE                           Handle
 504   )
 505 {
 506   EFI_STATUS                              Status;
 507   EFI_SMM_FAULT_TOLERANT_WRITE_PROTOCOL   *FtwProtocol;
 508   EFI_HANDLE                              SmmFtwHandle;
 509
 510   //
 511   // Just return to avoid install SMM FaultTolerantWriteProtocol again
 512   // if SMM Fault Tolerant Write protocol had been installed.
 513   //
 514   Status = gSmst->SmmLocateProtocol (
 515                     &gEfiSmmFaultTolerantWriteProtocolGuid,
 516                     NULL,
 517                     (VOID **) &FtwProtocol
 518                     );
 519   if (!EFI_ERROR (Status)) {
 520     return EFI_SUCCESS;
 521   }
 522
 523   //
 524   // Found proper FVB protocol and initialize FtwDevice for protocol installation
 525   //
 526   Status = InitFtwProtocol (mFtwDevice);
 527   if (EFI_ERROR(Status)) {
 528     return Status;
 529   }
 530
 531   //
 532   // Install protocol interface
 533   //
 534   Status = gSmst->SmmInstallProtocolInterface (
 535                     &mFtwDevice->Handle,
 536                     &gEfiSmmFaultTolerantWriteProtocolGuid,
 537                     EFI_NATIVE_INTERFACE,
 538                     &mFtwDevice->FtwInstance
 539                     );
 540   ASSERT_EFI_ERROR (Status);
 541
 542   //
 543   // Notify the Ftw wrapper driver SMM Ftw is ready
 544   //
 545   SmmFtwHandle = NULL;
 546   Status = gBS->InstallProtocolInterface (
 547                   &SmmFtwHandle,
 548                   &gEfiSmmFaultTolerantWriteProtocolGuid,
 549                   EFI_NATIVE_INTERFACE,
 550                   NULL
 551                   );
 552   ASSERT_EFI_ERROR (Status);
 553
 554   return EFI_SUCCESS;
 555 }
 556
 557 /**
 558   SMM END_OF_DXE protocol notification event handler.
 559
 560   @param  Protocol   Points to the protocol's unique identifier
 561   @param  Interface  Points to the interface instance
 562   @param  Handle     The handle on which the interface was installed
 563
 564   @retval EFI_SUCCESS   SmmEndOfDxeCallback runs successfully
 565
 566 **/
 567 EFI_STATUS
 568 EFIAPI
 569 SmmEndOfDxeCallback (
 570   IN CONST EFI_GUID                       *Protocol,
 571   IN VOID                                 *Interface,
 572   IN EFI_HANDLE                           Handle
 573   )
 574 {
 575   mEndOfDxe = TRUE;
 576   return EFI_SUCCESS;
 577 }
 578
 579 /**
 580   This function is the entry point of the Fault Tolerant Write driver.
 581
 582   @param[in] ImageHandle        A handle for the image that is initializing this driver
 583   @param[in] SystemTable        A pointer to the EFI system table
 584
 585   @retval EFI_SUCCESS           The initialization finished successfully.
 586   @retval EFI_OUT_OF_RESOURCES  Allocate memory error
 587   @retval EFI_INVALID_PARAMETER Workspace or Spare block does not exist
 588
 589 **/
 590 EFI_STATUS
 591 EFIAPI
 592 SmmFaultTolerantWriteInitialize (
 593   IN EFI_HANDLE                           ImageHandle,
 594   IN EFI_SYSTEM_TABLE                     *SystemTable
 595   )
 596 {
 597   EFI_STATUS                              Status;
 598   EFI_HANDLE                              FtwHandle;
 599   EFI_SMM_ACCESS2_PROTOCOL                *SmmAccess;
 600   UINTN                                   Size;
 601   VOID                                    *SmmEndOfDxeRegistration;
 602
 603   //
 604   // Allocate private data structure for SMM FTW protocol and do some initialization
 605   //
 606   Status = InitFtwDevice (&mFtwDevice);
 607   if (EFI_ERROR(Status)) {
 608     return Status;
 609   }
 610
 611   //
 612   // Get SMRAM information
 613   //
 614   Status = gBS->LocateProtocol (&gEfiSmmAccess2ProtocolGuid, NULL, (VOID **)&SmmAccess);
 615   ASSERT_EFI_ERROR (Status);
 616
 617   Size = 0;
 618   Status = SmmAccess->GetCapabilities (SmmAccess, &Size, NULL);
 619   ASSERT (Status == EFI_BUFFER_TOO_SMALL);
 620
 621   Status = gSmst->SmmAllocatePool (
 622                     EfiRuntimeServicesData,
 623                     Size,
 624                     (VOID **)&mSmramRanges
 625                     );
 626   ASSERT_EFI_ERROR (Status);
 627
 628   Status = SmmAccess->GetCapabilities (SmmAccess, &Size, mSmramRanges);
 629   ASSERT_EFI_ERROR (Status);
 630
 631   mSmramRangeCount = Size / sizeof (EFI_SMRAM_DESCRIPTOR);
 632
 633   //
 634   // Register EFI_SMM_END_OF_DXE_PROTOCOL_GUID notify function.
 635   //
 636   Status = gSmst->SmmRegisterProtocolNotify (
 637                     &gEfiSmmEndOfDxeProtocolGuid,
 638                     SmmEndOfDxeCallback,
 639                     &SmmEndOfDxeRegistration
 640                     );
 641   ASSERT_EFI_ERROR (Status);
 642
 643   //
 644   // Register FvbNotificationEvent () notify function.
 645   //
 646   Status = gSmst->SmmRegisterProtocolNotify (
 647                     &gEfiSmmFirmwareVolumeBlockProtocolGuid,
 648                     FvbNotificationEvent,
 649                     &mFvbRegistration
 650                     );
 651   ASSERT_EFI_ERROR (Status);
 652
 653   FvbNotificationEvent (NULL, NULL, NULL);
 654
 655   ///
 656   /// Register SMM FTW SMI handler
 657   ///
 658   Status = gSmst->SmiHandlerRegister (SmmFaultTolerantWriteHandler, &gEfiSmmFaultTolerantWriteProtocolGuid, &FtwHandle);
 659   ASSERT_EFI_ERROR (Status);
 660
 661   return EFI_SUCCESS;
 662 }