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