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   This function check if the address refered by Buffer and Length is valid.
 104
 105   @param Buffer  the buffer address to be checked.
 106   @param Length  the buffer length to be checked.
 107
 108   @retval TRUE  this address is valid.
 109   @retval FALSE this address is NOT valid.
 110 **/
 111 BOOLEAN
 112 InternalIsAddressValid (
 113   IN UINTN                 Buffer,
 114   IN UINTN                 Length
 115   )
 116 {
 117   if (Buffer > (MAX_ADDRESS - Length)) {
 118     //
 119     // Overflow happen
 120     //
 121     return FALSE;
 122   }
 123   if (InternalIsAddressInSmram ((EFI_PHYSICAL_ADDRESS)Buffer, (UINT64)Length)) {
 124     return FALSE;
 125   }
 126   return TRUE;
 127 }
 128
 129 /**
 130   Retrive the SMM FVB protocol interface by HANDLE.
 131
 132   @param[in]  FvBlockHandle     The handle of SMM FVB protocol that provides services for
 133                                 reading, writing, and erasing the target block.
 134   @param[out] FvBlock           The interface of SMM FVB protocol
 135
 136   @retval EFI_SUCCESS           The interface information for the specified protocol was returned.
 137   @retval EFI_UNSUPPORTED       The device does not support the SMM FVB protocol.
 138   @retval EFI_INVALID_PARAMETER FvBlockHandle is not a valid EFI_HANDLE or FvBlock is NULL.
 139
 140 **/
 141 EFI_STATUS
 142 FtwGetFvbByHandle (
 143   IN  EFI_HANDLE                          FvBlockHandle,
 144   OUT EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  **FvBlock
 145   )
 146 {
 147   //
 148   // To get the SMM FVB protocol interface on the handle
 149   //
 150   return gSmst->SmmHandleProtocol (
 151                   FvBlockHandle,
 152                   &gEfiSmmFirmwareVolumeBlockProtocolGuid,
 153                   (VOID **) FvBlock
 154                   );
 155 }
 156
 157 /**
 158   Retrive the SMM Swap Address Range protocol interface.
 159
 160   @param[out] SarProtocol       The interface of SMM SAR protocol
 161
 162   @retval EFI_SUCCESS           The SMM SAR protocol instance was found and returned in SarProtocol.
 163   @retval EFI_NOT_FOUND         The SMM SAR protocol instance was not found.
 164   @retval EFI_INVALID_PARAMETER SarProtocol is NULL.
 165
 166 **/
 167 EFI_STATUS
 168 FtwGetSarProtocol (
 169   OUT VOID                                **SarProtocol
 170   )
 171 {
 172   EFI_STATUS                              Status;
 173
 174   //
 175   // Locate Smm Swap Address Range protocol
 176   //
 177   Status = gSmst->SmmLocateProtocol (
 178                     &gEfiSmmSwapAddressRangeProtocolGuid,
 179                     NULL,
 180                     SarProtocol
 181                     );
 182   return Status;
 183 }
 184
 185 /**
 186   Function returns an array of handles that support the SMM FVB protocol
 187   in a buffer allocated from pool.
 188
 189   @param[out]  NumberHandles    The number of handles returned in Buffer.
 190   @param[out]  Buffer           A pointer to the buffer to return the requested
 191                                 array of  handles that support SMM FVB protocol.
 192
 193   @retval EFI_SUCCESS           The array of handles was returned in Buffer, and the number of
 194                                 handles in Buffer was returned in NumberHandles.
 195   @retval EFI_NOT_FOUND         No SMM FVB handle was found.
 196   @retval EFI_OUT_OF_RESOURCES  There is not enough pool memory to store the matching results.
 197   @retval EFI_INVALID_PARAMETER NumberHandles is NULL or Buffer is NULL.
 198
 199 **/
 200 EFI_STATUS
 201 GetFvbCountAndBuffer (
 202   OUT UINTN                               *NumberHandles,
 203   OUT EFI_HANDLE                          **Buffer
 204   )
 205 {
 206   EFI_STATUS                              Status;
 207   UINTN                                   BufferSize;
 208
 209   if ((NumberHandles == NULL) || (Buffer == NULL)) {
 210     return EFI_INVALID_PARAMETER;
 211   }
 212
 213   BufferSize     = 0;
 214   *NumberHandles = 0;
 215   *Buffer        = NULL;
 216   Status = gSmst->SmmLocateHandle (
 217                     ByProtocol,
 218                     &gEfiSmmFirmwareVolumeBlockProtocolGuid,
 219                     NULL,
 220                     &BufferSize,
 221                     *Buffer
 222                     );
 223   if (EFI_ERROR(Status) && Status != EFI_BUFFER_TOO_SMALL) {
 224     return EFI_NOT_FOUND;
 225   }
 226
 227   *Buffer = AllocatePool (BufferSize);
 228   if (*Buffer == NULL) {
 229     return EFI_OUT_OF_RESOURCES;
 230   }
 231
 232   Status = gSmst->SmmLocateHandle (
 233                     ByProtocol,
 234                     &gEfiSmmFirmwareVolumeBlockProtocolGuid,
 235                     NULL,
 236                     &BufferSize,
 237                     *Buffer
 238                     );
 239
 240   *NumberHandles = BufferSize / sizeof(EFI_HANDLE);
 241   if (EFI_ERROR(Status)) {
 242     *NumberHandles = 0;
 243     FreePool (*Buffer);
 244     *Buffer = NULL;
 245   }
 246
 247   return Status;
 248 }
 249
 250
 251 /**
 252   Get the handle of the SMM FVB protocol by the FVB base address and attributes.
 253
 254   @param[in]  Address       The base address of SMM FVB protocol.
 255   @param[in]  Attributes    The attributes of the SMM FVB protocol.
 256   @param[out] SmmFvbHandle  The handle of the SMM FVB protocol.
 257
 258   @retval  EFI_SUCCESS    The FVB handle is found.
 259   @retval  EFI_ABORTED    The FVB protocol is not found.
 260
 261 **/
 262 EFI_STATUS
 263 GetFvbByAddressAndAttribute (
 264   IN  EFI_PHYSICAL_ADDRESS            Address,
 265   IN  EFI_FVB_ATTRIBUTES_2            Attributes,
 266   OUT EFI_HANDLE                      *SmmFvbHandle
 267   )
 268 {
 269   EFI_STATUS                          Status;
 270   EFI_HANDLE                          *HandleBuffer;
 271   UINTN                               HandleCount;
 272   UINTN                               Index;
 273   EFI_PHYSICAL_ADDRESS                FvbBaseAddress;
 274   EFI_FVB_ATTRIBUTES_2                FvbAttributes;
 275   EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *Fvb;
 276
 277   //
 278   // Locate all handles of SMM Fvb protocol.
 279   //
 280   Status = GetFvbCountAndBuffer (&HandleCount, &HandleBuffer);
 281   if (EFI_ERROR (Status)) {
 282     return EFI_ABORTED;
 283   }
 284
 285   //
 286   // Find the proper SMM Fvb handle by the address and attributes.
 287   //
 288   for (Index = 0; Index < HandleCount; Index++) {
 289     Status = FtwGetFvbByHandle (HandleBuffer[Index], &Fvb);
 290     if (EFI_ERROR (Status)) {
 291       break;
 292     }
 293     //
 294     // Compare the address.
 295     //
 296     Status = Fvb->GetPhysicalAddress (Fvb, &FvbBaseAddress);
 297     if (EFI_ERROR (Status)) {
 298       continue;
 299     }
 300     if (Address != FvbBaseAddress) {
 301      continue;
 302     }
 303
 304     //
 305     // Compare the attribute.
 306     //
 307     Status = Fvb->GetAttributes (Fvb, &FvbAttributes);
 308     if (EFI_ERROR (Status)) {
 309       continue;
 310     }
 311     if (Attributes != FvbAttributes) {
 312      continue;
 313     }
 314
 315     //
 316     // Found the proper FVB handle.
 317     //
 318     *SmmFvbHandle = HandleBuffer[Index];
 319     FreePool (HandleBuffer);
 320     return EFI_SUCCESS;
 321   }
 322
 323   FreePool (HandleBuffer);
 324   return EFI_ABORTED;
 325 }
 326
 327 /**
 328   Communication service SMI Handler entry.
 329
 330   This SMI handler provides services for the fault tolerant write wrapper driver.
 331
 332   Caution: This function requires additional review when modified.
 333   This driver need to make sure the CommBuffer is not in the SMRAM range.
 334   Also in FTW_FUNCTION_GET_LAST_WRITE case, check SmmFtwGetLastWriteHeader->Data +
 335   SmmFtwGetLastWriteHeader->PrivateDataSize within communication buffer.
 336
 337   @param[in]     DispatchHandle  The unique handle assigned to this handler by SmiHandlerRegister().
 338   @param[in]     RegisterContext Points to an optional handler context which was specified when the
 339                                  handler was registered.
 340   @param[in, out] CommBuffer     A pointer to a collection of data in memory that will be conveyed
 341                                  from a non-SMM environment into an SMM environment.
 342   @param[in, out] CommBufferSize The size of the CommBuffer.
 343
 344   @retval EFI_SUCCESS                         The interrupt was handled and quiesced. No other handlers
 345                                               should still be called.
 346   @retval EFI_WARN_INTERRUPT_SOURCE_QUIESCED  The interrupt has been quiesced but other handlers should
 347                                               still be called.
 348   @retval EFI_WARN_INTERRUPT_SOURCE_PENDING   The interrupt is still pending and other handlers should still
 349                                               be called.
 350   @retval EFI_INTERRUPT_PENDING               The interrupt could not be quiesced.
 351
 352 **/
 353 EFI_STATUS
 354 EFIAPI
 355 SmmFaultTolerantWriteHandler (
 356   IN     EFI_HANDLE                                DispatchHandle,
 357   IN     CONST VOID                                *RegisterContext,
 358   IN OUT VOID                                      *CommBuffer,
 359   IN OUT UINTN                                     *CommBufferSize
 360   )
 361 {
 362   EFI_STATUS                                       Status;
 363   SMM_FTW_COMMUNICATE_FUNCTION_HEADER              *SmmFtwFunctionHeader;
 364   SMM_FTW_GET_MAX_BLOCK_SIZE_HEADER                *SmmGetMaxBlockSizeHeader;
 365   SMM_FTW_ALLOCATE_HEADER                          *SmmFtwAllocateHeader;
 366   SMM_FTW_WRITE_HEADER                             *SmmFtwWriteHeader;
 367   SMM_FTW_RESTART_HEADER                           *SmmFtwRestartHeader;
 368   SMM_FTW_GET_LAST_WRITE_HEADER                    *SmmFtwGetLastWriteHeader;
 369   VOID                                             *PrivateData;
 370   EFI_HANDLE                                       SmmFvbHandle;
 371   UINTN                                            InfoSize;
 372
 373
 374   //
 375   // If input is invalid, stop processing this SMI
 376   //
 377   if (CommBuffer == NULL || CommBufferSize == NULL) {
 378     return EFI_SUCCESS;
 379   }
 380
 381   if (*CommBufferSize < SMM_FTW_COMMUNICATE_HEADER_SIZE) {
 382     return EFI_SUCCESS;
 383   }
 384
 385   if (!InternalIsAddressValid ((UINTN)CommBuffer, *CommBufferSize)) {
 386     DEBUG ((EFI_D_ERROR, "SMM communication buffer in SMRAM or overflow!\n"));
 387     return EFI_SUCCESS;
 388   }
 389
 390   SmmFtwFunctionHeader = (SMM_FTW_COMMUNICATE_FUNCTION_HEADER *)CommBuffer;
 391
 392   if (mEndOfDxe) {
 393     //
 394     // It will be not safe to expose the operations after End Of Dxe.
 395     //
 396     DEBUG ((EFI_D_ERROR, "SmmFtwHandler: Not safe to do the operation: %x after End Of Dxe, so access denied!\n", SmmFtwFunctionHeader->Function));
 397     SmmFtwFunctionHeader->ReturnStatus = EFI_ACCESS_DENIED;
 398     return EFI_SUCCESS;
 399   }
 400
 401   switch (SmmFtwFunctionHeader->Function) {
 402     case FTW_FUNCTION_GET_MAX_BLOCK_SIZE:
 403       SmmGetMaxBlockSizeHeader = (SMM_FTW_GET_MAX_BLOCK_SIZE_HEADER *) SmmFtwFunctionHeader->Data;
 404       InfoSize = sizeof (SMM_FTW_GET_MAX_BLOCK_SIZE_HEADER);
 405
 406       //
 407       // SMRAM range check already covered before
 408       //
 409       if (InfoSize > *CommBufferSize - SMM_FTW_COMMUNICATE_HEADER_SIZE) {
 410         DEBUG ((EFI_D_ERROR, "Data size exceed communication buffer size limit!\n"));
 411         Status = EFI_ACCESS_DENIED;
 412         break;
 413       }
 414
 415       Status = FtwGetMaxBlockSize (
 416                  &mFtwDevice->FtwInstance,
 417                  &SmmGetMaxBlockSizeHeader->BlockSize
 418                  );
 419       break;
 420
 421     case FTW_FUNCTION_ALLOCATE:
 422       SmmFtwAllocateHeader = (SMM_FTW_ALLOCATE_HEADER *) SmmFtwFunctionHeader->Data;
 423       Status = FtwAllocate (
 424                  &mFtwDevice->FtwInstance,
 425                  &SmmFtwAllocateHeader->CallerId,
 426                  SmmFtwAllocateHeader->PrivateDataSize,
 427                  SmmFtwAllocateHeader->NumberOfWrites
 428                  );
 429       break;
 430
 431     case FTW_FUNCTION_WRITE:
 432       SmmFtwWriteHeader = (SMM_FTW_WRITE_HEADER *) SmmFtwFunctionHeader->Data;
 433       if (SmmFtwWriteHeader->PrivateDataSize == 0) {
 434         PrivateData = NULL;
 435       } else {
 436         PrivateData = (VOID *)&SmmFtwWriteHeader->Data[SmmFtwWriteHeader->Length];
 437       }
 438       Status = GetFvbByAddressAndAttribute (
 439                  SmmFtwWriteHeader->FvbBaseAddress,
 440                  SmmFtwWriteHeader->FvbAttributes,
 441                  &SmmFvbHandle
 442                  );
 443       if (!EFI_ERROR (Status)) {
 444         Status = FtwWrite(
 445                    &mFtwDevice->FtwInstance,
 446                    SmmFtwWriteHeader->Lba,
 447                    SmmFtwWriteHeader->Offset,
 448                    SmmFtwWriteHeader->Length,
 449                    PrivateData,
 450                    SmmFvbHandle,
 451                    SmmFtwWriteHeader->Data
 452                    );
 453       }
 454       break;
 455
 456     case FTW_FUNCTION_RESTART:
 457       SmmFtwRestartHeader = (SMM_FTW_RESTART_HEADER *) SmmFtwFunctionHeader->Data;
 458       Status = GetFvbByAddressAndAttribute (
 459                  SmmFtwRestartHeader->FvbBaseAddress,
 460                  SmmFtwRestartHeader->FvbAttributes,
 461                  &SmmFvbHandle
 462                  );
 463       if (!EFI_ERROR (Status)) {
 464         Status = FtwRestart (&mFtwDevice->FtwInstance, SmmFvbHandle);
 465       }
 466       break;
 467
 468     case FTW_FUNCTION_ABORT:
 469       Status = FtwAbort (&mFtwDevice->FtwInstance);
 470       break;
 471
 472     case FTW_FUNCTION_GET_LAST_WRITE:
 473       SmmFtwGetLastWriteHeader = (SMM_FTW_GET_LAST_WRITE_HEADER *) SmmFtwFunctionHeader->Data;
 474       if ((UINTN)(~0) - SmmFtwGetLastWriteHeader->PrivateDataSize < OFFSET_OF (SMM_FTW_GET_LAST_WRITE_HEADER, Data)){
 475         //
 476         // Prevent InfoSize overflow
 477         //
 478         Status = EFI_ACCESS_DENIED;
 479         break;
 480       }
 481       InfoSize = OFFSET_OF (SMM_FTW_GET_LAST_WRITE_HEADER, Data) + SmmFtwGetLastWriteHeader->PrivateDataSize;
 482
 483       //
 484       // SMRAM range check already covered before
 485       //
 486       if (InfoSize > *CommBufferSize - SMM_FTW_COMMUNICATE_HEADER_SIZE) {
 487         DEBUG ((EFI_D_ERROR, "Data size exceed communication buffer size limit!\n"));
 488         Status = EFI_ACCESS_DENIED;
 489         break;
 490       }
 491
 492       Status = FtwGetLastWrite (
 493                  &mFtwDevice->FtwInstance,
 494                  &SmmFtwGetLastWriteHeader->CallerId,
 495                  &SmmFtwGetLastWriteHeader->Lba,
 496                  &SmmFtwGetLastWriteHeader->Offset,
 497                  &SmmFtwGetLastWriteHeader->Length,
 498                  &SmmFtwGetLastWriteHeader->PrivateDataSize,
 499                  (VOID *)SmmFtwGetLastWriteHeader->Data,
 500                  &SmmFtwGetLastWriteHeader->Complete
 501                  );
 502       break;
 503
 504     default:
 505       Status = EFI_UNSUPPORTED;
 506   }
 507
 508   SmmFtwFunctionHeader->ReturnStatus = Status;
 509
 510   return EFI_SUCCESS;
 511 }
 512
 513
 514 /**
 515   SMM Firmware Volume Block Protocol notification event handler.
 516
 517   @param[in]  Protocol      Points to the protocol's unique identifier
 518   @param[in]  Interface     Points to the interface instance
 519   @param[in]  Handle        The handle on which the interface was installed
 520
 521   @retval EFI_SUCCESS       SmmEventCallback runs successfully
 522
 523  **/
 524 EFI_STATUS
 525 EFIAPI
 526 FvbNotificationEvent (
 527   IN CONST EFI_GUID                       *Protocol,
 528   IN VOID                                 *Interface,
 529   IN EFI_HANDLE                           Handle
 530   )
 531 {
 532   EFI_STATUS                              Status;
 533   EFI_SMM_FAULT_TOLERANT_WRITE_PROTOCOL   *FtwProtocol;
 534   EFI_HANDLE                              SmmFtwHandle;
 535
 536   //
 537   // Just return to avoid install SMM FaultTolerantWriteProtocol again
 538   // if SMM Fault Tolerant Write protocol had been installed.
 539   //
 540   Status = gSmst->SmmLocateProtocol (
 541                     &gEfiSmmFaultTolerantWriteProtocolGuid,
 542                     NULL,
 543                     (VOID **) &FtwProtocol
 544                     );
 545   if (!EFI_ERROR (Status)) {
 546     return EFI_SUCCESS;
 547   }
 548
 549   //
 550   // Found proper FVB protocol and initialize FtwDevice for protocol installation
 551   //
 552   Status = InitFtwProtocol (mFtwDevice);
 553   if (EFI_ERROR(Status)) {
 554     return Status;
 555   }
 556
 557   //
 558   // Install protocol interface
 559   //
 560   Status = gSmst->SmmInstallProtocolInterface (
 561                     &mFtwDevice->Handle,
 562                     &gEfiSmmFaultTolerantWriteProtocolGuid,
 563                     EFI_NATIVE_INTERFACE,
 564                     &mFtwDevice->FtwInstance
 565                     );
 566   ASSERT_EFI_ERROR (Status);
 567
 568   //
 569   // Notify the Ftw wrapper driver SMM Ftw is ready
 570   //
 571   SmmFtwHandle = NULL;
 572   Status = gBS->InstallProtocolInterface (
 573                   &SmmFtwHandle,
 574                   &gEfiSmmFaultTolerantWriteProtocolGuid,
 575                   EFI_NATIVE_INTERFACE,
 576                   NULL
 577                   );
 578   ASSERT_EFI_ERROR (Status);
 579
 580   return EFI_SUCCESS;
 581 }
 582
 583 /**
 584   SMM END_OF_DXE protocol notification event handler.
 585
 586   @param  Protocol   Points to the protocol's unique identifier
 587   @param  Interface  Points to the interface instance
 588   @param  Handle     The handle on which the interface was installed
 589
 590   @retval EFI_SUCCESS   SmmEndOfDxeCallback runs successfully
 591
 592 **/
 593 EFI_STATUS
 594 EFIAPI
 595 SmmEndOfDxeCallback (
 596   IN CONST EFI_GUID                       *Protocol,
 597   IN VOID                                 *Interface,
 598   IN EFI_HANDLE                           Handle
 599   )
 600 {
 601   mEndOfDxe = TRUE;
 602   return EFI_SUCCESS;
 603 }
 604
 605 /**
 606   This function is the entry point of the Fault Tolerant Write driver.
 607
 608   @param[in] ImageHandle        A handle for the image that is initializing this driver
 609   @param[in] SystemTable        A pointer to the EFI system table
 610
 611   @retval EFI_SUCCESS           The initialization finished successfully.
 612   @retval EFI_OUT_OF_RESOURCES  Allocate memory error
 613   @retval EFI_INVALID_PARAMETER Workspace or Spare block does not exist
 614
 615 **/
 616 EFI_STATUS
 617 EFIAPI
 618 SmmFaultTolerantWriteInitialize (
 619   IN EFI_HANDLE                           ImageHandle,
 620   IN EFI_SYSTEM_TABLE                     *SystemTable
 621   )
 622 {
 623   EFI_STATUS                              Status;
 624   EFI_HANDLE                              FtwHandle;
 625   EFI_SMM_ACCESS2_PROTOCOL                *SmmAccess;
 626   UINTN                                   Size;
 627   VOID                                    *SmmEndOfDxeRegistration;
 628
 629   //
 630   // Allocate private data structure for SMM FTW protocol and do some initialization
 631   //
 632   Status = InitFtwDevice (&mFtwDevice);
 633   if (EFI_ERROR(Status)) {
 634     return Status;
 635   }
 636
 637   //
 638   // Get SMRAM information
 639   //
 640   Status = gBS->LocateProtocol (&gEfiSmmAccess2ProtocolGuid, NULL, (VOID **)&SmmAccess);
 641   ASSERT_EFI_ERROR (Status);
 642
 643   Size = 0;
 644   Status = SmmAccess->GetCapabilities (SmmAccess, &Size, NULL);
 645   ASSERT (Status == EFI_BUFFER_TOO_SMALL);
 646
 647   Status = gSmst->SmmAllocatePool (
 648                     EfiRuntimeServicesData,
 649                     Size,
 650                     (VOID **)&mSmramRanges
 651                     );
 652   ASSERT_EFI_ERROR (Status);
 653
 654   Status = SmmAccess->GetCapabilities (SmmAccess, &Size, mSmramRanges);
 655   ASSERT_EFI_ERROR (Status);
 656
 657   mSmramRangeCount = Size / sizeof (EFI_SMRAM_DESCRIPTOR);
 658
 659   //
 660   // Register EFI_SMM_END_OF_DXE_PROTOCOL_GUID notify function.
 661   //
 662   Status = gSmst->SmmRegisterProtocolNotify (
 663                     &gEfiSmmEndOfDxeProtocolGuid,
 664                     SmmEndOfDxeCallback,
 665                     &SmmEndOfDxeRegistration
 666                     );
 667   ASSERT_EFI_ERROR (Status);
 668
 669   //
 670   // Register FvbNotificationEvent () notify function.
 671   //
 672   Status = gSmst->SmmRegisterProtocolNotify (
 673                     &gEfiSmmFirmwareVolumeBlockProtocolGuid,
 674                     FvbNotificationEvent,
 675                     &mFvbRegistration
 676                     );
 677   ASSERT_EFI_ERROR (Status);
 678
 679   FvbNotificationEvent (NULL, NULL, NULL);
 680
 681   ///
 682   /// Register SMM FTW SMI handler
 683   ///
 684   Status = gSmst->SmiHandlerRegister (SmmFaultTolerantWriteHandler, &gEfiSmmFaultTolerantWriteProtocolGuid, &FtwHandle);
 685   ASSERT_EFI_ERROR (Status);
 686
 687   return EFI_SUCCESS;
 688 }