summaryrefslogtreecommitdiff
path: root/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWrite.c
blob: 625737eac018affcae37b9f9e6843d9e93bfc1f7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
/** @file

  These are the common Fault Tolerant Write (FTW) functions that are shared 
  by DXE FTW driver and SMM FTW driver.

Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials                          
are licensed and made available under the terms and conditions of the BSD License         
which accompanies this distribution.  The full text of the license may be found at        
http://opensource.org/licenses/bsd-license.php                                            
                                                                                          
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.  

**/

#include "FaultTolerantWrite.h"

//
// Fault Tolerant Write Protocol API
//
/**
  Query the largest block that may be updated in a fault tolerant manner.


  @param This            The pointer to this protocol instance. 
  @param BlockSize       A pointer to a caller allocated UINTN that is updated to
                         indicate the size of the largest block that can be updated.

  @return EFI_SUCCESS   The function completed successfully

**/
EFI_STATUS
EFIAPI
FtwGetMaxBlockSize (
  IN EFI_FAULT_TOLERANT_WRITE_PROTOCOL    *This,
  OUT UINTN                               *BlockSize
  )
{
  EFI_FTW_DEVICE  *FtwDevice;

  if (!FeaturePcdGet(PcdFullFtwServiceEnable)) {
    return EFI_UNSUPPORTED;
  }

  FtwDevice   = FTW_CONTEXT_FROM_THIS (This);

  *BlockSize  = FtwDevice->SpareAreaLength;

  return EFI_SUCCESS;
}

/**
  Allocates space for the protocol to maintain information about writes.
  Since writes must be completed in a fault tolerant manner and multiple
  updates will require more resources to be successful, this function
  enables the protocol to ensure that enough space exists to track
  information about the upcoming writes.

  All writes must be completed or aborted before another fault tolerant write can occur.

  @param This            The pointer to this protocol instance. 
  @param CallerId        The GUID identifying the write.
  @param PrivateDataSize The size of the caller's private data
                         that must be recorded for each write.
  @param NumberOfWrites  The number of fault tolerant block writes
                         that will need to occur.

  @return EFI_SUCCESS        The function completed successfully
  @retval EFI_ABORTED        The function could not complete successfully.
  @retval EFI_ACCESS_DENIED  All allocated writes have not been completed.

**/
EFI_STATUS
EFIAPI
FtwAllocate (
  IN EFI_FAULT_TOLERANT_WRITE_PROTOCOL    *This,
  IN EFI_GUID                             *CallerId,
  IN UINTN                                PrivateDataSize,
  IN UINTN                                NumberOfWrites
  )
{
  EFI_STATUS                      Status;
  UINTN                           Length;
  UINTN                           Offset;
  EFI_FTW_DEVICE                  *FtwDevice;
  EFI_FAULT_TOLERANT_WRITE_HEADER *FtwHeader;

  FtwDevice = FTW_CONTEXT_FROM_THIS (This);

  Status    = WorkSpaceRefresh (FtwDevice);
  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }
  //
  // Check if there is enough space for the coming allocation
  //
  if (WRITE_TOTAL_SIZE (NumberOfWrites, PrivateDataSize) > FtwDevice->FtwWorkSpaceHeader->WriteQueueSize) {
    DEBUG ((EFI_D_ERROR, "Ftw: Allocate() request exceed Workspace, Caller: %g\n", CallerId));
    return EFI_BUFFER_TOO_SMALL;
  }
  //
  // Find the last write header and record.
  // If the FtwHeader is complete, skip the completed last write header/records
  //
  FtwHeader = FtwDevice->FtwLastWriteHeader;

  //
  // Previous write has not completed, access denied.
  //
  if ((FtwHeader->HeaderAllocated == FTW_VALID_STATE) || (FtwHeader->WritesAllocated == FTW_VALID_STATE)) {
    return EFI_ACCESS_DENIED;
  }
  //
  // If workspace is not enough, then reclaim workspace
  //
  Offset = (UINT8 *) FtwHeader - (UINT8 *) FtwDevice->FtwWorkSpace;
  if (Offset + WRITE_TOTAL_SIZE (NumberOfWrites, PrivateDataSize) > FtwDevice->FtwWorkSpaceSize) {
    Status = FtwReclaimWorkSpace (FtwDevice, TRUE);
    if (EFI_ERROR (Status)) {
      return EFI_ABORTED;
    }

    FtwHeader = FtwDevice->FtwLastWriteHeader;
  }
  //
  // Prepare FTW write header,
  // overwrite the buffer and write to workspace.
  //
  FtwHeader->WritesAllocated  = FTW_INVALID_STATE;
  FtwHeader->Complete         = FTW_INVALID_STATE;
  CopyMem (&FtwHeader->CallerId, CallerId, sizeof (EFI_GUID));
  FtwHeader->NumberOfWrites   = NumberOfWrites;
  FtwHeader->PrivateDataSize  = PrivateDataSize;
  FtwHeader->HeaderAllocated  = FTW_VALID_STATE;

  Length                      = sizeof (EFI_FAULT_TOLERANT_WRITE_HEADER);
  Status = FtwDevice->FtwFvBlock->Write (
                                    FtwDevice->FtwFvBlock,
                                    FtwDevice->FtwWorkSpaceLba,
                                    FtwDevice->FtwWorkSpaceBase + Offset,
                                    &Length,
                                    (UINT8 *) FtwHeader
                                    );
  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }
  //
  // Update Header->WriteAllocated as VALID
  //
  Status = FtwUpdateFvState (
            FtwDevice->FtwFvBlock,
            FtwDevice->FtwWorkSpaceLba,
            FtwDevice->FtwWorkSpaceBase + Offset,
            WRITES_ALLOCATED
            );
  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }

  DEBUG (
    (EFI_D_ERROR,
    "Ftw: Allocate() success, Caller:%g, # %d\n",
    CallerId,
    NumberOfWrites)
    );

  return EFI_SUCCESS;
}


/**
  Write a record with fault tolerant mannaer.
  Since the content has already backuped in spare block, the write is
  guaranteed to be completed with fault tolerant manner.

  @param This            The pointer to this protocol instance. 
  @param Fvb             The FVB protocol that provides services for
                         reading, writing, and erasing the target block.

  @retval  EFI_SUCCESS          The function completed successfully
  @retval  EFI_ABORTED          The function could not complete successfully

**/
EFI_STATUS
FtwWriteRecord (
  IN EFI_FAULT_TOLERANT_WRITE_PROTOCOL     *This,
  IN EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL    *Fvb
  )
{
  EFI_STATUS                      Status;
  EFI_FTW_DEVICE                  *FtwDevice;
  EFI_FAULT_TOLERANT_WRITE_HEADER *Header;
  EFI_FAULT_TOLERANT_WRITE_RECORD *Record;
  UINTN                           Offset;

  FtwDevice = FTW_CONTEXT_FROM_THIS (This);

  //
  // Spare Complete but Destination not complete,
  // Recover the target block with the spare block.
  //
  Header  = FtwDevice->FtwLastWriteHeader;
  Record  = FtwDevice->FtwLastWriteRecord;

  //
  // IF target block is working block, THEN Flush Spare Block To Working Block;
  // ELSE flush spare block to target block, which may be boot block after all.
  //
  if (IsWorkingBlock (FtwDevice, Fvb, Record->Lba)) {
    //
    // If target block is working block,
    // it also need to set SPARE_COMPLETED to spare block.
    //
    Offset = (UINT8 *) Record - FtwDevice->FtwWorkSpace;
    Status = FtwUpdateFvState (
              FtwDevice->FtwBackupFvb,
              FtwDevice->FtwWorkSpaceLba,
              FtwDevice->FtwWorkSpaceBase + Offset,
              SPARE_COMPLETED
              );
    if (EFI_ERROR (Status)) {
      return EFI_ABORTED;
    }

    Status = FlushSpareBlockToWorkingBlock (FtwDevice);
  } else if (IsBootBlock (FtwDevice, Fvb, Record->Lba)) {
    //
    // Update boot block
    //
    Status = FlushSpareBlockToBootBlock (FtwDevice);
  } else {
    //
    // Update blocks other than working block or boot block
    //
    Status = FlushSpareBlockToTargetBlock (FtwDevice, Fvb, Record->Lba);
  }

  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }
  //
  // Record the DestionationComplete in record
  //
  Offset = (UINT8 *) Record - FtwDevice->FtwWorkSpace;
  Status = FtwUpdateFvState (
            FtwDevice->FtwFvBlock,
            FtwDevice->FtwWorkSpaceLba,
            FtwDevice->FtwWorkSpaceBase + Offset,
            DEST_COMPLETED
            );
  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }

  Record->DestinationComplete = FTW_VALID_STATE;

  //
  // If this is the last Write in these write sequence,
  // set the complete flag of write header.
  //
  if (IsLastRecordOfWrites (Header, Record)) {
    Offset = (UINT8 *) Header - FtwDevice->FtwWorkSpace;
    Status = FtwUpdateFvState (
              FtwDevice->FtwFvBlock,
              FtwDevice->FtwWorkSpaceLba,
              FtwDevice->FtwWorkSpaceBase + Offset,
              WRITES_COMPLETED
              );
    Header->Complete = FTW_VALID_STATE;
    if (EFI_ERROR (Status)) {
      return EFI_ABORTED;
    }
  }

  return EFI_SUCCESS;
}

/**
  Starts a target block update. This function will record data about write
  in fault tolerant storage and will complete the write in a recoverable
  manner, ensuring at all times that either the original contents or
  the modified contents are available.

  @param This            The pointer to this protocol instance. 
  @param Lba             The logical block address of the target block.
  @param Offset          The offset within the target block to place the data.
  @param Length          The number of bytes to write to the target block.
  @param PrivateData     A pointer to private data that the caller requires to
                         complete any pending writes in the event of a fault.
  @param FvBlockHandle   The handle of FVB protocol that provides services for
                         reading, writing, and erasing the target block.
  @param Buffer          The data to write.

  @retval EFI_SUCCESS          The function completed successfully 
  @retval EFI_ABORTED          The function could not complete successfully. 
  @retval EFI_BAD_BUFFER_SIZE  The input data can't fit within the spare block. 
                               Offset + *NumBytes > SpareAreaLength.
  @retval EFI_ACCESS_DENIED    No writes have been allocated. 
  @retval EFI_OUT_OF_RESOURCES Cannot allocate enough memory resource.
  @retval EFI_NOT_FOUND        Cannot find FVB protocol by handle.

**/
EFI_STATUS
EFIAPI
FtwWrite (
  IN EFI_FAULT_TOLERANT_WRITE_PROTOCOL     *This,
  IN EFI_LBA                               Lba,
  IN UINTN                                 Offset,
  IN UINTN                                 Length,
  IN VOID                                  *PrivateData,
  IN EFI_HANDLE                            FvBlockHandle,
  IN VOID                                  *Buffer
  )
{
  EFI_STATUS                          Status;
  EFI_FTW_DEVICE                      *FtwDevice;
  EFI_FAULT_TOLERANT_WRITE_HEADER     *Header;
  EFI_FAULT_TOLERANT_WRITE_RECORD     *Record;
  EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *Fvb;
  UINTN                               MyLength;
  UINTN                               MyOffset;
  UINTN                               MyBufferSize;
  UINT8                               *MyBuffer;
  UINTN                               SpareBufferSize;
  UINT8                               *SpareBuffer;
  UINTN                               Index;
  UINT8                               *Ptr;
  EFI_PHYSICAL_ADDRESS                FvbPhysicalAddress;

  FtwDevice = FTW_CONTEXT_FROM_THIS (This);

  Status    = WorkSpaceRefresh (FtwDevice);
  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }

  Header  = FtwDevice->FtwLastWriteHeader;
  Record  = FtwDevice->FtwLastWriteRecord;
  
  if (IsErasedFlashBuffer ((UINT8 *) Header, sizeof (EFI_FAULT_TOLERANT_WRITE_HEADER))) {
    if (PrivateData == NULL) {
      //
      // Ftw Write Header is not allocated.
      // No additional private data, the private data size is zero. Number of record can be set to 1.
      //
      Status = FtwAllocate (This, &gEfiCallerIdGuid, 0, 1);
      if (EFI_ERROR (Status)) {
        return Status;
      }
    } else {
      //
      // Ftw Write Header is not allocated
      // Additional private data is not NULL, the private data size can't be determined.
      //
      DEBUG ((EFI_D_ERROR, "Ftw: no allocates space for write record!\n"));
      DEBUG ((EFI_D_ERROR, "Ftw: Allocate service should be called before Write service!\n"));
      return EFI_NOT_READY;
    }
  }

  //
  // If Record is out of the range of Header, return access denied.
  //
  if (((UINTN)((UINT8 *) Record - (UINT8 *) Header)) > WRITE_TOTAL_SIZE (Header->NumberOfWrites - 1, Header->PrivateDataSize)) {
    return EFI_ACCESS_DENIED;
  }

  //
  // Check the COMPLETE flag of last write header
  //
  if (Header->Complete == FTW_VALID_STATE) {
    return EFI_ACCESS_DENIED;
  }

  if (Record->DestinationComplete == FTW_VALID_STATE) {
    return EFI_ACCESS_DENIED;
  }

  if ((Record->SpareComplete == FTW_VALID_STATE) && (Record->DestinationComplete != FTW_VALID_STATE)) {
    return EFI_NOT_READY;
  }
  //
  // Check if the input data can fit within the target block
  //
  if ((Offset + Length) > FtwDevice->SpareAreaLength) {
    return EFI_BAD_BUFFER_SIZE;
  }
  //
  // Get the FVB protocol by handle
  //
  Status = FtwGetFvbByHandle (FvBlockHandle, &Fvb);
  if (EFI_ERROR (Status)) {
    return EFI_NOT_FOUND;
  }

  Status = Fvb->GetPhysicalAddress (Fvb, &FvbPhysicalAddress);
  if (EFI_ERROR (Status)) {
    DEBUG ((EFI_D_ERROR, "FtwLite: Get FVB physical address - %r\n", Status));
    return EFI_ABORTED;
  }

  //
  // Set BootBlockUpdate FLAG if it's updating boot block.
  //
  if (IsBootBlock (FtwDevice, Fvb, Lba)) {
    Record->BootBlockUpdate = FTW_VALID_STATE;
  }
  //
  // Write the record to the work space.
  //
  Record->Lba     = Lba;
  Record->Offset  = Offset;
  Record->Length  = Length;
  Record->FvBaseAddress = FvbPhysicalAddress;
  if (PrivateData != NULL) {
    CopyMem ((Record + 1), PrivateData, Header->PrivateDataSize);
  }

  MyOffset  = (UINT8 *) Record - FtwDevice->FtwWorkSpace;
  MyLength  = RECORD_SIZE (Header->PrivateDataSize);

  Status = FtwDevice->FtwFvBlock->Write (
                                    FtwDevice->FtwFvBlock,
                                    FtwDevice->FtwWorkSpaceLba,
                                    FtwDevice->FtwWorkSpaceBase + MyOffset,
                                    &MyLength,
                                    (UINT8 *) Record
                                    );
  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }
  //
  // Record has written to working block, then do the data.
  //
  //
  // Allocate a memory buffer
  //
  MyBufferSize  = FtwDevice->SpareAreaLength;
  MyBuffer      = AllocatePool (MyBufferSize);
  if (MyBuffer == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }
  //
  // Read all original data from target block to memory buffer
  //
  Ptr = MyBuffer;
  for (Index = 0; Index < FtwDevice->NumberOfSpareBlock; Index += 1) {
    MyLength  = FtwDevice->BlockSize;
    Status    = Fvb->Read (Fvb, Lba + Index, 0, &MyLength, Ptr);
    if (EFI_ERROR (Status)) {
      FreePool (MyBuffer);
      return EFI_ABORTED;
    }

    Ptr += MyLength;
  }
  //
  // Overwrite the updating range data with
  // the input buffer content
  //
  CopyMem (MyBuffer + Offset, Buffer, Length);

  //
  // Try to keep the content of spare block
  // Save spare block into a spare backup memory buffer (Sparebuffer)
  //
  SpareBufferSize = FtwDevice->SpareAreaLength;
  SpareBuffer     = AllocatePool (SpareBufferSize);
  if (SpareBuffer == NULL) {
    FreePool (MyBuffer);
    return EFI_OUT_OF_RESOURCES;
  }

  Ptr = SpareBuffer;
  for (Index = 0; Index < FtwDevice->NumberOfSpareBlock; Index += 1) {
    MyLength = FtwDevice->BlockSize;
    Status = FtwDevice->FtwBackupFvb->Read (
                                        FtwDevice->FtwBackupFvb,
                                        FtwDevice->FtwSpareLba + Index,
                                        0,
                                        &MyLength,
                                        Ptr
                                        );
    if (EFI_ERROR (Status)) {
      FreePool (MyBuffer);
      FreePool (SpareBuffer);
      return EFI_ABORTED;
    }

    Ptr += MyLength;
  }
  //
  // Write the memory buffer to spare block
  //
  Status  = FtwEraseSpareBlock (FtwDevice);
  Ptr     = MyBuffer;
  for (Index = 0; Index < FtwDevice->NumberOfSpareBlock; Index += 1) {
    MyLength = FtwDevice->BlockSize;
    Status = FtwDevice->FtwBackupFvb->Write (
                                        FtwDevice->FtwBackupFvb,
                                        FtwDevice->FtwSpareLba + Index,
                                        0,
                                        &MyLength,
                                        Ptr
                                        );
    if (EFI_ERROR (Status)) {
      FreePool (MyBuffer);
      FreePool (SpareBuffer);
      return EFI_ABORTED;
    }

    Ptr += MyLength;
  }
  //
  // Free MyBuffer
  //
  FreePool (MyBuffer);

  //
  // Set the SpareComplete in the FTW record,
  //
  MyOffset = (UINT8 *) Record - FtwDevice->FtwWorkSpace;
  Status = FtwUpdateFvState (
            FtwDevice->FtwFvBlock,
            FtwDevice->FtwWorkSpaceLba,
            FtwDevice->FtwWorkSpaceBase + MyOffset,
            SPARE_COMPLETED
            );
  if (EFI_ERROR (Status)) {
    FreePool (SpareBuffer);
    return EFI_ABORTED;
  }

  Record->SpareComplete = FTW_VALID_STATE;

  //
  //  Since the content has already backuped in spare block, the write is
  //  guaranteed to be completed with fault tolerant manner.
  //
  Status = FtwWriteRecord (This, Fvb);
  if (EFI_ERROR (Status)) {
    FreePool (SpareBuffer);
    return EFI_ABORTED;
  }
  //
  // Restore spare backup buffer into spare block , if no failure happened during FtwWrite.
  //
  Status  = FtwEraseSpareBlock (FtwDevice);
  Ptr     = SpareBuffer;
  for (Index = 0; Index < FtwDevice->NumberOfSpareBlock; Index += 1) {
    MyLength = FtwDevice->BlockSize;
    Status = FtwDevice->FtwBackupFvb->Write (
                                        FtwDevice->FtwBackupFvb,
                                        FtwDevice->FtwSpareLba + Index,
                                        0,
                                        &MyLength,
                                        Ptr
                                        );
    if (EFI_ERROR (Status)) {
      FreePool (SpareBuffer);
      return EFI_ABORTED;
    }

    Ptr += MyLength;
  }
  //
  // All success.
  //
  FreePool (SpareBuffer);

  DEBUG (
    (EFI_D_ERROR,
    "Ftw: Write() success, (Lba:Offset)=(%lx:0x%x), Length: 0x%x\n",
    Lba,
    Offset,
    Length)
    );

  return EFI_SUCCESS;
}

/**
  Restarts a previously interrupted write. The caller must provide the
  block protocol needed to complete the interrupted write.

  @param This            The pointer to this protocol instance. 
  @param FvBlockHandle   The handle of FVB protocol that provides services for
                         reading, writing, and erasing the target block.

  @retval  EFI_SUCCESS          The function completed successfully
  @retval  EFI_ACCESS_DENIED    No pending writes exist
  @retval  EFI_NOT_FOUND        FVB protocol not found by the handle
  @retval  EFI_ABORTED          The function could not complete successfully

**/
EFI_STATUS
EFIAPI
FtwRestart (
  IN EFI_FAULT_TOLERANT_WRITE_PROTOCOL     *This,
  IN EFI_HANDLE                            FvBlockHandle
  )
{
  EFI_STATUS                          Status;
  EFI_FTW_DEVICE                      *FtwDevice;
  EFI_FAULT_TOLERANT_WRITE_HEADER     *Header;
  EFI_FAULT_TOLERANT_WRITE_RECORD     *Record;
  EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *Fvb;

  FtwDevice = FTW_CONTEXT_FROM_THIS (This);

  Status    = WorkSpaceRefresh (FtwDevice);
  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }

  Header  = FtwDevice->FtwLastWriteHeader;
  Record  = FtwDevice->FtwLastWriteRecord;

  //
  // Spare Complete but Destination not complete,
  // Recover the targt block with the spare block.
  //
  Status = FtwGetFvbByHandle (FvBlockHandle, &Fvb);
  if (EFI_ERROR (Status)) {
    return EFI_NOT_FOUND;
  }

  //
  // Check the COMPLETE flag of last write header
  //
  if (Header->Complete == FTW_VALID_STATE) {
    return EFI_ACCESS_DENIED;
  }

  //
  // Check the flags of last write record
  //
  if (Record->DestinationComplete == FTW_VALID_STATE) {
    return EFI_ACCESS_DENIED;
  }

  if ((Record->SpareComplete != FTW_VALID_STATE)) {
    return EFI_ABORTED;
  }

  //
  //  Since the content has already backuped in spare block, the write is
  //  guaranteed to be completed with fault tolerant manner.
  //
  Status = FtwWriteRecord (This, Fvb);
  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }

  //
  // Erase Spare block
  // This is restart, no need to keep spareblock content.
  //
  FtwEraseSpareBlock (FtwDevice);

  DEBUG ((EFI_D_ERROR, "Ftw: Restart() success \n"));
  return EFI_SUCCESS;
}

/**
  Aborts all previous allocated writes.

  @param This                  The pointer to this protocol instance. 

  @retval EFI_SUCCESS          The function completed successfully
  @retval EFI_ABORTED          The function could not complete successfully.
  @retval EFI_NOT_FOUND        No allocated writes exist.

**/
EFI_STATUS
EFIAPI
FtwAbort (
  IN EFI_FAULT_TOLERANT_WRITE_PROTOCOL     *This
  )
{
  EFI_STATUS      Status;
  UINTN           Offset;
  EFI_FTW_DEVICE  *FtwDevice;

  FtwDevice = FTW_CONTEXT_FROM_THIS (This);

  Status    = WorkSpaceRefresh (FtwDevice);
  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }

  if (FtwDevice->FtwLastWriteHeader->Complete == FTW_VALID_STATE) {
    return EFI_NOT_FOUND;
  }
  //
  // Update the complete state of the header as VALID and abort.
  //
  Offset = (UINT8 *) FtwDevice->FtwLastWriteHeader - FtwDevice->FtwWorkSpace;
  Status = FtwUpdateFvState (
            FtwDevice->FtwFvBlock,
            FtwDevice->FtwWorkSpaceLba,
            FtwDevice->FtwWorkSpaceBase + Offset,
            WRITES_COMPLETED
            );
  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }

  FtwDevice->FtwLastWriteHeader->Complete = FTW_VALID_STATE;

  DEBUG ((EFI_D_ERROR, "Ftw: Abort() success \n"));
  return EFI_SUCCESS;
}

/**
  Starts a target block update. This records information about the write
  in fault tolerant storage and will complete the write in a recoverable
  manner, ensuring at all times that either the original contents or
  the modified contents are available.

  @param This            The pointer to this protocol instance. 
  @param CallerId        The GUID identifying the last write.
  @param Lba             The logical block address of the last write.
  @param Offset          The offset within the block of the last write.
  @param Length          The length of the last write.
  @param PrivateDataSize bytes from the private data
                         stored for this write.
  @param PrivateData     A pointer to a buffer. The function will copy
  @param Complete        A Boolean value with TRUE indicating
                         that the write was completed.

  @retval EFI_SUCCESS           The function completed successfully
  @retval EFI_ABORTED           The function could not complete successfully
  @retval EFI_NOT_FOUND         No allocated writes exist
  @retval EFI_BUFFER_TOO_SMALL  Input buffer is not larget enough

**/
EFI_STATUS
EFIAPI
FtwGetLastWrite (
  IN EFI_FAULT_TOLERANT_WRITE_PROTOCOL     *This,
  OUT EFI_GUID                             *CallerId,
  OUT EFI_LBA                              *Lba,
  OUT UINTN                                *Offset,
  OUT UINTN                                *Length,
  IN OUT UINTN                             *PrivateDataSize,
  OUT VOID                                 *PrivateData,
  OUT BOOLEAN                              *Complete
  )
{
  EFI_STATUS                      Status;
  EFI_FTW_DEVICE                  *FtwDevice;
  EFI_FAULT_TOLERANT_WRITE_HEADER *Header;
  EFI_FAULT_TOLERANT_WRITE_RECORD *Record;

  if (!FeaturePcdGet(PcdFullFtwServiceEnable)) {
    return EFI_UNSUPPORTED;
  }

  FtwDevice = FTW_CONTEXT_FROM_THIS (This);

  Status    = WorkSpaceRefresh (FtwDevice);
  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }

  Header  = FtwDevice->FtwLastWriteHeader;
  Record  = FtwDevice->FtwLastWriteRecord;

  //
  // If Header is incompleted and the last record has completed, then
  // call Abort() to set the Header->Complete FLAG.
  //
  if ((Header->Complete != FTW_VALID_STATE) &&
      (Record->DestinationComplete == FTW_VALID_STATE) &&
      IsLastRecordOfWrites (Header, Record)
        ) {

    Status    = FtwAbort (This);
    *Complete = TRUE;
    return EFI_NOT_FOUND;
  }
  //
  // If there is no write header/record, return not found.
  //
  if (Header->HeaderAllocated != FTW_VALID_STATE) {
    *Complete = TRUE;
    return EFI_NOT_FOUND;
  }
  //
  // If this record SpareComplete has not set, then it can not restart.
  //
  if (Record->SpareComplete != FTW_VALID_STATE) {
    Status = GetPreviousRecordOfWrites (Header, &Record);
    if (EFI_ERROR (Status)) {
      FtwAbort (This);
      *Complete = TRUE;
      return EFI_NOT_FOUND;
    }
    ASSERT (Record != NULL);
  }

  //
  // Fill all the requested values
  //
  CopyMem (CallerId, &Header->CallerId, sizeof (EFI_GUID));
  *Lba      = Record->Lba;
  *Offset   = Record->Offset;
  *Length   = Record->Length;
  *Complete = (BOOLEAN) (Record->DestinationComplete == FTW_VALID_STATE);

  if (*PrivateDataSize < Header->PrivateDataSize) {
    *PrivateDataSize  = Header->PrivateDataSize;
    PrivateData       = NULL;
    Status            = EFI_BUFFER_TOO_SMALL;
  } else {
    *PrivateDataSize = Header->PrivateDataSize;
    CopyMem (PrivateData, Record + 1, *PrivateDataSize);
    Status = EFI_SUCCESS;
  }

  DEBUG ((EFI_D_ERROR, "Ftw: GetLasetWrite() success\n"));

  return Status;
}