summaryrefslogtreecommitdiff
path: root/InOsEmuPkg/EmuSimpleFileSystemDxe/EmuSimpleFileSystem.c
blob: ba032614332bf2c37919d6e3cf664c61def839c5 (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
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
/*++ @file
  Produce Simple File System abstractions for directories on your PC using Posix APIs.
  The configuration of what devices to mount or emulate comes from UNIX 
  environment variables. The variables must be visible to the Microsoft* 
  Developer Studio for them to work.

Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
Portions copyright (c) 2011, Apple Inc. All rights reserved.
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 "EmuSimpleFileSystem.h"




/**
  Opens a new file relative to the source file's location.

  @param  This       The protocol instance pointer.
  @param  NewHandle  Returns File Handle for FileName.
  @param  FileName   Null terminated string. "\", ".", and ".." are supported.
  @param  OpenMode   Open mode for file.
  @param  Attributes Only used for EFI_FILE_MODE_CREATE.

  @retval EFI_SUCCESS          The device was opened.
  @retval EFI_NOT_FOUND        The specified file could not be found on the device.
  @retval EFI_NO_MEDIA         The device has no media.
  @retval EFI_MEDIA_CHANGED    The media has changed.
  @retval EFI_DEVICE_ERROR     The device reported an error.
  @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
  @retval EFI_ACCESS_DENIED    The service denied access to the file.
  @retval EFI_OUT_OF_RESOURCES The volume was not opened due to lack of resources.
  @retval EFI_VOLUME_FULL      The volume is full.

**/
EFI_STATUS
EFIAPI
EmuSimpleFileSystemOpen (
  IN  EFI_FILE_PROTOCOL   *This,
  OUT EFI_FILE_PROTOCOL   **NewHandle,
  IN  CHAR16              *FileName,
  IN  UINT64              OpenMode,
  IN  UINT64              Attributes
  )
{
  EMU_EFI_FILE_PRIVATE              *PrivateFile;

  //
  // Check for obvious invalid parameters.
  //
  if (This == NULL || NewHandle == NULL || FileName == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  switch (OpenMode) {
  case EFI_FILE_MODE_CREATE | EFI_FILE_MODE_READ | EFI_FILE_MODE_WRITE:
    if (Attributes &~EFI_FILE_VALID_ATTR) {
      return EFI_INVALID_PARAMETER;
    }

    if (Attributes & EFI_FILE_READ_ONLY) {
      return EFI_INVALID_PARAMETER;
    }

  //
  // fall through
  //
  case EFI_FILE_MODE_READ:
  case EFI_FILE_MODE_READ | EFI_FILE_MODE_WRITE:
    break;

  default:
    return EFI_INVALID_PARAMETER;
  }

  PrivateFile     = EMU_EFI_FILE_PRIVATE_DATA_FROM_THIS (This);

  return PrivateFile->Io->Open (PrivateFile->Io, NewHandle, FileName, OpenMode, Attributes);
}



/**
  Close the file handle

  @param  This          Protocol instance pointer.

  @retval EFI_SUCCESS   The file was closed.

**/
EFI_STATUS
EFIAPI
EmuSimpleFileSystemClose (
  IN EFI_FILE_PROTOCOL  *This
  )
{
  EFI_STATUS              Status;
  EMU_EFI_FILE_PRIVATE    *PrivateFile;
  EFI_TPL                 OldTpl;

  if (This == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  PrivateFile = EMU_EFI_FILE_PRIVATE_DATA_FROM_THIS (This);

  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);

  Status = PrivateFile->Io->Close (PrivateFile->Io);
  if (!EFI_ERROR (Status)) {
    gBS->FreePool (PrivateFile);
  }

  gBS->RestoreTPL (OldTpl);
  
  return Status;
}


/**
  Close and delete the file handle.

  @param  This                     Protocol instance pointer.
                                   
  @retval EFI_SUCCESS              The file was closed and deleted.
  @retval EFI_WARN_DELETE_FAILURE  The handle was closed but the file was not deleted.

**/
EFI_STATUS
EFIAPI
EmuSimpleFileSystemDelete (
  IN EFI_FILE_PROTOCOL  *This
  )
{
  EFI_STATUS              Status;
  EMU_EFI_FILE_PRIVATE    *PrivateFile;
  EFI_TPL                 OldTpl;

  if (This == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
  
  PrivateFile = EMU_EFI_FILE_PRIVATE_DATA_FROM_THIS (This);

  Status = PrivateFile->Io->Delete (PrivateFile->Io);
  if (!EFI_ERROR (Status)) {
    gBS->FreePool (PrivateFile);
  }

  gBS->RestoreTPL (OldTpl);

  return Status;
}


/**
  Read data from the file.

  @param  This       Protocol instance pointer.
  @param  BufferSize On input size of buffer, on output amount of data in buffer.
  @param  Buffer     The buffer in which data is read.

  @retval EFI_SUCCESS          Data was read.
  @retval EFI_NO_MEDIA         The device has no media.
  @retval EFI_DEVICE_ERROR     The device reported an error.
  @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
  @retval EFI_BUFFER_TO_SMALL  BufferSize is too small. BufferSize contains required size.

**/
EFI_STATUS
EFIAPI
EmuSimpleFileSystemRead (
  IN     EFI_FILE_PROTOCOL  *This,
  IN OUT UINTN              *BufferSize,
  OUT    VOID               *Buffer
  )
{
  EFI_STATUS              Status;
  EMU_EFI_FILE_PRIVATE    *PrivateFile;
  EFI_TPL                 OldTpl;

  if (This == NULL || BufferSize == NULL) {
    return EFI_INVALID_PARAMETER;
  }
  
  if ((*BufferSize != 0) && (Buffer == NULL)) {
    // Buffer can be NULL  if *BufferSize is zero
    return EFI_INVALID_PARAMETER;
  }

  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
  
  PrivateFile = EMU_EFI_FILE_PRIVATE_DATA_FROM_THIS (This);

  Status = PrivateFile->Io->Read (PrivateFile->Io, BufferSize, Buffer);

  gBS->RestoreTPL (OldTpl);
  return Status;
}


/**
  Write data to a file.

  @param  This       Protocol instance pointer.
  @param  BufferSize On input size of buffer, on output amount of data in buffer.
  @param  Buffer     The buffer in which data to write.

  @retval EFI_SUCCESS          Data was written.
  @retval EFI_UNSUPPORTED      Writes to Open directory are not supported.
  @retval EFI_NO_MEDIA         The device has no media.
  @retval EFI_DEVICE_ERROR     The device reported an error.
  @retval EFI_DEVICE_ERROR     An attempt was made to write to a deleted file.
  @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
  @retval EFI_WRITE_PROTECTED  The device is write protected.
  @retval EFI_ACCESS_DENIED    The file was open for read only.
  @retval EFI_VOLUME_FULL      The volume is full.

**/
EFI_STATUS
EFIAPI
EmuSimpleFileSystemWrite (
  IN     EFI_FILE_PROTOCOL  *This,
  IN OUT UINTN              *BufferSize,
  IN     VOID               *Buffer
  )
{
  EFI_STATUS            Status;
  EMU_EFI_FILE_PRIVATE *PrivateFile;
  EFI_TPL               OldTpl;

  if (This == NULL || BufferSize == NULL || Buffer == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);

  PrivateFile = EMU_EFI_FILE_PRIVATE_DATA_FROM_THIS (This);

  Status = PrivateFile->Io->Write (PrivateFile->Io, BufferSize, Buffer);

  gBS->RestoreTPL (OldTpl);
  return Status;
}


/**
  Set a files current position

  @param  This            Protocol instance pointer.
  @param  Position        Byte position from the start of the file.
                          
  @retval EFI_SUCCESS     Position was updated.
  @retval EFI_UNSUPPORTED Seek request for non-zero is not valid on open.

**/
EFI_STATUS
EFIAPI
EmuSimpleFileSystemGetPosition (
  IN  EFI_FILE_PROTOCOL   *This,
  OUT UINT64              *Position
  )
{
  EFI_STATUS            Status;
  EMU_EFI_FILE_PRIVATE *PrivateFile;
  EFI_TPL               OldTpl;

  if (This == NULL || Position == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
  
  PrivateFile   = EMU_EFI_FILE_PRIVATE_DATA_FROM_THIS (This);

  Status = PrivateFile->Io->GetPosition (PrivateFile->Io, Position);

  gBS->RestoreTPL (OldTpl);
  return Status;
}



/**
  Get a file's current position

  @param  This            Protocol instance pointer.
  @param  Position        Byte position from the start of the file.
                          
  @retval EFI_SUCCESS     Position was updated.
  @retval EFI_UNSUPPORTED Seek request for non-zero is not valid on open..

**/
EFI_STATUS
EFIAPI
EmuSimpleFileSystemSetPosition (
  IN EFI_FILE_PROTOCOL  *This,
  IN UINT64             Position
  )
{
  EFI_STATUS              Status;
  EMU_EFI_FILE_PRIVATE    *PrivateFile;
  EFI_TPL                 OldTpl;

  if (This == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
  
  PrivateFile = EMU_EFI_FILE_PRIVATE_DATA_FROM_THIS (This);

  Status = PrivateFile->Io->SetPosition (PrivateFile->Io, Position);

  gBS->RestoreTPL (OldTpl);
  return Status;
}


/**
  Get information about a file.

  @param  This            Protocol instance pointer.
  @param  InformationType Type of information to return in Buffer.
  @param  BufferSize      On input size of buffer, on output amount of data in buffer.
  @param  Buffer          The buffer to return data.

  @retval EFI_SUCCESS          Data was returned.
  @retval EFI_UNSUPPORTED      InformationType is not supported.
  @retval EFI_NO_MEDIA         The device has no media.
  @retval EFI_DEVICE_ERROR     The device reported an error.
  @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
  @retval EFI_WRITE_PROTECTED  The device is write protected.
  @retval EFI_ACCESS_DENIED    The file was open for read only.
  @retval EFI_BUFFER_TOO_SMALL Buffer was too small; required size returned in BufferSize.

**/
EFI_STATUS
EFIAPI
EmuSimpleFileSystemGetInfo (
  IN     EFI_FILE_PROTOCOL  *This,
  IN     EFI_GUID           *InformationType,
  IN OUT UINTN              *BufferSize,
  OUT    VOID               *Buffer
  )
{
  EFI_STATUS                        Status;
  EMU_EFI_FILE_PRIVATE              *PrivateFile;
  EFI_TPL                           OldTpl;

  if (This == NULL || InformationType == NULL || BufferSize == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
    
  PrivateFile = EMU_EFI_FILE_PRIVATE_DATA_FROM_THIS (This);

  Status = PrivateFile->Io->GetInfo (PrivateFile->Io, InformationType, BufferSize, Buffer);

  gBS->RestoreTPL (OldTpl);
  return Status;
}


/**
  Set information about a file

  @param  File            Protocol instance pointer.
  @param  InformationType Type of information in Buffer.
  @param  BufferSize      Size of buffer.
  @param  Buffer          The data to write.

  @retval EFI_SUCCESS          Data was set.
  @retval EFI_UNSUPPORTED      InformationType is not supported.
  @retval EFI_NO_MEDIA         The device has no media.
  @retval EFI_DEVICE_ERROR     The device reported an error.
  @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
  @retval EFI_WRITE_PROTECTED  The device is write protected.
  @retval EFI_ACCESS_DENIED    The file was open for read only.

**/
EFI_STATUS
EFIAPI
EmuSimpleFileSystemSetInfo (
  IN EFI_FILE_PROTOCOL*This,
  IN EFI_GUID         *InformationType,
  IN UINTN            BufferSize,
  IN VOID             *Buffer
  )
{
  EFI_STATUS                        Status;
  EMU_EFI_FILE_PRIVATE              *PrivateFile;
  EFI_TPL                           OldTpl;

  //
  // Check for invalid parameters.
  //
  if (This == NULL || InformationType == NULL || BufferSize == 0 || Buffer == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
  
  PrivateFile               = EMU_EFI_FILE_PRIVATE_DATA_FROM_THIS (This);

  Status = PrivateFile->Io->SetInfo (PrivateFile->Io, InformationType, BufferSize, Buffer);

  gBS->RestoreTPL (OldTpl);  
  return Status;
}


/**
  Flush data back for the file handle.

  @param  This Protocol instance pointer.

  @retval EFI_SUCCESS          Data was flushed.
  @retval EFI_UNSUPPORTED      Writes to Open directory are not supported.
  @retval EFI_NO_MEDIA         The device has no media.
  @retval EFI_DEVICE_ERROR     The device reported an error.
  @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
  @retval EFI_WRITE_PROTECTED  The device is write protected.
  @retval EFI_ACCESS_DENIED    The file was open for read only.
  @retval EFI_VOLUME_FULL      The volume is full.

**/
EFI_STATUS
EFIAPI
EmuSimpleFileSystemFlush (
  IN EFI_FILE_PROTOCOL  *This
  )
{
  EFI_STATUS                Status;
  EMU_EFI_FILE_PRIVATE      *PrivateFile;
  EFI_TPL                   OldTpl;

  if (This == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
  
  PrivateFile = EMU_EFI_FILE_PRIVATE_DATA_FROM_THIS (This);

  Status = PrivateFile->Io->Flush (PrivateFile->Io);

  gBS->RestoreTPL (OldTpl);
  return Status;
}



/**
  Open the root directory on a volume.

  @param  This Protocol instance pointer.
  @param  Root Returns an Open file handle for the root directory

  @retval EFI_SUCCESS          The device was opened.
  @retval EFI_UNSUPPORTED      This volume does not support the file system.
  @retval EFI_NO_MEDIA         The device has no media.
  @retval EFI_DEVICE_ERROR     The device reported an error.
  @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
  @retval EFI_ACCESS_DENIED    The service denied access to the file.
  @retval EFI_OUT_OF_RESOURCES The volume was not opened due to lack of resources.

**/
EFI_STATUS
EFIAPI
EmuSimpleFileSystemOpenVolume (
  IN EFI_SIMPLE_FILE_SYSTEM_PROTOCOL  *This,
  OUT EFI_FILE_PROTOCOL               **Root
  )
{
  EFI_STATUS                        Status;
  EMU_SIMPLE_FILE_SYSTEM_PRIVATE    *Private;
  EMU_EFI_FILE_PRIVATE              *PrivateFile;
  EFI_TPL                           OldTpl;

  if (This == NULL || Root == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);

  Private = EMU_SIMPLE_FILE_SYSTEM_PRIVATE_DATA_FROM_THIS (This);

  PrivateFile = AllocatePool (sizeof (EMU_EFI_FILE_PRIVATE));
  if (PrivateFile == NULL) {
    goto Done;
  }
  
  PrivateFile->Signature            = EMU_EFI_FILE_PRIVATE_SIGNATURE;
  PrivateFile->IoThunk              = Private->IoThunk;
  PrivateFile->SimpleFileSystem     = This;
  PrivateFile->EfiFile.Revision     = EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_REVISION;
  PrivateFile->EfiFile.Open         = EmuSimpleFileSystemOpen;
  PrivateFile->EfiFile.Close        = EmuSimpleFileSystemClose;
  PrivateFile->EfiFile.Delete       = EmuSimpleFileSystemDelete;
  PrivateFile->EfiFile.Read         = EmuSimpleFileSystemRead;
  PrivateFile->EfiFile.Write        = EmuSimpleFileSystemWrite;
  PrivateFile->EfiFile.GetPosition  = EmuSimpleFileSystemGetPosition;
  PrivateFile->EfiFile.SetPosition  = EmuSimpleFileSystemSetPosition;
  PrivateFile->EfiFile.GetInfo      = EmuSimpleFileSystemGetInfo;
  PrivateFile->EfiFile.SetInfo      = EmuSimpleFileSystemSetInfo;
  PrivateFile->EfiFile.Flush        = EmuSimpleFileSystemFlush;

  *Root = &PrivateFile->EfiFile;

  Status = Private->Io->OpenVolume (Private->Io, &PrivateFile->Io);
  if (EFI_ERROR (Status)) {
    goto Done;
  }
  
  AddUnicodeString2 (
    "eng",
    gEmuSimpleFileSystemComponentName.SupportedLanguages,
    &Private->ControllerNameTable,
    Private->IoThunk->ConfigString,
    TRUE
    );

  AddUnicodeString2 (
    "en",
    gEmuSimpleFileSystemComponentName.SupportedLanguages,
    &Private->ControllerNameTable,
    Private->IoThunk->ConfigString,
    FALSE
    );


Done:
  if (EFI_ERROR (Status)) {
    if (PrivateFile) {
      gBS->FreePool (PrivateFile);
    }
    
    *Root = NULL;
  }

  gBS->RestoreTPL (OldTpl);

  return Status;
}

/**
  Tests to see if this driver supports a given controller. If a child device is provided, 
  it further tests to see if this driver supports creating a handle for the specified child device.

  This function checks to see if the driver specified by This supports the device specified by 
  ControllerHandle. Drivers will typically use the device path attached to 
  ControllerHandle and/or the services from the bus I/O abstraction attached to 
  ControllerHandle to determine if the driver supports ControllerHandle. This function 
  may be called many times during platform initialization. In order to reduce boot times, the tests 
  performed by this function must be very small, and take as little time as possible to execute. This 
  function must not change the state of any hardware devices, and this function must be aware that the 
  device specified by ControllerHandle may already be managed by the same driver or a 
  different driver. This function must match its calls to AllocatePages() with FreePages(), 
  AllocatePool() with FreePool(), and OpenProtocol() with CloseProtocol().  
  Because ControllerHandle may have been previously started by the same driver, if a protocol is 
  already in the opened state, then it must not be closed with CloseProtocol(). This is required 
  to guarantee the state of ControllerHandle is not modified by this function.

  @param[in]  This                 A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
  @param[in]  ControllerHandle     The handle of the controller to test. This handle 
                                   must support a protocol interface that supplies 
                                   an I/O abstraction to the driver.
  @param[in]  RemainingDevicePath  A pointer to the remaining portion of a device path.  This 
                                   parameter is ignored by device drivers, and is optional for bus 
                                   drivers. For bus drivers, if this parameter is not NULL, then 
                                   the bus driver must determine if the bus controller specified 
                                   by ControllerHandle and the child controller specified 
                                   by RemainingDevicePath are both supported by this 
                                   bus driver.

  @retval EFI_SUCCESS              The device specified by ControllerHandle and
                                   RemainingDevicePath is supported by the driver specified by This.
  @retval EFI_ALREADY_STARTED      The device specified by ControllerHandle and
                                   RemainingDevicePath is already being managed by the driver
                                   specified by This.
  @retval EFI_ACCESS_DENIED        The device specified by ControllerHandle and
                                   RemainingDevicePath is already being managed by a different
                                   driver or an application that requires exclusive access.
                                   Currently not implemented.
  @retval EFI_UNSUPPORTED          The device specified by ControllerHandle and
                                   RemainingDevicePath is not supported by the driver specified by This.
**/
EFI_STATUS
EFIAPI
EmuSimpleFileSystemDriverBindingSupported (
  IN  EFI_DRIVER_BINDING_PROTOCOL  *This,
  IN  EFI_HANDLE                   ControllerHandle,
  IN  EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath
  )
{
  EFI_STATUS              Status;
  EMU_IO_THUNK_PROTOCOL  *EmuIoThunk;

  //
  // Open the IO Abstraction(s) needed to perform the supported test
  //
  Status = gBS->OpenProtocol (
                  ControllerHandle,
                  &gEmuIoThunkProtocolGuid,
                  (VOID **)&EmuIoThunk,
                  This->DriverBindingHandle,
                  ControllerHandle,
                  EFI_OPEN_PROTOCOL_BY_DRIVER
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Make sure GUID is for a File System handle.
  //
  Status = EFI_UNSUPPORTED;
  if (CompareGuid (EmuIoThunk->Protocol, &gEfiSimpleFileSystemProtocolGuid)) {
    Status = EFI_SUCCESS;
  }

  //
  // Close the I/O Abstraction(s) used to perform the supported test
  //
  gBS->CloseProtocol (
        ControllerHandle,
        &gEmuIoThunkProtocolGuid,
        This->DriverBindingHandle,
        ControllerHandle
        );

  return Status;
}



/**
  Starts a device controller or a bus controller.

  The Start() function is designed to be invoked from the EFI boot service ConnectController().
  As a result, much of the error checking on the parameters to Start() has been moved into this 
  common boot service. It is legal to call Start() from other locations, 
  but the following calling restrictions must be followed, or the system behavior will not be deterministic.
  1. ControllerHandle must be a valid EFI_HANDLE.
  2. If RemainingDevicePath is not NULL, then it must be a pointer to a naturally aligned
     EFI_DEVICE_PATH_PROTOCOL.
  3. Prior to calling Start(), the Supported() function for the driver specified by This must
     have been called with the same calling parameters, and Supported() must have returned EFI_SUCCESS.  

  @param[in]  This                 A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
  @param[in]  ControllerHandle     The handle of the controller to start. This handle 
                                   must support a protocol interface that supplies 
                                   an I/O abstraction to the driver.
  @param[in]  RemainingDevicePath  A pointer to the remaining portion of a device path.  This 
                                   parameter is ignored by device drivers, and is optional for bus 
                                   drivers. For a bus driver, if this parameter is NULL, then handles 
                                   for all the children of Controller are created by this driver.  
                                   If this parameter is not NULL and the first Device Path Node is 
                                   not the End of Device Path Node, then only the handle for the 
                                   child device specified by the first Device Path Node of 
                                   RemainingDevicePath is created by this driver.
                                   If the first Device Path Node of RemainingDevicePath is 
                                   the End of Device Path Node, no child handle is created by this
                                   driver.

  @retval EFI_SUCCESS              The device was started.
  @retval EFI_DEVICE_ERROR         The device could not be started due to a device error.Currently not implemented.
  @retval EFI_OUT_OF_RESOURCES     The request could not be completed due to a lack of resources.
  @retval Others                   The driver failded to start the device.

**/
EFI_STATUS
EFIAPI
EmuSimpleFileSystemDriverBindingStart (
  IN  EFI_DRIVER_BINDING_PROTOCOL   *This,
  IN  EFI_HANDLE                    ControllerHandle,
  IN  EFI_DEVICE_PATH_PROTOCOL      *RemainingDevicePath
  )
{
  EFI_STATUS                        Status;
  EMU_IO_THUNK_PROTOCOL             *EmuIoThunk;
  EMU_SIMPLE_FILE_SYSTEM_PRIVATE    *Private;

  Private = NULL;

  //
  // Open the IO Abstraction(s) needed
  //
  Status = gBS->OpenProtocol (
                  ControllerHandle,
                  &gEmuIoThunkProtocolGuid,
                  (VOID **)&EmuIoThunk,
                  This->DriverBindingHandle,
                  ControllerHandle,
                  EFI_OPEN_PROTOCOL_BY_DRIVER
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Validate GUID
  //
  if (!CompareGuid (EmuIoThunk->Protocol, &gEfiSimpleFileSystemProtocolGuid)) {
    Status = EFI_UNSUPPORTED;
    goto Done;
  }

  Private = AllocateZeroPool (sizeof (EMU_SIMPLE_FILE_SYSTEM_PRIVATE));
  if (Private == NULL) {
    goto Done;
  }

  Status = EmuIoThunk->Open (EmuIoThunk);
  if (EFI_ERROR (Status)) {
    goto Done;
  }

  Private->Signature = EMU_SIMPLE_FILE_SYSTEM_PRIVATE_SIGNATURE;
  Private->IoThunk   = EmuIoThunk;
  Private->Io        = EmuIoThunk->Interface;
  
  Private->SimpleFileSystem.Revision    = EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_REVISION;
  Private->SimpleFileSystem.OpenVolume  = EmuSimpleFileSystemOpenVolume;

  Private->ControllerNameTable = NULL;

  AddUnicodeString2 (
    "eng",
    gEmuSimpleFileSystemComponentName.SupportedLanguages,
    &Private->ControllerNameTable,
    EmuIoThunk->ConfigString,
    TRUE
    );
    
  AddUnicodeString2 (
    "en",
    gEmuSimpleFileSystemComponentName2.SupportedLanguages,
    &Private->ControllerNameTable,
    EmuIoThunk->ConfigString,
    FALSE
    );

  Status = gBS->InstallMultipleProtocolInterfaces (
                  &ControllerHandle,
                  &gEfiSimpleFileSystemProtocolGuid,  &Private->SimpleFileSystem,
                  NULL
                  );

Done:
  if (EFI_ERROR (Status)) {
    if (Private != NULL) {
      if (Private->ControllerNameTable != NULL) {
        FreeUnicodeStringTable (Private->ControllerNameTable);
      }
      
      gBS->FreePool (Private);
    
    }

    gBS->CloseProtocol (
          ControllerHandle,
          &gEmuIoThunkProtocolGuid,
          This->DriverBindingHandle,
          ControllerHandle
          );
  }

  return Status;
}


/**
  Stops a device controller or a bus controller.
  
  The Stop() function is designed to be invoked from the EFI boot service DisconnectController(). 
  As a result, much of the error checking on the parameters to Stop() has been moved 
  into this common boot service. It is legal to call Stop() from other locations, 
  but the following calling restrictions must be followed, or the system behavior will not be deterministic.
  1. ControllerHandle must be a valid EFI_HANDLE that was used on a previous call to this
     same driver's Start() function.
  2. The first NumberOfChildren handles of ChildHandleBuffer must all be a valid
     EFI_HANDLE. In addition, all of these handles must have been created in this driver's
     Start() function, and the Start() function must have called OpenProtocol() on
     ControllerHandle with an Attribute of EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER.
  
  @param[in]  This              A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
  @param[in]  ControllerHandle  A handle to the device being stopped. The handle must 
                                support a bus specific I/O protocol for the driver 
                                to use to stop the device.
  @param[in]  NumberOfChildren  The number of child device handles in ChildHandleBuffer.
  @param[in]  ChildHandleBuffer An array of child handles to be freed. May be NULL 
                                if NumberOfChildren is 0.

  @retval EFI_SUCCESS           The device was stopped.
  @retval EFI_DEVICE_ERROR      The device could not be stopped due to a device error.

**/
EFI_STATUS
EFIAPI
EmuSimpleFileSystemDriverBindingStop (
  IN  EFI_DRIVER_BINDING_PROTOCOL  *This,
  IN  EFI_HANDLE                   ControllerHandle,
  IN  UINTN                        NumberOfChildren,
  IN  EFI_HANDLE                   *ChildHandleBuffer
  )
{
  EFI_STATUS                        Status;
  EFI_SIMPLE_FILE_SYSTEM_PROTOCOL   *SimpleFileSystem;
  EMU_SIMPLE_FILE_SYSTEM_PRIVATE    *Private;

  //
  // Get our context back
  //
  Status = gBS->OpenProtocol (
                  ControllerHandle,
                  &gEfiSimpleFileSystemProtocolGuid,
                  (VOID **)&SimpleFileSystem,
                  This->DriverBindingHandle,
                  ControllerHandle,
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL
                  );
  if (EFI_ERROR (Status)) {
    return EFI_UNSUPPORTED;
  }

  Private = EMU_SIMPLE_FILE_SYSTEM_PRIVATE_DATA_FROM_THIS (SimpleFileSystem);
  Status = Private->IoThunk->Close (Private->IoThunk);

  //
  // Uninstall the Simple File System Protocol from ControllerHandle
  //
  Status = gBS->UninstallMultipleProtocolInterfaces (
                  ControllerHandle,
                  &gEfiSimpleFileSystemProtocolGuid,  &Private->SimpleFileSystem,
                  NULL
                  );
  if (!EFI_ERROR (Status)) {
    Status = gBS->CloseProtocol (
                    ControllerHandle,
                    &gEmuIoThunkProtocolGuid,
                    This->DriverBindingHandle,
                    ControllerHandle
                    );
  }

  if (!EFI_ERROR (Status)) {
    //
    // Free our instance data
    //
    FreeUnicodeStringTable (Private->ControllerNameTable);
    gBS->FreePool (Private);
  }

  return Status;
}


EFI_DRIVER_BINDING_PROTOCOL gEmuSimpleFileSystemDriverBinding = {
  EmuSimpleFileSystemDriverBindingSupported,
  EmuSimpleFileSystemDriverBindingStart,
  EmuSimpleFileSystemDriverBindingStop,
  0xa,
  NULL,
  NULL
};




/**
  The user Entry Point for module EmuSimpleFileSystem. The user code starts with this function.

  @param[in] ImageHandle    The firmware allocated handle for the EFI image.  
  @param[in] SystemTable    A pointer to the EFI System Table.
  
  @retval EFI_SUCCESS       The entry point is executed successfully.
  @retval other             Some error occurs when executing this entry point.

**/
EFI_STATUS
EFIAPI
InitializeEmuSimpleFileSystem(
  IN EFI_HANDLE           ImageHandle,
  IN EFI_SYSTEM_TABLE     *SystemTable
  )
{
  EFI_STATUS              Status;

  Status = EfiLibInstallDriverBindingComponentName2 (
             ImageHandle,
             SystemTable,
             &gEmuSimpleFileSystemDriverBinding,
             ImageHandle,
             &gEmuSimpleFileSystemComponentName,
             &gEmuSimpleFileSystemComponentName2
             );
  ASSERT_EFI_ERROR (Status);

  return Status;
}