summaryrefslogtreecommitdiff
path: root/MdeModulePkg/Universal/EbcDxe/EbcInt.c
blob: 764732c29f273b3cb7d3d067d71ca52ee9a05b33 (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
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
/** @file
  Top level module for the EBC virtual machine implementation.
  Provides auxiliary support routines for the VM. That is, routines
  that are not particularly related to VM execution of EBC instructions.

Copyright (c) 2006 - 2008, Intel Corporation. <BR>
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 "EbcInt.h"
#include "EbcExecute.h"

//
// We'll keep track of all thunks we create in a linked list. Each
// thunk is tied to an image handle, so we have a linked list of
// image handles, with each having a linked list of thunks allocated
// to that image handle.
//
typedef struct _EBC_THUNK_LIST {
  VOID                    *ThunkBuffer;
  struct _EBC_THUNK_LIST  *Next;
} EBC_THUNK_LIST;

typedef struct _EBC_IMAGE_LIST {
  struct _EBC_IMAGE_LIST  *Next;
  EFI_HANDLE              ImageHandle;
  EBC_THUNK_LIST          *ThunkList;
} EBC_IMAGE_LIST;

/**
  This routine is called by the core when an image is being unloaded from
  memory. Basically we now have the opportunity to do any necessary cleanup.
  Typically this will include freeing any memory allocated for thunk-creation.

  @param  This                  A pointer to the EFI_EBC_PROTOCOL instance.
  @param  ImageHandle           Handle of image for which the thunk is being
                                created.

  @retval EFI_INVALID_PARAMETER The ImageHandle passed in was not found in the
                                internal list of EBC image handles.
  @retval EFI_SUCCESS           The function completed successfully.

**/
EFI_STATUS
EFIAPI
EbcUnloadImage (
  IN EFI_EBC_PROTOCOL   *This,
  IN EFI_HANDLE         ImageHandle
  );

/**
  This is the top-level routine plugged into the EBC protocol. Since thunks
  are very processor-specific, from here we dispatch directly to the very
  processor-specific routine EbcCreateThunks().

  @param  This                  A pointer to the EFI_EBC_PROTOCOL instance.
  @param  ImageHandle           Handle of image for which the thunk is being
                                created. The EBC interpreter may use this to
                                keep track of any resource allocations
                                performed in loading and executing the image.
  @param  EbcEntryPoint         Address of the actual EBC entry point or
                                protocol service the thunk should call.
  @param  Thunk                 Returned pointer to a thunk created.

  @retval EFI_SUCCESS           The function completed successfully.
  @retval EFI_INVALID_PARAMETER Image entry point is not 2-byte aligned.
  @retval EFI_OUT_OF_RESOURCES  Memory could not be allocated for the thunk.

**/
EFI_STATUS
EFIAPI
EbcCreateThunk (
  IN EFI_EBC_PROTOCOL   *This,
  IN EFI_HANDLE         ImageHandle,
  IN VOID               *EbcEntryPoint,
  OUT VOID              **Thunk
  );

/**
  Called to get the version of the interpreter.

  @param  This                  A pointer to the EFI_EBC_PROTOCOL instance.
  @param  Version               Pointer to where to store the returned version
                                of the interpreter.

  @retval EFI_SUCCESS           The function completed successfully.
  @retval EFI_INVALID_PARAMETER Version pointer is NULL.

**/
EFI_STATUS
EFIAPI
EbcGetVersion (
  IN EFI_EBC_PROTOCOL   *This,
  IN OUT UINT64         *Version
  );

/**
  To install default Callback function for the VM interpreter.

  @param  This                  A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL
                                instance.

  @retval EFI_SUCCESS           The function completed successfully.
  @retval Others                Some error occurs when creating periodic event.

**/
EFI_STATUS
EFIAPI
InitializeEbcCallback (
  IN EFI_DEBUG_SUPPORT_PROTOCOL  *This
  );

/**
  The default Exception Callback for the VM interpreter.
  In this function, we report status code, and print debug information
  about EBC_CONTEXT, then dead loop.

  @param  InterruptType          Interrupt type.
  @param  SystemContext          EBC system context.

**/
VOID
EFIAPI
CommonEbcExceptionHandler (
  IN EFI_EXCEPTION_TYPE   InterruptType,
  IN EFI_SYSTEM_CONTEXT   SystemContext
  );

/**
  The periodic callback function for EBC VM interpreter, which is used
  to support the EFI debug support protocol.

  @param  Event                  The Periodic Callback Event.
  @param  Context                It should be the address of VM_CONTEXT pointer.

**/
VOID
EFIAPI
EbcPeriodicNotifyFunction (
  IN EFI_EVENT     Event,
  IN VOID          *Context
  );

/**
  The VM interpreter calls this function on a periodic basis to support
  the EFI debug support protocol.

  @param  VmPtr                  Pointer to a VM context for passing info to the
                                 debugger.

  @retval EFI_SUCCESS            The function completed successfully.

**/
EFI_STATUS
EFIAPI
EbcDebugPeriodic (
  IN VM_CONTEXT *VmPtr
  );

//
// These two functions and the  GUID are used to produce an EBC test protocol.
// This functionality is definitely not required for execution.
//
/**
  Produces an EBC VM test protocol that can be used for regression tests.

  @param  IHandle                Handle on which to install the protocol.

  @retval EFI_OUT_OF_RESOURCES   Memory allocation failed.
  @retval EFI_SUCCESS            The function completed successfully.

**/
EFI_STATUS
InitEbcVmTestProtocol (
  IN EFI_HANDLE     *IHandle
  );

/**
  Returns the EFI_UNSUPPORTED Status.

  @return EFI_UNSUPPORTED  This function always return EFI_UNSUPPORTED status.

**/
EFI_STATUS
EbcVmTestUnsupported (
  VOID
  );

/**
  Registers a callback function that the EBC interpreter calls to flush the
  processor instruction cache following creation of thunks.

  @param  This        A pointer to the EFI_EBC_PROTOCOL instance.
  @param  Flush       Pointer to a function of type EBC_ICACH_FLUSH.

  @retval EFI_SUCCESS The function completed successfully.

**/
EFI_STATUS
EFIAPI
EbcRegisterICacheFlush (
  IN EFI_EBC_PROTOCOL   *This,
  IN EBC_ICACHE_FLUSH   Flush
  );

/**
  This EBC debugger protocol service is called by the debug agent

  @param  This                  A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL
                                instance.
  @param  MaxProcessorIndex     Pointer to a caller-allocated UINTN in which the
                                maximum supported processor index is returned.

  @retval EFI_SUCCESS           The function completed successfully.

**/
EFI_STATUS
EFIAPI
EbcDebugGetMaximumProcessorIndex (
  IN EFI_DEBUG_SUPPORT_PROTOCOL          *This,
  OUT UINTN                              *MaxProcessorIndex
  );

/**
  This protocol service is called by the debug agent to register a function
  for us to call on a periodic basis.

  @param  This                  A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL
                                instance.
  @param  ProcessorIndex        Specifies which processor the callback function
                                applies to.
  @param  PeriodicCallback      A pointer to a function of type
                                PERIODIC_CALLBACK that is the main periodic
                                entry point of the debug agent. It receives as a
                                parameter a pointer to the full context of the
                                interrupted execution thread.

  @retval EFI_SUCCESS           The function completed successfully.
  @retval EFI_ALREADY_STARTED   Non-NULL PeriodicCallback parameter when a
                                callback function was previously registered.
  @retval EFI_INVALID_PARAMETER Null PeriodicCallback parameter when no
                                callback function was previously registered.

**/
EFI_STATUS
EFIAPI
EbcDebugRegisterPeriodicCallback (
  IN EFI_DEBUG_SUPPORT_PROTOCOL  *This,
  IN UINTN                       ProcessorIndex,
  IN EFI_PERIODIC_CALLBACK       PeriodicCallback
  );

/**
  This protocol service is called by the debug agent to register a function
  for us to call when we detect an exception.

  @param  This                  A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL
                                instance.
  @param  ProcessorIndex        Specifies which processor the callback function
                                applies to.
  @param  ExceptionCallback     A pointer to a function of type
                                EXCEPTION_CALLBACK that is called when the
                                processor exception specified by ExceptionType
                                occurs. Passing NULL unregisters any previously
                                registered function associated with
                                ExceptionType.
  @param  ExceptionType         Specifies which processor exception to hook.

  @retval EFI_SUCCESS           The function completed successfully.
  @retval EFI_ALREADY_STARTED   Non-NULL ExceptionCallback parameter when a
                                callback function was previously registered.
  @retval EFI_INVALID_PARAMETER ExceptionType parameter is negative or exceeds
                                MAX_EBC_EXCEPTION.
  @retval EFI_INVALID_PARAMETER Null ExceptionCallback parameter when no
                                callback function was previously registered.

**/
EFI_STATUS
EFIAPI
EbcDebugRegisterExceptionCallback (
  IN EFI_DEBUG_SUPPORT_PROTOCOL  *This,
  IN UINTN                       ProcessorIndex,
  IN EFI_EXCEPTION_CALLBACK      ExceptionCallback,
  IN EFI_EXCEPTION_TYPE          ExceptionType
  );

/**
  This EBC debugger protocol service is called by the debug agent.  Required
  for DebugSupport compliance but is only stubbed out for EBC.

  @param  This                  A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL
                                instance.
  @param  ProcessorIndex        Specifies which processor the callback function
                                applies to.
  @param  Start                 StartSpecifies the physical base of the memory
                                range to be invalidated.
  @param  Length                Specifies the minimum number of bytes in the
                                processor's instruction cache to invalidate.

  @retval EFI_SUCCESS           The function completed successfully.

**/
EFI_STATUS
EFIAPI
EbcDebugInvalidateInstructionCache (
  IN EFI_DEBUG_SUPPORT_PROTOCOL          *This,
  IN UINTN                               ProcessorIndex,
  IN VOID                                *Start,
  IN UINT64                              Length
  );

//
// We have one linked list of image handles for the whole world. Since
// there should only be one interpreter, make them global. They must
// also be global since the execution of an EBC image does not provide
// a This pointer.
//
EBC_IMAGE_LIST         *mEbcImageList = NULL;

//
// Callback function to flush the icache after thunk creation
//
EBC_ICACHE_FLUSH       mEbcICacheFlush;

//
// These get set via calls by the debug agent
//
EFI_PERIODIC_CALLBACK  mDebugPeriodicCallback = NULL;
EFI_EXCEPTION_CALLBACK mDebugExceptionCallback[MAX_EBC_EXCEPTION + 1] = {NULL};
EFI_GUID               mEfiEbcVmTestProtocolGuid = EFI_EBC_VM_TEST_PROTOCOL_GUID;

VOID                   *mStackBuffer[MAX_STACK_NUM];
EFI_HANDLE             mStackBufferIndex[MAX_STACK_NUM];
UINTN                  mStackNum = 0;

//
// Event for Periodic callback
//
EFI_EVENT              mEbcPeriodicEvent;
VM_CONTEXT             *mVmPtr = NULL;


/**
  Initializes the VM EFI interface.  Allocates memory for the VM interface
  and registers the VM protocol.

  @param  ImageHandle            EFI image handle.
  @param  SystemTable            Pointer to the EFI system table.

  @return Standard EFI status code.

**/
EFI_STATUS
EFIAPI
InitializeEbcDriver (
  IN EFI_HANDLE           ImageHandle,
  IN EFI_SYSTEM_TABLE     *SystemTable
  )
{
  EFI_EBC_PROTOCOL            *EbcProtocol;
  EFI_EBC_PROTOCOL            *OldEbcProtocol;
  EFI_STATUS                  Status;
  EFI_DEBUG_SUPPORT_PROTOCOL  *EbcDebugProtocol;
  EFI_HANDLE                  *HandleBuffer;
  UINTN                       NumHandles;
  UINTN                       Index;
  BOOLEAN                     Installed;

  EbcProtocol      = NULL;
  EbcDebugProtocol = NULL;

  //
  // Allocate memory for our protocol. Then fill in the blanks.
  //
  EbcProtocol = AllocatePool (sizeof (EFI_EBC_PROTOCOL));

  if (EbcProtocol == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  EbcProtocol->CreateThunk          = EbcCreateThunk;
  EbcProtocol->UnloadImage          = EbcUnloadImage;
  EbcProtocol->RegisterICacheFlush  = EbcRegisterICacheFlush;
  EbcProtocol->GetVersion           = EbcGetVersion;
  mEbcICacheFlush                   = NULL;

  //
  // Find any already-installed EBC protocols and uninstall them
  //
  Installed     = FALSE;
  HandleBuffer  = NULL;
  Status = gBS->LocateHandleBuffer (
                  ByProtocol,
                  &gEfiEbcProtocolGuid,
                  NULL,
                  &NumHandles,
                  &HandleBuffer
                  );
  if (Status == EFI_SUCCESS) {
    //
    // Loop through the handles
    //
    for (Index = 0; Index < NumHandles; Index++) {
      Status = gBS->HandleProtocol (
                      HandleBuffer[Index],
                      &gEfiEbcProtocolGuid,
                      (VOID **) &OldEbcProtocol
                      );
      if (Status == EFI_SUCCESS) {
        if (gBS->ReinstallProtocolInterface (
                  HandleBuffer[Index],
                  &gEfiEbcProtocolGuid,
                  OldEbcProtocol,
                  EbcProtocol
                  ) == EFI_SUCCESS) {
          Installed = TRUE;
        }
      }
    }
  }

  if (HandleBuffer != NULL) {
    FreePool (HandleBuffer);
    HandleBuffer = NULL;
  }
  //
  // Add the protocol so someone can locate us if we haven't already.
  //
  if (!Installed) {
    Status = gBS->InstallProtocolInterface (
                    &ImageHandle,
                    &gEfiEbcProtocolGuid,
                    EFI_NATIVE_INTERFACE,
                    EbcProtocol
                    );
    if (EFI_ERROR (Status)) {
      FreePool (EbcProtocol);
      return Status;
    }
  }

  Status = InitEBCStack();
  if (EFI_ERROR(Status)) {
    goto ErrorExit;
  }

  //
  // Allocate memory for our debug protocol. Then fill in the blanks.
  //
  EbcDebugProtocol = AllocatePool (sizeof (EFI_DEBUG_SUPPORT_PROTOCOL));

  if (EbcDebugProtocol == NULL) {
    goto ErrorExit;
  }

  EbcDebugProtocol->Isa                         = IsaEbc;
  EbcDebugProtocol->GetMaximumProcessorIndex    = EbcDebugGetMaximumProcessorIndex;
  EbcDebugProtocol->RegisterPeriodicCallback    = EbcDebugRegisterPeriodicCallback;
  EbcDebugProtocol->RegisterExceptionCallback   = EbcDebugRegisterExceptionCallback;
  EbcDebugProtocol->InvalidateInstructionCache  = EbcDebugInvalidateInstructionCache;

  //
  // Add the protocol so the debug agent can find us
  //
  Status = gBS->InstallProtocolInterface (
                  &ImageHandle,
                  &gEfiDebugSupportProtocolGuid,
                  EFI_NATIVE_INTERFACE,
                  EbcDebugProtocol
                  );
  //
  // This is recoverable, so free the memory and continue.
  //
  if (EFI_ERROR (Status)) {
    FreePool (EbcDebugProtocol);
    goto ErrorExit;
  }
  //
  // Install EbcDebugSupport Protocol Successfully
  // Now we need to initialize the Ebc default Callback
  //
  Status = InitializeEbcCallback (EbcDebugProtocol);

  //
  // Produce a VM test interface protocol. Not required for execution.
  //
  DEBUG_CODE_BEGIN ();
    InitEbcVmTestProtocol (&ImageHandle);
  DEBUG_CODE_END ();

  return EFI_SUCCESS;

ErrorExit:
  FreeEBCStack();
  HandleBuffer  = NULL;
  Status = gBS->LocateHandleBuffer (
                  ByProtocol,
                  &gEfiEbcProtocolGuid,
                  NULL,
                  &NumHandles,
                  &HandleBuffer
                  );
  if (Status == EFI_SUCCESS) {
    //
    // Loop through the handles
    //
    for (Index = 0; Index < NumHandles; Index++) {
      Status = gBS->HandleProtocol (
                      HandleBuffer[Index],
                      &gEfiEbcProtocolGuid,
                      (VOID **) &OldEbcProtocol
                      );
      if (Status == EFI_SUCCESS) {
        gBS->UninstallProtocolInterface (
               HandleBuffer[Index],
               &gEfiEbcProtocolGuid,
               OldEbcProtocol
               );
      }
    }
  }

  if (HandleBuffer != NULL) {
    FreePool (HandleBuffer);
    HandleBuffer = NULL;
  }

  FreePool (EbcProtocol);

  return Status;
}


/**
  This is the top-level routine plugged into the EBC protocol. Since thunks
  are very processor-specific, from here we dispatch directly to the very
  processor-specific routine EbcCreateThunks().

  @param  This                  A pointer to the EFI_EBC_PROTOCOL instance.
  @param  ImageHandle           Handle of image for which the thunk is being
                                created. The EBC interpreter may use this to
                                keep track of any resource allocations
                                performed in loading and executing the image.
  @param  EbcEntryPoint         Address of the actual EBC entry point or
                                protocol service the thunk should call.
  @param  Thunk                 Returned pointer to a thunk created.

  @retval EFI_SUCCESS           The function completed successfully.
  @retval EFI_INVALID_PARAMETER Image entry point is not 2-byte aligned.
  @retval EFI_OUT_OF_RESOURCES  Memory could not be allocated for the thunk.

**/
EFI_STATUS
EFIAPI
EbcCreateThunk (
  IN EFI_EBC_PROTOCOL   *This,
  IN EFI_HANDLE         ImageHandle,
  IN VOID               *EbcEntryPoint,
  OUT VOID              **Thunk
  )
{
  EFI_STATUS  Status;

  Status = EbcCreateThunks (
            ImageHandle,
            EbcEntryPoint,
            Thunk,
            FLAG_THUNK_ENTRY_POINT
            );
  return Status;
}


/**
  This EBC debugger protocol service is called by the debug agent

  @param  This                  A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL
                                instance.
  @param  MaxProcessorIndex     Pointer to a caller-allocated UINTN in which the
                                maximum supported processor index is returned.

  @retval EFI_SUCCESS           The function completed successfully.

**/
EFI_STATUS
EFIAPI
EbcDebugGetMaximumProcessorIndex (
  IN EFI_DEBUG_SUPPORT_PROTOCOL          *This,
  OUT UINTN                              *MaxProcessorIndex
  )
{
  *MaxProcessorIndex = 0;
  return EFI_SUCCESS;
}


/**
  This protocol service is called by the debug agent to register a function
  for us to call on a periodic basis.

  @param  This                  A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL
                                instance.
  @param  ProcessorIndex        Specifies which processor the callback function
                                applies to.
  @param  PeriodicCallback      A pointer to a function of type
                                PERIODIC_CALLBACK that is the main periodic
                                entry point of the debug agent. It receives as a
                                parameter a pointer to the full context of the
                                interrupted execution thread.

  @retval EFI_SUCCESS           The function completed successfully.
  @retval EFI_ALREADY_STARTED   Non-NULL PeriodicCallback parameter when a
                                callback function was previously registered.
  @retval EFI_INVALID_PARAMETER Null PeriodicCallback parameter when no
                                callback function was previously registered.

**/
EFI_STATUS
EFIAPI
EbcDebugRegisterPeriodicCallback (
  IN EFI_DEBUG_SUPPORT_PROTOCOL  *This,
  IN UINTN                       ProcessorIndex,
  IN EFI_PERIODIC_CALLBACK       PeriodicCallback
  )
{
  if ((mDebugPeriodicCallback == NULL) && (PeriodicCallback == NULL)) {
    return EFI_INVALID_PARAMETER;
  }
  if ((mDebugPeriodicCallback != NULL) && (PeriodicCallback != NULL)) {
    return EFI_ALREADY_STARTED;
  }

  mDebugPeriodicCallback = PeriodicCallback;
  return EFI_SUCCESS;
}


/**
  This protocol service is called by the debug agent to register a function
  for us to call when we detect an exception.

  @param  This                  A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL
                                instance.
  @param  ProcessorIndex        Specifies which processor the callback function
                                applies to.
  @param  ExceptionCallback     A pointer to a function of type
                                EXCEPTION_CALLBACK that is called when the
                                processor exception specified by ExceptionType
                                occurs. Passing NULL unregisters any previously
                                registered function associated with
                                ExceptionType.
  @param  ExceptionType         Specifies which processor exception to hook.

  @retval EFI_SUCCESS           The function completed successfully.
  @retval EFI_ALREADY_STARTED   Non-NULL ExceptionCallback parameter when a
                                callback function was previously registered.
  @retval EFI_INVALID_PARAMETER ExceptionType parameter is negative or exceeds
                                MAX_EBC_EXCEPTION.
  @retval EFI_INVALID_PARAMETER Null ExceptionCallback parameter when no
                                callback function was previously registered.

**/
EFI_STATUS
EFIAPI
EbcDebugRegisterExceptionCallback (
  IN EFI_DEBUG_SUPPORT_PROTOCOL  *This,
  IN UINTN                       ProcessorIndex,
  IN EFI_EXCEPTION_CALLBACK      ExceptionCallback,
  IN EFI_EXCEPTION_TYPE          ExceptionType
  )
{
  if ((ExceptionType < 0) || (ExceptionType > MAX_EBC_EXCEPTION)) {
    return EFI_INVALID_PARAMETER;
  }
  if ((mDebugExceptionCallback[ExceptionType] == NULL) && (ExceptionCallback == NULL)) {
    return EFI_INVALID_PARAMETER;
  }
  if ((mDebugExceptionCallback[ExceptionType] != NULL) && (ExceptionCallback != NULL)) {
    return EFI_ALREADY_STARTED;
  }
  mDebugExceptionCallback[ExceptionType] = ExceptionCallback;
  return EFI_SUCCESS;
}


/**
  This EBC debugger protocol service is called by the debug agent.  Required
  for DebugSupport compliance but is only stubbed out for EBC.

  @param  This                  A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL
                                instance.
  @param  ProcessorIndex        Specifies which processor the callback function
                                applies to.
  @param  Start                 StartSpecifies the physical base of the memory
                                range to be invalidated.
  @param  Length                Specifies the minimum number of bytes in the
                                processor's instruction cache to invalidate.

  @retval EFI_SUCCESS           The function completed successfully.

**/
EFI_STATUS
EFIAPI
EbcDebugInvalidateInstructionCache (
  IN EFI_DEBUG_SUPPORT_PROTOCOL          *This,
  IN UINTN                               ProcessorIndex,
  IN VOID                                *Start,
  IN UINT64                              Length
  )
{
  return EFI_SUCCESS;
}


/**
  The VM interpreter calls this function when an exception is detected.

  @param  ExceptionType          Specifies the processor exception detected.
  @param  ExceptionFlags         Specifies the exception context.
  @param  VmPtr                  Pointer to a VM context for passing info to the
                                 EFI debugger.

  @retval EFI_SUCCESS            This function completed successfully.

**/
EFI_STATUS
EbcDebugSignalException (
  IN EFI_EXCEPTION_TYPE                   ExceptionType,
  IN EXCEPTION_FLAGS                      ExceptionFlags,
  IN VM_CONTEXT                           *VmPtr
  )
{
  EFI_SYSTEM_CONTEXT_EBC  EbcContext;
  EFI_SYSTEM_CONTEXT      SystemContext;

  ASSERT ((ExceptionType >= 0) && (ExceptionType <= MAX_EBC_EXCEPTION));
  //
  // Save the exception in the context passed in
  //
  VmPtr->ExceptionFlags |= ExceptionFlags;
  VmPtr->LastException = ExceptionType;
  //
  // If it's a fatal exception, then flag it in the VM context in case an
  // attached debugger tries to return from it.
  //
  if ((ExceptionFlags & EXCEPTION_FLAG_FATAL) != 0) {
    VmPtr->StopFlags |= STOPFLAG_APP_DONE;
  }

  //
  // If someone's registered for exception callbacks, then call them.
  //
  // EBC driver will register default exception callback to report the
  // status code via the status code API
  //
  if (mDebugExceptionCallback[ExceptionType] != NULL) {

    //
    // Initialize the context structure
    //
    EbcContext.R0                   = VmPtr->R[0];
    EbcContext.R1                   = VmPtr->R[1];
    EbcContext.R2                   = VmPtr->R[2];
    EbcContext.R3                   = VmPtr->R[3];
    EbcContext.R4                   = VmPtr->R[4];
    EbcContext.R5                   = VmPtr->R[5];
    EbcContext.R6                   = VmPtr->R[6];
    EbcContext.R7                   = VmPtr->R[7];
    EbcContext.Ip                   = (UINT64)(UINTN)VmPtr->Ip;
    EbcContext.Flags                = VmPtr->Flags;
    EbcContext.ControlFlags         = 0;
    SystemContext.SystemContextEbc  = &EbcContext;

    mDebugExceptionCallback[ExceptionType] (ExceptionType, SystemContext);
    //
    // Restore the context structure and continue to execute
    //
    VmPtr->R[0]  = EbcContext.R0;
    VmPtr->R[1]  = EbcContext.R1;
    VmPtr->R[2]  = EbcContext.R2;
    VmPtr->R[3]  = EbcContext.R3;
    VmPtr->R[4]  = EbcContext.R4;
    VmPtr->R[5]  = EbcContext.R5;
    VmPtr->R[6]  = EbcContext.R6;
    VmPtr->R[7]  = EbcContext.R7;
    VmPtr->Ip    = (VMIP)(UINTN)EbcContext.Ip;
    VmPtr->Flags = EbcContext.Flags;
  }

  return EFI_SUCCESS;
}


/**
  To install default Callback function for the VM interpreter.

  @param  This                  A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL
                                instance.

  @retval EFI_SUCCESS           The function completed successfully.
  @retval Others                Some error occurs when creating periodic event.

**/
EFI_STATUS
EFIAPI
InitializeEbcCallback (
  IN EFI_DEBUG_SUPPORT_PROTOCOL  *This
  )
{
  INTN       Index;
  EFI_STATUS Status;

  //
  // For ExceptionCallback
  //
  for (Index = 0; Index <= MAX_EBC_EXCEPTION; Index++) {
    EbcDebugRegisterExceptionCallback (
      This,
      0,
      CommonEbcExceptionHandler,
      Index
      );
  }

  //
  // For PeriodicCallback
  //
  Status = gBS->CreateEvent (
                  EVT_TIMER | EVT_NOTIFY_SIGNAL,
                  TPL_NOTIFY,
                  EbcPeriodicNotifyFunction,
                  &mVmPtr,
                  &mEbcPeriodicEvent
                  );
  if (EFI_ERROR(Status)) {
    return Status;
  }

  Status = gBS->SetTimer (
                  mEbcPeriodicEvent,
                  TimerPeriodic,
                  EBC_VM_PERIODIC_CALLBACK_RATE
                  );
  if (EFI_ERROR(Status)) {
    return Status;
  }

  return EFI_SUCCESS;
}


/**
  The default Exception Callback for the VM interpreter.
  In this function, we report status code, and print debug information
  about EBC_CONTEXT, then dead loop.

  @param  InterruptType          Interrupt type.
  @param  SystemContext          EBC system context.

**/
VOID
EFIAPI
CommonEbcExceptionHandler (
  IN EFI_EXCEPTION_TYPE   InterruptType,
  IN EFI_SYSTEM_CONTEXT   SystemContext
  )
{
  //
  // We deadloop here to make it easy to debug this issue.
  //
  ASSERT (FALSE);

  return ;
}


/**
  The periodic callback function for EBC VM interpreter, which is used
  to support the EFI debug support protocol.

  @param  Event                  The Periodic Callback Event.
  @param  Context                It should be the address of VM_CONTEXT pointer.

**/
VOID
EFIAPI
EbcPeriodicNotifyFunction (
  IN EFI_EVENT     Event,
  IN VOID          *Context
  )
{
  VM_CONTEXT *VmPtr;

  VmPtr = *(VM_CONTEXT **)Context;

  if (VmPtr != NULL) {
    EbcDebugPeriodic (VmPtr);
  }

  return ;
}


/**
  The VM interpreter calls this function on a periodic basis to support
  the EFI debug support protocol.

  @param  VmPtr                  Pointer to a VM context for passing info to the
                                 debugger.

  @retval EFI_SUCCESS            The function completed successfully.

**/
EFI_STATUS
EFIAPI
EbcDebugPeriodic (
  IN VM_CONTEXT *VmPtr
  )
{
  EFI_SYSTEM_CONTEXT_EBC   EbcContext;
  EFI_SYSTEM_CONTEXT       SystemContext;

  //
  // If someone's registered for periodic callbacks, then call them.
  //
  if (mDebugPeriodicCallback != NULL) {

    //
    // Initialize the context structure
    //
    EbcContext.R0                   = VmPtr->R[0];
    EbcContext.R1                   = VmPtr->R[1];
    EbcContext.R2                   = VmPtr->R[2];
    EbcContext.R3                   = VmPtr->R[3];
    EbcContext.R4                   = VmPtr->R[4];
    EbcContext.R5                   = VmPtr->R[5];
    EbcContext.R6                   = VmPtr->R[6];
    EbcContext.R7                   = VmPtr->R[7];
    EbcContext.Ip                   = (UINT64)(UINTN)VmPtr->Ip;
    EbcContext.Flags                = VmPtr->Flags;
    EbcContext.ControlFlags         = 0;
    SystemContext.SystemContextEbc  = &EbcContext;

    mDebugPeriodicCallback (SystemContext);

    //
    // Restore the context structure and continue to execute
    //
    VmPtr->R[0]  = EbcContext.R0;
    VmPtr->R[1]  = EbcContext.R1;
    VmPtr->R[2]  = EbcContext.R2;
    VmPtr->R[3]  = EbcContext.R3;
    VmPtr->R[4]  = EbcContext.R4;
    VmPtr->R[5]  = EbcContext.R5;
    VmPtr->R[6]  = EbcContext.R6;
    VmPtr->R[7]  = EbcContext.R7;
    VmPtr->Ip    = (VMIP)(UINTN)EbcContext.Ip;
    VmPtr->Flags = EbcContext.Flags;
  }

  return EFI_SUCCESS;
}


/**
  This routine is called by the core when an image is being unloaded from
  memory. Basically we now have the opportunity to do any necessary cleanup.
  Typically this will include freeing any memory allocated for thunk-creation.

  @param  This                  A pointer to the EFI_EBC_PROTOCOL instance.
  @param  ImageHandle           Handle of image for which the thunk is being
                                created.

  @retval EFI_INVALID_PARAMETER The ImageHandle passed in was not found in the
                                internal list of EBC image handles.
  @retval EFI_SUCCESS           The function completed successfully.

**/
EFI_STATUS
EFIAPI
EbcUnloadImage (
  IN EFI_EBC_PROTOCOL   *This,
  IN EFI_HANDLE         ImageHandle
  )
{
  EBC_THUNK_LIST  *ThunkList;
  EBC_THUNK_LIST  *NextThunkList;
  EBC_IMAGE_LIST  *ImageList;
  EBC_IMAGE_LIST  *PrevImageList;
  //
  // First go through our list of known image handles and see if we've already
  // created an image list element for this image handle.
  //
  ReturnEBCStackByHandle(ImageHandle);
  PrevImageList = NULL;
  for (ImageList = mEbcImageList; ImageList != NULL; ImageList = ImageList->Next) {
    if (ImageList->ImageHandle == ImageHandle) {
      break;
    }
    //
    // Save the previous so we can connect the lists when we remove this one
    //
    PrevImageList = ImageList;
  }

  if (ImageList == NULL) {
    return EFI_INVALID_PARAMETER;
  }
  //
  // Free up all the thunk buffers and thunks list elements for this image
  // handle.
  //
  ThunkList = ImageList->ThunkList;
  while (ThunkList != NULL) {
    NextThunkList = ThunkList->Next;
    FreePool (ThunkList->ThunkBuffer);
    FreePool (ThunkList);
    ThunkList = NextThunkList;
  }
  //
  // Now remove this image list element from the chain
  //
  if (PrevImageList == NULL) {
    //
    // Remove from head
    //
    mEbcImageList = ImageList->Next;
  } else {
    PrevImageList->Next = ImageList->Next;
  }
  //
  // Now free up the image list element
  //
  FreePool (ImageList);
  return EFI_SUCCESS;
}


/**
  Add a thunk to our list of thunks for a given image handle.
  Also flush the instruction cache since we've written thunk code
  to memory that will be executed eventually.

  @param  ImageHandle            The image handle to which the thunk is tied.
  @param  ThunkBuffer            The buffer that has been created/allocated.
  @param  ThunkSize              The size of the thunk memory allocated.

  @retval EFI_OUT_OF_RESOURCES   Memory allocation failed.
  @retval EFI_SUCCESS            The function completed successfully.

**/
EFI_STATUS
EbcAddImageThunk (
  IN EFI_HANDLE      ImageHandle,
  IN VOID            *ThunkBuffer,
  IN UINT32          ThunkSize
  )
{
  EBC_THUNK_LIST  *ThunkList;
  EBC_IMAGE_LIST  *ImageList;
  EFI_STATUS      Status;

  //
  // It so far so good, then flush the instruction cache
  //
  if (mEbcICacheFlush != NULL) {
    Status = mEbcICacheFlush ((EFI_PHYSICAL_ADDRESS) (UINTN) ThunkBuffer, ThunkSize);
    if (EFI_ERROR (Status)) {
      return Status;
    }
  }
  //
  // Go through our list of known image handles and see if we've already
  // created a image list element for this image handle.
  //
  for (ImageList = mEbcImageList; ImageList != NULL; ImageList = ImageList->Next) {
    if (ImageList->ImageHandle == ImageHandle) {
      break;
    }
  }

  if (ImageList == NULL) {
    //
    // Allocate a new one
    //
    ImageList = AllocatePool (sizeof (EBC_IMAGE_LIST));

    if (ImageList == NULL) {
      return EFI_OUT_OF_RESOURCES;
    }

    ImageList->ThunkList    = NULL;
    ImageList->ImageHandle  = ImageHandle;
    ImageList->Next         = mEbcImageList;
    mEbcImageList           = ImageList;
  }
  //
  // Ok, now create a new thunk element to add to the list
  //
  ThunkList = AllocatePool (sizeof (EBC_THUNK_LIST));

  if (ThunkList == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }
  //
  // Add it to the head of the list
  //
  ThunkList->Next         = ImageList->ThunkList;
  ThunkList->ThunkBuffer  = ThunkBuffer;
  ImageList->ThunkList    = ThunkList;
  return EFI_SUCCESS;
}

/**
  Registers a callback function that the EBC interpreter calls to flush the
  processor instruction cache following creation of thunks.

  @param  This        A pointer to the EFI_EBC_PROTOCOL instance.
  @param  Flush       Pointer to a function of type EBC_ICACH_FLUSH.

  @retval EFI_SUCCESS The function completed successfully.

**/
EFI_STATUS
EFIAPI
EbcRegisterICacheFlush (
  IN EFI_EBC_PROTOCOL   *This,
  IN EBC_ICACHE_FLUSH   Flush
  )
{
  mEbcICacheFlush = Flush;
  return EFI_SUCCESS;
}

/**
  Called to get the version of the interpreter.

  @param  This                  A pointer to the EFI_EBC_PROTOCOL instance.
  @param  Version               Pointer to where to store the returned version
                                of the interpreter.

  @retval EFI_SUCCESS           The function completed successfully.
  @retval EFI_INVALID_PARAMETER Version pointer is NULL.

**/
EFI_STATUS
EFIAPI
EbcGetVersion (
  IN EFI_EBC_PROTOCOL   *This,
  IN OUT UINT64         *Version
  )
{
  if (Version == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  *Version = GetVmVersion ();
  return EFI_SUCCESS;
}

/**
  Returns the stack index and buffer assosicated with the Handle parameter.

  @param  Handle                The EFI handle as the index to the EBC stack.
  @param  StackBuffer           A pointer to hold the returned stack buffer.
  @param  BufferIndex           A pointer to hold the returned stack index.

  @retval EFI_OUT_OF_RESOURCES  The Handle parameter does not correspond to any
                                existing EBC stack.
  @retval EFI_SUCCESS           The stack index and buffer were found and
                                returned to the caller.

**/
EFI_STATUS
GetEBCStack(
  IN  EFI_HANDLE Handle,
  OUT VOID       **StackBuffer,
  OUT UINTN      *BufferIndex
  )
{
  UINTN   Index;
  EFI_TPL OldTpl;
  OldTpl = gBS->RaiseTPL(TPL_HIGH_LEVEL);
  for (Index = 0; Index < mStackNum; Index ++) {
    if (mStackBufferIndex[Index] == NULL) {
      mStackBufferIndex[Index] = Handle;
      break;
    }
  }
  gBS->RestoreTPL(OldTpl);
  if (Index == mStackNum) {
    return EFI_OUT_OF_RESOURCES;
  }
  *BufferIndex = Index;
  *StackBuffer = mStackBuffer[Index];
  return EFI_SUCCESS;
}

/**
  Returns from the EBC stack by stack Index.

  @param  Index        Specifies which EBC stack to return from.

  @retval EFI_SUCCESS  The function completed successfully.

**/
EFI_STATUS
ReturnEBCStack(
  IN UINTN Index
  )
{
  mStackBufferIndex[Index] = NULL;
  return EFI_SUCCESS;
}

/**
  Returns from the EBC stack associated with the Handle parameter.

  @param  Handle      Specifies the EFI handle to find the EBC stack with.

  @retval EFI_SUCCESS The function completed successfully.

**/
EFI_STATUS
ReturnEBCStackByHandle(
  IN EFI_HANDLE Handle
  )
{
  UINTN Index;
  for (Index = 0; Index < mStackNum; Index ++) {
    if (mStackBufferIndex[Index] == Handle) {
      break;
    }
  }
  if (Index == mStackNum) {
    return EFI_NOT_FOUND;
  }
  mStackBufferIndex[Index] = NULL;
  return EFI_SUCCESS;
}

/**
  Allocates memory to hold all the EBC stacks.

  @retval EFI_SUCCESS          The EBC stacks were allocated successfully.
  @retval EFI_OUT_OF_RESOURCES Not enough memory available for EBC stacks.

**/
EFI_STATUS
InitEBCStack (
  VOID
  )
{
  for (mStackNum = 0; mStackNum < MAX_STACK_NUM; mStackNum ++) {
    mStackBuffer[mStackNum] = AllocatePool(STACK_POOL_SIZE);
    mStackBufferIndex[mStackNum] = NULL;
    if (mStackBuffer[mStackNum] == NULL) {
      break;
    }
  }
  if (mStackNum == 0) {
    return EFI_OUT_OF_RESOURCES;
  }
  return EFI_SUCCESS;
}


/**
  Free all EBC stacks allocated before.

  @retval EFI_SUCCESS   All the EBC stacks were freed.

**/
EFI_STATUS
FreeEBCStack(
  VOID
  )
{
  UINTN Index;
  for (Index = 0; Index < mStackNum; Index ++) {
    FreePool(mStackBuffer[Index]);
  }
  return EFI_SUCCESS;
}

/**
  Produces an EBC VM test protocol that can be used for regression tests.

  @param  IHandle                Handle on which to install the protocol.

  @retval EFI_OUT_OF_RESOURCES   Memory allocation failed.
  @retval EFI_SUCCESS            The function completed successfully.

**/
EFI_STATUS
InitEbcVmTestProtocol (
  IN EFI_HANDLE     *IHandle
  )
{
  EFI_HANDLE Handle;
  EFI_STATUS Status;
  EFI_EBC_VM_TEST_PROTOCOL *EbcVmTestProtocol;

  //
  // Allocate memory for the protocol, then fill in the fields
  //
  EbcVmTestProtocol = AllocatePool (sizeof (EFI_EBC_VM_TEST_PROTOCOL));
  if (EbcVmTestProtocol == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }
  EbcVmTestProtocol->Execute      = (EBC_VM_TEST_EXECUTE) EbcExecuteInstructions;

  DEBUG_CODE_BEGIN ();
    EbcVmTestProtocol->Assemble     = (EBC_VM_TEST_ASM) EbcVmTestUnsupported;
    EbcVmTestProtocol->Disassemble  = (EBC_VM_TEST_DASM) EbcVmTestUnsupported;
  DEBUG_CODE_END ();

  //
  // Publish the protocol
  //
  Handle  = NULL;
  Status  = gBS->InstallProtocolInterface (&Handle, &mEfiEbcVmTestProtocolGuid, EFI_NATIVE_INTERFACE, EbcVmTestProtocol);
  if (EFI_ERROR (Status)) {
    FreePool (EbcVmTestProtocol);
  }
  return Status;
}


/**
  Returns the EFI_UNSUPPORTED Status.

  @return EFI_UNSUPPORTED  This function always return EFI_UNSUPPORTED status.

**/
EFI_STATUS
EbcVmTestUnsupported (
  VOID
  )
{
  return EFI_UNSUPPORTED;
}