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
|
/** @file
Implement ReadOnly Variable Services required by PEIM and install
PEI ReadOnly Varaiable2 PPI. These services operates the non volatile storage space.
Copyright (c) 2006 - 2013, 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.
Module Name:
**/
#include "Variable.h"
//
// Module globals
//
EFI_PEI_READ_ONLY_VARIABLE2_PPI mVariablePpi = {
PeiGetVariable,
PeiGetNextVariableName
};
EFI_PEI_PPI_DESCRIPTOR mPpiListVariable = {
(EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
&gEfiPeiReadOnlyVariable2PpiGuid,
&mVariablePpi
};
/**
Provide the functionality of the variable services.
@param FileHandle Handle of the file being invoked.
Type EFI_PEI_FILE_HANDLE is defined in FfsFindNextFile().
@param PeiServices General purpose services available to every PEIM.
@retval EFI_SUCCESS If the interface could be successfully installed
@retval Others Returned from PeiServicesInstallPpi()
**/
EFI_STATUS
EFIAPI
PeimInitializeVariableServices (
IN EFI_PEI_FILE_HANDLE FileHandle,
IN CONST EFI_PEI_SERVICES **PeiServices
)
{
return PeiServicesInstallPpi (&mPpiListVariable);
}
/**
Gets the pointer to the first variable header in given variable store area.
@param VarStoreHeader Pointer to the Variable Store Header.
@return Pointer to the first variable header
**/
VARIABLE_HEADER *
GetStartPointer (
IN VARIABLE_STORE_HEADER *VarStoreHeader
)
{
//
// The end of variable store
//
return (VARIABLE_HEADER *) HEADER_ALIGN (VarStoreHeader + 1);
}
/**
This code gets the pointer to the last variable memory pointer byte.
@param VarStoreHeader Pointer to the Variable Store Header.
@return VARIABLE_HEADER* pointer to last unavailable Variable Header.
**/
VARIABLE_HEADER *
GetEndPointer (
IN VARIABLE_STORE_HEADER *VarStoreHeader
)
{
//
// The end of variable store
//
return (VARIABLE_HEADER *) HEADER_ALIGN ((UINTN) VarStoreHeader + VarStoreHeader->Size);
}
/**
This code checks if variable header is valid or not.
@param Variable Pointer to the Variable Header.
@retval TRUE Variable header is valid.
@retval FALSE Variable header is not valid.
**/
BOOLEAN
IsValidVariableHeader (
IN VARIABLE_HEADER *Variable
)
{
if (Variable == NULL || Variable->StartId != VARIABLE_DATA ) {
return FALSE;
}
return TRUE;
}
/**
This code gets the size of name of variable.
@param Variable Pointer to the Variable Header.
@return Size of variable in bytes in type UINTN.
**/
UINTN
NameSizeOfVariable (
IN VARIABLE_HEADER *Variable
)
{
if (Variable->State == (UINT8) (-1) ||
Variable->DataSize == (UINT32) (-1) ||
Variable->NameSize == (UINT32) (-1) ||
Variable->Attributes == (UINT32) (-1)) {
return 0;
}
return (UINTN) Variable->NameSize;
}
/**
This code gets the size of data of variable.
@param Variable Pointer to the Variable Header.
@return Size of variable in bytes in type UINTN.
**/
UINTN
DataSizeOfVariable (
IN VARIABLE_HEADER *Variable
)
{
if (Variable->State == (UINT8) (-1) ||
Variable->DataSize == (UINT32) (-1) ||
Variable->NameSize == (UINT32) (-1) ||
Variable->Attributes == (UINT32) (-1)) {
return 0;
}
return (UINTN) Variable->DataSize;
}
/**
This code gets the pointer to the variable name.
@param Variable Pointer to the Variable Header.
@return A CHAR16* pointer to Variable Name.
**/
CHAR16 *
GetVariableNamePtr (
IN VARIABLE_HEADER *Variable
)
{
return (CHAR16 *) (Variable + 1);
}
/**
This code gets the pointer to the variable data.
@param Variable Pointer to the Variable Header.
@return A UINT8* pointer to Variable Data.
**/
UINT8 *
GetVariableDataPtr (
IN VARIABLE_HEADER *Variable
)
{
UINTN Value;
//
// Be careful about pad size for alignment
//
Value = (UINTN) GetVariableNamePtr (Variable);
Value += NameSizeOfVariable (Variable);
Value += GET_PAD_SIZE (NameSizeOfVariable (Variable));
return (UINT8 *) Value;
}
/**
This code gets the pointer to the next variable header.
@param Variable Pointer to the Variable Header.
@return A VARIABLE_HEADER* pointer to next variable header.
**/
VARIABLE_HEADER *
GetNextVariablePtr (
IN VARIABLE_HEADER *Variable
)
{
UINTN Value;
if (!IsValidVariableHeader (Variable)) {
return NULL;
}
Value = (UINTN) GetVariableDataPtr (Variable);
Value += DataSizeOfVariable (Variable);
Value += GET_PAD_SIZE (DataSizeOfVariable (Variable));
//
// Be careful about pad size for alignment
//
return (VARIABLE_HEADER *) HEADER_ALIGN (Value);
}
/**
This code gets the pointer to the variable name.
@param VarStoreHeader Pointer to the Variable Store Header.
@retval EfiRaw Variable store is raw
@retval EfiValid Variable store is valid
@retval EfiInvalid Variable store is invalid
**/
VARIABLE_STORE_STATUS
GetVariableStoreStatus (
IN VARIABLE_STORE_HEADER *VarStoreHeader
)
{
if (CompareGuid (&VarStoreHeader->Signature, &gEfiVariableGuid) &&
VarStoreHeader->Format == VARIABLE_STORE_FORMATTED &&
VarStoreHeader->State == VARIABLE_STORE_HEALTHY
) {
return EfiValid;
}
if (((UINT32 *)(&VarStoreHeader->Signature))[0] == 0xffffffff &&
((UINT32 *)(&VarStoreHeader->Signature))[1] == 0xffffffff &&
((UINT32 *)(&VarStoreHeader->Signature))[2] == 0xffffffff &&
((UINT32 *)(&VarStoreHeader->Signature))[3] == 0xffffffff &&
VarStoreHeader->Size == 0xffffffff &&
VarStoreHeader->Format == 0xff &&
VarStoreHeader->State == 0xff
) {
return EfiRaw;
} else {
return EfiInvalid;
}
}
/**
This function compares a variable with variable entries in database.
@param Variable Pointer to the variable in our database
@param VariableName Name of the variable to compare to 'Variable'
@param VendorGuid GUID of the variable to compare to 'Variable'
@param PtrTrack Variable Track Pointer structure that contains Variable Information.
@retval EFI_SUCCESS Found match variable
@retval EFI_NOT_FOUND Variable not found
**/
EFI_STATUS
CompareWithValidVariable (
IN VARIABLE_HEADER *Variable,
IN CONST CHAR16 *VariableName,
IN CONST EFI_GUID *VendorGuid,
OUT VARIABLE_POINTER_TRACK *PtrTrack
)
{
VOID *Point;
if (VariableName[0] == 0) {
PtrTrack->CurrPtr = Variable;
return EFI_SUCCESS;
} else {
//
// Don't use CompareGuid function here for performance reasons.
// Instead we compare the GUID a UINT32 at a time and branch
// on the first failed comparison.
//
if ((((INT32 *) VendorGuid)[0] == ((INT32 *) &Variable->VendorGuid)[0]) &&
(((INT32 *) VendorGuid)[1] == ((INT32 *) &Variable->VendorGuid)[1]) &&
(((INT32 *) VendorGuid)[2] == ((INT32 *) &Variable->VendorGuid)[2]) &&
(((INT32 *) VendorGuid)[3] == ((INT32 *) &Variable->VendorGuid)[3])
) {
ASSERT (NameSizeOfVariable (Variable) != 0);
Point = (VOID *) GetVariableNamePtr (Variable);
if (CompareMem (VariableName, Point, NameSizeOfVariable (Variable)) == 0) {
PtrTrack->CurrPtr = Variable;
return EFI_SUCCESS;
}
}
}
return EFI_NOT_FOUND;
}
/**
Return the variable store header and the index table based on the Index.
@param Type The type of the variable store.
@param IndexTable Return the index table.
@return Pointer to the variable store header.
**/
VARIABLE_STORE_HEADER *
GetVariableStore (
IN VARIABLE_STORE_TYPE Type,
OUT VARIABLE_INDEX_TABLE **IndexTable OPTIONAL
)
{
EFI_HOB_GUID_TYPE *GuidHob;
EFI_FIRMWARE_VOLUME_HEADER *FvHeader;
VARIABLE_STORE_HEADER *VariableStoreHeader;
if (IndexTable != NULL) {
*IndexTable = NULL;
}
VariableStoreHeader = NULL;
switch (Type) {
case VariableStoreTypeHob:
GuidHob = GetFirstGuidHob (&gEfiVariableGuid);
if (GuidHob != NULL) {
VariableStoreHeader = (VARIABLE_STORE_HEADER *) GET_GUID_HOB_DATA (GuidHob);
}
break;
case VariableStoreTypeNv:
if (GetBootModeHob () != BOOT_IN_RECOVERY_MODE) {
//
// The content of NV storage for variable is not reliable in recovery boot mode.
//
FvHeader = (EFI_FIRMWARE_VOLUME_HEADER *) (UINTN) (PcdGet64 (PcdFlashNvStorageVariableBase64) != 0 ?
PcdGet64 (PcdFlashNvStorageVariableBase64) :
PcdGet32 (PcdFlashNvStorageVariableBase)
);
//
// Check if the Firmware Volume is not corrupted
//
if ((FvHeader->Signature != EFI_FVH_SIGNATURE) || (!CompareGuid (&gEfiSystemNvDataFvGuid, &FvHeader->FileSystemGuid))) {
DEBUG ((EFI_D_ERROR, "Firmware Volume for Variable Store is corrupted\n"));
break;
}
VariableStoreHeader = (VARIABLE_STORE_HEADER *) ((UINT8 *) FvHeader + FvHeader->HeaderLength);
if (IndexTable != NULL) {
GuidHob = GetFirstGuidHob (&gEfiVariableIndexTableGuid);
if (GuidHob != NULL) {
*IndexTable = GET_GUID_HOB_DATA (GuidHob);
} else {
//
// If it's the first time to access variable region in flash, create a guid hob to record
// VAR_ADDED type variable info.
// Note that as the resource of PEI phase is limited, only store the limited number of
// VAR_ADDED type variables to reduce access time.
//
*IndexTable = BuildGuidHob (&gEfiVariableIndexTableGuid, sizeof (VARIABLE_INDEX_TABLE));
(*IndexTable)->Length = 0;
(*IndexTable)->StartPtr = GetStartPointer (VariableStoreHeader);
(*IndexTable)->EndPtr = GetEndPointer (VariableStoreHeader);
(*IndexTable)->GoneThrough = 0;
}
}
}
break;
default:
ASSERT (FALSE);
break;
}
return VariableStoreHeader;
}
/**
Find the variable in the specified variable store.
@param VariableStoreHeader Pointer to the variable store header.
@param IndexTable Pointer to the index table.
@param VariableName Name of the variable to be found
@param VendorGuid Vendor GUID to be found.
@param PtrTrack Variable Track Pointer structure that contains Variable Information.
@retval EFI_SUCCESS Variable found successfully
@retval EFI_NOT_FOUND Variable not found
@retval EFI_INVALID_PARAMETER Invalid variable name
**/
EFI_STATUS
FindVariableEx (
IN VARIABLE_STORE_HEADER *VariableStoreHeader,
IN VARIABLE_INDEX_TABLE *IndexTable,
IN CONST CHAR16 *VariableName,
IN CONST EFI_GUID *VendorGuid,
OUT VARIABLE_POINTER_TRACK *PtrTrack
)
{
VARIABLE_HEADER *Variable;
VARIABLE_HEADER *LastVariable;
VARIABLE_HEADER *MaxIndex;
UINTN Index;
UINTN Offset;
BOOLEAN StopRecord;
VARIABLE_HEADER *InDeletedVariable;
if (VariableStoreHeader == NULL) {
return EFI_INVALID_PARAMETER;
}
if (GetVariableStoreStatus (VariableStoreHeader) != EfiValid) {
return EFI_UNSUPPORTED;
}
if (~VariableStoreHeader->Size == 0) {
return EFI_NOT_FOUND;
}
PtrTrack->StartPtr = GetStartPointer (VariableStoreHeader);
PtrTrack->EndPtr = GetEndPointer (VariableStoreHeader);
InDeletedVariable = NULL;
//
// No Variable Address equals zero, so 0 as initial value is safe.
//
MaxIndex = NULL;
if (IndexTable != NULL) {
//
// traverse the variable index table to look for varible.
// The IndexTable->Index[Index] records the distance of two neighbouring VAR_ADDED type variables.
//
for (Offset = 0, Index = 0; Index < IndexTable->Length; Index++) {
ASSERT (Index < sizeof (IndexTable->Index) / sizeof (IndexTable->Index[0]));
Offset += IndexTable->Index[Index];
MaxIndex = (VARIABLE_HEADER *) ((UINT8 *) IndexTable->StartPtr + Offset);
if (CompareWithValidVariable (MaxIndex, VariableName, VendorGuid, PtrTrack) == EFI_SUCCESS) {
if (PtrTrack->CurrPtr->State == (VAR_IN_DELETED_TRANSITION & VAR_ADDED)) {
InDeletedVariable = PtrTrack->CurrPtr;
} else {
return EFI_SUCCESS;
}
}
}
if (IndexTable->GoneThrough != 0) {
//
// If the table has all the existing variables indexed, return.
//
PtrTrack->CurrPtr = InDeletedVariable;
return (PtrTrack->CurrPtr == NULL) ? EFI_NOT_FOUND : EFI_SUCCESS;
}
}
if (MaxIndex != NULL) {
//
// HOB exists but the variable cannot be found in HOB
// If not found in HOB, then let's start from the MaxIndex we've found.
//
Variable = GetNextVariablePtr (MaxIndex);
LastVariable = MaxIndex;
} else {
//
// Start Pointers for the variable.
// Actual Data Pointer where data can be written.
//
Variable = PtrTrack->StartPtr;
LastVariable = PtrTrack->StartPtr;
}
//
// Find the variable by walk through variable store
//
StopRecord = FALSE;
while ((Variable < PtrTrack->EndPtr) && IsValidVariableHeader (Variable)) {
if (Variable->State == VAR_ADDED || Variable->State == (VAR_IN_DELETED_TRANSITION & VAR_ADDED)) {
//
// Record Variable in VariableIndex HOB
//
if ((IndexTable != NULL) && !StopRecord) {
Offset = (UINTN) Variable - (UINTN) LastVariable;
if ((Offset > 0x0FFFF) || (IndexTable->Length == sizeof (IndexTable->Index) / sizeof (IndexTable->Index[0]))) {
//
// Stop to record if the distance of two neighbouring VAR_ADDED variable is larger than the allowable scope(UINT16),
// or the record buffer is full.
//
StopRecord = TRUE;
} else {
IndexTable->Index[IndexTable->Length++] = (UINT16) Offset;
LastVariable = Variable;
}
}
if (CompareWithValidVariable (Variable, VariableName, VendorGuid, PtrTrack) == EFI_SUCCESS) {
if (PtrTrack->CurrPtr->State == (VAR_IN_DELETED_TRANSITION & VAR_ADDED)) {
InDeletedVariable = PtrTrack->CurrPtr;
} else {
return EFI_SUCCESS;
}
}
}
Variable = GetNextVariablePtr (Variable);
}
//
// If gone through the VariableStore, that means we never find in Firmware any more.
//
if ((IndexTable != NULL) && !StopRecord) {
IndexTable->GoneThrough = 1;
}
PtrTrack->CurrPtr = InDeletedVariable;
return (PtrTrack->CurrPtr == NULL) ? EFI_NOT_FOUND : EFI_SUCCESS;
}
/**
Find the variable in HOB and Non-Volatile variable storages.
@param VariableName Name of the variable to be found
@param VendorGuid Vendor GUID to be found.
@param PtrTrack Variable Track Pointer structure that contains Variable Information.
@retval EFI_SUCCESS Variable found successfully
@retval EFI_NOT_FOUND Variable not found
@retval EFI_INVALID_PARAMETER Invalid variable name
**/
EFI_STATUS
FindVariable (
IN CONST CHAR16 *VariableName,
IN CONST EFI_GUID *VendorGuid,
OUT VARIABLE_POINTER_TRACK *PtrTrack
)
{
EFI_STATUS Status;
VARIABLE_STORE_HEADER *VariableStoreHeader;
VARIABLE_INDEX_TABLE *IndexTable;
VARIABLE_STORE_TYPE Type;
if (VariableName[0] != 0 && VendorGuid == NULL) {
return EFI_INVALID_PARAMETER;
}
for (Type = (VARIABLE_STORE_TYPE) 0; Type < VariableStoreTypeMax; Type++) {
VariableStoreHeader = GetVariableStore (Type, &IndexTable);
Status = FindVariableEx (
VariableStoreHeader,
IndexTable,
VariableName,
VendorGuid,
PtrTrack
);
if (!EFI_ERROR (Status)) {
return Status;
}
}
return EFI_NOT_FOUND;
}
/**
This service retrieves a variable's value using its name and GUID.
Read the specified variable from the UEFI variable store. If the Data
buffer is too small to hold the contents of the variable, the error
EFI_BUFFER_TOO_SMALL is returned and DataSize is set to the required buffer
size to obtain the data.
@param This A pointer to this instance of the EFI_PEI_READ_ONLY_VARIABLE2_PPI.
@param VariableName A pointer to a null-terminated string that is the variable's name.
@param VariableGuid A pointer to an EFI_GUID that is the variable's GUID. The combination of
VariableGuid and VariableName must be unique.
@param Attributes If non-NULL, on return, points to the variable's attributes.
@param DataSize On entry, points to the size in bytes of the Data buffer.
On return, points to the size of the data returned in Data.
@param Data Points to the buffer which will hold the returned variable value.
@retval EFI_SUCCESS The variable was read successfully.
@retval EFI_NOT_FOUND The variable could not be found.
@retval EFI_BUFFER_TOO_SMALL The DataSize is too small for the resulting data.
DataSize is updated with the size required for
the specified variable.
@retval EFI_INVALID_PARAMETER VariableName, VariableGuid, DataSize or Data is NULL.
@retval EFI_DEVICE_ERROR The variable could not be retrieved because of a device error.
**/
EFI_STATUS
EFIAPI
PeiGetVariable (
IN CONST EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,
IN CONST CHAR16 *VariableName,
IN CONST EFI_GUID *VariableGuid,
OUT UINT32 *Attributes,
IN OUT UINTN *DataSize,
OUT VOID *Data
)
{
VARIABLE_POINTER_TRACK Variable;
UINTN VarDataSize;
EFI_STATUS Status;
if (VariableName == NULL || VariableGuid == NULL || DataSize == NULL) {
return EFI_INVALID_PARAMETER;
}
//
// Find existing variable
//
Status = FindVariable (VariableName, VariableGuid, &Variable);
if (EFI_ERROR (Status)) {
return Status;
}
//
// Get data size
//
VarDataSize = DataSizeOfVariable (Variable.CurrPtr);
if (*DataSize >= VarDataSize) {
if (Data == NULL) {
return EFI_INVALID_PARAMETER;
}
CopyMem (Data, GetVariableDataPtr (Variable.CurrPtr), VarDataSize);
if (Attributes != NULL) {
*Attributes = Variable.CurrPtr->Attributes;
}
*DataSize = VarDataSize;
return EFI_SUCCESS;
} else {
*DataSize = VarDataSize;
return EFI_BUFFER_TOO_SMALL;
}
}
/**
Return the next variable name and GUID.
This function is called multiple times to retrieve the VariableName
and VariableGuid of all variables currently available in the system.
On each call, the previous results are passed into the interface,
and, on return, the interface returns the data for the next
interface. When the entire variable list has been returned,
EFI_NOT_FOUND is returned.
@param This A pointer to this instance of the EFI_PEI_READ_ONLY_VARIABLE2_PPI.
@param VariableNameSize On entry, points to the size of the buffer pointed to by VariableName.
On return, the size of the variable name buffer.
@param VariableName On entry, a pointer to a null-terminated string that is the variable's name.
On return, points to the next variable's null-terminated name string.
@param VariableGuid On entry, a pointer to an EFI_GUID that is the variable's GUID.
On return, a pointer to the next variable's GUID.
@retval EFI_SUCCESS The variable was read successfully.
@retval EFI_NOT_FOUND The variable could not be found.
@retval EFI_BUFFER_TOO_SMALL The VariableNameSize is too small for the resulting
data. VariableNameSize is updated with the size
required for the specified variable.
@retval EFI_INVALID_PARAMETER VariableName, VariableGuid or
VariableNameSize is NULL.
@retval EFI_DEVICE_ERROR The variable could not be retrieved because of a device error.
**/
EFI_STATUS
EFIAPI
PeiGetNextVariableName (
IN CONST EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,
IN OUT UINTN *VariableNameSize,
IN OUT CHAR16 *VariableName,
IN OUT EFI_GUID *VariableGuid
)
{
VARIABLE_STORE_TYPE Type;
VARIABLE_POINTER_TRACK Variable;
VARIABLE_POINTER_TRACK VariableInHob;
VARIABLE_POINTER_TRACK VariablePtrTrack;
VARIABLE_INDEX_TABLE *IndexTable;
UINTN VarNameSize;
EFI_STATUS Status;
VARIABLE_STORE_HEADER *VariableStoreHeader[VariableStoreTypeMax];
if (VariableName == NULL || VariableGuid == NULL || VariableNameSize == NULL) {
return EFI_INVALID_PARAMETER;
}
Status = FindVariable (VariableName, VariableGuid, &Variable);
if (Variable.CurrPtr == NULL || Status != EFI_SUCCESS) {
return Status;
}
if (VariableName[0] != 0) {
//
// If variable name is not NULL, get next variable
//
Variable.CurrPtr = GetNextVariablePtr (Variable.CurrPtr);
}
VariableStoreHeader[VariableStoreTypeHob] = GetVariableStore (VariableStoreTypeHob, NULL);
VariableStoreHeader[VariableStoreTypeNv] = GetVariableStore (VariableStoreTypeNv, NULL);
while (TRUE) {
//
// Switch from HOB to Non-Volatile.
//
while ((Variable.CurrPtr >= Variable.EndPtr) ||
(Variable.CurrPtr == NULL) ||
!IsValidVariableHeader (Variable.CurrPtr)
) {
//
// Find current storage index
//
for (Type = (VARIABLE_STORE_TYPE) 0; Type < VariableStoreTypeMax; Type++) {
if ((VariableStoreHeader[Type] != NULL) && (Variable.StartPtr == GetStartPointer (VariableStoreHeader[Type]))) {
break;
}
}
ASSERT (Type < VariableStoreTypeMax);
//
// Switch to next storage
//
for (Type++; Type < VariableStoreTypeMax; Type++) {
if (VariableStoreHeader[Type] != NULL) {
break;
}
}
//
// Capture the case that
// 1. current storage is the last one, or
// 2. no further storage
//
if (Type == VariableStoreTypeMax) {
return EFI_NOT_FOUND;
}
Variable.StartPtr = GetStartPointer (VariableStoreHeader[Type]);
Variable.EndPtr = GetEndPointer (VariableStoreHeader[Type]);
Variable.CurrPtr = Variable.StartPtr;
}
if (Variable.CurrPtr->State == VAR_ADDED || Variable.CurrPtr->State == (VAR_IN_DELETED_TRANSITION & VAR_ADDED)) {
if (Variable.CurrPtr->State == (VAR_IN_DELETED_TRANSITION & VAR_ADDED)) {
//
// If it is a IN_DELETED_TRANSITION variable,
// and there is also a same ADDED one at the same time,
// don't return it.
//
for (Type = (VARIABLE_STORE_TYPE) 0; Type < VariableStoreTypeMax; Type++) {
if ((VariableStoreHeader[Type] != NULL) && (Variable.StartPtr == GetStartPointer (VariableStoreHeader[Type]))) {
break;
}
}
ASSERT (Type < VariableStoreTypeMax);
GetVariableStore (Type, &IndexTable);
Status = FindVariableEx (
VariableStoreHeader[Type],
IndexTable,
GetVariableNamePtr (Variable.CurrPtr),
&Variable.CurrPtr->VendorGuid,
&VariablePtrTrack
);
if (!EFI_ERROR (Status) && VariablePtrTrack.CurrPtr->State == VAR_ADDED) {
Variable.CurrPtr = GetNextVariablePtr (Variable.CurrPtr);
continue;
}
}
//
// Don't return NV variable when HOB overrides it
//
if ((VariableStoreHeader[VariableStoreTypeHob] != NULL) && (VariableStoreHeader[VariableStoreTypeNv] != NULL) &&
(Variable.StartPtr == GetStartPointer (VariableStoreHeader[VariableStoreTypeNv]))
) {
Status = FindVariableEx (
VariableStoreHeader[VariableStoreTypeHob],
NULL,
GetVariableNamePtr (Variable.CurrPtr),
&Variable.CurrPtr->VendorGuid,
&VariableInHob
);
if (!EFI_ERROR (Status)) {
Variable.CurrPtr = GetNextVariablePtr (Variable.CurrPtr);
continue;
}
}
VarNameSize = NameSizeOfVariable (Variable.CurrPtr);
ASSERT (VarNameSize != 0);
if (VarNameSize <= *VariableNameSize) {
CopyMem (VariableName, GetVariableNamePtr (Variable.CurrPtr), VarNameSize);
CopyMem (VariableGuid, &Variable.CurrPtr->VendorGuid, sizeof (EFI_GUID));
Status = EFI_SUCCESS;
} else {
Status = EFI_BUFFER_TOO_SMALL;
}
*VariableNameSize = VarNameSize;
//
// Variable is found
//
return Status;
} else {
Variable.CurrPtr = GetNextVariablePtr (Variable.CurrPtr);
}
}
}
|