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Change Variable driver (Pei/RuntimeDxe) to support the default variable data stored...
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1 /** @file
2
3 Implement ReadOnly Variable Services required by PEIM and install
4 PEI ReadOnly Varaiable2 PPI. These services operates the non volatile storage space.
5
6 Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
7 This program and the accompanying materials
8 are licensed and made available under the terms and conditions of the BSD License
9 which accompanies this distribution. The full text of the license may be found at
10 http://opensource.org/licenses/bsd-license.php
11
12 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
13 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
14 Module Name:
15
16 **/
17
18
19 #include "Variable.h"
20
21 //
22 // Module globals
23 //
24 EFI_PEI_READ_ONLY_VARIABLE2_PPI mVariablePpi = {
25 PeiGetVariable,
26 PeiGetNextVariableName
27 };
28
29 EFI_PEI_PPI_DESCRIPTOR mPpiListVariable = {
30 (EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
31 &gEfiPeiReadOnlyVariable2PpiGuid,
32 &mVariablePpi
33 };
34
35
36 /**
37 Provide the functionality of the variable services.
38
39 @param FileHandle Handle of the file being invoked.
40 Type EFI_PEI_FILE_HANDLE is defined in FfsFindNextFile().
41 @param PeiServices General purpose services available to every PEIM.
42
43 @retval EFI_SUCCESS If the interface could be successfully installed
44 @retval Others Returned from PeiServicesInstallPpi()
45 **/
46 EFI_STATUS
47 EFIAPI
48 PeimInitializeVariableServices (
49 IN EFI_PEI_FILE_HANDLE FileHandle,
50 IN CONST EFI_PEI_SERVICES **PeiServices
51 )
52 {
53 return PeiServicesInstallPpi (&mPpiListVariable);
54 }
55
56 /**
57
58 Gets the pointer to the first variable header in given variable store area.
59
60 @param VarStoreHeader Pointer to the Variable Store Header.
61
62 @return Pointer to the first variable header
63
64 **/
65 VARIABLE_HEADER *
66 GetStartPointer (
67 IN VARIABLE_STORE_HEADER *VarStoreHeader
68 )
69 {
70 //
71 // The end of variable store
72 //
73 return (VARIABLE_HEADER *) HEADER_ALIGN (VarStoreHeader + 1);
74 }
75
76
77 /**
78 This code gets the pointer to the last variable memory pointer byte.
79
80 @param VarStoreHeader Pointer to the Variable Store Header.
81
82 @return VARIABLE_HEADER* pointer to last unavailable Variable Header.
83
84 **/
85 VARIABLE_HEADER *
86 GetEndPointer (
87 IN VARIABLE_STORE_HEADER *VarStoreHeader
88 )
89 {
90 //
91 // The end of variable store
92 //
93 return (VARIABLE_HEADER *) HEADER_ALIGN ((UINTN) VarStoreHeader + VarStoreHeader->Size);
94 }
95
96
97 /**
98 This code checks if variable header is valid or not.
99
100 @param Variable Pointer to the Variable Header.
101
102 @retval TRUE Variable header is valid.
103 @retval FALSE Variable header is not valid.
104
105 **/
106 BOOLEAN
107 IsValidVariableHeader (
108 IN VARIABLE_HEADER *Variable
109 )
110 {
111 if (Variable == NULL || Variable->StartId != VARIABLE_DATA ) {
112 return FALSE;
113 }
114
115 return TRUE;
116 }
117
118
119 /**
120 This code gets the size of name of variable.
121
122 @param Variable Pointer to the Variable Header.
123
124 @return Size of variable in bytes in type UINTN.
125
126 **/
127 UINTN
128 NameSizeOfVariable (
129 IN VARIABLE_HEADER *Variable
130 )
131 {
132 if (Variable->State == (UINT8) (-1) ||
133 Variable->DataSize == (UINT32) (-1) ||
134 Variable->NameSize == (UINT32) (-1) ||
135 Variable->Attributes == (UINT32) (-1)) {
136 return 0;
137 }
138 return (UINTN) Variable->NameSize;
139 }
140
141
142 /**
143 This code gets the size of data of variable.
144
145 @param Variable Pointer to the Variable Header.
146
147 @return Size of variable in bytes in type UINTN.
148
149 **/
150 UINTN
151 DataSizeOfVariable (
152 IN VARIABLE_HEADER *Variable
153 )
154 {
155 if (Variable->State == (UINT8) (-1) ||
156 Variable->DataSize == (UINT32) (-1) ||
157 Variable->NameSize == (UINT32) (-1) ||
158 Variable->Attributes == (UINT32) (-1)) {
159 return 0;
160 }
161 return (UINTN) Variable->DataSize;
162 }
163
164 /**
165 This code gets the pointer to the variable name.
166
167 @param Variable Pointer to the Variable Header.
168
169 @return A CHAR16* pointer to Variable Name.
170
171 **/
172 CHAR16 *
173 GetVariableNamePtr (
174 IN VARIABLE_HEADER *Variable
175 )
176 {
177
178 return (CHAR16 *) (Variable + 1);
179 }
180
181
182 /**
183 This code gets the pointer to the variable data.
184
185 @param Variable Pointer to the Variable Header.
186
187 @return A UINT8* pointer to Variable Data.
188
189 **/
190 UINT8 *
191 GetVariableDataPtr (
192 IN VARIABLE_HEADER *Variable
193 )
194 {
195 UINTN Value;
196
197 //
198 // Be careful about pad size for alignment
199 //
200 Value = (UINTN) GetVariableNamePtr (Variable);
201 Value += NameSizeOfVariable (Variable);
202 Value += GET_PAD_SIZE (NameSizeOfVariable (Variable));
203
204 return (UINT8 *) Value;
205 }
206
207
208 /**
209 This code gets the pointer to the next variable header.
210
211 @param Variable Pointer to the Variable Header.
212
213 @return A VARIABLE_HEADER* pointer to next variable header.
214
215 **/
216 VARIABLE_HEADER *
217 GetNextVariablePtr (
218 IN VARIABLE_HEADER *Variable
219 )
220 {
221 UINTN Value;
222
223 if (!IsValidVariableHeader (Variable)) {
224 return NULL;
225 }
226
227 Value = (UINTN) GetVariableDataPtr (Variable);
228 Value += DataSizeOfVariable (Variable);
229 Value += GET_PAD_SIZE (DataSizeOfVariable (Variable));
230
231 //
232 // Be careful about pad size for alignment
233 //
234 return (VARIABLE_HEADER *) HEADER_ALIGN (Value);
235 }
236
237 /**
238 This code gets the pointer to the variable name.
239
240 @param VarStoreHeader Pointer to the Variable Store Header.
241
242 @retval EfiRaw Variable store is raw
243 @retval EfiValid Variable store is valid
244 @retval EfiInvalid Variable store is invalid
245
246 **/
247 VARIABLE_STORE_STATUS
248 GetVariableStoreStatus (
249 IN VARIABLE_STORE_HEADER *VarStoreHeader
250 )
251 {
252
253 if (CompareGuid (&VarStoreHeader->Signature, &gEfiVariableGuid) &&
254 VarStoreHeader->Format == VARIABLE_STORE_FORMATTED &&
255 VarStoreHeader->State == VARIABLE_STORE_HEALTHY
256 ) {
257
258 return EfiValid;
259 }
260
261 if (((UINT32 *)(&VarStoreHeader->Signature))[0] == 0xffffffff &&
262 ((UINT32 *)(&VarStoreHeader->Signature))[1] == 0xffffffff &&
263 ((UINT32 *)(&VarStoreHeader->Signature))[2] == 0xffffffff &&
264 ((UINT32 *)(&VarStoreHeader->Signature))[3] == 0xffffffff &&
265 VarStoreHeader->Size == 0xffffffff &&
266 VarStoreHeader->Format == 0xff &&
267 VarStoreHeader->State == 0xff
268 ) {
269
270 return EfiRaw;
271 } else {
272 return EfiInvalid;
273 }
274 }
275
276
277 /**
278 This function compares a variable with variable entries in database.
279
280 @param Variable Pointer to the variable in our database
281 @param VariableName Name of the variable to compare to 'Variable'
282 @param VendorGuid GUID of the variable to compare to 'Variable'
283 @param PtrTrack Variable Track Pointer structure that contains Variable Information.
284
285 @retval EFI_SUCCESS Found match variable
286 @retval EFI_NOT_FOUND Variable not found
287
288 **/
289 EFI_STATUS
290 CompareWithValidVariable (
291 IN VARIABLE_HEADER *Variable,
292 IN CONST CHAR16 *VariableName,
293 IN CONST EFI_GUID *VendorGuid,
294 OUT VARIABLE_POINTER_TRACK *PtrTrack
295 )
296 {
297 VOID *Point;
298
299 if (VariableName[0] == 0) {
300 PtrTrack->CurrPtr = Variable;
301 return EFI_SUCCESS;
302 } else {
303 //
304 // Don't use CompareGuid function here for performance reasons.
305 // Instead we compare the GUID a UINT32 at a time and branch
306 // on the first failed comparison.
307 //
308 if ((((INT32 *) VendorGuid)[0] == ((INT32 *) &Variable->VendorGuid)[0]) &&
309 (((INT32 *) VendorGuid)[1] == ((INT32 *) &Variable->VendorGuid)[1]) &&
310 (((INT32 *) VendorGuid)[2] == ((INT32 *) &Variable->VendorGuid)[2]) &&
311 (((INT32 *) VendorGuid)[3] == ((INT32 *) &Variable->VendorGuid)[3])
312 ) {
313 ASSERT (NameSizeOfVariable (Variable) != 0);
314 Point = (VOID *) GetVariableNamePtr (Variable);
315 if (CompareMem (VariableName, Point, NameSizeOfVariable (Variable)) == 0) {
316 PtrTrack->CurrPtr = Variable;
317 return EFI_SUCCESS;
318 }
319 }
320 }
321
322 return EFI_NOT_FOUND;
323 }
324
325 /**
326 Return the variable store header and the index table based on the Index.
327
328 @param Index The index of the variable store.
329 @param IndexTable Return the index table.
330
331 @return Pointer to the variable store header.
332 **/
333 VARIABLE_STORE_HEADER *
334 GetVariableStore (
335 IN VARIABLE_STORE_TYPE Type,
336 OUT VARIABLE_INDEX_TABLE **IndexTable OPTIONAL
337 )
338 {
339 EFI_HOB_GUID_TYPE *GuidHob;
340 EFI_FIRMWARE_VOLUME_HEADER *FvHeader;
341 VARIABLE_STORE_HEADER *VariableStoreHeader;
342
343 if (IndexTable != NULL) {
344 *IndexTable = NULL;
345 }
346 VariableStoreHeader = NULL;
347 switch (Type) {
348 case VariableStoreTypeHob:
349 GuidHob = GetFirstGuidHob (&gEfiVariableGuid);
350 if (GuidHob != NULL) {
351 VariableStoreHeader = (VARIABLE_STORE_HEADER *) GET_GUID_HOB_DATA (GuidHob);
352 }
353 break;
354
355 case VariableStoreTypeNv:
356 if (GetBootModeHob () != BOOT_IN_RECOVERY_MODE) {
357 //
358 // The content of NV storage for variable is not reliable in recovery boot mode.
359 //
360 FvHeader = (EFI_FIRMWARE_VOLUME_HEADER *) (UINTN) (PcdGet64 (PcdFlashNvStorageVariableBase64) != 0 ?
361 PcdGet64 (PcdFlashNvStorageVariableBase64) :
362 PcdGet32 (PcdFlashNvStorageVariableBase)
363 );
364 VariableStoreHeader = (VARIABLE_STORE_HEADER *) ((UINT8 *) FvHeader + FvHeader->HeaderLength);
365
366 if (IndexTable != NULL) {
367 GuidHob = GetFirstGuidHob (&gEfiVariableIndexTableGuid);
368 if (GuidHob != NULL) {
369 *IndexTable = GET_GUID_HOB_DATA (GuidHob);
370 } else {
371 //
372 // If it's the first time to access variable region in flash, create a guid hob to record
373 // VAR_ADDED type variable info.
374 // Note that as the resource of PEI phase is limited, only store the limited number of
375 // VAR_ADDED type variables to reduce access time.
376 //
377 *IndexTable = BuildGuidHob (&gEfiVariableIndexTableGuid, sizeof (VARIABLE_INDEX_TABLE));
378 (*IndexTable)->Length = 0;
379 (*IndexTable)->StartPtr = GetStartPointer (VariableStoreHeader);
380 (*IndexTable)->EndPtr = GetEndPointer (VariableStoreHeader);
381 (*IndexTable)->GoneThrough = 0;
382 }
383 }
384 }
385 break;
386 }
387
388 return VariableStoreHeader;
389 }
390
391 /**
392 Find the variable in the specified variable store.
393
394 @param VariableStoreHeader Pointer to the variable store header.
395 @param IndexTable Pointer to the index table.
396 @param VariableName Name of the variable to be found
397 @param VendorGuid Vendor GUID to be found.
398 @param PtrTrack Variable Track Pointer structure that contains Variable Information.
399
400 @retval EFI_SUCCESS Variable found successfully
401 @retval EFI_NOT_FOUND Variable not found
402 @retval EFI_INVALID_PARAMETER Invalid variable name
403
404 **/
405 EFI_STATUS
406 FindVariableEx (
407 IN VARIABLE_STORE_HEADER *VariableStoreHeader,
408 IN VARIABLE_INDEX_TABLE *IndexTable,
409 IN CONST CHAR16 *VariableName,
410 IN CONST EFI_GUID *VendorGuid,
411 OUT VARIABLE_POINTER_TRACK *PtrTrack
412 )
413 {
414 VARIABLE_HEADER *Variable;
415 VARIABLE_HEADER *LastVariable;
416 VARIABLE_HEADER *MaxIndex;
417 UINTN Index;
418 UINTN Offset;
419 BOOLEAN StopRecord;
420
421 if (VariableStoreHeader == NULL) {
422 return EFI_INVALID_PARAMETER;
423 }
424
425 if (GetVariableStoreStatus (VariableStoreHeader) != EfiValid) {
426 return EFI_UNSUPPORTED;
427 }
428
429 if (~VariableStoreHeader->Size == 0) {
430 return EFI_NOT_FOUND;
431 }
432
433 PtrTrack->StartPtr = GetStartPointer (VariableStoreHeader);
434 PtrTrack->EndPtr = GetEndPointer (VariableStoreHeader);
435
436 //
437 // No Variable Address equals zero, so 0 as initial value is safe.
438 //
439 MaxIndex = NULL;
440
441 if (IndexTable != NULL) {
442 //
443 // traverse the variable index table to look for varible.
444 // The IndexTable->Index[Index] records the distance of two neighbouring VAR_ADDED type variables.
445 //
446 for (Offset = 0, Index = 0; Index < IndexTable->Length; Index++) {
447 ASSERT (Index < sizeof (IndexTable->Index) / sizeof (IndexTable->Index[0]));
448 Offset += IndexTable->Index[Index];
449 MaxIndex = (VARIABLE_HEADER *) ((UINT8 *) IndexTable->StartPtr + Offset);
450 if (CompareWithValidVariable (MaxIndex, VariableName, VendorGuid, PtrTrack) == EFI_SUCCESS) {
451 return EFI_SUCCESS;
452 }
453 }
454
455 if (IndexTable->GoneThrough != 0) {
456 //
457 // If the table has all the existing variables indexed and we still cannot find it.
458 //
459 return EFI_NOT_FOUND;
460 }
461 }
462
463 if (MaxIndex != NULL) {
464 //
465 // HOB exists but the variable cannot be found in HOB
466 // If not found in HOB, then let's start from the MaxIndex we've found.
467 //
468 Variable = GetNextVariablePtr (MaxIndex);
469 LastVariable = MaxIndex;
470 } else {
471 //
472 // Start Pointers for the variable.
473 // Actual Data Pointer where data can be written.
474 //
475 Variable = PtrTrack->StartPtr;
476 LastVariable = PtrTrack->StartPtr;
477 }
478
479 //
480 // Find the variable by walk through non-volatile variable store
481 //
482 StopRecord = FALSE;
483 while ((Variable < PtrTrack->EndPtr) && IsValidVariableHeader (Variable)) {
484 if (Variable->State == VAR_ADDED) {
485 //
486 // Record Variable in VariableIndex HOB
487 //
488 if ((IndexTable != NULL) && !StopRecord) {
489 Offset = (UINTN) Variable - (UINTN) LastVariable;
490 if ((Offset > 0x0FFFF) || (IndexTable->Length == sizeof (IndexTable->Index) / sizeof (IndexTable->Index[0]))) {
491 //
492 // Stop to record if the distance of two neighbouring VAR_ADDED variable is larger than the allowable scope(UINT16),
493 // or the record buffer is full.
494 //
495 StopRecord = TRUE;
496 } else {
497 IndexTable->Index[IndexTable->Length++] = (UINT16) Offset;
498 LastVariable = Variable;
499 }
500 }
501
502 if (CompareWithValidVariable (Variable, VariableName, VendorGuid, PtrTrack) == EFI_SUCCESS) {
503 return EFI_SUCCESS;
504 }
505 }
506
507 Variable = GetNextVariablePtr (Variable);
508 }
509 //
510 // If gone through the VariableStore, that means we never find in Firmware any more.
511 //
512 if ((IndexTable != NULL) && !StopRecord) {
513 IndexTable->GoneThrough = 1;
514 }
515
516 PtrTrack->CurrPtr = NULL;
517
518 return EFI_NOT_FOUND;
519 }
520
521 /**
522 Find the variable in HOB and Non-Volatile variable storages.
523
524 @param VariableName Name of the variable to be found
525 @param VendorGuid Vendor GUID to be found.
526 @param PtrTrack Variable Track Pointer structure that contains Variable Information.
527
528 @retval EFI_SUCCESS Variable found successfully
529 @retval EFI_NOT_FOUND Variable not found
530 @retval EFI_INVALID_PARAMETER Invalid variable name
531 **/
532 EFI_STATUS
533 FindVariable (
534 IN CONST CHAR16 *VariableName,
535 IN CONST EFI_GUID *VendorGuid,
536 OUT VARIABLE_POINTER_TRACK *PtrTrack
537 )
538 {
539 EFI_STATUS Status;
540 VARIABLE_STORE_HEADER *VariableStoreHeader;
541 VARIABLE_INDEX_TABLE *IndexTable;
542 VARIABLE_STORE_TYPE Type;
543
544 if (VariableName[0] != 0 && VendorGuid == NULL) {
545 return EFI_INVALID_PARAMETER;
546 }
547
548 for (Type = (VARIABLE_STORE_TYPE) 0; Type < VariableStoreTypeMax; Type++) {
549 VariableStoreHeader = GetVariableStore (Type, &IndexTable);
550 Status = FindVariableEx (
551 VariableStoreHeader,
552 IndexTable,
553 VariableName,
554 VendorGuid,
555 PtrTrack
556 );
557 if (!EFI_ERROR (Status)) {
558 return Status;
559 }
560 }
561
562 return EFI_NOT_FOUND;
563 }
564
565 /**
566 This service retrieves a variable's value using its name and GUID.
567
568 Read the specified variable from the UEFI variable store. If the Data
569 buffer is too small to hold the contents of the variable, the error
570 EFI_BUFFER_TOO_SMALL is returned and DataSize is set to the required buffer
571 size to obtain the data.
572
573 @param This A pointer to this instance of the EFI_PEI_READ_ONLY_VARIABLE2_PPI.
574 @param VariableName A pointer to a null-terminated string that is the variable's name.
575 @param VariableGuid A pointer to an EFI_GUID that is the variable's GUID. The combination of
576 VariableGuid and VariableName must be unique.
577 @param Attributes If non-NULL, on return, points to the variable's attributes.
578 @param DataSize On entry, points to the size in bytes of the Data buffer.
579 On return, points to the size of the data returned in Data.
580 @param Data Points to the buffer which will hold the returned variable value.
581
582 @retval EFI_SUCCESS The variable was read successfully.
583 @retval EFI_NOT_FOUND The variable could not be found.
584 @retval EFI_BUFFER_TOO_SMALL The DataSize is too small for the resulting data.
585 DataSize is updated with the size required for
586 the specified variable.
587 @retval EFI_INVALID_PARAMETER VariableName, VariableGuid, DataSize or Data is NULL.
588 @retval EFI_DEVICE_ERROR The variable could not be retrieved because of a device error.
589
590 **/
591 EFI_STATUS
592 EFIAPI
593 PeiGetVariable (
594 IN CONST EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,
595 IN CONST CHAR16 *VariableName,
596 IN CONST EFI_GUID *VariableGuid,
597 OUT UINT32 *Attributes,
598 IN OUT UINTN *DataSize,
599 OUT VOID *Data
600 )
601 {
602 VARIABLE_POINTER_TRACK Variable;
603 UINTN VarDataSize;
604 EFI_STATUS Status;
605
606 if (VariableName == NULL || VariableGuid == NULL || DataSize == NULL) {
607 return EFI_INVALID_PARAMETER;
608 }
609
610 //
611 // Find existing variable
612 //
613 Status = FindVariable (VariableName, VariableGuid, &Variable);
614 if (EFI_ERROR (Status)) {
615 return Status;
616 }
617 //
618 // Get data size
619 //
620 VarDataSize = DataSizeOfVariable (Variable.CurrPtr);
621 if (*DataSize >= VarDataSize) {
622 if (Data == NULL) {
623 return EFI_INVALID_PARAMETER;
624 }
625
626 CopyMem (Data, GetVariableDataPtr (Variable.CurrPtr), VarDataSize);
627
628 if (Attributes != NULL) {
629 *Attributes = Variable.CurrPtr->Attributes;
630 }
631
632 *DataSize = VarDataSize;
633 return EFI_SUCCESS;
634 } else {
635 *DataSize = VarDataSize;
636 return EFI_BUFFER_TOO_SMALL;
637 }
638 }
639
640 /**
641 Return the next variable name and GUID.
642
643 This function is called multiple times to retrieve the VariableName
644 and VariableGuid of all variables currently available in the system.
645 On each call, the previous results are passed into the interface,
646 and, on return, the interface returns the data for the next
647 interface. When the entire variable list has been returned,
648 EFI_NOT_FOUND is returned.
649
650 @param This A pointer to this instance of the EFI_PEI_READ_ONLY_VARIABLE2_PPI.
651
652 @param VariableNameSize On entry, points to the size of the buffer pointed to by VariableName.
653 On return, the size of the variable name buffer.
654 @param VariableName On entry, a pointer to a null-terminated string that is the variable's name.
655 On return, points to the next variable's null-terminated name string.
656 @param VariableGuid On entry, a pointer to an EFI_GUID that is the variable's GUID.
657 On return, a pointer to the next variable's GUID.
658
659 @retval EFI_SUCCESS The variable was read successfully.
660 @retval EFI_NOT_FOUND The variable could not be found.
661 @retval EFI_BUFFER_TOO_SMALL The VariableNameSize is too small for the resulting
662 data. VariableNameSize is updated with the size
663 required for the specified variable.
664 @retval EFI_INVALID_PARAMETER VariableName, VariableGuid or
665 VariableNameSize is NULL.
666 @retval EFI_DEVICE_ERROR The variable could not be retrieved because of a device error.
667
668 **/
669 EFI_STATUS
670 EFIAPI
671 PeiGetNextVariableName (
672 IN CONST EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,
673 IN OUT UINTN *VariableNameSize,
674 IN OUT CHAR16 *VariableName,
675 IN OUT EFI_GUID *VariableGuid
676 )
677 {
678 VARIABLE_STORE_TYPE Type;
679 VARIABLE_POINTER_TRACK Variable;
680 VARIABLE_POINTER_TRACK VariableInHob;
681 UINTN VarNameSize;
682 EFI_STATUS Status;
683 VARIABLE_STORE_HEADER *VariableStoreHeader[VariableStoreTypeMax];
684
685 if (VariableName == NULL || VariableGuid == NULL || VariableNameSize == NULL) {
686 return EFI_INVALID_PARAMETER;
687 }
688
689 Status = FindVariable (VariableName, VariableGuid, &Variable);
690 if (Variable.CurrPtr == NULL || Status != EFI_SUCCESS) {
691 return Status;
692 }
693
694 if (VariableName[0] != 0) {
695 //
696 // If variable name is not NULL, get next variable
697 //
698 Variable.CurrPtr = GetNextVariablePtr (Variable.CurrPtr);
699 }
700
701 VariableStoreHeader[VariableStoreTypeHob] = GetVariableStore (VariableStoreTypeHob, NULL);
702 VariableStoreHeader[VariableStoreTypeNv] = GetVariableStore (VariableStoreTypeNv, NULL);
703
704 while (TRUE) {
705 //
706 // Switch from HOB to Non-Volatile.
707 //
708 while ((Variable.CurrPtr >= Variable.EndPtr) ||
709 (Variable.CurrPtr == NULL) ||
710 !IsValidVariableHeader (Variable.CurrPtr)
711 ) {
712 //
713 // Find current storage index
714 //
715 for (Type = (VARIABLE_STORE_TYPE) 0; Type < VariableStoreTypeMax; Type++) {
716 if ((VariableStoreHeader[Type] != NULL) && (Variable.StartPtr == GetStartPointer (VariableStoreHeader[Type]))) {
717 break;
718 }
719 }
720 ASSERT (Type < VariableStoreTypeMax);
721 //
722 // Switch to next storage
723 //
724 for (Type++; Type < VariableStoreTypeMax; Type++) {
725 if (VariableStoreHeader[Type] != NULL) {
726 break;
727 }
728 }
729 //
730 // Capture the case that
731 // 1. current storage is the last one, or
732 // 2. no further storage
733 //
734 if (Type == VariableStoreTypeMax) {
735 return EFI_NOT_FOUND;
736 }
737 Variable.StartPtr = GetStartPointer (VariableStoreHeader[Type]);
738 Variable.EndPtr = GetEndPointer (VariableStoreHeader[Type]);
739 Variable.CurrPtr = Variable.StartPtr;
740 }
741
742 if (Variable.CurrPtr->State == VAR_ADDED) {
743
744 //
745 // Don't return NV variable when HOB overrides it
746 //
747 if ((VariableStoreHeader[VariableStoreTypeHob] != NULL) && (VariableStoreHeader[VariableStoreTypeNv] != NULL) &&
748 (Variable.StartPtr == GetStartPointer (VariableStoreHeader[VariableStoreTypeNv]))
749 ) {
750 Status = FindVariableEx (
751 VariableStoreHeader[VariableStoreTypeHob],
752 NULL,
753 GetVariableNamePtr (Variable.CurrPtr),
754 &Variable.CurrPtr->VendorGuid,
755 &VariableInHob
756 );
757 if (!EFI_ERROR (Status)) {
758 Variable.CurrPtr = GetNextVariablePtr (Variable.CurrPtr);
759 continue;
760 }
761 }
762
763 VarNameSize = NameSizeOfVariable (Variable.CurrPtr);
764 ASSERT (VarNameSize != 0);
765
766 if (VarNameSize <= *VariableNameSize) {
767 CopyMem (VariableName, GetVariableNamePtr (Variable.CurrPtr), VarNameSize);
768
769 CopyMem (VariableGuid, &Variable.CurrPtr->VendorGuid, sizeof (EFI_GUID));
770
771 Status = EFI_SUCCESS;
772 } else {
773 Status = EFI_BUFFER_TOO_SMALL;
774 }
775
776 *VariableNameSize = VarNameSize;
777 //
778 // Variable is found
779 //
780 return Status;
781 } else {
782 Variable.CurrPtr = GetNextVariablePtr (Variable.CurrPtr);
783 }
784 }
785 }
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