3 Implement ReadOnly Variable Services required by PEIM and install
4 PEI ReadOnly Varaiable2 PPI. These services operates the non volatile storage space.
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
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.
24 EFI_PEI_READ_ONLY_VARIABLE2_PPI mVariablePpi
= {
26 PeiGetNextVariableName
29 EFI_PEI_PPI_DESCRIPTOR mPpiListVariable
= {
30 (EFI_PEI_PPI_DESCRIPTOR_PPI
| EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST
),
31 &gEfiPeiReadOnlyVariable2PpiGuid
,
37 Provide the functionality of the variable services.
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.
43 @retval EFI_SUCCESS If the interface could be successfully installed
44 @retval Others Returned from PeiServicesInstallPpi()
48 PeimInitializeVariableServices (
49 IN EFI_PEI_FILE_HANDLE FileHandle
,
50 IN CONST EFI_PEI_SERVICES
**PeiServices
53 return PeiServicesInstallPpi (&mPpiListVariable
);
58 Gets the pointer to the first variable header in given variable store area.
60 @param VarStoreHeader Pointer to the Variable Store Header.
62 @return Pointer to the first variable header
67 IN VARIABLE_STORE_HEADER
*VarStoreHeader
71 // The end of variable store
73 return (VARIABLE_HEADER
*) HEADER_ALIGN (VarStoreHeader
+ 1);
78 This code gets the pointer to the last variable memory pointer byte.
80 @param VarStoreHeader Pointer to the Variable Store Header.
82 @return VARIABLE_HEADER* pointer to last unavailable Variable Header.
87 IN VARIABLE_STORE_HEADER
*VarStoreHeader
91 // The end of variable store
93 return (VARIABLE_HEADER
*) HEADER_ALIGN ((UINTN
) VarStoreHeader
+ VarStoreHeader
->Size
);
98 This code checks if variable header is valid or not.
100 @param Variable Pointer to the Variable Header.
102 @retval TRUE Variable header is valid.
103 @retval FALSE Variable header is not valid.
107 IsValidVariableHeader (
108 IN VARIABLE_HEADER
*Variable
111 if (Variable
== NULL
|| Variable
->StartId
!= VARIABLE_DATA
) {
120 This code gets the size of name of variable.
122 @param Variable Pointer to the Variable Header.
124 @return Size of variable in bytes in type UINTN.
129 IN VARIABLE_HEADER
*Variable
132 if (Variable
->State
== (UINT8
) (-1) ||
133 Variable
->DataSize
== (UINT32
) (-1) ||
134 Variable
->NameSize
== (UINT32
) (-1) ||
135 Variable
->Attributes
== (UINT32
) (-1)) {
138 return (UINTN
) Variable
->NameSize
;
143 This code gets the size of data of variable.
145 @param Variable Pointer to the Variable Header.
147 @return Size of variable in bytes in type UINTN.
152 IN VARIABLE_HEADER
*Variable
155 if (Variable
->State
== (UINT8
) (-1) ||
156 Variable
->DataSize
== (UINT32
) (-1) ||
157 Variable
->NameSize
== (UINT32
) (-1) ||
158 Variable
->Attributes
== (UINT32
) (-1)) {
161 return (UINTN
) Variable
->DataSize
;
165 This code gets the pointer to the variable name.
167 @param Variable Pointer to the Variable Header.
169 @return A CHAR16* pointer to Variable Name.
174 IN VARIABLE_HEADER
*Variable
178 return (CHAR16
*) (Variable
+ 1);
183 This code gets the pointer to the variable data.
185 @param Variable Pointer to the Variable Header.
187 @return A UINT8* pointer to Variable Data.
192 IN VARIABLE_HEADER
*Variable
198 // Be careful about pad size for alignment
200 Value
= (UINTN
) GetVariableNamePtr (Variable
);
201 Value
+= NameSizeOfVariable (Variable
);
202 Value
+= GET_PAD_SIZE (NameSizeOfVariable (Variable
));
204 return (UINT8
*) Value
;
209 This code gets the pointer to the next variable header.
211 @param Variable Pointer to the Variable Header.
213 @return A VARIABLE_HEADER* pointer to next variable header.
218 IN VARIABLE_HEADER
*Variable
223 if (!IsValidVariableHeader (Variable
)) {
227 Value
= (UINTN
) GetVariableDataPtr (Variable
);
228 Value
+= DataSizeOfVariable (Variable
);
229 Value
+= GET_PAD_SIZE (DataSizeOfVariable (Variable
));
232 // Be careful about pad size for alignment
234 return (VARIABLE_HEADER
*) HEADER_ALIGN (Value
);
238 This code gets the pointer to the variable name.
240 @param VarStoreHeader Pointer to the Variable Store Header.
242 @retval EfiRaw Variable store is raw
243 @retval EfiValid Variable store is valid
244 @retval EfiInvalid Variable store is invalid
247 VARIABLE_STORE_STATUS
248 GetVariableStoreStatus (
249 IN VARIABLE_STORE_HEADER
*VarStoreHeader
253 if (CompareGuid (&VarStoreHeader
->Signature
, &gEfiVariableGuid
) &&
254 VarStoreHeader
->Format
== VARIABLE_STORE_FORMATTED
&&
255 VarStoreHeader
->State
== VARIABLE_STORE_HEALTHY
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
278 This function compares a variable with variable entries in database.
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.
285 @retval EFI_SUCCESS Found match variable
286 @retval EFI_NOT_FOUND Variable not found
290 CompareWithValidVariable (
291 IN VARIABLE_HEADER
*Variable
,
292 IN CONST CHAR16
*VariableName
,
293 IN CONST EFI_GUID
*VendorGuid
,
294 OUT VARIABLE_POINTER_TRACK
*PtrTrack
299 if (VariableName
[0] == 0) {
300 PtrTrack
->CurrPtr
= Variable
;
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.
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])
313 ASSERT (NameSizeOfVariable (Variable
) != 0);
314 Point
= (VOID
*) GetVariableNamePtr (Variable
);
315 if (CompareMem (VariableName
, Point
, NameSizeOfVariable (Variable
)) == 0) {
316 PtrTrack
->CurrPtr
= Variable
;
322 return EFI_NOT_FOUND
;
326 Return the variable store header and the index table based on the Index.
328 @param Type The type of the variable store.
329 @param IndexTable Return the index table.
331 @return Pointer to the variable store header.
333 VARIABLE_STORE_HEADER
*
335 IN VARIABLE_STORE_TYPE Type
,
336 OUT VARIABLE_INDEX_TABLE
**IndexTable OPTIONAL
339 EFI_HOB_GUID_TYPE
*GuidHob
;
340 EFI_FIRMWARE_VOLUME_HEADER
*FvHeader
;
341 VARIABLE_STORE_HEADER
*VariableStoreHeader
;
343 if (IndexTable
!= NULL
) {
346 VariableStoreHeader
= NULL
;
348 case VariableStoreTypeHob
:
349 GuidHob
= GetFirstGuidHob (&gEfiVariableGuid
);
350 if (GuidHob
!= NULL
) {
351 VariableStoreHeader
= (VARIABLE_STORE_HEADER
*) GET_GUID_HOB_DATA (GuidHob
);
355 case VariableStoreTypeNv
:
356 if (GetBootModeHob () != BOOT_IN_RECOVERY_MODE
) {
358 // The content of NV storage for variable is not reliable in recovery boot mode.
360 FvHeader
= (EFI_FIRMWARE_VOLUME_HEADER
*) (UINTN
) (PcdGet64 (PcdFlashNvStorageVariableBase64
) != 0 ?
361 PcdGet64 (PcdFlashNvStorageVariableBase64
) :
362 PcdGet32 (PcdFlashNvStorageVariableBase
)
364 VariableStoreHeader
= (VARIABLE_STORE_HEADER
*) ((UINT8
*) FvHeader
+ FvHeader
->HeaderLength
);
366 if (IndexTable
!= NULL
) {
367 GuidHob
= GetFirstGuidHob (&gEfiVariableIndexTableGuid
);
368 if (GuidHob
!= NULL
) {
369 *IndexTable
= GET_GUID_HOB_DATA (GuidHob
);
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.
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;
392 return VariableStoreHeader
;
396 Find the variable in the specified variable store.
398 @param VariableStoreHeader Pointer to the variable store header.
399 @param IndexTable Pointer to the index table.
400 @param VariableName Name of the variable to be found
401 @param VendorGuid Vendor GUID to be found.
402 @param PtrTrack Variable Track Pointer structure that contains Variable Information.
404 @retval EFI_SUCCESS Variable found successfully
405 @retval EFI_NOT_FOUND Variable not found
406 @retval EFI_INVALID_PARAMETER Invalid variable name
411 IN VARIABLE_STORE_HEADER
*VariableStoreHeader
,
412 IN VARIABLE_INDEX_TABLE
*IndexTable
,
413 IN CONST CHAR16
*VariableName
,
414 IN CONST EFI_GUID
*VendorGuid
,
415 OUT VARIABLE_POINTER_TRACK
*PtrTrack
418 VARIABLE_HEADER
*Variable
;
419 VARIABLE_HEADER
*LastVariable
;
420 VARIABLE_HEADER
*MaxIndex
;
425 if (VariableStoreHeader
== NULL
) {
426 return EFI_INVALID_PARAMETER
;
429 if (GetVariableStoreStatus (VariableStoreHeader
) != EfiValid
) {
430 return EFI_UNSUPPORTED
;
433 if (~VariableStoreHeader
->Size
== 0) {
434 return EFI_NOT_FOUND
;
437 PtrTrack
->StartPtr
= GetStartPointer (VariableStoreHeader
);
438 PtrTrack
->EndPtr
= GetEndPointer (VariableStoreHeader
);
441 // No Variable Address equals zero, so 0 as initial value is safe.
445 if (IndexTable
!= NULL
) {
447 // traverse the variable index table to look for varible.
448 // The IndexTable->Index[Index] records the distance of two neighbouring VAR_ADDED type variables.
450 for (Offset
= 0, Index
= 0; Index
< IndexTable
->Length
; Index
++) {
451 ASSERT (Index
< sizeof (IndexTable
->Index
) / sizeof (IndexTable
->Index
[0]));
452 Offset
+= IndexTable
->Index
[Index
];
453 MaxIndex
= (VARIABLE_HEADER
*) ((UINT8
*) IndexTable
->StartPtr
+ Offset
);
454 if (CompareWithValidVariable (MaxIndex
, VariableName
, VendorGuid
, PtrTrack
) == EFI_SUCCESS
) {
459 if (IndexTable
->GoneThrough
!= 0) {
461 // If the table has all the existing variables indexed and we still cannot find it.
463 return EFI_NOT_FOUND
;
467 if (MaxIndex
!= NULL
) {
469 // HOB exists but the variable cannot be found in HOB
470 // If not found in HOB, then let's start from the MaxIndex we've found.
472 Variable
= GetNextVariablePtr (MaxIndex
);
473 LastVariable
= MaxIndex
;
476 // Start Pointers for the variable.
477 // Actual Data Pointer where data can be written.
479 Variable
= PtrTrack
->StartPtr
;
480 LastVariable
= PtrTrack
->StartPtr
;
484 // Find the variable by walk through non-volatile variable store
487 while ((Variable
< PtrTrack
->EndPtr
) && IsValidVariableHeader (Variable
)) {
488 if (Variable
->State
== VAR_ADDED
) {
490 // Record Variable in VariableIndex HOB
492 if ((IndexTable
!= NULL
) && !StopRecord
) {
493 Offset
= (UINTN
) Variable
- (UINTN
) LastVariable
;
494 if ((Offset
> 0x0FFFF) || (IndexTable
->Length
== sizeof (IndexTable
->Index
) / sizeof (IndexTable
->Index
[0]))) {
496 // Stop to record if the distance of two neighbouring VAR_ADDED variable is larger than the allowable scope(UINT16),
497 // or the record buffer is full.
501 IndexTable
->Index
[IndexTable
->Length
++] = (UINT16
) Offset
;
502 LastVariable
= Variable
;
506 if (CompareWithValidVariable (Variable
, VariableName
, VendorGuid
, PtrTrack
) == EFI_SUCCESS
) {
511 Variable
= GetNextVariablePtr (Variable
);
514 // If gone through the VariableStore, that means we never find in Firmware any more.
516 if ((IndexTable
!= NULL
) && !StopRecord
) {
517 IndexTable
->GoneThrough
= 1;
520 PtrTrack
->CurrPtr
= NULL
;
522 return EFI_NOT_FOUND
;
526 Find the variable in HOB and Non-Volatile variable storages.
528 @param VariableName Name of the variable to be found
529 @param VendorGuid Vendor GUID to be found.
530 @param PtrTrack Variable Track Pointer structure that contains Variable Information.
532 @retval EFI_SUCCESS Variable found successfully
533 @retval EFI_NOT_FOUND Variable not found
534 @retval EFI_INVALID_PARAMETER Invalid variable name
538 IN CONST CHAR16
*VariableName
,
539 IN CONST EFI_GUID
*VendorGuid
,
540 OUT VARIABLE_POINTER_TRACK
*PtrTrack
544 VARIABLE_STORE_HEADER
*VariableStoreHeader
;
545 VARIABLE_INDEX_TABLE
*IndexTable
;
546 VARIABLE_STORE_TYPE Type
;
548 if (VariableName
[0] != 0 && VendorGuid
== NULL
) {
549 return EFI_INVALID_PARAMETER
;
552 for (Type
= (VARIABLE_STORE_TYPE
) 0; Type
< VariableStoreTypeMax
; Type
++) {
553 VariableStoreHeader
= GetVariableStore (Type
, &IndexTable
);
554 Status
= FindVariableEx (
561 if (!EFI_ERROR (Status
)) {
566 return EFI_NOT_FOUND
;
570 This service retrieves a variable's value using its name and GUID.
572 Read the specified variable from the UEFI variable store. If the Data
573 buffer is too small to hold the contents of the variable, the error
574 EFI_BUFFER_TOO_SMALL is returned and DataSize is set to the required buffer
575 size to obtain the data.
577 @param This A pointer to this instance of the EFI_PEI_READ_ONLY_VARIABLE2_PPI.
578 @param VariableName A pointer to a null-terminated string that is the variable's name.
579 @param VariableGuid A pointer to an EFI_GUID that is the variable's GUID. The combination of
580 VariableGuid and VariableName must be unique.
581 @param Attributes If non-NULL, on return, points to the variable's attributes.
582 @param DataSize On entry, points to the size in bytes of the Data buffer.
583 On return, points to the size of the data returned in Data.
584 @param Data Points to the buffer which will hold the returned variable value.
586 @retval EFI_SUCCESS The variable was read successfully.
587 @retval EFI_NOT_FOUND The variable could not be found.
588 @retval EFI_BUFFER_TOO_SMALL The DataSize is too small for the resulting data.
589 DataSize is updated with the size required for
590 the specified variable.
591 @retval EFI_INVALID_PARAMETER VariableName, VariableGuid, DataSize or Data is NULL.
592 @retval EFI_DEVICE_ERROR The variable could not be retrieved because of a device error.
598 IN CONST EFI_PEI_READ_ONLY_VARIABLE2_PPI
*This
,
599 IN CONST CHAR16
*VariableName
,
600 IN CONST EFI_GUID
*VariableGuid
,
601 OUT UINT32
*Attributes
,
602 IN OUT UINTN
*DataSize
,
606 VARIABLE_POINTER_TRACK Variable
;
610 if (VariableName
== NULL
|| VariableGuid
== NULL
|| DataSize
== NULL
) {
611 return EFI_INVALID_PARAMETER
;
615 // Find existing variable
617 Status
= FindVariable (VariableName
, VariableGuid
, &Variable
);
618 if (EFI_ERROR (Status
)) {
624 VarDataSize
= DataSizeOfVariable (Variable
.CurrPtr
);
625 if (*DataSize
>= VarDataSize
) {
627 return EFI_INVALID_PARAMETER
;
630 CopyMem (Data
, GetVariableDataPtr (Variable
.CurrPtr
), VarDataSize
);
632 if (Attributes
!= NULL
) {
633 *Attributes
= Variable
.CurrPtr
->Attributes
;
636 *DataSize
= VarDataSize
;
639 *DataSize
= VarDataSize
;
640 return EFI_BUFFER_TOO_SMALL
;
645 Return the next variable name and GUID.
647 This function is called multiple times to retrieve the VariableName
648 and VariableGuid of all variables currently available in the system.
649 On each call, the previous results are passed into the interface,
650 and, on return, the interface returns the data for the next
651 interface. When the entire variable list has been returned,
652 EFI_NOT_FOUND is returned.
654 @param This A pointer to this instance of the EFI_PEI_READ_ONLY_VARIABLE2_PPI.
656 @param VariableNameSize On entry, points to the size of the buffer pointed to by VariableName.
657 On return, the size of the variable name buffer.
658 @param VariableName On entry, a pointer to a null-terminated string that is the variable's name.
659 On return, points to the next variable's null-terminated name string.
660 @param VariableGuid On entry, a pointer to an EFI_GUID that is the variable's GUID.
661 On return, a pointer to the next variable's GUID.
663 @retval EFI_SUCCESS The variable was read successfully.
664 @retval EFI_NOT_FOUND The variable could not be found.
665 @retval EFI_BUFFER_TOO_SMALL The VariableNameSize is too small for the resulting
666 data. VariableNameSize is updated with the size
667 required for the specified variable.
668 @retval EFI_INVALID_PARAMETER VariableName, VariableGuid or
669 VariableNameSize is NULL.
670 @retval EFI_DEVICE_ERROR The variable could not be retrieved because of a device error.
675 PeiGetNextVariableName (
676 IN CONST EFI_PEI_READ_ONLY_VARIABLE2_PPI
*This
,
677 IN OUT UINTN
*VariableNameSize
,
678 IN OUT CHAR16
*VariableName
,
679 IN OUT EFI_GUID
*VariableGuid
682 VARIABLE_STORE_TYPE Type
;
683 VARIABLE_POINTER_TRACK Variable
;
684 VARIABLE_POINTER_TRACK VariableInHob
;
687 VARIABLE_STORE_HEADER
*VariableStoreHeader
[VariableStoreTypeMax
];
689 if (VariableName
== NULL
|| VariableGuid
== NULL
|| VariableNameSize
== NULL
) {
690 return EFI_INVALID_PARAMETER
;
693 Status
= FindVariable (VariableName
, VariableGuid
, &Variable
);
694 if (Variable
.CurrPtr
== NULL
|| Status
!= EFI_SUCCESS
) {
698 if (VariableName
[0] != 0) {
700 // If variable name is not NULL, get next variable
702 Variable
.CurrPtr
= GetNextVariablePtr (Variable
.CurrPtr
);
705 VariableStoreHeader
[VariableStoreTypeHob
] = GetVariableStore (VariableStoreTypeHob
, NULL
);
706 VariableStoreHeader
[VariableStoreTypeNv
] = GetVariableStore (VariableStoreTypeNv
, NULL
);
710 // Switch from HOB to Non-Volatile.
712 while ((Variable
.CurrPtr
>= Variable
.EndPtr
) ||
713 (Variable
.CurrPtr
== NULL
) ||
714 !IsValidVariableHeader (Variable
.CurrPtr
)
717 // Find current storage index
719 for (Type
= (VARIABLE_STORE_TYPE
) 0; Type
< VariableStoreTypeMax
; Type
++) {
720 if ((VariableStoreHeader
[Type
] != NULL
) && (Variable
.StartPtr
== GetStartPointer (VariableStoreHeader
[Type
]))) {
724 ASSERT (Type
< VariableStoreTypeMax
);
726 // Switch to next storage
728 for (Type
++; Type
< VariableStoreTypeMax
; Type
++) {
729 if (VariableStoreHeader
[Type
] != NULL
) {
734 // Capture the case that
735 // 1. current storage is the last one, or
736 // 2. no further storage
738 if (Type
== VariableStoreTypeMax
) {
739 return EFI_NOT_FOUND
;
741 Variable
.StartPtr
= GetStartPointer (VariableStoreHeader
[Type
]);
742 Variable
.EndPtr
= GetEndPointer (VariableStoreHeader
[Type
]);
743 Variable
.CurrPtr
= Variable
.StartPtr
;
746 if (Variable
.CurrPtr
->State
== VAR_ADDED
) {
749 // Don't return NV variable when HOB overrides it
751 if ((VariableStoreHeader
[VariableStoreTypeHob
] != NULL
) && (VariableStoreHeader
[VariableStoreTypeNv
] != NULL
) &&
752 (Variable
.StartPtr
== GetStartPointer (VariableStoreHeader
[VariableStoreTypeNv
]))
754 Status
= FindVariableEx (
755 VariableStoreHeader
[VariableStoreTypeHob
],
757 GetVariableNamePtr (Variable
.CurrPtr
),
758 &Variable
.CurrPtr
->VendorGuid
,
761 if (!EFI_ERROR (Status
)) {
762 Variable
.CurrPtr
= GetNextVariablePtr (Variable
.CurrPtr
);
767 VarNameSize
= NameSizeOfVariable (Variable
.CurrPtr
);
768 ASSERT (VarNameSize
!= 0);
770 if (VarNameSize
<= *VariableNameSize
) {
771 CopyMem (VariableName
, GetVariableNamePtr (Variable
.CurrPtr
), VarNameSize
);
773 CopyMem (VariableGuid
, &Variable
.CurrPtr
->VendorGuid
, sizeof (EFI_GUID
));
775 Status
= EFI_SUCCESS
;
777 Status
= EFI_BUFFER_TOO_SMALL
;
780 *VariableNameSize
= VarNameSize
;
786 Variable
.CurrPtr
= GetNextVariablePtr (Variable
.CurrPtr
);