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 - 2008 Intel Corporation. <BR>
7 All rights reserved. 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
,
35 EFI_GUID mEfiVariableIndexTableGuid
= EFI_VARIABLE_INDEX_TABLE_GUID
;
39 Provide the functionality of the variable services.
41 @param FileHandle Handle of the file being invoked.
42 Type EFI_PEI_FILE_HANDLE is defined in FfsFindNextFile().
43 @param PeiServices General purpose services available to every PEIM.
45 @retval EFI_SUCCESS If the interface could be successfully installed
46 @retval Others Returned from PeiServicesInstallPpi()
51 PeimInitializeVariableServices (
52 IN EFI_PEI_FILE_HANDLE FileHandle
,
53 IN CONST EFI_PEI_SERVICES
**PeiServices
56 EFI_BOOT_MODE BootMode
;
60 // Check if this is recovery boot path. If no, publish the variable access capability
61 // to other modules. If yes, the content of variable area is not reliable. Therefore,
62 // in this case we should not provide variable service to other pei modules.
64 Status
= (*PeiServices
)->GetBootMode (PeiServices
, &BootMode
);
65 ASSERT_EFI_ERROR (Status
);
67 if (BootMode
== BOOT_IN_RECOVERY_MODE
) {
68 return EFI_UNSUPPORTED
;
71 return PeiServicesInstallPpi (&mPpiListVariable
);
77 Gets the pointer to the first variable header in given variable store area.
79 @param VarStoreHeader Pointer to the Variable Store Header.
81 @return Pointer to the first variable header
86 IN VARIABLE_STORE_HEADER
*VarStoreHeader
90 // The end of variable store
92 return (VARIABLE_HEADER
*) HEADER_ALIGN (VarStoreHeader
+ 1);
97 This code gets the pointer to the last variable memory pointer byte.
99 @param VarStoreHeader Pointer to the Variable Store Header.
101 @return VARIABLE_HEADER* pointer to last unavailable Variable Header.
106 IN VARIABLE_STORE_HEADER
*VarStoreHeader
110 // The end of variable store
112 return (VARIABLE_HEADER
*) HEADER_ALIGN ((UINTN
) VarStoreHeader
+ VarStoreHeader
->Size
);
117 This code checks if variable header is valid or not.
119 @param Variable Pointer to the Variable Header.
121 @retval TRUE Variable header is valid.
122 @retval FALSE Variable header is not valid.
126 IsValidVariableHeader (
127 IN VARIABLE_HEADER
*Variable
130 if (Variable
== NULL
|| Variable
->StartId
!= VARIABLE_DATA
) {
139 This code gets the size of name of variable.
141 @param Variable Pointer to the Variable Header.
143 @return Size of variable in bytes in type UINTN.
148 IN VARIABLE_HEADER
*Variable
151 if (Variable
->State
== (UINT8
) (-1) ||
152 Variable
->DataSize
== (UINT32
) (-1) ||
153 Variable
->NameSize
== (UINT32
) (-1) ||
154 Variable
->Attributes
== (UINT32
) (-1)) {
157 return (UINTN
) Variable
->NameSize
;
162 This code gets the size of data of variable.
164 @param Variable Pointer to the Variable Header.
166 @return Size of variable in bytes in type UINTN.
171 IN VARIABLE_HEADER
*Variable
174 if (Variable
->State
== (UINT8
) (-1) ||
175 Variable
->DataSize
== (UINT32
) (-1) ||
176 Variable
->NameSize
== (UINT32
) (-1) ||
177 Variable
->Attributes
== (UINT32
) (-1)) {
180 return (UINTN
) Variable
->DataSize
;
184 This code gets the pointer to the variable name.
186 @param Variable Pointer to the Variable Header.
188 @return A CHAR16* pointer to Variable Name.
193 IN VARIABLE_HEADER
*Variable
197 return (CHAR16
*) (Variable
+ 1);
202 This code gets the pointer to the variable data.
204 @param Variable Pointer to the Variable Header.
206 @return A UINT8* pointer to Variable Data.
211 IN VARIABLE_HEADER
*Variable
217 // Be careful about pad size for alignment
219 Value
= (UINTN
) GetVariableNamePtr (Variable
);
220 Value
+= NameSizeOfVariable (Variable
);
221 Value
+= GET_PAD_SIZE (NameSizeOfVariable (Variable
));
223 return (UINT8
*) Value
;
228 This code gets the pointer to the next variable header.
230 @param Variable Pointer to the Variable Header.
232 @return A VARIABLE_HEADER* pointer to next variable header.
237 IN VARIABLE_HEADER
*Variable
242 if (!IsValidVariableHeader (Variable
)) {
246 Value
= (UINTN
) GetVariableDataPtr (Variable
);
247 Value
+= DataSizeOfVariable (Variable
);
248 Value
+= GET_PAD_SIZE (DataSizeOfVariable (Variable
));
251 // Be careful about pad size for alignment
253 return (VARIABLE_HEADER
*) HEADER_ALIGN (Value
);
257 This code gets the pointer to the variable name.
259 @param VarStoreHeader Pointer to the Variable Store Header.
261 @retval EfiRaw Variable store is raw
262 @retval EfiValid Variable store is valid
263 @retval EfiInvalid Variable store is invalid
266 VARIABLE_STORE_STATUS
267 GetVariableStoreStatus (
268 IN VARIABLE_STORE_HEADER
*VarStoreHeader
272 if (CompareGuid (&VarStoreHeader
->Signature
, &gEfiVariableGuid
) &&
273 VarStoreHeader
->Format
== VARIABLE_STORE_FORMATTED
&&
274 VarStoreHeader
->State
== VARIABLE_STORE_HEALTHY
280 if (((UINT32
*)(&VarStoreHeader
->Signature
))[0] == 0xffffffff &&
281 ((UINT32
*)(&VarStoreHeader
->Signature
))[1] == 0xffffffff &&
282 ((UINT32
*)(&VarStoreHeader
->Signature
))[2] == 0xffffffff &&
283 ((UINT32
*)(&VarStoreHeader
->Signature
))[3] == 0xffffffff &&
284 VarStoreHeader
->Size
== 0xffffffff &&
285 VarStoreHeader
->Format
== 0xff &&
286 VarStoreHeader
->State
== 0xff
297 This function compares a variable with variable entries in database.
299 @param Variable Pointer to the variable in our database
300 @param VariableName Name of the variable to compare to 'Variable'
301 @param VendorGuid GUID of the variable to compare to 'Variable'
302 @param PtrTrack Variable Track Pointer structure that contains Variable Information.
304 @retval EFI_SUCCESS Found match variable
305 @retval EFI_NOT_FOUND Variable not found
309 CompareWithValidVariable (
310 IN VARIABLE_HEADER
*Variable
,
311 IN CONST CHAR16
*VariableName
,
312 IN CONST EFI_GUID
*VendorGuid
,
313 OUT VARIABLE_POINTER_TRACK
*PtrTrack
318 if (VariableName
[0] == 0) {
319 PtrTrack
->CurrPtr
= Variable
;
323 // Don't use CompareGuid function here for performance reasons.
324 // Instead we compare the GUID a UINT32 at a time and branch
325 // on the first failed comparison.
327 if ((((INT32
*) VendorGuid
)[0] == ((INT32
*) &Variable
->VendorGuid
)[0]) &&
328 (((INT32
*) VendorGuid
)[1] == ((INT32
*) &Variable
->VendorGuid
)[1]) &&
329 (((INT32
*) VendorGuid
)[2] == ((INT32
*) &Variable
->VendorGuid
)[2]) &&
330 (((INT32
*) VendorGuid
)[3] == ((INT32
*) &Variable
->VendorGuid
)[3])
332 ASSERT (NameSizeOfVariable (Variable
) != 0);
333 Point
= (VOID
*) GetVariableNamePtr (Variable
);
334 if (CompareMem (VariableName
, Point
, NameSizeOfVariable (Variable
)) == 0) {
335 PtrTrack
->CurrPtr
= Variable
;
341 return EFI_NOT_FOUND
;
346 This code finds variable in storage blocks (Non-Volatile).
348 @param PeiServices General purpose services available to every PEIM.
349 @param VariableName Name of the variable to be found
350 @param VendorGuid Vendor GUID to be found.
351 @param PtrTrack Variable Track Pointer structure that contains Variable Information.
353 @retval EFI_SUCCESS Variable found successfully
354 @retval EFI_NOT_FOUND Variable not found
355 @retval EFI_INVALID_PARAMETER Invalid variable name
360 IN CONST EFI_PEI_SERVICES
**PeiServices
,
361 IN CONST CHAR16
*VariableName
,
362 IN CONST EFI_GUID
*VendorGuid
,
363 OUT VARIABLE_POINTER_TRACK
*PtrTrack
366 EFI_HOB_GUID_TYPE
*GuidHob
;
367 VARIABLE_STORE_HEADER
*VariableStoreHeader
;
368 VARIABLE_HEADER
*Variable
;
369 VARIABLE_HEADER
*MaxIndex
;
370 VARIABLE_INDEX_TABLE
*IndexTable
;
374 if (VariableName
[0] != 0 && VendorGuid
== NULL
) {
375 return EFI_INVALID_PARAMETER
;
378 // No Variable Address equals zero, so 0 as initial value is safe.
382 GuidHob
= GetFirstGuidHob (&mEfiVariableIndexTableGuid
);
383 if (GuidHob
== NULL
) {
384 IndexTable
= BuildGuidHob (&mEfiVariableIndexTableGuid
, sizeof (VARIABLE_INDEX_TABLE
));
385 IndexTable
->Length
= 0;
386 IndexTable
->StartPtr
= NULL
;
387 IndexTable
->EndPtr
= NULL
;
388 IndexTable
->GoneThrough
= 0;
390 IndexTable
= GET_GUID_HOB_DATA (GuidHob
);
391 for (Count
= 0; Count
< IndexTable
->Length
; Count
++) {
392 MaxIndex
= GetVariableByIndex (IndexTable
, Count
);
394 if (CompareWithValidVariable (MaxIndex
, VariableName
, VendorGuid
, PtrTrack
) == EFI_SUCCESS
) {
395 PtrTrack
->StartPtr
= IndexTable
->StartPtr
;
396 PtrTrack
->EndPtr
= IndexTable
->EndPtr
;
402 if (IndexTable
->GoneThrough
!= 0) {
403 return EFI_NOT_FOUND
;
407 // If not found in HOB, then let's start from the MaxIndex we've found.
409 if (MaxIndex
!= NULL
) {
410 Variable
= GetNextVariablePtr (MaxIndex
);
412 if ((IndexTable
->StartPtr
!= NULL
) || (IndexTable
->EndPtr
!= NULL
)) {
413 Variable
= IndexTable
->StartPtr
;
415 VariableBase
= (UINT8
*) (UINTN
) PcdGet32 (PcdFlashNvStorageVariableBase
);
416 VariableStoreHeader
= (VARIABLE_STORE_HEADER
*) (VariableBase
+ \
417 ((EFI_FIRMWARE_VOLUME_HEADER
*) (VariableBase
)) -> HeaderLength
);
419 if (GetVariableStoreStatus (VariableStoreHeader
) != EfiValid
) {
420 return EFI_UNSUPPORTED
;
423 if (~VariableStoreHeader
->Size
== 0) {
424 return EFI_NOT_FOUND
;
427 // Find the variable by walk through non-volatile variable store
429 IndexTable
->StartPtr
= GetStartPointer (VariableStoreHeader
);
430 IndexTable
->EndPtr
= GetEndPointer (VariableStoreHeader
);
433 // Start Pointers for the variable.
434 // Actual Data Pointer where data can be written.
436 Variable
= IndexTable
->StartPtr
;
440 // Find the variable by walk through non-volatile variable store
442 PtrTrack
->StartPtr
= IndexTable
->StartPtr
;
443 PtrTrack
->EndPtr
= IndexTable
->EndPtr
;
445 while (IsValidVariableHeader (Variable
) && (Variable
<= IndexTable
->EndPtr
)) {
446 if (Variable
->State
== VAR_ADDED
) {
448 // Record Variable in VariableIndex HOB
450 VariableIndexTableUpdate (IndexTable
, Variable
);
452 if (CompareWithValidVariable (Variable
, VariableName
, VendorGuid
, PtrTrack
) == EFI_SUCCESS
) {
457 Variable
= GetNextVariablePtr (Variable
);
460 // If gone through the VariableStore, that means we never find in Firmware any more.
462 if (IndexTable
->Length
< VARIABLE_INDEX_TABLE_VOLUME
) {
463 IndexTable
->GoneThrough
= 1;
466 PtrTrack
->CurrPtr
= NULL
;
468 return EFI_NOT_FOUND
;
472 This service retrieves a variable's value using its name and GUID.
474 Read the specified variable from the UEFI variable store. If the Data
475 buffer is too small to hold the contents of the variable, the error
476 EFI_BUFFER_TOO_SMALL is returned and DataSize is set to the required buffer
477 size to obtain the data.
479 @param This A pointer to this instance of the EFI_PEI_READ_ONLY_VARIABLE2_PPI.
480 @param VariableName A pointer to a null-terminated string that is the variable's name.
481 @param VariableGuid A pointer to an EFI_GUID that is the variable's GUID. The combination of
482 VariableGuid and VariableName must be unique.
483 @param Attributes If non-NULL, on return, points to the variable's attributes.
484 @param DataSize On entry, points to the size in bytes of the Data buffer.
485 On return, points to the size of the data returned in Data.
486 @param Data Points to the buffer which will hold the returned variable value.
488 @retval EFI_SUCCESS The variable was read successfully.
489 @retval EFI_NOT_FOUND The variable could not be found.
490 @retval EFI_BUFFER_TOO_SMALL The DataSize is too small for the resulting data.
491 DataSize is updated with the size required for
492 the specified variable.
493 @retval EFI_INVALID_PARAMETER VariableName, VariableGuid, DataSize or Data is NULL.
494 @retval EFI_DEVICE_ERROR The variable could not be retrieved because of a device error.
500 IN CONST EFI_PEI_READ_ONLY_VARIABLE2_PPI
*This
,
501 IN CONST CHAR16
*VariableName
,
502 IN CONST EFI_GUID
*VariableGuid
,
503 OUT UINT32
*Attributes
,
504 IN OUT UINTN
*DataSize
,
508 VARIABLE_POINTER_TRACK Variable
;
511 CONST EFI_PEI_SERVICES
**PeiServices
;
513 PeiServices
= GetPeiServicesTablePointer ();
514 if (VariableName
== NULL
|| VariableGuid
== NULL
|| DataSize
== NULL
) {
515 return EFI_INVALID_PARAMETER
;
518 // Find existing variable
520 Status
= FindVariable (PeiServices
, VariableName
, VariableGuid
, &Variable
);
521 if (Variable
.CurrPtr
== NULL
|| Status
!= EFI_SUCCESS
) {
527 VarDataSize
= DataSizeOfVariable (Variable
.CurrPtr
);
528 if (*DataSize
>= VarDataSize
) {
530 return EFI_INVALID_PARAMETER
;
533 CopyMem (Data
, GetVariableDataPtr (Variable
.CurrPtr
), VarDataSize
);
535 if (Attributes
!= NULL
) {
536 *Attributes
= Variable
.CurrPtr
->Attributes
;
539 *DataSize
= VarDataSize
;
542 *DataSize
= VarDataSize
;
543 return EFI_BUFFER_TOO_SMALL
;
548 Return the next variable name and GUID.
550 This function is called multiple times to retrieve the VariableName
551 and VariableGuid of all variables currently available in the system.
552 On each call, the previous results are passed into the interface,
553 and, on return, the interface returns the data for the next
554 interface. When the entire variable list has been returned,
555 EFI_NOT_FOUND is returned.
557 @param This A pointer to this instance of the EFI_PEI_READ_ONLY_VARIABLE2_PPI.
559 @param VariableNameSize On entry, points to the size of the buffer pointed to by VariableName.
560 @param VariableName On entry, a pointer to a null-terminated string that is the variable's name.
561 On return, points to the next variable's null-terminated name string.
562 @param VariableGuid On entry, a pointer to an UEFI _GUID that is the variable's GUID.
563 On return, a pointer to the next variable's GUID.
565 @retval EFI_SUCCESS The variable was read successfully.
566 @retval EFI_NOT_FOUND The variable could not be found.
567 @retval EFI_BUFFER_TOO_SMALL The VariableNameSize is too small for the resulting
568 data. VariableNameSize is updated with the size
569 required for the specified variable.
570 @retval EFI_INVALID_PARAMETER VariableName, VariableGuid or
571 VariableNameSize is NULL.
572 @retval EFI_DEVICE_ERROR The variable could not be retrieved because of a device error.
577 PeiGetNextVariableName (
578 IN CONST EFI_PEI_READ_ONLY_VARIABLE2_PPI
*This
,
579 IN OUT UINTN
*VariableNameSize
,
580 IN OUT CHAR16
*VariableName
,
581 IN OUT EFI_GUID
*VariableGuid
584 VARIABLE_POINTER_TRACK Variable
;
587 CONST EFI_PEI_SERVICES
**PeiServices
;
589 PeiServices
= GetPeiServicesTablePointer ();
590 if (VariableName
== NULL
|| VariableGuid
== NULL
|| VariableNameSize
== NULL
) {
591 return EFI_INVALID_PARAMETER
;
594 Status
= FindVariable (PeiServices
, VariableName
, VariableGuid
, &Variable
);
595 if (Variable
.CurrPtr
== NULL
|| Status
!= EFI_SUCCESS
) {
599 if (VariableName
[0] != 0) {
601 // If variable name is not NULL, get next variable
603 Variable
.CurrPtr
= GetNextVariablePtr (Variable
.CurrPtr
);
606 while (!(Variable
.CurrPtr
>= Variable
.EndPtr
|| Variable
.CurrPtr
== NULL
)) {
607 if (IsValidVariableHeader (Variable
.CurrPtr
)) {
608 if (Variable
.CurrPtr
->State
== VAR_ADDED
) {
609 ASSERT (NameSizeOfVariable (Variable
.CurrPtr
) != 0);
611 VarNameSize
= (UINTN
) NameSizeOfVariable (Variable
.CurrPtr
);
612 if (VarNameSize
<= *VariableNameSize
) {
613 CopyMem (VariableName
, GetVariableNamePtr (Variable
.CurrPtr
), VarNameSize
);
615 CopyMem (VariableGuid
, &Variable
.CurrPtr
->VendorGuid
, sizeof (EFI_GUID
));
617 Status
= EFI_SUCCESS
;
619 Status
= EFI_BUFFER_TOO_SMALL
;
622 *VariableNameSize
= VarNameSize
;
628 Variable
.CurrPtr
= GetNextVariablePtr (Variable
.CurrPtr
);
635 return EFI_NOT_FOUND
;