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
271 if (VarStoreHeader
->Signature
== VARIABLE_STORE_SIGNATURE
&&
272 VarStoreHeader
->Format
== VARIABLE_STORE_FORMATTED
&&
273 VarStoreHeader
->State
== VARIABLE_STORE_HEALTHY
279 if (VarStoreHeader
->Signature
== 0xffffffff &&
280 VarStoreHeader
->Size
== 0xffffffff &&
281 VarStoreHeader
->Format
== 0xff &&
282 VarStoreHeader
->State
== 0xff
293 This function compares a variable with variable entries in database.
295 @param Variable Pointer to the variable in our database
296 @param VariableName Name of the variable to compare to 'Variable'
297 @param VendorGuid GUID of the variable to compare to 'Variable'
298 @param PtrTrack Variable Track Pointer structure that contains Variable Information.
300 @retval EFI_SUCCESS Found match variable
301 @retval EFI_NOT_FOUND Variable not found
305 CompareWithValidVariable (
306 IN VARIABLE_HEADER
*Variable
,
307 IN CONST CHAR16
*VariableName
,
308 IN CONST EFI_GUID
*VendorGuid
,
309 OUT VARIABLE_POINTER_TRACK
*PtrTrack
314 if (VariableName
[0] == 0) {
315 PtrTrack
->CurrPtr
= Variable
;
319 // Don't use CompareGuid function here for performance reasons.
320 // Instead we compare the GUID a UINT32 at a time and branch
321 // on the first failed comparison.
323 if ((((INT32
*) VendorGuid
)[0] == ((INT32
*) &Variable
->VendorGuid
)[0]) &&
324 (((INT32
*) VendorGuid
)[1] == ((INT32
*) &Variable
->VendorGuid
)[1]) &&
325 (((INT32
*) VendorGuid
)[2] == ((INT32
*) &Variable
->VendorGuid
)[2]) &&
326 (((INT32
*) VendorGuid
)[3] == ((INT32
*) &Variable
->VendorGuid
)[3])
328 ASSERT (NameSizeOfVariable (Variable
) != 0);
329 Point
= (VOID
*) GetVariableNamePtr (Variable
);
330 if (CompareMem (VariableName
, Point
, NameSizeOfVariable (Variable
)) == 0) {
331 PtrTrack
->CurrPtr
= Variable
;
337 return EFI_NOT_FOUND
;
342 This code finds variable in storage blocks (Non-Volatile).
344 @param PeiServices General purpose services available to every PEIM.
345 @param VariableName Name of the variable to be found
346 @param VendorGuid Vendor GUID to be found.
347 @param PtrTrack Variable Track Pointer structure that contains Variable Information.
349 @retval EFI_SUCCESS Variable found successfully
350 @retval EFI_NOT_FOUND Variable not found
351 @retval EFI_INVALID_PARAMETER Invalid variable name
356 IN CONST EFI_PEI_SERVICES
**PeiServices
,
357 IN CONST CHAR16
*VariableName
,
358 IN CONST EFI_GUID
*VendorGuid
,
359 OUT VARIABLE_POINTER_TRACK
*PtrTrack
362 EFI_HOB_GUID_TYPE
*GuidHob
;
363 VARIABLE_STORE_HEADER
*VariableStoreHeader
;
364 VARIABLE_HEADER
*Variable
;
365 VARIABLE_HEADER
*MaxIndex
;
366 VARIABLE_INDEX_TABLE
*IndexTable
;
370 if (VariableName
[0] != 0 && VendorGuid
== NULL
) {
371 return EFI_INVALID_PARAMETER
;
374 // No Variable Address equals zero, so 0 as initial value is safe.
378 GuidHob
= GetFirstGuidHob (&mEfiVariableIndexTableGuid
);
379 if (GuidHob
== NULL
) {
380 IndexTable
= BuildGuidHob (&mEfiVariableIndexTableGuid
, sizeof (VARIABLE_INDEX_TABLE
));
381 IndexTable
->Length
= 0;
382 IndexTable
->StartPtr
= NULL
;
383 IndexTable
->EndPtr
= NULL
;
384 IndexTable
->GoneThrough
= 0;
386 IndexTable
= GET_GUID_HOB_DATA (GuidHob
);
387 for (Count
= 0; Count
< IndexTable
->Length
; Count
++) {
388 MaxIndex
= GetVariableByIndex (IndexTable
, Count
);
390 if (CompareWithValidVariable (MaxIndex
, VariableName
, VendorGuid
, PtrTrack
) == EFI_SUCCESS
) {
391 PtrTrack
->StartPtr
= IndexTable
->StartPtr
;
392 PtrTrack
->EndPtr
= IndexTable
->EndPtr
;
398 if (IndexTable
->GoneThrough
!= 0) {
399 return EFI_NOT_FOUND
;
403 // If not found in HOB, then let's start from the MaxIndex we've found.
405 if (MaxIndex
!= NULL
) {
406 Variable
= GetNextVariablePtr (MaxIndex
);
408 if ((IndexTable
->StartPtr
!= NULL
) || (IndexTable
->EndPtr
!= NULL
)) {
409 Variable
= IndexTable
->StartPtr
;
411 VariableBase
= (UINT8
*) (UINTN
) PcdGet32 (PcdFlashNvStorageVariableBase
);
412 VariableStoreHeader
= (VARIABLE_STORE_HEADER
*) (VariableBase
+ \
413 ((EFI_FIRMWARE_VOLUME_HEADER
*) (VariableBase
)) -> HeaderLength
);
415 if (GetVariableStoreStatus (VariableStoreHeader
) != EfiValid
) {
416 return EFI_UNSUPPORTED
;
419 if (~VariableStoreHeader
->Size
== 0) {
420 return EFI_NOT_FOUND
;
423 // Find the variable by walk through non-volatile variable store
425 IndexTable
->StartPtr
= GetStartPointer (VariableStoreHeader
);
426 IndexTable
->EndPtr
= GetEndPointer (VariableStoreHeader
);
429 // Start Pointers for the variable.
430 // Actual Data Pointer where data can be written.
432 Variable
= IndexTable
->StartPtr
;
436 // Find the variable by walk through non-volatile variable store
438 PtrTrack
->StartPtr
= IndexTable
->StartPtr
;
439 PtrTrack
->EndPtr
= IndexTable
->EndPtr
;
441 while (IsValidVariableHeader (Variable
) && (Variable
<= IndexTable
->EndPtr
)) {
442 if (Variable
->State
== VAR_ADDED
) {
444 // Record Variable in VariableIndex HOB
446 if (IndexTable
->Length
< VARIABLE_INDEX_TABLE_VOLUME
) {
447 VariableIndexTableUpdate (IndexTable
, Variable
);
450 if (CompareWithValidVariable (Variable
, VariableName
, VendorGuid
, PtrTrack
) == EFI_SUCCESS
) {
455 Variable
= GetNextVariablePtr (Variable
);
458 // If gone through the VariableStore, that means we never find in Firmware any more.
460 if (IndexTable
->Length
< VARIABLE_INDEX_TABLE_VOLUME
) {
461 IndexTable
->GoneThrough
= 1;
464 PtrTrack
->CurrPtr
= NULL
;
466 return EFI_NOT_FOUND
;
470 This service retrieves a variable's value using its name and GUID.
472 Read the specified variable from the UEFI variable store. If the Data
473 buffer is too small to hold the contents of the variable, the error
474 EFI_BUFFER_TOO_SMALL is returned and DataSize is set to the required buffer
475 size to obtain the data.
477 @param This A pointer to this instance of the EFI_PEI_READ_ONLY_VARIABLE2_PPI.
478 @param VariableName A pointer to a null-terminated string that is the variable's name.
479 @param VariableGuid A pointer to an EFI_GUID that is the variable's GUID. The combination of
480 VariableGuid and VariableName must be unique.
481 @param Attributes If non-NULL, on return, points to the variable's attributes.
482 @param DataSize On entry, points to the size in bytes of the Data buffer.
483 On return, points to the size of the data returned in Data.
484 @param Data Points to the buffer which will hold the returned variable value.
486 @retval EFI_SUCCESS The variable was read successfully.
487 @retval EFI_NOT_FOUND The variable could not be found.
488 @retval EFI_BUFFER_TOO_SMALL The DataSize is too small for the resulting data.
489 DataSize is updated with the size required for
490 the specified variable.
491 @retval EFI_INVALID_PARAMETER VariableName, VariableGuid, DataSize or Data is NULL.
492 @retval EFI_DEVICE_ERROR The variable could not be retrieved because of a device error.
498 IN CONST EFI_PEI_READ_ONLY_VARIABLE2_PPI
*This
,
499 IN CONST CHAR16
*VariableName
,
500 IN CONST EFI_GUID
*VariableGuid
,
501 OUT UINT32
*Attributes
,
502 IN OUT UINTN
*DataSize
,
506 VARIABLE_POINTER_TRACK Variable
;
509 CONST EFI_PEI_SERVICES
**PeiServices
;
511 PeiServices
= GetPeiServicesTablePointer ();
512 if (VariableName
== NULL
|| VariableGuid
== NULL
|| DataSize
== NULL
) {
513 return EFI_INVALID_PARAMETER
;
516 // Find existing variable
518 Status
= FindVariable (PeiServices
, VariableName
, VariableGuid
, &Variable
);
519 if (Variable
.CurrPtr
== NULL
|| Status
!= EFI_SUCCESS
) {
525 VarDataSize
= DataSizeOfVariable (Variable
.CurrPtr
);
526 if (*DataSize
>= VarDataSize
) {
528 return EFI_INVALID_PARAMETER
;
531 CopyMem (Data
, GetVariableDataPtr (Variable
.CurrPtr
), VarDataSize
);
533 if (Attributes
!= NULL
) {
534 *Attributes
= Variable
.CurrPtr
->Attributes
;
537 *DataSize
= VarDataSize
;
540 *DataSize
= VarDataSize
;
541 return EFI_BUFFER_TOO_SMALL
;
546 Return the next variable name and GUID.
548 This function is called multiple times to retrieve the VariableName
549 and VariableGuid of all variables currently available in the system.
550 On each call, the previous results are passed into the interface,
551 and, on return, the interface returns the data for the next
552 interface. When the entire variable list has been returned,
553 EFI_NOT_FOUND is returned.
555 @param This A pointer to this instance of the EFI_PEI_READ_ONLY_VARIABLE2_PPI.
557 @param VariableNameSize On entry, points to the size of the buffer pointed to by VariableName.
558 @param VariableName On entry, a pointer to a null-terminated string that is the variable's name.
559 On return, points to the next variable's null-terminated name string.
560 @param VariableGuid On entry, a pointer to an UEFI _GUID that is the variable's GUID.
561 On return, a pointer to the next variable's GUID.
563 @retval EFI_SUCCESS The variable was read successfully.
564 @retval EFI_NOT_FOUND The variable could not be found.
565 @retval EFI_BUFFER_TOO_SMALL The VariableNameSize is too small for the resulting
566 data. VariableNameSize is updated with the size
567 required for the specified variable.
568 @retval EFI_INVALID_PARAMETER VariableName, VariableGuid or
569 VariableNameSize is NULL.
570 @retval EFI_DEVICE_ERROR The variable could not be retrieved because of a device error.
575 PeiGetNextVariableName (
576 IN CONST EFI_PEI_READ_ONLY_VARIABLE2_PPI
*This
,
577 IN OUT UINTN
*VariableNameSize
,
578 IN OUT CHAR16
*VariableName
,
579 IN OUT EFI_GUID
*VariableGuid
582 VARIABLE_POINTER_TRACK Variable
;
585 CONST EFI_PEI_SERVICES
**PeiServices
;
587 PeiServices
= GetPeiServicesTablePointer ();
588 if (VariableName
== NULL
|| VariableGuid
== NULL
|| VariableNameSize
== NULL
) {
589 return EFI_INVALID_PARAMETER
;
592 Status
= FindVariable (PeiServices
, VariableName
, VariableGuid
, &Variable
);
593 if (Variable
.CurrPtr
== NULL
|| Status
!= EFI_SUCCESS
) {
597 if (VariableName
[0] != 0) {
599 // If variable name is not NULL, get next variable
601 Variable
.CurrPtr
= GetNextVariablePtr (Variable
.CurrPtr
);
604 while (!(Variable
.CurrPtr
>= Variable
.EndPtr
|| Variable
.CurrPtr
== NULL
)) {
605 if (IsValidVariableHeader (Variable
.CurrPtr
)) {
606 if (Variable
.CurrPtr
->State
== VAR_ADDED
) {
607 ASSERT (NameSizeOfVariable (Variable
.CurrPtr
) != 0);
609 VarNameSize
= (UINTN
) NameSizeOfVariable (Variable
.CurrPtr
);
610 if (VarNameSize
<= *VariableNameSize
) {
611 CopyMem (VariableName
, GetVariableNamePtr (Variable
.CurrPtr
), VarNameSize
);
613 CopyMem (VariableGuid
, &Variable
.CurrPtr
->VendorGuid
, sizeof (EFI_GUID
));
615 Status
= EFI_SUCCESS
;
617 Status
= EFI_BUFFER_TOO_SMALL
;
620 *VariableNameSize
= VarNameSize
;
626 Variable
.CurrPtr
= GetNextVariablePtr (Variable
.CurrPtr
);
633 return EFI_NOT_FOUND
;