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/*++
Copyright (c) 2006, Intel Corporation
All rights reserved. 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:
Variable.c
Abstract:
Framework PEIM to provide the Variable functionality
--*/
#include <Variable.h>
//
// Module globals
//
static EFI_PEI_READ_ONLY_VARIABLE_PPI mVariablePpi = {
PeiGetVariable,
PeiGetNextVariableName
};
static EFI_PEI_PPI_DESCRIPTOR mPpiListVariable = {
(EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
&gEfiPeiReadOnlyVariablePpiGuid,
&mVariablePpi
};
EFI_GUID gEfiVariableIndexTableGuid = EFI_VARIABLE_INDEX_TABLE_GUID;
EFI_STATUS
EFIAPI
PeimInitializeVariableServices (
IN EFI_FFS_FILE_HEADER *FfsHeader,
IN EFI_PEI_SERVICES **PeiServices
)
/*++
Routine Description:
Provide the functionality of the variable services.
Arguments:
FfsHeadher - The FFS file header
PeiServices - General purpose services available to every PEIM.
Returns:
Status - EFI_SUCCESS if the interface could be successfully
installed
--*/
{
//
// Publish the variable capability to other modules
//
return (**PeiServices).InstallPpi (PeiServices, &mPpiListVariable);
}
STATIC
VARIABLE_HEADER *
GetNextVariablePtr (
IN VARIABLE_HEADER *Variable
)
/*++
Routine Description:
This code checks if variable header is valid or not.
Arguments:
Variable Pointer to the Variable Header.
Returns:
TRUE Variable header is valid.
FALSE Variable header is not valid.
--*/
{
return (VARIABLE_HEADER *) ((UINTN) GET_VARIABLE_DATA_PTR (Variable) + Variable->DataSize + GET_PAD_SIZE (Variable->DataSize));
}
STATIC
BOOLEAN
EFIAPI
IsValidVariableHeader (
IN VARIABLE_HEADER *Variable
)
/*++
Routine Description:
This code checks if variable header is valid or not.
Arguments:
Variable Pointer to the Variable Header.
Returns:
TRUE Variable header is valid.
FALSE Variable header is not valid.
--*/
{
if (Variable == NULL ||
Variable->StartId != VARIABLE_DATA ||
(sizeof (VARIABLE_HEADER) + Variable->DataSize + Variable->NameSize) > MAX_VARIABLE_SIZE
) {
return FALSE;
}
return TRUE;
}
STATIC
VARIABLE_STORE_STATUS
EFIAPI
GetVariableStoreStatus (
IN VARIABLE_STORE_HEADER *VarStoreHeader
)
/*++
Routine Description:
This code gets the pointer to the variable name.
Arguments:
VarStoreHeader Pointer to the Variable Store Header.
Returns:
EfiRaw Variable store is raw
EfiValid Variable store is valid
EfiInvalid Variable store is invalid
--*/
{
if (VarStoreHeader->Signature == VARIABLE_STORE_SIGNATURE &&
VarStoreHeader->Format == VARIABLE_STORE_FORMATTED &&
VarStoreHeader->State == VARIABLE_STORE_HEALTHY
) {
return EfiValid;
}
if (VarStoreHeader->Signature == 0xffffffff &&
VarStoreHeader->Size == 0xffffffff &&
VarStoreHeader->Format == 0xff &&
VarStoreHeader->State == 0xff
) {
return EfiRaw;
} else {
return EfiInvalid;
}
}
STATIC
EFI_STATUS
CompareWithValidVariable (
IN VARIABLE_HEADER *Variable,
IN CHAR16 *VariableName,
IN EFI_GUID *VendorGuid,
OUT VARIABLE_POINTER_TRACK *PtrTrack
)
/*++
Routine Description:
This function compares a variable with variable entries in database
Arguments:
Variable - Pointer to the variable in our database
VariableName - Name of the variable to compare to 'Variable'
VendorGuid - GUID of the variable to compare to 'Variable'
PtrTrack - Variable Track Pointer structure that contains
Variable Information.
Returns:
EFI_SUCCESS - Found match variable
EFI_NOT_FOUND - Variable not found
--*/
{
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])
) {
if (!StrCmp (VariableName, GET_VARIABLE_NAME_PTR (Variable))) {
PtrTrack->CurrPtr = Variable;
return EFI_SUCCESS;
}
}
}
return EFI_NOT_FOUND;
}
STATIC
EFI_STATUS
EFIAPI
FindVariable (
IN EFI_PEI_SERVICES **PeiServices,
IN CHAR16 *VariableName,
IN EFI_GUID *VendorGuid,
OUT VARIABLE_POINTER_TRACK *PtrTrack
)
/*++
Routine Description:
This code finds variable in storage blocks (Non-Volatile)
Arguments:
PeiServices - General purpose services available to every PEIM.
VariableName - Name of the variable to be found
VendorGuid - Vendor GUID to be found.
PtrTrack - Variable Track Pointer structure that contains
Variable Information.
Returns:
EFI_SUCCESS - Variable found successfully
EFI_NOT_FOUND - Variable not found
EFI_INVALID_PARAMETER - Invalid variable name
--*/
{
EFI_HOB_GUID_TYPE *GuidHob;
VARIABLE_STORE_HEADER *VariableStoreHeader;
VARIABLE_HEADER *Variable;
VARIABLE_HEADER *MaxIndex;
VARIABLE_INDEX_TABLE *IndexTable;
UINT32 Count;
UINT8 *VariableBase;
if (VariableName != 0 && VendorGuid == NULL) {
return EFI_INVALID_PARAMETER;
}
//
// No Variable Address equals zero, so 0 as initial value is safe.
//
MaxIndex = 0;
GuidHob = GetFirstGuidHob (&gEfiVariableIndexTableGuid);
if (GuidHob == NULL) {
IndexTable = BuildGuidHob (&gEfiVariableIndexTableGuid, sizeof (VARIABLE_INDEX_TABLE));
IndexTable->Length = 0;
IndexTable->StartPtr = NULL;
IndexTable->EndPtr = NULL;
IndexTable->GoneThrough = 0;
} else {
IndexTable = GET_GUID_HOB_DATA (GuidHob);
for (Count = 0; Count < IndexTable->Length; Count++)
{
#if ALIGNMENT <= 1
MaxIndex = (VARIABLE_HEADER *) (UINTN) (IndexTable->Index[Count] + ((UINTN) IndexTable->StartPtr & 0xFFFF0000));
#else
#if ALIGNMENT >= 4
MaxIndex = (VARIABLE_HEADER *) (UINTN) ((((UINT32)IndexTable->Index[Count]) << 2) + ((UINT32)(UINTN)IndexTable->StartPtr & 0xFFFC0000) );
#endif
#endif
if (CompareWithValidVariable (MaxIndex, VariableName, VendorGuid, PtrTrack) == EFI_SUCCESS) {
PtrTrack->StartPtr = IndexTable->StartPtr;
PtrTrack->EndPtr = IndexTable->EndPtr;
return EFI_SUCCESS;
}
}
if (IndexTable->GoneThrough) {
return EFI_NOT_FOUND;
}
}
//
// If not found in HOB, then let's start from the MaxIndex we've found.
//
if (MaxIndex != NULL) {
Variable = GetNextVariablePtr (MaxIndex);
} else {
if (IndexTable->StartPtr || IndexTable->EndPtr) {
Variable = IndexTable->StartPtr;
} else {
VariableBase = (UINT8 *) (UINTN) PcdGet32 (PcdFlashNvStorageVariableBase);
VariableStoreHeader = (VARIABLE_STORE_HEADER *) (VariableBase + \
((EFI_FIRMWARE_VOLUME_HEADER *) (VariableBase)) -> HeaderLength);
if (GetVariableStoreStatus (VariableStoreHeader) != EfiValid) {
return EFI_UNSUPPORTED;
}
if (~VariableStoreHeader->Size == 0) {
return EFI_NOT_FOUND;
}
//
// Find the variable by walk through non-volatile variable store
//
IndexTable->StartPtr = (VARIABLE_HEADER *) (VariableStoreHeader + 1);
IndexTable->EndPtr = (VARIABLE_HEADER *) ((UINTN) VariableStoreHeader + VariableStoreHeader->Size);
//
// Start Pointers for the variable.
// Actual Data Pointer where data can be written.
//
Variable = IndexTable->StartPtr;
}
}
//
// Find the variable by walk through non-volatile variable store
//
PtrTrack->StartPtr = IndexTable->StartPtr;
PtrTrack->EndPtr = IndexTable->EndPtr;
while (IsValidVariableHeader (Variable) && (Variable <= IndexTable->EndPtr)) {
if (Variable->State == VAR_ADDED) {
//
// Record Variable in VariableIndex HOB
//
if (IndexTable->Length < VARIABLE_INDEX_TABLE_VOLUME)
{
#if ALIGNMENT <= 1
IndexTable->Index[IndexTable->Length++] = (UINT16) (UINTN) Variable;
#else
#if ALIGNMENT >= 4
IndexTable->Index[IndexTable->Length++] = (UINT16) (((UINT32)(UINTN) Variable) >> 2);
#endif
#endif
}
if (CompareWithValidVariable (Variable, VariableName, VendorGuid, PtrTrack) == EFI_SUCCESS) {
return EFI_SUCCESS;
}
}
Variable = GetNextVariablePtr (Variable);
}
//
// If gone through the VariableStore, that means we never find in Firmware any more.
//
if (IndexTable->Length < VARIABLE_INDEX_TABLE_VOLUME) {
IndexTable->GoneThrough = 1;
}
PtrTrack->CurrPtr = NULL;
return EFI_NOT_FOUND;
}
EFI_STATUS
EFIAPI
PeiGetVariable (
IN EFI_PEI_SERVICES **PeiServices,
IN CHAR16 *VariableName,
IN EFI_GUID * VendorGuid,
OUT UINT32 *Attributes OPTIONAL,
IN OUT UINTN *DataSize,
OUT VOID *Data
)
/*++
Routine Description:
Provide the read variable functionality of the variable services.
Arguments:
PeiServices - General purpose services available to every PEIM.
VariableName - The variable name
VendorGuid - The vendor's GUID
Attributes - Pointer to the attribute
DataSize - Size of data
Data - Pointer to data
Returns:
EFI_SUCCESS - The interface could be successfully installed
EFI_NOT_FOUND - The variable could not be discovered
EFI_BUFFER_TOO_SMALL - The caller buffer is not large enough
--*/
{
VARIABLE_POINTER_TRACK Variable;
UINTN VarDataSize;
EFI_STATUS Status;
if (VariableName == NULL || VendorGuid == NULL) {
return EFI_INVALID_PARAMETER;
}
//
// Find existing variable
//
Status = FindVariable (PeiServices, VariableName, VendorGuid, &Variable);
if (Variable.CurrPtr == NULL || Status != EFI_SUCCESS) {
return Status;
}
//
// Get data size
//
VarDataSize = Variable.CurrPtr->DataSize;
if (*DataSize >= VarDataSize) {
(*PeiServices)->CopyMem (Data, GET_VARIABLE_DATA_PTR (Variable.CurrPtr), VarDataSize);
if (Attributes != NULL) {
*Attributes = Variable.CurrPtr->Attributes;
}
*DataSize = VarDataSize;
return EFI_SUCCESS;
} else {
*DataSize = VarDataSize;
return EFI_BUFFER_TOO_SMALL;
}
}
EFI_STATUS
EFIAPI
PeiGetNextVariableName (
IN EFI_PEI_SERVICES **PeiServices,
IN OUT UINTN *VariableNameSize,
IN OUT CHAR16 *VariableName,
IN OUT EFI_GUID *VendorGuid
)
/*++
Routine Description:
Provide the get next variable functionality of the variable services.
Arguments:
PeiServices - General purpose services available to every PEIM.
VariabvleNameSize - The variable name's size.
VariableName - A pointer to the variable's name.
VendorGuid - A pointer to the EFI_GUID structure.
VariableNameSize - Size of the variable name
VariableName - The variable name
VendorGuid - The vendor's GUID
Returns:
EFI_SUCCESS - The interface could be successfully installed
EFI_NOT_FOUND - The variable could not be discovered
--*/
{
VARIABLE_POINTER_TRACK Variable;
UINTN VarNameSize;
EFI_STATUS Status;
if (VariableName == NULL) {
return EFI_INVALID_PARAMETER;
}
Status = FindVariable (PeiServices, VariableName, VendorGuid, &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);
}
while (!(Variable.CurrPtr >= Variable.EndPtr || Variable.CurrPtr == NULL)) {
if (IsValidVariableHeader (Variable.CurrPtr)) {
if (Variable.CurrPtr->State == VAR_ADDED) {
VarNameSize = (UINTN) Variable.CurrPtr->NameSize;
if (VarNameSize <= *VariableNameSize) {
(*PeiServices)->CopyMem (VariableName, GET_VARIABLE_NAME_PTR (Variable.CurrPtr), VarNameSize);
(*PeiServices)->CopyMem (VendorGuid, &Variable.CurrPtr->VendorGuid, sizeof (EFI_GUID));
Status = EFI_SUCCESS;
} else {
Status = EFI_BUFFER_TOO_SMALL;
}
*VariableNameSize = VarNameSize;
return Status;
//
// Variable is found
//
} else {
Variable.CurrPtr = GetNextVariablePtr (Variable.CurrPtr);
}
} else {
break;
}
}
return EFI_NOT_FOUND;
}
|