remove the duplicate guid.

[mirror_edk2.git] / IntelFrameworkModulePkg / Universal / VariablePei / Variable.c

/*++\r
\r
Copyright (c) 2006 - 2007 Intel Corporation. <BR>\r
All rights reserved. This program and the accompanying materials\r
are licensed and made available under the terms and conditions of the BSD License\r
which accompanies this distribution.  The full text of the license may be found at\r
http://opensource.org/licenses/bsd-license.php\r
\r
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
Module Name:\r
\r
  Variable.c\r
\r
Abstract:\r
\r
  Framework PEIM to provide the Variable functionality\r
\r
--*/\r
\r
\r
#include "Variable.h"\r
\r
//\r
// Module globals\r
//\r
static EFI_PEI_READ_ONLY_VARIABLE_PPI mVariablePpi = {\r
  PeiGetVariable,\r
  PeiGetNextVariableName\r
};\r
\r
static EFI_PEI_READ_ONLY_VARIABLE2_PPI mVariable2Ppi = {\r
  PeiGetVariable2,\r
  PeiGetNextVariableName2\r
};\r
\r
static EFI_PEI_PPI_DESCRIPTOR     mPpiListVariable[] = {\r
  {\r
    (EFI_PEI_PPI_DESCRIPTOR_PPI),\r
    &gEfiPeiReadOnlyVariable2PpiGuid,\r
    &mVariable2Ppi\r
  },\r
  {\r
    (EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),\r
    &gEfiPeiReadOnlyVariablePpiGuid,\r
    &mVariablePpi\r
  }\r
};\r
\r
EFI_GUID mEfiVariableIndexTableGuid = EFI_VARIABLE_INDEX_TABLE_GUID;\r
\r
EFI_STATUS\r
EFIAPI\r
PeimInitializeVariableServices (\r
  IN EFI_FFS_FILE_HEADER       *FfsHeader,\r
  IN EFI_PEI_SERVICES          **PeiServices\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  Provide the functionality of the variable services.\r
\r
Arguments:\r
\r
  FfsHeadher  - The FFS file header\r
  PeiServices - General purpose services available to every PEIM.\r
\r
Returns:\r
\r
  Status -  EFI_SUCCESS if the interface could be successfully\r
            installed\r
\r
--*/\r
{\r
  //\r
  // Publish the variable capability to other modules\r
  //\r
  return (**PeiServices).InstallPpi ((CONST EFI_PEI_SERVICES **) PeiServices, &mPpiListVariable[0]);\r
\r
}\r
\r
VARIABLE_HEADER *\r
GetStartPointer (\r
  IN VARIABLE_STORE_HEADER       *VarStoreHeader\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  This code gets the pointer to the first variable memory pointer byte\r
\r
Arguments:\r
\r
  VarStoreHeader        Pointer to the Variable Store Header.\r
\r
Returns:\r
\r
  VARIABLE_HEADER*      Pointer to last unavailable Variable Header\r
\r
--*/\r
{\r
  //\r
  // The end of variable store\r
  //\r
  return (VARIABLE_HEADER *) HEADER_ALIGN (VarStoreHeader + 1);\r
}\r
\r
VARIABLE_HEADER *\r
GetEndPointer (\r
  IN VARIABLE_STORE_HEADER       *VarStoreHeader\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  This code gets the pointer to the last variable memory pointer byte\r
\r
Arguments:\r
\r
  VarStoreHeader        Pointer to the Variable Store Header.\r
\r
Returns:\r
\r
  VARIABLE_HEADER*      Pointer to last unavailable Variable Header\r
\r
--*/\r
{\r
  //\r
  // The end of variable store\r
  //\r
  return (VARIABLE_HEADER *) HEADER_ALIGN ((UINTN) VarStoreHeader + VarStoreHeader->Size);\r
}\r
\r
STATIC\r
BOOLEAN\r
EFIAPI\r
IsValidVariableHeader (\r
  IN  VARIABLE_HEADER   *Variable\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  This code checks if variable header is valid or not.\r
\r
Arguments:\r
  Variable              Pointer to the Variable Header.\r
\r
Returns:\r
  TRUE            Variable header is valid.\r
  FALSE           Variable header is not valid.\r
\r
--*/\r
{\r
  if (Variable == NULL || Variable->StartId != VARIABLE_DATA ) {\r
    return FALSE;\r
  }\r
\r
  return TRUE;\r
}\r
\r
\r
UINTN\r
NameSizeOfVariable (\r
  IN  VARIABLE_HEADER   *Variable\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  This code gets the size of name of variable.\r
\r
Arguments:\r
\r
  Variable            Pointer to the Variable Header.\r
\r
Returns:\r
\r
  UINTN               Size of variable in bytes\r
\r
--*/\r
{\r
  if (Variable->State    == (UINT8) (-1) ||\r
      Variable->DataSize == (UINT32) -1 ||\r
      Variable->NameSize == (UINT32) -1 ||\r
      Variable->Attributes == (UINT32) -1) {\r
    return 0;\r
  }\r
  return (UINTN) Variable->NameSize;\r
}\r
\r
UINTN\r
DataSizeOfVariable (\r
  IN  VARIABLE_HEADER   *Variable\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  This code gets the size of name of variable.\r
\r
Arguments:\r
\r
  Variable            Pointer to the Variable Header.\r
\r
Returns:\r
\r
  UINTN               Size of variable in bytes\r
\r
--*/\r
{\r
  if (Variable->State    == (UINT8)  -1 ||\r
      Variable->DataSize == (UINT32) -1 ||\r
      Variable->NameSize == (UINT32) -1 ||\r
      Variable->Attributes == (UINT32) -1) {\r
    return 0;\r
  }\r
  return (UINTN) Variable->DataSize;\r
}\r
\r
CHAR16 *\r
GetVariableNamePtr (\r
  IN  VARIABLE_HEADER   *Variable\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  This code gets the pointer to the variable name.\r
\r
Arguments:\r
\r
  Variable            Pointer to the Variable Header.\r
\r
Returns:\r
\r
  CHAR16*              Pointer to Variable Name\r
\r
--*/\r
{\r
\r
  return (CHAR16 *) (Variable + 1);\r
}\r
\r
\r
UINT8 *\r
GetVariableDataPtr (\r
  IN  VARIABLE_HEADER   *Variable\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  This code gets the pointer to the variable data.\r
\r
Arguments:\r
\r
  Variable            Pointer to the Variable Header.\r
\r
Returns:\r
\r
  UINT8*              Pointer to Variable Data\r
\r
--*/\r
{\r
  UINTN Value;\r
  \r
  //\r
  // Be careful about pad size for alignment\r
  //\r
  Value =  (UINTN) GetVariableNamePtr (Variable);\r
  Value += NameSizeOfVariable (Variable);\r
  Value += GET_PAD_SIZE (NameSizeOfVariable (Variable));\r
\r
  return (UINT8 *) Value;\r
}\r
\r
VARIABLE_HEADER *\r
GetNextVariablePtr (\r
  IN  VARIABLE_HEADER   *Variable\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  This code gets the pointer to the next variable header.\r
\r
Arguments:\r
\r
  Variable              Pointer to the Variable Header.\r
\r
Returns:\r
\r
  VARIABLE_HEADER*      Pointer to next variable header.\r
\r
--*/\r
{\r
  UINTN Value;\r
\r
  if (!IsValidVariableHeader (Variable)) {\r
    return NULL;\r
  }\r
\r
  Value =  (UINTN) GetVariableDataPtr (Variable);\r
  Value += DataSizeOfVariable (Variable);\r
  Value += GET_PAD_SIZE (DataSizeOfVariable (Variable));\r
\r
  //\r
  // Be careful about pad size for alignment\r
  //\r
  return (VARIABLE_HEADER *) HEADER_ALIGN (Value);\r
}\r
\r
\r
STATIC\r
VARIABLE_STORE_STATUS\r
EFIAPI\r
GetVariableStoreStatus (\r
  IN VARIABLE_STORE_HEADER *VarStoreHeader\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  This code gets the pointer to the variable name.\r
\r
Arguments:\r
\r
  VarStoreHeader  Pointer to the Variable Store Header.\r
\r
Returns:\r
\r
  EfiRaw        Variable store is raw\r
  EfiValid      Variable store is valid\r
  EfiInvalid    Variable store is invalid\r
\r
--*/\r
{\r
  if (VarStoreHeader->Signature == VARIABLE_STORE_SIGNATURE &&\r
      VarStoreHeader->Format == VARIABLE_STORE_FORMATTED &&\r
      VarStoreHeader->State == VARIABLE_STORE_HEALTHY\r
      ) {\r
\r
    return EfiValid;\r
  }\r
\r
  if (VarStoreHeader->Signature == 0xffffffff &&\r
      VarStoreHeader->Size == 0xffffffff &&\r
      VarStoreHeader->Format == 0xff &&\r
      VarStoreHeader->State == 0xff\r
      ) {\r
\r
    return EfiRaw;\r
  } else {\r
    return EfiInvalid;\r
  }\r
}\r
\r
STATIC\r
EFI_STATUS\r
CompareWithValidVariable (\r
  IN  VARIABLE_HEADER               *Variable,\r
  IN  CONST CHAR16                  *VariableName,\r
  IN  CONST EFI_GUID                *VendorGuid,\r
  OUT VARIABLE_POINTER_TRACK        *PtrTrack\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  This function compares a variable with variable entries in database\r
\r
Arguments:\r
\r
  Variable       - Pointer to the variable in our database\r
  VariableName   - Name of the variable to compare to 'Variable'\r
  VendorGuid     - GUID of the variable to compare to 'Variable'\r
  PtrTrack       - Variable Track Pointer structure that contains\r
                   Variable Information.\r
\r
Returns:\r
\r
  EFI_SUCCESS    - Found match variable\r
  EFI_NOT_FOUND  - Variable not found\r
\r
--*/\r
{\r
  VOID  *Point;\r
\r
  if (VariableName[0] == 0) {\r
    PtrTrack->CurrPtr = Variable;\r
    return EFI_SUCCESS;\r
  } else {\r
    //\r
    // Don't use CompareGuid function here for performance reasons.\r
    // Instead we compare the GUID a UINT32 at a time and branch\r
    // on the first failed comparison.\r
    //\r
    if ((((INT32 *) VendorGuid)[0] == ((INT32 *) &Variable->VendorGuid)[0]) &&\r
        (((INT32 *) VendorGuid)[1] == ((INT32 *) &Variable->VendorGuid)[1]) &&\r
        (((INT32 *) VendorGuid)[2] == ((INT32 *) &Variable->VendorGuid)[2]) &&\r
        (((INT32 *) VendorGuid)[3] == ((INT32 *) &Variable->VendorGuid)[3])\r
        ) {\r
      ASSERT (NameSizeOfVariable (Variable) != 0);\r
      Point = (VOID *) GetVariableNamePtr (Variable);\r
      if (!CompareMem (VariableName, Point, NameSizeOfVariable (Variable))) {\r
        PtrTrack->CurrPtr = Variable;\r
        return EFI_SUCCESS;\r
      }\r
    }\r
  }\r
\r
  return EFI_NOT_FOUND;\r
}\r
\r
STATIC\r
EFI_STATUS\r
EFIAPI\r
FindVariable (\r
  IN EFI_PEI_SERVICES         **PeiServices,\r
  IN CONST  CHAR16            *VariableName,\r
  IN CONST  EFI_GUID          *VendorGuid,\r
  OUT VARIABLE_POINTER_TRACK  *PtrTrack\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  This code finds variable in storage blocks (Non-Volatile)\r
\r
Arguments:\r
\r
  PeiServices    - General purpose services available to every PEIM.\r
  VariableName   - Name of the variable to be found\r
  VendorGuid     - Vendor GUID to be found.\r
  PtrTrack       - Variable Track Pointer structure that contains\r
                   Variable Information.\r
\r
Returns:\r
\r
  EFI_SUCCESS      - Variable found successfully\r
  EFI_NOT_FOUND    - Variable not found\r
  EFI_INVALID_PARAMETER  - Invalid variable name\r
\r
--*/\r
{\r
  EFI_HOB_GUID_TYPE       *GuidHob;\r
  VARIABLE_STORE_HEADER   *VariableStoreHeader;\r
  VARIABLE_HEADER         *Variable;\r
  VARIABLE_HEADER         *MaxIndex;\r
  VARIABLE_INDEX_TABLE    *IndexTable;\r
  UINT32                  Count;\r
  UINT8                   *VariableBase;\r
\r
  if (VariableName != 0 && VendorGuid == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
  //\r
  // No Variable Address equals zero, so 0 as initial value is safe.\r
  //\r
  MaxIndex = 0;\r
\r
  GuidHob = GetFirstGuidHob (&mEfiVariableIndexTableGuid);\r
  if (GuidHob == NULL) {\r
    IndexTable = BuildGuidHob (&mEfiVariableIndexTableGuid, sizeof (VARIABLE_INDEX_TABLE));\r
    IndexTable->Length      = 0;\r
    IndexTable->StartPtr    = NULL;\r
    IndexTable->EndPtr      = NULL;\r
    IndexTable->GoneThrough = 0;\r
  } else {\r
    IndexTable = GET_GUID_HOB_DATA (GuidHob);\r
    for (Count = 0; Count < IndexTable->Length; Count++)\r
    {\r
      MaxIndex = GetVariableByIndex (IndexTable, Count);\r
\r
      if (CompareWithValidVariable (MaxIndex, VariableName, VendorGuid, PtrTrack) == EFI_SUCCESS) {\r
        PtrTrack->StartPtr  = IndexTable->StartPtr;\r
        PtrTrack->EndPtr    = IndexTable->EndPtr;\r
\r
        return EFI_SUCCESS;\r
      }\r
    }\r
\r
    if (IndexTable->GoneThrough) {\r
      return EFI_NOT_FOUND;\r
    }\r
  }\r
  //\r
  // If not found in HOB, then let's start from the MaxIndex we've found.\r
  //\r
  if (MaxIndex != NULL) {\r
    Variable = GetNextVariablePtr (MaxIndex);\r
  } else {\r
    if (IndexTable->StartPtr || IndexTable->EndPtr) {\r
      Variable = IndexTable->StartPtr;\r
    } else {\r
      VariableBase = (UINT8 *) (UINTN) PcdGet32 (PcdFlashNvStorageVariableBase);\r
      VariableStoreHeader = (VARIABLE_STORE_HEADER *) (VariableBase + \\r
                            ((EFI_FIRMWARE_VOLUME_HEADER *) (VariableBase)) -> HeaderLength);\r
\r
      if (GetVariableStoreStatus (VariableStoreHeader) != EfiValid) {\r
        return EFI_UNSUPPORTED;\r
      }\r
\r
      if (~VariableStoreHeader->Size == 0) {\r
        return EFI_NOT_FOUND;\r
      }\r
      //\r
      // Find the variable by walk through non-volatile variable store\r
      //\r
      IndexTable->StartPtr  = GetStartPointer (VariableStoreHeader);\r
      IndexTable->EndPtr    = GetEndPointer (VariableStoreHeader);\r
\r
      //\r
      // Start Pointers for the variable.\r
      // Actual Data Pointer where data can be written.\r
      //\r
      Variable = IndexTable->StartPtr;\r
    }\r
  }\r
  //\r
  // Find the variable by walk through non-volatile variable store\r
  //\r
  PtrTrack->StartPtr  = IndexTable->StartPtr;\r
  PtrTrack->EndPtr    = IndexTable->EndPtr;\r
\r
  while (IsValidVariableHeader (Variable) && (Variable <= IndexTable->EndPtr)) {\r
    if (Variable->State == VAR_ADDED) {\r
      //\r
      // Record Variable in VariableIndex HOB\r
      //\r
      if (IndexTable->Length < VARIABLE_INDEX_TABLE_VOLUME)\r
      {\r
        VariableIndexTableUpdate (IndexTable, Variable);\r
      }\r
\r
      if (CompareWithValidVariable (Variable, VariableName, VendorGuid, PtrTrack) == EFI_SUCCESS) {\r
        return EFI_SUCCESS;\r
      }\r
    }\r
\r
    Variable = GetNextVariablePtr (Variable);\r
  }\r
  //\r
  // If gone through the VariableStore, that means we never find in Firmware any more.\r
  //\r
  if (IndexTable->Length < VARIABLE_INDEX_TABLE_VOLUME) {\r
    IndexTable->GoneThrough = 1;\r
  }\r
\r
  PtrTrack->CurrPtr = NULL;\r
\r
  return EFI_NOT_FOUND;\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
PeiGetVariable (\r
  IN EFI_PEI_SERVICES             **PeiServices,\r
  IN CHAR16                       *VariableName,\r
  IN EFI_GUID                     * VendorGuid,\r
  OUT UINT32                             *Attributes OPTIONAL,\r
  IN OUT UINTN                           *DataSize,\r
  OUT VOID                               *Data\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  Provide the read variable functionality of the variable services.\r
\r
Arguments:\r
\r
  PeiServices - General purpose services available to every PEIM.\r
\r
  VariableName     - The variable name\r
\r
  VendorGuid       - The vendor's GUID\r
\r
  Attributes       - Pointer to the attribute\r
\r
  DataSize         - Size of data\r
\r
  Data             - Pointer to data\r
\r
Returns:\r
\r
  EFI_SUCCESS           - The interface could be successfully installed\r
\r
  EFI_NOT_FOUND         - The variable could not be discovered\r
\r
  EFI_BUFFER_TOO_SMALL  - The caller buffer is not large enough\r
\r
--*/\r
{\r
  VARIABLE_POINTER_TRACK  Variable;\r
  UINTN                   VarDataSize;\r
  EFI_STATUS              Status;\r
\r
  if (VariableName == NULL || VendorGuid == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
  //\r
  // Find existing variable\r
  //\r
  Status = FindVariable (PeiServices, VariableName, VendorGuid, &Variable);\r
\r
  if (Variable.CurrPtr == NULL || Status != EFI_SUCCESS) {\r
    return Status;\r
  }\r
  //\r
  // Get data size\r
  //\r
  VarDataSize = DataSizeOfVariable (Variable.CurrPtr);\r
  if (*DataSize >= VarDataSize) {\r
    (*PeiServices)->CopyMem (Data, GetVariableDataPtr (Variable.CurrPtr), VarDataSize);\r
\r
    if (Attributes != NULL) {\r
      *Attributes = Variable.CurrPtr->Attributes;\r
    }\r
\r
    *DataSize = VarDataSize;\r
    return EFI_SUCCESS;\r
  } else {\r
    *DataSize = VarDataSize;\r
    return EFI_BUFFER_TOO_SMALL;\r
  }\r
}\r
\r
\r
EFI_STATUS\r
EFIAPI\r
PeiGetVariable2 (\r
  IN CONST  EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,\r
  IN CONST  CHAR16                          *VariableName,\r
  IN CONST  EFI_GUID                        *VariableGuid,\r
  OUT       UINT32                          *Attributes,\r
  IN OUT    UINTN                           *DataSize,\r
  OUT       VOID                            *Data\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  Provide the read variable functionality of the variable services.\r
\r
Arguments:\r
\r
  PeiServices - General purpose services available to every PEIM.\r
\r
  VariableName     - The variable name\r
\r
  VendorGuid       - The vendor's GUID\r
\r
  Attributes       - Pointer to the attribute\r
\r
  DataSize         - Size of data\r
\r
  Data             - Pointer to data\r
\r
Returns:\r
\r
  EFI_SUCCESS           - The interface could be successfully installed\r
\r
  EFI_NOT_FOUND         - The variable could not be discovered\r
\r
  EFI_BUFFER_TOO_SMALL  - The caller buffer is not large enough\r
\r
--*/\r
{\r
  return PeiGetVariable (\r
           GetPeiServicesTablePointer (),\r
           (CHAR16*)VariableName,\r
           (EFI_GUID*)VariableGuid,\r
           Attributes,\r
           DataSize,\r
           Data\r
           );\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
PeiGetNextVariableName (\r
  IN EFI_PEI_SERVICES             **PeiServices,\r
  IN OUT UINTN                    *VariableNameSize,\r
  IN OUT CHAR16                   *VariableName,\r
  IN OUT EFI_GUID                 *VendorGuid\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  Provide the get next variable functionality of the variable services.\r
\r
Arguments:\r
\r
  PeiServices        - General purpose services available to every PEIM.\r
  VariabvleNameSize  - The variable name's size.\r
  VariableName       - A pointer to the variable's name.\r
  VendorGuid         - A pointer to the EFI_GUID structure.\r
\r
  VariableNameSize - Size of the variable name\r
\r
  VariableName     - The variable name\r
\r
  VendorGuid       - The vendor's GUID\r
\r
Returns:\r
\r
  EFI_SUCCESS - The interface could be successfully installed\r
\r
  EFI_NOT_FOUND - The variable could not be discovered\r
\r
--*/\r
{\r
  VARIABLE_POINTER_TRACK  Variable;\r
  UINTN                   VarNameSize;\r
  EFI_STATUS              Status;\r
\r
  if (VariableName == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Status = FindVariable (PeiServices, VariableName, VendorGuid, &Variable);\r
\r
  if (Variable.CurrPtr == NULL || Status != EFI_SUCCESS) {\r
    return Status;\r
  }\r
\r
  if (VariableName[0] != 0) {\r
    //\r
    // If variable name is not NULL, get next variable\r
    //\r
    Variable.CurrPtr = GetNextVariablePtr (Variable.CurrPtr);\r
  }\r
\r
  while (!(Variable.CurrPtr >= Variable.EndPtr || Variable.CurrPtr == NULL)) {\r
    if (IsValidVariableHeader (Variable.CurrPtr)) {\r
      if (Variable.CurrPtr->State == VAR_ADDED) {\r
        ASSERT (NameSizeOfVariable (Variable.CurrPtr) != 0);\r
\r
        VarNameSize = (UINTN) NameSizeOfVariable (Variable.CurrPtr);\r
        if (VarNameSize <= *VariableNameSize) {\r
          (*PeiServices)->CopyMem (VariableName, GetVariableNamePtr (Variable.CurrPtr), VarNameSize);\r
\r
          (*PeiServices)->CopyMem (VendorGuid, &Variable.CurrPtr->VendorGuid, sizeof (EFI_GUID));\r
\r
          Status = EFI_SUCCESS;\r
        } else {\r
          Status = EFI_BUFFER_TOO_SMALL;\r
        }\r
\r
        *VariableNameSize = VarNameSize;\r
        return Status;\r
        //\r
        // Variable is found\r
        //\r
      } else {\r
        Variable.CurrPtr = GetNextVariablePtr (Variable.CurrPtr);\r
      }\r
    } else {\r
      break;\r
    }\r
  }\r
\r
  return EFI_NOT_FOUND;\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
PeiGetNextVariableName2 (\r
  IN CONST  EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,\r
  IN OUT UINTN                              *VariableNameSize,\r
  IN OUT CHAR16                             *VariableName,\r
  IN OUT EFI_GUID                           *VariableGuid\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  Provide the get next variable functionality of the variable services.\r
\r
Arguments:\r
\r
  PeiServices        - General purpose services available to every PEIM.\r
  VariabvleNameSize  - The variable name's size.\r
  VariableName       - A pointer to the variable's name.\r
  VariableGuid       - A pointer to the EFI_GUID structure.\r
\r
  VariableNameSize - Size of the variable name\r
\r
  VariableName     - The variable name\r
\r
  VendorGuid       - The vendor's GUID\r
\r
Returns:\r
\r
  EFI_SUCCESS - The interface could be successfully installed\r
\r
  EFI_NOT_FOUND - The variable could not be discovered\r
\r
--*/\r
{\r
  return PeiGetNextVariableName (\r
           GetPeiServicesTablePointer (),\r
           VariableNameSize,\r
           VariableName,\r
           VariableGuid\r
           );\r
}\r