text: /** @file
    PCD DXE driver manage all PCD entry initialized in PEI phase and DXE phase, and
    produce the implementation of native PCD protocol and EFI_PCD_PROTOCOL defined in
    PI 1.4a Vol3.
  
  Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
  SPDX-License-Identifier: BSD-2-Clause-Patent
  
  **/
  
  #include "Service.h"
  
  ///
  /// PCD database lock.
  ///
  EFI_LOCK mPcdDatabaseLock = EFI_INITIALIZE_LOCK_VARIABLE(TPL_NOTIFY);
  
  ///
  /// PCD_PROTOCOL the EDKII native implementation which support dynamic
  /// type and dynamicEx type PCDs.
  ///
  PCD_PROTOCOL mPcdInstance = {
    DxePcdSetSku,
  
    DxePcdGet8,
    DxePcdGet16,
    DxePcdGet32,
    DxePcdGet64,
    DxePcdGetPtr,
    DxePcdGetBool,
    DxePcdGetSize,
  
    DxePcdGet8Ex,
    DxePcdGet16Ex,
    DxePcdGet32Ex,
    DxePcdGet64Ex,
    DxePcdGetPtrEx,
    DxePcdGetBoolEx,
    DxePcdGetSizeEx,
  
    DxePcdSet8,
    DxePcdSet16,
    DxePcdSet32,
    DxePcdSet64,
    DxePcdSetPtr,
    DxePcdSetBool,
  
    DxePcdSet8Ex,
    DxePcdSet16Ex,
    DxePcdSet32Ex,
    DxePcdSet64Ex,
    DxePcdSetPtrEx,
    DxePcdSetBoolEx,
  
    DxeRegisterCallBackOnSet,
    DxeUnRegisterCallBackOnSet,
    DxePcdGetNextToken,
    DxePcdGetNextTokenSpace
  };
  
  ///
  /// EFI_PCD_PROTOCOL is defined in PI 1.2 Vol 3 which only support dynamicEx type
  /// PCD.
  ///
  EFI_PCD_PROTOCOL mEfiPcdInstance = {
    DxePcdSetSku,
    DxePcdGet8Ex,
    DxePcdGet16Ex,
    DxePcdGet32Ex,
    DxePcdGet64Ex,
    DxePcdGetPtrEx,
    DxePcdGetBoolEx,
    DxePcdGetSizeEx,
    DxePcdSet8Ex,
    DxePcdSet16Ex,
    DxePcdSet32Ex,
    DxePcdSet64Ex,
    DxePcdSetPtrEx,
    DxePcdSetBoolEx,
    (EFI_PCD_PROTOCOL_CALLBACK_ON_SET) DxeRegisterCallBackOnSet,
    (EFI_PCD_PROTOCOL_CANCEL_CALLBACK) DxeUnRegisterCallBackOnSet,
    DxePcdGetNextToken,
    DxePcdGetNextTokenSpace
  };
  
  ///
  /// Instance of GET_PCD_INFO_PROTOCOL protocol is EDKII native implementation.
  /// This protocol instance support dynamic and dynamicEx type PCDs.
  ///
  GET_PCD_INFO_PROTOCOL mGetPcdInfoInstance = {
    DxeGetPcdInfoGetInfo,
    DxeGetPcdInfoGetInfoEx,
    DxeGetPcdInfoGetSku
  };
  
  ///
  /// Instance of EFI_GET_PCD_INFO_PROTOCOL which is defined in PI 1.2.1 Vol 3.
  /// This PPI instance only support dyanmicEx type PCD.
  ///
  EFI_GET_PCD_INFO_PROTOCOL  mEfiGetPcdInfoInstance = {
    DxeGetPcdInfoGetInfoEx,
    DxeGetPcdInfoGetSku
  };
  
  EFI_HANDLE mPcdHandle = NULL;
  UINTN      mVpdBaseAddress = 0;
  
  /**
    Main entry for PCD DXE driver.
  
    This routine initialize the PCD database and install PCD_PROTOCOL.
  
    @param ImageHandle     Image handle for PCD DXE driver.
    @param SystemTable     Pointer to SystemTable.
  
    @return Status of gBS->InstallProtocolInterface()
  
  **/
  EFI_STATUS
  EFIAPI
  PcdDxeInit (
    IN EFI_HANDLE           ImageHandle,
    IN EFI_SYSTEM_TABLE     *SystemTable
    )
  {
    EFI_STATUS Status;
    VOID       *Registration;
  
    //
    // Make sure the Pcd Protocol is not already installed in the system
    //
  
    ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gPcdProtocolGuid);
  
    BuildPcdDxeDataBase ();
  
    //
    // Install PCD_PROTOCOL to handle dynamic type PCD
    // Install EFI_PCD_PROTOCOL to handle dynamicEx type PCD
    //
    Status = gBS->InstallMultipleProtocolInterfaces (
                    &mPcdHandle,
                    &gPcdProtocolGuid,     &mPcdInstance,
                    &gEfiPcdProtocolGuid,  &mEfiPcdInstance,
                    NULL
                    );
    ASSERT_EFI_ERROR (Status);
  
    //
    // Install GET_PCD_INFO_PROTOCOL to handle dynamic type PCD
    // Install EFI_GET_PCD_INFO_PROTOCOL to handle dynamicEx type PCD
    //
    Status = gBS->InstallMultipleProtocolInterfaces (
                    &mPcdHandle,
                    &gGetPcdInfoProtocolGuid,     &mGetPcdInfoInstance,
                    &gEfiGetPcdInfoProtocolGuid,  &mEfiGetPcdInfoInstance,
                    NULL
                    );
    ASSERT_EFI_ERROR (Status);
  
    //
    // Register callback function upon VariableLockProtocol
    // to lock the variables referenced by DynamicHii PCDs with RO property set in *.dsc.
    //
    EfiCreateProtocolNotifyEvent (
      &gEdkiiVariableLockProtocolGuid,
      TPL_CALLBACK,
      VariableLockCallBack,
      NULL,
      &Registration
      );
  
    //
    // Cache VpdBaseAddress in entry point for the following usage.
    //
  
    //
    // PcdVpdBaseAddress64 is DynamicEx PCD only. So, DxePcdGet64Ex() is used to get its value.
    //
    mVpdBaseAddress = (UINTN) DxePcdGet64Ex (&gEfiMdeModulePkgTokenSpaceGuid, PcdToken (PcdVpdBaseAddress64));
    if (mVpdBaseAddress == 0) {
      //
      // PcdVpdBaseAddress64 is not set, get value from PcdVpdBaseAddress.
      //
      mVpdBaseAddress = (UINTN) PcdGet32 (PcdVpdBaseAddress);
    }
  
    return Status;
  }
  
  /**
    Retrieve additional information associated with a PCD token in the default token space.
  
    This includes information such as the type of value the TokenNumber is associated with as well as possible
    human readable name that is associated with the token.
  
    @param[in]    TokenNumber The PCD token number.
    @param[out]   PcdInfo     The returned information associated with the requested TokenNumber.
                              The caller is responsible for freeing the buffer that is allocated by callee for PcdInfo->PcdName.
  
    @retval  EFI_SUCCESS      The PCD information was returned successfully.
    @retval  EFI_NOT_FOUND    The PCD service could not find the requested token number.
  **/
  EFI_STATUS
  EFIAPI
  DxeGetPcdInfoGetInfo (
    IN        UINTN           TokenNumber,
    OUT       EFI_PCD_INFO    *PcdInfo
    )
  {
    return DxeGetPcdInfo (NULL, TokenNumber, PcdInfo);
  }
  
  /**
    Retrieve additional information associated with a PCD token.
  
    This includes information such as the type of value the TokenNumber is associated with as well as possible
    human readable name that is associated with the token.
  
    @param[in]    Guid        The 128-bit unique value that designates the namespace from which to extract the value.
    @param[in]    TokenNumber The PCD token number.
    @param[out]   PcdInfo     The returned information associated with the requested TokenNumber.
                              The caller is responsible for freeing the buffer that is allocated by callee for PcdInfo->PcdName.
  
    @retval  EFI_SUCCESS      The PCD information was returned successfully.
    @retval  EFI_NOT_FOUND    The PCD service could not find the requested token number.
  **/
  EFI_STATUS
  EFIAPI
  DxeGetPcdInfoGetInfoEx (
    IN CONST  EFI_GUID        *Guid,
    IN        UINTN           TokenNumber,
    OUT       EFI_PCD_INFO    *PcdInfo
    )
  {
    return DxeGetPcdInfo (Guid, TokenNumber, PcdInfo);
  }
  
  /**
    Retrieve the currently set SKU Id.
  
    @return   The currently set SKU Id. If the platform has not set at a SKU Id, then the
              default SKU Id value of 0 is returned. If the platform has set a SKU Id, then the currently set SKU
              Id is returned.
  **/
  UINTN
  EFIAPI
  DxeGetPcdInfoGetSku (
    VOID
    )
  {
    return (UINTN) mPcdDatabase.DxeDb->SystemSkuId;
  }
  
  /**
    Sets the SKU value for subsequent calls to set or get PCD token values.
  
    SetSku() sets the SKU Id to be used for subsequent calls to set or get PCD values.
    SetSku() is normally called only once by the system.
  
    For each item (token), the database can hold a single value that applies to all SKUs,
    or multiple values, where each value is associated with a specific SKU Id. Items with multiple,
    SKU-specific values are called SKU enabled.
  
    The SKU Id of zero is reserved as a default.
    For tokens that are not SKU enabled, the system ignores any set SKU Id and works with the
    single value for that token. For SKU-enabled tokens, the system will use the SKU Id set by the
    last call to SetSku(). If no SKU Id is set or the currently set SKU Id isn't valid for the specified token,
    the system uses the default SKU Id. If the system attempts to use the default SKU Id and no value has been
    set for that Id, the results are unpredictable.
  
    @param[in]  SkuId The SKU value that will be used when the PCD service will retrieve and
                set values associated with a PCD token.
  
  **/
  VOID
  EFIAPI
  DxePcdSetSku (
    IN  UINTN         SkuId
    )
  {
    SKU_ID     *SkuIdTable;
    UINTN      Index;
    EFI_STATUS Status;
  
    DEBUG ((DEBUG_INFO, "PcdDxe - SkuId 0x%lx is to be set.\n", (SKU_ID) SkuId));
  
    if (SkuId == mPcdDatabase.DxeDb->SystemSkuId) {
      //
      // The input SKU Id is equal to current SKU Id, return directly.
      //
      DEBUG ((DEBUG_INFO, "PcdDxe - SkuId is same to current system Sku.\n"));
      return;
    }
  
    if (mPcdDatabase.DxeDb->SystemSkuId != (SKU_ID) 0) {
      DEBUG ((DEBUG_ERROR, "PcdDxe - The SKU Id could be changed only once."));
      DEBUG ((
        DEBUG_ERROR,
        "PcdDxe - The SKU Id was set to 0x%lx already, it could not be set to 0x%lx any more.",
        mPcdDatabase.DxeDb->SystemSkuId,
        (SKU_ID) SkuId
        ));
      ASSERT (FALSE);
      return;
    }
  
    SkuIdTable = (SKU_ID *) ((UINT8 *) mPcdDatabase.DxeDb + mPcdDatabase.DxeDb->SkuIdTableOffset);
    for (Index = 0; Index < SkuIdTable[0]; Index++) {
      if (SkuId == SkuIdTable[Index + 1]) {
        DEBUG ((DEBUG_INFO, "PcdDxe - SkuId is found in SkuId table.\n"));
        Status = UpdatePcdDatabase (SkuId, TRUE);
        if (!EFI_ERROR (Status)) {
          mPcdDatabase.DxeDb->SystemSkuId = (SKU_ID) SkuId;
          DEBUG ((DEBUG_INFO, "PcdDxe - Set current SKU Id to 0x%lx.\n", (SKU_ID) SkuId));
          return;
        }
      }
    }
  
    //
    // Invalid input SkuId, the default SKU Id will be still used for the system.
    //
    DEBUG ((DEBUG_ERROR, "PcdDxe - Invalid input SkuId, the default SKU Id will be still used.\n"));
    return;
  }
  
  /**
    Retrieves an 8-bit value for a given PCD token.
  
    Retrieves the current byte-sized value for a PCD token number.
    If the TokenNumber is invalid, the results are unpredictable.
  
    @param[in]  TokenNumber The PCD token number.
  
    @return The UINT8 value.
  
  **/
  UINT8
  EFIAPI
  DxePcdGet8 (
    IN UINTN                    TokenNumber
    )
  {
    return *((UINT8 *) GetWorker (TokenNumber, sizeof (UINT8)));
  }
  
  /**
    Retrieves an 16-bit value for a given PCD token.
  
    Retrieves the current 16-bits value for a PCD token number.
    If the TokenNumber is invalid, the results are unpredictable.
  
    @param[in]  TokenNumber The PCD token number.
  
    @return The UINT16 value.
  
  **/
  UINT16
  EFIAPI
  DxePcdGet16 (
    IN UINTN                    TokenNumber
    )
  {
    return ReadUnaligned16 (GetWorker (TokenNumber, sizeof (UINT16)));
  }
  
  /**
    Retrieves an 32-bit value for a given PCD token.
  
    Retrieves the current 32-bits value for a PCD token number.
    If the TokenNumber is invalid, the results are unpredictable.
  
    @param[in]  TokenNumber The PCD token number.
  
    @return The UINT32 value.
  
  **/
  UINT32
  EFIAPI
  DxePcdGet32 (
    IN UINTN                    TokenNumber
    )
  {
    return ReadUnaligned32 (GetWorker (TokenNumber, sizeof (UINT32)));
  }
  
  /**
    Retrieves an 64-bit value for a given PCD token.
  
    Retrieves the current 64-bits value for a PCD token number.
    If the TokenNumber is invalid, the results are unpredictable.
  
    @param[in]  TokenNumber The PCD token number.
  
    @return The UINT64 value.
  
  **/
  UINT64
  EFIAPI
  DxePcdGet64 (
    IN UINTN                     TokenNumber
    )
  {
    return ReadUnaligned64(GetWorker (TokenNumber, sizeof (UINT64)));
  }
  
  /**
    Retrieves a pointer to a value for a given PCD token.
  
    Retrieves the current pointer to the buffer for a PCD token number.
    Do not make any assumptions about the alignment of the pointer that
    is returned by this function call.  If the TokenNumber is invalid,
    the results are unpredictable.
  
    @param[in]  TokenNumber The PCD token number.
  
    @return The pointer to the buffer to be retrived.
  
  **/
  VOID *
  EFIAPI
  DxePcdGetPtr (
    IN UINTN                     TokenNumber
    )
  {
    return GetWorker (TokenNumber, 0);
  }
  
  /**
    Retrieves a Boolean value for a given PCD token.
  
    Retrieves the current boolean value for a PCD token number.
    Do not make any assumptions about the alignment of the pointer that
    is returned by this function call.  If the TokenNumber is invalid,
    the results are unpredictable.
  
    @param[in]  TokenNumber The PCD token number.
  
    @return The Boolean value.
  
  **/
  BOOLEAN
  EFIAPI
  DxePcdGetBool (
    IN UINTN                     TokenNumber
    )
  {
    return *((BOOLEAN *) GetWorker (TokenNumber, sizeof (BOOLEAN)));
  }
  
  /**
    Retrieves the size of the value for a given PCD token.
  
    Retrieves the current size of a particular PCD token.
    If the TokenNumber is invalid, the results are unpredictable.
  
    @param[in]  TokenNumber The PCD token number.
  
    @return The size of the value for the PCD token.
  
  **/
  UINTN
  EFIAPI
  DxePcdGetSize (
    IN UINTN                     TokenNumber
    )
  {
    UINTN   Size;
    UINT32  *LocalTokenNumberTable;
    BOOLEAN IsPeiDb;
    UINTN   MaxSize;
    UINTN   TmpTokenNumber;
    //
    // TokenNumber Zero is reserved as PCD_INVALID_TOKEN_NUMBER.
    // We have to decrement TokenNumber by 1 to make it usable
    // as the array index.
    //
    TokenNumber--;
  
    //
    // Backup the TokenNumber passed in as GetPtrTypeSize need the original TokenNumber
    //
    TmpTokenNumber = TokenNumber;
  
    // EBC compiler is very choosy. It may report warning about comparison
    // between UINTN and 0 . So we add 1 in each size of the
    // comparison.
    ASSERT (TokenNumber + 1 < mPcdTotalTokenCount + 1);
  
    // EBC compiler is very choosy. It may report warning about comparison
    // between UINTN and 0 . So we add 1 in each size of the
    // comparison.
    IsPeiDb = (BOOLEAN) (TokenNumber + 1 < mPeiLocalTokenCount + 1);
  
    TokenNumber = IsPeiDb ? TokenNumber :
                            (TokenNumber - mPeiLocalTokenCount);
  
    LocalTokenNumberTable = IsPeiDb ? (UINT32 *)((UINT8 *)mPcdDatabase.PeiDb + mPcdDatabase.PeiDb->LocalTokenNumberTableOffset)
                                    : (UINT32 *)((UINT8 *)mPcdDatabase.DxeDb + mPcdDatabase.DxeDb->LocalTokenNumberTableOffset);
  
    Size = (LocalTokenNumberTable[TokenNumber] & PCD_DATUM_TYPE_ALL_SET) >> PCD_DATUM_TYPE_SHIFT;
  
    if (Size == 0) {
      //
      // For pointer type, we need to scan the SIZE_TABLE to get the current size.
      //
      return GetPtrTypeSize (TmpTokenNumber, &MaxSize);
    } else {
      return Size;
    }
  
  }
  
  /**
    Retrieves an 8-bit value for a given PCD token.
  
    Retrieves the 8-bit value of a particular PCD token.
    If the TokenNumber is invalid or the token space
    specified by Guid does not exist, the results are
    unpredictable.
  
    @param[in]  Guid          The token space for the token number.
    @param[in]  ExTokenNumber The PCD token number.
  
    @return The size 8-bit value for the PCD token.
  
  **/
  UINT8
  EFIAPI
  DxePcdGet8Ex (
    IN CONST EFI_GUID         *Guid,
    IN UINTN                  ExTokenNumber
    )
  {
    return *((UINT8 *) ExGetWorker (Guid, ExTokenNumber, sizeof(UINT8)));
  }
  
  /**
    Retrieves an 16-bit value for a given PCD token.
  
    Retrieves the 16-bit value of a particular PCD token.
    If the TokenNumber is invalid or the token space
    specified by Guid does not exist, the results are
    unpredictable.
  
    @param[in]  Guid The token space for the token number.
    @param[in]  ExTokenNumber The PCD token number.
  
    @return The size 16-bit value for the PCD token.
  
  **/
  UINT16
  EFIAPI
  DxePcdGet16Ex (
    IN CONST EFI_GUID        *Guid,
    IN UINTN                ExTokenNumber
    )
  {
    return ReadUnaligned16 (ExGetWorker (Guid, ExTokenNumber, sizeof(UINT16)));
  }
  
  /**
    Retrieves an 32-bit value for a given PCD token.
  
    Retrieves the 32-bit value of a particular PCD token.
    If the TokenNumber is invalid or the token space
    specified by Guid does not exist, the results are
    unpredictable.
  
    @param[in]  Guid The token space for the token number.
    @param[in]  ExTokenNumber The PCD token number.
  
    @return The size 32-bit value for the PCD token.
  
  **/
  UINT32
  EFIAPI
  DxePcdGet32Ex (
    IN CONST EFI_GUID        *Guid,
    IN UINTN                 ExTokenNumber
    )
  {
    return ReadUnaligned32 (ExGetWorker (Guid, ExTokenNumber, sizeof(UINT32)));
  }
  
  /**
    Retrieves an 64-bit value for a given PCD token.
  
    Retrieves the 64-bit value of a particular PCD token.
    If the TokenNumber is invalid or the token space
    specified by Guid does not exist, the results are
    unpredictable.
  
    @param[in]  Guid The token space for the token number.
    @param[in]  ExTokenNumber The PCD token number.
  
    @return The size 64-bit value for the PCD token.
  
  **/
  UINT64
  EFIAPI
  DxePcdGet64Ex (
    IN CONST EFI_GUID        *Guid,
    IN UINTN                 ExTokenNumber
    )
  {
    return ReadUnaligned64 (ExGetWorker (Guid, ExTokenNumber, sizeof(UINT64)));
  }
  
  /**
    Retrieves a pointer to a value for a given PCD token.
  
    Retrieves the current pointer to the buffer for a PCD token number.
    Do not make any assumptions about the alignment of the pointer that
    is returned by this function call.  If the TokenNumber is invalid,
    the results are unpredictable.
  
    @param[in]  Guid The token space for the token number.
    @param[in]  ExTokenNumber The PCD token number.
  
    @return The pointer to the buffer to be retrived.
  
  **/
  VOID *
  EFIAPI
  DxePcdGetPtrEx (
    IN CONST EFI_GUID        *Guid,
    IN UINTN                 ExTokenNumber
    )
  {
    return  ExGetWorker (Guid, ExTokenNumber, 0);
  }
  
  /**
    Retrieves an Boolean value for a given PCD token.
  
    Retrieves the Boolean value of a particular PCD token.
    If the TokenNumber is invalid or the token space
    specified by Guid does not exist, the results are
    unpredictable.
  
    @param[in]  Guid The token space for the token number.
    @param[in]  ExTokenNumber The PCD token number.
  
    @return The size Boolean value for the PCD token.
  
  **/
  BOOLEAN
  EFIAPI
  DxePcdGetBoolEx (
    IN CONST EFI_GUID        *Guid,
    IN UINTN                 ExTokenNumber
    )
  {
    return *((BOOLEAN *) ExGetWorker (Guid, ExTokenNumber, sizeof(BOOLEAN)));
  }
  
  /**
    Retrieves the size of the value for a given PCD token.
  
    Retrieves the current size of a particular PCD token.
    If the TokenNumber is invalid, the results are unpredictable.
  
    @param[in]  Guid The token space for the token number.
    @param[in]  ExTokenNumber The PCD token number.
  
    @return The size of the value for the PCD token.
  
  **/
  UINTN
  EFIAPI
  DxePcdGetSizeEx (
    IN CONST EFI_GUID        *Guid,
    IN UINTN                 ExTokenNumber
    )
  {
    return DxePcdGetSize(GetExPcdTokenNumber (Guid, (UINT32) ExTokenNumber));
  }
  
  /**
    Sets an 8-bit value for a given PCD token.
  
    When the PCD service sets a value, it will check to ensure that the
    size of the value being set is compatible with the Token's existing definition.
    If it is not, an error will be returned.
  
    @param[in]  TokenNumber The PCD token number.
    @param[in]  Value The value to set for the PCD token.
  
    @retval EFI_SUCCESS  Procedure returned successfully.
    @retval EFI_INVALID_PARAMETER The PCD service determined that the size of the data
                                    being set was incompatible with a call to this function.
                                    Use GetSize() to retrieve the size of the target data.
    @retval EFI_NOT_FOUND The PCD service could not find the requested token number.
  
  **/
  EFI_STATUS
  EFIAPI
  DxePcdSet8 (
    IN UINTN              TokenNumber,
    IN UINT8              Value
    )
  {
    return SetValueWorker (TokenNumber, &Value, sizeof (Value));
  }
  
  /**
    Sets an 16-bit value for a given PCD token.
  
    When the PCD service sets a value, it will check to ensure that the
    size of the value being set is compatible with the Token's existing definition.
    If it is not, an error will be returned.
  
    @param[in]  TokenNumber The PCD token number.
    @param[in]  Value The value to set for the PCD token.
  
    @retval EFI_SUCCESS  Procedure returned successfully.
    @retval EFI_INVALID_PARAMETER The PCD service determined that the size of the data
                                    being set was incompatible with a call to this function.
                                    Use GetSize() to retrieve the size of the target data.
    @retval EFI_NOT_FOUND The PCD service could not find the requested token number.
  
  **/
  EFI_STATUS
  EFIAPI
  DxePcdSet16 (
    IN UINTN              TokenNumber,
    IN UINT16             Value
    )
  {
    return SetValueWorker (TokenNumber, &Value, sizeof (Value));
  }
  
  /**
    Sets an 32-bit value for a given PCD token.
  
    When the PCD service sets a value, it will check to ensure that the
    size of the value being set is compatible with the Token's existing definition.
    If it is not, an error will be returned.
  
    @param[in]  TokenNumber The PCD token number.
    @param[in]  Value The value to set for the PCD token.
  
    @retval EFI_SUCCESS  Procedure returned successfully.
    @retval EFI_INVALID_PARAMETER The PCD service determined that the size of the data
                                    being set was incompatible with a call to this function.
                                    Use GetSize() to retrieve the size of the target data.
    @retval EFI_NOT_FOUND The PCD service could not find the requested token number.
  
  **/
  EFI_STATUS
  EFIAPI
  DxePcdSet32 (
    IN UINTN              TokenNumber,
    IN UINT32             Value
    )
  {
    return SetValueWorker (TokenNumber, &Value, sizeof (Value));
  }
  
  /**
    Sets an 64-bit value for a given PCD token.
  
    When the PCD service sets a value, it will check to ensure that the
    size of the value being set is compatible with the Token's existing definition.
    If it is not, an error will be returned.
  
    @param[in]  TokenNumber The PCD token number.
    @param[in]  Value The value to set for the PCD token.
  
    @retval EFI_SUCCESS  Procedure returned successfully.
    @retval EFI_INVALID_PARAMETER The PCD service determined that the size of the data
                                    being set was incompatible with a call to this function.
                                    Use GetSize() to retrieve the size of the target data.
    @retval EFI_NOT_FOUND The PCD service could not find the requested token number.
  
  **/
  EFI_STATUS
  EFIAPI
  DxePcdSet64 (
    IN UINTN              TokenNumber,
    IN UINT64             Value
    )
  {
    return SetValueWorker (TokenNumber, &Value, sizeof (Value));
  }
  
  /**
    Sets a value of a specified size for a given PCD token.
  
    When the PCD service sets a value, it will check to ensure that the
    size of the value being set is compatible with the Token's existing definition.
    If it is not, an error will be returned.
  
    @param[in]  TokenNumber The PCD token number.
    @param[in, out] SizeOfBuffer A pointer to the length of the value being set for the PCD token.
                                On input, if the SizeOfValue is greater than the maximum size supported
                                for this TokenNumber then the output value of SizeOfValue will reflect
                                the maximum size supported for this TokenNumber.
    @param[in]  Buffer The buffer to set for the PCD token.
  
    @retval EFI_SUCCESS  Procedure returned successfully.
    @retval EFI_INVALID_PARAMETER The PCD service determined that the size of the data
                                    being set was incompatible with a call to this function.
                                    Use GetSize() to retrieve the size of the target data.
    @retval EFI_NOT_FOUND The PCD service could not find the requested token number.
  
  **/
  EFI_STATUS
  EFIAPI
  DxePcdSetPtr (
    IN          UINTN              TokenNumber,
    IN OUT      UINTN              *SizeOfBuffer,
    IN          VOID               *Buffer
    )
  {
    return SetWorker (TokenNumber, Buffer, SizeOfBuffer, TRUE);
  }
  
  /**
    Sets an Boolean value for a given PCD token.
  
    When the PCD service sets a value, it will check to ensure that the
    size of the value being set is compatible with the Token's existing definition.
    If it is not, an error will be returned.
  
    @param[in]  TokenNumber The PCD token number.
    @param[in]  Value The value to set for the PCD token.
  
    @retval EFI_SUCCESS  Procedure returned successfully.
    @retval EFI_INVALID_PARAMETER The PCD service determined that the size of the data
                                    being set was incompatible with a call to this function.
                                    Use GetSize() to retrieve the size of the target data.
    @retval EFI_NOT_FOUND The PCD service could not find the requested token number.
  
  **/
  EFI_STATUS
  EFIAPI
  DxePcdSetBool (
    IN UINTN              TokenNumber,
    IN BOOLEAN            Value
    )
  {
    return SetValueWorker (TokenNumber, &Value, sizeof (Value));
  }
  
  /**
    Sets an 8-bit value for a given PCD token.
  
    When the PCD service sets a value, it will check to ensure that the
    size of the value being set is compatible with the Token's existing definition.
    If it is not, an error will be returned.
  
    @param[in]  Guid The 128-bit unique value that designates the namespace from which to extract the value.
    @param[in]  ExTokenNumber The PCD token number.
    @param[in]  Value The value to set for the PCD token.
  
    @retval EFI_SUCCESS  Procedure returned successfully.
    @retval EFI_INVALID_PARAMETER The PCD service determined that the size of the data
                                    being set was incompatible with a call to this function.
                                    Use GetSize() to retrieve the size of the target data.
    @retval EFI_NOT_FOUND The PCD service could not find the requested token number.
  
  **/
  EFI_STATUS
  EFIAPI
  DxePcdSet8Ex (
    IN CONST EFI_GUID         *Guid,
    IN UINTN                  ExTokenNumber,
    IN UINT8                  Value
    )
  {
    return  ExSetValueWorker (ExTokenNumber, Guid, &Value, sizeof (Value));
  }
  
  /**
    Sets an 16-bit value for a given PCD token.
  
    When the PCD service sets a value, it will check to ensure that the
    size of the value being set is compatible with the Token's existing definition.
    If it is not, an error will be returned.
  
    @param[in]  Guid The 128-bit unique value that designates the namespace from which to extract the value.
    @param[in]  ExTokenNumber The PCD token number.
    @param[in]  Value The value to set for the PCD token.
  
    @retval EFI_SUCCESS  Procedure returned successfully.
    @retval EFI_INVALID_PARAMETER The PCD service determined that the size of the data
                                    being set was incompatible with a call to this function.
                                    Use GetSize() to retrieve the size of the target data.
    @retval EFI_NOT_FOUND The PCD service could not find the requested token number.
  
  **/
  EFI_STATUS
  EFIAPI
  DxePcdSet16Ex (
    IN CONST EFI_GUID    *Guid,
    IN UINTN             ExTokenNumber,
    IN UINT16            Value
    )
  {
    //
    // PcdSetNvStoreDefaultId should be set in PEI phase to take effect.
    //
    ASSERT (!(CompareGuid (Guid, &gEfiMdeModulePkgTokenSpaceGuid) &&
              (ExTokenNumber == PcdToken(PcdSetNvStoreDefaultId))));
    return  ExSetValueWorker (ExTokenNumber, Guid, &Value, sizeof (Value));
  }
  
  /**
    Sets an 32-bit value for a given PCD token.
  
    When the PCD service sets a value, it will check to ensure that the
    size of the value being set is compatible with the Token's existing definition.
    If it is not, an error will be returned.
  
    @param[in]  Guid The 128-bit unique value that designates the namespace from which to extract the value.
    @param[in]  ExTokenNumber The PCD token number.
    @param[in]  Value The value to set for the PCD token.
  
    @retval EFI_SUCCESS  Procedure returned successfully.
    @retval EFI_INVALID_PARAMETER The PCD service determined that the size of the data
                                    being set was incompatible with a call to this function.
                                    Use GetSize() to retrieve the size of the target data.
    @retval EFI_NOT_FOUND The PCD service could not find the requested token number.
  
  **/
  EFI_STATUS
  EFIAPI
  DxePcdSet32Ex (
    IN CONST EFI_GUID     *Guid,
    IN UINTN              ExTokenNumber,
    IN UINT32             Value
    )
  {
    return  ExSetValueWorker (ExTokenNumber, Guid, &Value, sizeof (Value));
  }
  
  /**
    Sets an 64-bit value for a given PCD token.
  
    When the PCD service sets a value, it will check to ensure that the
    size of the value being set is compatible with the Token's existing definition.
    If it is not, an error will be returned.
  
    @param[in]  Guid The 128-bit unique value that designates the namespace from which to extract the value.
    @param[in]  ExTokenNumber The PCD token number.
    @param[in]  Value The value to set for the PCD token.
  
    @retval EFI_SUCCESS  Procedure returned successfully.
    @retval EFI_INVALID_PARAMETER The PCD service determined that the size of the data
                                    being set was incompatible with a call to this function.
                                    Use GetSize() to retrieve the size of the target data.
    @retval EFI_NOT_FOUND The PCD service could not find the requested token number.
  
  **/
  EFI_STATUS
  EFIAPI
  DxePcdSet64Ex (
    IN CONST EFI_GUID    *Guid,
    IN UINTN             ExTokenNumber,
    IN UINT64            Value
    )
  {
    return  ExSetValueWorker (ExTokenNumber, Guid, &Value, sizeof (Value));
  }
  
  /**
    Sets a value of a specified size for a given PCD token.
  
    When the PCD service sets a value, it will check to ensure that the
    size of the value being set is compatible with the Token's existing definition.
    If it is not, an error will be returned.
  
    @param[in]  Guid The 128-bit unique value that designates the namespace from which to extract the value.
    @param[in]  ExTokenNumber The PCD token number.
    @param[in, out] SizeOfBuffer A pointer to the length of the value being set for the PCD token.
                                On input, if the SizeOfValue is greater than the maximum size supported
                                for this TokenNumber then the output value of SizeOfValue will reflect
                                the maximum size supported for this TokenNumber.
    @param[in]  Buffer The buffer to set for the PCD token.
  
    @retval EFI_SUCCESS  Procedure returned successfully.
    @retval EFI_INVALID_PARAMETER The PCD service determined that the size of the data
                                    being set was incompatible with a call to this function.
                                    Use GetSize() to retrieve the size of the target data.
    @retval EFI_NOT_FOUND The PCD service could not find the requested token number.
  
  **/
  EFI_STATUS
  EFIAPI
  DxePcdSetPtrEx (
    IN            CONST EFI_GUID         *Guid,
    IN            UINTN                  ExTokenNumber,
    IN OUT        UINTN                  *SizeOfBuffer,
    IN            VOID                   *Buffer
    )
  {
    return  ExSetWorker(ExTokenNumber, Guid, Buffer, SizeOfBuffer, TRUE);
  }
  
  /**
    Sets an Boolean value for a given PCD token.
  
    When the PCD service sets a value, it will check to ensure that the
    size of the value being set is compatible with the Token's existing definition.
    If it is not, an error will be returned.
  
    @param[in]  Guid The 128-bit unique value that designates the namespace from which to extract the value.
    @param[in]  ExTokenNumber The PCD token number.
    @param[in]  Value The value to set for the PCD token.
  
    @retval EFI_SUCCESS  Procedure returned successfully.
    @retval EFI_INVALID_PARAMETER The PCD service determined that the size of the data
                                    being set was incompatible with a call to this function.
                                    Use GetSize() to retrieve the size of the target data.
    @retval EFI_NOT_FOUND The PCD service could not find the requested token number.
  
  **/
  EFI_STATUS
  EFIAPI
  DxePcdSetBoolEx (
    IN CONST EFI_GUID    *Guid,
    IN UINTN             ExTokenNumber,
    IN BOOLEAN           Value
    )
  {
    return  ExSetValueWorker (ExTokenNumber, Guid, &Value, sizeof (Value));
  }
  
  /**
    Specifies a function to be called anytime the value of a designated token is changed.
  
    @param[in]  Guid The 128-bit unique value that designates the namespace from which to extract the value.
    @param[in]  TokenNumber The PCD token number.
    @param[in]  CallBackFunction The function prototype called when the value associated with the CallBackToken is set.
  
    @retval EFI_SUCCESS  The PCD service has successfully established a call event
                          for the CallBackToken requested.
    @retval EFI_NOT_FOUND The PCD service could not find the referenced token number.
  
  **/
  EFI_STATUS
  EFIAPI
  DxeRegisterCallBackOnSet (
    IN  CONST EFI_GUID          *Guid, OPTIONAL
    IN  UINTN                   TokenNumber,
    IN  PCD_PROTOCOL_CALLBACK   CallBackFunction
    )
  {
    EFI_STATUS Status;
  
    if (CallBackFunction == NULL) {
      return EFI_INVALID_PARAMETER;
    }
    //
    // Aquire lock to prevent reentrance from TPL_CALLBACK level
    //
    EfiAcquireLock (&mPcdDatabaseLock);
  
    Status = DxeRegisterCallBackWorker (TokenNumber, Guid, CallBackFunction);
  
    EfiReleaseLock (&mPcdDatabaseLock);
  
    return Status;
  }
  
  /**
    Cancels a previously set callback function for a particular PCD token number.
  
    @param[in]  Guid The 128-bit unique value that designates the namespace from which to extract the value.
    @param[in]  TokenNumber The PCD token number.
    @param[in]  CallBackFunction The function prototype called when the value associated with the CallBackToken is set.
  
    @retval EFI_SUCCESS  The PCD service has successfully established a call event
                          for the CallBackToken requested.
    @retval EFI_NOT_FOUND The PCD service could not find the referenced token number.
  
  **/
  EFI_STATUS
  EFIAPI
  DxeUnRegisterCallBackOnSet (
    IN  CONST EFI_GUID          *Guid, OPTIONAL
    IN  UINTN                   TokenNumber,
    IN  PCD_PROTOCOL_CALLBACK   CallBackFunction
    )
  {
    EFI_STATUS Status;
  
    if (CallBackFunction == NULL) {
      return EFI_INVALID_PARAMETER;
    }
  
    //
    // Aquire lock to prevent reentrance from TPL_CALLBACK level
    //
    EfiAcquireLock (&mPcdDatabaseLock);
  
    Status = DxeUnRegisterCallBackWorker (TokenNumber, Guid, CallBackFunction);
  
    EfiReleaseLock (&mPcdDatabaseLock);
  
    return Status;
  }
  
  /**
    Retrieves the next valid token number in a given namespace.
  
    This is useful since the PCD infrastructure contains a sparse list of token numbers,
    and one cannot a priori know what token numbers are valid in the database.
  
    If TokenNumber is 0 and Guid is not NULL, then the first token from the token space specified by Guid is returned.
    If TokenNumber is not 0 and Guid is not NULL, then the next token in the token space specified by Guid is returned.
    If TokenNumber is 0 and Guid is NULL, then the first token in the default token space is returned.
    If TokenNumber is not 0 and Guid is NULL, then the next token in the default token space is returned.
    The token numbers in the default token space may not be related to token numbers in token spaces that are named by Guid.
    If the next token number can be retrieved, then it is returned in TokenNumber, and EFI_SUCCESS is returned.
    If TokenNumber represents the last token number in the token space specified by Guid, then EFI_NOT_FOUND is returned.
    If TokenNumber is not present in the token space specified by Guid, then EFI_NOT_FOUND is returned.
  
  
    @param[in]      Guid    The 128-bit unique value that designates the namespace from which to retrieve the next token.
                            This is an optional parameter that may be NULL.  If this parameter is NULL, then a request is
                            being made to retrieve tokens from the default token space.
    @param[in, out] TokenNumber
                            A pointer to the PCD token number to use to find the subsequent token number.
  
    @retval EFI_SUCCESS   The PCD service has retrieved the next valid token number.
    @retval EFI_NOT_FOUND The PCD service could not find data from the requested token number.
  
  **/
  EFI_STATUS
  EFIAPI
  DxePcdGetNextToken (
    IN CONST EFI_GUID         *Guid, OPTIONAL
    IN OUT   UINTN            *TokenNumber
    )
  {
    EFI_STATUS          Status;
    BOOLEAN             PeiExMapTableEmpty;
    BOOLEAN             DxeExMapTableEmpty;
  
    Status = EFI_NOT_FOUND;
    PeiExMapTableEmpty = mPeiExMapTableEmpty;
    DxeExMapTableEmpty = mDxeExMapTableEmpty;
  
    //
    // Scan the local token space
    //
    if (Guid == NULL) {
      // EBC compiler is very choosy. It may report warning about comparison
      // between UINTN and 0 . So we add 1 in each size of the
      // comparison.
      if (((*TokenNumber + 1 > mPeiNexTokenCount + 1) && (*TokenNumber + 1 <= mPeiLocalTokenCount + 1)) ||
          ((*TokenNumber + 1 > (mPeiLocalTokenCount + mDxeNexTokenCount + 1)))) {
        return EFI_NOT_FOUND;
      }
  
      (*TokenNumber)++;
      if ((*TokenNumber + 1 > mPeiNexTokenCount + 1) &&
          (*TokenNumber + 1 <= mPeiLocalTokenCount + 1)) {
        //
        // The first Non-Ex type Token Number for DXE PCD
        // database is mPeiLocalTokenCount + 1
        //
        if (mDxeNexTokenCount > 0) {
          *TokenNumber = mPeiLocalTokenCount + 1;
        } else {
          *TokenNumber = PCD_INVALID_TOKEN_NUMBER;
          return EFI_NOT_FOUND;
        }
      } else if (*TokenNumber + 1 > mDxeNexTokenCount + mPeiLocalTokenCount + 1) {
        *TokenNumber = PCD_INVALID_TOKEN_NUMBER;
        return EFI_NOT_FOUND;
      }
      return EFI_SUCCESS;
    }
  
    if (PeiExMapTableEmpty && DxeExMapTableEmpty) {
      return EFI_NOT_FOUND;
    }
  
    if (!PeiExMapTableEmpty) {
      Status = ExGetNextTokeNumber (
                          Guid,
                          TokenNumber,
                          (EFI_GUID *)((UINT8 *)mPcdDatabase.PeiDb + mPcdDatabase.PeiDb->GuidTableOffset),
                          mPeiGuidTableSize,
                          (DYNAMICEX_MAPPING *)((UINT8 *) mPcdDatabase.PeiDb + mPcdDatabase.PeiDb->ExMapTableOffset),
                          mPeiExMapppingTableSize
                          );
    }
  
    if (Status == EFI_SUCCESS) {
      return Status;
    }
  
    if (!DxeExMapTableEmpty) {
      Status = ExGetNextTokeNumber (
                          Guid,
                          TokenNumber,
                          (EFI_GUID *)((UINT8 *)mPcdDatabase.DxeDb + mPcdDatabase.DxeDb->GuidTableOffset),
                          mDxeGuidTableSize,
                          (DYNAMICEX_MAPPING *)((UINT8 *) mPcdDatabase.DxeDb + mPcdDatabase.DxeDb->ExMapTableOffset),
                          mDxeExMapppingTableSize
                          );
    }
  
    return Status;
  }
  
  /**
    Get all token space guid table which is different with given token space guid.
  
    @param ExMapTableSize  The size of ExMapTable in item
    @param ExMapTable      Token space guid table that want to be scaned.
    @param GuidTable       Guid table
  
    @return all token space guid table which is different with given token space guid.
  
  **/
  EFI_GUID **
  GetDistinctTokenSpace (
    IN OUT    UINTN             *ExMapTableSize,
    IN        DYNAMICEX_MAPPING *ExMapTable,
    IN        EFI_GUID          *GuidTable
    )
  {
    EFI_GUID  **DistinctTokenSpace;
    UINTN     OldGuidIndex;
    UINTN     TsIdx;
    UINTN     TempTsIdx;
    UINTN     Idx;
    BOOLEAN   Match;
  
    DistinctTokenSpace = AllocateZeroPool (*ExMapTableSize * sizeof (EFI_GUID *));
    ASSERT (DistinctTokenSpace != NULL);
  
    TsIdx = 0;
    OldGuidIndex = ExMapTable[0].ExGuidIndex;
    DistinctTokenSpace[TsIdx] = &GuidTable[OldGuidIndex];
    for (Idx = 1; Idx < *ExMapTableSize; Idx++) {
      Match = FALSE;
      OldGuidIndex = ExMapTable[Idx].ExGuidIndex;
      for (TempTsIdx = 0; TempTsIdx <= TsIdx; TempTsIdx++) {
        if (&GuidTable[OldGuidIndex] == DistinctTokenSpace[TempTsIdx]) {
          //
          // Have recorded this GUID.
          //
          Match = TRUE;
          break;
        }
      }
      if (!Match) {
        DistinctTokenSpace[++TsIdx] = &GuidTable[OldGuidIndex];
      }
    }
  
    //
    // The total number of Distinct Token Space
    // is TsIdx + 1 because we use TsIdx as a index
    // to the DistinctTokenSpace[]
    //
    *ExMapTableSize = TsIdx + 1;
    return DistinctTokenSpace;
  
  }
  
  /**
    Retrieves the next valid PCD token namespace for a given namespace.
  
    Gets the next valid token namespace for a given namespace. This is useful to traverse the valid
    token namespaces on a platform.
  
    @param[in, out]   Guid    An indirect pointer to EFI_GUID. On input it designates a known token
                              namespace from which the search will start. On output, it designates the next valid
                              token namespace on the platform. If *Guid is NULL, then the GUID of the first token
                              space of the current platform is returned. If the search cannot locate the next valid
                              token namespace, an error is returned and the value of *Guid is undefined.
  
    @retval  EFI_SUCCESS      The PCD service retrieved the value requested.
    @retval  EFI_NOT_FOUND    The PCD service could not find the next valid token namespace.
  
  **/
  EFI_STATUS
  EFIAPI
  DxePcdGetNextTokenSpace (
    IN OUT CONST EFI_GUID               **Guid
    )
  {
    UINTN               Idx;
    UINTN               Idx2;
    UINTN               Idx3;
    UINTN               PeiTokenSpaceTableSize;
    UINTN               DxeTokenSpaceTableSize;
    EFI_GUID            **PeiTokenSpaceTable;
    EFI_GUID            **DxeTokenSpaceTable;
    BOOLEAN             Match;
    BOOLEAN             PeiExMapTableEmpty;
    BOOLEAN             DxeExMapTableEmpty;
  
    ASSERT (Guid != NULL);
  
    PeiExMapTableEmpty = mPeiExMapTableEmpty;
    DxeExMapTableEmpty = mDxeExMapTableEmpty;
  
    if (PeiExMapTableEmpty && DxeExMapTableEmpty) {
      return EFI_NOT_FOUND;
    }
  
    if (TmpTokenSpaceBuffer[0] == NULL) {
      PeiTokenSpaceTableSize = 0;
  
      if (!PeiExMapTableEmpty) {
        PeiTokenSpaceTableSize = mPeiExMapppingTableSize / sizeof(DYNAMICEX_MAPPING);
        PeiTokenSpaceTable = GetDistinctTokenSpace (&PeiTokenSpaceTableSize,
                              (DYNAMICEX_MAPPING *)((UINT8 *)mPcdDatabase.PeiDb + mPcdDatabase.PeiDb->ExMapTableOffset),
                              (EFI_GUID *)((UINT8 *)mPcdDatabase.PeiDb + mPcdDatabase.PeiDb->GuidTableOffset)
                              );
        CopyMem (TmpTokenSpaceBuffer, PeiTokenSpaceTable, sizeof (EFI_GUID*) * PeiTokenSpaceTableSize);
        TmpTokenSpaceBufferCount = PeiTokenSpaceTableSize;
        FreePool (PeiTokenSpaceTable);
      }
  
      if (!DxeExMapTableEmpty) {
        DxeTokenSpaceTableSize = mDxeExMapppingTableSize / sizeof(DYNAMICEX_MAPPING);
        DxeTokenSpaceTable = GetDistinctTokenSpace (&DxeTokenSpaceTableSize,
                              (DYNAMICEX_MAPPING *)((UINT8 *)mPcdDatabase.DxeDb + mPcdDatabase.DxeDb->ExMapTableOffset),
                              (EFI_GUID *)((UINT8 *)mPcdDatabase.DxeDb + mPcdDatabase.DxeDb->GuidTableOffset)
                              );
  
        //
        // Make sure EFI_GUID in DxeTokenSpaceTable does not exist in PeiTokenSpaceTable
        //
        for (Idx2 = 0, Idx3 = PeiTokenSpaceTableSize; Idx2 < DxeTokenSpaceTableSize; Idx2++) {
          Match = FALSE;
          for (Idx = 0; Idx < PeiTokenSpaceTableSize; Idx++) {
            if (CompareGuid (TmpTokenSpaceBuffer[Idx], DxeTokenSpaceTable[Idx2])) {
              Match = TRUE;
              break;
            }
          }
          if (!Match) {
            TmpTokenSpaceBuffer[Idx3++] = DxeTokenSpaceTable[Idx2];
          }
        }
  
        TmpTokenSpaceBufferCount = Idx3;
        FreePool (DxeTokenSpaceTable);
      }
    }
  
    if (*Guid == NULL) {
      *Guid = TmpTokenSpaceBuffer[0];
      return EFI_SUCCESS;
    }
  
    for (Idx = 0; Idx < TmpTokenSpaceBufferCount; Idx++) {
      if (CompareGuid (*Guid, TmpTokenSpaceBuffer[Idx])) {
        if (Idx == TmpTokenSpaceBufferCount - 1) {
          //
          // It has been the last token namespace.
          //
          *Guid = NULL;
          return EFI_NOT_FOUND;
        } else {
          Idx++;
          *Guid = TmpTokenSpaceBuffer[Idx];
          return EFI_SUCCESS;
        }
      }
    }
  
    return EFI_NOT_FOUND;
  }
  
  
  