audk/MdeModulePkg/Library/UefiHiiLib/HiiLib.c

/** @file
  HII Library implementation that uses DXE protocols and services.

  Copyright (c) 2006 - 2008, Intel Corporation<BR>
  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.

**/

#include "InternalHiiLib.h"

//
// <ConfigHdr> Template
//
GLOBAL_REMOVE_IF_UNREFERENCED CONST CHAR16 mConfigHdrTemplate[] = L"GUID=00000000000000000000000000000000&NAME=0000&PATH=00";

//
// Form Browser2 Protocol
//
EFI_FORM_BROWSER2_PROTOCOL  *mUefiFormBrowser2 = NULL;

/**
  This funciton build the package list based on the package number,
  the GUID of the package list and the list of pointer which point to
  package header that defined by UEFI VFR compiler and StringGather
  tool.

  #pragma pack (push, 1)
  typedef struct {
    UINT32                  BinaryLength;
    EFI_HII_PACKAGE_HEADER  PackageHeader;
  } EDKII_AUTOGEN_PACKAGES_HEADER;
  #pragma pack (pop)

  If there is not enough resource for the new package list,
  the function will ASSERT.

  @param NumberOfPackages The number of packages be 
  @param GuidId          The GUID for the package list to be generated.
  @param Marker          The variable argument list. Each entry represent a specific package header that is
                         generated by VFR compiler and StrGather tool. The first 4 bytes is a UINT32 value
                         that indicate the overall length of the package.

  @return The pointer to the package list header.

**/
EFI_HII_PACKAGE_LIST_HEADER *
InternalHiiLibPreparePackages (
  IN UINTN           NumberOfPackages,
  IN CONST EFI_GUID  *GuidId,
  IN VA_LIST         Marker
  )
{
  EFI_HII_PACKAGE_LIST_HEADER *PackageListHeader;
  UINT8                       *PackageListData;
  UINT32                      PackageListLength;
  UINT32                      PackageLength;
  EFI_HII_PACKAGE_HEADER      PackageHeader;
  UINT8                       *PackageArray;
  UINTN                       Index;
  VA_LIST                     MarkerBackup;

  PackageListLength = sizeof (EFI_HII_PACKAGE_LIST_HEADER);

  MarkerBackup = Marker;

  //
  // Count the length of the final package list.
  //
  for (Index = 0; Index < NumberOfPackages; Index++) {
    CopyMem (&PackageLength, VA_ARG (Marker, VOID *), sizeof (UINT32));
    //
    // Do not count the BinaryLength field.
    //
    PackageListLength += (PackageLength - sizeof (UINT32));
  }

  //
  // Include the length of EFI_HII_PACKAGE_END
  //
  PackageListLength += sizeof (EFI_HII_PACKAGE_HEADER);
  PackageListHeader = AllocateZeroPool (PackageListLength);
  ASSERT (PackageListHeader != NULL);
  
  CopyGuid (&PackageListHeader->PackageListGuid, GuidId);
  PackageListHeader->PackageLength = PackageListLength;

  PackageListData = ((UINT8 *) PackageListHeader) + sizeof (EFI_HII_PACKAGE_LIST_HEADER);

  Marker = MarkerBackup;
  //
  // Prepare the final package list.
  //
  for (Index = 0; Index < NumberOfPackages; Index++) {
    PackageArray = (UINT8 *) VA_ARG (Marker, VOID *);
    //
    // CopyMem is used for UINT32 to cover the unaligned address access.
    //
    CopyMem (&PackageLength, PackageArray, sizeof (UINT32));
    PackageLength  -= sizeof (UINT32);
    PackageArray += sizeof (UINT32);
    CopyMem (PackageListData, PackageArray, PackageLength);
    PackageListData += PackageLength;
  }

  //
  // Append EFI_HII_PACKAGE_END
  //
  PackageHeader.Type = EFI_HII_PACKAGE_END;
  PackageHeader.Length = sizeof (EFI_HII_PACKAGE_HEADER);
  CopyMem (PackageListData, &PackageHeader, PackageHeader.Length);

  return PackageListHeader;
}

/**
  Assemble EFI_HII_PACKAGE_LIST according to the passed in packages.

  If GuidId is NULL, then ASSERT.
  If not enough resource to complete the operation, then ASSERT.

  @param  NumberOfPackages       Number of packages.
  @param  GuidId                 Package GUID.
  @param  ...                    Variable argument list for packages to be assembled.

  @return Pointer of EFI_HII_PACKAGE_LIST_HEADER.

**/
EFI_HII_PACKAGE_LIST_HEADER *
EFIAPI
HiiLibPreparePackageList (
  IN UINTN                    NumberOfPackages,
  IN CONST EFI_GUID           *GuidId,
  ...
  )
{
  EFI_HII_PACKAGE_LIST_HEADER *PackageListHeader;
  VA_LIST                     Marker;

  ASSERT (GuidId != NULL);

  VA_START (Marker, GuidId);
  PackageListHeader = InternalHiiLibPreparePackages (NumberOfPackages, GuidId, Marker);
  VA_END (Marker);

  return PackageListHeader;
}


/**
  This function allocates pool for an EFI_HII_PACKAGE_LIST structure
  with additional space that is big enough to host all packages described by the variable 
  argument list of package pointers.  The allocated structure is initialized using NumberOfPackages, 
  GuidId,  and the variable length argument list of package pointers.

  Then, EFI_HII_PACKAGE_LIST will be register to the default System HII Database. The
  Handle to the newly registered Package List is returned through HiiHandle.

  If HiiHandle is NULL, then ASSERT.

  @param  NumberOfPackages    The number of HII packages to register.
  @param  GuidId              Package List GUID ID.
  @param  DriverHandle        Optional. If not NULL, the DriverHandle on which an instance of DEVICE_PATH_PROTOCOL is installed.
                              This DriverHandle uniquely defines the device that the added packages are associated with.
  @param  HiiHandle           On output, the HiiHandle is update with the handle which can be used to retrieve the Package 
                              List later. If the functions failed to add the package to the default HII database, this value will
                              be set to NULL.
  @param  ...                 The variable argument list describing all HII Package.

  @return  EFI_SUCCESS         If the packages are successfully added to the default HII database.
  @return  EFI_OUT_OF_RESOURCE Not enough resource to complete the operation.

**/
EFI_STATUS
EFIAPI
HiiLibAddPackages (
  IN       UINTN               NumberOfPackages,
  IN CONST EFI_GUID            *GuidId,
  IN       EFI_HANDLE          DriverHandle, OPTIONAL
  OUT      EFI_HII_HANDLE      *HiiHandle,
  ...
  )
{
  VA_LIST                   Args;
  EFI_HII_PACKAGE_LIST_HEADER *PackageListHeader;
  EFI_STATUS                Status;

  ASSERT (HiiHandle != NULL);

  VA_START (Args, HiiHandle);
  PackageListHeader = InternalHiiLibPreparePackages (NumberOfPackages, GuidId, Args);

  Status      = gHiiDatabase->NewPackageList (gHiiDatabase, PackageListHeader, DriverHandle, HiiHandle);
  if (HiiHandle != NULL) {
    if (EFI_ERROR (Status)) {
      *HiiHandle = NULL;
    }
  }

  FreePool (PackageListHeader);
  VA_END (Args);
  
  return Status;
}

/**
  Removes a package list from the default HII database.

  If HiiHandle is NULL, then ASSERT.
  If HiiHandle is not a valid EFI_HII_HANDLE in the default HII database, then ASSERT.

  @param  HiiHandle                The handle that was previously registered to the data base that is requested for removal.
                                             List later.

**/
VOID
EFIAPI
HiiLibRemovePackages (
  IN      EFI_HII_HANDLE      HiiHandle
  )
{
  EFI_STATUS Status;
  ASSERT (IsHiiHandleRegistered (HiiHandle));

  Status = gHiiDatabase->RemovePackageList (gHiiDatabase, HiiHandle);
  ASSERT_EFI_ERROR (Status);
}


/**
  Determines the handles that are currently active in the database.
  It's the caller's responsibility to free handle buffer.

  If HandleBufferLength is NULL, then ASSERT.
  If HiiHandleBuffer is NULL, then ASSERT.

  @param  HandleBufferLength     On input, a pointer to the length of the handle
                                 buffer. On output, the length of the handle buffer
                                 that is required for the handles found.
  @param  HiiHandleBuffer        Pointer to an array of Hii Handles returned.

  @retval EFI_SUCCESS            Get an array of Hii Handles successfully.

**/
EFI_STATUS
EFIAPI
HiiLibGetHiiHandles (
  IN OUT UINTN                     *HandleBufferLength,
  OUT    EFI_HII_HANDLE            **HiiHandleBuffer
  )
{
  EFI_STATUS  Status;

  ASSERT (HandleBufferLength != NULL);
  ASSERT (HiiHandleBuffer != NULL);

  *HandleBufferLength = 0;
  *HiiHandleBuffer = NULL;

  //
  // Try to find the actual buffer size for HiiHandle Buffer.
  //
  Status = gHiiDatabase->ListPackageLists (
                                 gHiiDatabase,
                                 EFI_HII_PACKAGE_TYPE_ALL,
                                 NULL,
                                 HandleBufferLength,
                                 *HiiHandleBuffer
                                 );
  
  if (Status == EFI_BUFFER_TOO_SMALL) {
      *HiiHandleBuffer = AllocateZeroPool (*HandleBufferLength);
      ASSERT (*HiiHandleBuffer != NULL);
      Status = gHiiDatabase->ListPackageLists (
                                     gHiiDatabase,
                                     EFI_HII_PACKAGE_TYPE_ALL,
                                     NULL,
                                     HandleBufferLength,
                                     *HiiHandleBuffer
                                     );

      if (EFI_ERROR (Status)) {
        FreePool (*HiiHandleBuffer);
        *HiiHandleBuffer = NULL;
      }
  }

  return Status;
}

/**
  Extract Hii package list GUID for given HII handle.

  If HiiHandle could not be found in the default HII database, then ASSERT.
  If Guid is NULL, then ASSERT.

  @param  Handle              Hii handle
  @param  Guid                Package list GUID

  @retval EFI_SUCCESS            Successfully extract GUID from Hii database.

**/
EFI_STATUS
EFIAPI
HiiLibExtractGuidFromHiiHandle (
  IN      EFI_HII_HANDLE      Handle,
  OUT     EFI_GUID            *Guid
  )
{
  EFI_STATUS                   Status;
  UINTN                        BufferSize;
  EFI_HII_PACKAGE_LIST_HEADER  *HiiPackageList;

  ASSERT (Guid != NULL);
  ASSERT (IsHiiHandleRegistered (Handle));

  //
  // Get HII PackageList
  //
  BufferSize = 0;
  HiiPackageList = NULL;

  Status = gHiiDatabase->ExportPackageLists (gHiiDatabase, Handle, &BufferSize, HiiPackageList);
  ASSERT (Status != EFI_NOT_FOUND);
  
  if (Status == EFI_BUFFER_TOO_SMALL) {
    HiiPackageList = AllocatePool (BufferSize);
    ASSERT (HiiPackageList != NULL);

    Status = gHiiDatabase->ExportPackageLists (gHiiDatabase, Handle, &BufferSize, HiiPackageList);
  }
  if (EFI_ERROR (Status)) {
    FreePool (HiiPackageList);
    return Status;
  }

  //
  // Extract GUID
  //
  CopyGuid (Guid, &HiiPackageList->PackageListGuid);

  FreePool (HiiPackageList);

  return EFI_SUCCESS;
}

/**
  Find HII Handle in the default HII database associated with given Device Path.

  If DevicePath is NULL, then ASSERT.

  @param  DevicePath             Device Path associated with the HII package list
                                 handle.

  @retval Handle                 HII package list Handle associated with the Device
                                        Path.
  @retval NULL                   Hii Package list handle is not found.

**/
EFI_HII_HANDLE
EFIAPI
HiiLibDevicePathToHiiHandle (
  IN EFI_DEVICE_PATH_PROTOCOL   *DevicePath
  )
{
  EFI_STATUS                  Status;
  EFI_DEVICE_PATH_PROTOCOL    *TmpDevicePath;
  UINTN                       BufferSize;
  UINTN                       HandleCount;
  UINTN                       Index;
  EFI_HANDLE                  *Handles;
  EFI_HANDLE                  Handle;
  UINTN                       Size;
  EFI_HANDLE                  DriverHandle;
  EFI_HII_HANDLE              *HiiHandles;
  EFI_HII_HANDLE              HiiHandle;

  ASSERT (DevicePath != NULL);

  //
  // Locate Device Path Protocol handle buffer
  //
  Status = gBS->LocateHandleBuffer (
                  ByProtocol,
                  &gEfiDevicePathProtocolGuid,
                  NULL,
                  &HandleCount,
                  &Handles
                  );
  if (EFI_ERROR (Status)) {
    return NULL;
  }

  //
  // Search Driver Handle by Device Path
  //
  DriverHandle = NULL;
  BufferSize = GetDevicePathSize (DevicePath);
  for(Index = 0; Index < HandleCount; Index++) {
    Handle = Handles[Index];
    gBS->HandleProtocol (Handle, &gEfiDevicePathProtocolGuid, (VOID **) &TmpDevicePath);

    //
    // Check whether DevicePath match
    //
    Size = GetDevicePathSize (TmpDevicePath);
    if ((Size == BufferSize) && CompareMem (DevicePath, TmpDevicePath, Size) == 0) {
      DriverHandle = Handle;
      break;
    }
  }
  FreePool (Handles);

  if (DriverHandle == NULL) {
    return NULL;
  }

  //
  // Retrieve all Hii Handles from HII database
  //
  BufferSize = 0x1000;
  HiiHandles = AllocatePool (BufferSize);
  ASSERT (HiiHandles != NULL);
  Status = gHiiDatabase->ListPackageLists (
                          gHiiDatabase,
                          EFI_HII_PACKAGE_TYPE_ALL,
                          NULL,
                          &BufferSize,
                          HiiHandles
                          );
  if (Status == EFI_BUFFER_TOO_SMALL) {
    FreePool (HiiHandles);
    HiiHandles = AllocatePool (BufferSize);
    ASSERT (HiiHandles != NULL);

    Status = gHiiDatabase->ListPackageLists (
                            gHiiDatabase,
                            EFI_HII_PACKAGE_TYPE_ALL,
                            NULL,
                            &BufferSize,
                            HiiHandles
                            );
  }

  if (EFI_ERROR (Status)) {
    FreePool (HiiHandles);
    return NULL;
  }

  //
  // Search Hii Handle by Driver Handle
  //
  HiiHandle = NULL;
  HandleCount = BufferSize / sizeof (EFI_HII_HANDLE);
  for (Index = 0; Index < HandleCount; Index++) {
    Status = gHiiDatabase->GetPackageListHandle (
                            gHiiDatabase,
                            HiiHandles[Index],
                            &Handle
                            );
    if (!EFI_ERROR (Status) && (Handle == DriverHandle)) {
      HiiHandle = HiiHandles[Index];
      break;
    }
  }

  FreePool (HiiHandles);
  return HiiHandle;
}

/**
  Exports the contents of one or all package lists in the HII database into a buffer.

  If Handle is not NULL and not a valid EFI_HII_HANDLE registered in the database, 
  then ASSERT.
  If PackageListHeader is NULL, then ASSERT.
  If PackageListSize is NULL, then ASSERT.

  @param  Handle                 The HII Handle.
  @param  PackageListHeader      A pointer to a buffer that will contain the results of 
                                 the export function.
  @param  PackageListSize        On output, the length of the buffer that is required for the exported data.

  @retval EFI_SUCCESS            Package exported.

  @retval EFI_OUT_OF_RESOURCES   Not enought memory to complete the operations.

**/
EFI_STATUS 
EFIAPI
HiiLibExportPackageLists (
  IN EFI_HII_HANDLE                    Handle,
  OUT EFI_HII_PACKAGE_LIST_HEADER      **PackageListHeader,
  OUT UINTN                            *PackageListSize
  )
{
  EFI_STATUS                       Status;
  UINTN                            Size;
  EFI_HII_PACKAGE_LIST_HEADER      *PackageListHdr;

  ASSERT (PackageListSize != NULL);
  ASSERT (PackageListHeader != NULL);

  if (Handle != NULL) {
    ASSERT (IsHiiHandleRegistered (Handle));
  }

  Size = 0;
  PackageListHdr = NULL;
  Status = gHiiDatabase->ExportPackageLists (
                                      gHiiDatabase,
                                      Handle,
                                      &Size,
                                      PackageListHdr
                                      );
  ASSERT_EFI_ERROR (Status != EFI_BUFFER_TOO_SMALL);
  
  if (Status == EFI_BUFFER_TOO_SMALL) {
    PackageListHdr = AllocateZeroPool (Size);
    
    if (PackageListHeader == NULL) {
      return EFI_OUT_OF_RESOURCES;
    } else {
      Status = gHiiDatabase->ExportPackageLists (
                                          gHiiDatabase,
                                          Handle,
                                          &Size,
                                          PackageListHdr
                                           );
    }
  }

  if (!EFI_ERROR (Status)) {
    *PackageListHeader = PackageListHdr;
    *PackageListSize   = Size;
  } else {
    FreePool (PackageListHdr);
  }

  return Status;
}

/**
  
  This function returns a list of the package handles of the   
  specified type that are currently active in the HII database. The   
  pseudo-type EFI_HII_PACKAGE_TYPE_ALL will cause all package   
  handles to be listed.

  If HandleBufferLength is NULL, then ASSERT.
  If HandleBuffer is NULL, the ASSERT.
  If PackageType is EFI_HII_PACKAGE_TYPE_GUID and PackageGuid is
  NULL, then ASSERT.
  If PackageType is not EFI_HII_PACKAGE_TYPE_GUID and PackageGuid is not
  NULL, then ASSERT.
  
  
  @param PackageType          Specifies the package type of the packages
                              to list or EFI_HII_PACKAGE_TYPE_ALL for
                              all packages to be listed.
  
  @param PackageGuid          If PackageType is
                              EFI_HII_PACKAGE_TYPE_GUID, then this is
                              the pointer to the GUID which must match
                              the Guid field of
                              EFI_HII_PACKAGE_GUID_HEADER. Otherwise, it
                              must be NULL.
  
  @param HandleBufferLength   On output, the length of the handle buffer
                              that is required for the handles found.

  @param HandleBuffer         On output, an array of EFI_HII_HANDLE  instances returned.
                              The caller is responcible to free this pointer allocated.

  @retval EFI_SUCCESS           The matching handles are outputed successfully.
                                HandleBufferLength is updated with the actual length.
  @retval EFI_OUT_OF_RESOURCES  Not enough resource to complete the operation.
  @retval EFI_NOT_FOUND         No matching handle could not be found in database.
**/
EFI_STATUS
EFIAPI
HiiLibListPackageLists (
  IN        UINT8                     PackageType,
  IN CONST  EFI_GUID                  *PackageGuid,
  IN OUT    UINTN                     *HandleBufferLength,
  OUT       EFI_HII_HANDLE            **HandleBuffer
  )
{
  EFI_STATUS          Status;
  
  ASSERT (HandleBufferLength != NULL);
  ASSERT (HandleBuffer != NULL);
  
  *HandleBufferLength = 0;
  *HandleBuffer       = NULL;

  if (PackageType == EFI_HII_PACKAGE_TYPE_GUID) {
    ASSERT (PackageGuid != NULL);
  } else {
    ASSERT (PackageGuid == NULL);
  }

  Status = gHiiDatabase->ListPackageLists (
                            gHiiDatabase,
                            PackageType,
                            PackageGuid,
                            HandleBufferLength,
                            *HandleBuffer
                            );
  if (EFI_ERROR (Status) && (Status != EFI_BUFFER_TOO_SMALL)) {
    //
    // No packages is registered to UEFI HII Database, just return.
    // 
    //
    return Status;
  }

  *HandleBuffer = AllocateZeroPool (*HandleBufferLength);
  
  if (*HandleBuffer == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }
  
  return gHiiDatabase->ListPackageLists (
                            gHiiDatabase,
                            PackageType,
                            PackageGuid,
                            HandleBufferLength,
                            *HandleBuffer
                            );
  
}
/**
  This function check if the Hii Handle is a valid handle registered
  in the HII database.

  @param HiiHandle The HII Handle.

  @retval TRUE If it is a valid HII handle.
  @retval FALSE If it is a invalid HII handle.
**/
BOOLEAN
IsHiiHandleRegistered (
  EFI_HII_HANDLE    HiiHandle
  )
{
  EFI_STATUS                   Status;
  UINTN                        BufferSize;
  EFI_HII_PACKAGE_LIST_HEADER  *HiiPackageList;

  ASSERT (HiiHandle != NULL);

  HiiPackageList = NULL;
  BufferSize = 0;

  Status = gHiiDatabase->ExportPackageLists (
             gHiiDatabase,
             HiiHandle,
             &BufferSize,
             HiiPackageList
             );

  return (BOOLEAN) (Status == EFI_BUFFER_TOO_SMALL);
}


/**
  Converts all hex dtring characters in range ['A'..'F'] to ['a'..'f'] for 
  hex digits that appear between a '=' and a '&' in a config string.

  If String is NULL, then ASSERT().

  @param[in] String  Pointer to a Null-terminated Unicode string.

  @return  Pointer to the Null-terminated Unicode result string.

**/
EFI_STRING
EFIAPI
InternalHiiLowerConfigString (
  IN EFI_STRING  ConfigString
  )
{
  EFI_STRING  String;
  BOOLEAN     Lower;

  ASSERT (ConfigString != NULL);

  //
  // Convert all hex digits in range [A-F] in the configuration header to [a-f]
  //
  for (String = ConfigString, Lower = FALSE; *String != L'\0'; String++) {
    if (*String == L'=') {
      Lower = TRUE;
    } else if (*String == L'&') {
      Lower = FALSE;
    } else if (Lower && *String >= L'A' && *String <= L'F') {
      *String = (CHAR16) (*String - L'A' + L'a');
    }
  }

  return ConfigString;
}

/**
  Uses the BlockToConfig() service of the Config Routing Protocol to 
  convert <ConfigRequest> and a buffer to a <ConfigResp>

  If ConfigRequest is NULL, then ASSERT().
  If Block is NULL, then ASSERT().

  @param[in] ConfigRequest  Pointer to a Null-terminated Unicode string.
  @param[in] Block          Pointer to a block of data.
  @param[in] BlockSize      The zie, in bytes, of Block.

  @retval NULL   The <ConfigResp> string could not be generated.
  @retval Other  Pointer to the Null-terminated Unicode <ConfigResp> string.

**/
EFI_STRING
EFIAPI
InternalHiiBlockToConfig (
  IN CONST EFI_STRING  ConfigRequest,
  IN CONST UINT8       *Block,
  IN UINTN             BlockSize
  )
{
  EFI_STATUS  Status;
  EFI_STRING  ConfigResp;
  CHAR16      *Progress;

  ASSERT (ConfigRequest != NULL);
  ASSERT (Block != NULL);

  //
  // Convert <ConfigRequest> to <ConfigResp>
  //
  Status = gHiiConfigRouting->BlockToConfig (
                                gHiiConfigRouting,
                                ConfigRequest,
                                Block,
                                BlockSize,
                                &ConfigResp,
                                &Progress
                                );
  if (EFI_ERROR (Status)) {
    return NULL;
  }
  return ConfigResp;
}

/**
  Uses the ConfigToBlock() service of the Config Routing Protocol to 
  convert <ConfigResp> to a block.  The block is allocated using
  AllocatePool().  The caller is responsible for freeing the block
  using FreePool().

  If ConfigResp is NULL, then ASSERT().

  @param[in] ConfigResp  Pointer to a Null-terminated Unicode string.
  @param[in] BufferSize  Length in bytes of buffer to hold retrived data. 

  @retval NULL   The block could not be generated..
  @retval Other  Pointer to the allocated block.

**/
UINT8 *
EFIAPI
InternalHiiConfigToBlock (
  IN  EFI_STRING  ConfigResp,
  IN  UINTN       BlockSize
  )
{
  EFI_STATUS  Status;
  CHAR16      *Progress;
  UINT8       *Block;

  ASSERT (ConfigResp != NULL);

  //
  // Allocate a buffer to hold the <ConfigResp> conversion
  //
  Block = AllocateZeroPool (BlockSize);
  if (Block == NULL) {
    return NULL;
  }

  //
  // Convert <ConfigResp> to a buffer
  //
  Status = gHiiConfigRouting->ConfigToBlock (
                                gHiiConfigRouting,
                                ConfigResp,
                                Block,
                                &BlockSize,
                                &Progress
                                );
  if (EFI_ERROR (Status)) {
    FreePool (Block);
    return NULL;
  }

  //
  // Return converted buffer
  //
  return Block;
}

/**
  Uses the BrowserCallback() service of the Form Browser Protocol to retrieve 
  or set uncommitted data.  If sata i being retrieved, then the buffer is 
  allocated using AllocatePool().  The caller is then responsible for freeing 
  the buffer using FreePool().

  @param[in]  VariableName    Pointer to a Null-terminated Unicode string.  This 
                              is an optional parameter that may be NULL.
  @param[in]  VariableGuid    Pointer to an EFI_GUID structure.  This is an optional 
                              parameter that may be NULL.
  @param[in]  SetResultsData  If not NULL, then this parameter specified the buffer
                              of uncommited data to set.  If this parameter is NULL,
                              then the caller is requesting to get the uncommited data
                              from the Form Browser.

  @retval NULL   The uncommitted data could not be retrieved.
  @retval Other  A pointer to a buffer containing the uncommitted data.

**/
EFI_STRING
EFIAPI
InternalHiiBrowserCallback (
  IN CONST EFI_GUID    *VariableGuid,  OPTIONAL
  IN CONST CHAR16      *VariableName,  OPTIONAL
  IN CONST EFI_STRING  SetResultsData  OPTIONAL
  )
{
  EFI_STATUS  Status;
  UINTN       ResultsDataSize;
  EFI_STRING  ResultsData;
  CHAR16      TempResultsData;

  //
  // Locate protocols
  //
  if (mUefiFormBrowser2 == NULL) {
    Status = gBS->LocateProtocol (&gEfiFormBrowser2ProtocolGuid, NULL, (VOID **) &mUefiFormBrowser2);
    if (EFI_ERROR (Status) || mUefiFormBrowser2 == NULL) {
      return NULL;
    }
  }

  ResultsDataSize = 0;

  if (SetResultsData != NULL) {
    //
    // Request to to set data in the uncommitted browser state information
    //
    ResultsData = SetResultsData;
  } else {
    //
    // Retrieve the length of the buffer required ResultsData from the Browser Callback
    //
    Status = mUefiFormBrowser2->BrowserCallback (
                              mUefiFormBrowser2,
                              &ResultsDataSize,
                              &TempResultsData,
                              TRUE,
                              VariableGuid,
                              VariableName
                              );
    if (Status != EFI_BUFFER_TOO_SMALL) {
      return NULL;
    }

    //
    // Allocate the ResultsData buffer
    //
    ResultsData = AllocateZeroPool (ResultsDataSize);
    if (ResultsData == NULL) {
      return NULL;
    }
  }

  //
  // Retrieve or set the ResultsData from the Browser Callback
  //
  Status = mUefiFormBrowser2->BrowserCallback (
                            mUefiFormBrowser2,
                            &ResultsDataSize,
                            ResultsData,
                            (BOOLEAN)(SetResultsData == NULL),
                            VariableGuid,
                            VariableName
                            );
  if (EFI_ERROR (Status)) {
    return NULL;
  }

  return ResultsData;
}

/**
  Allocates and returns a Null-terminated Unicode <ConfigHdr> string using routing 
  information that includes a GUID, an optional Unicode string name, and a device
  path.  The string returned is allocated with AllocatePool().  The caller is 
  responsible for freeing the allocated string with FreePool().
  
  The format of a <ConfigHdr> is as follows:

    GUID=<HexCh>32&NAME=<Char>NameLength&PATH=<HexChar>DevicePathSize<Null>

  @param[in]  Guid          Pointer to an EFI_GUID that is the routing information
                            GUID.  Each of the 16 bytes in Guid is converted to 
                            a 2 Unicode character hexidecimal string.  This is 
                            an optional parameter that may be NULL.
  @param[in]  Name          Pointer to a Null-terminated Unicode string that is 
                            the routing information NAME.  This is an optional 
                            parameter that may be NULL.  Each 16-bit Unicode 
                            character in Name is converted to a 4 character Unicode 
                            hexidecimal string.                        
  @param[in]  DriverHandle  The driver handle which supports a Device Path Protocol
                            that is the routing information PATH.  Each byte of
                            the Device Path associated with DriverHandle is converted
                            to a 2 Unicode character hexidecimal string.

  @retval NULL   DriverHandle does not support the Device Path Protocol.
  @retval Other  A pointer to the Null-terminate Unicode <ConfigHdr> string

**/
EFI_STRING
EFIAPI
HiiConstructConfigHdr (
  IN CONST EFI_GUID  *Guid,  OPTIONAL
  IN CONST CHAR16    *Name,  OPTIONAL
  IN EFI_HANDLE      DriverHandle
  )
{
  UINTN                     NameLength;
  EFI_DEVICE_PATH_PROTOCOL  *DevicePath;
  UINTN                     DevicePathSize;
  CHAR16                    *String;
  CHAR16                    *ReturnString;
  UINTN                     Index;
  UINT8                     *Buffer;

  //
  // Compute the length of Name in Unicode characters.  
  // If Name is NULL, then the length is 0.
  //
  NameLength = 0;
  if (Name != NULL) {
    NameLength = StrLen (Name);
  }

  DevicePath = NULL;
  DevicePathSize = 0;
  //
  // Retrieve DevicePath Protocol associated with DriverHandle
  //
  if (DriverHandle != NULL) {
    DevicePath = DevicePathFromHandle (DriverHandle);
    if (DevicePath == NULL) {
      return NULL;
    }
    //
    // Compute the size of the device path in bytes
    //
    DevicePathSize = GetDevicePathSize (DevicePath);
  }

  //
  // GUID=<HexCh>32&NAME=<Char>NameLength&PATH=<HexChar>DevicePathSize <Null>
  // | 5 | sizeof (EFI_GUID) * 2 | 6 | NameStrLen*4 | 6 | DevicePathSize * 2 | 1 |
  //
  String = AllocateZeroPool ((5 + sizeof (EFI_GUID) * 2 + 6 + NameLength * 4 + 6 + DevicePathSize * 2 + 1) * sizeof (CHAR16));
  if (String == NULL) {
    return NULL;
  }

  //
  // Start with L"GUID="
  //
  ReturnString = StrCpy (String, L"GUID=");
  String += StrLen (String);

  if (Guid != NULL) {
    //
    // Append Guid converted to <HexCh>32
    //
    for (Index = 0, Buffer = (UINT8 *)Guid; Index < sizeof (EFI_GUID); Index++) {
      String += UnicodeValueToString (String, PREFIX_ZERO | RADIX_HEX, *(Buffer++), 2);
    }
  }
  
  //
  // Append L"&NAME="
  //
  StrCpy (String, L"&NAME=");
  String += StrLen (String);

  if (Name != NULL) {
    //
    // Append Name converted to <Char>NameLength
    //
    for (; *Name != L'\0'; Name++) {
      String += UnicodeValueToString (String, PREFIX_ZERO | RADIX_HEX, *Name, 4);
    }
  }

  //
  // Append L"&PATH="
  //
  StrCpy (String, L"&PATH=");
  String += StrLen (String);

  //
  // Append the device path associated with DriverHandle converted to <HexChar>DevicePathSize
  //
  for (Index = 0, Buffer = (UINT8 *)DevicePath; Index < DevicePathSize; Index++) {
    String += UnicodeValueToString (String, PREFIX_ZERO | RADIX_HEX, *(Buffer++), 2);
  }

  //
  // Null terminate the Unicode string
  //
  *String = L'\0';

  //
  // Convert all hex digits in range [A-F] in the configuration header to [a-f]
  //
  return InternalHiiLowerConfigString (ReturnString);
}

/**
  Allocates and returns a Null-terminated Unicode <ConfigAltResp> string.

  If Guid is NULL, then ASSERT().
  If Name is NULL, then ASSERT().
  If BlockNameArray is NULL, then ASSERT().

  @param[in] Guid               GUID of the buffer storage.
  @param[in] Name               Name of the buffer storage.
  @param[in] DriverHandle       The DriverHandle that support a Device Path
                                Protocol.    
  @param[in] BufferStorage      Content of the buffer storage.
  @param[in] BufferStorageSize  Length in bytes of the buffer storage.
  @param[in] BlockNameArray     Array generated by VFR compiler.  This array
                                contains a UINT32 value that is the length
                                of BlockNameArray in bytes, followed by pairs
                                of 16-bit values that are the offset and length
                                values used to contruct a <ConfigRequest> string.
  @param[in]  ...               A variable argument list that contains pairs of 16-bit
                                ALTCFG identifiers and pointers to DefaultValueArrays.
                                The variable argument list is terminated by a NULL 
                                DefaultValueArray pointer.  A DefaultValueArray 
                                contains a UINT32 value that is the length, in bytes,
                                of the DefaultValueArray.  The UINT32 length value 
                                is followed by a series of records that contain
                                a 16-bit WIDTH value followed by a byte array with 
                                WIDTH entries.  The records must be parsed from
                                beginning to end until the UINT32 length limit
                                is reached.  

  @retval NULL          There are not enough resources to process the request.
  @retval NULL          A <ConfigResp> could not be retrieved from the Config 
                        Routing Protocol.
  @retval Other         A pointer to the Null-terminate Unicode <ConfigAltResp>
                        string.

**/
EFI_STRING
EFIAPI
HiiConstructConfigAltResp (
  IN CONST EFI_GUID  *Guid,
  IN CONST CHAR16    *Name,
  IN EFI_HANDLE      DriverHandle,
  IN CONST VOID      *BufferStorage,
  IN UINTN           BufferStorageSize,
  IN CONST VOID      *BlockNameArray, 
  ...
  )
{
  UINTN         Length;
  CHAR16        *String;
  CHAR16        *ConfigHdr;
  UINT8         *Buffer;
  UINT8         *BufferEnd;
  CHAR16        *ConfigRequest;
  EFI_STRING    ConfigResp;
  EFI_STRING    ConfigAltResp;
  VA_LIST       Args;
  UINTN         AltCfgId;
  UINT16        Width;
  UINT16        OffsetValue;
  UINT16        WidthValue;

  ASSERT (Guid != NULL);
  ASSERT (Name != NULL);
  ASSERT (BlockNameArray != NULL);

  //
  // Initialize local variables
  //
  ConfigHdr     = NULL;
  ConfigRequest = NULL; 
  ConfigResp    = NULL;

  //
  // Construct <ConfigHdr> : "GUID=...&NAME=...&PATH=..."
  //
  ConfigHdr = HiiConstructConfigHdr (Guid, Name, DriverHandle);
  if (ConfigHdr == NULL) {
    goto Exit;
  }

  //
  // Compute the length of the entire request starting with <ConfigHdr> and a 
  // Null-terminator
  //
  Length = StrLen (ConfigHdr) + 1;

  //
  // Determine the size <BlockName> Offset/Width pairs
  //
  Buffer = (UINT8 *)BlockNameArray;
  BufferEnd = Buffer + ReadUnaligned32 ((UINT32 *)Buffer);
  Buffer += sizeof (UINT32);

  //
  // Add <BlockName> length that is composed of one or more Offset/Width pairs
  //
  // <BlockName> ::= &OFFSET=1234&WIDTH=1234
  //                 |  8   | 4 |   7  | 4 |
  //
  Length += (((BufferEnd - Buffer) / (sizeof (UINT16) + sizeof (UINT16))) * (8 + 4 + 7 + 4));

  //
  // Allocate buffer for the entire <ConfigRequest>
  //
  ConfigRequest = AllocateZeroPool (Length * sizeof (CHAR16));
  if (ConfigRequest == NULL) {
    goto Exit;
  }
  String = ConfigRequest;

  //
  // Start with <ConfigHdr>
  //
  StrCpy (String, ConfigHdr);
  String += StrLen (String);

  //
  // Loop through all the Offset/Width pairs and append them to ConfigRequest
  //
  while (Buffer < BufferEnd) {
    //
    // Append &OFFSET=XXXX&WIDTH=YYYY
    //
    OffsetValue = ReadUnaligned16 ((UINT16 *)Buffer);
    WidthValue  = ReadUnaligned16 ((UINT16 *)(Buffer + sizeof (UINT16)));
    UnicodeSPrint (
      String, 
      (8 + 4 + 7 + 4) * sizeof (CHAR16), 
      L"&OFFSET=%04X&WIDTH=%04X", 
      OffsetValue, 
      WidthValue
    );

    String += StrLen (String);
    Buffer += (sizeof (UINT16) + sizeof (UINT16));
  }

  //
  // Get the <ConfigResp>
  //
  ConfigResp = InternalHiiBlockToConfig (ConfigRequest, BufferStorage, BufferStorageSize);
  if (ConfigResp == NULL) {
    goto Exit;
  }

  //
  // Compute the length of the entire response starting with <ConfigResp> and a 
  // Null-terminator
  //
  Length = StrLen (ConfigResp) + 1;

  //
  // Add the length associated with each pair of variable argument parameters
  //
  VA_START (Args, BlockNameArray);
  while (TRUE) {
    AltCfgId = VA_ARG (Args, UINT16);
    Buffer   = VA_ARG (Args, UINT8 *);
    if (Buffer == NULL) {
      break;
    }

    //
    // Add length for "&<ConfigHdr>&ALTCFG=XXXX"
    //                |1| StrLen (ConfigHdr) | 8 | 4 |
    //
    Length += (1 + StrLen (ConfigHdr) + 8 + 4);

    BufferEnd = Buffer + ReadUnaligned32 ((UINT32 *)Buffer);
    Buffer += sizeof (UINT32);
    while (Buffer < BufferEnd) {
      //
      // Extract Width field
      //
      Width = ReadUnaligned16 ((UINT16 *)(Buffer + sizeof (UINT16)));

      //
      // Add length for "&OFFSET=XXXX&WIDTH=YYYY&VALUE=zzzzzzzzzzzz"
      //                |    8  | 4 |   7  | 4 |   7  | Width * 2 |
      //
      Length += (8 + 4 + 7 + 4 + 7 + Width * 2);

      //
      // Update Buffer to the next record
      //
      Buffer += (sizeof (UINT16) + sizeof (UINT16) + Width);
    }
  }
  VA_END (Args);

  //
  // Allocate a buffer for the entire response
  //
  ConfigAltResp = AllocateZeroPool (Length * sizeof (CHAR16));
  if (ConfigAltResp == NULL) {
    goto Exit;
  }
  String = ConfigAltResp;

  //
  // Add <ConfigResp>
  //
  StrCpy (String, ConfigResp);
  String += StrLen (String);

  //
  // Add <AltResp> for each pair of variable argument parameters
  //
  VA_START (Args, BlockNameArray);
  while (TRUE) {
    AltCfgId = VA_ARG (Args, UINT16);
    Buffer   = VA_ARG (Args, UINT8 *);
    if (Buffer == NULL) {
      break;
    }

    //
    // Add <AltConfigHdr> of the form "&<ConfigHdr>&ALTCFG=XXXX"
    //                                |1| StrLen (ConfigHdr) | 8 | 4 |
    //
    UnicodeSPrint (
      String, 
      (1 + StrLen (ConfigHdr) + 8 + 4) * sizeof (CHAR16), 
      L"&%s&ALTCFG=%04X", 
      ConfigHdr, 
      AltCfgId
      );
    String += StrLen (String);

    //
    // Add <ConfigBody> ::= <ConfigElement>*
    //
    BufferEnd = Buffer + ReadUnaligned32 ((UINT32 *)Buffer);
    Buffer += sizeof (UINT32);
    while (Buffer < BufferEnd) {
      //
      // Extract Width field
      //
      Width = ReadUnaligned16 ((UINT16 *)(Buffer + sizeof (UINT16)));

      //
      // Add <BlockConfig>
      //
      UnicodeSPrint (
        String, 
        (8 + 4 + 7 + 4 + 7 + Width * 2) * sizeof (CHAR16),
        L"&OFFSET=%04X&WIDTH=%04X&VALUE=", 
        ReadUnaligned16 ((UINT16 *)Buffer), 
        Width
        );
      String += StrLen (String);

      //
      // Update Buffer to point to the value in the current record
      //
      Buffer += (sizeof (UINT16) + sizeof (UINT16));

      //
      // Convert Value to a hex string in "%x" format
      //   NOTE: This is in the opposite byte that GUID and PATH use
      //
      for (; Width > 0; Width--) {
        String += UnicodeValueToString (String, PREFIX_ZERO | RADIX_HEX, Buffer[Width - 1], 2);
      }
      //
      // Update Buffer to the next record
      //
      Buffer += Width;
    }
  }
  VA_END (Args);

  //
  // Convert all hex digits in range [A-F] in the configuration header to [a-f]
  //
  return InternalHiiLowerConfigString (ConfigAltResp);

Exit:
  if (ConfigHdr != NULL) {
    FreePool (ConfigHdr);
  }
  if (ConfigRequest != NULL) {
    FreePool (ConfigRequest);
  }
  if (ConfigResp != NULL) {
    FreePool (ConfigResp);
  }

  return NULL;
}

/**
  Determines if two values in config strings match.

  Compares the substring between StartSearchString and StopSearchString in 
  FirstString to the substring between StartSearchString and StopSearchString 
  in SecondString.  If the two substrings match, then TRUE is returned.  If the
  two substrings do not match, then FALSE is returned.

  If FirstString is NULL, then ASSERT().
  If SecondString is NULL, then ASSERT().
  If StartSearchString is NULL, then ASSERT().
  If StopSearchString is NULL, then ASSERT().

  @param FirstString        Pointer to the first Null-terminated Unicode string.
  @param SecondString       Pointer to the second Null-terminated Unicode string.
  @param StartSearchString  Pointer to the Null-terminated Unicode string that 
                            marks the start of the value string to compare.
  @param StopSearchString   Pointer to the Null-terminated Unicode string that 
                            marks the end of the vakue string to compare.

  @retval FALSE             StartSearchString is not present in FirstString. 
  @retval FALSE             StartSearchString is not present in SecondString.
  @retval FALSE             StopSearchString is not present in FirstString. 
  @retval FALSE             StopSearchString is not present in SecondString.
  @retval FALSE             The length of the substring in FirstString is not the 
                            same length as the substring in SecondString.
  @retval FALSE             The value string in FirstString does not matche the 
                            value string in SecondString.
  @retval TRUE              The value string in FirstString matches the value 
                            string in SecondString.

**/
BOOLEAN
EFIAPI
InternalHiiCompareSubString (
  IN CHAR16  *FirstString,
  IN CHAR16  *SecondString,
  IN CHAR16  *StartSearchString,
  IN CHAR16  *StopSearchString
  )
{
  CHAR16  *EndFirstString;
  CHAR16  *EndSecondString;

  ASSERT (FirstString != NULL);
  ASSERT (SecondString != NULL);
  ASSERT (StartSearchString != NULL);
  ASSERT (StopSearchString != NULL);

  FirstString = StrStr (FirstString, StartSearchString);
  if (FirstString == NULL) {
    return FALSE;
  }

  SecondString = StrStr (SecondString, StartSearchString);
  if (SecondString == NULL) {
    return FALSE;
  }

  EndFirstString = StrStr (FirstString, StopSearchString);
  if (EndFirstString == NULL) {
    return FALSE;
  }

  EndSecondString = StrStr (SecondString, StopSearchString);
  if (EndSecondString == NULL) {
    return FALSE;
  }

  if ((EndFirstString - FirstString) != (EndSecondString - SecondString)) {
    return FALSE;
  }

  return (BOOLEAN)(StrnCmp (FirstString, SecondString, EndFirstString - FirstString) == 0);
}

/**
  Determines if the routing data specified by GUID and NAME match a <ConfigHdr>.

  If ConfigHdr is NULL, then ASSERT().

  @param[in] ConfigHdr  Either <ConfigRequest> or <ConfigResp>.
  @param[in] Guid       GUID of the storage.
  @param[in] Name       NAME of the storage.

  @retval TRUE   Routing information matches <ConfigHdr>.
  @retval FALSE  Routing information does not match <ConfigHdr>.

**/
BOOLEAN
EFIAPI
HiiIsConfigHdrMatch (
  IN CONST EFI_STRING  ConfigHdr,
  IN CONST EFI_GUID    *Guid,     OPTIONAL
  IN CONST CHAR16      *Name      OPTIONAL
  )
{
  EFI_STRING  CompareConfigHdr;
  BOOLEAN     Result;

  ASSERT (ConfigHdr != NULL);

  //
  // Use Guid and Name to generate a <ConfigHdr> string
  //
  CompareConfigHdr = HiiConstructConfigHdr (Guid, Name, NULL);
  if (CompareConfigHdr == NULL) {
    return FALSE;
  }

  Result = TRUE;
  if (Guid != NULL) {
    //
    // Compare GUID value strings
    //
    Result = InternalHiiCompareSubString (ConfigHdr, CompareConfigHdr, L"GUID=", L"&NAME=");
  }

  if (Result && Name != NULL) {
    //
    // Compare NAME value strings
    //
    Result = InternalHiiCompareSubString (ConfigHdr, CompareConfigHdr, L"&NAME=", L"&PATH=");
  }

  //
  // Free the <ConfigHdr> string
  //
  FreePool (CompareConfigHdr);

  return Result;
}

/**
  Retrieves uncommited data from the Form Browser and converts it to a binary
  buffer.  The returned buffer is allocated using AllocatePool().  The caller
  is responsible for freeing the returned buffer using FreePool().

  @param[in]  VariableName  Pointer to a Null-terminated Unicode string.  This 
                            is an optional parameter that may be NULL.
  @param[in]  VariableGuid  Pointer to an EFI_GUID structure.  This is an optional 
                            parameter that may be NULL.
  @param[in]  BufferSize    Length in bytes of buffer to hold retrived data. 

  @retval NULL   The uncommitted data could not be retrieved.
  @retval Other  A pointer to a buffer containing the uncommitted data.

**/
UINT8 *
EFIAPI
HiiGetBrowserData (
  IN CONST EFI_GUID  *VariableGuid,  OPTIONAL
  IN CONST CHAR16    *VariableName,  OPTIONAL
  IN UINTN           BlockSize
  )
{
  EFI_STRING  ResultsData;
  UINTN       Size;
  EFI_STRING  ConfigResp;
  UINT8       *Block;

  //
  // Retrieve the results data from the Browser Callback
  //
  ResultsData = InternalHiiBrowserCallback (VariableGuid, VariableName, NULL);
  if (ResultsData == NULL) {
    return NULL;
  }

  //
  // Construct <ConfigResp> mConfigHdrTemplate L'&' ResultsData L'\0'
  //
  Size = (StrLen (mConfigHdrTemplate) + 1) * sizeof (CHAR16);
  Size = Size + (StrLen (ResultsData) + 1) * sizeof (CHAR16);
  ConfigResp = AllocateZeroPool (Size);
  UnicodeSPrint (ConfigResp, Size, L"%s&%s", mConfigHdrTemplate, ResultsData);
  
  //
  // Free the allocated buffer
  //
  FreePool (ResultsData);
  if (ConfigResp == NULL) {
    return NULL;
  }

  //
  // Convert <ConfigResp> to a buffer
  //
  Block = InternalHiiConfigToBlock (ConfigResp, BlockSize);
  FreePool (ConfigResp);

  return Block;
}

/**
  Updates uncommitted data in the Form Browser.

  If Buffer is NULL, then ASSERT().

  @param[in]  VariableName    Pointer to a Null-terminated Unicode string.  This
                              is an optional parameter that may be NULL.
  @param[in]  VariableGuid    Pointer to an EFI_GUID structure.  This is an optional
                              parameter that may be NULL.
  @param[in]  BufferSize      Length, in bytes, of Buffer.
  @param[in]  Buffer          Buffer of data to commit.
  @param[in]  RequestElement  An optional field to specify which part of the
                              buffer data will be send back to Browser. If NULL,
                              the whole buffer of data will be committed to
                              Browser. 
                              <RequestElement> ::= &OFFSET=<Number>&WIDTH=<Number>*

  @retval FALSE  The uncommitted data could not be updated.
  @retval TRUE   The uncommitted data was updated.

**/
BOOLEAN
EFIAPI
HiiSetBrowserData (
  IN CONST EFI_GUID  *VariableGuid, OPTIONAL
  IN CONST CHAR16    *VariableName, OPTIONAL
  IN UINTN           BufferSize,
  IN CONST UINT8     *Buffer,
  IN CONST CHAR16    *RequestElement  OPTIONAL
  )
{
  UINTN       Size;
  EFI_STRING  ConfigRequest;
  EFI_STRING  ConfigResp;
  EFI_STRING  ResultsData;

  ASSERT (Buffer != NULL);

  //
  // Construct <ConfigRequest>
  //
  if (RequestElement == NULL) {
    //
    // Allocate and fill a buffer large enough to hold the <ConfigHdr> template 
    // followed by "&OFFSET=0&WIDTH=WWWWWWWWWWWWWWWW" followed by a Null-terminator
    //
    Size = (StrLen (mConfigHdrTemplate) + 32 + 1) * sizeof (CHAR16);
    ConfigRequest = AllocateZeroPool (Size);
    UnicodeSPrint (ConfigRequest, Size, L"%s&OFFSET=0&WIDTH=%016LX", mConfigHdrTemplate, (UINT64)BufferSize);
  } else {
    //
    // Allocate and fill a buffer large enough to hold the <ConfigHdr> template 
    // followed by <RequestElement> followed by a Null-terminator
    //
    Size = StrLen (mConfigHdrTemplate) * sizeof (CHAR16);
    Size = Size + (StrLen (RequestElement) + 1) * sizeof (CHAR16);
    ConfigRequest = AllocateZeroPool (Size);
    UnicodeSPrint (ConfigRequest, Size, L"%s%s", mConfigHdrTemplate, RequestElement);
  }
  if (ConfigRequest == NULL) {
    return FALSE;
  }

  //
  // Convert <ConfigRequest> to <ConfigResp>
  //
  ConfigResp = InternalHiiBlockToConfig (ConfigRequest, Buffer, BufferSize);
  FreePool (ConfigRequest);
  if (ConfigResp == NULL) {
    return FALSE;
  }

  //
  // Set data in the uncommitted browser state information
  //
  ResultsData = InternalHiiBrowserCallback (VariableGuid, VariableName, ConfigResp + StrLen(mConfigHdrTemplate) + 1);
  FreePool (ConfigResp);

  return (BOOLEAN)(ResultsData != NULL);
}

/////////////////////////////////////////
/////////////////////////////////////////
/// IFR Functions
/////////////////////////////////////////
/////////////////////////////////////////

#define HII_LIB_OPCODE_ALLOCATION_SIZE  0x200

typedef struct {
  UINT8  *Buffer;
  UINTN  BufferSize;
  UINTN  Position;
} HII_LIB_OPCODE_BUFFER;

///
/// Lookup table that converts EFI_IFR_TYPE_X enum values to a width in bytes
///
GLOBAL_REMOVE_IF_UNREFERENCED CONST UINT8 mHiiDefaultTypeToWidth[] = {
  1, // EFI_IFR_TYPE_NUM_SIZE_8
  2, // EFI_IFR_TYPE_NUM_SIZE_16
  4, // EFI_IFR_TYPE_NUM_SIZE_32
  8, // EFI_IFR_TYPE_NUM_SIZE_64
  1, // EFI_IFR_TYPE_BOOLEAN
  3, // EFI_IFR_TYPE_TIME
  4, // EFI_IFR_TYPE_DATE
  2  // EFI_IFR_TYPE_STRING
};

/**
  Allocates and returns a new OpCode Handle.  OpCode Handles must be freed with 
  HiiFreeOpCodeHandle().

  @retval NULL   There are not enough resources to allocate a new OpCode Handle.
  @retval Other  A new OpCode handle.

**/
VOID *
EFIAPI
HiiAllocateOpCodeHandle (
  VOID
  )
{
  HII_LIB_OPCODE_BUFFER  *OpCodeBuffer;

  OpCodeBuffer = (HII_LIB_OPCODE_BUFFER *)AllocatePool (sizeof (HII_LIB_OPCODE_BUFFER));
  if (OpCodeBuffer == NULL) {
    return NULL;
  }
  OpCodeBuffer->Buffer = (UINT8 *)AllocatePool (HII_LIB_OPCODE_ALLOCATION_SIZE);
  if (OpCodeBuffer->Buffer == NULL) {
    FreePool (OpCodeBuffer);
    return NULL;
  }
  OpCodeBuffer->BufferSize = HII_LIB_OPCODE_ALLOCATION_SIZE;
  OpCodeBuffer->Position = 0;
  return (VOID *)OpCodeBuffer;
}

/**
  Frees an OpCode Handle that was peviously allocated with HiiAllocateOpCodeHandle().
  When an OpCode Handle is freed, all of the opcodes associated with the OpCode
  Handle are also freed.

  If OpCodeHandle is NULL, then ASSERT().

**/
VOID
EFIAPI
HiiFreeOpCodeHandle (
  VOID  *OpCodeHandle
  )
{
  HII_LIB_OPCODE_BUFFER  *OpCodeBuffer;

  ASSERT (OpCodeHandle != NULL);

  OpCodeBuffer = (HII_LIB_OPCODE_BUFFER *)OpCodeHandle;
  if (OpCodeBuffer->Buffer != NULL) {
    FreePool (OpCodeBuffer->Buffer);
  }
  FreePool (OpCodeBuffer);
}

UINTN
EFIAPI
InternalHiiOpCodeHandlePosition (
  IN VOID  *OpCodeHandle
  )
{
  return ((HII_LIB_OPCODE_BUFFER  *)OpCodeHandle)->Position;
}

UINT8 *
EFIAPI
InternalHiiOpCodeHandleBuffer (
  IN VOID  *OpCodeHandle
  )
{
  return ((HII_LIB_OPCODE_BUFFER  *)OpCodeHandle)->Buffer;
}

UINT8 *
EFIAPI
InternalHiiGrowOpCodeHandle (
  VOID   *OpCodeHandle,
  UINTN  Size
  )
{
  HII_LIB_OPCODE_BUFFER  *OpCodeBuffer;
  UINT8                  *Buffer;

  ASSERT (OpCodeHandle != NULL);

  OpCodeBuffer = (HII_LIB_OPCODE_BUFFER *)OpCodeHandle;
  if (OpCodeBuffer->Position + Size > OpCodeBuffer->BufferSize) {
    Buffer = ReallocatePool (
              OpCodeBuffer->BufferSize, 
              OpCodeBuffer->BufferSize + (Size + HII_LIB_OPCODE_ALLOCATION_SIZE),
              OpCodeBuffer->Buffer
              );
    if (Buffer == NULL) {
      return NULL;
    }
    OpCodeBuffer->Buffer = Buffer;
    OpCodeBuffer->BufferSize += (Size + HII_LIB_OPCODE_ALLOCATION_SIZE);
  }
  Buffer = OpCodeBuffer->Buffer + OpCodeBuffer->Position;
  OpCodeBuffer->Position += Size;
  return Buffer;
}

UINT8 *
EFIAPI
InternalHiiCreateOpCodeExtended (
  IN VOID   *OpCodeHandle,
  IN VOID   *OpCodeTemplate,
  IN UINT8  OpCode,
  IN UINTN  OpCodeSize,
  IN UINTN  ExtensionSize,
  IN UINT8  Scope
  )
{
  EFI_IFR_OP_HEADER  *Header;
  UINT8              *Buffer;

  ASSERT (OpCodeTemplate != NULL);
  ASSERT ((OpCodeSize + ExtensionSize) <= 0x7F);

  Header = (EFI_IFR_OP_HEADER *)OpCodeTemplate;
  Header->OpCode = OpCode;
  Header->Scope  = Scope;
  Header->Length = (UINT8)(OpCodeSize + ExtensionSize);
  Buffer = InternalHiiGrowOpCodeHandle (OpCodeHandle, Header->Length);
  return (UINT8 *)CopyMem (Buffer, Header, OpCodeSize);
}

UINT8 *
EFIAPI
InternalHiiCreateOpCode (
  IN VOID   *OpCodeHandle,
  IN VOID   *OpCodeTemplate,
  IN UINT8  OpCode,
  IN UINTN  OpCodeSize
  )
{
  return InternalHiiCreateOpCodeExtended (OpCodeHandle, OpCodeTemplate, OpCode, OpCodeSize, 0, 0);
}

/**
  Append raw opcodes to an OpCodeHandle.

  If OpCodeHandle is NULL, then ASSERT().
  If RawBuffer is NULL, then ASSERT();

  @param[in]  OpCodeHandle   Handle to the buffer of opcodes.
  @param[in]  RawBuffer      Buffer of opcodes to append.
  @param[in]  RawBufferSize  The size, in bytes, of Buffer.

  @retval NULL   There is not enough space left in Buffer to add the opcode.
  @retval Other  A pointer to the appended opcodes.

**/
UINT8 *
EFIAPI
InternalHiiCreateRawOpCodes (
  IN VOID   *OpCodeHandle,
  IN UINT8  *RawBuffer,
  IN UINTN  RawBufferSize
  )
{
  UINT8  *Buffer;

  ASSERT (RawBuffer != NULL);

  Buffer = InternalHiiGrowOpCodeHandle (OpCodeHandle, RawBufferSize);
  return (UINT8 *)CopyMem (Buffer, RawBuffer, RawBufferSize);
}

/**
  Append opcodes from one OpCode Handle to another OpCode handle.

  If OpCodeHandle is NULL, then ASSERT().
  If RawOpCodeHandle is NULL, then ASSERT();

  @param[in]  OpCodeHandle     Handle to the buffer of opcodes.
  @param[in]  RawOpCodeHandle  Handle to the buffer of opcodes.

  @retval NULL   There is not enough space left in Buffer to add the opcode.
  @retval Other  A pointer to the appended opcodes.

**/
UINT8 *
EFIAPI
InternalHiiAppendOpCodes (
  IN VOID  *OpCodeHandle,
  IN VOID  *RawOpCodeHandle
  )
{
  HII_LIB_OPCODE_BUFFER  *RawOpCodeBuffer;

  ASSERT (RawOpCodeHandle != NULL);

  RawOpCodeBuffer = (HII_LIB_OPCODE_BUFFER *)RawOpCodeHandle;
  return InternalHiiCreateRawOpCodes (OpCodeHandle, RawOpCodeBuffer->Buffer, RawOpCodeBuffer->Position);
}

/**
  Create EFI_IFR_END_OP opcode.

  If OpCodeHandle is NULL, then ASSERT().

  @param[in]  OpCodeHandle  Handle to the buffer of opcodes.

  @retval NULL   There is not enough space left in Buffer to add the opcode.
  @retval Other  A pointer to the created opcode.

**/
UINT8 *
EFIAPI
HiiCreateEndOpCode (
  IN VOID  *OpCodeHandle
  )
{
  EFI_IFR_END  OpCode;

  return InternalHiiCreateOpCode (OpCodeHandle, &OpCode, EFI_IFR_END_OP, sizeof (OpCode));
}

/**
  Create EFI_IFR_ONE_OF_OPTION_OP opcode.

  If OpCodeHandle is NULL, then ASSERT().
  If Type is invalid, then ASSERT().
  If Flags is invalid, then ASSERT().

  @param[in]  OpCodeHandle  Handle to the buffer of opcodes.
  @param[in]  StringId      StringId for the option
  @param[in]  Flags         Flags for the option
  @param[in]  Type          Type for the option
  @param[in]  Value         Value for the option

  @retval NULL   There is not enough space left in Buffer to add the opcode.
  @retval Other  A pointer to the created opcode.

**/
UINT8 *
EFIAPI
HiiCreateOneOfOptionOpCode (
  IN VOID    *OpCodeHandle,
  IN UINT16  StringId,
  IN UINT8   Flags,
  IN UINT8   Type,
  IN UINT64  Value
  )
{
  EFI_IFR_ONE_OF_OPTION  OpCode;

  ASSERT (Type < EFI_IFR_TYPE_OTHER);

  ZeroMem (&OpCode, sizeof (OpCode));
  OpCode.Option = StringId;
  OpCode.Flags  = (UINT8) (Flags & (EFI_IFR_OPTION_DEFAULT | EFI_IFR_OPTION_DEFAULT_MFG));
  OpCode.Type   = Type;
  CopyMem (&OpCode.Value, &Value, mHiiDefaultTypeToWidth[Type]);

  return InternalHiiCreateOpCode (OpCodeHandle, &OpCode, EFI_IFR_ONE_OF_OPTION_OP, sizeof (OpCode));
}

/**
  Create EFI_IFR_DEFAULT_OP opcode.

  If OpCodeHandle is NULL, then ASSERT().
  If Type is invalid, then ASSERT().

  @param[in]  OpCodeHandle  Handle to the buffer of opcodes.
  @param[in]  DefaultId     DefaultId for the default
  @param[in]  Type          Type for the default
  @param[in]  Value         Value for the default

  @retval NULL   There is not enough space left in Buffer to add the opcode.
  @retval Other  A pointer to the created opcode.

**/
UINT8 *
EFIAPI
HiiCreateDefaultOpCode (
  IN VOID    *OpCodeHandle,
  IN UINT16  DefaultId,
  IN UINT8   Type,
  IN UINT64  Value
  )
{
  EFI_IFR_DEFAULT  OpCode;

  ASSERT (Type < EFI_IFR_TYPE_OTHER);

  ZeroMem (&OpCode, sizeof (OpCode));
  OpCode.Type      = Type;
  OpCode.DefaultId = DefaultId;
  CopyMem (&OpCode.Value, &Value, mHiiDefaultTypeToWidth[Type]);

  return InternalHiiCreateOpCode (OpCodeHandle, &OpCode, EFI_IFR_DEFAULT_OP, sizeof (OpCode));
}

/**
  Create EFI_IFR_GUID opcode.

  If OpCodeHandle is NULL, then ASSERT().
  If Guid is NULL, then ASSERT().
  If OpCodeSize < sizeof (EFI_IFR_GUID), then ASSERT().

  @param[in]  OpCodeHandle  Handle to the buffer of opcodes.
  @param[in]  Guid          Pointer to EFI_GUID of this guided opcode.
  @param[in]  GuidOpCode    Pointer to an EFI_IFR_GUID opcode.  This is an 
                            optional parameter that may be NULL.  If this
                            parameter is NULL, then the GUID extension 
                            region of the created opcode is filled with zeros.
                            If this parameter is not NULL, then the GUID 
                            extension region of GuidData will be copied to 
                            the GUID extension region of the created opcode.
  @param[in]  OpCodeSize    The size, in bytes, of created opcode.  This value 
                            must be >= sizeof(EFI_IFR_GUID).

  @retval NULL   There is not enough space left in Buffer to add the opcode.
  @retval Other  A pointer to the created opcode.

**/
UINT8 *
EFIAPI
HiiCreateGuidOpCode (
  IN VOID            *OpCodeHandle,
  IN CONST EFI_GUID  *Guid,
  IN CONST VOID      *GuidOpCode,    OPTIONAL
  IN UINTN           OpCodeSize
  )
{
  EFI_IFR_GUID  OpCode;
  EFI_IFR_GUID  *OpCodePointer;

  ASSERT (Guid != NULL);
  ASSERT (OpCodeSize >= sizeof (OpCode));

  ZeroMem (&OpCode, sizeof (OpCode));
  CopyGuid ((EFI_GUID *)(VOID *)&OpCode.Guid, Guid);

  OpCodePointer = (EFI_IFR_GUID *)InternalHiiCreateOpCodeExtended (
                                    OpCodeHandle, 
                                    &OpCode,
                                    EFI_IFR_GUID_OP,
                                    sizeof (OpCode),
                                    OpCodeSize - sizeof (OpCode),
                                    0
                                    );
  if (OpCodePointer != NULL && GuidOpCode != NULL) {
    CopyMem (OpCodePointer + 1, (EFI_IFR_GUID *)GuidOpCode + 1, OpCodeSize - sizeof (OpCode));
  }
  return (UINT8 *)OpCodePointer;
}

/**
  Create EFI_IFR_ACTION_OP opcode.

  If OpCodeHandle is NULL, then ASSERT().
  If any reserved bits are set in QuestionFlags, then ASSERT().

  @param[in]  OpCodeHandle  Handle to the buffer of opcodes.
  @param[in]  QuestionId      Question ID
  @param[in]  Prompt          String ID for Prompt
  @param[in]  Help            String ID for Help
  @param[in]  QuestionFlags   Flags in Question Header
  @param[in]  QuestionConfig  String ID for configuration

  @retval NULL   There is not enough space left in Buffer to add the opcode.
  @retval Other  A pointer to the created opcode.

**/
UINT8 *
EFIAPI
HiiCreateActionOpCode (
  IN VOID             *OpCodeHandle,
  IN EFI_QUESTION_ID  QuestionId,
  IN EFI_STRING_ID    Prompt,
  IN EFI_STRING_ID    Help,
  IN UINT8            QuestionFlags,
  IN EFI_STRING_ID    QuestionConfig
  )
{
  EFI_IFR_ACTION  OpCode;

  ASSERT ((QuestionFlags & (~(EFI_IFR_FLAG_READ_ONLY | EFI_IFR_FLAG_CALLBACK | EFI_IFR_FLAG_RESET_REQUIRED | EFI_IFR_FLAG_OPTIONS_ONLY))) == 0);

  ZeroMem (&OpCode, sizeof (OpCode));
  OpCode.Question.QuestionId    = QuestionId;
  OpCode.Question.Header.Prompt = Prompt;
  OpCode.Question.Header.Help   = Help;
  OpCode.Question.Flags         = QuestionFlags;
  OpCode.QuestionConfig         = QuestionConfig;

  return InternalHiiCreateOpCode (OpCodeHandle, &OpCode, EFI_IFR_ACTION_OP, sizeof (OpCode));
}

/**
  Create EFI_IFR_SUBTITLE_OP opcode.

  If OpCodeHandle is NULL, then ASSERT().
  If any reserved bits are set in Flags, then ASSERT().
  If Scope > 1, then ASSERT().

  @param[in]  OpCodeHandle  Handle to the buffer of opcodes.
  @param[in]  Prompt      String ID for Prompt
  @param[in]  Help        String ID for Help
  @param[in]  Flags       Subtitle opcode flags
  @param[in]  Scope       1 if this opcpde is the beginning of a new scope.
                          0 if this opcode is within the current scope.

  @retval NULL   There is not enough space left in Buffer to add the opcode.
  @retval Other  A pointer to the created opcode.

**/
UINT8 *
EFIAPI
HiiCreateSubTitleOpCode (
  IN VOID           *OpCodeHandle,
  IN EFI_STRING_ID  Prompt,
  IN EFI_STRING_ID  Help,
  IN UINT8          Flags,
  IN UINT8          Scope
  )
{
  EFI_IFR_SUBTITLE  OpCode;

  ASSERT (Scope <= 1);
  ASSERT ((Flags & (~(EFI_IFR_FLAGS_HORIZONTAL))) == 0);

  ZeroMem (&OpCode, sizeof (OpCode));
  OpCode.Statement.Prompt = Prompt;
  OpCode.Statement.Help   = Help;
  OpCode.Flags            = Flags;

  return InternalHiiCreateOpCodeExtended (
           OpCodeHandle, 
           &OpCode,
           EFI_IFR_SUBTITLE_OP, 
           sizeof (OpCode), 
           0, 
           Scope
           );
}

/**
  Create EFI_IFR_REF_OP opcode.

  If OpCodeHandle is NULL, then ASSERT().
  If any reserved bits are set in QuestionFlags, then ASSERT().

  @param[in]  OpCodeHandle   Handle to the buffer of opcodes.
  @param[in]  FormId         Destination Form ID
  @param[in]  Prompt         String ID for Prompt
  @param[in]  Help           String ID for Help
  @param[in]  QuestionFlags  Flags in Question Header
  @param[in]  QuestionId     Question ID

  @retval NULL   There is not enough space left in Buffer to add the opcode.
  @retval Other  A pointer to the created opcode.

**/
UINT8 *
EFIAPI
HiiCreateGotoOpCode (
  IN VOID             *OpCodeHandle,
  IN EFI_FORM_ID      FormId,
  IN EFI_STRING_ID    Prompt,
  IN EFI_STRING_ID    Help,
  IN UINT8            QuestionFlags,
  IN EFI_QUESTION_ID  QuestionId
  )
{
  EFI_IFR_REF  OpCode;

  ASSERT ((QuestionFlags & (~(EFI_IFR_FLAG_READ_ONLY | EFI_IFR_FLAG_CALLBACK | EFI_IFR_FLAG_RESET_REQUIRED | EFI_IFR_FLAG_OPTIONS_ONLY))) == 0);

  ZeroMem (&OpCode, sizeof (OpCode));
  OpCode.Question.Header.Prompt = Prompt;
  OpCode.Question.Header.Help   = Help;
  OpCode.Question.QuestionId    = QuestionId;
  OpCode.Question.Flags         = QuestionFlags;
  OpCode.FormId                 = FormId;

  return InternalHiiCreateOpCode (OpCodeHandle, &OpCode, EFI_IFR_REF_OP, sizeof (OpCode));
}

/**
  Create EFI_IFR_CHECKBOX_OP opcode.

  If OpCodeHandle is NULL, then ASSERT().
  If any reserved bits are set in QuestionFlags, then ASSERT().
  If any reserved bits are set in CheckBoxFlags, then ASSERT().

  @param[in]  OpCodeHandle          Handle to the buffer of opcodes.
  @param[in]  QuestionId            Question ID
  @param[in]  VarStoreId            Storage ID
  @param[in]  VarOffset             Offset in Storage
  @param[in]  Prompt                String ID for Prompt
  @param[in]  Help                  String ID for Help
  @param[in]  QuestionFlags         Flags in Question Header
  @param[in]  CheckBoxFlags         Flags for checkbox opcode
  @param[in]  DefaultsOpCodeHandle  Handle for a buffer of DEFAULT opcodes.  This
                                    is an optional parameter that may be NULL.

  @retval NULL   There is not enough space left in Buffer to add the opcode.
  @retval Other  A pointer to the created opcode.

**/
UINT8 *
EFIAPI
HiiCreateCheckBoxOpCode (
  IN VOID             *OpCodeHandle,
  IN EFI_QUESTION_ID  QuestionId,
  IN EFI_VARSTORE_ID  VarStoreId,
  IN UINT16           VarOffset,
  IN EFI_STRING_ID    Prompt,
  IN EFI_STRING_ID    Help,
  IN UINT8            QuestionFlags,
  IN UINT8            CheckBoxFlags,
  IN VOID             *DefaultsOpCodeHandle  OPTIONAL
  )
{
  EFI_IFR_CHECKBOX  OpCode;
  UINTN             Position;

  ASSERT ((QuestionFlags & (~(EFI_IFR_FLAG_READ_ONLY | EFI_IFR_FLAG_CALLBACK | EFI_IFR_FLAG_RESET_REQUIRED | EFI_IFR_FLAG_OPTIONS_ONLY))) == 0);

  ZeroMem (&OpCode, sizeof (OpCode));
  OpCode.Question.QuestionId             = QuestionId;
  OpCode.Question.VarStoreId             = VarStoreId;
  OpCode.Question.VarStoreInfo.VarOffset = VarOffset;
  OpCode.Question.Header.Prompt          = Prompt;
  OpCode.Question.Header.Help            = Help;
  OpCode.Question.Flags                  = QuestionFlags;
  OpCode.Flags                           = CheckBoxFlags;

  if (DefaultsOpCodeHandle == NULL) {
    return InternalHiiCreateOpCode (OpCodeHandle, &OpCode, EFI_IFR_CHECKBOX_OP, sizeof (OpCode));
  }

  Position = InternalHiiOpCodeHandlePosition (OpCodeHandle);
  InternalHiiCreateOpCodeExtended (OpCodeHandle, &OpCode, EFI_IFR_CHECKBOX_OP, sizeof (OpCode), 0, 1);
  InternalHiiAppendOpCodes (OpCodeHandle, DefaultsOpCodeHandle);
  HiiCreateEndOpCode (OpCodeHandle);
  return InternalHiiOpCodeHandleBuffer (OpCodeHandle) + Position;
}

/**
  Create EFI_IFR_NUMERIC_OP opcode.

  If OpCodeHandle is NULL, then ASSERT().
  If any reserved bits are set in QuestionFlags, then ASSERT().
  If any reserved bits are set in NumericFlags, then ASSERT().

  @param[in]  OpCodeHandle          Handle to the buffer of opcodes.
  @param[in]  QuestionId            Question ID
  @param[in]  VarStoreId            Storage ID
  @param[in]  VarOffset             Offset in Storage
  @param[in]  Prompt                String ID for Prompt
  @param[in]  Help                  String ID for Help
  @param[in]  QuestionFlags         Flags in Question Header
  @param[in]  NumericFlags          Flags for numeric opcode
  @param[in]  Minimum               Numeric minimum value
  @param[in]  Maximum               Numeric maximum value
  @param[in]  Step                  Numeric step for edit
  @param[in]  DefaultsOpCodeHandle  Handle for a buffer of DEFAULT opcodes.  This
                                    is an optional parameter that may be NULL.

  @retval NULL   There is not enough space left in Buffer to add the opcode.
  @retval Other  A pointer to the created opcode.

**/
UINT8 *
EFIAPI
HiiCreateNumericOpCode (
  IN VOID             *OpCodeHandle,
  IN EFI_QUESTION_ID  QuestionId,
  IN EFI_VARSTORE_ID  VarStoreId,
  IN UINT16           VarOffset,
  IN EFI_STRING_ID    Prompt,
  IN EFI_STRING_ID    Help,
  IN UINT8            QuestionFlags,
  IN UINT8            NumericFlags,
  IN UINT64           Minimum,
  IN UINT64           Maximum,
  IN UINT64           Step,
  IN VOID             *DefaultsOpCodeHandle  OPTIONAL
  )
{
  EFI_IFR_NUMERIC  OpCode;
  UINTN            Position;

  ASSERT ((QuestionFlags & (~(EFI_IFR_FLAG_READ_ONLY | EFI_IFR_FLAG_CALLBACK | EFI_IFR_FLAG_RESET_REQUIRED | EFI_IFR_FLAG_OPTIONS_ONLY))) == 0);

  ZeroMem (&OpCode, sizeof (OpCode));
  OpCode.Question.QuestionId             = QuestionId;
  OpCode.Question.VarStoreId             = VarStoreId;
  OpCode.Question.VarStoreInfo.VarOffset = VarOffset;
  OpCode.Question.Header.Prompt          = Prompt;
  OpCode.Question.Header.Help            = Help;
  OpCode.Question.Flags                  = QuestionFlags;
  OpCode.Flags                           = NumericFlags;

  switch (NumericFlags & EFI_IFR_NUMERIC_SIZE) {
  case EFI_IFR_NUMERIC_SIZE_1:
    OpCode.data.u8.MinValue = (UINT8)Minimum;
    OpCode.data.u8.MaxValue = (UINT8)Maximum;
    OpCode.data.u8.Step     = (UINT8)Step;
    break;

  case EFI_IFR_NUMERIC_SIZE_2:
    OpCode.data.u16.MinValue = (UINT16)Minimum;
    OpCode.data.u16.MaxValue = (UINT16)Maximum;
    OpCode.data.u16.Step     = (UINT16)Step;
    break;

  case EFI_IFR_NUMERIC_SIZE_4:
    OpCode.data.u32.MinValue = (UINT32)Minimum;
    OpCode.data.u32.MaxValue = (UINT32)Maximum;
    OpCode.data.u32.Step     = (UINT32)Step;
    break;

  case EFI_IFR_NUMERIC_SIZE_8:
    OpCode.data.u64.MinValue = Minimum;
    OpCode.data.u64.MaxValue = Maximum;
    OpCode.data.u64.Step     = Step;
    break;
  }

  if (DefaultsOpCodeHandle == NULL) {
    return InternalHiiCreateOpCode (OpCodeHandle, &OpCode, EFI_IFR_NUMERIC_OP, sizeof (OpCode));
  }

  Position = InternalHiiOpCodeHandlePosition (OpCodeHandle);
  InternalHiiCreateOpCodeExtended (OpCodeHandle, &OpCode, EFI_IFR_NUMERIC_OP, sizeof (OpCode), 0, 1);
  InternalHiiAppendOpCodes (OpCodeHandle, DefaultsOpCodeHandle);
  HiiCreateEndOpCode (OpCodeHandle);
  return InternalHiiOpCodeHandleBuffer (OpCodeHandle) + Position;
}

/**
  Create EFI_IFR_STRING_OP opcode.

  If OpCodeHandle is NULL, then ASSERT().
  If any reserved bits are set in QuestionFlags, then ASSERT().
  If any reserved bits are set in StringFlags, then ASSERT().

  @param[in]  OpCodeHandle          Handle to the buffer of opcodes.
  @param[in]  QuestionId            Question ID
  @param[in]  VarStoreId            Storage ID
  @param[in]  VarOffset             Offset in Storage
  @param[in]  Prompt                String ID for Prompt
  @param[in]  Help                  String ID for Help
  @param[in]  QuestionFlags         Flags in Question Header
  @param[in]  StringFlags           Flags for string opcode
  @param[in]  MinSize               String minimum length
  @param[in]  MaxSize               String maximum length
  @param[in]  DefaultsOpCodeHandle  Handle for a buffer of DEFAULT opcodes.  This
                                    is an optional parameter that may be NULL.

  @retval NULL   There is not enough space left in Buffer to add the opcode.
  @retval Other  A pointer to the created opcode.

**/
UINT8 *
EFIAPI
HiiCreateStringOpCode (
  IN VOID             *OpCodeHandle,
  IN EFI_QUESTION_ID  QuestionId,
  IN EFI_VARSTORE_ID  VarStoreId,
  IN UINT16           VarOffset,
  IN EFI_STRING_ID    Prompt,
  IN EFI_STRING_ID    Help,
  IN UINT8            QuestionFlags,
  IN UINT8            StringFlags,
  IN UINT8            MinSize,
  IN UINT8            MaxSize,
  IN VOID             *DefaultsOpCodeHandle  OPTIONAL
  )
{
  EFI_IFR_STRING  OpCode;
  UINTN           Position;

  ASSERT ((QuestionFlags & (~(EFI_IFR_FLAG_READ_ONLY | EFI_IFR_FLAG_CALLBACK | EFI_IFR_FLAG_RESET_REQUIRED | EFI_IFR_FLAG_OPTIONS_ONLY))) == 0);

  ZeroMem (&OpCode, sizeof (OpCode));
  OpCode.Question.Header.Prompt          = Prompt;
  OpCode.Question.Header.Help            = Help;
  OpCode.Question.QuestionId             = QuestionId;
  OpCode.Question.VarStoreId             = VarStoreId;
  OpCode.Question.VarStoreInfo.VarOffset = VarOffset;
  OpCode.Question.Flags                  = QuestionFlags;
  OpCode.MinSize                         = MinSize;
  OpCode.MaxSize                         = MaxSize;
  OpCode.Flags                           = (UINT8) (StringFlags & EFI_IFR_STRING_MULTI_LINE);

  if (DefaultsOpCodeHandle == NULL) {
    return InternalHiiCreateOpCode (OpCodeHandle, &OpCode, EFI_IFR_STRING_OP, sizeof (OpCode));
  }

  Position = InternalHiiOpCodeHandlePosition (OpCodeHandle);
  InternalHiiCreateOpCodeExtended (OpCodeHandle, &OpCode, EFI_IFR_STRING_OP, sizeof (OpCode), 0, 1);
  InternalHiiAppendOpCodes (OpCodeHandle, DefaultsOpCodeHandle);
  HiiCreateEndOpCode (OpCodeHandle);
  return InternalHiiOpCodeHandleBuffer (OpCodeHandle) + Position;
}

/**
  Create EFI_IFR_ONE_OF_OP opcode.

  If OpCodeHandle is NULL, then ASSERT().
  If any reserved bits are set in QuestionFlags, then ASSERT().
  If any reserved bits are set in OneOfFlags, then ASSERT().

  @param[in]  OpCodeHandle          Handle to the buffer of opcodes.
  @param[in]  QuestionId            Question ID
  @param[in]  VarStoreId            Storage ID
  @param[in]  VarOffset             Offset in Storage
  @param[in]  Prompt                String ID for Prompt
  @param[in]  Help                  String ID for Help
  @param[in]  QuestionFlags         Flags in Question Header
  @param[in]  OneOfFlags            Flags for oneof opcode
  @param[in]  OptionsOpCodeHandle   Handle for a buffer of ONE_OF_OPTION opcodes.
  @param[in]  DefaultsOpCodeHandle  Handle for a buffer of DEFAULT opcodes.  This
                                    is an optional parameter that may be NULL.

  @retval NULL   There is not enough space left in Buffer to add the opcode.
  @retval Other  A pointer to the created opcode.

**/
UINT8 *
EFIAPI
HiiCreateOneOfOpCode (
  IN VOID             *OpCodeHandle,
  IN EFI_QUESTION_ID  QuestionId,
  IN EFI_VARSTORE_ID  VarStoreId,
  IN UINT16           VarOffset,
  IN EFI_STRING_ID    Prompt,
  IN EFI_STRING_ID    Help,
  IN UINT8            QuestionFlags,
  IN UINT8            OneOfFlags,
  IN VOID             *OptionsOpCodeHandle,
  IN VOID             *DefaultsOpCodeHandle  OPTIONAL
  )
{
  EFI_IFR_ONE_OF  OpCode;
  UINTN           Position;

  ASSERT (OptionsOpCodeHandle != NULL);
  ASSERT ((QuestionFlags & (~(EFI_IFR_FLAG_READ_ONLY | EFI_IFR_FLAG_CALLBACK | EFI_IFR_FLAG_RESET_REQUIRED | EFI_IFR_FLAG_OPTIONS_ONLY))) == 0);

  ZeroMem (&OpCode, sizeof (OpCode));
  OpCode.Question.Header.Prompt          = Prompt;
  OpCode.Question.Header.Help            = Help;
  OpCode.Question.QuestionId             = QuestionId;
  OpCode.Question.VarStoreId             = VarStoreId;
  OpCode.Question.VarStoreInfo.VarOffset = VarOffset;
  OpCode.Question.Flags                  = QuestionFlags;
  OpCode.Flags                           = OneOfFlags;

  Position = InternalHiiOpCodeHandlePosition (OpCodeHandle);
  InternalHiiCreateOpCodeExtended (OpCodeHandle, &OpCode, EFI_IFR_ONE_OF_OP, sizeof (OpCode), 0, 1);
  InternalHiiAppendOpCodes (OpCodeHandle, OptionsOpCodeHandle);
  if (DefaultsOpCodeHandle != NULL) {
    InternalHiiAppendOpCodes (OpCodeHandle, DefaultsOpCodeHandle);
  }
  HiiCreateEndOpCode (OpCodeHandle);
  return InternalHiiOpCodeHandleBuffer (OpCodeHandle) + Position;
}

/**
  Create EFI_IFR_ORDERED_LIST_OP opcode.

  If OpCodeHandle is NULL, then ASSERT().
  If any reserved bits are set in QuestionFlags, then ASSERT().
  If any reserved bits are set in OrderedListFlags, then ASSERT().

  @param[in]  OpCodeHandle          Handle to the buffer of opcodes.
  @param[in]  QuestionId            Question ID
  @param[in]  VarStoreId            Storage ID
  @param[in]  VarOffset             Offset in Storage
  @param[in]  Prompt                String ID for Prompt
  @param[in]  Help                  String ID for Help
  @param[in]  QuestionFlags         Flags in Question Header
  @param[in]  OrderedListFlags      Flags for ordered list opcode
  @param[in]  DataType              Type for option value
  @param[in]  MaxContainers         Maximum count for options in this ordered list
  @param[in]  OptionsOpCodeHandle   Handle for a buffer of ONE_OF_OPTION opcodes.
  @param[in]  DefaultsOpCodeHandle  Handle for a buffer of DEFAULT opcodes.  This
                                    is an optional parameter that may be NULL.

  @retval NULL   There is not enough space left in Buffer to add the opcode.
  @retval Other  A pointer to the created opcode.

**/
UINT8 *
EFIAPI
HiiCreateOrderedListOpCode (
  IN VOID             *OpCodeHandle,
  IN EFI_QUESTION_ID  QuestionId,
  IN EFI_VARSTORE_ID  VarStoreId,
  IN UINT16           VarOffset,
  IN EFI_STRING_ID    Prompt,
  IN EFI_STRING_ID    Help,
  IN UINT8            QuestionFlags,
  IN UINT8            OrderedListFlags,
  IN UINT8            DataType,
  IN UINT8            MaxContainers,
  IN VOID             *OptionsOpCodeHandle,
  IN VOID             *DefaultsOpCodeHandle  OPTIONAL
  )
{
  EFI_IFR_ORDERED_LIST  OpCode;
  UINTN                 Position;

  ASSERT (OptionsOpCodeHandle != NULL);
  ASSERT ((QuestionFlags & (~(EFI_IFR_FLAG_READ_ONLY | EFI_IFR_FLAG_CALLBACK | EFI_IFR_FLAG_RESET_REQUIRED | EFI_IFR_FLAG_OPTIONS_ONLY))) == 0);

  ZeroMem (&OpCode, sizeof (OpCode));
  OpCode.Question.Header.Prompt          = Prompt;
  OpCode.Question.Header.Help            = Help;
  OpCode.Question.QuestionId             = QuestionId;
  OpCode.Question.VarStoreId             = VarStoreId;
  OpCode.Question.VarStoreInfo.VarOffset = VarOffset;
  OpCode.Question.Flags                  = QuestionFlags;
  OpCode.MaxContainers                   = MaxContainers;
  OpCode.Flags                           = OrderedListFlags;

  Position = InternalHiiOpCodeHandlePosition (OpCodeHandle);
  InternalHiiCreateOpCodeExtended (OpCodeHandle, &OpCode, EFI_IFR_ORDERED_LIST_OP, sizeof (OpCode), 0, 1);
  InternalHiiAppendOpCodes (OpCodeHandle, OptionsOpCodeHandle);
  if (DefaultsOpCodeHandle != NULL) {
    InternalHiiAppendOpCodes (OpCodeHandle, DefaultsOpCodeHandle);
  }
  HiiCreateEndOpCode (OpCodeHandle);
  return InternalHiiOpCodeHandleBuffer (OpCodeHandle) + Position;
}

/**
  This is the internal worker function to update the data in
  a form specified by FormSetGuid, FormId and Label.

  @param FormSetGuid     The optional Formset GUID.
  @param FormId          The Form ID.
  @param Package         The package header.

  @param TempPacakge     The resultant package.

  @retval EFI_SUCCESS    The function completes successfully.

**/
EFI_STATUS
EFIAPI
InternalHiiUpdateFormPackageData (
  IN  EFI_GUID               *FormSetGuid, OPTIONAL
  IN  EFI_FORM_ID            FormId,
  IN  EFI_HII_PACKAGE_HEADER *Package,
  IN  HII_LIB_OPCODE_BUFFER  *OpCodeBufferStart,
  IN  HII_LIB_OPCODE_BUFFER  *OpCodeBufferEnd,    OPTIONAL
  OUT EFI_HII_PACKAGE_HEADER *TempPackage
  )
{
  UINTN                     AddSize;
  UINT8                     *BufferPos;
  EFI_HII_PACKAGE_HEADER    PackageHeader;
  UINTN                     Offset;
  EFI_IFR_OP_HEADER         *IfrOpHdr;
  EFI_IFR_OP_HEADER         *UpdateIfrOpHdr;
  BOOLEAN                   GetFormSet;
  BOOLEAN                   GetForm;
  BOOLEAN                   Updated;
  EFI_IFR_OP_HEADER         *AddOpCode;
  UINT32                    UpdatePackageLength;

  CopyMem (TempPackage, Package, sizeof (EFI_HII_PACKAGE_HEADER));
  UpdatePackageLength = sizeof (EFI_HII_PACKAGE_HEADER);
  BufferPos           = (UINT8 *) (TempPackage + 1);

  CopyMem (&PackageHeader, Package, sizeof (EFI_HII_PACKAGE_HEADER));
  IfrOpHdr   = (EFI_IFR_OP_HEADER *)((UINT8 *) Package + sizeof (EFI_HII_PACKAGE_HEADER));
  Offset     = sizeof (EFI_HII_PACKAGE_HEADER);
  GetFormSet = (BOOLEAN) ((FormSetGuid == NULL) ? TRUE : FALSE);
  GetForm    = FALSE;
  Updated    = FALSE;

  while (Offset < PackageHeader.Length) {
    CopyMem (BufferPos, IfrOpHdr, IfrOpHdr->Length);
    BufferPos           += IfrOpHdr->Length;
    UpdatePackageLength += IfrOpHdr->Length;
    
    //
    // Find the matched FormSet and Form
    //
    if ((IfrOpHdr->OpCode == EFI_IFR_FORM_SET_OP) && (FormSetGuid != NULL)) {
      if (CompareGuid((GUID *)(VOID *)&((EFI_IFR_FORM_SET *) IfrOpHdr)->Guid, FormSetGuid)) {
        GetFormSet = TRUE;
      } else {
        GetFormSet = FALSE;
      }
    } else if (IfrOpHdr->OpCode == EFI_IFR_FORM_OP) {
      if (CompareMem (&((EFI_IFR_FORM *) IfrOpHdr)->FormId, &FormId, sizeof (EFI_FORM_ID)) == 0) {
        GetForm = TRUE;
      } else {
        GetForm = FALSE;
      }
    }
    
    //
    // The matched Form is found, and Update data in this form
    //
    if (GetFormSet && GetForm && !Updated) {
      UpdateIfrOpHdr = (EFI_IFR_OP_HEADER *) OpCodeBufferStart->Buffer;
      if ((UpdateIfrOpHdr->Length == IfrOpHdr->Length) && \
          (CompareMem (IfrOpHdr, UpdateIfrOpHdr, UpdateIfrOpHdr->Length) == 0)) {
        //
        // Remove the original data when End OpCode buffer exist.
        //
        if (OpCodeBufferEnd != NULL) {
          Offset        += IfrOpHdr->Length;
          IfrOpHdr       = (EFI_IFR_OP_HEADER *) ((UINT8 *) (IfrOpHdr) + IfrOpHdr->Length);
          UpdateIfrOpHdr = (EFI_IFR_OP_HEADER *) OpCodeBufferEnd->Buffer;
          while (Offset < PackageHeader.Length) {
            //
            // Search the matched end opcode
            //
            if ((UpdateIfrOpHdr->Length == IfrOpHdr->Length) && \
                (CompareMem (IfrOpHdr, UpdateIfrOpHdr, UpdateIfrOpHdr->Length) == 0)) {
              break;
            }
            //
            // Go to the next Op-Code
            //
            Offset        += IfrOpHdr->Length;
            IfrOpHdr       = (EFI_IFR_OP_HEADER *) ((UINT8 *) (IfrOpHdr) + IfrOpHdr->Length);
          }
          
          if (Offset >= PackageHeader.Length) {
            //
            // The end opcode is not found.
            //
            return EFI_NOT_FOUND;
          }
        }
        //
        // Insert the updated data
        //
        UpdateIfrOpHdr = (EFI_IFR_OP_HEADER *) OpCodeBufferStart->Buffer;
        AddOpCode      = (EFI_IFR_OP_HEADER *) (OpCodeBufferStart->Buffer + UpdateIfrOpHdr->Length);
        AddSize        = UpdateIfrOpHdr->Length;
        while (AddSize < OpCodeBufferStart->Position) {
          CopyMem (BufferPos, AddOpCode, AddOpCode->Length);
          BufferPos           += AddOpCode->Length;
          UpdatePackageLength += AddOpCode->Length;

          AddOpCode = (EFI_IFR_OP_HEADER *) ((UINT8 *) (AddOpCode) + AddOpCode->Length);
          AddSize += AddOpCode->Length;          
        }

        if (OpCodeBufferEnd != NULL) {
          //
          // Add the end opcode
          //
          CopyMem (BufferPos, IfrOpHdr, IfrOpHdr->Length);
          BufferPos           += IfrOpHdr->Length;
          UpdatePackageLength += IfrOpHdr->Length;
        }
        //
        // Set update flag
        //
        Updated = TRUE;
      }
    }

    //
    // Go to the next Op-Code
    //
    Offset   += IfrOpHdr->Length;
    IfrOpHdr = (EFI_IFR_OP_HEADER *) ((CHAR8 *) (IfrOpHdr) + IfrOpHdr->Length);
  }
  
  if (!Updated) {
    //
    // The updated opcode buffer is not found.
    //
    return EFI_NOT_FOUND;
  }
  //
  // Update the package length.
  //
  PackageHeader.Length = UpdatePackageLength;
  CopyMem (TempPackage, &PackageHeader, sizeof (EFI_HII_PACKAGE_HEADER));

  return EFI_SUCCESS;
}

/**
  This function updates a form that has previously been registered with the HII 
  Database.  This function will perform at most one update operation.
    
  The form to update is specified by Handle, FormSetGuid, and FormId.  Binary 
  comparisons of IFR opcodes are performed from the beginning of the form being 
  updated until an IFR opcode is found that exactly matches the first IFR opcode 
  specifed by StartOpCodeHandle.  The following rules are used to determine if
  an insert, replace, or delete operation is performed.
  
  1) If no matches are found, then NULL is returned.  
  2) If a match is found, and EndOpCodeHandle is NULL, then all of the IFR opcodes
     from StartOpcodeHandle except the first opcode are inserted immediately after 
     the matching IFR opcode in the form beng updated.
  3) If a match is found, and EndOpCodeHandle is not NULL, then a search is made 
     from the matching IFR opcode until an IFR opcode exatly matches the first 
     IFR opcode specified by EndOpCodeHandle.  If no match is found for the first
     IFR opcode specified by EndOpCodeHandle, then NULL is returned.  If a match
     is found, then all of the IFR opcodes between the start match and the end 
     match are deleted from the form being updated and all of the IFR opcodes
     from StartOpcodeHandle except the first opcode are inserted immediately after 
     the matching start IFR opcode.  If StartOpCcodeHandle only contains one
     IFR instruction, then the result of ths operation will delete all of the IFR
     opcodes between the start end matches.

  If HiiHandle is NULL, then ASSERT().
  If StartOpCodeHandle is NULL, then ASSERT().

  @param[in]  HiiHandle          The HII Handle of the form to update.
  @param[in]  FormSetGuid        The Formset GUID of the form to update.  This
                                 is an optional parameter that may be NULL.
                                 If it is NULL, all FormSet will be updated.
  @param[in]  FormId             The ID of the form to update.
  @param[in]  StartOpCodeHandle  An OpCode Handle that contains the set of IFR 
                                 opcodes to be inserted or replaced in the form.
                                 The first IFR instruction in StartOpCodeHandle 
                                 is used to find matching IFR opcode in the 
                                 form. 
  @param[in]  EndOpCodeHandle    An OpCcode Handle that contains the IFR opcode
                                 that marks the end of a replace operation in
                                 the form.  This is an optional parameter that
                                 may be NULL.  If it is NULL, then an the IFR
                                 opcodes specified by StartOpCodeHandle are 
                                 inserted into the form.
  
  @retval EFI_OUT_OF_RESOURCES   No enough memory resource is allocated.
  @retval EFI_NOT_FOUND          The following cases will return EFI_NOT_FOUND.
                                 1) The form specified by HiiHandle, FormSetGuid, 
                                 and FormId could not be found in the HII Database.
                                 2) No IFR opcodes in the target form match the first
                                 IFR opcode in StartOpCodeHandle.
                                 3) EndOpCOde is not NULL, and no IFR opcodes in the 
                                 target form following a matching start opcode match 
                                 the first IFR opcode in EndOpCodeHandle.
  @retval EFI_SUCCESS            The matched form is updated by StartOpcode.

**/
EFI_STATUS
EFIAPI
HiiUpdateForm (
  IN EFI_HII_HANDLE  HiiHandle,           
  IN EFI_GUID        *FormSetGuid,        OPTIONAL
  IN EFI_FORM_ID     FormId,
  IN VOID            *StartOpcodeHandle,
  IN VOID            *EndOpcodeHandle     OPTIONAL
  )
{
  EFI_STATUS                   Status;
  EFI_HII_PACKAGE_LIST_HEADER  *HiiPackageList;
  UINT32                       PackageListLength;  
  UINT32                       Offset;
  EFI_HII_PACKAGE_LIST_HEADER  *UpdatePackageList;
  UINTN                        BufferSize;
  UINT8                        *UpdateBufferPos;
  EFI_HII_PACKAGE_HEADER       *Package;
  EFI_HII_PACKAGE_HEADER       *TempPacakge;
  EFI_HII_PACKAGE_HEADER       PackageHeader;
  BOOLEAN                      Updated;
  HII_LIB_OPCODE_BUFFER        *OpCodeBufferStart;
  HII_LIB_OPCODE_BUFFER        *OpCodeBufferEnd;
  
  //
  // Input update data can't be NULL.
  //
  ASSERT (HiiHandle != NULL);
  ASSERT (StartOpcodeHandle != NULL);
  UpdatePackageList = NULL;
  TempPacakge       = NULL;
  HiiPackageList    = NULL;
  
  //
  // Restrive buffer data from Opcode Handle
  //
  OpCodeBufferStart = (HII_LIB_OPCODE_BUFFER *) StartOpcodeHandle;
  OpCodeBufferEnd   = (HII_LIB_OPCODE_BUFFER *) EndOpcodeHandle;
  
  //
  // Get the orginal package list
  //
  BufferSize = 0;
  HiiPackageList   = NULL;
  Status = gHiiDatabase->ExportPackageLists (gHiiDatabase, HiiHandle, &BufferSize, HiiPackageList);
  //
  // The return status should always be EFI_BUFFER_TOO_SMALL as input buffer's size is 0.
  //
  if (Status != EFI_BUFFER_TOO_SMALL) {
    return Status;
  }

  HiiPackageList = AllocatePool (BufferSize);
  if (HiiPackageList == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto Finish;
  }

  Status = gHiiDatabase->ExportPackageLists (gHiiDatabase, HiiHandle, &BufferSize, HiiPackageList);
  if (EFI_ERROR (Status)) {
    goto Finish;
  }

  //
  // Calculate and allocate space for retrieval of IFR data
  //
  BufferSize += OpCodeBufferStart->Position;
  UpdatePackageList = AllocateZeroPool (BufferSize);
  if (UpdatePackageList == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto Finish;
  }
  
  //
  // Allocate temp buffer to store the temp updated package buffer
  //
  TempPacakge = AllocateZeroPool (BufferSize);
  if (TempPacakge == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto Finish;
  }

  UpdateBufferPos = (UINT8 *) UpdatePackageList;

  //
  // Copy the package list header
  //
  CopyMem (UpdateBufferPos, HiiPackageList, sizeof (EFI_HII_PACKAGE_LIST_HEADER));
  UpdateBufferPos += sizeof (EFI_HII_PACKAGE_LIST_HEADER);
  
  //
  // Go through each package to find the matched pacakge and update one by one
  //
  Updated = FALSE;
  Offset  = sizeof (EFI_HII_PACKAGE_LIST_HEADER);
  PackageListLength = ReadUnaligned32 (&HiiPackageList->PackageLength);
  while (Offset < PackageListLength) {
    Package = (EFI_HII_PACKAGE_HEADER *) (((UINT8 *) HiiPackageList) + Offset);
    CopyMem (&PackageHeader, Package, sizeof (EFI_HII_PACKAGE_HEADER));
    Offset += Package->Length;

    if (Package->Type == EFI_HII_PACKAGE_FORMS) {
      //
      // Check this package is the matched package.
      //
      Status = InternalHiiUpdateFormPackageData (FormSetGuid, FormId, Package, OpCodeBufferStart, OpCodeBufferEnd, TempPacakge);
      //
      // The matched package is found. Its pacakge buffer will be updated by the input new data.
      //
      if (!EFI_ERROR(Status)) {
        //
        // Set Update Flag
        //        
        Updated = TRUE;
        //
        // Add updated package buffer
        //
        Package = TempPacakge;
      }
    }

    //
    // Add pacakge buffer
    //
    CopyMem (&PackageHeader, Package, sizeof (EFI_HII_PACKAGE_HEADER));
    CopyMem (UpdateBufferPos, Package, PackageHeader.Length);
    UpdateBufferPos += PackageHeader.Length;
  }
  
  if (Updated) {
    //
    // Update package list length
    //
    BufferSize = UpdateBufferPos - (UINT8 *) UpdatePackageList;
    WriteUnaligned32 (&UpdatePackageList->PackageLength, (UINT32) BufferSize);
    
    //
    // Update Pacakge to show form
    //
    Status = gHiiDatabase->UpdatePackageList (gHiiDatabase, HiiHandle, UpdatePackageList);
  } else {
    //
    // Not matched form is found and updated.
    //
    Status = EFI_NOT_FOUND;
  }

Finish:
  if (HiiPackageList != NULL) {
    FreePool (HiiPackageList);
  }
  
  if (UpdatePackageList != NULL) {
    FreePool (UpdatePackageList);
  }
  
  if (TempPacakge != NULL) {
    FreePool (TempPacakge);
  }

  return Status; 
}

/**
  Configure the buffer accrording to ConfigBody strings in the format of
  <Length:4 bytes>, <Offset: 2 bytes>, <Width:2 bytes>, <Data:n bytes>.
  This ConfigBody strings is generated by UEFI VfrCompiler for the default
  values in a Form Set. The name of the ConfigBody strings is VfrMyIfrNVDataDefault0000
  constructed following this rule: 
   "Vfr" + varstore.name + "Default" + defaultstore.attributes.
  Check the generated C file in Output for details.

  @param  Buffer                 The start address of buffer.
  @param  BufferSize             The size of buffer.
  @param  Number                 The number of the strings.
  @param  ...                    Variable argument list for default value in <AltResp> format 
                                 generated by the tool.

  @retval EFI_BUFFER_TOO_SMALL   the BufferSize is too small to operate.
  @retval EFI_INVALID_PARAMETER  Buffer is NULL or BufferSize is 0.
  @retval EFI_SUCCESS            Operation successful.

**/
EFI_STATUS
EFIAPI
HiiIfrLibExtractDefault(
  IN VOID                         *Buffer,
  IN UINTN                        *BufferSize,
  UINTN                           Number,
  ...
  )
{
  VA_LIST                         Args;
  UINTN                           Index;
  UINT32                          TotalLen;
  UINT8                           *BufCfgArray;
  UINT8                           *BufferPos;
  UINT16                          Offset;
  UINT16                          Width;
  UINT8                           *Value;

  if ((Buffer == NULL) || (BufferSize == NULL)) {
    return EFI_INVALID_PARAMETER;
  }

  Offset = 0;
  Width  = 0;
  Value  = NULL;

  VA_START (Args, Number);
  for (Index = 0; Index < Number; Index++) {
    BufCfgArray = (UINT8 *) VA_ARG (Args, VOID *);
    TotalLen = ReadUnaligned32 ((UINT32 *)BufCfgArray);
    BufferPos = BufCfgArray + sizeof (UINT32);

    while ((UINT32)(BufferPos - BufCfgArray) < TotalLen) {
      Offset = ReadUnaligned16 ((UINT16 *)BufferPos);
      BufferPos += sizeof (UINT16);
      Width = ReadUnaligned16 ((UINT16 *)BufferPos);
      BufferPos += sizeof (UINT16);
      Value = BufferPos;
      BufferPos += Width;

      if ((UINTN)(Offset + Width) > *BufferSize) {
        return EFI_BUFFER_TOO_SMALL;
      }

      CopyMem ((UINT8 *)Buffer + Offset, Value, Width);
    }
  }
  VA_END (Args);

  *BufferSize = (UINTN)Offset;

  return EFI_SUCCESS;
}