/** @file
Parser for IFR binary encoding.

Copyright (c) 2007 - 2019, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include "Setup.h"

UINT16           mStatementIndex;
UINT16           mExpressionOpCodeIndex;
EFI_QUESTION_ID  mUsedQuestionId;
extern LIST_ENTRY      gBrowserStorageList;
/**
  Initialize Statement header members.

  @param  OpCodeData             Pointer of the raw OpCode data.
  @param  FormSet                Pointer of the current FormSet.
  @param  Form                   Pointer of the current Form.

  @return The Statement.

**/
FORM_BROWSER_STATEMENT *
CreateStatement (
  IN UINT8                        *OpCodeData,
  IN OUT FORM_BROWSER_FORMSET     *FormSet,
  IN OUT FORM_BROWSER_FORM        *Form
  )
{
  FORM_BROWSER_STATEMENT    *Statement;
  EFI_IFR_STATEMENT_HEADER  *StatementHdr;
  INTN                      ConditionalExprCount;

  if (Form == NULL) {
    //
    // Only guid op may out side the form level.
    //
    ASSERT (((EFI_IFR_OP_HEADER *) OpCodeData)->OpCode == EFI_IFR_GUID_OP);
  }

  Statement = &FormSet->StatementBuffer[mStatementIndex];
  mStatementIndex++;

  InitializeListHead (&Statement->DefaultListHead);
  InitializeListHead (&Statement->OptionListHead);
  InitializeListHead (&Statement->InconsistentListHead);
  InitializeListHead (&Statement->NoSubmitListHead);
  InitializeListHead (&Statement->WarningListHead);

  Statement->Signature = FORM_BROWSER_STATEMENT_SIGNATURE;

  Statement->Operand = ((EFI_IFR_OP_HEADER *) OpCodeData)->OpCode;
  Statement->OpCode  = (EFI_IFR_OP_HEADER *) OpCodeData;
  Statement->QuestionReferToBitField = FALSE;

  StatementHdr = (EFI_IFR_STATEMENT_HEADER *) (OpCodeData + sizeof (EFI_IFR_OP_HEADER));
  CopyMem (&Statement->Prompt, &StatementHdr->Prompt, sizeof (EFI_STRING_ID));
  CopyMem (&Statement->Help, &StatementHdr->Help, sizeof (EFI_STRING_ID));

  ConditionalExprCount = GetConditionalExpressionCount(ExpressStatement);
  if (ConditionalExprCount > 0) {
    //
    // Form is inside of suppressif
    //

    Statement->Expression = (FORM_EXPRESSION_LIST *) AllocatePool(
                                             (UINTN) (sizeof(FORM_EXPRESSION_LIST) + ((ConditionalExprCount -1) * sizeof(FORM_EXPRESSION *))));
    ASSERT (Statement->Expression != NULL);
    Statement->Expression->Count     = (UINTN) ConditionalExprCount;
    Statement->Expression->Signature = FORM_EXPRESSION_LIST_SIGNATURE;
    CopyMem (Statement->Expression->Expression, GetConditionalExpressionList(ExpressStatement), (UINTN) (sizeof (FORM_EXPRESSION *) * ConditionalExprCount));
  }

  //
  // Insert this Statement into current Form
  //
  if (Form == NULL) {
    InsertTailList (&FormSet->StatementListOSF, &Statement->Link);
  } else {
    InsertTailList (&Form->StatementListHead, &Statement->Link);
  }
  return Statement;
}

/**
  Initialize Question's members.

  @param  OpCodeData             Pointer of the raw OpCode data.
  @param  FormSet                Pointer of the current FormSet.
  @param  Form                   Pointer of the current Form.

  @return The Question.

**/
FORM_BROWSER_STATEMENT *
CreateQuestion (
  IN UINT8                        *OpCodeData,
  IN OUT FORM_BROWSER_FORMSET     *FormSet,
  IN OUT FORM_BROWSER_FORM        *Form
  )
{
  FORM_BROWSER_STATEMENT   *Statement;
  EFI_IFR_QUESTION_HEADER  *QuestionHdr;
  LIST_ENTRY               *Link;
  FORMSET_STORAGE          *Storage;
  NAME_VALUE_NODE          *NameValueNode;
  BOOLEAN                  Find;

  Statement = CreateStatement (OpCodeData, FormSet, Form);
  if (Statement == NULL) {
    return NULL;
  }

  QuestionHdr = (EFI_IFR_QUESTION_HEADER *) (OpCodeData + sizeof (EFI_IFR_OP_HEADER));
  CopyMem (&Statement->QuestionId, &QuestionHdr->QuestionId, sizeof (EFI_QUESTION_ID));
  CopyMem (&Statement->VarStoreId, &QuestionHdr->VarStoreId, sizeof (EFI_VARSTORE_ID));
  CopyMem (&Statement->VarStoreInfo.VarOffset, &QuestionHdr->VarStoreInfo.VarOffset, sizeof (UINT16));

  Statement->QuestionFlags = QuestionHdr->Flags;

  if (Statement->VarStoreId == 0) {
    //
    // VarStoreId of zero indicates no variable storage
    //
    return Statement;
  }

  //
  // Find Storage for this Question
  //
  Link = GetFirstNode (&FormSet->StorageListHead);
  while (!IsNull (&FormSet->StorageListHead, Link)) {
    Storage = FORMSET_STORAGE_FROM_LINK (Link);

    if (Storage->VarStoreId == Statement->VarStoreId) {
      Statement->Storage = Storage->BrowserStorage;
      break;
    }

    Link = GetNextNode (&FormSet->StorageListHead, Link);
  }
  ASSERT (Statement->Storage != NULL);

  //
  // Initialilze varname for Name/Value or EFI Variable
  //
  if ((Statement->Storage->Type == EFI_HII_VARSTORE_NAME_VALUE) ||
      (Statement->Storage->Type == EFI_HII_VARSTORE_EFI_VARIABLE)) {
    Statement->VariableName = GetToken (Statement->VarStoreInfo.VarName, FormSet->HiiHandle);
    ASSERT (Statement->VariableName != NULL);

    if (Statement->Storage->Type == EFI_HII_VARSTORE_NAME_VALUE) {
      //
      // Check whether old string node already exist.
      //
      Find = FALSE;
      if (!IsListEmpty(&Statement->Storage->NameValueListHead)) {
        Link = GetFirstNode (&Statement->Storage->NameValueListHead);
        while (!IsNull (&Statement->Storage->NameValueListHead, Link)) {
          NameValueNode = NAME_VALUE_NODE_FROM_LINK (Link);

          if (StrCmp (Statement->VariableName, NameValueNode->Name) == 0) {
            Find = TRUE;
            break;
          }

          Link = GetNextNode (&Statement->Storage->NameValueListHead, Link);
        }
      }

      if (!Find) {
        //
        // Insert to Name/Value varstore list
        //
        NameValueNode = AllocateZeroPool (sizeof (NAME_VALUE_NODE));
        ASSERT (NameValueNode != NULL);
        NameValueNode->Signature = NAME_VALUE_NODE_SIGNATURE;
        NameValueNode->Name = AllocateCopyPool(StrSize (Statement->VariableName), Statement->VariableName);
        ASSERT (NameValueNode->Name != NULL);
        NameValueNode->Value = AllocateZeroPool (0x10);
        ASSERT (NameValueNode->Value != NULL);
        NameValueNode->EditValue = AllocateZeroPool (0x10);
        ASSERT (NameValueNode->EditValue != NULL);

        InsertTailList (&Statement->Storage->NameValueListHead, &NameValueNode->Link);
      }
    }
  }

  return Statement;
}


/**
  Allocate a FORM_EXPRESSION node.

  @param  Form                   The Form associated with this Expression
  @param  OpCode                 The binary opcode data.

  @return Pointer to a FORM_EXPRESSION data structure.

**/
FORM_EXPRESSION *
CreateExpression (
  IN OUT FORM_BROWSER_FORM        *Form,
  IN     UINT8                    *OpCode
  )
{
  FORM_EXPRESSION  *Expression;

  Expression = AllocateZeroPool (sizeof (FORM_EXPRESSION));
  ASSERT (Expression != NULL);
  Expression->Signature = FORM_EXPRESSION_SIGNATURE;
  InitializeListHead (&Expression->OpCodeListHead);
  Expression->OpCode = (EFI_IFR_OP_HEADER *) OpCode;

  return Expression;
}

/**
  Create ConfigHdr string for a storage.

  @param  FormSet                Pointer of the current FormSet
  @param  Storage                Pointer of the storage

  @retval EFI_SUCCESS            Initialize ConfigHdr success

**/
EFI_STATUS
InitializeConfigHdr (
  IN FORM_BROWSER_FORMSET  *FormSet,
  IN OUT FORMSET_STORAGE   *Storage
  )
{
  CHAR16      *Name;

  if (Storage->BrowserStorage->Type == EFI_HII_VARSTORE_BUFFER ||
      Storage->BrowserStorage->Type == EFI_HII_VARSTORE_EFI_VARIABLE_BUFFER) {
    Name = Storage->BrowserStorage->Name;
  } else {
    Name = NULL;
  }

  Storage->ConfigHdr = HiiConstructConfigHdr (
                         &Storage->BrowserStorage->Guid,
                         Name,
                         FormSet->DriverHandle
                         );

  if (Storage->ConfigHdr == NULL) {
    return EFI_NOT_FOUND;
  }

  return EFI_SUCCESS;
}

/**
  Find the global storage link base on the input storate type, name and guid.

  For EFI_HII_VARSTORE_EFI_VARIABLE and EFI_HII_VARSTORE_EFI_VARIABLE_BUFFER,
  same guid + name = same storage

  For EFI_HII_VARSTORE_NAME_VALUE:
  same guid + HiiHandle = same storage

  For EFI_HII_VARSTORE_BUFFER:
  same guid + name + HiiHandle = same storage

  @param  StorageType                Storage type.
  @param  StorageGuid                Storage guid.
  @param  StorageName                Storage Name.
  @param  HiiHandle                  HiiHandle for this varstore.

  @return Pointer to a GLOBAL_STORAGE data structure.

**/
BROWSER_STORAGE *
FindStorageInList (
  IN UINT8                 StorageType,
  IN EFI_GUID              *StorageGuid,
  IN CHAR16                *StorageName,
  IN EFI_HII_HANDLE        HiiHandle
  )
{
  LIST_ENTRY       *Link;
  BROWSER_STORAGE  *BrowserStorage;

  Link  = GetFirstNode (&gBrowserStorageList);
  while (!IsNull (&gBrowserStorageList, Link)) {
    BrowserStorage = BROWSER_STORAGE_FROM_LINK (Link);
    Link = GetNextNode (&gBrowserStorageList, Link);

    if ((BrowserStorage->Type == StorageType) && CompareGuid (&BrowserStorage->Guid, StorageGuid)) {
      if (StorageType == EFI_HII_VARSTORE_NAME_VALUE) {
        if (BrowserStorage->HiiHandle == HiiHandle) {
          return BrowserStorage;
        }

        continue;
      }

      ASSERT (StorageName != NULL);
      if (StrCmp (BrowserStorage->Name, StorageName) == 0) {
        if (StorageType == EFI_HII_VARSTORE_EFI_VARIABLE || StorageType == EFI_HII_VARSTORE_EFI_VARIABLE_BUFFER) {
          return BrowserStorage;
        } else if (StorageType == EFI_HII_VARSTORE_BUFFER && BrowserStorage->HiiHandle == HiiHandle) {
          return BrowserStorage;
        }
      }
    }
  }

  return NULL;
}

/**
  Intialize the Global Storage.

  @param  BrowserStorage              Pointer to the global storage.
  @param  StorageType                Storage type.
  @param  OpCodeData                 Binary data for this opcode.

**/
VOID
IntializeBrowserStorage (
  IN BROWSER_STORAGE       *BrowserStorage,
  IN UINT8                 StorageType,
  IN UINT8                 *OpCodeData
  )
{
  switch (StorageType) {
    case EFI_HII_VARSTORE_BUFFER:
      CopyMem (&BrowserStorage->Guid, &((EFI_IFR_VARSTORE *) OpCodeData)->Guid, sizeof (EFI_GUID));
      CopyMem (&BrowserStorage->Size, &((EFI_IFR_VARSTORE *) OpCodeData)->Size, sizeof (UINT16));

      BrowserStorage->Buffer     = AllocateZeroPool (BrowserStorage->Size);
      BrowserStorage->EditBuffer = AllocateZeroPool (BrowserStorage->Size);
      break;

    case EFI_HII_VARSTORE_EFI_VARIABLE:
    case EFI_HII_VARSTORE_EFI_VARIABLE_BUFFER:
      CopyMem (&BrowserStorage->Guid,       &((EFI_IFR_VARSTORE_EFI *) OpCodeData)->Guid,       sizeof (EFI_GUID));
      CopyMem (&BrowserStorage->Attributes, &((EFI_IFR_VARSTORE_EFI *) OpCodeData)->Attributes, sizeof (UINT32));
      CopyMem (&BrowserStorage->Size,       &((EFI_IFR_VARSTORE_EFI *) OpCodeData)->Size,       sizeof (UINT16));

      if (StorageType ==  EFI_HII_VARSTORE_EFI_VARIABLE_BUFFER) {
        BrowserStorage->Buffer     = AllocateZeroPool (BrowserStorage->Size);
        BrowserStorage->EditBuffer = AllocateZeroPool (BrowserStorage->Size);
      }
      break;

    case EFI_HII_VARSTORE_NAME_VALUE:
      CopyMem (&BrowserStorage->Guid, &((EFI_IFR_VARSTORE_NAME_VALUE *) OpCodeData)->Guid, sizeof (EFI_GUID));

      InitializeListHead (&BrowserStorage->NameValueListHead);
      break;

    default:
      break;
  }
}


/**
  Allocate a FORMSET_STORAGE data structure and insert to FormSet Storage List.

  @param  FormSet                    Pointer of the current FormSet
  @param  StorageType                Storage type.
  @param  OpCodeData                 Binary data for this opcode.

  @return Pointer to a FORMSET_STORAGE data structure.

**/
FORMSET_STORAGE *
CreateStorage (
  IN FORM_BROWSER_FORMSET  *FormSet,
  IN UINT8                 StorageType,
  IN UINT8                 *OpCodeData
  )
{
  FORMSET_STORAGE         *Storage;
  CHAR16                  *UnicodeString;
  UINT16                  Index;
  BROWSER_STORAGE         *BrowserStorage;
  EFI_GUID                *StorageGuid;
  CHAR8                   *StorageName;

  UnicodeString = NULL;
  StorageName   = NULL;
  switch (StorageType) {
    case EFI_HII_VARSTORE_BUFFER:
      StorageGuid = (EFI_GUID *) (CHAR8*) &((EFI_IFR_VARSTORE *) OpCodeData)->Guid;
      StorageName = (CHAR8 *) ((EFI_IFR_VARSTORE *) OpCodeData)->Name;
      break;

    case EFI_HII_VARSTORE_EFI_VARIABLE:
    case EFI_HII_VARSTORE_EFI_VARIABLE_BUFFER:
      StorageGuid = (EFI_GUID *) (CHAR8*) &((EFI_IFR_VARSTORE_EFI *) OpCodeData)->Guid;
      StorageName = (CHAR8 *) ((EFI_IFR_VARSTORE_EFI *) OpCodeData)->Name;
      break;

    default:
      ASSERT (StorageType == EFI_HII_VARSTORE_NAME_VALUE);
      StorageGuid = &((EFI_IFR_VARSTORE_NAME_VALUE *) OpCodeData)->Guid;
      break;
  }

  if (StorageType != EFI_HII_VARSTORE_NAME_VALUE) {
    ASSERT (StorageName != NULL);

    UnicodeString = AllocateZeroPool (AsciiStrSize (StorageName) * 2);
    ASSERT (UnicodeString != NULL);
    for (Index = 0; StorageName[Index] != 0; Index++) {
      UnicodeString[Index] = (CHAR16) StorageName[Index];
    }
  }

  Storage = AllocateZeroPool (sizeof (FORMSET_STORAGE));
  ASSERT (Storage != NULL);
  Storage->Signature = FORMSET_STORAGE_SIGNATURE;
  InsertTailList (&FormSet->StorageListHead, &Storage->Link);

  BrowserStorage = FindStorageInList(StorageType, StorageGuid, UnicodeString, FormSet->HiiHandle);
  if (BrowserStorage == NULL) {
    BrowserStorage = AllocateZeroPool (sizeof (BROWSER_STORAGE));
    ASSERT (BrowserStorage != NULL);

    BrowserStorage->Signature = BROWSER_STORAGE_SIGNATURE;
    InsertTailList (&gBrowserStorageList, &BrowserStorage->Link);

    IntializeBrowserStorage (BrowserStorage, StorageType, OpCodeData);
    BrowserStorage->Type = StorageType;
    if (StorageType != EFI_HII_VARSTORE_NAME_VALUE) {
      BrowserStorage->Name = UnicodeString;
    }

    BrowserStorage->HiiHandle = FormSet->HiiHandle;

    BrowserStorage->Initialized = FALSE;
  }

  Storage->BrowserStorage = BrowserStorage;
  InitializeConfigHdr (FormSet, Storage);
  Storage->ConfigRequest = AllocateCopyPool(StrSize (Storage->ConfigHdr), Storage->ConfigHdr);
  Storage->SpareStrLen = 0;

  return Storage;
}

/**
  Get Formset_storage base on the input varstoreid info.

  @param  FormSet                Pointer of the current FormSet.
  @param  VarStoreId             Varstore ID info.

  @return Pointer to a FORMSET_STORAGE data structure.

**/
FORMSET_STORAGE *
GetFstStgFromVarId (
  IN FORM_BROWSER_FORMSET  *FormSet,
  IN EFI_VARSTORE_ID       VarStoreId
  )
{
  FORMSET_STORAGE  *FormsetStorage;
  LIST_ENTRY       *Link;
  BOOLEAN          Found;

  Found = FALSE;
  FormsetStorage = NULL;
  //
  // Find Formset Storage for this Question
  //
  Link = GetFirstNode (&FormSet->StorageListHead);
  while (!IsNull (&FormSet->StorageListHead, Link)) {
    FormsetStorage = FORMSET_STORAGE_FROM_LINK (Link);

    if (FormsetStorage->VarStoreId == VarStoreId) {
      Found = TRUE;
      break;
    }

    Link = GetNextNode (&FormSet->StorageListHead, Link);
  }

  return Found ? FormsetStorage : NULL;
}

/**
  Get Formset_storage base on the input browser storage.

  More than one formsets may share the same browser storage,
  this function just get the first formset storage which
  share the browser storage.

  @param  Storage              browser storage info.

  @return Pointer to a FORMSET_STORAGE data structure.


**/
FORMSET_STORAGE *
GetFstStgFromBrsStg (
  IN BROWSER_STORAGE       *Storage
  )
{
  FORMSET_STORAGE      *FormsetStorage;
  LIST_ENTRY           *Link;
  LIST_ENTRY           *FormsetLink;
  FORM_BROWSER_FORMSET *FormSet;
  BOOLEAN              Found;

  Found = FALSE;
  FormsetStorage = NULL;

  FormsetLink = GetFirstNode (&gBrowserFormSetList);
  while (!IsNull (&gBrowserFormSetList, FormsetLink)) {
    FormSet = FORM_BROWSER_FORMSET_FROM_LINK (FormsetLink);
    FormsetLink = GetNextNode (&gBrowserFormSetList, FormsetLink);

    Link = GetFirstNode (&FormSet->StorageListHead);
    while (!IsNull (&FormSet->StorageListHead, Link)) {
      FormsetStorage = FORMSET_STORAGE_FROM_LINK (Link);
      Link = GetNextNode (&FormSet->StorageListHead, Link);

      if (FormsetStorage->BrowserStorage == Storage) {
        Found = TRUE;
        break;
      }
    }

    if (Found) {
      break;
    }
  }

  return Found ? FormsetStorage : NULL;
}

/**
  Initialize Request Element of a Question. <RequestElement> ::= '&'<BlockName> | '&'<Label>

  @param  FormSet                Pointer of the current FormSet.
  @param  Question               The Question to be initialized.
  @param  Form                   Pointer of the current form.

  @retval EFI_SUCCESS            Function success.
  @retval EFI_INVALID_PARAMETER  No storage associated with the Question.

**/
EFI_STATUS
InitializeRequestElement (
  IN OUT FORM_BROWSER_FORMSET     *FormSet,
  IN OUT FORM_BROWSER_STATEMENT   *Question,
  IN OUT FORM_BROWSER_FORM        *Form
  )
{
  BROWSER_STORAGE  *Storage;
  FORMSET_STORAGE  *FormsetStorage;
  UINTN            StrLen;
  UINTN            StringSize;
  CHAR16           *NewStr;
  CHAR16           RequestElement[30];
  LIST_ENTRY       *Link;
  BOOLEAN          Find;
  FORM_BROWSER_CONFIG_REQUEST  *ConfigInfo;
  UINTN            MaxLen;

  Storage = Question->Storage;
  if (Storage == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  if (Storage->Type == EFI_HII_VARSTORE_EFI_VARIABLE) {
    //
    // <ConfigRequest> is unnecessary for EFI variable storage,
    // GetVariable()/SetVariable() will be used to retrieve/save values
    //
    return EFI_SUCCESS;
  }

  //
  // Prepare <RequestElement>
  //
  if (Storage->Type == EFI_HII_VARSTORE_BUFFER ||
      Storage->Type == EFI_HII_VARSTORE_EFI_VARIABLE_BUFFER) {
    StrLen = UnicodeSPrint (
               RequestElement,
               30 * sizeof (CHAR16),
               L"&OFFSET=%04x&WIDTH=%04x",
               Question->VarStoreInfo.VarOffset,
               Question->StorageWidth
               );
    HiiToLower(RequestElement);
    Question->BlockName = AllocateCopyPool((StrLen + 1) * sizeof (CHAR16), RequestElement);
  } else {
    StrLen = UnicodeSPrint (RequestElement, 30 * sizeof (CHAR16), L"&%s", Question->VariableName);
  }

  if ((Question->Operand == EFI_IFR_PASSWORD_OP) && ((Question->QuestionFlags & EFI_IFR_FLAG_CALLBACK) == EFI_IFR_FLAG_CALLBACK)) {
    //
    // Password with CALLBACK flag is stored in encoded format,
    // so don't need to append it to <ConfigRequest>
    //
    return EFI_SUCCESS;
  }

  //
  // Find Formset Storage for this Question
  //
  FormsetStorage = GetFstStgFromVarId(FormSet, Question->VarStoreId);
  ASSERT (FormsetStorage != NULL);
  StringSize = (FormsetStorage->ConfigRequest != NULL) ? StrSize (FormsetStorage->ConfigRequest) : sizeof (CHAR16);
  MaxLen = StringSize / sizeof (CHAR16) + FormsetStorage->SpareStrLen;

  //
  // Append <RequestElement> to <ConfigRequest>
  //
  if (StrLen > FormsetStorage->SpareStrLen) {
    //
    // Old String buffer is not sufficient for RequestElement, allocate a new one
    //
    MaxLen = StringSize / sizeof (CHAR16) + CONFIG_REQUEST_STRING_INCREMENTAL;
    NewStr = AllocateZeroPool (MaxLen * sizeof (CHAR16));
    ASSERT (NewStr != NULL);
    if (FormsetStorage->ConfigRequest != NULL) {
      CopyMem (NewStr, FormsetStorage->ConfigRequest, StringSize);
      FreePool(FormsetStorage->ConfigRequest);
    }
    FormsetStorage->ConfigRequest = NewStr;
    FormsetStorage->SpareStrLen   = CONFIG_REQUEST_STRING_INCREMENTAL;
  }

  StrCatS (FormsetStorage->ConfigRequest, MaxLen, RequestElement);
  FormsetStorage->ElementCount++;
  FormsetStorage->SpareStrLen -= StrLen;

  //
  // Update the Config Request info saved in the form.
  //
  ConfigInfo = NULL;
  Find       = FALSE;
  Link = GetFirstNode (&Form->ConfigRequestHead);
  while (!IsNull (&Form->ConfigRequestHead, Link)) {
    ConfigInfo = FORM_BROWSER_CONFIG_REQUEST_FROM_LINK (Link);

    if (ConfigInfo != NULL && ConfigInfo->Storage == FormsetStorage->BrowserStorage) {
      Find = TRUE;
      break;
    }

    Link = GetNextNode (&Form->ConfigRequestHead, Link);
  }

  if (!Find) {
    ConfigInfo = AllocateZeroPool(sizeof (FORM_BROWSER_CONFIG_REQUEST));
    ASSERT (ConfigInfo != NULL);
    ConfigInfo->Signature     = FORM_BROWSER_CONFIG_REQUEST_SIGNATURE;
    ConfigInfo->ConfigRequest = AllocateCopyPool(StrSize (FormsetStorage->ConfigHdr), FormsetStorage->ConfigHdr);
    ASSERT (ConfigInfo->ConfigRequest != NULL);
    ConfigInfo->SpareStrLen   = 0;
    ConfigInfo->Storage       = FormsetStorage->BrowserStorage;
    InsertTailList(&Form->ConfigRequestHead, &ConfigInfo->Link);
  }
  StringSize = (ConfigInfo->ConfigRequest != NULL) ? StrSize (ConfigInfo->ConfigRequest) : sizeof (CHAR16);
  MaxLen = StringSize / sizeof (CHAR16) + ConfigInfo->SpareStrLen;

  //
  // Append <RequestElement> to <ConfigRequest>
  //
  if (StrLen > ConfigInfo->SpareStrLen) {
    //
    // Old String buffer is not sufficient for RequestElement, allocate a new one
    //
    MaxLen = StringSize / sizeof (CHAR16) + CONFIG_REQUEST_STRING_INCREMENTAL;
    NewStr = AllocateZeroPool (MaxLen * sizeof (CHAR16));
    ASSERT (NewStr != NULL);
    if (ConfigInfo->ConfigRequest != NULL) {
      CopyMem (NewStr, ConfigInfo->ConfigRequest, StringSize);
      FreePool(ConfigInfo->ConfigRequest);
    }
    ConfigInfo->ConfigRequest = NewStr;
    ConfigInfo->SpareStrLen   = CONFIG_REQUEST_STRING_INCREMENTAL;
  }

  StrCatS (ConfigInfo->ConfigRequest, MaxLen, RequestElement);
  ConfigInfo->ElementCount++;
  ConfigInfo->SpareStrLen -= StrLen;
  return EFI_SUCCESS;
}


/**
  Free resources of a Expression.

  @param  FormSet                Pointer of the Expression

**/
VOID
DestroyExpression (
  IN FORM_EXPRESSION   *Expression
  )
{
  LIST_ENTRY         *Link;
  EXPRESSION_OPCODE  *OpCode;
  LIST_ENTRY         *SubExpressionLink;
  FORM_EXPRESSION    *SubExpression;

  while (!IsListEmpty (&Expression->OpCodeListHead)) {
    Link = GetFirstNode (&Expression->OpCodeListHead);
    OpCode = EXPRESSION_OPCODE_FROM_LINK (Link);
    RemoveEntryList (&OpCode->Link);

    if (OpCode->ValueList != NULL) {
      FreePool(OpCode->ValueList);
    }

    if (OpCode->ValueName != NULL) {
      FreePool(OpCode->ValueName);
    }

    if (OpCode->MapExpressionList.ForwardLink != NULL) {
      while (!IsListEmpty (&OpCode->MapExpressionList)) {
        SubExpressionLink = GetFirstNode(&OpCode->MapExpressionList);
        SubExpression     = FORM_EXPRESSION_FROM_LINK (SubExpressionLink);
        RemoveEntryList(&SubExpression->Link);
        DestroyExpression (SubExpression);
      }
    }
  }

  //
  // Free this Expression
  //
  FreePool(Expression);
}

/**
  Free resources of a storage.

  @param  Storage                Pointer of the storage

**/
VOID
DestroyStorage (
  IN FORMSET_STORAGE   *Storage
  )
{
  if (Storage == NULL) {
    return;
  }

  if (Storage->ConfigRequest != NULL) {
    FreePool(Storage->ConfigRequest);
  }

  FreePool(Storage);
}


/**
  Free resources of a Statement.

  @param  FormSet                Pointer of the FormSet
  @param  Statement              Pointer of the Statement

**/
VOID
DestroyStatement (
  IN     FORM_BROWSER_FORMSET    *FormSet,
  IN OUT FORM_BROWSER_STATEMENT  *Statement
  )
{
  LIST_ENTRY        *Link;
  QUESTION_DEFAULT  *Default;
  QUESTION_OPTION   *Option;
  FORM_EXPRESSION   *Expression;

  //
  // Free Default value List
  //
  while (!IsListEmpty (&Statement->DefaultListHead)) {
    Link = GetFirstNode (&Statement->DefaultListHead);
    Default = QUESTION_DEFAULT_FROM_LINK (Link);
    RemoveEntryList (&Default->Link);

    if (Default->Value.Buffer != NULL) {
      FreePool(Default->Value.Buffer);
    }
    FreePool(Default);
  }

  //
  // Free Options List
  //
  while (!IsListEmpty (&Statement->OptionListHead)) {
    Link = GetFirstNode (&Statement->OptionListHead);
    Option = QUESTION_OPTION_FROM_LINK (Link);
    if (Option->SuppressExpression != NULL) {
      FreePool(Option->SuppressExpression);
    }
    RemoveEntryList (&Option->Link);

    FreePool(Option);
  }

  //
  // Free Inconsistent List
  //
  while (!IsListEmpty (&Statement->InconsistentListHead)) {
    Link = GetFirstNode (&Statement->InconsistentListHead);
    Expression = FORM_EXPRESSION_FROM_LINK (Link);
    RemoveEntryList (&Expression->Link);

    DestroyExpression (Expression);
  }

  //
  // Free NoSubmit List
  //
  while (!IsListEmpty (&Statement->NoSubmitListHead)) {
    Link = GetFirstNode (&Statement->NoSubmitListHead);
    Expression = FORM_EXPRESSION_FROM_LINK (Link);
    RemoveEntryList (&Expression->Link);

    DestroyExpression (Expression);
  }

  //
  // Free WarningIf List
  //
  while (!IsListEmpty (&Statement->WarningListHead)) {
    Link = GetFirstNode (&Statement->WarningListHead);
    Expression = FORM_EXPRESSION_FROM_LINK (Link);
    RemoveEntryList (&Expression->Link);

    DestroyExpression (Expression);
  }

  if (Statement->Expression != NULL) {
    FreePool(Statement->Expression);
  }

  if (Statement->VariableName != NULL) {
    FreePool(Statement->VariableName);
  }
  if (Statement->BlockName != NULL) {
    FreePool(Statement->BlockName);
  }
  if (Statement->BufferValue != NULL) {
    FreePool(Statement->BufferValue);
  }
  if (Statement->Operand == EFI_IFR_STRING_OP || Statement->Operand == EFI_IFR_PASSWORD_OP) {
    DeleteString(Statement->HiiValue.Value.string, FormSet->HiiHandle);
  }
}


/**
  Free resources of a Form.

  @param  FormSet                Pointer of the FormSet
  @param  Form                   Pointer of the Form.

**/
VOID
DestroyForm (
  IN     FORM_BROWSER_FORMSET  *FormSet,
  IN OUT FORM_BROWSER_FORM     *Form
  )
{
  LIST_ENTRY              *Link;
  FORM_EXPRESSION         *Expression;
  FORM_BROWSER_STATEMENT  *Statement;
  FORM_BROWSER_CONFIG_REQUEST  *ConfigInfo;

  //
  // Free Form Expressions
  //
  while (!IsListEmpty (&Form->ExpressionListHead)) {
    Link = GetFirstNode (&Form->ExpressionListHead);
    Expression = FORM_EXPRESSION_FROM_LINK (Link);
    RemoveEntryList (&Expression->Link);

    DestroyExpression (Expression);
  }

  //
  // Free Statements/Questions
  //
  while (!IsListEmpty (&Form->StatementListHead)) {
    Link = GetFirstNode (&Form->StatementListHead);
    Statement = FORM_BROWSER_STATEMENT_FROM_LINK (Link);
    RemoveEntryList (&Statement->Link);

    DestroyStatement (FormSet, Statement);
  }

  //
  // Free ConfigRequest string.
  //
  while (!IsListEmpty (&Form->ConfigRequestHead)) {
    Link = GetFirstNode (&Form->ConfigRequestHead);
    ConfigInfo = FORM_BROWSER_CONFIG_REQUEST_FROM_LINK (Link);
    RemoveEntryList (&ConfigInfo->Link);

    FreePool(ConfigInfo->ConfigRequest);
    FreePool(ConfigInfo);
  }

  if (Form->SuppressExpression != NULL) {
    FreePool(Form->SuppressExpression);
  }

  UiFreeMenuList (&Form->FormViewListHead);

  //
  // Free this Form
  //
  FreePool(Form);
}


/**
  Free resources allocated for a FormSet.

  @param  FormSet                Pointer of the FormSet

**/
VOID
DestroyFormSet (
  IN OUT FORM_BROWSER_FORMSET  *FormSet
  )
{
  LIST_ENTRY            *Link;
  FORMSET_STORAGE       *Storage;
  FORMSET_DEFAULTSTORE  *DefaultStore;
  FORM_EXPRESSION       *Expression;
  FORM_BROWSER_FORM     *Form;

  if (FormSet->IfrBinaryData == NULL) {
    //
    // Uninitialized FormSet
    //
    FreePool(FormSet);
    return;
  }

  //
  // Free IFR binary buffer
  //
  FreePool(FormSet->IfrBinaryData);

  //
  // Free FormSet Storage
  //
  if (FormSet->StorageListHead.ForwardLink != NULL) {
    while (!IsListEmpty (&FormSet->StorageListHead)) {
      Link = GetFirstNode (&FormSet->StorageListHead);
      Storage = FORMSET_STORAGE_FROM_LINK (Link);
      RemoveEntryList (&Storage->Link);

      DestroyStorage (Storage);
    }
  }

  //
  // Free FormSet Default Store
  //
  if (FormSet->DefaultStoreListHead.ForwardLink != NULL) {
    while (!IsListEmpty (&FormSet->DefaultStoreListHead)) {
      Link = GetFirstNode (&FormSet->DefaultStoreListHead);
      DefaultStore = FORMSET_DEFAULTSTORE_FROM_LINK (Link);
      RemoveEntryList (&DefaultStore->Link);

      FreePool(DefaultStore);
    }
  }

  //
  // Free Formset Expressions
  //
  while (!IsListEmpty (&FormSet->ExpressionListHead)) {
    Link = GetFirstNode (&FormSet->ExpressionListHead);
    Expression = FORM_EXPRESSION_FROM_LINK (Link);
    RemoveEntryList (&Expression->Link);

    DestroyExpression (Expression);
  }

  //
  // Free Forms
  //
  if (FormSet->FormListHead.ForwardLink != NULL) {
    while (!IsListEmpty (&FormSet->FormListHead)) {
      Link = GetFirstNode (&FormSet->FormListHead);
      Form = FORM_BROWSER_FORM_FROM_LINK (Link);
      RemoveEntryList (&Form->Link);

      DestroyForm (FormSet, Form);
    }
  }

  if (FormSet->StatementBuffer != NULL) {
    FreePool(FormSet->StatementBuffer);
  }
  if (FormSet->ExpressionBuffer != NULL) {
    FreePool(FormSet->ExpressionBuffer);
  }

  FreePool(FormSet);
}


/**
  Tell whether this Operand is an Expression OpCode or not

  @param  Operand                Operand of an IFR OpCode.

  @retval TRUE                   This is an Expression OpCode.
  @retval FALSE                  Not an Expression OpCode.

**/
BOOLEAN
IsExpressionOpCode (
  IN UINT8              Operand
  )
{
  if (((Operand >= EFI_IFR_EQ_ID_VAL_OP) && (Operand <= EFI_IFR_NOT_OP)) ||
      ((Operand >= EFI_IFR_MATCH_OP) && (Operand <= EFI_IFR_SET_OP))  ||
      ((Operand >= EFI_IFR_EQUAL_OP) && (Operand <= EFI_IFR_SPAN_OP)) ||
      (Operand == EFI_IFR_CATENATE_OP) ||
      (Operand == EFI_IFR_TO_LOWER_OP) ||
      (Operand == EFI_IFR_TO_UPPER_OP) ||
      (Operand == EFI_IFR_MAP_OP)      ||
      (Operand == EFI_IFR_VERSION_OP)  ||
      (Operand == EFI_IFR_SECURITY_OP) ||
      (Operand == EFI_IFR_MATCH2_OP)) {
    return TRUE;
  } else {
    return FALSE;
  }
}

/**
  Tell whether this Operand is an Statement OpCode.

  @param  Operand                Operand of an IFR OpCode.

  @retval TRUE                   This is an Statement OpCode.
  @retval FALSE                  Not an Statement OpCode.

**/
BOOLEAN
IsStatementOpCode (
  IN UINT8              Operand
  )
{
  if ((Operand == EFI_IFR_SUBTITLE_OP) ||
      (Operand == EFI_IFR_TEXT_OP) ||
      (Operand == EFI_IFR_RESET_BUTTON_OP) ||
      (Operand == EFI_IFR_REF_OP) ||
      (Operand == EFI_IFR_ACTION_OP) ||
      (Operand == EFI_IFR_NUMERIC_OP) ||
      (Operand == EFI_IFR_ORDERED_LIST_OP) ||
      (Operand == EFI_IFR_CHECKBOX_OP) ||
      (Operand == EFI_IFR_STRING_OP) ||
      (Operand == EFI_IFR_PASSWORD_OP) ||
      (Operand == EFI_IFR_DATE_OP) ||
      (Operand == EFI_IFR_TIME_OP) ||
      (Operand == EFI_IFR_GUID_OP) ||
      (Operand == EFI_IFR_ONE_OF_OP)) {
    return TRUE;
  } else {
    return FALSE;
  }
}

/**
  Tell whether this Operand is an known OpCode.

  @param  Operand                Operand of an IFR OpCode.

  @retval TRUE                   This is an Statement OpCode.
  @retval FALSE                  Not an Statement OpCode.

**/
BOOLEAN
IsUnKnownOpCode (
  IN UINT8              Operand
  )
{
  return Operand > EFI_IFR_MATCH2_OP ? TRUE : FALSE;
}

/**
  Calculate number of Statemens(Questions) and Expression OpCodes.

  @param  FormSet                The FormSet to be counted.
  @param  NumberOfStatement      Number of Statemens(Questions)
  @param  NumberOfExpression     Number of Expression OpCodes

**/
VOID
CountOpCodes (
  IN  FORM_BROWSER_FORMSET  *FormSet,
  IN OUT  UINT16            *NumberOfStatement,
  IN OUT  UINT16            *NumberOfExpression
  )
{
  UINT16  StatementCount;
  UINT16  ExpressionCount;
  UINT8   *OpCodeData;
  UINTN   Offset;
  UINTN   OpCodeLen;

  Offset = 0;
  StatementCount = 0;
  ExpressionCount = 0;

  while (Offset < FormSet->IfrBinaryLength) {
    OpCodeData = FormSet->IfrBinaryData + Offset;
    OpCodeLen = ((EFI_IFR_OP_HEADER *) OpCodeData)->Length;
    Offset += OpCodeLen;

    if (IsExpressionOpCode (((EFI_IFR_OP_HEADER *) OpCodeData)->OpCode)) {
      ExpressionCount++;
    } else {
      StatementCount++;
    }
  }

  *NumberOfStatement = StatementCount;
  *NumberOfExpression = ExpressionCount;
}



/**
  Parse opcodes in the formset IFR binary.

  @param  FormSet                Pointer of the FormSet data structure.

  @retval EFI_SUCCESS            Opcode parse success.
  @retval Other                  Opcode parse fail.

**/
EFI_STATUS
ParseOpCodes (
  IN FORM_BROWSER_FORMSET              *FormSet
  )
{
  EFI_STATUS              Status;
  FORM_BROWSER_FORM       *CurrentForm;
  FORM_BROWSER_STATEMENT  *CurrentStatement;
  FORM_BROWSER_STATEMENT  *ParentStatement;
  EXPRESSION_OPCODE       *ExpressionOpCode;
  FORM_EXPRESSION         *CurrentExpression;
  UINT8                   Operand;
  UINT8                   Scope;
  UINTN                   OpCodeOffset;
  UINTN                   OpCodeLength;
  UINT8                   *OpCodeData;
  UINT8                   ScopeOpCode;
  FORMSET_STORAGE         *Storage;
  FORMSET_DEFAULTSTORE    *DefaultStore;
  QUESTION_DEFAULT        *CurrentDefault;
  QUESTION_OPTION         *CurrentOption;
  UINT8                   Width;
  UINT16                  NumberOfStatement;
  UINT16                  NumberOfExpression;
  EFI_IMAGE_ID            *ImageId;
  BOOLEAN                 SuppressForQuestion;
  BOOLEAN                 SuppressForOption;
  UINT16                  DepthOfDisable;
  BOOLEAN                 OpCodeDisabled;
  BOOLEAN                 SingleOpCodeExpression;
  BOOLEAN                 InScopeDefault;
  EFI_HII_VALUE           *Value;
  EFI_IFR_FORM_MAP_METHOD *MapMethod;
  UINT8                   MapScopeDepth;
  LIST_ENTRY              *Link;
  FORMSET_STORAGE         *VarStorage;
  LIST_ENTRY              *MapExpressionList;
  EFI_VARSTORE_ID         TempVarstoreId;
  BOOLEAN                 InScopeDisable;
  INTN                    ConditionalExprCount;
  BOOLEAN                 InUnknownScope;
  UINT8                   UnknownDepth;
  FORMSET_DEFAULTSTORE    *PreDefaultStore;
  LIST_ENTRY              *DefaultLink;
  BOOLEAN                 HaveInserted;
  UINT16                  TotalBits;
  BOOLEAN                 QuestionReferBitField;

  SuppressForQuestion      = FALSE;
  SuppressForOption        = FALSE;
  InScopeDisable           = FALSE;
  DepthOfDisable           = 0;
  OpCodeDisabled           = FALSE;
  SingleOpCodeExpression   = FALSE;
  InScopeDefault           = FALSE;
  CurrentExpression        = NULL;
  CurrentDefault           = NULL;
  CurrentOption            = NULL;
  ImageId                  = NULL;
  MapMethod                = NULL;
  MapScopeDepth            = 0;
  Link                     = NULL;
  VarStorage               = NULL;
  MapExpressionList        = NULL;
  TempVarstoreId           = 0;
  ConditionalExprCount     = 0;
  InUnknownScope           = FALSE;
  UnknownDepth             = 0;
  QuestionReferBitField    = FALSE;

  //
  // Get the number of Statements and Expressions
  //
  CountOpCodes (FormSet, &NumberOfStatement, &NumberOfExpression);

  mStatementIndex = 0;
  mUsedQuestionId = 1;
  FormSet->StatementBuffer = AllocateZeroPool (NumberOfStatement * sizeof (FORM_BROWSER_STATEMENT));
  if (FormSet->StatementBuffer == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  mExpressionOpCodeIndex = 0;
  FormSet->ExpressionBuffer = AllocateZeroPool (NumberOfExpression * sizeof (EXPRESSION_OPCODE));
  if (FormSet->ExpressionBuffer == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  InitializeListHead (&FormSet->StatementListOSF);
  InitializeListHead (&FormSet->StorageListHead);
  InitializeListHead (&FormSet->SaveFailStorageListHead);
  InitializeListHead (&FormSet->DefaultStoreListHead);
  InitializeListHead (&FormSet->FormListHead);
  InitializeListHead (&FormSet->ExpressionListHead);
  ResetCurrentExpressionStack ();
  ResetMapExpressionListStack ();

  CurrentForm = NULL;
  CurrentStatement = NULL;
  ParentStatement  = NULL;

  ResetScopeStack ();

  OpCodeOffset = 0;
  while (OpCodeOffset < FormSet->IfrBinaryLength) {
    OpCodeData = FormSet->IfrBinaryData + OpCodeOffset;

    OpCodeLength = ((EFI_IFR_OP_HEADER *) OpCodeData)->Length;
    OpCodeOffset += OpCodeLength;
    Operand = ((EFI_IFR_OP_HEADER *) OpCodeData)->OpCode;
    Scope = ((EFI_IFR_OP_HEADER *) OpCodeData)->Scope;

    if (InUnknownScope) {
      if (Operand == EFI_IFR_END_OP) {
        UnknownDepth --;

        if (UnknownDepth == 0) {
          InUnknownScope = FALSE;
        }
      } else {
        if (Scope != 0) {
          UnknownDepth ++;
        }
      }

      continue;
    }

    if (IsUnKnownOpCode(Operand)) {
      if (Scope != 0) {
        InUnknownScope = TRUE;
        UnknownDepth ++;
      }

      continue;
    }

    //
    // If scope bit set, push onto scope stack
    //
    if (Scope != 0) {
      PushScope (Operand);
    }

    if (OpCodeDisabled) {
      //
      // DisableIf Expression is evaluated to be TRUE, try to find its end.
      // Here only cares the EFI_IFR_DISABLE_IF and EFI_IFR_END
      //
      if (Operand == EFI_IFR_DISABLE_IF_OP) {
        DepthOfDisable++;
      } else if (Operand == EFI_IFR_END_OP) {
        Status = PopScope (&ScopeOpCode);
        if (EFI_ERROR(Status)) {
          return Status;
        }

        if (ScopeOpCode == EFI_IFR_DISABLE_IF_OP) {
          if (DepthOfDisable == 0) {
            InScopeDisable = FALSE;
            OpCodeDisabled = FALSE;
          } else {
            DepthOfDisable--;
          }
        }
      }
      continue;
    }

    if (IsExpressionOpCode (Operand)) {
      ExpressionOpCode = &FormSet->ExpressionBuffer[mExpressionOpCodeIndex];
      mExpressionOpCodeIndex++;

      ExpressionOpCode->Signature = EXPRESSION_OPCODE_SIGNATURE;
      ExpressionOpCode->Operand = Operand;
      Value = &ExpressionOpCode->Value;

      switch (Operand) {
      case EFI_IFR_EQ_ID_VAL_OP:
        CopyMem (&ExpressionOpCode->QuestionId, &((EFI_IFR_EQ_ID_VAL *) OpCodeData)->QuestionId, sizeof (EFI_QUESTION_ID));

        Value->Type = EFI_IFR_TYPE_NUM_SIZE_16;
        CopyMem (&Value->Value.u16, &((EFI_IFR_EQ_ID_VAL *) OpCodeData)->Value, sizeof (UINT16));
        break;

      case EFI_IFR_EQ_ID_ID_OP:
        CopyMem (&ExpressionOpCode->QuestionId, &((EFI_IFR_EQ_ID_ID *) OpCodeData)->QuestionId1, sizeof (EFI_QUESTION_ID));
        CopyMem (&ExpressionOpCode->QuestionId2, &((EFI_IFR_EQ_ID_ID *) OpCodeData)->QuestionId2, sizeof (EFI_QUESTION_ID));
        break;

      case EFI_IFR_EQ_ID_VAL_LIST_OP:
        CopyMem (&ExpressionOpCode->QuestionId, &((EFI_IFR_EQ_ID_VAL_LIST *) OpCodeData)->QuestionId, sizeof (EFI_QUESTION_ID));
        CopyMem (&ExpressionOpCode->ListLength, &((EFI_IFR_EQ_ID_VAL_LIST *) OpCodeData)->ListLength, sizeof (UINT16));
        ExpressionOpCode->ValueList = AllocateCopyPool(ExpressionOpCode->ListLength * sizeof (UINT16), &((EFI_IFR_EQ_ID_VAL_LIST *) OpCodeData)->ValueList);
        break;

      case EFI_IFR_TO_STRING_OP:
      case EFI_IFR_FIND_OP:
        ExpressionOpCode->Format = (( EFI_IFR_TO_STRING *) OpCodeData)->Format;
        break;

      case EFI_IFR_STRING_REF1_OP:
        Value->Type = EFI_IFR_TYPE_STRING;
        CopyMem (&Value->Value.string, &(( EFI_IFR_STRING_REF1 *) OpCodeData)->StringId, sizeof (EFI_STRING_ID));
        break;

      case EFI_IFR_RULE_REF_OP:
        ExpressionOpCode->RuleId = (( EFI_IFR_RULE_REF *) OpCodeData)->RuleId;
        break;

      case EFI_IFR_SPAN_OP:
        ExpressionOpCode->Flags = (( EFI_IFR_SPAN *) OpCodeData)->Flags;
        break;

      case EFI_IFR_THIS_OP:
        ASSERT (ParentStatement != NULL);
        ExpressionOpCode->QuestionId = ParentStatement->QuestionId;
        break;

      case EFI_IFR_SECURITY_OP:
        CopyMem (&ExpressionOpCode->Guid, &((EFI_IFR_SECURITY *) OpCodeData)->Permissions, sizeof (EFI_GUID));
        break;

      case EFI_IFR_MATCH2_OP:
        CopyMem (&ExpressionOpCode->Guid, &((EFI_IFR_MATCH2 *) OpCodeData)->SyntaxType, sizeof (EFI_GUID));
        break;

      case EFI_IFR_GET_OP:
      case EFI_IFR_SET_OP:
        CopyMem (&TempVarstoreId, &((EFI_IFR_GET *) OpCodeData)->VarStoreId, sizeof (TempVarstoreId));
        if (TempVarstoreId != 0) {
          if (FormSet->StorageListHead.ForwardLink != NULL) {
            Link = GetFirstNode (&FormSet->StorageListHead);
            while (!IsNull (&FormSet->StorageListHead, Link)) {
              VarStorage = FORMSET_STORAGE_FROM_LINK (Link);
              if (VarStorage->VarStoreId == ((EFI_IFR_GET *) OpCodeData)->VarStoreId) {
                ExpressionOpCode->VarStorage = VarStorage->BrowserStorage;
                break;
              }
              Link = GetNextNode (&FormSet->StorageListHead, Link);
            }
          }
          if (ExpressionOpCode->VarStorage == NULL) {
            //
            // VarStorage is not found.
            //
            return EFI_INVALID_PARAMETER;
          }
        }
        ExpressionOpCode->ValueType = ((EFI_IFR_GET *) OpCodeData)->VarStoreType;
        switch (ExpressionOpCode->ValueType) {
        case EFI_IFR_TYPE_BOOLEAN:
        case EFI_IFR_TYPE_NUM_SIZE_8:
          ExpressionOpCode->ValueWidth = 1;
          break;

        case EFI_IFR_TYPE_NUM_SIZE_16:
        case EFI_IFR_TYPE_STRING:
          ExpressionOpCode->ValueWidth = 2;
          break;

        case EFI_IFR_TYPE_NUM_SIZE_32:
          ExpressionOpCode->ValueWidth = 4;
          break;

        case EFI_IFR_TYPE_NUM_SIZE_64:
          ExpressionOpCode->ValueWidth = 8;
          break;

        case EFI_IFR_TYPE_DATE:
          ExpressionOpCode->ValueWidth = (UINT8) sizeof (EFI_IFR_DATE);
          break;

        case EFI_IFR_TYPE_TIME:
          ExpressionOpCode->ValueWidth = (UINT8) sizeof (EFI_IFR_TIME);
          break;

        case EFI_IFR_TYPE_REF:
          ExpressionOpCode->ValueWidth = (UINT8) sizeof (EFI_IFR_REF);
          break;

        case EFI_IFR_TYPE_OTHER:
        case EFI_IFR_TYPE_UNDEFINED:
        case EFI_IFR_TYPE_ACTION:
        case EFI_IFR_TYPE_BUFFER:
        default:
          //
          // Invalid value type for Get/Set opcode.
          //
          return EFI_INVALID_PARAMETER;
        }
        CopyMem (&ExpressionOpCode->VarStoreInfo.VarName,   &((EFI_IFR_GET *) OpCodeData)->VarStoreInfo.VarName,   sizeof (EFI_STRING_ID));
        CopyMem (&ExpressionOpCode->VarStoreInfo.VarOffset, &((EFI_IFR_GET *) OpCodeData)->VarStoreInfo.VarOffset, sizeof (UINT16));
        if ((ExpressionOpCode->VarStorage != NULL) &&
            (ExpressionOpCode->VarStorage->Type == EFI_HII_VARSTORE_NAME_VALUE ||
             ExpressionOpCode->VarStorage->Type == EFI_HII_VARSTORE_EFI_VARIABLE)) {
          ExpressionOpCode->ValueName = GetToken (ExpressionOpCode->VarStoreInfo.VarName, FormSet->HiiHandle);
          if (ExpressionOpCode->ValueName == NULL) {
            //
            // String ID is invalid.
            //
            return EFI_INVALID_PARAMETER;
          }
        }
        break;

      case EFI_IFR_QUESTION_REF1_OP:
        CopyMem (&ExpressionOpCode->QuestionId, &((EFI_IFR_EQ_ID_VAL_LIST *) OpCodeData)->QuestionId, sizeof (EFI_QUESTION_ID));
        break;

      case EFI_IFR_QUESTION_REF3_OP:
        if (OpCodeLength >= sizeof (EFI_IFR_QUESTION_REF3_2)) {
          CopyMem (&ExpressionOpCode->DevicePath, &(( EFI_IFR_QUESTION_REF3_2 *) OpCodeData)->DevicePath, sizeof (EFI_STRING_ID));

          if (OpCodeLength >= sizeof (EFI_IFR_QUESTION_REF3_3)) {
            CopyMem (&ExpressionOpCode->Guid, &(( EFI_IFR_QUESTION_REF3_3 *) OpCodeData)->Guid, sizeof (EFI_GUID));
          }
        }
        break;

      //
      // constant
      //
      case EFI_IFR_TRUE_OP:
        Value->Type = EFI_IFR_TYPE_BOOLEAN;
        Value->Value.b = TRUE;
        break;

      case EFI_IFR_FALSE_OP:
        Value->Type = EFI_IFR_TYPE_BOOLEAN;
        Value->Value.b = FALSE;
        break;

      case EFI_IFR_ONE_OP:
        Value->Type = EFI_IFR_TYPE_NUM_SIZE_8;
        Value->Value.u8 = 1;
        break;

      case EFI_IFR_ZERO_OP:
        Value->Type = EFI_IFR_TYPE_NUM_SIZE_8;
        Value->Value.u8 = 0;
        break;

      case EFI_IFR_ONES_OP:
        Value->Type = EFI_IFR_TYPE_NUM_SIZE_64;
        Value->Value.u64 = 0xffffffffffffffffULL;
        break;

      case EFI_IFR_UINT8_OP:
        Value->Type = EFI_IFR_TYPE_NUM_SIZE_8;
        Value->Value.u8 = (( EFI_IFR_UINT8 *) OpCodeData)->Value;
        break;

      case EFI_IFR_UINT16_OP:
        Value->Type = EFI_IFR_TYPE_NUM_SIZE_16;
        CopyMem (&Value->Value.u16, &(( EFI_IFR_UINT16 *) OpCodeData)->Value, sizeof (UINT16));
        break;

      case EFI_IFR_UINT32_OP:
        Value->Type = EFI_IFR_TYPE_NUM_SIZE_32;
        CopyMem (&Value->Value.u32, &(( EFI_IFR_UINT32 *) OpCodeData)->Value, sizeof (UINT32));
        break;

      case EFI_IFR_UINT64_OP:
        Value->Type = EFI_IFR_TYPE_NUM_SIZE_64;
        CopyMem (&Value->Value.u64, &(( EFI_IFR_UINT64 *) OpCodeData)->Value, sizeof (UINT64));
        break;

      case EFI_IFR_UNDEFINED_OP:
        Value->Type = EFI_IFR_TYPE_UNDEFINED;
        break;

      case EFI_IFR_VERSION_OP:
        Value->Type = EFI_IFR_TYPE_NUM_SIZE_16;
        Value->Value.u16 = EFI_IFR_SPECIFICATION_VERSION;
        break;

      default:
        break;
      }
      //
      // Create sub expression nested in MAP opcode
      //
      if (CurrentExpression == NULL && MapScopeDepth > 0) {
        CurrentExpression = CreateExpression (CurrentForm, OpCodeData);
        ASSERT (MapExpressionList != NULL);
        InsertTailList (MapExpressionList, &CurrentExpression->Link);
        if (Scope == 0) {
          SingleOpCodeExpression = TRUE;
        }
      }
      ASSERT (CurrentExpression != NULL);
      InsertTailList (&CurrentExpression->OpCodeListHead, &ExpressionOpCode->Link);
      if (Operand == EFI_IFR_MAP_OP) {
        //
        // Store current Map Expression List.
        //
        if (MapExpressionList != NULL) {
          PushMapExpressionList (MapExpressionList);
        }
        //
        // Initialize new Map Expression List.
        //
        MapExpressionList = &ExpressionOpCode->MapExpressionList;
        InitializeListHead (MapExpressionList);
        //
        // Store current expression.
        //
        PushCurrentExpression (CurrentExpression);
        CurrentExpression = NULL;
        MapScopeDepth ++;
      } else if (SingleOpCodeExpression) {
        //
        // There are two cases to indicate the end of an Expression:
        // for single OpCode expression: one Expression OpCode
        // for expression consists of more than one OpCode: EFI_IFR_END
        //
        SingleOpCodeExpression = FALSE;

        if (InScopeDisable && CurrentForm == NULL) {
          //
          // This is DisableIf expression for Form, it should be a constant expression
          //
          Status = EvaluateExpression (FormSet, CurrentForm, CurrentExpression);
          if (EFI_ERROR(Status)) {
            return Status;
          }

          OpCodeDisabled = IsTrue(&CurrentExpression->Result);
        }

        CurrentExpression = NULL;
      }

      continue;
    }

    //
    // Parse the Opcode
    //
    switch (Operand) {

    case EFI_IFR_FORM_SET_OP:
      //
      // Check the formset GUID
      //
      if (CompareMem (&FormSet->Guid, &((EFI_IFR_FORM_SET *) OpCodeData)->Guid, sizeof (EFI_GUID)) != 0) {
        return EFI_INVALID_PARAMETER;
      }

      CopyMem (&FormSet->FormSetTitle, &((EFI_IFR_FORM_SET *) OpCodeData)->FormSetTitle, sizeof (EFI_STRING_ID));
      CopyMem (&FormSet->Help,         &((EFI_IFR_FORM_SET *) OpCodeData)->Help,         sizeof (EFI_STRING_ID));
      FormSet->OpCode = (EFI_IFR_OP_HEADER *) OpCodeData;//save the opcode address of formset

      if (OpCodeLength > OFFSET_OF (EFI_IFR_FORM_SET, Flags)) {
        //
        // The formset OpCode contains ClassGuid
        //
        FormSet->NumberOfClassGuid = (UINT8) (((EFI_IFR_FORM_SET *) OpCodeData)->Flags & 0x3);
        CopyMem (FormSet->ClassGuid, OpCodeData + sizeof (EFI_IFR_FORM_SET), FormSet->NumberOfClassGuid * sizeof (EFI_GUID));
      }
      break;

    case EFI_IFR_FORM_OP:
      //
      // Create a new Form for this FormSet
      //
      CurrentForm = AllocateZeroPool (sizeof (FORM_BROWSER_FORM));
      ASSERT (CurrentForm != NULL);
      CurrentForm->Signature = FORM_BROWSER_FORM_SIGNATURE;
      InitializeListHead (&CurrentForm->ExpressionListHead);
      InitializeListHead (&CurrentForm->StatementListHead);
      InitializeListHead (&CurrentForm->ConfigRequestHead);
      InitializeListHead (&CurrentForm->FormViewListHead);

      CurrentForm->FormType = STANDARD_MAP_FORM_TYPE;
      CopyMem (&CurrentForm->FormId,    &((EFI_IFR_FORM *) OpCodeData)->FormId,    sizeof (UINT16));
      CopyMem (&CurrentForm->FormTitle, &((EFI_IFR_FORM *) OpCodeData)->FormTitle, sizeof (EFI_STRING_ID));

      ConditionalExprCount = GetConditionalExpressionCount(ExpressForm);
      if ( ConditionalExprCount > 0) {
        //
        // Form is inside of suppressif
        //
        CurrentForm->SuppressExpression = (FORM_EXPRESSION_LIST *) AllocatePool(
                                                 (UINTN) (sizeof(FORM_EXPRESSION_LIST) + ((ConditionalExprCount -1) * sizeof(FORM_EXPRESSION *))));
        ASSERT (CurrentForm->SuppressExpression != NULL);
        CurrentForm->SuppressExpression->Count     = (UINTN) ConditionalExprCount;
        CurrentForm->SuppressExpression->Signature = FORM_EXPRESSION_LIST_SIGNATURE;
        CopyMem (CurrentForm->SuppressExpression->Expression, GetConditionalExpressionList(ExpressForm), (UINTN) (sizeof (FORM_EXPRESSION *) * ConditionalExprCount));
      }

      if (Scope != 0) {
        //
        // Enter scope of a Form, suppressif will be used for Question or Option
        //
        SuppressForQuestion = TRUE;
      }

      //
      // Insert into Form list of this FormSet
      //
      InsertTailList (&FormSet->FormListHead, &CurrentForm->Link);
      break;

    case EFI_IFR_FORM_MAP_OP:
      //
      // Create a new Form for this FormSet
      //
      CurrentForm = AllocateZeroPool (sizeof (FORM_BROWSER_FORM));
      ASSERT (CurrentForm != NULL);
      CurrentForm->Signature = FORM_BROWSER_FORM_SIGNATURE;
      InitializeListHead (&CurrentForm->ExpressionListHead);
      InitializeListHead (&CurrentForm->StatementListHead);
      InitializeListHead (&CurrentForm->ConfigRequestHead);
      InitializeListHead (&CurrentForm->FormViewListHead);

      CopyMem (&CurrentForm->FormId, &((EFI_IFR_FORM *) OpCodeData)->FormId, sizeof (UINT16));

      MapMethod = (EFI_IFR_FORM_MAP_METHOD *) (OpCodeData + sizeof (EFI_IFR_FORM_MAP));
      //
      // FormMap Form must contain at least one Map Method.
      //
      if (((EFI_IFR_OP_HEADER *) OpCodeData)->Length < ((UINTN) (UINT8 *) (MapMethod + 1) - (UINTN) OpCodeData)) {
        return EFI_INVALID_PARAMETER;
      }
      //
      // Try to find the standard form map method.
      //
      while (((UINTN) (UINT8 *) MapMethod - (UINTN) OpCodeData) < ((EFI_IFR_OP_HEADER *) OpCodeData)->Length) {
        if (CompareGuid ((EFI_GUID *) (VOID *) &MapMethod->MethodIdentifier, &gEfiHiiStandardFormGuid)) {
          CopyMem (&CurrentForm->FormTitle, &MapMethod->MethodTitle, sizeof (EFI_STRING_ID));
          CurrentForm->FormType = STANDARD_MAP_FORM_TYPE;
          break;
        }
        MapMethod ++;
      }
      //
      // If the standard form map method is not found, the first map method title will be used.
      //
      if (CurrentForm->FormTitle == 0) {
        MapMethod = (EFI_IFR_FORM_MAP_METHOD *) (OpCodeData + sizeof (EFI_IFR_FORM_MAP));
        CopyMem (&CurrentForm->FormTitle, &MapMethod->MethodTitle, sizeof (EFI_STRING_ID));
      }

      ConditionalExprCount = GetConditionalExpressionCount(ExpressForm);
      if ( ConditionalExprCount > 0) {
        //
        // Form is inside of suppressif
        //
        CurrentForm->SuppressExpression = (FORM_EXPRESSION_LIST *) AllocatePool(
                                                 (UINTN) (sizeof(FORM_EXPRESSION_LIST) + ((ConditionalExprCount -1) * sizeof(FORM_EXPRESSION *))));
        ASSERT (CurrentForm->SuppressExpression != NULL);
        CurrentForm->SuppressExpression->Count     = (UINTN) ConditionalExprCount;
        CurrentForm->SuppressExpression->Signature = FORM_EXPRESSION_LIST_SIGNATURE;
        CopyMem (CurrentForm->SuppressExpression->Expression, GetConditionalExpressionList(ExpressForm), (UINTN) (sizeof (FORM_EXPRESSION *) * ConditionalExprCount));
      }

      if (Scope != 0) {
        //
        // Enter scope of a Form, suppressif will be used for Question or Option
        //
        SuppressForQuestion = TRUE;
      }

      //
      // Insert into Form list of this FormSet
      //
      InsertTailList (&FormSet->FormListHead, &CurrentForm->Link);
      break;

    //
    // Storage
    //
    case EFI_IFR_VARSTORE_OP:
      //
      // Create a buffer Storage for this FormSet
      //
      Storage = CreateStorage (FormSet, EFI_HII_VARSTORE_BUFFER, OpCodeData);
      CopyMem (&Storage->VarStoreId, &((EFI_IFR_VARSTORE *) OpCodeData)->VarStoreId, sizeof (EFI_VARSTORE_ID));
      break;

    case EFI_IFR_VARSTORE_NAME_VALUE_OP:
      //
      // Create a name/value Storage for this FormSet
      //
      Storage = CreateStorage (FormSet, EFI_HII_VARSTORE_NAME_VALUE, OpCodeData);
      CopyMem (&Storage->VarStoreId, &((EFI_IFR_VARSTORE_NAME_VALUE *) OpCodeData)->VarStoreId, sizeof (EFI_VARSTORE_ID));
      break;

    case EFI_IFR_VARSTORE_EFI_OP:
      //
      // Create a EFI variable Storage for this FormSet
      //
      if (OpCodeLength < sizeof (EFI_IFR_VARSTORE_EFI)) {
        //
        // Create efi varstore with format follow UEFI spec before 2.3.1.
        //
        Storage = CreateStorage (FormSet, EFI_HII_VARSTORE_EFI_VARIABLE, OpCodeData);
      } else {
        //
        // Create efi varstore with format follow UEFI spec 2.3.1 and later.
        //
        Storage = CreateStorage (FormSet, EFI_HII_VARSTORE_EFI_VARIABLE_BUFFER, OpCodeData);
      }
      CopyMem (&Storage->VarStoreId, &((EFI_IFR_VARSTORE_EFI *) OpCodeData)->VarStoreId, sizeof (EFI_VARSTORE_ID));
      break;

    //
    // DefaultStore
    //
    case EFI_IFR_DEFAULTSTORE_OP:
      HaveInserted = FALSE;
      DefaultStore = AllocateZeroPool (sizeof (FORMSET_DEFAULTSTORE));
      ASSERT (DefaultStore != NULL);
      DefaultStore->Signature = FORMSET_DEFAULTSTORE_SIGNATURE;

      CopyMem (&DefaultStore->DefaultId,   &((EFI_IFR_DEFAULTSTORE *) OpCodeData)->DefaultId,   sizeof (UINT16));
      CopyMem (&DefaultStore->DefaultName, &((EFI_IFR_DEFAULTSTORE *) OpCodeData)->DefaultName, sizeof (EFI_STRING_ID));
      //
      // Insert it to the DefaultStore list of this Formset with ascending order.
      //
      if (!IsListEmpty (&FormSet->DefaultStoreListHead)) {
        DefaultLink = GetFirstNode (&FormSet->DefaultStoreListHead);
        while (!IsNull (&FormSet->DefaultStoreListHead, DefaultLink)) {
          PreDefaultStore = FORMSET_DEFAULTSTORE_FROM_LINK(DefaultLink);
          DefaultLink = GetNextNode (&FormSet->DefaultStoreListHead, DefaultLink);
          if (DefaultStore->DefaultId < PreDefaultStore->DefaultId) {
            InsertTailList (&PreDefaultStore->Link, &DefaultStore->Link);
            HaveInserted = TRUE;
            break;
          }
        }
      }
      if (!HaveInserted) {
        InsertTailList (&FormSet->DefaultStoreListHead, &DefaultStore->Link);
      }
      break;

    //
    // Statements
    //
    case EFI_IFR_SUBTITLE_OP:
      CurrentStatement = CreateStatement (OpCodeData, FormSet, CurrentForm);
      ASSERT (CurrentStatement != NULL);

      CurrentStatement->Flags = ((EFI_IFR_SUBTITLE *) OpCodeData)->Flags;
      CurrentStatement->FakeQuestionId = mUsedQuestionId++;
      break;

    case EFI_IFR_TEXT_OP:
      CurrentStatement = CreateStatement (OpCodeData, FormSet, CurrentForm);
      ASSERT (CurrentStatement != NULL);
      CurrentStatement->FakeQuestionId = mUsedQuestionId++;
      CopyMem (&CurrentStatement->TextTwo, &((EFI_IFR_TEXT *) OpCodeData)->TextTwo, sizeof (EFI_STRING_ID));
      break;

    case EFI_IFR_RESET_BUTTON_OP:
      CurrentStatement = CreateStatement (OpCodeData, FormSet, CurrentForm);
      ASSERT (CurrentStatement != NULL);
      CurrentStatement->FakeQuestionId = mUsedQuestionId++;
      CopyMem (&CurrentStatement->DefaultId, &((EFI_IFR_RESET_BUTTON *) OpCodeData)->DefaultId, sizeof (EFI_DEFAULT_ID));
      break;

    //
    // Questions
    //
    case EFI_IFR_ACTION_OP:
      CurrentStatement = CreateQuestion (OpCodeData, FormSet, CurrentForm);
      ASSERT (CurrentStatement != NULL);
      CurrentStatement->HiiValue.Type = EFI_IFR_TYPE_ACTION;

      if (OpCodeLength == sizeof (EFI_IFR_ACTION_1)) {
        //
        // No QuestionConfig present, so no configuration string will be processed
        //
        CurrentStatement->QuestionConfig = 0;
      } else {
        CopyMem (&CurrentStatement->QuestionConfig, &((EFI_IFR_ACTION *) OpCodeData)->QuestionConfig, sizeof (EFI_STRING_ID));
      }
      break;

    case EFI_IFR_REF_OP:
      CurrentStatement = CreateQuestion (OpCodeData, FormSet, CurrentForm);
      ASSERT (CurrentStatement != NULL);
      Value = &CurrentStatement->HiiValue;
      Value->Type = EFI_IFR_TYPE_REF;
      if (OpCodeLength >= sizeof (EFI_IFR_REF)) {
        CopyMem (&Value->Value.ref.FormId, &((EFI_IFR_REF *) OpCodeData)->FormId, sizeof (EFI_FORM_ID));

        if (OpCodeLength >= sizeof (EFI_IFR_REF2)) {
          CopyMem (&Value->Value.ref.QuestionId, &((EFI_IFR_REF2 *) OpCodeData)->QuestionId, sizeof (EFI_QUESTION_ID));

          if (OpCodeLength >= sizeof (EFI_IFR_REF3)) {
            CopyMem (&Value->Value.ref.FormSetGuid, &((EFI_IFR_REF3 *) OpCodeData)->FormSetId, sizeof (EFI_GUID));

            if (OpCodeLength >= sizeof (EFI_IFR_REF4)) {
              CopyMem (&Value->Value.ref.DevicePath, &((EFI_IFR_REF4 *) OpCodeData)->DevicePath, sizeof (EFI_STRING_ID));
            }
          }
        }
      }
      CurrentStatement->StorageWidth = (UINT16) sizeof (EFI_HII_REF);
      InitializeRequestElement (FormSet, CurrentStatement, CurrentForm);
      break;

    case EFI_IFR_ONE_OF_OP:
    case EFI_IFR_NUMERIC_OP:
      CurrentStatement = CreateQuestion (OpCodeData, FormSet, CurrentForm);
      ASSERT(CurrentStatement != NULL);

      CurrentStatement->Flags = ((EFI_IFR_ONE_OF *) OpCodeData)->Flags;
      Value = &CurrentStatement->HiiValue;

      if (QuestionReferBitField) {
        //
        // Get the bit var store info (bit/byte offset, bit/byte offset)
        //
        CurrentStatement->QuestionReferToBitField = TRUE;
        CurrentStatement->BitStorageWidth = CurrentStatement->Flags & EDKII_IFR_NUMERIC_SIZE_BIT;
        CurrentStatement->BitVarOffset = CurrentStatement->VarStoreInfo.VarOffset;
        CurrentStatement->VarStoreInfo.VarOffset = CurrentStatement->BitVarOffset / 8;
        TotalBits = CurrentStatement->BitVarOffset % 8 + CurrentStatement->BitStorageWidth;
        CurrentStatement->StorageWidth = (TotalBits % 8 == 0? TotalBits / 8: TotalBits / 8 + 1);

        //
        // Get the Minimum/Maximum/Step value(Note: bit field type has been stored as UINT32 type)
        //
        CurrentStatement->Minimum = ((EFI_IFR_NUMERIC *) OpCodeData)->data.u32.MinValue;
        CurrentStatement->Maximum = ((EFI_IFR_NUMERIC *) OpCodeData)->data.u32.MaxValue;
        CurrentStatement->Step    = ((EFI_IFR_NUMERIC *) OpCodeData)->data.u32.Step;

        //
        // Update the Flag and type of Minimum/Maximum/Step according to the actual width of bit field,
        // in order to make Browser handle these question with bit varstore correctly.
        //
        ((EFI_IFR_NUMERIC *) OpCodeData)->Flags &=  EDKII_IFR_DISPLAY_BIT;
        ((EFI_IFR_NUMERIC *) OpCodeData)->Flags >>= 2;
        switch (CurrentStatement->StorageWidth) {
        case 1:
          ((EFI_IFR_NUMERIC *) OpCodeData)->Flags |= EFI_IFR_TYPE_NUM_SIZE_8;
          ((EFI_IFR_NUMERIC *) OpCodeData)->data.u8.MinValue = (UINT8)CurrentStatement->Minimum;
          ((EFI_IFR_NUMERIC *) OpCodeData)->data.u8.MaxValue = (UINT8)CurrentStatement->Maximum;
          ((EFI_IFR_NUMERIC *) OpCodeData)->data.u8.Step = (UINT8)CurrentStatement->Step;
          Value->Type = EFI_IFR_TYPE_NUM_SIZE_8;
          break;
        case 2:
          ((EFI_IFR_NUMERIC *) OpCodeData)->Flags |= EFI_IFR_TYPE_NUM_SIZE_16;
          ((EFI_IFR_NUMERIC *) OpCodeData)->data.u16.MinValue = (UINT16)CurrentStatement->Minimum;
          ((EFI_IFR_NUMERIC *) OpCodeData)->data.u16.MaxValue = (UINT16)CurrentStatement->Maximum;
          ((EFI_IFR_NUMERIC *) OpCodeData)->data.u16.Step = (UINT16)CurrentStatement->Step;
          Value->Type = EFI_IFR_TYPE_NUM_SIZE_16;
          break;
        case 3:
        case 4:
          ((EFI_IFR_NUMERIC *) OpCodeData)->Flags |= EFI_IFR_TYPE_NUM_SIZE_32;
          ((EFI_IFR_NUMERIC *) OpCodeData)->data.u32.MinValue = (UINT32)CurrentStatement->Minimum;
          ((EFI_IFR_NUMERIC *) OpCodeData)->data.u32.MaxValue = (UINT32)CurrentStatement->Maximum;
          ((EFI_IFR_NUMERIC *) OpCodeData)->data.u32.Step = (UINT32)CurrentStatement->Step;
          Value->Type = EFI_IFR_TYPE_NUM_SIZE_32;
          break;
        default:
          break;
        }
      } else {
        switch (CurrentStatement->Flags & EFI_IFR_NUMERIC_SIZE) {
        case EFI_IFR_NUMERIC_SIZE_1:
          CurrentStatement->Minimum = ((EFI_IFR_NUMERIC *) OpCodeData)->data.u8.MinValue;
          CurrentStatement->Maximum = ((EFI_IFR_NUMERIC *) OpCodeData)->data.u8.MaxValue;
          CurrentStatement->Step    = ((EFI_IFR_NUMERIC *) OpCodeData)->data.u8.Step;
          CurrentStatement->StorageWidth = (UINT16) sizeof (UINT8);
          Value->Type = EFI_IFR_TYPE_NUM_SIZE_8;
          break;

        case EFI_IFR_NUMERIC_SIZE_2:
          CopyMem (&CurrentStatement->Minimum, &((EFI_IFR_NUMERIC *) OpCodeData)->data.u16.MinValue, sizeof (UINT16));
          CopyMem (&CurrentStatement->Maximum, &((EFI_IFR_NUMERIC *) OpCodeData)->data.u16.MaxValue, sizeof (UINT16));
          CopyMem (&CurrentStatement->Step,    &((EFI_IFR_NUMERIC *) OpCodeData)->data.u16.Step,     sizeof (UINT16));
          CurrentStatement->StorageWidth = (UINT16) sizeof (UINT16);
          Value->Type = EFI_IFR_TYPE_NUM_SIZE_16;
          break;

        case EFI_IFR_NUMERIC_SIZE_4:
          CopyMem (&CurrentStatement->Minimum, &((EFI_IFR_NUMERIC *) OpCodeData)->data.u32.MinValue, sizeof (UINT32));
          CopyMem (&CurrentStatement->Maximum, &((EFI_IFR_NUMERIC *) OpCodeData)->data.u32.MaxValue, sizeof (UINT32));
          CopyMem (&CurrentStatement->Step,    &((EFI_IFR_NUMERIC *) OpCodeData)->data.u32.Step,     sizeof (UINT32));
          CurrentStatement->StorageWidth = (UINT16) sizeof (UINT32);
          Value->Type = EFI_IFR_TYPE_NUM_SIZE_32;
          break;

        case EFI_IFR_NUMERIC_SIZE_8:
          CopyMem (&CurrentStatement->Minimum, &((EFI_IFR_NUMERIC *) OpCodeData)->data.u64.MinValue, sizeof (UINT64));
          CopyMem (&CurrentStatement->Maximum, &((EFI_IFR_NUMERIC *) OpCodeData)->data.u64.MaxValue, sizeof (UINT64));
          CopyMem (&CurrentStatement->Step,    &((EFI_IFR_NUMERIC *) OpCodeData)->data.u64.Step,     sizeof (UINT64));
          CurrentStatement->StorageWidth = (UINT16) sizeof (UINT64);
          Value->Type = EFI_IFR_TYPE_NUM_SIZE_64;
          break;

        default:
          break;
        }
      }
      InitializeRequestElement (FormSet, CurrentStatement, CurrentForm);

      if ((Operand == EFI_IFR_ONE_OF_OP) && Scope != 0) {
        SuppressForOption = TRUE;
      }
      break;

    case EFI_IFR_ORDERED_LIST_OP:
      CurrentStatement = CreateQuestion (OpCodeData, FormSet, CurrentForm);
      ASSERT(CurrentStatement != NULL);

      CurrentStatement->Flags = ((EFI_IFR_ORDERED_LIST *) OpCodeData)->Flags;
      CurrentStatement->MaxContainers = ((EFI_IFR_ORDERED_LIST *) OpCodeData)->MaxContainers;

      CurrentStatement->HiiValue.Type = EFI_IFR_TYPE_BUFFER;
      CurrentStatement->BufferValue = NULL;

      if (Scope != 0) {
        SuppressForOption = TRUE;
      }
      break;

    case EFI_IFR_CHECKBOX_OP:
      CurrentStatement = CreateQuestion (OpCodeData, FormSet, CurrentForm);
      ASSERT(CurrentStatement != NULL);

      CurrentStatement->Flags = ((EFI_IFR_CHECKBOX *) OpCodeData)->Flags;
      CurrentStatement->StorageWidth = (UINT16) sizeof (BOOLEAN);
      CurrentStatement->HiiValue.Type = EFI_IFR_TYPE_BOOLEAN;

      if (QuestionReferBitField) {
        //
        // Get the bit var store info (bit/byte offset, bit/byte offset)
        //
        CurrentStatement->QuestionReferToBitField = TRUE;
        CurrentStatement->BitStorageWidth = 1;
        CurrentStatement->BitVarOffset = CurrentStatement->VarStoreInfo.VarOffset;
        CurrentStatement->VarStoreInfo.VarOffset = CurrentStatement->BitVarOffset / 8;
        TotalBits = CurrentStatement->BitVarOffset % 8 + CurrentStatement->BitStorageWidth;
        CurrentStatement->StorageWidth = (TotalBits % 8 == 0? TotalBits / 8: TotalBits / 8 + 1);
      }

      InitializeRequestElement (FormSet, CurrentStatement, CurrentForm);

      break;

    case EFI_IFR_STRING_OP:
      CurrentStatement = CreateQuestion (OpCodeData, FormSet, CurrentForm);
      ASSERT (CurrentStatement != NULL);
      //
      // MinSize is the minimum number of characters that can be accepted for this opcode,
      // MaxSize is the maximum number of characters that can be accepted for this opcode.
      // The characters are stored as Unicode, so the storage width should multiply 2.
      //
      CurrentStatement->Minimum = ((EFI_IFR_STRING *) OpCodeData)->MinSize;
      CurrentStatement->Maximum = ((EFI_IFR_STRING *) OpCodeData)->MaxSize;
      CurrentStatement->StorageWidth = (UINT16)((UINTN) CurrentStatement->Maximum * sizeof (CHAR16));
      CurrentStatement->Flags = ((EFI_IFR_STRING *) OpCodeData)->Flags;

      CurrentStatement->HiiValue.Type = EFI_IFR_TYPE_STRING;
      CurrentStatement->BufferValue = AllocateZeroPool (CurrentStatement->StorageWidth + sizeof (CHAR16));
      CurrentStatement->HiiValue.Value.string = NewString ((CHAR16*) CurrentStatement->BufferValue, FormSet->HiiHandle);

      InitializeRequestElement (FormSet, CurrentStatement, CurrentForm);
      break;

    case EFI_IFR_PASSWORD_OP:
      CurrentStatement = CreateQuestion (OpCodeData, FormSet, CurrentForm);
      ASSERT (CurrentStatement != NULL);
      //
      // MinSize is the minimum number of characters that can be accepted for this opcode,
      // MaxSize is the maximum number of characters that can be accepted for this opcode.
      // The characters are stored as Unicode, so the storage width should multiply 2.
      //
      CopyMem (&CurrentStatement->Minimum, &((EFI_IFR_PASSWORD *) OpCodeData)->MinSize, sizeof (UINT16));
      CopyMem (&CurrentStatement->Maximum, &((EFI_IFR_PASSWORD *) OpCodeData)->MaxSize, sizeof (UINT16));
      CurrentStatement->StorageWidth = (UINT16)((UINTN) CurrentStatement->Maximum * sizeof (CHAR16));

      CurrentStatement->HiiValue.Type = EFI_IFR_TYPE_STRING;
      CurrentStatement->BufferValue = AllocateZeroPool ((CurrentStatement->StorageWidth + sizeof (CHAR16)));
      CurrentStatement->HiiValue.Value.string = NewString ((CHAR16*) CurrentStatement->BufferValue, FormSet->HiiHandle);

      InitializeRequestElement (FormSet, CurrentStatement, CurrentForm);
      break;

    case EFI_IFR_DATE_OP:
      CurrentStatement = CreateQuestion (OpCodeData, FormSet, CurrentForm);
      ASSERT(CurrentStatement != NULL);

      CurrentStatement->Flags = ((EFI_IFR_DATE *) OpCodeData)->Flags;
      CurrentStatement->HiiValue.Type = EFI_IFR_TYPE_DATE;

      if ((CurrentStatement->Flags & EFI_QF_DATE_STORAGE) == QF_DATE_STORAGE_NORMAL) {
        CurrentStatement->StorageWidth = (UINT16) sizeof (EFI_HII_DATE);

        InitializeRequestElement (FormSet, CurrentStatement, CurrentForm);
      } else {
        //
        // Don't assign storage for RTC type of date/time
        //
        CurrentStatement->Storage = NULL;
        CurrentStatement->StorageWidth = 0;
      }
      break;

    case EFI_IFR_TIME_OP:
      CurrentStatement = CreateQuestion (OpCodeData, FormSet, CurrentForm);
      ASSERT(CurrentStatement != NULL);

      CurrentStatement->Flags = ((EFI_IFR_TIME *) OpCodeData)->Flags;
      CurrentStatement->HiiValue.Type = EFI_IFR_TYPE_TIME;

      if ((CurrentStatement->Flags & QF_TIME_STORAGE) == QF_TIME_STORAGE_NORMAL) {
        CurrentStatement->StorageWidth = (UINT16) sizeof (EFI_HII_TIME);

        InitializeRequestElement (FormSet, CurrentStatement, CurrentForm);
      } else {
        //
        // Don't assign storage for RTC type of date/time
        //
        CurrentStatement->Storage = NULL;
        CurrentStatement->StorageWidth = 0;
      }
      break;

    //
    // Default
    //
    case EFI_IFR_DEFAULT_OP:
      //
      // EFI_IFR_DEFAULT appear in scope of a Question,
      // It creates a default value for the current question.
      // A Question may have more than one Default value which have different default types.
      //
      CurrentDefault = AllocateZeroPool (sizeof (QUESTION_DEFAULT));
      ASSERT (CurrentDefault != NULL);
      CurrentDefault->Signature = QUESTION_DEFAULT_SIGNATURE;

      CurrentDefault->Value.Type = ((EFI_IFR_DEFAULT *) OpCodeData)->Type;
      CopyMem (&CurrentDefault->DefaultId, &((EFI_IFR_DEFAULT *) OpCodeData)->DefaultId, sizeof (UINT16));
      if (CurrentDefault->Value.Type == EFI_IFR_TYPE_BUFFER) {
        CurrentDefault->Value.BufferLen = (UINT16) (OpCodeLength - OFFSET_OF (EFI_IFR_DEFAULT, Value));
        CurrentDefault->Value.Buffer = AllocateCopyPool(CurrentDefault->Value.BufferLen, &((EFI_IFR_DEFAULT *) OpCodeData)->Value);
        ASSERT (CurrentDefault->Value.Buffer != NULL);
      } else {
        CopyMem (&CurrentDefault->Value.Value, &((EFI_IFR_DEFAULT *) OpCodeData)->Value, OpCodeLength - OFFSET_OF (EFI_IFR_DEFAULT, Value));
        ExtendValueToU64 (&CurrentDefault->Value);
      }

      //
      // Insert to Default Value list of current Question
      //
      InsertTailList (&ParentStatement->DefaultListHead, &CurrentDefault->Link);

      if (Scope != 0) {
        InScopeDefault = TRUE;
      }
      break;

    //
    // Option
    //
    case EFI_IFR_ONE_OF_OPTION_OP:
      ASSERT (ParentStatement != NULL);
      if (ParentStatement->Operand == EFI_IFR_ORDERED_LIST_OP && ((((EFI_IFR_ONE_OF_OPTION *) OpCodeData)->Flags & (EFI_IFR_OPTION_DEFAULT | EFI_IFR_OPTION_DEFAULT_MFG)) != 0)) {
        //
        // It's keep the default value for ordered list opcode.
        //
        CurrentDefault = AllocateZeroPool (sizeof (QUESTION_DEFAULT));
        ASSERT (CurrentDefault != NULL);
        CurrentDefault->Signature = QUESTION_DEFAULT_SIGNATURE;

        CurrentDefault->Value.Type = EFI_IFR_TYPE_BUFFER;
        if ((((EFI_IFR_ONE_OF_OPTION *) OpCodeData)->Flags & EFI_IFR_OPTION_DEFAULT) != 0) {
          CurrentDefault->DefaultId = EFI_HII_DEFAULT_CLASS_STANDARD;
        } else {
          CurrentDefault->DefaultId = EFI_HII_DEFAULT_CLASS_MANUFACTURING;
        }

        CurrentDefault->Value.BufferLen = (UINT16) (OpCodeLength - OFFSET_OF (EFI_IFR_ONE_OF_OPTION, Value));
        CurrentDefault->Value.Buffer = AllocateCopyPool(CurrentDefault->Value.BufferLen, &((EFI_IFR_ONE_OF_OPTION *) OpCodeData)->Value);
        ASSERT (CurrentDefault->Value.Buffer != NULL);

        //
        // Insert to Default Value list of current Question
        //
        InsertTailList (&ParentStatement->DefaultListHead, &CurrentDefault->Link);
        break;
      }

      //
      // EFI_IFR_ONE_OF_OPTION appear in scope of a Question.
      // It create a selection for use in current Question.
      //
      CurrentOption = AllocateZeroPool (sizeof (QUESTION_OPTION));
      ASSERT (CurrentOption != NULL);
      CurrentOption->Signature = QUESTION_OPTION_SIGNATURE;
      CurrentOption->OpCode    = (EFI_IFR_ONE_OF_OPTION *) OpCodeData;

      CurrentOption->Flags = ((EFI_IFR_ONE_OF_OPTION *) OpCodeData)->Flags;
      CurrentOption->Value.Type = ((EFI_IFR_ONE_OF_OPTION *) OpCodeData)->Type;
      CopyMem (&CurrentOption->Text, &((EFI_IFR_ONE_OF_OPTION *) OpCodeData)->Option, sizeof (EFI_STRING_ID));
      CopyMem (&CurrentOption->Value.Value, &((EFI_IFR_ONE_OF_OPTION *) OpCodeData)->Value, OpCodeLength - OFFSET_OF (EFI_IFR_ONE_OF_OPTION, Value));
      ExtendValueToU64 (&CurrentOption->Value);

      ConditionalExprCount = GetConditionalExpressionCount(ExpressOption);
      if ( ConditionalExprCount > 0) {
        //
        // Form is inside of suppressif
        //
        CurrentOption->SuppressExpression = (FORM_EXPRESSION_LIST *) AllocatePool(
                                                 (UINTN) (sizeof(FORM_EXPRESSION_LIST) + ((ConditionalExprCount -1) * sizeof(FORM_EXPRESSION *))));
        ASSERT (CurrentOption->SuppressExpression != NULL);
        CurrentOption->SuppressExpression->Count     = (UINTN) ConditionalExprCount;
        CurrentOption->SuppressExpression->Signature = FORM_EXPRESSION_LIST_SIGNATURE;
        CopyMem (CurrentOption->SuppressExpression->Expression, GetConditionalExpressionList(ExpressOption), (UINTN) (sizeof (FORM_EXPRESSION *) * ConditionalExprCount));
      }

      //
      // Insert to Option list of current Question
      //
      InsertTailList (&ParentStatement->OptionListHead, &CurrentOption->Link);
      //
      // Now we know the Storage width of nested Ordered List
      //
      if ((ParentStatement->Operand == EFI_IFR_ORDERED_LIST_OP) && (ParentStatement->BufferValue == NULL)) {
        Width = 1;
        switch (CurrentOption->Value.Type) {
        case EFI_IFR_TYPE_NUM_SIZE_8:
          Width = 1;
          break;

        case EFI_IFR_TYPE_NUM_SIZE_16:
          Width = 2;
          break;

        case EFI_IFR_TYPE_NUM_SIZE_32:
          Width = 4;
          break;

        case EFI_IFR_TYPE_NUM_SIZE_64:
          Width = 8;
          break;

        default:
          //
          // Invalid type for Ordered List
          //
          break;
        }

        ParentStatement->StorageWidth = (UINT16) (ParentStatement->MaxContainers * Width);
        ParentStatement->BufferValue = AllocateZeroPool (ParentStatement->StorageWidth);
        ParentStatement->ValueType = CurrentOption->Value.Type;
        if (ParentStatement->HiiValue.Type == EFI_IFR_TYPE_BUFFER) {
          ParentStatement->HiiValue.Buffer = ParentStatement->BufferValue;
          ParentStatement->HiiValue.BufferLen = ParentStatement->StorageWidth;
        }

        InitializeRequestElement (FormSet, ParentStatement, CurrentForm);
      }
      break;

    //
    // Conditional
    //
    case EFI_IFR_NO_SUBMIT_IF_OP:
    case EFI_IFR_INCONSISTENT_IF_OP:
      //
      // Create an Expression node
      //
      CurrentExpression = CreateExpression (CurrentForm, OpCodeData);
      CopyMem (&CurrentExpression->Error, &((EFI_IFR_INCONSISTENT_IF *) OpCodeData)->Error, sizeof (EFI_STRING_ID));

      if (Operand == EFI_IFR_NO_SUBMIT_IF_OP) {
        CurrentExpression->Type = EFI_HII_EXPRESSION_NO_SUBMIT_IF;
        InsertTailList (&ParentStatement->NoSubmitListHead, &CurrentExpression->Link);
      } else {
        CurrentExpression->Type = EFI_HII_EXPRESSION_INCONSISTENT_IF;
        InsertTailList (&ParentStatement->InconsistentListHead, &CurrentExpression->Link);
      }

      //
      // Take a look at next OpCode to see whether current expression consists
      // of single OpCode
      //
      if (((EFI_IFR_OP_HEADER *) (OpCodeData + OpCodeLength))->Scope == 0) {
        SingleOpCodeExpression = TRUE;
      }
      break;

    case EFI_IFR_WARNING_IF_OP:
      //
      // Create an Expression node
      //
      CurrentExpression = CreateExpression (CurrentForm, OpCodeData);
      CopyMem (&CurrentExpression->Error, &((EFI_IFR_WARNING_IF *) OpCodeData)->Warning, sizeof (EFI_STRING_ID));
      CurrentExpression->TimeOut = ((EFI_IFR_WARNING_IF *) OpCodeData)->TimeOut;
      CurrentExpression->Type    = EFI_HII_EXPRESSION_WARNING_IF;
      InsertTailList (&ParentStatement->WarningListHead, &CurrentExpression->Link);

      //
      // Take a look at next OpCode to see whether current expression consists
      // of single OpCode
      //
      if (((EFI_IFR_OP_HEADER *) (OpCodeData + OpCodeLength))->Scope == 0) {
        SingleOpCodeExpression = TRUE;
      }
      break;

    case EFI_IFR_SUPPRESS_IF_OP:
      //
      // Question and Option will appear in scope of this OpCode
      //
      CurrentExpression = CreateExpression (CurrentForm, OpCodeData);
      CurrentExpression->Type = EFI_HII_EXPRESSION_SUPPRESS_IF;

      if (CurrentForm == NULL) {
        InsertTailList (&FormSet->ExpressionListHead, &CurrentExpression->Link);
      } else {
        InsertTailList (&CurrentForm->ExpressionListHead, &CurrentExpression->Link);
      }

      if (SuppressForOption) {
        PushConditionalExpression(CurrentExpression, ExpressOption);
      } else if (SuppressForQuestion) {
        PushConditionalExpression(CurrentExpression, ExpressStatement);
      } else {
        PushConditionalExpression(CurrentExpression, ExpressForm);
      }

      //
      // Take a look at next OpCode to see whether current expression consists
      // of single OpCode
      //
      if (((EFI_IFR_OP_HEADER *) (OpCodeData + OpCodeLength))->Scope == 0) {
        SingleOpCodeExpression = TRUE;
      }
      break;

    case EFI_IFR_GRAY_OUT_IF_OP:
      //
      // Questions will appear in scope of this OpCode
      //
      CurrentExpression = CreateExpression (CurrentForm, OpCodeData);
      CurrentExpression->Type = EFI_HII_EXPRESSION_GRAY_OUT_IF;
      InsertTailList (&CurrentForm->ExpressionListHead, &CurrentExpression->Link);
      PushConditionalExpression(CurrentExpression, ExpressStatement);

      //
      // Take a look at next OpCode to see whether current expression consists
      // of single OpCode
      //
      if (((EFI_IFR_OP_HEADER *) (OpCodeData + OpCodeLength))->Scope == 0) {
        SingleOpCodeExpression = TRUE;
      }
      break;

    case EFI_IFR_DISABLE_IF_OP:
      //
      // The DisableIf expression should only rely on constant, so it could be
      // evaluated at initialization and it will not be queued
      //
      CurrentExpression = AllocateZeroPool (sizeof (FORM_EXPRESSION));
      ASSERT (CurrentExpression != NULL);
      CurrentExpression->Signature = FORM_EXPRESSION_SIGNATURE;
      CurrentExpression->Type = EFI_HII_EXPRESSION_DISABLE_IF;
      InitializeListHead (&CurrentExpression->OpCodeListHead);

      if (CurrentForm != NULL) {
        //
        // This is DisableIf for Question, enqueue it to Form expression list
        //
        InsertTailList (&CurrentForm->ExpressionListHead, &CurrentExpression->Link);
        PushConditionalExpression(CurrentExpression, ExpressStatement);
      }

      OpCodeDisabled  = FALSE;
      InScopeDisable  = TRUE;
      //
      // Take a look at next OpCode to see whether current expression consists
      // of single OpCode
      //
      if (((EFI_IFR_OP_HEADER *) (OpCodeData + OpCodeLength))->Scope == 0) {
        SingleOpCodeExpression = TRUE;
      }
      break;

    //
    // Expression
    //
    case EFI_IFR_VALUE_OP:
      CurrentExpression = CreateExpression (CurrentForm, OpCodeData);
      CurrentExpression->Type = EFI_HII_EXPRESSION_VALUE;
      InsertTailList (&CurrentForm->ExpressionListHead, &CurrentExpression->Link);

      if (InScopeDefault) {
        //
        // Used for default (EFI_IFR_DEFAULT)
        //
        CurrentDefault->ValueExpression = CurrentExpression;
      } else {
        //
        // If used for a question, then the question will be read-only
        //
        //
        // Make sure CurrentStatement is not NULL.
        // If it is NULL, 1) ParseOpCodes functions may parse the IFR wrongly. Or 2) the IFR
        // file is wrongly generated by tools such as VFR Compiler. There may be a bug in VFR Compiler.
        //
        ASSERT (ParentStatement != NULL);
        ParentStatement->ValueExpression = CurrentExpression;
      }

      //
      // Take a look at next OpCode to see whether current expression consists
      // of single OpCode
      //
      if (((EFI_IFR_OP_HEADER *) (OpCodeData + OpCodeLength))->Scope == 0) {
        SingleOpCodeExpression = TRUE;
      }
      break;

    case EFI_IFR_RULE_OP:
      CurrentExpression = CreateExpression (CurrentForm, OpCodeData);
      CurrentExpression->Type = EFI_HII_EXPRESSION_RULE;

      CurrentExpression->RuleId = ((EFI_IFR_RULE *) OpCodeData)->RuleId;
      InsertTailList (&CurrentForm->ExpressionListHead, &CurrentExpression->Link);

      //
      // Take a look at next OpCode to see whether current expression consists
      // of single OpCode
      //
      if (((EFI_IFR_OP_HEADER *) (OpCodeData + OpCodeLength))->Scope == 0) {
        SingleOpCodeExpression = TRUE;
      }
      break;

    case EFI_IFR_READ_OP:
      CurrentExpression = CreateExpression (CurrentForm, OpCodeData);
      CurrentExpression->Type = EFI_HII_EXPRESSION_READ;
      InsertTailList (&CurrentForm->ExpressionListHead, &CurrentExpression->Link);

      //
      // Make sure CurrentStatement is not NULL.
      // If it is NULL, 1) ParseOpCodes functions may parse the IFR wrongly. Or 2) the IFR
      // file is wrongly generated by tools such as VFR Compiler. There may be a bug in VFR Compiler.
      //
      ASSERT (ParentStatement != NULL);
      ParentStatement->ReadExpression = CurrentExpression;

      //
      // Take a look at next OpCode to see whether current expression consists
      // of single OpCode
      //
      if (((EFI_IFR_OP_HEADER *) (OpCodeData + OpCodeLength))->Scope == 0) {
        SingleOpCodeExpression = TRUE;
      }
      break;

    case EFI_IFR_WRITE_OP:
      CurrentExpression = CreateExpression (CurrentForm, OpCodeData);
      CurrentExpression->Type = EFI_HII_EXPRESSION_WRITE;
      InsertTailList (&CurrentForm->ExpressionListHead, &CurrentExpression->Link);

      //
      // Make sure CurrentStatement is not NULL.
      // If it is NULL, 1) ParseOpCodes functions may parse the IFR wrongly. Or 2) the IFR
      // file is wrongly generated by tools such as VFR Compiler. There may be a bug in VFR Compiler.
      //
      ASSERT (ParentStatement != NULL);
      ParentStatement->WriteExpression = CurrentExpression;

      //
      // Take a look at next OpCode to see whether current expression consists
      // of single OpCode
      //
      if (((EFI_IFR_OP_HEADER *) (OpCodeData + OpCodeLength))->Scope == 0) {
        SingleOpCodeExpression = TRUE;
      }
      break;

    //
    // Image
    //
    case EFI_IFR_IMAGE_OP:
      //
      // Get ScopeOpcode from top of stack
      //
      PopScope (&ScopeOpCode);
      PushScope (ScopeOpCode);

      switch (ScopeOpCode) {
      case EFI_IFR_FORM_SET_OP:
        ImageId = &FormSet->ImageId;
        break;

      case EFI_IFR_FORM_OP:
      case EFI_IFR_FORM_MAP_OP:
        ASSERT (CurrentForm != NULL);
        ImageId = &CurrentForm->ImageId;
        break;

      case EFI_IFR_ONE_OF_OPTION_OP:
        ASSERT (CurrentOption != NULL);
        ImageId = &CurrentOption->ImageId;
        break;

      default:
        //
        // Make sure CurrentStatement is not NULL.
        // If it is NULL, 1) ParseOpCodes functions may parse the IFR wrongly. Or 2) the IFR
        // file is wrongly generated by tools such as VFR Compiler.
        //
        ASSERT (ParentStatement != NULL);
        ImageId = &ParentStatement->ImageId;
        break;
      }

      ASSERT (ImageId != NULL);
      CopyMem (ImageId, &((EFI_IFR_IMAGE *) OpCodeData)->Id, sizeof (EFI_IMAGE_ID));
      break;

    //
    // Refresh
    //
    case EFI_IFR_REFRESH_OP:
      ASSERT (ParentStatement != NULL);
      ParentStatement->RefreshInterval = ((EFI_IFR_REFRESH *) OpCodeData)->RefreshInterval;
      break;

    //
    // Refresh guid.
    //
    case EFI_IFR_REFRESH_ID_OP:
      //
      // Get ScopeOpcode from top of stack
      //
      PopScope (&ScopeOpCode);
      PushScope (ScopeOpCode);

      switch (ScopeOpCode) {
      case EFI_IFR_FORM_OP:
      case EFI_IFR_FORM_MAP_OP:
        ASSERT (CurrentForm != NULL);
        CopyMem (&CurrentForm->RefreshGuid, &((EFI_IFR_REFRESH_ID *) OpCodeData)->RefreshEventGroupId, sizeof (EFI_GUID));
        break;

      default:
        ASSERT (ParentStatement != NULL);
        CopyMem (&ParentStatement->RefreshGuid, &((EFI_IFR_REFRESH_ID *) OpCodeData)->RefreshEventGroupId, sizeof (EFI_GUID));
        break;
      }
      break;

    //
    // Modal tag
    //
    case EFI_IFR_MODAL_TAG_OP:
      ASSERT (CurrentForm != NULL);
      CurrentForm->ModalForm = TRUE;
      break;

    //
    // Lock tag, used by form and statement.
    //
    case EFI_IFR_LOCKED_OP:
      //
      // Get ScopeOpcode from top of stack
      //
      PopScope (&ScopeOpCode);
      PushScope (ScopeOpCode);
      switch (ScopeOpCode) {
      case EFI_IFR_FORM_OP:
      case EFI_IFR_FORM_MAP_OP:
        ASSERT (CurrentForm != NULL);
        CurrentForm->Locked = TRUE;
        break;

      default:
        ASSERT (ParentStatement != NULL);
        ParentStatement->Locked = TRUE;
      }
      break;

    //
    // Vendor specific
    //
    case EFI_IFR_GUID_OP:
      CurrentStatement = CreateStatement (OpCodeData, FormSet, CurrentForm);
      if (CompareGuid ((EFI_GUID *)(OpCodeData + sizeof (EFI_IFR_OP_HEADER)), &gEdkiiIfrBitVarstoreGuid)) {
        Scope = 0;
        QuestionReferBitField = TRUE;
      }
      break;

    //
    // Scope End
    //
    case EFI_IFR_END_OP:
      QuestionReferBitField = FALSE;
      Status = PopScope (&ScopeOpCode);
      if (EFI_ERROR(Status)) {
        ResetScopeStack ();
        return Status;
      }

      //
      // Parent statement end tag found, update ParentStatement info.
      //
      if (IsStatementOpCode(ScopeOpCode) && (ParentStatement != NULL) && (ParentStatement->Operand == ScopeOpCode)) {
        ParentStatement  = ParentStatement->ParentStatement;
      }

      switch (ScopeOpCode) {
      case EFI_IFR_FORM_SET_OP:
        //
        // End of FormSet, update FormSet IFR binary length
        // to stop parsing substantial OpCodes
        //
        FormSet->IfrBinaryLength = OpCodeOffset;
        break;

      case EFI_IFR_FORM_OP:
      case EFI_IFR_FORM_MAP_OP:
        //
        // End of Form
        //
        CurrentForm = NULL;
        SuppressForQuestion = FALSE;
        break;

      case EFI_IFR_ONE_OF_OPTION_OP:
        //
        // End of Option
        //
        CurrentOption = NULL;
        break;

      case EFI_IFR_NO_SUBMIT_IF_OP:
      case EFI_IFR_INCONSISTENT_IF_OP:
      case EFI_IFR_WARNING_IF_OP:
        //
        // Ignore end of EFI_IFR_NO_SUBMIT_IF and EFI_IFR_INCONSISTENT_IF
        //
        break;

      case EFI_IFR_SUPPRESS_IF_OP:
        if (SuppressForOption) {
          PopConditionalExpression(ExpressOption);
        } else if (SuppressForQuestion) {
          PopConditionalExpression(ExpressStatement);
        } else {
          PopConditionalExpression(ExpressForm);
        }
        break;

      case EFI_IFR_GRAY_OUT_IF_OP:
        PopConditionalExpression(ExpressStatement);
        break;

      case EFI_IFR_DISABLE_IF_OP:
        if (CurrentForm != NULL) {
          PopConditionalExpression(ExpressStatement);
        }
        InScopeDisable = FALSE;
        OpCodeDisabled = FALSE;
        break;

      case EFI_IFR_ONE_OF_OP:
      case EFI_IFR_ORDERED_LIST_OP:
        SuppressForOption = FALSE;
        break;

      case EFI_IFR_DEFAULT_OP:
        InScopeDefault = FALSE;
        break;

      case EFI_IFR_MAP_OP:
        //
        // Get current Map Expression List.
        //
        Status = PopMapExpressionList ((VOID **) &MapExpressionList);
        if (Status == EFI_ACCESS_DENIED) {
          MapExpressionList = NULL;
        }
        //
        // Get current expression.
        //
        Status = PopCurrentExpression ((VOID **) &CurrentExpression);
        ASSERT_EFI_ERROR(Status);
        ASSERT (MapScopeDepth > 0);
        MapScopeDepth --;
        break;

      default:
        if (IsExpressionOpCode (ScopeOpCode)) {
          if (InScopeDisable && CurrentForm == NULL) {
            //
            // This is DisableIf expression for Form, it should be a constant expression
            //
            ASSERT (CurrentExpression != NULL);
            Status = EvaluateExpression (FormSet, CurrentForm, CurrentExpression);
            if (EFI_ERROR(Status)) {
              return Status;
            }

            OpCodeDisabled = IsTrue (&CurrentExpression->Result);

            //
            // DisableIf Expression is only used once and not queued, free it
            //
            DestroyExpression (CurrentExpression);
          }

          //
          // End of current Expression
          //
          CurrentExpression = NULL;
        }
        break;
      }
      break;

    default:
      break;
    }

    if (IsStatementOpCode(Operand)) {
      CurrentStatement->ParentStatement = ParentStatement;
      if (Scope != 0) {
        //
        // Scope != 0, other statements or options may nest in this statement.
        // Update the ParentStatement info.
        //
        ParentStatement = CurrentStatement;
      }
    }
  }

  return EFI_SUCCESS;
}