Presentation.c

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#include "Setup.h"
 
BOOLEAN                   mHiiPackageListUpdated;
UI_MENU_SELECTION         *gCurrentSelection;
EFI_HII_HANDLE            mCurrentHiiHandle   = NULL;
EFI_GUID                  mCurrentFormSetGuid = {
  0, 0, 0, { 0, 0, 0, 0, 0, 0, 0, 0 }
};
UINT16                    mCurrentFormId     = 0;
EFI_EVENT                 mValueChangedEvent = NULL;
LIST_ENTRY                mRefreshEventList  = INITIALIZE_LIST_HEAD_VARIABLE (mRefreshEventList);
UINT16                    mCurFakeQestId;
FORM_DISPLAY_ENGINE_FORM  gDisplayFormData;
BOOLEAN                   mFinishRetrieveCall = FALSE;
 
EFI_STATUS
CheckConfigAccess (
  IN FORM_BROWSER_FORMSET  *FormSet
  )
{
  EFI_STATUS  Status;
 
  Status = gBS->HandleProtocol (
                  FormSet->DriverHandle,
                  &gEfiHiiConfigAccessProtocolGuid,
                  (VOID **)&FormSet->ConfigAccess
                  );
  if (EFI_ERROR (Status)) {
    //
    // Configuration Driver don't attach ConfigAccess protocol to its HII package
    // list, then there will be no configuration action required.
    // Or the ConfigAccess protocol has been uninstalled.
    //
    FormSet->ConfigAccess = NULL;
  }
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
EvaluateFormExpressions (
  IN FORM_BROWSER_FORMSET  *FormSet,
  IN FORM_BROWSER_FORM     *Form
  )
{
  EFI_STATUS       Status;
  LIST_ENTRY       *Link;
  FORM_EXPRESSION  *Expression;
 
  Link = GetFirstNode (&Form->ExpressionListHead);
  while (!IsNull (&Form->ExpressionListHead, Link)) {
    Expression = FORM_EXPRESSION_FROM_LINK (Link);
    Link       = GetNextNode (&Form->ExpressionListHead, Link);
 
    if ((Expression->Type == EFI_HII_EXPRESSION_INCONSISTENT_IF) ||
        (Expression->Type == EFI_HII_EXPRESSION_NO_SUBMIT_IF) ||
        (Expression->Type == EFI_HII_EXPRESSION_WARNING_IF) ||
        (Expression->Type == EFI_HII_EXPRESSION_WRITE) ||
        ((Expression->Type == EFI_HII_EXPRESSION_READ) && (Form->FormType != STANDARD_MAP_FORM_TYPE)))
    {
      //
      // Postpone Form validation to Question editing or Form submitting or Question Write or Question Read for nonstandard form.
      //
      continue;
    }
 
    Status = EvaluateExpression (FormSet, Form, Expression);
    if (EFI_ERROR (Status)) {
      return Status;
    }
  }
 
  return EFI_SUCCESS;
}
 
FORM_DISPLAY_ENGINE_STATEMENT *
GetDisplayStatement (
  IN EFI_IFR_OP_HEADER  *OpCode
  )
{
  FORM_DISPLAY_ENGINE_STATEMENT  *DisplayStatement;
  LIST_ENTRY                     *Link;
 
  Link = GetFirstNode (&gDisplayFormData.StatementListHead);
  while (!IsNull (&gDisplayFormData.StatementListHead, Link)) {
    DisplayStatement = FORM_DISPLAY_ENGINE_STATEMENT_FROM_LINK (Link);
 
    if (DisplayStatement->OpCode == OpCode) {
      return DisplayStatement;
    }
 
    Link = GetNextNode (&gDisplayFormData.StatementListHead, Link);
  }
 
  return NULL;
}
 
VOID
FreeRefreshEvent (
  VOID
  )
{
  LIST_ENTRY                       *Link;
  FORM_BROWSER_REFRESH_EVENT_NODE  *EventNode;
 
  while (!IsListEmpty (&mRefreshEventList)) {
    Link      = GetFirstNode (&mRefreshEventList);
    EventNode = FORM_BROWSER_REFRESH_EVENT_FROM_LINK (Link);
    RemoveEntryList (&EventNode->Link);
 
    gBS->CloseEvent (EventNode->RefreshEvent);
 
    FreePool (EventNode);
  }
}
 
VOID
UpdateStatement (
  IN OUT FORM_BROWSER_STATEMENT  *Statement
  )
{
  GetQuestionValue (gCurrentSelection->FormSet, gCurrentSelection->Form, Statement, GetSetValueWithHiiDriver);
 
  //
  // Reset FormPackage update flag
  //
  mHiiPackageListUpdated = FALSE;
 
  //
  // Question value may be changed, need invoke its Callback()
  //
  ProcessCallBackFunction (gCurrentSelection, gCurrentSelection->FormSet, gCurrentSelection->Form, Statement, EFI_BROWSER_ACTION_RETRIEVE, FALSE);
 
  if (mHiiPackageListUpdated) {
    //
    // Package list is updated, force to reparse IFR binary of target Formset
    //
    mHiiPackageListUpdated    = FALSE;
    gCurrentSelection->Action = UI_ACTION_REFRESH_FORMSET;
  }
}
 
VOID
EFIAPI
RefreshEventNotifyForStatement (
  IN      EFI_EVENT  Event,
  IN      VOID       *Context
  )
{
  FORM_BROWSER_STATEMENT  *Statement;
 
  Statement = (FORM_BROWSER_STATEMENT *)Context;
  UpdateStatement (Statement);
  gBS->SignalEvent (mValueChangedEvent);
}
 
VOID
EFIAPI
RefreshEventNotifyForForm (
  IN      EFI_EVENT  Event,
  IN      VOID       *Context
  )
{
  gCurrentSelection->Action = UI_ACTION_REFRESH_FORMSET;
 
  gBS->SignalEvent (mValueChangedEvent);
}
 
VOID
CreateRefreshEventForStatement (
  IN     FORM_BROWSER_STATEMENT  *Statement
  )
{
  EFI_STATUS                       Status;
  EFI_EVENT                        RefreshEvent;
  FORM_BROWSER_REFRESH_EVENT_NODE  *EventNode;
 
  //
  // If question has refresh guid, create the notify function.
  //
  Status = gBS->CreateEventEx (
                  EVT_NOTIFY_SIGNAL,
                  TPL_CALLBACK,
                  RefreshEventNotifyForStatement,
                  Statement,
                  &Statement->RefreshGuid,
                  &RefreshEvent
                  );
  ASSERT_EFI_ERROR (Status);
 
  EventNode = AllocateZeroPool (sizeof (FORM_BROWSER_REFRESH_EVENT_NODE));
  ASSERT (EventNode != NULL);
  EventNode->RefreshEvent = RefreshEvent;
  InsertTailList (&mRefreshEventList, &EventNode->Link);
}
 
VOID
CreateRefreshEventForForm (
  IN     FORM_BROWSER_FORM  *Form
  )
{
  EFI_STATUS                       Status;
  EFI_EVENT                        RefreshEvent;
  FORM_BROWSER_REFRESH_EVENT_NODE  *EventNode;
 
  //
  // If question has refresh guid, create the notify function.
  //
  Status = gBS->CreateEventEx (
                  EVT_NOTIFY_SIGNAL,
                  TPL_CALLBACK,
                  RefreshEventNotifyForForm,
                  Form,
                  &Form->RefreshGuid,
                  &RefreshEvent
                  );
  ASSERT_EFI_ERROR (Status);
 
  EventNode = AllocateZeroPool (sizeof (FORM_BROWSER_REFRESH_EVENT_NODE));
  ASSERT (EventNode != NULL);
  EventNode->RefreshEvent = RefreshEvent;
  InsertTailList (&mRefreshEventList, &EventNode->Link);
}
 
VOID
InitializeDisplayStatement (
  IN OUT FORM_DISPLAY_ENGINE_STATEMENT  *DisplayStatement,
  IN     FORM_BROWSER_STATEMENT         *Statement
  )
{
  LIST_ENTRY                     *Link;
  QUESTION_OPTION                *Option;
  DISPLAY_QUESTION_OPTION        *DisplayOption;
  FORM_DISPLAY_ENGINE_STATEMENT  *ParentStatement;
 
  DisplayStatement->Signature = FORM_DISPLAY_ENGINE_STATEMENT_SIGNATURE;
  DisplayStatement->Version   = FORM_DISPLAY_ENGINE_STATEMENT_VERSION_1;
  DisplayStatement->OpCode    = Statement->OpCode;
  InitializeListHead (&DisplayStatement->NestStatementList);
  InitializeListHead (&DisplayStatement->OptionListHead);
 
  if ((EvaluateExpressionList (Statement->Expression, FALSE, NULL, NULL) == ExpressGrayOut) || Statement->Locked) {
    DisplayStatement->Attribute |= HII_DISPLAY_GRAYOUT;
  }
 
  if ((Statement->ValueExpression != NULL) || ((Statement->QuestionFlags & EFI_IFR_FLAG_READ_ONLY) != 0)) {
    DisplayStatement->Attribute |= HII_DISPLAY_READONLY;
  }
 
  //
  // Initilize the option list in statement.
  //
  Link = GetFirstNode (&Statement->OptionListHead);
  while (!IsNull (&Statement->OptionListHead, Link)) {
    Option = QUESTION_OPTION_FROM_LINK (Link);
    Link   = GetNextNode (&Statement->OptionListHead, Link);
    if ((Option->SuppressExpression != NULL) &&
        ((EvaluateExpressionList (Option->SuppressExpression, FALSE, NULL, NULL) == ExpressSuppress)))
    {
      continue;
    }
 
    DisplayOption = AllocateZeroPool (sizeof (DISPLAY_QUESTION_OPTION));
    ASSERT (DisplayOption != NULL);
 
    DisplayOption->ImageId      = Option->ImageId;
    DisplayOption->Signature    = DISPLAY_QUESTION_OPTION_SIGNATURE;
    DisplayOption->OptionOpCode = Option->OpCode;
    InsertTailList (&DisplayStatement->OptionListHead, &DisplayOption->Link);
  }
 
  CopyMem (&DisplayStatement->CurrentValue, &Statement->HiiValue, sizeof (EFI_HII_VALUE));
 
  //
  // Some special op code need an extra buffer to save the data.
  // Such as string, password, orderedlist...
  //
  if (Statement->BufferValue != NULL) {
    //
    // Ordered list opcode may not initilized, get default value here.
    //
    if ((Statement->OpCode->OpCode == EFI_IFR_ORDERED_LIST_OP) && (GetArrayData (Statement->BufferValue, Statement->ValueType, 0) == 0)) {
      GetQuestionDefault (gCurrentSelection->FormSet, gCurrentSelection->Form, Statement, 0);
    }
 
    DisplayStatement->CurrentValue.Buffer    = AllocateCopyPool (Statement->StorageWidth, Statement->BufferValue);
    DisplayStatement->CurrentValue.BufferLen = Statement->StorageWidth;
  }
 
  DisplayStatement->SettingChangedFlag = Statement->ValueChanged;
 
  //
  // Get the highlight statement for current form.
  //
  if (((gCurrentSelection->QuestionId != 0) && (Statement->QuestionId == gCurrentSelection->QuestionId)) ||
      ((mCurFakeQestId != 0) && (Statement->FakeQuestionId == mCurFakeQestId)))
  {
    gDisplayFormData.HighLightedStatement = DisplayStatement;
  }
 
  //
  // Create the refresh event process function.
  //
  if (!IsZeroGuid (&Statement->RefreshGuid)) {
    CreateRefreshEventForStatement (Statement);
  }
 
  //
  // For RTC type of date/time, set default refresh interval to be 1 second.
  //
  if (((Statement->Operand == EFI_IFR_DATE_OP) || (Statement->Operand == EFI_IFR_TIME_OP)) && (Statement->Storage == NULL)) {
    Statement->RefreshInterval = 1;
  }
 
  //
  // Create the refresh guid hook event.
  // If the statement in this form has refresh event or refresh interval, browser will create this event for display engine.
  //
  if ((!IsZeroGuid (&Statement->RefreshGuid)) || (Statement->RefreshInterval != 0)) {
    gDisplayFormData.FormRefreshEvent = mValueChangedEvent;
  }
 
  //
  // Save the password check function for later use.
  //
  if (Statement->Operand == EFI_IFR_PASSWORD_OP) {
    DisplayStatement->PasswordCheck = PasswordCheck;
  }
 
  //
  // If this statement is nest in the subtitle, insert to the host statement.
  // else insert to the form it belongs to.
  //
  if (Statement->ParentStatement != NULL) {
    ParentStatement = GetDisplayStatement (Statement->ParentStatement->OpCode);
    ASSERT (ParentStatement != NULL);
    InsertTailList (&ParentStatement->NestStatementList, &DisplayStatement->DisplayLink);
  } else {
    InsertTailList (&gDisplayFormData.StatementListHead, &DisplayStatement->DisplayLink);
  }
}
 
VOID
EFIAPI
RefreshIntervalProcess (
  IN  EFI_EVENT  Event,
  IN  VOID       *Context
  )
{
  FORM_BROWSER_STATEMENT  *Statement;
  LIST_ENTRY              *Link;
 
  Link = GetFirstNode (&gCurrentSelection->Form->StatementListHead);
  while (!IsNull (&gCurrentSelection->Form->StatementListHead, Link)) {
    Statement = FORM_BROWSER_STATEMENT_FROM_LINK (Link);
    Link      = GetNextNode (&gCurrentSelection->Form->StatementListHead, Link);
 
    if (Statement->RefreshInterval == 0) {
      continue;
    }
 
    UpdateStatement (Statement);
  }
 
  gBS->SignalEvent (mValueChangedEvent);
}
 
VOID
UpdateHotkeyList (
  VOID
  )
{
  BROWSER_HOT_KEY  *HotKey;
  BROWSER_HOT_KEY  *CopyKey;
  LIST_ENTRY       *Link;
 
  Link = GetFirstNode (&gBrowserHotKeyList);
  while (!IsNull (&gBrowserHotKeyList, Link)) {
    HotKey = BROWSER_HOT_KEY_FROM_LINK (Link);
 
    CopyKey = AllocateCopyPool (sizeof (BROWSER_HOT_KEY), HotKey);
    ASSERT (CopyKey != NULL);
    CopyKey->KeyData = AllocateCopyPool (sizeof (EFI_INPUT_KEY), HotKey->KeyData);
    ASSERT (CopyKey->KeyData != NULL);
    CopyKey->HelpString = AllocateCopyPool (StrSize (HotKey->HelpString), HotKey->HelpString);
    ASSERT (CopyKey->HelpString != NULL);
 
    InsertTailList (&gDisplayFormData.HotKeyListHead, &CopyKey->Link);
 
    Link = GetNextNode (&gBrowserHotKeyList, Link);
  }
}
 
UINT32
ProcessQuestionExtraAttr (
  IN   EFI_QUESTION_ID  QuestionId
  )
{
  LIST_ENTRY                   *Link;
  QUESTION_ATTRIBUTE_OVERRIDE  *QuestionDesc;
 
  //
  // Return HII_DISPLAY_NONE if input a invalid question id.
  //
  if (QuestionId == 0) {
    return HII_DISPLAY_NONE;
  }
 
  Link = GetFirstNode (&mPrivateData.FormBrowserEx2.OverrideQestListHead);
  while (!IsNull (&mPrivateData.FormBrowserEx2.OverrideQestListHead, Link)) {
    QuestionDesc = FORM_QUESTION_ATTRIBUTE_OVERRIDE_FROM_LINK (Link);
    Link         = GetNextNode (&mPrivateData.FormBrowserEx2.OverrideQestListHead, Link);
 
    if ((QuestionDesc->QuestionId == QuestionId) &&
        (QuestionDesc->FormId     == gCurrentSelection->FormId) &&
        (QuestionDesc->HiiHandle  == gCurrentSelection->Handle) &&
        CompareGuid (&QuestionDesc->FormSetGuid, &gCurrentSelection->FormSetGuid))
    {
      return QuestionDesc->Attribute;
    }
  }
 
  return HII_DISPLAY_NONE;
}
 
VOID
AddStatementToDisplayForm (
  VOID
  )
{
  EFI_STATUS                       Status;
  LIST_ENTRY                       *Link;
  FORM_BROWSER_STATEMENT           *Statement;
  FORM_DISPLAY_ENGINE_STATEMENT    *DisplayStatement;
  UINT8                            MinRefreshInterval;
  EFI_EVENT                        RefreshIntervalEvent;
  FORM_BROWSER_REFRESH_EVENT_NODE  *EventNode;
  BOOLEAN                          FormEditable;
  UINT32                           ExtraAttribute;
 
  MinRefreshInterval = 0;
  FormEditable       = FALSE;
 
  //
  // Process the statement outside the form, these statements are not recognized
  // by browser core.
  //
  Link = GetFirstNode (&gCurrentSelection->FormSet->StatementListOSF);
  while (!IsNull (&gCurrentSelection->FormSet->StatementListOSF, Link)) {
    Statement = FORM_BROWSER_STATEMENT_FROM_LINK (Link);
    Link      = GetNextNode (&gCurrentSelection->FormSet->StatementListOSF, Link);
 
    DisplayStatement = AllocateZeroPool (sizeof (FORM_DISPLAY_ENGINE_STATEMENT));
    ASSERT (DisplayStatement != NULL);
    DisplayStatement->Signature = FORM_DISPLAY_ENGINE_STATEMENT_SIGNATURE;
    DisplayStatement->Version   = FORM_DISPLAY_ENGINE_STATEMENT_VERSION_1;
    DisplayStatement->OpCode    = Statement->OpCode;
 
    InitializeListHead (&DisplayStatement->NestStatementList);
    InitializeListHead (&DisplayStatement->OptionListHead);
 
    InsertTailList (&gDisplayFormData.StatementListOSF, &DisplayStatement->DisplayLink);
  }
 
  //
  // treat formset as statement outside the form,get its opcode.
  //
  DisplayStatement = AllocateZeroPool (sizeof (FORM_DISPLAY_ENGINE_STATEMENT));
  ASSERT (DisplayStatement != NULL);
 
  DisplayStatement->Signature = FORM_DISPLAY_ENGINE_STATEMENT_SIGNATURE;
  DisplayStatement->Version   = FORM_DISPLAY_ENGINE_STATEMENT_VERSION_1;
  DisplayStatement->OpCode    = gCurrentSelection->FormSet->OpCode;
 
  InitializeListHead (&DisplayStatement->NestStatementList);
  InitializeListHead (&DisplayStatement->OptionListHead);
 
  InsertTailList (&gDisplayFormData.StatementListOSF, &DisplayStatement->DisplayLink);
 
  //
  // Process the statement in this form.
  //
  Link = GetFirstNode (&gCurrentSelection->Form->StatementListHead);
  while (!IsNull (&gCurrentSelection->Form->StatementListHead, Link)) {
    Statement = FORM_BROWSER_STATEMENT_FROM_LINK (Link);
    Link      = GetNextNode (&gCurrentSelection->Form->StatementListHead, Link);
 
    //
    // This statement can't be show, skip it.
    //
    if (EvaluateExpressionList (Statement->Expression, FALSE, NULL, NULL) > ExpressGrayOut) {
      continue;
    }
 
    //
    // Check the extra attribute.
    //
    ExtraAttribute = ProcessQuestionExtraAttr (Statement->QuestionId);
    if ((ExtraAttribute & HII_DISPLAY_SUPPRESS) != 0) {
      continue;
    }
 
    DisplayStatement = AllocateZeroPool (sizeof (FORM_DISPLAY_ENGINE_STATEMENT));
    ASSERT (DisplayStatement != NULL);
 
    //
    // Initialize this statement and add it to the display form.
    //
    InitializeDisplayStatement (DisplayStatement, Statement);
 
    //
    // Set the extra attribute.
    //
    DisplayStatement->Attribute |= ExtraAttribute;
 
    if (Statement->Storage != NULL) {
      FormEditable = TRUE;
    }
 
    //
    // Get the minimal refresh interval value for later use.
    //
    if ((Statement->RefreshInterval != 0) &&
        ((MinRefreshInterval == 0) || (Statement->RefreshInterval < MinRefreshInterval)))
    {
      MinRefreshInterval = Statement->RefreshInterval;
    }
  }
 
  //
  // Create the periodic timer for refresh interval statement.
  //
  if (MinRefreshInterval != 0) {
    Status = gBS->CreateEvent (EVT_TIMER | EVT_NOTIFY_SIGNAL, TPL_CALLBACK, RefreshIntervalProcess, NULL, &RefreshIntervalEvent);
    ASSERT_EFI_ERROR (Status);
    Status = gBS->SetTimer (RefreshIntervalEvent, TimerPeriodic, MinRefreshInterval * ONE_SECOND);
    ASSERT_EFI_ERROR (Status);
 
    EventNode = AllocateZeroPool (sizeof (FORM_BROWSER_REFRESH_EVENT_NODE));
    ASSERT (EventNode != NULL);
    EventNode->RefreshEvent = RefreshIntervalEvent;
    InsertTailList (&mRefreshEventList, &EventNode->Link);
  }
 
  //
  // Create the refresh event process function for Form.
  //
  if (!IsZeroGuid (&gCurrentSelection->Form->RefreshGuid)) {
    CreateRefreshEventForForm (gCurrentSelection->Form);
    if (gDisplayFormData.FormRefreshEvent == NULL) {
      gDisplayFormData.FormRefreshEvent = mValueChangedEvent;
    }
  }
 
  //
  // Update hotkey list field.
  //
  if ((gBrowserSettingScope == SystemLevel) || FormEditable) {
    UpdateHotkeyList ();
  }
}
 
VOID
UpdateDataChangedFlag (
  VOID
  )
{
  LIST_ENTRY            *Link;
  FORM_BROWSER_FORMSET  *LocalFormSet;
 
  gDisplayFormData.SettingChangedFlag = FALSE;
 
  if (IsNvUpdateRequiredForForm (gCurrentSelection->Form)) {
    gDisplayFormData.SettingChangedFlag = TRUE;
    return;
  }
 
  //
  // Base on the system level to check whether need to show the NV flag.
  //
  switch (gBrowserSettingScope) {
    case SystemLevel:
      //
      // Check the maintain list to see whether there is any change.
      //
      Link = GetFirstNode (&gBrowserFormSetList);
      while (!IsNull (&gBrowserFormSetList, Link)) {
        LocalFormSet = FORM_BROWSER_FORMSET_FROM_LINK (Link);
        if (IsNvUpdateRequiredForFormSet (LocalFormSet)) {
          gDisplayFormData.SettingChangedFlag = TRUE;
          return;
        }
 
        Link = GetNextNode (&gBrowserFormSetList, Link);
      }
 
      break;
 
    case FormSetLevel:
      if (IsNvUpdateRequiredForFormSet (gCurrentSelection->FormSet)) {
        gDisplayFormData.SettingChangedFlag = TRUE;
        return;
      }
 
      break;
 
    default:
      break;
  }
}
 
VOID
InitializeDisplayFormData (
  VOID
  )
{
  EFI_STATUS  Status;
 
  gDisplayFormData.Signature   = FORM_DISPLAY_ENGINE_FORM_SIGNATURE;
  gDisplayFormData.Version     = FORM_DISPLAY_ENGINE_VERSION_1;
  gDisplayFormData.ImageId     = 0;
  gDisplayFormData.AnimationId = 0;
 
  InitializeListHead (&gDisplayFormData.StatementListHead);
  InitializeListHead (&gDisplayFormData.StatementListOSF);
  InitializeListHead (&gDisplayFormData.HotKeyListHead);
 
  Status = gBS->CreateEvent (
                  EVT_NOTIFY_WAIT,
                  TPL_CALLBACK,
                  EfiEventEmptyFunction,
                  NULL,
                  &mValueChangedEvent
                  );
  ASSERT_EFI_ERROR (Status);
}
 
VOID
FreeHotkeyList (
  VOID
  )
{
  BROWSER_HOT_KEY  *HotKey;
  LIST_ENTRY       *Link;
 
  while (!IsListEmpty (&gDisplayFormData.HotKeyListHead)) {
    Link   = GetFirstNode (&gDisplayFormData.HotKeyListHead);
    HotKey = BROWSER_HOT_KEY_FROM_LINK (Link);
 
    RemoveEntryList (&HotKey->Link);
 
    FreePool (HotKey->KeyData);
    FreePool (HotKey->HelpString);
    FreePool (HotKey);
  }
}
 
VOID
UpdateDisplayFormData (
  VOID
  )
{
  gDisplayFormData.FormTitle = gCurrentSelection->Form->FormTitle;
  gDisplayFormData.FormId    = gCurrentSelection->FormId;
  gDisplayFormData.HiiHandle = gCurrentSelection->Handle;
  CopyGuid (&gDisplayFormData.FormSetGuid, &gCurrentSelection->FormSetGuid);
 
  gDisplayFormData.Attribute  = 0;
  gDisplayFormData.Attribute |= gCurrentSelection->Form->ModalForm ? HII_DISPLAY_MODAL : 0;
  gDisplayFormData.Attribute |= gCurrentSelection->Form->Locked    ? HII_DISPLAY_LOCK  : 0;
 
  gDisplayFormData.FormRefreshEvent     = NULL;
  gDisplayFormData.HighLightedStatement = NULL;
 
  UpdateDataChangedFlag ();
 
  AddStatementToDisplayForm ();
}
 
VOID
FreeStatementData (
  LIST_ENTRY  *StatementList
  )
{
  LIST_ENTRY                     *Link;
  LIST_ENTRY                     *OptionLink;
  FORM_DISPLAY_ENGINE_STATEMENT  *Statement;
  DISPLAY_QUESTION_OPTION        *Option;
 
  //
  // Free Statements/Questions
  //
  while (!IsListEmpty (StatementList)) {
    Link      = GetFirstNode (StatementList);
    Statement = FORM_DISPLAY_ENGINE_STATEMENT_FROM_LINK (Link);
 
    //
    // Free Options List
    //
    while (!IsListEmpty (&Statement->OptionListHead)) {
      OptionLink = GetFirstNode (&Statement->OptionListHead);
      Option     = DISPLAY_QUESTION_OPTION_FROM_LINK (OptionLink);
      RemoveEntryList (&Option->Link);
      FreePool (Option);
    }
 
    //
    // Free nest statement List
    //
    if (!IsListEmpty (&Statement->NestStatementList)) {
      FreeStatementData (&Statement->NestStatementList);
    }
 
    RemoveEntryList (&Statement->DisplayLink);
    FreePool (Statement);
  }
}
 
VOID
FreeDisplayFormData (
  VOID
  )
{
  FreeStatementData (&gDisplayFormData.StatementListHead);
  FreeStatementData (&gDisplayFormData.StatementListOSF);
 
  FreeRefreshEvent ();
 
  FreeHotkeyList ();
}
 
FORM_BROWSER_STATEMENT *
GetBrowserStatement (
  IN FORM_DISPLAY_ENGINE_STATEMENT  *DisplayStatement
  )
{
  FORM_BROWSER_STATEMENT  *Statement;
  LIST_ENTRY              *Link;
 
  Link = GetFirstNode (&gCurrentSelection->Form->StatementListHead);
  while (!IsNull (&gCurrentSelection->Form->StatementListHead, Link)) {
    Statement = FORM_BROWSER_STATEMENT_FROM_LINK (Link);
 
    if (Statement->OpCode == DisplayStatement->OpCode) {
      return Statement;
    }
 
    Link = GetNextNode (&gCurrentSelection->Form->StatementListHead, Link);
  }
 
  return NULL;
}
 
VOID
UpdateStatementStatusForForm (
  IN FORM_BROWSER_FORMSET  *FormSet,
  IN FORM_BROWSER_FORM     *Form
  )
{
  LIST_ENTRY              *Link;
  FORM_BROWSER_STATEMENT  *Question;
 
  Link = GetFirstNode (&Form->StatementListHead);
  while (!IsNull (&Form->StatementListHead, Link)) {
    Question = FORM_BROWSER_STATEMENT_FROM_LINK (Link);
    Link     = GetNextNode (&Form->StatementListHead, Link);
 
    //
    // For password opcode, not set the the value changed flag.
    //
    if (Question->Operand == EFI_IFR_PASSWORD_OP) {
      continue;
    }
 
    IsQuestionValueChanged (FormSet, Form, Question, GetSetValueWithBuffer);
  }
}
 
VOID
UpdateStatementStatusForFormSet (
  IN FORM_BROWSER_FORMSET  *FormSet
  )
{
  LIST_ENTRY         *Link;
  FORM_BROWSER_FORM  *Form;
 
  Link = GetFirstNode (&FormSet->FormListHead);
  while (!IsNull (&FormSet->FormListHead, Link)) {
    Form = FORM_BROWSER_FORM_FROM_LINK (Link);
    Link = GetNextNode (&FormSet->FormListHead, Link);
 
    UpdateStatementStatusForForm (FormSet, Form);
  }
}
 
VOID
UpdateStatementStatus (
  IN FORM_BROWSER_FORMSET   *FormSet,
  IN FORM_BROWSER_FORM      *Form,
  IN BROWSER_SETTING_SCOPE  SettingScope
  )
{
  LIST_ENTRY            *Link;
  FORM_BROWSER_FORMSET  *LocalFormSet;
 
  switch (SettingScope) {
    case SystemLevel:
      Link = GetFirstNode (&gBrowserFormSetList);
      while (!IsNull (&gBrowserFormSetList, Link)) {
        LocalFormSet = FORM_BROWSER_FORMSET_FROM_LINK (Link);
        Link         = GetNextNode (&gBrowserFormSetList, Link);
        if (!ValidateFormSet (LocalFormSet)) {
          continue;
        }
 
        UpdateStatementStatusForFormSet (LocalFormSet);
      }
 
      break;
 
    case FormSetLevel:
      UpdateStatementStatusForFormSet (FormSet);
      break;
 
    case FormLevel:
      UpdateStatementStatusForForm (FormSet, Form);
      break;
 
    default:
      break;
  }
}
 
EFI_STATUS
ProcessAction (
  IN UINT32  Action,
  IN UINT16  DefaultId
  )
{
  //
  // This is caused by use press ESC, and it should not combine with other action type.
  //
  if ((Action & BROWSER_ACTION_FORM_EXIT) == BROWSER_ACTION_FORM_EXIT) {
    FindNextMenu (gCurrentSelection, FormLevel);
    return EFI_SUCCESS;
  }
 
  //
  // Below is normal hotkey trigged action, these action maybe combine with each other.
  //
  if ((Action & BROWSER_ACTION_DISCARD) == BROWSER_ACTION_DISCARD) {
    DiscardForm (gCurrentSelection->FormSet, gCurrentSelection->Form, gBrowserSettingScope);
  }
 
  if ((Action & BROWSER_ACTION_DEFAULT) == BROWSER_ACTION_DEFAULT) {
    ExtractDefault (gCurrentSelection->FormSet, gCurrentSelection->Form, DefaultId, gBrowserSettingScope, GetDefaultForAll, NULL, FALSE, FALSE);
    UpdateStatementStatus (gCurrentSelection->FormSet, gCurrentSelection->Form, gBrowserSettingScope);
  }
 
  if ((Action & BROWSER_ACTION_SUBMIT) == BROWSER_ACTION_SUBMIT) {
    SubmitForm (gCurrentSelection->FormSet, gCurrentSelection->Form, gBrowserSettingScope);
  }
 
  if ((Action & BROWSER_ACTION_RESET) == BROWSER_ACTION_RESET) {
    gResetRequiredFormLevel   = TRUE;
    gResetRequiredSystemLevel = TRUE;
  }
 
  if ((Action & BROWSER_ACTION_EXIT) == BROWSER_ACTION_EXIT) {
    //
    // Form Exit without saving, Similar to ESC Key.
    // FormSet Exit without saving, Exit SendForm.
    // System Exit without saving, CallExitHandler and Exit SendForm.
    //
    DiscardForm (gCurrentSelection->FormSet, gCurrentSelection->Form, gBrowserSettingScope);
    if ((gBrowserSettingScope == FormLevel) || (gBrowserSettingScope == FormSetLevel)) {
      FindNextMenu (gCurrentSelection, gBrowserSettingScope);
    } else if (gBrowserSettingScope == SystemLevel) {
      if (ExitHandlerFunction != NULL) {
        ExitHandlerFunction ();
      }
 
      gCurrentSelection->Action = UI_ACTION_EXIT;
    }
  }
 
  return EFI_SUCCESS;
}
 
BOOLEAN
GetFormsetGuidFromHiiHandle (
  IN EFI_HII_HANDLE  HiiHandle,
  IN EFI_GUID        *FormSetGuid
  )
{
  EFI_HII_PACKAGE_LIST_HEADER  *HiiPackageList;
  UINTN                        BufferSize;
  UINT32                       Offset;
  UINT32                       Offset2;
  UINT32                       PackageListLength;
  EFI_HII_PACKAGE_HEADER       PackageHeader;
  UINT8                        *Package;
  UINT8                        *OpCodeData;
  EFI_STATUS                   Status;
  BOOLEAN                      FindGuid;
 
  BufferSize     = 0;
  HiiPackageList = NULL;
  FindGuid       = FALSE;
 
  Status = mHiiDatabase->ExportPackageLists (mHiiDatabase, HiiHandle, &BufferSize, HiiPackageList);
  if (Status == EFI_BUFFER_TOO_SMALL) {
    HiiPackageList = AllocatePool (BufferSize);
    ASSERT (HiiPackageList != NULL);
 
    Status = mHiiDatabase->ExportPackageLists (mHiiDatabase, HiiHandle, &BufferSize, HiiPackageList);
  }
 
  if (EFI_ERROR (Status) || (HiiPackageList == NULL)) {
    return FALSE;
  }
 
  //
  // Get Form package from this HII package List
  //
  Offset  = sizeof (EFI_HII_PACKAGE_LIST_HEADER);
  Offset2 = 0;
  CopyMem (&PackageListLength, &HiiPackageList->PackageLength, sizeof (UINT32));
 
  while (Offset < PackageListLength) {
    Package = ((UINT8 *)HiiPackageList) + Offset;
    CopyMem (&PackageHeader, Package, sizeof (EFI_HII_PACKAGE_HEADER));
    Offset += PackageHeader.Length;
 
    if (PackageHeader.Type == EFI_HII_PACKAGE_FORMS) {
      //
      // Search FormSet in this Form Package
      //
      Offset2 = sizeof (EFI_HII_PACKAGE_HEADER);
      while (Offset2 < PackageHeader.Length) {
        OpCodeData = Package + Offset2;
 
        if (((EFI_IFR_OP_HEADER *)OpCodeData)->OpCode == EFI_IFR_FORM_SET_OP) {
          if (CompareGuid (FormSetGuid, (EFI_GUID *)(OpCodeData + sizeof (EFI_IFR_OP_HEADER)))) {
            FindGuid = TRUE;
            break;
          }
        }
 
        Offset2 += ((EFI_IFR_OP_HEADER *)OpCodeData)->Length;
      }
    }
 
    if (FindGuid) {
      break;
    }
  }
 
  FreePool (HiiPackageList);
 
  return FindGuid;
}
 
EFI_HII_HANDLE
DevicePathToHiiHandle (
  IN EFI_DEVICE_PATH_PROTOCOL  *DevicePath,
  IN EFI_GUID                  *FormsetGuid
  )
{
  EFI_STATUS                Status;
  EFI_DEVICE_PATH_PROTOCOL  *TmpDevicePath;
  UINTN                     Index;
  EFI_HANDLE                Handle;
  EFI_HANDLE                DriverHandle;
  EFI_HII_HANDLE            *HiiHandles;
  EFI_HII_HANDLE            HiiHandle;
 
  ASSERT (DevicePath != NULL);
 
  TmpDevicePath = DevicePath;
  //
  // Locate Device Path Protocol handle buffer
  //
  Status = gBS->LocateDevicePath (
                  &gEfiDevicePathProtocolGuid,
                  &TmpDevicePath,
                  &DriverHandle
                  );
  if (EFI_ERROR (Status) || !IsDevicePathEnd (TmpDevicePath)) {
    return NULL;
  }
 
  //
  // Retrieve all HII Handles from HII database
  //
  HiiHandles = HiiGetHiiHandles (NULL);
  if (HiiHandles == NULL) {
    return NULL;
  }
 
  //
  // Search Hii Handle by Driver Handle
  //
  HiiHandle = NULL;
  for (Index = 0; HiiHandles[Index] != NULL; Index++) {
    Status = mHiiDatabase->GetPackageListHandle (
                             mHiiDatabase,
                             HiiHandles[Index],
                             &Handle
                             );
    if (!EFI_ERROR (Status) && (Handle == DriverHandle)) {
      if (GetFormsetGuidFromHiiHandle (HiiHandles[Index], FormsetGuid)) {
        HiiHandle = HiiHandles[Index];
        break;
      }
 
      if (HiiHandle != NULL) {
        break;
      }
    }
  }
 
  FreePool (HiiHandles);
  return HiiHandle;
}
 
EFI_HII_HANDLE
FormSetGuidToHiiHandle (
  EFI_GUID  *ComparingGuid
  )
{
  EFI_HII_HANDLE  *HiiHandles;
  EFI_HII_HANDLE  HiiHandle;
  UINTN           Index;
 
  ASSERT (ComparingGuid != NULL);
 
  HiiHandle = NULL;
  //
  // Get all the Hii handles
  //
  HiiHandles = HiiGetHiiHandles (NULL);
  ASSERT (HiiHandles != NULL);
 
  //
  // Search for formset of each class type
  //
  for (Index = 0; HiiHandles[Index] != NULL; Index++) {
    if (GetFormsetGuidFromHiiHandle (HiiHandles[Index], ComparingGuid)) {
      HiiHandle = HiiHandles[Index];
      break;
    }
 
    if (HiiHandle != NULL) {
      break;
    }
  }
 
  FreePool (HiiHandles);
 
  return HiiHandle;
}
 
BOOLEAN
ProcessChangedData (
  IN OUT UI_MENU_SELECTION      *Selection,
  IN     BROWSER_SETTING_SCOPE  Scope
  )
{
  BOOLEAN     RetValue;
  EFI_STATUS  Status;
 
  RetValue = TRUE;
  switch (mFormDisplay->ConfirmDataChange ()) {
    case BROWSER_ACTION_DISCARD:
      DiscardForm (Selection->FormSet, Selection->Form, Scope);
      break;
 
    case BROWSER_ACTION_SUBMIT:
      Status = SubmitForm (Selection->FormSet, Selection->Form, Scope);
      if (EFI_ERROR (Status)) {
        RetValue = FALSE;
      }
 
      break;
 
    case BROWSER_ACTION_NONE:
      RetValue = FALSE;
      break;
 
    default:
      //
      // if Invalid value return, process same as BROWSER_ACTION_NONE.
      //
      RetValue = FALSE;
      break;
  }
 
  return RetValue;
}
 
VOID
FindParentFormSet (
  IN OUT   UI_MENU_SELECTION  *Selection
  )
{
  FORM_ENTRY_INFO  *CurrentMenu;
  FORM_ENTRY_INFO  *ParentMenu;
 
  CurrentMenu = Selection->CurrentMenu;
  ParentMenu  = UiFindParentMenu (CurrentMenu, FormSetLevel);
 
  if (ParentMenu != NULL) {
    CopyMem (&Selection->FormSetGuid, &ParentMenu->FormSetGuid, sizeof (EFI_GUID));
    Selection->Handle     = ParentMenu->HiiHandle;
    Selection->FormId     = ParentMenu->FormId;
    Selection->QuestionId = ParentMenu->QuestionId;
  } else {
    Selection->FormId     = CurrentMenu->FormId;
    Selection->QuestionId = CurrentMenu->QuestionId;
  }
 
  Selection->Statement = NULL;
}
 
EFI_STATUS
ProcessGotoOpCode (
  IN OUT   FORM_BROWSER_STATEMENT  *Statement,
  IN OUT   UI_MENU_SELECTION       *Selection
  )
{
  CHAR16                    *StringPtr;
  EFI_DEVICE_PATH_PROTOCOL  *DevicePath;
  FORM_BROWSER_FORM         *RefForm;
  EFI_STATUS                Status;
  EFI_HII_HANDLE            HiiHandle;
 
  Status    = EFI_SUCCESS;
  StringPtr = NULL;
  HiiHandle = NULL;
 
  //
  // Prepare the device path check, get the device path info first.
  //
  if (Statement->HiiValue.Value.ref.DevicePath != 0) {
    StringPtr = GetToken (Statement->HiiValue.Value.ref.DevicePath, Selection->FormSet->HiiHandle);
  }
 
  //
  // Check whether the device path string is a valid string.
  //
  if ((Statement->HiiValue.Value.ref.DevicePath != 0) && (StringPtr != NULL) && (StringPtr[0] != L'\0')) {
    if (Selection->Form->ModalForm) {
      return Status;
    }
 
    //
    // Goto another Hii Package list
    //
    if (mPathFromText != NULL) {
      DevicePath = mPathFromText->ConvertTextToDevicePath (StringPtr);
      if (DevicePath != NULL) {
        HiiHandle = DevicePathToHiiHandle (DevicePath, &Statement->HiiValue.Value.ref.FormSetGuid);
        FreePool (DevicePath);
      }
 
      FreePool (StringPtr);
    } else {
      //
      // Not found the EFI_DEVICE_PATH_FROM_TEXT_PROTOCOL protocol.
      //
      PopupErrorMessage (BROWSER_PROTOCOL_NOT_FOUND, NULL, NULL, NULL);
      FreePool (StringPtr);
      return Status;
    }
 
    if (HiiHandle != Selection->Handle) {
      //
      // Goto another Formset, check for uncommitted data
      //
      if (((gBrowserSettingScope == FormLevel) || (gBrowserSettingScope == FormSetLevel)) &&
          IsNvUpdateRequiredForFormSet (Selection->FormSet))
      {
        if (!ProcessChangedData (Selection, FormSetLevel)) {
          return EFI_SUCCESS;
        }
      }
    }
 
    Selection->Action = UI_ACTION_REFRESH_FORMSET;
    Selection->Handle = HiiHandle;
    if (Selection->Handle == NULL) {
      //
      // If target Hii Handle not found, exit current formset.
      //
      FindParentFormSet (Selection);
      return EFI_SUCCESS;
    }
 
    CopyMem (&Selection->FormSetGuid, &Statement->HiiValue.Value.ref.FormSetGuid, sizeof (EFI_GUID));
    Selection->FormId     = Statement->HiiValue.Value.ref.FormId;
    Selection->QuestionId = Statement->HiiValue.Value.ref.QuestionId;
  } else if (!IsZeroGuid (&Statement->HiiValue.Value.ref.FormSetGuid)) {
    if (Selection->Form->ModalForm) {
      return Status;
    }
 
    if (!CompareGuid (&Statement->HiiValue.Value.ref.FormSetGuid, &Selection->FormSetGuid)) {
      //
      // Goto another Formset, check for uncommitted data
      //
      if (((gBrowserSettingScope == FormLevel) || (gBrowserSettingScope == FormSetLevel)) &&
          IsNvUpdateRequiredForFormSet (Selection->FormSet))
      {
        if (!ProcessChangedData (Selection, FormSetLevel)) {
          return EFI_SUCCESS;
        }
      }
    }
 
    Selection->Action = UI_ACTION_REFRESH_FORMSET;
    Selection->Handle = FormSetGuidToHiiHandle (&Statement->HiiValue.Value.ref.FormSetGuid);
    if (Selection->Handle == NULL) {
      //
      // If target Hii Handle not found, exit current formset.
      //
      FindParentFormSet (Selection);
      return EFI_SUCCESS;
    }
 
    CopyMem (&Selection->FormSetGuid, &Statement->HiiValue.Value.ref.FormSetGuid, sizeof (EFI_GUID));
    Selection->FormId     = Statement->HiiValue.Value.ref.FormId;
    Selection->QuestionId = Statement->HiiValue.Value.ref.QuestionId;
  } else if (Statement->HiiValue.Value.ref.FormId != 0) {
    //
    // Goto another Form, check for uncommitted data
    //
    if (Statement->HiiValue.Value.ref.FormId != Selection->FormId) {
      if (((gBrowserSettingScope == FormLevel) && IsNvUpdateRequiredForForm (Selection->Form))) {
        if (!ProcessChangedData (Selection, FormLevel)) {
          return EFI_SUCCESS;
        }
      }
    }
 
    RefForm = IdToForm (Selection->FormSet, Statement->HiiValue.Value.ref.FormId);
    if ((RefForm != NULL) && (RefForm->SuppressExpression != NULL)) {
      if (EvaluateExpressionList (RefForm->SuppressExpression, TRUE, Selection->FormSet, RefForm) != ExpressFalse) {
        //
        // Form is suppressed.
        //
        PopupErrorMessage (BROWSER_FORM_SUPPRESS, NULL, NULL, NULL);
        return EFI_SUCCESS;
      }
    }
 
    Selection->FormId     = Statement->HiiValue.Value.ref.FormId;
    Selection->QuestionId = Statement->HiiValue.Value.ref.QuestionId;
  } else if (Statement->HiiValue.Value.ref.QuestionId != 0) {
    Selection->QuestionId = Statement->HiiValue.Value.ref.QuestionId;
  }
 
  return Status;
}
 
EFI_STATUS
ProcessQuestionConfig (
  IN  UI_MENU_SELECTION       *Selection,
  IN  FORM_BROWSER_STATEMENT  *Question
  )
{
  EFI_STATUS  Status;
  CHAR16      *ConfigResp;
  CHAR16      *Progress;
 
  if (Question->QuestionConfig == 0) {
    return EFI_SUCCESS;
  }
 
  //
  // Get <ConfigResp>
  //
  ConfigResp = GetToken (Question->QuestionConfig, Selection->FormSet->HiiHandle);
  if (ConfigResp == NULL) {
    return EFI_NOT_FOUND;
  } else if (ConfigResp[0] == L'\0') {
    return EFI_SUCCESS;
  }
 
  //
  // Send config to Configuration Driver
  //
  Status = mHiiConfigRouting->RouteConfig (
                                mHiiConfigRouting,
                                ConfigResp,
                                &Progress
                                );
 
  return Status;
}
 
EFI_STATUS
ProcessUserInput (
  IN USER_INPUT  *UserInput
  )
{
  EFI_STATUS              Status;
  FORM_BROWSER_STATEMENT  *Statement;
 
  Status    = EFI_SUCCESS;
  Statement = NULL;
 
  //
  // When Exit from FormDisplay function, one of the below two cases must be true.
  //
  ASSERT (UserInput->Action != 0 || UserInput->SelectedStatement != NULL);
 
  //
  // Remove the last highligh question id, this id will update when show next form.
  //
  gCurrentSelection->QuestionId = 0;
  if (UserInput->SelectedStatement != NULL) {
    Statement = GetBrowserStatement (UserInput->SelectedStatement);
    ASSERT (Statement != NULL);
 
    //
    // This question is the current user select one,record it and later
    // show it as the highlight question.
    //
    gCurrentSelection->CurrentMenu->QuestionId = Statement->QuestionId;
    //
    // For statement like text, actio, it not has question id.
    // So use FakeQuestionId to save the question.
    //
    if (gCurrentSelection->CurrentMenu->QuestionId == 0) {
      mCurFakeQestId = Statement->FakeQuestionId;
    } else {
      mCurFakeQestId = 0;
    }
  }
 
  //
  // First process the Action field in USER_INPUT.
  //
  if (UserInput->Action != 0) {
    Status                       = ProcessAction (UserInput->Action, UserInput->DefaultId);
    gCurrentSelection->Statement = NULL;
  } else {
    ASSERT (Statement != NULL);
    gCurrentSelection->Statement = Statement;
    switch (Statement->Operand) {
      case EFI_IFR_REF_OP:
        Status = ProcessGotoOpCode (Statement, gCurrentSelection);
        break;
 
      case EFI_IFR_ACTION_OP:
        //
        // Process the Config string <ConfigResp>
        //
        Status = ProcessQuestionConfig (gCurrentSelection, Statement);
        break;
 
      case EFI_IFR_RESET_BUTTON_OP:
        //
        // Reset Question to default value specified by DefaultId
        //
        Status = ExtractDefault (gCurrentSelection->FormSet, NULL, Statement->DefaultId, FormSetLevel, GetDefaultForAll, NULL, FALSE, FALSE);
        UpdateStatementStatus (gCurrentSelection->FormSet, NULL, FormSetLevel);
        break;
 
      default:
        switch (Statement->Operand) {
          case EFI_IFR_STRING_OP:
            DeleteString (Statement->HiiValue.Value.string, gCurrentSelection->FormSet->HiiHandle);
            Statement->HiiValue.Value.string = UserInput->InputValue.Value.string;
            CopyMem (Statement->BufferValue, UserInput->InputValue.Buffer, (UINTN)UserInput->InputValue.BufferLen);
            FreePool (UserInput->InputValue.Buffer);
            break;
 
          case EFI_IFR_PASSWORD_OP:
            if (UserInput->InputValue.Buffer == NULL) {
              //
              // User not input new password, just return.
              //
              break;
            }
 
            DeleteString (Statement->HiiValue.Value.string, gCurrentSelection->FormSet->HiiHandle);
            Statement->HiiValue.Value.string = UserInput->InputValue.Value.string;
            CopyMem (Statement->BufferValue, UserInput->InputValue.Buffer, (UINTN)UserInput->InputValue.BufferLen);
            ZeroMem (UserInput->InputValue.Buffer, (UINTN)UserInput->InputValue.BufferLen);
            FreePool (UserInput->InputValue.Buffer);
            //
            // Two password match, send it to Configuration Driver
            //
            if ((Statement->QuestionFlags & EFI_IFR_FLAG_CALLBACK) != 0) {
              PasswordCheck (NULL, UserInput->SelectedStatement, (CHAR16 *)Statement->BufferValue);
              //
              // Clean the value after saved it.
              //
              ZeroMem (Statement->BufferValue, (UINTN)UserInput->InputValue.BufferLen);
              HiiSetString (gCurrentSelection->FormSet->HiiHandle, Statement->HiiValue.Value.string, (CHAR16 *)Statement->BufferValue, NULL);
            } else {
              SetQuestionValue (gCurrentSelection->FormSet, gCurrentSelection->Form, Statement, GetSetValueWithHiiDriver);
            }
 
            break;
 
          case EFI_IFR_ORDERED_LIST_OP:
            CopyMem (Statement->BufferValue, UserInput->InputValue.Buffer, UserInput->InputValue.BufferLen);
            break;
 
          default:
            CopyMem (&Statement->HiiValue, &UserInput->InputValue, sizeof (EFI_HII_VALUE));
            break;
        }
 
        break;
    }
  }
 
  return Status;
}
 
EFI_STATUS
DisplayForm (
  VOID
  )
{
  EFI_STATUS       Status;
  USER_INPUT       UserInput;
  FORM_ENTRY_INFO  *CurrentMenu;
 
  ZeroMem (&UserInput, sizeof (USER_INPUT));
 
  //
  // Update the menu history data.
  //
  CurrentMenu = UiFindMenuList (gCurrentSelection->Handle, &gCurrentSelection->FormSetGuid, gCurrentSelection->FormId);
  if (CurrentMenu == NULL) {
    //
    // Current menu not found, add it to the menu tree
    //
    CurrentMenu = UiAddMenuList (
                    gCurrentSelection->Handle,
                    &gCurrentSelection->FormSetGuid,
                    gCurrentSelection->FormId,
                    gCurrentSelection->QuestionId
                    );
    ASSERT (CurrentMenu != NULL);
  }
 
  //
  // Back up the form view history data for this form.
  //
  UiCopyMenuList (&gCurrentSelection->Form->FormViewListHead, &mPrivateData.FormBrowserEx2.FormViewHistoryHead);
 
  gCurrentSelection->CurrentMenu = CurrentMenu;
 
  if (gCurrentSelection->QuestionId == 0) {
    //
    // Highlight not specified, fetch it from cached menu
    //
    gCurrentSelection->QuestionId = CurrentMenu->QuestionId;
  }
 
  Status = EvaluateFormExpressions (gCurrentSelection->FormSet, gCurrentSelection->Form);
  if (EFI_ERROR (Status)) {
    return Status;
  }
 
  UpdateDisplayFormData ();
 
  ASSERT (gDisplayFormData.BrowserStatus == BROWSER_SUCCESS);
  Status = mFormDisplay->FormDisplay (&gDisplayFormData, &UserInput);
  if (EFI_ERROR (Status)) {
    FreeDisplayFormData ();
    return Status;
  }
 
  CheckConfigAccess (gCurrentSelection->FormSet);
 
  Status = ProcessUserInput (&UserInput);
  FreeDisplayFormData ();
  return Status;
}
 
EFI_STATUS
EFIAPI
FormUpdateNotify (
  IN UINT8                         PackageType,
  IN CONST EFI_GUID                *PackageGuid,
  IN CONST EFI_HII_PACKAGE_HEADER  *Package,
  IN EFI_HII_HANDLE                Handle,
  IN EFI_HII_DATABASE_NOTIFY_TYPE  NotifyType
  )
{
  mHiiPackageListUpdated = TRUE;
 
  return EFI_SUCCESS;
}
 
BOOLEAN
IsNvUpdateRequiredForFormSet (
  IN FORM_BROWSER_FORMSET  *FormSet
  )
{
  LIST_ENTRY         *Link;
  FORM_BROWSER_FORM  *Form;
  BOOLEAN            RetVal;
 
  //
  // Not finished question initialization, return FALSE.
  //
  if (!FormSet->QuestionInited) {
    return FALSE;
  }
 
  RetVal = FALSE;
 
  Link = GetFirstNode (&FormSet->FormListHead);
  while (!IsNull (&FormSet->FormListHead, Link)) {
    Form = FORM_BROWSER_FORM_FROM_LINK (Link);
 
    RetVal = IsNvUpdateRequiredForForm (Form);
    if (RetVal) {
      break;
    }
 
    Link = GetNextNode (&FormSet->FormListHead, Link);
  }
 
  return RetVal;
}
 
BOOLEAN
IsNvUpdateRequiredForForm (
  IN FORM_BROWSER_FORM  *Form
  )
{
  LIST_ENTRY              *Link;
  FORM_BROWSER_STATEMENT  *Statement;
 
  Link = GetFirstNode (&Form->StatementListHead);
  while (!IsNull (&Form->StatementListHead, Link)) {
    Statement = FORM_BROWSER_STATEMENT_FROM_LINK (Link);
 
    if (Statement->ValueChanged) {
      return TRUE;
    }
 
    Link = GetNextNode (&Form->StatementListHead, Link);
  }
 
  return FALSE;
}
 
BOOLEAN
FindNextMenu (
  IN OUT UI_MENU_SELECTION      *Selection,
  IN     BROWSER_SETTING_SCOPE  SettingLevel
  )
{
  FORM_ENTRY_INFO        *CurrentMenu;
  FORM_ENTRY_INFO        *ParentMenu;
  BROWSER_SETTING_SCOPE  Scope;
 
  CurrentMenu = Selection->CurrentMenu;
  Scope       = FormSetLevel;
 
  ParentMenu = UiFindParentMenu (CurrentMenu, SettingLevel);
  while (ParentMenu != NULL && !ValidateHiiHandle (ParentMenu->HiiHandle)) {
    ParentMenu = UiFindParentMenu (ParentMenu, SettingLevel);
  }
 
  if (ParentMenu != NULL) {
    if (CompareGuid (&CurrentMenu->FormSetGuid, &ParentMenu->FormSetGuid)) {
      Scope = FormLevel;
    } else {
      Scope = FormSetLevel;
    }
  }
 
  //
  // Form Level Check whether the data is changed.
  //
  if (((gBrowserSettingScope == FormLevel) && IsNvUpdateRequiredForForm (Selection->Form)) ||
      ((gBrowserSettingScope == FormSetLevel) && IsNvUpdateRequiredForFormSet (Selection->FormSet) && (Scope == FormSetLevel)))
  {
    if (!ProcessChangedData (Selection, gBrowserSettingScope)) {
      return FALSE;
    }
  }
 
  if (ParentMenu != NULL) {
    //
    // ParentMenu is found. Then, go to it.
    //
    if (Scope == FormLevel) {
      Selection->Action = UI_ACTION_REFRESH_FORM;
    } else {
      Selection->Action = UI_ACTION_REFRESH_FORMSET;
      CopyMem (&Selection->FormSetGuid, &ParentMenu->FormSetGuid, sizeof (EFI_GUID));
      Selection->Handle = ParentMenu->HiiHandle;
    }
 
    Selection->Statement = NULL;
 
    Selection->FormId     = ParentMenu->FormId;
    Selection->QuestionId = ParentMenu->QuestionId;
 
    //
    // Clear highlight record for this menu
    //
    CurrentMenu->QuestionId = 0;
    return FALSE;
  }
 
  //
  // Current in root page, exit the SendForm
  //
  Selection->Action = UI_ACTION_EXIT;
 
  return TRUE;
}
 
BOOLEAN
ReconnectController (
  IN EFI_HANDLE  DriverHandle
  )
{
  EFI_STATUS  Status;
 
  Status = gBS->DisconnectController (DriverHandle, NULL, NULL);
  if (!EFI_ERROR (Status)) {
    Status = gBS->ConnectController (DriverHandle, NULL, NULL, TRUE);
  }
 
  return Status == EFI_SUCCESS;
}
 
EFI_STATUS
ProcessCallBackFunction (
  IN OUT UI_MENU_SELECTION       *Selection,
  IN     FORM_BROWSER_FORMSET    *FormSet,
  IN     FORM_BROWSER_FORM       *Form,
  IN     FORM_BROWSER_STATEMENT  *Question,
  IN     EFI_BROWSER_ACTION      Action,
  IN     BOOLEAN                 SkipSaveOrDiscard
  )
{
  EFI_STATUS                      Status;
  EFI_STATUS                      InternalStatus;
  EFI_BROWSER_ACTION_REQUEST      ActionRequest;
  EFI_HII_CONFIG_ACCESS_PROTOCOL  *ConfigAccess;
  EFI_HII_VALUE                   *HiiValue;
  EFI_IFR_TYPE_VALUE              *TypeValue;
  FORM_BROWSER_STATEMENT          *Statement;
  BOOLEAN                         SubmitFormIsRequired;
  BOOLEAN                         DiscardFormIsRequired;
  BOOLEAN                         NeedExit;
  LIST_ENTRY                      *Link;
  BROWSER_SETTING_SCOPE           SettingLevel;
  EFI_IFR_TYPE_VALUE              BackUpValue;
  UINT8                           *BackUpBuffer;
  CHAR16                          *NewString;
 
  ConfigAccess          = FormSet->ConfigAccess;
  SubmitFormIsRequired  = FALSE;
  SettingLevel          = FormSetLevel;
  DiscardFormIsRequired = FALSE;
  NeedExit              = FALSE;
  Status                = EFI_SUCCESS;
  ActionRequest         = EFI_BROWSER_ACTION_REQUEST_NONE;
  BackUpBuffer          = NULL;
 
  if (ConfigAccess == NULL) {
    return EFI_SUCCESS;
  }
 
  Link = GetFirstNode (&Form->StatementListHead);
  while (!IsNull (&Form->StatementListHead, Link)) {
    Statement = FORM_BROWSER_STATEMENT_FROM_LINK (Link);
    Link      = GetNextNode (&Form->StatementListHead, Link);
 
    //
    // if Question != NULL, only process the question. Else, process all question in this form.
    //
    if ((Question != NULL) && (Statement != Question)) {
      continue;
    }
 
    if ((Statement->QuestionFlags & EFI_IFR_FLAG_CALLBACK) != EFI_IFR_FLAG_CALLBACK) {
      continue;
    }
 
    //
    // Check whether Statement is disabled.
    //
    if (Statement->Expression != NULL) {
      if (EvaluateExpressionList (Statement->Expression, TRUE, FormSet, Form) == ExpressDisable) {
        continue;
      }
    }
 
    HiiValue  = &Statement->HiiValue;
    TypeValue = &HiiValue->Value;
    if (HiiValue->Type == EFI_IFR_TYPE_BUFFER) {
      //
      // For OrderedList, passing in the value buffer to Callback()
      //
      TypeValue = (EFI_IFR_TYPE_VALUE *)Statement->BufferValue;
    }
 
    //
    // If EFI_BROWSER_ACTION_CHANGING type, back up the new question value.
    //
    if (Action == EFI_BROWSER_ACTION_CHANGING) {
      if (HiiValue->Type == EFI_IFR_TYPE_BUFFER) {
        BackUpBuffer = AllocateCopyPool (Statement->StorageWidth, Statement->BufferValue);
        ASSERT (BackUpBuffer != NULL);
      } else {
        CopyMem (&BackUpValue, &HiiValue->Value, sizeof (EFI_IFR_TYPE_VALUE));
      }
    }
 
    ActionRequest = EFI_BROWSER_ACTION_REQUEST_NONE;
    Status        = ConfigAccess->Callback (
                                    ConfigAccess,
                                    Action,
                                    Statement->QuestionId,
                                    HiiValue->Type,
                                    TypeValue,
                                    &ActionRequest
                                    );
    if (!EFI_ERROR (Status)) {
      //
      // Need to sync the value between Statement->HiiValue->Value and Statement->BufferValue
      //
      if (HiiValue->Type == EFI_IFR_TYPE_STRING) {
        NewString = GetToken (Statement->HiiValue.Value.string, FormSet->HiiHandle);
        ASSERT (NewString != NULL);
 
        ASSERT (StrLen (NewString) * sizeof (CHAR16) <= Statement->StorageWidth);
        if (StrLen (NewString) * sizeof (CHAR16) <= Statement->StorageWidth) {
          ZeroMem (Statement->BufferValue, Statement->StorageWidth);
          CopyMem (Statement->BufferValue, NewString, StrSize (NewString));
        } else {
          CopyMem (Statement->BufferValue, NewString, Statement->StorageWidth);
        }
 
        FreePool (NewString);
      }
 
      //
      // Only for EFI_BROWSER_ACTION_CHANGED need to handle this ActionRequest.
      //
      switch (Action) {
        case EFI_BROWSER_ACTION_CHANGED:
          switch (ActionRequest) {
            case EFI_BROWSER_ACTION_REQUEST_RESET:
              DiscardFormIsRequired     = TRUE;
              gResetRequiredFormLevel   = TRUE;
              gResetRequiredSystemLevel = TRUE;
              NeedExit                  = TRUE;
              break;
 
            case EFI_BROWSER_ACTION_REQUEST_SUBMIT:
              SubmitFormIsRequired = TRUE;
              NeedExit             = TRUE;
              break;
 
            case EFI_BROWSER_ACTION_REQUEST_EXIT:
              DiscardFormIsRequired = TRUE;
              NeedExit              = TRUE;
              break;
 
            case EFI_BROWSER_ACTION_REQUEST_FORM_SUBMIT_EXIT:
              SubmitFormIsRequired = TRUE;
              SettingLevel         = FormLevel;
              NeedExit             = TRUE;
              break;
 
            case EFI_BROWSER_ACTION_REQUEST_FORM_DISCARD_EXIT:
              DiscardFormIsRequired = TRUE;
              SettingLevel          = FormLevel;
              NeedExit              = TRUE;
              break;
 
            case EFI_BROWSER_ACTION_REQUEST_FORM_APPLY:
              SubmitFormIsRequired = TRUE;
              SettingLevel         = FormLevel;
              break;
 
            case EFI_BROWSER_ACTION_REQUEST_FORM_DISCARD:
              DiscardFormIsRequired = TRUE;
              SettingLevel          = FormLevel;
              break;
 
            case EFI_BROWSER_ACTION_REQUEST_RECONNECT:
              gCallbackReconnect = TRUE;
              break;
 
            case EFI_BROWSER_ACTION_REQUEST_QUESTION_APPLY:
              Status = SetQuestionValue (
                         gCurrentSelection->FormSet,
                         gCurrentSelection->Form,
                         Statement,
                         GetSetValueWithHiiDriver
                         );
              break;
 
            default:
              break;
          }
 
          break;
 
        case EFI_BROWSER_ACTION_CHANGING:
          //
          // Do the question validation.
          //
          Status = ValueChangedValidation (gCurrentSelection->FormSet, gCurrentSelection->Form, Statement);
          if (!EFI_ERROR (Status)) {
            //
            // check whether the question value  changed compared with edit buffer before updating edit buffer
            // if changed, set the ValueChanged flag to TRUE,in order to trig the CHANGED callback function
            //
            IsQuestionValueChanged (gCurrentSelection->FormSet, gCurrentSelection->Form, Statement, GetSetValueWithEditBuffer);
            //
            // According the spec, return value from call back of "changing" and
            // "retrieve" should update to the question's temp buffer.
            //
            SetQuestionValue (FormSet, Form, Statement, GetSetValueWithEditBuffer);
          }
 
          break;
 
        case EFI_BROWSER_ACTION_RETRIEVE:
          //
          // According the spec, return value from call back of "changing" and
          // "retrieve" should update to the question's temp buffer.
          //
          SetQuestionValue (FormSet, Form, Statement, GetSetValueWithEditBuffer);
          break;
 
        default:
          break;
      }
    } else {
      //
      // If the callback returns EFI_UNSUPPORTED for EFI_BROWSER_ACTION_CHANGING,
      // then the browser will use the value passed to Callback() and ignore the
      // value returned by Callback().
      //
      if ((Action  == EFI_BROWSER_ACTION_CHANGING) && (Status == EFI_UNSUPPORTED)) {
        if (HiiValue->Type == EFI_IFR_TYPE_BUFFER) {
          CopyMem (Statement->BufferValue, BackUpBuffer, Statement->StorageWidth);
        } else {
          CopyMem (&HiiValue->Value, &BackUpValue, sizeof (EFI_IFR_TYPE_VALUE));
        }
 
        //
        // Do the question validation.
        //
        InternalStatus = ValueChangedValidation (gCurrentSelection->FormSet, gCurrentSelection->Form, Statement);
        if (!EFI_ERROR (InternalStatus)) {
          //
          // check whether the question value  changed compared with edit buffer before updating edit buffer
          // if changed, set the ValueChanged flag to TRUE,in order to trig the CHANGED callback function
          //
          IsQuestionValueChanged (gCurrentSelection->FormSet, gCurrentSelection->Form, Statement, GetSetValueWithEditBuffer);
          SetQuestionValue (FormSet, Form, Statement, GetSetValueWithEditBuffer);
        }
      }
 
      //
      // According the spec, return fail from call back of "changing" and
      // "retrieve", should restore the question's value.
      //
      if ((Action == EFI_BROWSER_ACTION_CHANGING) && (Status != EFI_UNSUPPORTED)) {
        if (Statement->Storage != NULL) {
          GetQuestionValue (FormSet, Form, Statement, GetSetValueWithEditBuffer);
        } else if ((Statement->QuestionFlags & EFI_IFR_FLAG_CALLBACK) != 0) {
          ProcessCallBackFunction (Selection, FormSet, Form, Question, EFI_BROWSER_ACTION_RETRIEVE, FALSE);
        }
      }
 
      if (Action == EFI_BROWSER_ACTION_RETRIEVE) {
        GetQuestionValue (FormSet, Form, Statement, GetSetValueWithEditBuffer);
      }
 
      if (Status == EFI_UNSUPPORTED) {
        //
        // If return EFI_UNSUPPORTED, also consider Hii driver suceess deal with it.
        //
        Status = EFI_SUCCESS;
      }
    }
 
    if (BackUpBuffer != NULL) {
      FreePool (BackUpBuffer);
    }
 
    //
    // If Question != NULL, means just process one question
    // and if code reach here means this question has finished
    // processing, so just break.
    //
    if (Question != NULL) {
      break;
    }
  }
 
  if (gCallbackReconnect && (EFI_BROWSER_ACTION_CHANGED == Action)) {
    //
    // Confirm changes with user first.
    //
    if (IsNvUpdateRequiredForFormSet (FormSet)) {
      if (BROWSER_ACTION_DISCARD == PopupErrorMessage (BROWSER_RECONNECT_SAVE_CHANGES, NULL, NULL, NULL)) {
        gCallbackReconnect    = FALSE;
        DiscardFormIsRequired = TRUE;
      } else {
        SubmitFormIsRequired = TRUE;
      }
    } else {
      PopupErrorMessage (BROWSER_RECONNECT_REQUIRED, NULL, NULL, NULL);
    }
 
    //
    // Exit current formset before do the reconnect.
    //
    NeedExit     = TRUE;
    SettingLevel = FormSetLevel;
  }
 
  if (SubmitFormIsRequired && !SkipSaveOrDiscard) {
    SubmitForm (FormSet, Form, SettingLevel);
  }
 
  if (DiscardFormIsRequired && !SkipSaveOrDiscard) {
    DiscardForm (FormSet, Form, SettingLevel);
  }
 
  if (NeedExit) {
    FindNextMenu (Selection, SettingLevel);
  }
 
  return Status;
}
 
EFI_STATUS
ProcessRetrieveForQuestion (
  IN     EFI_HII_CONFIG_ACCESS_PROTOCOL  *ConfigAccess,
  IN     FORM_BROWSER_STATEMENT          *Statement,
  IN     FORM_BROWSER_FORMSET            *FormSet
  )
{
  EFI_STATUS                  Status;
  EFI_BROWSER_ACTION_REQUEST  ActionRequest;
  EFI_HII_VALUE               *HiiValue;
  EFI_IFR_TYPE_VALUE          *TypeValue;
  CHAR16                      *NewString;
 
  Status        = EFI_SUCCESS;
  ActionRequest = EFI_BROWSER_ACTION_REQUEST_NONE;
 
  if (((Statement->QuestionFlags & EFI_IFR_FLAG_CALLBACK) != EFI_IFR_FLAG_CALLBACK) || (ConfigAccess == NULL)) {
    return EFI_UNSUPPORTED;
  }
 
  HiiValue  = &Statement->HiiValue;
  TypeValue = &HiiValue->Value;
  if (HiiValue->Type == EFI_IFR_TYPE_BUFFER) {
    //
    // For OrderedList, passing in the value buffer to Callback()
    //
    TypeValue = (EFI_IFR_TYPE_VALUE *)Statement->BufferValue;
  }
 
  ActionRequest = EFI_BROWSER_ACTION_REQUEST_NONE;
  Status        = ConfigAccess->Callback (
                                  ConfigAccess,
                                  EFI_BROWSER_ACTION_RETRIEVE,
                                  Statement->QuestionId,
                                  HiiValue->Type,
                                  TypeValue,
                                  &ActionRequest
                                  );
  if (!EFI_ERROR (Status) && (HiiValue->Type == EFI_IFR_TYPE_STRING)) {
    NewString = GetToken (Statement->HiiValue.Value.string, FormSet->HiiHandle);
    ASSERT (NewString != NULL);
 
    ASSERT (StrLen (NewString) * sizeof (CHAR16) <= Statement->StorageWidth);
    if (StrLen (NewString) * sizeof (CHAR16) <= Statement->StorageWidth) {
      ZeroMem (Statement->BufferValue, Statement->StorageWidth);
      CopyMem (Statement->BufferValue, NewString, StrSize (NewString));
    } else {
      CopyMem (Statement->BufferValue, NewString, Statement->StorageWidth);
    }
 
    FreePool (NewString);
  }
 
  return Status;
}
 
EFI_STATUS
SetupBrowser (
  IN OUT UI_MENU_SELECTION  *Selection
  )
{
  EFI_STATUS                      Status;
  LIST_ENTRY                      *Link;
  EFI_HANDLE                      NotifyHandle;
  FORM_BROWSER_STATEMENT          *Statement;
  EFI_HII_CONFIG_ACCESS_PROTOCOL  *ConfigAccess;
 
  ConfigAccess = Selection->FormSet->ConfigAccess;
 
  //
  // Register notify for Form package update
  //
  Status = mHiiDatabase->RegisterPackageNotify (
                           mHiiDatabase,
                           EFI_HII_PACKAGE_FORMS,
                           NULL,
                           FormUpdateNotify,
                           EFI_HII_DATABASE_NOTIFY_REMOVE_PACK,
                           &NotifyHandle
                           );
  if (EFI_ERROR (Status)) {
    return Status;
  }
 
  //
  // Initialize current settings of Questions in this FormSet
  //
  InitializeCurrentSetting (Selection->FormSet);
 
  //
  // Initilize Action field.
  //
  Selection->Action = UI_ACTION_REFRESH_FORM;
 
  //
  // Clean the mCurFakeQestId value is formset refreshed.
  //
  mCurFakeQestId = 0;
 
  do {
    //
    // Reset Status to prevent the next break from returning incorrect error status.
    //
    Status = EFI_SUCCESS;
 
    //
    // IFR is updated, force to reparse the IFR binary
    // This check is shared by EFI_BROWSER_ACTION_FORM_CLOSE and
    // EFI_BROWSER_ACTION_RETRIEVE, so code place here.
    //
    if (mHiiPackageListUpdated) {
      Selection->Action      = UI_ACTION_REFRESH_FORMSET;
      mHiiPackageListUpdated = FALSE;
      break;
    }
 
    //
    // Initialize Selection->Form
    //
    if (Selection->FormId == 0) {
      //
      // Zero FormId indicates display the first Form in a FormSet
      //
      Link = GetFirstNode (&Selection->FormSet->FormListHead);
 
      Selection->Form   = FORM_BROWSER_FORM_FROM_LINK (Link);
      Selection->FormId = Selection->Form->FormId;
    } else {
      Selection->Form = IdToForm (Selection->FormSet, Selection->FormId);
    }
 
    if (Selection->Form == NULL) {
      //
      // No Form to display
      //
      Status = EFI_NOT_FOUND;
      goto Done;
    }
 
    //
    // Check Form is suppressed.
    //
    if (Selection->Form->SuppressExpression != NULL) {
      if (EvaluateExpressionList (Selection->Form->SuppressExpression, TRUE, Selection->FormSet, Selection->Form) == ExpressSuppress) {
        //
        // Form is suppressed.
        //
        PopupErrorMessage (BROWSER_FORM_SUPPRESS, NULL, NULL, NULL);
        Status = EFI_NOT_FOUND;
        goto Done;
      }
    }
 
    //
    // Before display new form, invoke ConfigAccess.Callback() with EFI_BROWSER_ACTION_FORM_OPEN
    // for each question with callback flag.
    // New form may be the first form, or the different form after another form close.
    //
    if (((Selection->Handle != mCurrentHiiHandle) ||
         (!CompareGuid (&Selection->FormSetGuid, &mCurrentFormSetGuid)) ||
         (Selection->FormId != mCurrentFormId)))
    {
      //
      // Update Retrieve flag.
      //
      mFinishRetrieveCall = FALSE;
 
      //
      // Keep current form information
      //
      mCurrentHiiHandle = Selection->Handle;
      CopyGuid (&mCurrentFormSetGuid, &Selection->FormSetGuid);
      mCurrentFormId = Selection->FormId;
 
      if (ConfigAccess != NULL) {
        Status = ProcessCallBackFunction (Selection, Selection->FormSet, Selection->Form, NULL, EFI_BROWSER_ACTION_FORM_OPEN, FALSE);
        if (EFI_ERROR (Status)) {
          goto Done;
        }
 
        //
        // IFR is updated during callback of EFI_BROWSER_ACTION_FORM_OPEN, force to reparse the IFR binary
        //
        if (mHiiPackageListUpdated) {
          Selection->Action      = UI_ACTION_REFRESH_FORMSET;
          mHiiPackageListUpdated = FALSE;
          break;
        }
      }
    }
 
    //
    // Load Questions' Value for display
    //
    Status = LoadFormSetConfig (Selection, Selection->FormSet);
    if (EFI_ERROR (Status)) {
      goto Done;
    }
 
    if (!mFinishRetrieveCall) {
      //
      // Finish call RETRIEVE callback for this form.
      //
      mFinishRetrieveCall = TRUE;
 
      if (ConfigAccess != NULL) {
        Status = ProcessCallBackFunction (Selection, Selection->FormSet, Selection->Form, NULL, EFI_BROWSER_ACTION_RETRIEVE, FALSE);
        if (EFI_ERROR (Status)) {
          goto Done;
        }
 
        //
        // IFR is updated during callback of open form, force to reparse the IFR binary
        //
        if (mHiiPackageListUpdated) {
          Selection->Action      = UI_ACTION_REFRESH_FORMSET;
          mHiiPackageListUpdated = FALSE;
          break;
        }
      }
    }
 
    //
    // Display form
    //
    Status = DisplayForm ();
    if (EFI_ERROR (Status)) {
      goto Done;
    }
 
    //
    // Check Selected Statement (if press ESC, Selection->Statement will be NULL)
    //
    Statement = Selection->Statement;
    if (Statement != NULL) {
      if ((ConfigAccess != NULL) &&
          ((Statement->QuestionFlags & EFI_IFR_FLAG_CALLBACK) == EFI_IFR_FLAG_CALLBACK) &&
          (Statement->Operand != EFI_IFR_PASSWORD_OP))
      {
        Status = ProcessCallBackFunction (Selection, Selection->FormSet, Selection->Form, Statement, EFI_BROWSER_ACTION_CHANGING, FALSE);
        if (Statement->Operand == EFI_IFR_REF_OP) {
          //
          // Process dynamic update ref opcode.
          //
          if (!EFI_ERROR (Status)) {
            Status = ProcessGotoOpCode (Statement, Selection);
          }
 
          //
          // Callback return error status or status return from process goto opcode.
          //
          if (EFI_ERROR (Status)) {
            //
            // Cross reference will not be taken, restore all essential field
            //
            Selection->Handle = mCurrentHiiHandle;
            CopyMem (&Selection->FormSetGuid, &mCurrentFormSetGuid, sizeof (EFI_GUID));
            Selection->FormId     = mCurrentFormId;
            Selection->QuestionId = 0;
            Selection->Action     = UI_ACTION_REFRESH_FORM;
          }
        }
 
        if (!EFI_ERROR (Status) &&
            (Statement->Operand != EFI_IFR_REF_OP) &&
            ((Statement->Storage == NULL) || ((Statement->Storage != NULL) && Statement->ValueChanged)))
        {
          //
          // Only question value has been changed, browser will trig CHANGED callback.
          //
          ProcessCallBackFunction (Selection, Selection->FormSet, Selection->Form, Statement, EFI_BROWSER_ACTION_CHANGED, FALSE);
          //
          // check whether the question value changed compared with buffer value
          // if doesn't change ,set the ValueChanged flag to FALSE ,in order not to display the "configuration changed "information on the screen
          //
          IsQuestionValueChanged (gCurrentSelection->FormSet, gCurrentSelection->Form, Statement, GetSetValueWithBuffer);
        }
      } else {
        //
        // Do the question validation.
        //
        Status = ValueChangedValidation (gCurrentSelection->FormSet, gCurrentSelection->Form, Statement);
        if (!EFI_ERROR (Status) && (Statement->Operand != EFI_IFR_PASSWORD_OP)) {
          SetQuestionValue (gCurrentSelection->FormSet, gCurrentSelection->Form, Statement, GetSetValueWithEditBuffer);
          //
          // Verify whether question value has checked, update the ValueChanged flag in Question.
          //
          IsQuestionValueChanged (gCurrentSelection->FormSet, gCurrentSelection->Form, Statement, GetSetValueWithBuffer);
        }
      }
 
      //
      // If question has EFI_IFR_FLAG_RESET_REQUIRED/EFI_IFR_FLAG_RECONNECT_REQUIRED flag and without storage
      // and process question success till here, trig the gResetFlag/gFlagReconnect.
      //
      if ((Status == EFI_SUCCESS) &&
          (Statement->Storage == NULL))
      {
        if ((Statement->QuestionFlags & EFI_IFR_FLAG_RESET_REQUIRED) != 0) {
          gResetRequiredFormLevel   = TRUE;
          gResetRequiredSystemLevel = TRUE;
        }
 
        if ((Statement->QuestionFlags & EFI_IFR_FLAG_RECONNECT_REQUIRED) != 0) {
          gFlagReconnect = TRUE;
        }
      }
    }
 
    //
    // Check whether Exit flag is TRUE.
    //
    if (gExitRequired) {
      switch (gBrowserSettingScope) {
        case SystemLevel:
          Selection->Action = UI_ACTION_EXIT;
          break;
 
        case FormSetLevel:
        case FormLevel:
          FindNextMenu (Selection, gBrowserSettingScope);
          break;
 
        default:
          break;
      }
 
      gExitRequired = FALSE;
    }
 
    //
    // Before exit the form, invoke ConfigAccess.Callback() with EFI_BROWSER_ACTION_FORM_CLOSE
    // for each question with callback flag.
    //
    if ((ConfigAccess != NULL) &&
        ((Selection->Action == UI_ACTION_EXIT) ||
         (Selection->Handle != mCurrentHiiHandle) ||
         (!CompareGuid (&Selection->FormSetGuid, &mCurrentFormSetGuid)) ||
         (Selection->FormId != mCurrentFormId)))
    {
      Status = ProcessCallBackFunction (Selection, Selection->FormSet, Selection->Form, NULL, EFI_BROWSER_ACTION_FORM_CLOSE, FALSE);
      if (EFI_ERROR (Status)) {
        goto Done;
      }
    }
  } while (Selection->Action == UI_ACTION_REFRESH_FORM);
 
Done:
  //
  // Reset current form information to the initial setting when error happens or form exit.
  //
  if (EFI_ERROR (Status) || (Selection->Action == UI_ACTION_EXIT)) {
    mCurrentHiiHandle = NULL;
    CopyGuid (&mCurrentFormSetGuid, &gZeroGuid);
    mCurrentFormId = 0;
  }
 
  //
  // Unregister notify for Form package update
  //
  mHiiDatabase->UnregisterPackageNotify (
                  mHiiDatabase,
                  NotifyHandle
                  );
  return Status;
}