/** @file

  This file contains the keyboard processing code to the HII database.

Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution.  The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php

THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/


#include "HiiDatabase.h"
#include "HiiHandle.h"
#include <Library/DebugLib.h>

CONST EFI_GUID  gZeroGuid = {0, 0, 0, {0, 0, 0, 0, 0, 0, 0, 0}};
CONST CHAR16 FrameworkReservedVarstoreName[] = FRAMEWORK_RESERVED_VARSTORE_NAME;

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

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

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

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

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

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

  *HandleBuffer = AllocateZeroPool (*HandleBufferLength);
  
  if (*HandleBuffer == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }
  
  return mHiiDatabase->ListPackageLists (
                         mHiiDatabase,
                         PackageType,
                         PackageGuid,
                         HandleBufferLength,
                         *HandleBuffer
                         );
  
}

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

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

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

  @retval EFI_SUCCESS            Package exported.

  @retval EFI_OUT_OF_RESOURCES   Not enought memory to complete the operations.

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

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

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

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

  return Status;
}

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

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

  @param  Handle              Hii handle
  @param  Guid                Package list GUID

  @retval EFI_SUCCESS            Successfully extract GUID from Hii database.

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

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

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

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

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

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

  FreePool (HiiPackageList);

  return EFI_SUCCESS;
}

/**
  Find the corressponding UEFI HII Handle from a Framework HII Handle given.

  @param Private      The HII Thunk Module Private context.
  @param FwHiiHandle  The Framemwork HII Handle.

  @return NULL        If Framework HII Handle is invalid.
  @return The corresponding UEFI HII Handle.
**/
EFI_HII_HANDLE
FwHiiHandleToUefiHiiHandle (
  IN CONST HII_THUNK_PRIVATE_DATA      *Private,
  IN FRAMEWORK_EFI_HII_HANDLE          FwHiiHandle
  )
{
  HII_THUNK_CONTEXT            *ThunkContext;

  ASSERT (FwHiiHandle != (FRAMEWORK_EFI_HII_HANDLE) 0);
  ASSERT (Private != NULL);

  ThunkContext = FwHiiHandleToThunkContext (Private, FwHiiHandle);

  if (ThunkContext != NULL) {
    return ThunkContext->UefiHiiHandle;
  }
  
  return (EFI_HII_HANDLE) NULL;
}


/**
  Find the corressponding HII Thunk Context from a Framework HII Handle given.

  @param Private      The HII Thunk Module Private context.
  @param FwHiiHandle  The Framemwork HII Handle.

  @return NULL        If Framework HII Handle is invalid.
  @return The corresponding HII Thunk Context.
**/
HII_THUNK_CONTEXT *
FwHiiHandleToThunkContext (
  IN CONST HII_THUNK_PRIVATE_DATA      *Private,
  IN FRAMEWORK_EFI_HII_HANDLE          FwHiiHandle
  )
{
  LIST_ENTRY                 *Link;
  HII_THUNK_CONTEXT           *ThunkContext;


  Link = GetFirstNode (&Private->ThunkContextListHead);

  while (!IsNull (&Private->ThunkContextListHead, Link)) {
    ThunkContext = HII_THUNK_CONTEXT_FROM_LINK (Link);

    if (FwHiiHandle == ThunkContext->FwHiiHandle) {
      return ThunkContext;
    }

    Link = GetNextNode (&Private->ThunkContextListHead, Link);
  }

  return NULL;
}

/**
  Find the corressponding HII Thunk Context from a UEFI HII Handle given.

  @param Private        The HII Thunk Module Private context.
  @param UefiHiiHandle  The UEFI HII Handle.

  @return NULL        If UEFI HII Handle is invalid.
  @return The corresponding HII Thunk Context.
**/
HII_THUNK_CONTEXT *
UefiHiiHandleToThunkContext (
  IN CONST HII_THUNK_PRIVATE_DATA     *Private,
  IN EFI_HII_HANDLE                   UefiHiiHandle
  )
{
  LIST_ENTRY                 *Link;
  HII_THUNK_CONTEXT           *ThunkContext;

  Link = GetFirstNode (&Private->ThunkContextListHead);

  while (!IsNull (&Private->ThunkContextListHead, Link)) {
    ThunkContext = HII_THUNK_CONTEXT_FROM_LINK (Link);

    if (UefiHiiHandle == ThunkContext->UefiHiiHandle) {
      return ThunkContext;
    }
    Link = GetNextNode (&Private->ThunkContextListHead, Link);
  }

  return NULL;
}

/**
  Find the corressponding HII Thunk Context from a Tag GUID.

  @param Private      The HII Thunk Module Private context.
  @param Guid         The Tag GUID.

  @return NULL        No HII Thunk Context matched the Tag GUID.
  @return The corresponding HII Thunk Context.
**/
HII_THUNK_CONTEXT *
TagGuidToIfrPackThunkContext (
  IN CONST HII_THUNK_PRIVATE_DATA *Private,
  IN CONST EFI_GUID                   *Guid
  )
{
  LIST_ENTRY                 *Link;
  HII_THUNK_CONTEXT           *ThunkContext;

  Link = GetFirstNode (&Private->ThunkContextListHead);

  while (!IsNull (&Private->ThunkContextListHead, Link)) {
    ThunkContext = HII_THUNK_CONTEXT_FROM_LINK (Link);

    if (CompareGuid (Guid, &ThunkContext->TagGuid) && (ThunkContext->IfrPackageCount != 0)) {
      return ThunkContext;
    }

    Link = GetNextNode (&Private->ThunkContextListHead, Link);
  }

  return NULL;
  
}

/**
  Clean up the HII Thunk Context for a UEFI HII Handle.

  @param Private        The HII Thunk Module Private context.
  @param UefiHiiHandle  The UEFI HII Handle.

**/
VOID
DestroyThunkContextForUefiHiiHandle (
  IN HII_THUNK_PRIVATE_DATA     *Private,
  IN EFI_HII_HANDLE             UefiHiiHandle
  )
{
  HII_THUNK_CONTEXT     *ThunkContext;

  ThunkContext = UefiHiiHandleToThunkContext (Private, UefiHiiHandle);
  ASSERT (ThunkContext != NULL);

  DestroyThunkContext (ThunkContext);
}


/**
  This function create a HII_THUNK_CONTEXT for the input UEFI HiiHandle
  that is created when a package list registered by a module calling 
  EFI_HII_DATABASE_PROTOCOL.NewPackageList. 
  This function records the PackageListGuid of EFI_HII_PACKAGE_LIST_HEADER 
  into the TagGuid of the created HII_THUNK_CONTEXT.

  @param UefiHiiHandle  The UEFI HII Handle.
  
  @return the new created Hii thunk context.

**/
HII_THUNK_CONTEXT *
CreateThunkContextForUefiHiiHandle (
  IN  EFI_HII_HANDLE             UefiHiiHandle
  )
{
  EFI_STATUS            Status;
  EFI_GUID              PackageGuid;
  HII_THUNK_CONTEXT      *ThunkContext;

  ThunkContext = AllocateZeroPool (sizeof (*ThunkContext));
  ASSERT (ThunkContext != NULL);
  
  ThunkContext->Signature = HII_THUNK_CONTEXT_SIGNATURE;

  Status = AllocateHiiHandle (&ThunkContext->FwHiiHandle);
  if (EFI_ERROR (Status)) {
    return NULL;
  }
  
  ThunkContext->UefiHiiHandle = UefiHiiHandle;
  
  Status = ExtractGuidFromHiiHandle (UefiHiiHandle, &PackageGuid);
  ASSERT_EFI_ERROR (Status);
  
  CopyGuid(&ThunkContext->TagGuid, &PackageGuid);

  return ThunkContext;
}


/**
  Get the number of HII Package for a Package type.

  @param PackageListHeader      The Package List.
  @param PackageType            The Package Type.

  @return The number of Package for given type.
**/
UINTN
GetPackageCountByType (
  IN CONST EFI_HII_PACKAGE_LIST_HEADER     *PackageListHeader,
  IN       UINT8                           PackageType
  )
{
  UINTN                     Count;
  EFI_HII_PACKAGE_HEADER    *PackageHeader;

  PackageHeader = (EFI_HII_PACKAGE_HEADER *) ((UINT8 *) PackageListHeader + sizeof (EFI_HII_PACKAGE_LIST_HEADER));
  Count = 0;
  
  while (PackageHeader->Type != EFI_HII_PACKAGE_END) {
    if (PackageHeader->Type == PackageType ) {
      Count++;
    }
    PackageHeader = (EFI_HII_PACKAGE_HEADER *) ((UINT8 *) PackageHeader + PackageHeader->Length);
  }
  
  
  return Count;
}

/**
  Get the Form Package from a Framework Package List.

  @param Packages               Framework Package List.

  @return The Form Package Header found.
**/
EFI_HII_PACKAGE_HEADER *
GetIfrPackage (
  IN CONST EFI_HII_PACKAGES               *Packages
  )
{
  UINTN                         Index;
  TIANO_AUTOGEN_PACKAGES_HEADER **TianoAutogenPackageHdrArray;

  ASSERT (Packages != NULL);

  TianoAutogenPackageHdrArray = (TIANO_AUTOGEN_PACKAGES_HEADER **) (((UINT8 *) &Packages->GuidId) + sizeof (Packages->GuidId));
  
  for (Index = 0; Index < Packages->NumberOfPackages; Index++) {
    //
    // The current UEFI HII build tool generate a binary in the format defined by 
    // TIANO_AUTOGEN_PACKAGES_HEADER. We assume that all packages generated in
    // this binary is with same package type. So the returned IfrPackageCount and StringPackageCount
    // may not be the exact number of valid package number in the binary generated 
    // by HII Build tool.
    //
    switch (TianoAutogenPackageHdrArray[Index]->FrameworkPackageHeader.Type) {
      case EFI_HII_IFR:
        return &TianoAutogenPackageHdrArray[Index]->PackageHeader;
        break;
      case EFI_HII_STRING:
      case EFI_HII_FONT:
        break;

      default:
        ASSERT (FALSE);
        return NULL;
        break;
    }
  }

  return NULL;
}

/**
  Get FormSet GUID.

  ASSERT if no FormSet Opcode is found.

  @param Packages             Form Framework Package.
  @param FormSetGuid          Return the FormSet Guid.

**/
VOID
GetFormSetGuid (
  IN  EFI_HII_PACKAGE_HEADER  *Package,
  OUT EFI_GUID                *FormSetGuid
  )
{
  UINTN                         Offset;
  EFI_IFR_OP_HEADER             *OpCode;
  EFI_IFR_FORM_SET              *FormSet;

  Offset = sizeof (EFI_HII_PACKAGE_HEADER);
  while (Offset < Package->Length) {
    OpCode = (EFI_IFR_OP_HEADER *)((UINT8 *) Package + Offset);

    switch (OpCode->OpCode) {
    case EFI_IFR_FORM_SET_OP:
      FormSet = (EFI_IFR_FORM_SET *) OpCode;
      CopyGuid (FormSetGuid, (EFI_GUID *)(VOID *)&FormSet->Guid);
      return;
      
      default:
        break;
      
    }
    Offset += OpCode->Length;
  }

  //
  // A proper IFR must have a formset opcode.
  //
  ASSERT (FALSE);

}

/**
  Creat a Thunk Context.

  ASSERT if no FormSet Opcode is found.

  @param Private             The HII Thunk Private Context.
  @param StringPackageCount  The String package count.
  @param IfrPackageCount     The IFR Package count.

  @return  A newly created Thunk Context.
  @retval  NULL  No resource to create a new Thunk Context.
**/
HII_THUNK_CONTEXT *
CreateThunkContext (
  IN  HII_THUNK_PRIVATE_DATA      *Private,
  IN  UINTN                       StringPackageCount,
  IN  UINTN                       IfrPackageCount
  )
{
  EFI_STATUS                   Status;
  HII_THUNK_CONTEXT            *ThunkContext;

  ThunkContext = AllocateZeroPool (sizeof (HII_THUNK_CONTEXT));
  ASSERT (ThunkContext != NULL);
  
  ThunkContext->Signature = HII_THUNK_CONTEXT_SIGNATURE;
  ThunkContext->IfrPackageCount = IfrPackageCount;
  ThunkContext->StringPackageCount = StringPackageCount;
  Status = AllocateHiiHandle (&ThunkContext->FwHiiHandle);
  if (EFI_ERROR (Status)) {
    return NULL;
  }

  return ThunkContext;
     
}

/**
  Destroy the Thunk Context and free up all resource.

  @param ThunkContext        The HII Thunk Private Context to be freed.

**/
VOID
DestroyThunkContext (
  IN HII_THUNK_CONTEXT          *ThunkContext
  )
{
  ASSERT (ThunkContext != NULL);

  FreeHiiHandle (ThunkContext->FwHiiHandle);

  RemoveEntryList (&ThunkContext->Link);

  if (ThunkContext->FormSet != NULL) {
    DestroyFormSet (ThunkContext->FormSet);
  }

  FreePool (ThunkContext);
}

/**
  Get the FormSet's Default Varstore ID based on the rule (Descending Priority):

  1) If VarStore ID of FRAMEWORK_RESERVED_VARSTORE_ID (0x01) is found, Var Store ID is used.
  2) If VarStore ID of FRAMEWORK_RESERVED_VARSTORE_ID is not found, First Var Store ID is used 
     as the default Var Store ID.

  @param FormSet The Form Set. The Default Varstore ID is updated if found.
  
**/
VOID
GetFormsetDefaultVarstoreId (
  IN OUT FORM_BROWSER_FORMSET  * FormSet
  )
{
  LIST_ENTRY             *StorageList;
  FORMSET_STORAGE        *Storage;

  //
  // VarStoreId 0 is invalid in UEFI IFR.
  //
  FormSet->DefaultVarStoreId = 0;
  StorageList = GetFirstNode (&FormSet->StorageListHead);

  while (!IsNull (&FormSet->StorageListHead, StorageList)) {
    Storage = FORMSET_STORAGE_FROM_LINK (StorageList);

    DEBUG ((EFI_D_INFO, "FormSet %g: Found Varstore ID %x Name %s Size 0x%x\n", &FormSet->Guid, Storage->VarStoreId, Storage->Name, Storage->Size));

    if (Storage->VarStoreId == FRAMEWORK_RESERVED_VARSTORE_ID) {
      //
      // 1) If VarStore ID of FRAMEWORK_RESERVED_VARSTORE_ID (0x01) is found, Var Store ID is used.
      //
      FormSet->DefaultVarStoreId = FRAMEWORK_RESERVED_VARSTORE_ID;
      break;
    }

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

  if (FormSet->DefaultVarStoreId != FRAMEWORK_RESERVED_VARSTORE_ID) {
    //
    // 
    // 2) If VarStore ID of FRAMEWORK_RESERVED_VARSTORE_ID is not found, First Var Store ID is used 
    //   as the default Var Store ID.
    //
    StorageList = GetFirstNode (&FormSet->StorageListHead);
    if (!IsNull (&FormSet->StorageListHead, StorageList)) {
      Storage = FORMSET_STORAGE_FROM_LINK (StorageList);
      FormSet->DefaultVarStoreId = Storage->VarStoreId;
    }
    
  }

  if (FormSet->DefaultVarStoreId == 0) {
    DEBUG ((EFI_D_INFO, "FormSet %g: No Varstore Found\n", &FormSet->Guid));
  } 
  
  return;
}

/**
  Fetch the Ifr binary data of a FormSet.

  @param  Handle                 PackageList Handle
  @param  FormSetGuid            GUID of a formset. If not specified (NULL or zero
                                 GUID), take the first FormSet found in package
                                 list.
  @param  BinaryLength           The length of the FormSet IFR binary.
  @param  BinaryData             The buffer designed to receive the FormSet.

  @retval EFI_SUCCESS            Buffer filled with the requested FormSet.
                                 BufferLength was updated.
  @retval EFI_INVALID_PARAMETER  The handle is unknown.
  @retval EFI_NOT_FOUND          A form or FormSet on the requested handle cannot
                                 be found with the requested FormId.

**/
EFI_STATUS
GetIfrBinaryData (
  IN  EFI_HII_HANDLE   Handle,
  IN OUT EFI_GUID      *FormSetGuid,
  OUT UINTN            *BinaryLength,
  OUT UINT8            **BinaryData
  )
{
  EFI_STATUS                   Status;
  EFI_HII_PACKAGE_LIST_HEADER  *HiiPackageList;
  UINTN                        BufferSize;
  UINT8                        *Package;
  UINT8                        *OpCodeData;
  UINT32                       Offset;
  UINT32                       Offset2;
  BOOLEAN                      ReturnDefault;
  UINT32                       PackageListLength;
  EFI_HII_PACKAGE_HEADER       PackageHeader;

  OpCodeData = NULL;
  Package = NULL;
  ZeroMem (&PackageHeader, sizeof (EFI_HII_PACKAGE_HEADER));;

  //
  // if FormSetGuid is NULL or zero GUID, return first FormSet in the package list
  //
  if (FormSetGuid == NULL || CompareGuid (FormSetGuid, &gZeroGuid)) {
    ReturnDefault = TRUE;
  } else {
    ReturnDefault = FALSE;
  }

  //
  // Get HII PackageList
  //
  BufferSize = 0;
  HiiPackageList = NULL;
  Status = mHiiDatabase->ExportPackageLists (mHiiDatabase, Handle, &BufferSize, HiiPackageList);
  if (Status == EFI_BUFFER_TOO_SMALL) {
    HiiPackageList = AllocatePool (BufferSize);
    ASSERT (HiiPackageList != NULL);

    Status = mHiiDatabase->ExportPackageLists (mHiiDatabase, Handle, &BufferSize, HiiPackageList);
  }
  if (EFI_ERROR (Status) || HiiPackageList == NULL) {
    return EFI_NOT_FOUND;
  }

  //
  // 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));

    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) {
          //
          // Check whether return default FormSet
          //
          if (ReturnDefault) {
            break;
          }

          //
          // FormSet GUID is specified, check it
          //
          if (CompareGuid (FormSetGuid, (EFI_GUID *)(OpCodeData + sizeof (EFI_IFR_OP_HEADER)))) {
            break;
          }
        }

        Offset2 += ((EFI_IFR_OP_HEADER *) OpCodeData)->Length;
      }

      if (Offset2 < PackageHeader.Length) {
        //
        // Target formset found
        //
        break;
      }
    }

    Offset += PackageHeader.Length;
  }

  if (Offset >= PackageListLength) {
    //
    // Form package not found in this Package List
    //
    gBS->FreePool (HiiPackageList);
    return EFI_NOT_FOUND;
  }

  if (ReturnDefault && FormSetGuid != NULL) {
    //
    // Return the default FormSet GUID
    //
    CopyMem (FormSetGuid, &((EFI_IFR_FORM_SET *) OpCodeData)->Guid, sizeof (EFI_GUID));
  }

  //
  // To determine the length of a whole FormSet IFR binary, one have to parse all the Opcodes
  // in this FormSet; So, here just simply copy the data from start of a FormSet to the end
  // of the Form Package.
  //
  *BinaryLength = PackageHeader.Length - Offset2;
  *BinaryData = AllocateCopyPool (*BinaryLength, OpCodeData);

  gBS->FreePool (HiiPackageList);

  if (*BinaryData == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  return EFI_SUCCESS;
}

/**
  Initialize the internal data structure of a FormSet.

  @param  Handle                 PackageList Handle
  @param  FormSetGuid            GUID of a formset. If not specified (NULL or zero
                                 GUID), take the first FormSet found in package
                                 list.
  @param  FormSet                FormSet data structure.

  @retval EFI_SUCCESS            The function completed successfully.
  @retval EFI_NOT_FOUND          The specified FormSet could not be found.

**/
EFI_STATUS
InitializeFormSet (
  IN  EFI_HII_HANDLE                   Handle,
  IN OUT EFI_GUID                      *FormSetGuid,
  OUT FORM_BROWSER_FORMSET             *FormSet
  )
{
  EFI_STATUS                Status;

  Status = GetIfrBinaryData (Handle, FormSetGuid, &FormSet->IfrBinaryLength, &FormSet->IfrBinaryData);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  FormSet->HiiHandle = Handle;
  CopyMem (&FormSet->Guid, FormSetGuid, sizeof (EFI_GUID));

  //
  // Parse the IFR binary OpCodes
  //
  Status = ParseOpCodes (FormSet);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  GetFormsetDefaultVarstoreId (FormSet);
  return Status;
}

/**
  Parse the Form Package and build a FORM_BROWSER_FORMSET structure.

  @param  UefiHiiHandle          PackageList Handle

  @return A pointer to FORM_BROWSER_FORMSET.

**/
FORM_BROWSER_FORMSET *
ParseFormSet (
  IN EFI_HII_HANDLE   UefiHiiHandle
  )
{
  FORM_BROWSER_FORMSET  *FormSet;
  EFI_GUID              FormSetGuid;
  EFI_STATUS            Status;
  
  FormSet = AllocateZeroPool (sizeof (FORM_BROWSER_FORMSET));    
  ASSERT (FormSet != NULL);

  CopyGuid (&FormSetGuid, &gZeroGuid);
  Status = InitializeFormSet (UefiHiiHandle, &FormSetGuid, FormSet);
  if (EFI_ERROR (Status)) {
    FreePool (FormSet);
    return NULL;
  }

  return FormSet;
}