diff --git a/IntelFsp2Pkg/Include/FspGlobalData.h b/IntelFsp2Pkg/Include/FspGlobalData.h
index 5bde316893..dba9b48e1a 100644
--- a/IntelFsp2Pkg/Include/FspGlobalData.h
+++ b/IntelFsp2Pkg/Include/FspGlobalData.h
@@ -52,12 +52,20 @@ typedef struct  {
    VOID               *MemoryInitUpdPtr;
    VOID               *SiliconInitUpdPtr;
    UINT8              ApiIdx;
-   UINT8              FspMode; // 0: FSP in API mode; 1: FSP in DISPATCH mode
+   ///
+   /// 0: FSP in API mode; 1: FSP in DISPATCH mode
+   ///
+   UINT8              FspMode;
    UINT8              OnSeparateStack;
    UINT8              Reserved3;
    UINT32             NumberOfPhases;
    UINT32             PhasesExecuted;
-   UINT8              Reserved4[20];
+   ///
+   /// To store function parameters pointer
+   /// so it can be retrieved after stack switched.
+   ///
+   VOID               *FunctionParameterPtr;
+   UINT8              Reserved4[16];
    UINT32             PerfSig;
    UINT16             PerfLen;
    UINT16             Reserved5;
diff --git a/IntelFsp2Pkg/Include/Library/FspSwitchStackLib.h b/IntelFsp2Pkg/Include/Library/FspSwitchStackLib.h
index 0c76e9f022..f049361d78 100644
--- a/IntelFsp2Pkg/Include/Library/FspSwitchStackLib.h
+++ b/IntelFsp2Pkg/Include/Library/FspSwitchStackLib.h
@@ -1,6 +1,6 @@
 /** @file
 
-  Copyright (c) 2014, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2014 - 2020, Intel Corporation. All rights reserved.<BR>
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
@@ -36,4 +36,20 @@ Pei2LoaderSwitchStack (
   VOID
   );
 
+/**
+
+  This function is equivalent to Pei2LoaderSwitchStack () but just indicates
+  the stack after switched is FSP stack.
+
+  @return ReturnKey          After switching to the saved stack,
+                             this value will be saved in eax before returning.
+
+
+**/
+UINT32
+EFIAPI
+Loader2PeiSwitchStack (
+  VOID
+  );
+
 #endif