Add IntelFspPkg to support create FSP bin based on EDKII.

Contributed-under: TianoCore Contribution Agreement 1.0

Signed off by: Ravi Rangarajan <ravi.p.rangarajan@intel.com>
Reviewed by: Maurice Ma <maurice.ma@intel.com>
Reviewed by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed by: Giri Mudusuru <giri.p.mudusuru@intel.com>
Reviewed by: Liming Gao <liming.gao@intel.com>


git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15705 6f19259b-4bc3-4df7-8a09-765794883524

IntelFspPkg/Include/Library/FspSwitchStackLib.h

@@ -0,0 +1,45 @@
+/** @file
+
+  Copyright (c) 2014, 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.
+
+**/
+
+#ifndef _FSP_SWITCH_STACK_LIB_H_
+#define _FSP_SWITCH_STACK_LIB_H_
+
+/**
+
+  This funciton will switch the current stack to the previous saved stack.
+  Before calling the previous stack has to be set in  FSP_GLOBAL_DATA.CoreStack.
+                    EIP
+                    FLAGS  16 bit  FLAGS  16 bit
+                    EDI
+                    ESI
+                    EBP
+                    ESP
+                    EBX
+                    EDX
+                    ECX
+                    EAX
+                    DWORD     IDT base1
+  StackPointer:     DWORD     IDT base2
+
+  @return ReturnKey          After switching to the saved stack,
+                             this value will be saved in eax before returning.
+
+
+**/
+UINT32
+EFIAPI
+Pei2LoaderSwitchStack (
+  VOID
+  );
+
+#endif