IntelFsp2Pkg/Library/BaseFspSwitchStackLib/FspSwitchStackLib.c

   1 /** @file
   2
   3   Copyright (c) 2014, Intel Corporation. All rights reserved.<BR>
   4   This program and the accompanying materials
   5   are licensed and made available under the terms and conditions of the BSD License
   6   which accompanies this distribution.  The full text of the license may be found at
   7   http://opensource.org/licenses/bsd-license.php.
   8
   9   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12 **/
  13
  14 #include <Base.h>
  15 #include <Library/BaseLib.h>
  16 #include <Library/FspCommonLib.h>
  17
  18 /**
  19
  20   Switch the current stack to the previous saved stack.
  21
  22   @param[in]  NewStack         The new stack to be switched.
  23
  24   @return OldStack         After switching to the saved stack,
  25                            this value will be saved in eax before returning.
  26
  27
  28 **/
  29 UINT32
  30 SwapStack (
  31   IN  UINT32 NewStack
  32   )
  33 {
  34   FSP_GLOBAL_DATA  *FspData;
  35   UINT32         OldStack;
  36
  37   FspData  = GetFspGlobalDataPointer ();
  38   OldStack = FspData->CoreStack;
  39   FspData->CoreStack = NewStack;
  40   return OldStack;
  41 }
  42