IntelFsp2Pkg/Library/BaseFspSwitchStackLib/FspSwitchStackLib.c

   1 /** @file
   2
   3   Copyright (c) 2014 - 2022, Intel Corporation. All rights reserved.<BR>
   4   SPDX-License-Identifier: BSD-2-Clause-Patent
   5
   6 **/
   7
   8 #include <Base.h>
   9 #include <Library/BaseLib.h>
  10 #include <Library/FspCommonLib.h>
  11
  12 /**
  13
  14   Switch the current stack to the previous saved stack.
  15
  16   @param[in]  NewStack         The new stack to be switched.
  17
  18   @return OldStack         After switching to the saved stack,
  19                            this value will be saved in eax before returning.
  20
  21
  22 **/
  23 UINTN
  24 EFIAPI
  25 SwapStack (
  26   IN  UINTN  NewStack
  27   )
  28 {
  29   FSP_GLOBAL_DATA  *FspData;
  30   UINTN            OldStack;
  31
  32   FspData            = GetFspGlobalDataPointer ();
  33   OldStack           = FspData->CoreStack;
  34   FspData->CoreStack = (UINTN) NewStack;
  35   return OldStack;
  36 }