audk/IntelFspPkg/Library/BaseFspSwitchStackLib/Ia32/Stack.asm

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;------------------------------------------------------------------------------
;
; 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.
;
; Abstract:
;
; Switch the stack from temporary memory to permenent memory.
;
;------------------------------------------------------------------------------
.586p
.model flat,C
.code
;------------------------------------------------------------------------------
; UINT32
; EFIAPI
; Pei2LoaderSwitchStack (
; VOID
; )
;------------------------------------------------------------------------------
EXTERNDEF C MeasurePoint:PROC
Pei2LoaderSwitchStack PROC C PUBLIC
jmp Loader2PeiSwitchStack
Pei2LoaderSwitchStack ENDP
;------------------------------------------------------------------------------
; UINT32
; EFIAPI
; Loader2PeiSwitchStack (
; VOID
; )
;------------------------------------------------------------------------------
EXTERNDEF C SwapStack:PROC
Loader2PeiSwitchStack PROC C PUBLIC
; Save current contexts
push offset exit
pushfd
cli
pushad
sub esp, 8
sidt fword ptr [esp]
; Load new stack
push esp
call SwapStack
mov esp, eax
; Restore previous contexts
lidt fword ptr [esp]
add esp, 8
popad
popfd
exit:
ret
Loader2PeiSwitchStack ENDP
END