audk/IntelFsp2Pkg/Library/BaseFspSwitchStackLib/Ia32/Stack.nasm

75 lines
2.1 KiB
NASM

;------------------------------------------------------------------------------
;
; Copyright (c) 2016, 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.
;
;------------------------------------------------------------------------------
SECTION .text
extern ASM_PFX(SwapStack)
;------------------------------------------------------------------------------
; UINT32
; EFIAPI
; Pei2LoaderSwitchStack (
; VOID
; )
;------------------------------------------------------------------------------
global ASM_PFX(Pei2LoaderSwitchStack)
ASM_PFX(Pei2LoaderSwitchStack):
xor eax, eax
jmp ASM_PFX(FspSwitchStack)
;------------------------------------------------------------------------------
; UINT32
; EFIAPI
; Loader2PeiSwitchStack (
; VOID
; )
;------------------------------------------------------------------------------
global ASM_PFX(Loader2PeiSwitchStack)
ASM_PFX(Loader2PeiSwitchStack):
jmp ASM_PFX(FspSwitchStack)
;------------------------------------------------------------------------------
; UINT32
; EFIAPI
; FspSwitchStack (
; VOID
; )
;------------------------------------------------------------------------------
global ASM_PFX(FspSwitchStack)
ASM_PFX(FspSwitchStack):
; Save current contexts
push eax
pushfd
cli
pushad
sub esp, 8
sidt [esp]
; Load new stack
push esp
call ASM_PFX(SwapStack)
mov esp, eax
; Restore previous contexts
lidt [esp]
add esp, 8
popad
popfd
add esp, 4
ret