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

69 lines
1.7 KiB
NASM

;------------------------------------------------------------------------------
;
; Copyright (c) 2016, Intel Corporation. All rights reserved.<BR>
; SPDX-License-Identifier: BSD-2-Clause-Patent
;
; 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