audk/MdePkg/Library/BaseLib/Ia32/InternalSwitchStack.nasm

48 lines
1.6 KiB
NASM

;------------------------------------------------------------------------------
;
; Copyright (c) 2016, Intel Corporation. All rights reserved.<BR>
; Portions copyright (c) 2011, Apple Inc. 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.
;
; Module Name:
;
; InternalSwitchStack.nasm
;
; Abstract:
;
; Implementation of a stack switch on IA-32.
;
;------------------------------------------------------------------------------
SECTION .text
;------------------------------------------------------------------------------
; VOID
; EFIAPI
; InternalSwitchStack (
; IN SWITCH_STACK_ENTRY_POINT EntryPoint,
; IN VOID *Context1, OPTIONAL
; IN VOID *Context2, OPTIONAL
; IN VOID *NewStack
; );
;------------------------------------------------------------------------------
global ASM_PFX(InternalSwitchStack)
ASM_PFX(InternalSwitchStack):
push ebp
mov ebp, esp
mov esp, [ebp + 20] ; switch stack
sub esp, 8
mov eax, [ebp + 16]
mov [esp + 4], eax
mov eax, [ebp + 12]
mov [esp], eax
push 0 ; keeps gdb from unwinding stack
jmp dword [ebp + 8] ; call and never return