mirror of https://github.com/acidanthera/audk.git
80 lines
2.5 KiB
NASM
80 lines
2.5 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
|
||
|
|
|
||
|
|
;------------------------------------------------------------------------------
|
||
|
|
; VOID
|
||
|
|
; EFIAPI
|
||
|
|
; SecSwitchStack (
|
||
|
|
; UINT32 TemporaryMemoryBase,
|
||
|
|
; UINT32 PermanentMemoryBase
|
||
|
|
; );
|
||
|
|
;------------------------------------------------------------------------------
|
||
|
|
global ASM_PFX(SecSwitchStack)
|
||
|
|
ASM_PFX(SecSwitchStack):
|
||
|
|
;
|
||
|
|
; Save three register: eax, ebx, ecx
|
||
|
|
;
|
||
|
|
push eax
|
||
|
|
push ebx
|
||
|
|
push ecx
|
||
|
|
push edx
|
||
|
|
|
||
|
|
;
|
||
|
|
; !!CAUTION!! this function address's is pushed into stack after
|
||
|
|
; migration of whole temporary memory, so need save it to permanent
|
||
|
|
; memory at first!
|
||
|
|
;
|
||
|
|
|
||
|
|
mov ebx, [esp + 20] ; Save the first parameter
|
||
|
|
mov ecx, [esp + 24] ; Save the second parameter
|
||
|
|
|
||
|
|
;
|
||
|
|
; Save this function's return address into permanent memory at first.
|
||
|
|
; Then, Fixup the esp point to permanent memory
|
||
|
|
;
|
||
|
|
mov eax, esp
|
||
|
|
sub eax, ebx
|
||
|
|
add eax, ecx
|
||
|
|
mov edx, dword [esp] ; copy pushed register's value to permanent memory
|
||
|
|
mov dword [eax], edx
|
||
|
|
mov edx, dword [esp + 4]
|
||
|
|
mov dword [eax + 4], edx
|
||
|
|
mov edx, dword [esp + 8]
|
||
|
|
mov dword [eax + 8], edx
|
||
|
|
mov edx, dword [esp + 12]
|
||
|
|
mov dword [eax + 12], edx
|
||
|
|
mov edx, dword [esp + 16] ; Update this function's return address into permanent memory
|
||
|
|
mov dword [eax + 16], edx
|
||
|
|
mov esp, eax ; From now, esp is pointed to permanent memory
|
||
|
|
|
||
|
|
;
|
||
|
|
; Fixup the ebp point to permanent memory
|
||
|
|
;
|
||
|
|
mov eax, ebp
|
||
|
|
sub eax, ebx
|
||
|
|
add eax, ecx
|
||
|
|
mov ebp, eax ; From now, ebp is pointed to permanent memory
|
||
|
|
|
||
|
|
pop edx
|
||
|
|
pop ecx
|
||
|
|
pop ebx
|
||
|
|
pop eax
|
||
|
|
ret
|
||
|
|
|