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;------------------------------------------------------------------------------
;
; Copyright (c) 2007, Intel Corporation
; All rights reserved. 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:
;
; Stack.asm
;
; Abstract:
;
; Switch the stack from temporary memory to permenent memory.
;
;------------------------------------------------------------------------------
.586p
.model flat,C
.code
;------------------------------------------------------------------------------
; VOID
; EFIAPI
; SecSwitchStack (
; UINT32 TemporaryMemoryBase,
; UINT32 PermenentMemoryBase
; );
;------------------------------------------------------------------------------
SecSwitchStack PROC
;
; 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 permenent
; 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 permenent memory at first.
; Then, Fixup the esp point to permenent memory
;
mov eax, esp
sub eax, ebx
add eax, ecx
mov edx, dword ptr [esp] ; copy pushed register's value to permenent memory
mov dword ptr [eax], edx
mov edx, dword ptr [esp + 4]
mov dword ptr [eax + 4], edx
mov edx, dword ptr [esp + 8]
mov dword ptr [eax + 8], edx
mov edx, dword ptr [esp + 12]
mov dword ptr [eax + 12], edx
mov edx, dword ptr [esp + 16] ; Update this function's return address into permenent memory
mov dword ptr [eax + 16], edx
mov esp, eax ; From now, esp is pointed to permenent memory
;
; Fixup the ebp point to permenent memory
;
mov eax, ebp
sub eax, ebx
add eax, ecx
mov ebp, eax ; From now, ebp is pointed to permenent memory
;
; Fixup callee's ebp point for PeiDispatch
;
mov eax, dword ptr [ebp]
sub eax, ebx
add eax, ecx
mov dword ptr [ebp], eax ; From now, Temporary's PPI caller's stack is in permenent memory
pop edx
pop ecx
pop ebx
pop eax
ret
SecSwitchStack ENDP
END
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