1 ;------------------------------------------------------------------------------ 2 ; 3 ; Copyright (c) 2007, Intel Corporation. All rights reserved.<BR> 4 ; This program and the accompanying materials 5 ; are licensed and made available under the terms and conditions of the BSD License 6 ; which accompanies this distribution. The full text of the license may be found at 7 ; http://opensource.org/licenses/bsd-license.php 8 ; 9 ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 10 ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 11 ; 12 ; Module Name: 13 ; 14 ; Stack.asm 15 ; 16 ; Abstract: 17 ; 18 ; Switch the stack from temporary memory to permenent memory. 19 ; 20 ;------------------------------------------------------------------------------ 21 22 .586p 23 .model flat,C 24 .code 25 26 ;------------------------------------------------------------------------------ 27 ; VOID 28 ; EFIAPI 29 ; SecSwitchStack ( 30 ; UINT32 TemporaryMemoryBase, 31 ; UINT32 PermenentMemoryBase 32 ; ); 33 ;------------------------------------------------------------------------------ 34 SecSwitchStack PROC 35 ; 36 ; Save three register: eax, ebx, ecx 37 ; 38 push eax 39 push ebx 40 push ecx 41 push edx 42 43 ; 44 ; !!CAUTION!! this function address's is pushed into stack after 45 ; migration of whole temporary memory, so need save it to permenent 46 ; memory at first! 47 ; 48 49 mov ebx, [esp + 20] ; Save the first parameter 50 mov ecx, [esp + 24] ; Save the second parameter 51 52 ; 53 ; Save this function's return address into permenent memory at first. 54 ; Then, Fixup the esp point to permenent memory 55 ; 56 mov eax, esp 57 sub eax, ebx 58 add eax, ecx 59 mov edx, dword ptr [esp] ; copy pushed register's value to permenent memory 60 mov dword ptr [eax], edx 61 mov edx, dword ptr [esp + 4] 62 mov dword ptr [eax + 4], edx 63 mov edx, dword ptr [esp + 8] 64 mov dword ptr [eax + 8], edx 65 mov edx, dword ptr [esp + 12] 66 mov dword ptr [eax + 12], edx 67 mov edx, dword ptr [esp + 16] ; Update this function's return address into permenent memory 68 mov dword ptr [eax + 16], edx 69 mov esp, eax ; From now, esp is pointed to permenent memory 70 71 ; 72 ; Fixup the ebp point to permenent memory 73 ; 74 mov eax, ebp 75 sub eax, ebx 76 add eax, ecx 77 mov ebp, eax ; From now, ebp is pointed to permenent memory 78 79 ; 80 ; Fixup callee's ebp point for PeiDispatch 81 ; 82 mov eax, dword ptr [ebp] 83 sub eax, ebx 84 add eax, ecx 85 mov dword ptr [ebp], eax ; From now, Temporary's PPI caller's stack is in permenent memory 86 87 pop edx 88 pop ecx 89 pop ebx 90 pop eax 91 ret 92 SecSwitchStack ENDP 93 94 END 95
