diff options
Diffstat (limited to 'Platform/BroxtonPlatformPkg/Common/SampleCode/IntelFsp2WrapperPkg/Library/SecPeiFspPlatformSecLibSample/Ia32/Stack.asm')
-rw-r--r-- | Platform/BroxtonPlatformPkg/Common/SampleCode/IntelFsp2WrapperPkg/Library/SecPeiFspPlatformSecLibSample/Ia32/Stack.asm | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/Platform/BroxtonPlatformPkg/Common/SampleCode/IntelFsp2WrapperPkg/Library/SecPeiFspPlatformSecLibSample/Ia32/Stack.asm b/Platform/BroxtonPlatformPkg/Common/SampleCode/IntelFsp2WrapperPkg/Library/SecPeiFspPlatformSecLibSample/Ia32/Stack.asm new file mode 100644 index 0000000000..42d6e9a990 --- /dev/null +++ b/Platform/BroxtonPlatformPkg/Common/SampleCode/IntelFsp2WrapperPkg/Library/SecPeiFspPlatformSecLibSample/Ia32/Stack.asm @@ -0,0 +1,81 @@ +;; @file
+; Switch the stack from temporary memory to permenent memory.
+;
+; Copyright (c) 2014 - 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
+;
+;;
+
+ .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
+
+ pop edx
+ pop ecx
+ pop ebx
+ pop eax
+ ret
+SecSwitchStack ENDP
+
+ END
+
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