Add IntelFsp2Pkg and IntelFsp2WrapperPkg.

[mirror_edk2.git] / IntelFsp2WrapperPkg / Library / SecFspWrapperPlatformSecLibSample / Ia32 / Stack.asm

diff --git a/IntelFsp2WrapperPkg/Library/SecFspWrapperPlatformSecLibSample/Ia32/Stack.asm b/IntelFsp2WrapperPkg/Library/SecFspWrapperPlatformSecLibSample/Ia32/Stack.asm
new file mode 100644 (file)
index 0000000..116b738
--- /dev/null
+++ b/IntelFsp2WrapperPkg/Library/SecFspWrapperPlatformSecLibSample/Ia32/Stack.asm
@@ -0,0 +1,82 @@
+;------------------------------------------------------------------------------\r
+;\r
+; Copyright (c) 2014, Intel Corporation. All rights reserved.<BR>\r
+; This program and the accompanying materials\r
+; are licensed and made available under the terms and conditions of the BSD License\r
+; which accompanies this distribution.  The full text of the license may be found at\r
+; http://opensource.org/licenses/bsd-license.php.\r
+;\r
+; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
+; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
+;\r
+; Abstract:\r
+;\r
+;   Switch the stack from temporary memory to permenent memory.\r
+;\r
+;------------------------------------------------------------------------------\r
+\r
+    .586p\r
+    .model  flat,C\r
+    .code\r
+\r
+;------------------------------------------------------------------------------\r
+; VOID\r
+; EFIAPI\r
+; SecSwitchStack (\r
+;   UINT32   TemporaryMemoryBase,\r
+;   UINT32   PermanentMemoryBase\r
+;   );\r
+;------------------------------------------------------------------------------\r
+SecSwitchStack   PROC\r
+    ;\r
+    ; Save three register: eax, ebx, ecx\r
+    ;\r
+    push  eax\r
+    push  ebx\r
+    push  ecx\r
+    push  edx\r
+\r
+    ;\r
+    ; !!CAUTION!! this function address's is pushed into stack after\r
+    ; migration of whole temporary memory, so need save it to permanent\r
+    ; memory at first!\r
+    ;\r
+\r
+    mov   ebx, [esp + 20]          ; Save the first parameter\r
+    mov   ecx, [esp + 24]          ; Save the second parameter\r
+\r
+    ;\r
+    ; Save this function's return address into permanent memory at first.\r
+    ; Then, Fixup the esp point to permanent memory\r
+    ;\r
+    mov   eax, esp\r
+    sub   eax, ebx\r
+    add   eax, ecx\r
+    mov   edx, dword ptr [esp]         ; copy pushed register's value to permanent memory\r
+    mov   dword ptr [eax], edx\r
+    mov   edx, dword ptr [esp + 4]\r
+    mov   dword ptr [eax + 4], edx\r
+    mov   edx, dword ptr [esp + 8]\r
+    mov   dword ptr [eax + 8], edx\r
+    mov   edx, dword ptr [esp + 12]\r
+    mov   dword ptr [eax + 12], edx\r
+    mov   edx, dword ptr [esp + 16]    ; Update this function's return address into permanent memory\r
+    mov   dword ptr [eax + 16], edx\r
+    mov   esp, eax                     ; From now, esp is pointed to permanent memory\r
+\r
+    ;\r
+    ; Fixup the ebp point to permanent memory\r
+    ;\r
+    mov   eax, ebp\r
+    sub   eax, ebx\r
+    add   eax, ecx\r
+    mov   ebp, eax                ; From now, ebp is pointed to permanent memory\r
+\r
+    pop   edx\r
+    pop   ecx\r
+    pop   ebx\r
+    pop   eax\r
+    ret\r
+SecSwitchStack   ENDP\r
+\r
+    END\r