1 files changed, 78 insertions, 0 deletions
diff --git a/CorebootModulePkg/SecCore/Ia32/Stack.nasm b/CorebootModulePkg/SecCore/Ia32/Stack.nasm
new file mode 100644
index 0000000000..f3362f6045
--- /dev/null
+++ b/CorebootModulePkg/SecCore/Ia32/Stack.nasm
@@ -0,0 +1,78 @@
+;------------------------------------------------------------------------------
+;
+; Copyright (c) 2015 - 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 permanent memory.
+;
+;------------------------------------------------------------------------------
+
+SECTION .text
+
+;------------------------------------------------------------------------------
+; VOID
+; EFIAPI
+; SecSwitchStack (
+;   UINT32   TemporaryMemoryBase,
+;   UINT32   PermenentMemoryBase
+;   );
+;------------------------------------------------------------------------------
+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,  [esp]               ; copy pushed register's value to permanent memory
+    mov   [eax], edx
+    mov   edx,  [esp + 4]
+    mov   [eax + 4], edx
+    mov   edx,  [esp + 8]
+    mov   [eax + 8], edx
+    mov   edx,  [esp + 12]
+    mov   [eax + 12], edx
+    mov   edx,  [esp + 16]          ; Update return address into permanent memory
+    mov   [eax + 16], edx
+    mov   esp,  eax                 ; From now, esp is pointed to permanent 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 permanent memory
+
+    pop   edx
+    pop   ecx
+    pop   ebx
+    pop   eax
+    ret