1 files changed, 95 insertions, 0 deletions
diff --git a/EmulatorPkg/Sec/Ia32/SwitchRam.S b/EmulatorPkg/Sec/Ia32/SwitchRam.S
new file mode 100644
index 0000000000..81e478be82
--- /dev/null
+++ b/EmulatorPkg/Sec/Ia32/SwitchRam.S
@@ -0,0 +1,95 @@
+#------------------------------------------------------------------------------
+#
+# Copyright (c) 2007, 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.
+#
+# Module Name:
+#
+#   Stack.asm
+#
+# Abstract:
+#
+#   Switch the stack from temporary memory to permenent memory.
+#
+#------------------------------------------------------------------------------
+
+ .text
+ 
+
+//------------------------------------------------------------------------------
+// VOID
+// EFIAPI
+// SecSwitchStack (
+//   UINT32   TemporaryMemoryBase,
+//   UINT32   PermenentMemoryBase
+//   )//
+//------------------------------------------------------------------------------    
+ASM_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 permenent
+# memory at first!
+#    
+    
+    movl  20(%esp), %ebx            # Save the first parameter
+    movl  24(%esp), %ecx            # Save the second parameter
+    
+#
+# Save this function's return address into permenent memory at first.
+# Then, Fixup the esp point to permenent memory
+#
+
+    movl  %esp, %eax
+    subl  %ebx, %eax
+    addl  %ecx, %eax
+    movl  (%esp), %edx                 # copy pushed register's value to permenent memory
+    movl  %edx, (%eax)
+    movl  4(%esp), %edx
+    movl  %edx, 4(%eax)
+    movl  8(%esp), %edx
+    movl  %edx, 8(%eax)
+    movl  12(%esp), %edx
+    movl  %edx, 12(%eax)
+    movl  16(%esp), %edx
+    movl  %edx, 16(%eax)
+    movl  %eax, %esp                   # From now, esp is pointed to permenent memory
+
+#
+# Fixup the ebp point to permenent memory
+#
+#ifndef __APPLE__
+    movl   %ebp, %eax
+    subl   %ebx, %eax
+    addl   %ecx, %eax
+    movl   %eax, %ebp                  # From now, ebp is pointed to permenent memory
+    
+#
+# Fixup callee's ebp point for PeiDispatch
+#    
+    movl   (%ebp), %eax
+    subl   %ebx, %eax
+    addl   %ecx, %eax
+    movl   %eax, (%ebp)                # From now, Temporary's PPI caller's stack is in permenent memory
+#endif    
+    
+    pop   %edx
+    pop   %ecx
+    pop   %ebx
+    pop   %eax
+    ret
+