diff options
Diffstat (limited to 'UnixPkg/Sec/Ia32/Stack.S')
-rw-r--r-- | UnixPkg/Sec/Ia32/Stack.S | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/UnixPkg/Sec/Ia32/Stack.S b/UnixPkg/Sec/Ia32/Stack.S new file mode 100644 index 0000000000..4716af9a9f --- /dev/null +++ b/UnixPkg/Sec/Ia32/Stack.S @@ -0,0 +1,95 @@ +#------------------------------------------------------------------------------
+#
+# Copyright (c) 2008 - 2009, Intel Corporation
+# Portions copyright (c) 2008-2009 Apple Inc.
+# All rights reserved. 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.
+#
+#------------------------------------------------------------------------------
+
+#------------------------------------------------------------------------------
+# VOID
+# EFIAPI
+# SecSwitchStack (
+# UINT32 TemporaryMemoryBase,
+# UINT32 PermenentMemoryBase
+# );
+#------------------------------------------------------------------------------
+
+#include <ProcessorBind.h>
+
+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
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