Initial port to x86_64 gnu assembly.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@1959 6f19259b-4bc3-4df7-8a09-765794883524

MdePkg/Library/BaseLib/X64/SwitchStack.S

@@ -0,0 +1,44 @@
+#------------------------------------------------------------------------------
+#
+# Copyright (c) 2006, Intel Corporation
+# 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:
+#
+#   SwitchStack.S
+#
+# Abstract:
+#
+#------------------------------------------------------------------------------
+
+
+#------------------------------------------------------------------------------
+# Routine Description:
+#
+#   Routine for switching stacks with 1 parameter
+#
+# Arguments:
+#
+#   (rdi) EntryPoint    - Entry point with new stack.
+#   (rsi) Context1      - Parameter1 for entry point.
+#   (rdx)  Context2     - Parameter2 for entry point.
+#   (rcx)  NewStack     - Pointer to new stack.
+#
+# Returns:
+#
+#   None
+#
+#------------------------------------------------------------------------------
+.global _InternalSwitchStack;
+_InternalSwitchStack:
+    mov     %rcx, %rax
+    mov     %rdx, %rcx
+    mov     %r8, %rdx
+    lea     -0x20(%r9), %rsp
+    call    *%rax