ArmPlatformPkg: Added Aarch64 support

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Harry Liebel <Harry.Liebel@arm.com>
Signed-off-by: Olivier Martin <olivier.martin@arm.com>



git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14489 6f19259b-4bc3-4df7-8a09-765794883524

ArmPlatformPkg/PrePeiCore/AArch64/SwitchStack.S

@@ -0,0 +1,43 @@
+#------------------------------------------------------------------------------
+#
+# Copyright (c) 2006 - 2009, Intel Corporation. All rights reserved.<BR>
+# Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
+# Portions copyright (c) 2011 - 2013, ARM Ltd. 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.
+#
+#------------------------------------------------------------------------------
+
+.text
+.align 3
+
+ASM_GLOBAL ASM_PFX(SecSwitchStack)
+
+
+
+#/**
+#  This allows the caller to switch the stack and return
+#
+# @param      StackDelta     Signed amount by which to modify the stack pointer
+#
+# @return     Nothing. Goes to the Entry Point passing in the new parameters
+#
+#**/
+#VOID
+#EFIAPI
+#SecSwitchStack (
+#  VOID  *StackDelta
+#  )#
+#
+ASM_PFX(SecSwitchStack):
+    mov   x1, sp
+    add   x1, x0, x1
+    mov   sp, x1
+    ret
+