Add EnableCache() and DisableCache() implementations for IA32 and X64 to the BaseLib

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@6705 6f19259b-4bc3-4df7-8a09-765794883524

MdePkg/Library/BaseLib/Ia32/DisableCache.S

@@ -0,0 +1,39 @@
+#------------------------------------------------------------------------------
+#
+# Copyright (c) 2006 - 2008, 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:
+#
+#   DisableCache.S
+#
+# Abstract:
+#
+#   Set the CD bit of CR0 to 1, clear the NW bit of CR0 to 0, and flush all caches with a
+#   WBINVD instruction.
+#
+# Notes:
+#
+#------------------------------------------------------------------------------
+
+#------------------------------------------------------------------------------
+# VOID
+# EFIAPI
+# AsmDisableCache (
+#   VOID
+#   );
+#------------------------------------------------------------------------------
+.globl ASM_PFX(AsmDisableCache)
+ASM_PFX(AsmDisableCache):
+    movl    %cr0, %eax
+    btsl    $30, %eax
+    btrl    $29, %eax
+    movl    %eax, %cr0
+    wbinvd
+    ret