1 files changed, 39 insertions, 0 deletions
diff --git a/UnixPkg/Library/UnixBaseLib/X64/DisableCache.S b/UnixPkg/Library/UnixBaseLib/X64/DisableCache.S
new file mode 100644
index 0000000000..970f2f3618
--- /dev/null
+++ b/UnixPkg/Library/UnixBaseLib/X64/DisableCache.S
@@ -0,0 +1,39 @@
+#------------------------------------------------------------------------------
+#
+# Copyright (c) 2006 - 2008, 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:
+#
+#   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
+#   );
+#------------------------------------------------------------------------------
+ASM_GLOBAL ASM_PFX(AsmDisableCache)
+ASM_PFX(AsmDisableCache):
+    movq    %cr0, %rax
+    btsq    $30, %rax
+    btrq    $29, %rax
+    movq    %rax, %cr0
+    wbinvd
+    ret