1 files changed, 43 insertions, 0 deletions
diff --git a/MdePkg/Library/BaseLib/X64/DisableCache.nasm b/MdePkg/Library/BaseLib/X64/DisableCache.nasm
new file mode 100644
index 0000000000000..9f565b1ec3c86
--- /dev/null
+++ b/MdePkg/Library/BaseLib/X64/DisableCache.nasm
@@ -0,0 +1,43 @@
+;------------------------------------------------------------------------------
+;
+; 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.Asm
+;
+; 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:
+;
+;------------------------------------------------------------------------------
+
+    DEFAULT REL
+    SECTION .text
+
+;------------------------------------------------------------------------------
+; VOID
+; EFIAPI
+; AsmDisableCache (
+;   VOID
+;   );
+;------------------------------------------------------------------------------
+global ASM_PFX(AsmDisableCache)
+ASM_PFX(AsmDisableCache):
+    mov     rax, cr0
+    bts     rax, 30
+    btr     rax, 29
+    mov     cr0, rax
+    wbinvd
+    ret
+