1 files changed, 43 insertions, 0 deletions
diff --git a/MdePkg/Library/BaseLib/X64/WriteDr4.asm b/MdePkg/Library/BaseLib/X64/WriteDr4.asm
new file mode 100644
index 000000000000..6e7bca9b9994
--- /dev/null
+++ b/MdePkg/Library/BaseLib/X64/WriteDr4.asm
@@ -0,0 +1,43 @@
+;------------------------------------------------------------------------------
+;
+; Copyright (c) 2006, 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:
+;
+;   WriteDr4.Asm
+;
+; Abstract:
+;
+;   AsmWriteDr4 function
+;
+; Notes:
+;
+;------------------------------------------------------------------------------
+
+    .code
+
+;------------------------------------------------------------------------------
+; UINTN
+; EFIAPI
+; AsmWriteDr4 (
+;   IN UINTN Value
+;   );
+;------------------------------------------------------------------------------
+AsmWriteDr4 PROC
+    ;
+    ; There's no obvious reason to access this register, since it's aliased to
+    ; DR6 when DE=0 or an exception generated when DE=1
+    ;
+    DB      0fh, 23h, 0e1h
+    mov     rax, rcx
+    ret
+AsmWriteDr4 ENDP
+
+    END