1;------------------------------------------------------------------------------
2;
3; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
4; This program and the accompanying materials
5; are licensed and made available under the terms and conditions of the BSD License
6; which accompanies this distribution.  The full text of the license may be found at
7; http://opensource.org/licenses/bsd-license.php.
8;
9; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
10; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
11;
12; Module Name:
13;
14;   WriteDr5.Asm
15;
16; Abstract:
17;
18;   AsmWriteDr5 function
19;
20; Notes:
21;
22;------------------------------------------------------------------------------
23
24    SECTION .text
25
26;------------------------------------------------------------------------------
27; UINTN
28; EFIAPI
29; AsmWriteDr5 (
30;   IN UINTN Value
31;   );
32;------------------------------------------------------------------------------
33global ASM_PFX(AsmWriteDr5)
34ASM_PFX(AsmWriteDr5):
35    mov     eax, [esp + 4]
36    ;
37    ; DR5 is alias to DR7 only if DE (in CR4) is cleared. Otherwise, writing to
38    ; this register will cause a #UD exception.
39    ;
40    ; MS assembler doesn't support this instruction since no one would use it
41    ; under normal circustances. Here opcode is used.
42    ;
43    DB      0xf, 0x23, 0xe8
44    ret
45
46