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1;------------------------------------------------------------------------------\r
2;\r
3; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>\r
9344f092 4; SPDX-License-Identifier: BSD-2-Clause-Patent\r
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5;\r
6; Module Name:\r
7;\r
8; ReadDr5.Asm\r
9;\r
10; Abstract:\r
11;\r
12; AsmReadDr5 function\r
13;\r
14; Notes:\r
15;\r
16;------------------------------------------------------------------------------\r
17\r
18 SECTION .text\r
19\r
20;------------------------------------------------------------------------------\r
21; UINTN\r
22; EFIAPI\r
23; AsmReadDr5 (\r
24; VOID\r
25; );\r
26;------------------------------------------------------------------------------\r
27global ASM_PFX(AsmReadDr5)\r
28ASM_PFX(AsmReadDr5):\r
29 ;\r
30 ; DR5 is alias to DR7 only if DE (in CR4) is cleared. Otherwise, reading\r
31 ; this register will cause a #UD exception.\r
32 ;\r
33 ; MS assembler doesn't support this instruction since no one would use it\r
34 ; under normal circustances. Here opcode is used.\r
35 ;\r
36 DB 0xf, 0x21, 0xe8\r
37 ret\r
38\r