| ;------------------------------------------------------------------------------ | |
| ; | |
| ; Copyright (c) 2006 - 2022, Intel Corporation. All rights reserved.<BR> | |
| ; SPDX-License-Identifier: BSD-2-Clause-Patent | |
| ; | |
| ; Module Name: | |
| ; | |
| ; ReadDr4.Asm | |
| ; | |
| ; Abstract: | |
| ; | |
| ; AsmReadDr4 function | |
| ; | |
| ; Notes: | |
| ; | |
| ;------------------------------------------------------------------------------ | |
| SECTION .text | |
| ;------------------------------------------------------------------------------ | |
| ; UINTN | |
| ; EFIAPI | |
| ; AsmReadDr4 ( | |
| ; VOID | |
| ; ); | |
| ;------------------------------------------------------------------------------ | |
| global ASM_PFX(AsmReadDr4) | |
| ASM_PFX(AsmReadDr4): | |
| ; | |
| ; DR4 is alias to DR6 only if DE (in CR4) is cleared. Otherwise, reading | |
| ; this register will cause a #UD exception. | |
| ; | |
| ; MS assembler doesn't support this instruction since no one would use it | |
| ; under normal circustances. | |
| ; | |
| mov eax, dr4 | |
| ret | |