audk/MdePkg/Library/BaseLib/Ia32/WriteDr4.c

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/** @file
AsmWriteDr4 function
Copyright (c) 2006 - 2008, Intel Corporation<BR>
All rights reserved. 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.
**/
/**
Writes a value to Debug Register 4 (DR4).
Writes and returns a new value to DR4. This function is only available on
IA-32 and X64. This writes a 32-bit value on IA-32 and a 64-bit value on X64.
@param Value The value to write to Dr4.
@return The value written to Debug Register 4 (DR4).
**/
UINTN
EFIAPI
AsmWriteDr4 (
IN UINTN Value
)
{
_asm {
mov eax, Value
_emit 0x0f // mov dr4, eax
_emit 0x23
_emit 0xe0
}
}