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

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/** @file
AsmMonitor 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.
**/
/**
Sets up a monitor buffer that is used by AsmMwait().
Executes a MONITOR instruction with the register state specified by Eax, Ecx
and Edx. Returns Eax. This function is only available on IA-32 and X64.
@param RegisterEax The value to load into EAX or RAX before executing the MONITOR
instruction.
@param RegisterEcx The value to load into ECX or RCX before executing the MONITOR
instruction.
@param RegisterEdx The value to load into EDX or RDX before executing the MONITOR
instruction.
@return RegisterEax
**/
UINTN
EFIAPI
AsmMonitor (
IN UINTN RegisterEax,
IN UINTN RegisterEcx,
IN UINTN RegisterEdx
)
{
_asm {
mov eax, RegisterEax
mov ecx, RegisterEcx
mov edx, RegisterEdx
_emit 0x0f // monitor
_emit 0x01
_emit 0xc8
}
}