1 /** @file 2 AsmMwait function 3 4 Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR> 5 This program and the accompanying materials 6 are licensed and made available under the terms and conditions of the BSD License 7 which accompanies this distribution. The full text of the license may be found at 8 http://opensource.org/licenses/bsd-license.php. 9 10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 12 13 **/ 14 15 /** 16 Executes an MWAIT instruction. 17 18 Executes an MWAIT instruction with the register state specified by Eax and 19 Ecx. Returns Eax. This function is only available on IA-32 and x64. 20 21 @param RegisterEax The value to load into EAX or RAX before executing the MONITOR 22 instruction. 23 @param RegisterEcx The value to load into ECX or RCX before executing the MONITOR 24 instruction. 25 26 @return RegisterEax 27 28 **/ 29 UINTN 30 EFIAPI 31 AsmMwait ( 32 IN UINTN RegisterEax, 33 IN UINTN RegisterEcx 34 ) 35 { 36 _asm { 37 mov eax, RegisterEax 38 mov ecx, RegisterEcx 39 _emit 0x0f // mwait 40 _emit 0x01 41 _emit 0xC9 42 } 43 } 44 45
