1 /** @file 2 AsmWriteCr4 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 Writes a value to Control Register 4 (CR4). 17 18 Writes and returns a new value to CR4. This function is only available on 19 IA-32 and x64. This writes a 32-bit value on IA-32 and a 64-bit value on x64. 20 21 @param Value The value to write to CR4. 22 23 @return The value written to CR4. 24 25 **/ 26 UINTN 27 EFIAPI 28 AsmWriteCr4 ( 29 UINTN Value 30 ) 31 { 32 _asm { 33 mov eax, Value 34 _emit 0x0f // mov cr4, eax 35 _emit 0x22 36 _emit 0xE0 37 } 38 } 39 40
