1 ;------------------------------------------------------------------------------
3 ; Copyright (c) 2013, Intel Corporation. All rights reserved.<BR>
4 ; This program and the accompanying materials
5 ; are licensed and made available under the terms and conditions of the BSD License
6 ; which accompanies this distribution. The full text of the license may be found at
7 ; http://opensource.org/licenses/bsd-license.php.
9 ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
10 ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
18 ; Implementation for 16-, and 32- invocations of RDRAND instruction under 32bit platform.
22 ; Visual Studio coding practices do not use inline asm since multiple compilers and
23 ; architectures are supported assembler not recognizing rdrand instruction so using DB's.
25 ;------------------------------------------------------------------------------
31 ;------------------------------------------------------------------------------
32 ; Generate a 16 bit random number
33 ; Return TRUE if Rand generated successfully, or FALSE if not
35 ; BOOLEAN EFIAPI RdRand16Step (UINT16 *Rand); ECX
36 ;------------------------------------------------------------------------------
38 ; rdrand ax ; generate a 16 bit RN into ax, CF=1 if RN generated ok, otherwise CF=0
39 db 0fh, 0c7h, 0f0h ; rdrand r16: "0f c7 /6 ModRM:r/m(w)"
40 jb rn16_ok ; jmp if CF=1
41 xor eax, eax ; reg=0 if CF=0
42 ret ; return with failure status
49 ;------------------------------------------------------------------------------
50 ; Generate a 32 bit random number
51 ; Return TRUE if Rand generated successfully, or FALSE if not
53 ; BOOLEAN EFIAPI RdRand32Step (UINT32 *Rand); ECX
54 ;------------------------------------------------------------------------------
56 ; rdrand eax ; generate a 32 bit RN into eax, CF=1 if RN generated ok, otherwise CF=0
57 db 0fh, 0c7h, 0f0h ; rdrand r32: "0f c7 /6 ModRM:r/m(w)"
58 jb rn32_ok ; jmp if CF=1
59 xor eax, eax ; reg=0 if CF=0
60 ret ; return with failure status