1 #------------------------------------------------------------------------------ ; 2 # Copyright (c) 2015 - 2016, Intel Corporation. All rights reserved.<BR> 3 # This program and the accompanying materials 4 # are licensed and made available under the terms and conditions of the BSD License 5 # which accompanies this distribution. The full text of the license may be found at 6 # http://opensource.org/licenses/bsd-license.php. 7 # 8 # THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 9 # WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 10 # 11 # Module Name: 12 # 13 # RdRand.S 14 # 15 # Abstract: 16 # 17 # Generates random number through CPU RdRand instruction under 64-bit platform. 18 # 19 # Notes: 20 # 21 #------------------------------------------------------------------------------ 22 23 //------------------------------------------------------------------------------ 24 // Generates a 16 bit random number through RDRAND instruction. 25 // Return TRUE if Rand generated successfully, or FALSE if not. 26 // 27 // BOOLEAN EFIAPI InternalX86RdRand16 (UINT16 *Rand); 28 //------------------------------------------------------------------------------ 29 ASM_GLOBAL ASM_PFX(InternalX86RdRand16) 30 ASM_PFX(InternalX86RdRand16): 31 .byte 0x0f, 0xc7, 0xf0 // rdrand r16: "0f c7 /6 ModRM:r/m(w)" 32 jc rn16_ok // jmp if CF=1 33 xor %rax, %rax // reg=0 if CF=0 34 ret // return with failure status 35 rn16_ok: 36 mov %ax, (%rcx) 37 mov $0x1, %rax 38 ret 39 40 //------------------------------------------------------------------------------ 41 // Generates a 32 bit random number through RDRAND instruction. 42 // Return TRUE if Rand generated successfully, or FALSE if not. 43 // 44 // BOOLEAN EFIAPI InternalX86RdRand32 (UINT32 *Rand); 45 //------------------------------------------------------------------------------ 46 ASM_GLOBAL ASM_PFX(InternalX86RdRand32) 47 ASM_PFX(InternalX86RdRand32): 48 .byte 0x0f, 0xc7, 0xf0 // rdrand r32: "0f c7 /6 ModRM:r/m(w)" 49 jc rn32_ok // jmp if CF=1 50 xor %rax, %rax // reg=0 if CF=0 51 ret // return with failure status 52 rn32_ok: 53 mov %eax, (%rcx) 54 mov $0x1, %rax 55 ret 56 57 //------------------------------------------------------------------------------ 58 // Generates a 64 bit random number through RDRAND instruction. 59 // Return TRUE if Rand generated successfully, or FALSE if not. 60 // 61 // BOOLEAN EFIAPI InternalX86RdRand64 (UINT64 *Rand); 62 //------------------------------------------------------------------------------ 63 ASM_GLOBAL ASM_PFX(InternalX86RdRand64) 64 ASM_PFX(InternalX86RdRand64): 65 .byte 0x48, 0x0f, 0xc7, 0xf0 // rdrand r64: "REX.W + 0f c7 /6 ModRM:r/m(w)" 66 jc rn64_ok // jmp if CF=1 67 xor %rax, %rax // reg=0 if CF=0 68 ret // return with failure status 69 rn64_ok: 70 mov %rax, (%rcx) 71 mov $0x1, %rax 72 ret 73
