MdePkg: Replace Opcode with the corresponding instructions.

[mirror_edk2.git] / MdePkg / Library / BaseLib / X64 / RdRand.nasm

;------------------------------------------------------------------------------\r
;\r
; Copyright (c) 2015 - 2022, Intel Corporation. All rights reserved.<BR>\r
; SPDX-License-Identifier: BSD-2-Clause-Patent\r
;\r
; Module Name:\r
;\r
;   RdRand.nasm\r
;\r
; Abstract:\r
;\r
;   Generates random number through CPU RdRand instruction under 64-bit platform.\r
;\r
; Notes:\r
;\r
;------------------------------------------------------------------------------\r
\r
    DEFAULT REL\r
    SECTION .text\r
\r
;------------------------------------------------------------------------------\r
;  Generates a 16 bit random number through RDRAND instruction.\r
;  Return TRUE if Rand generated successfully, or FALSE if not.\r
;\r
;  BOOLEAN EFIAPI InternalX86RdRand16 (UINT16 *Rand);\r
;------------------------------------------------------------------------------\r
global ASM_PFX(InternalX86RdRand16)\r
ASM_PFX(InternalX86RdRand16):\r
    rdrand eax                     ; generate a 16 bit RN into eax,\r
                                   ; CF=1 if RN generated ok, otherwise CF=0\r
    jc     rn16_ok                 ; jmp if CF=1\r
    xor    rax, rax                ; reg=0 if CF=0\r
    ret                            ; return with failure status\r
rn16_ok:\r
    mov    [rcx], ax\r
    mov    rax,  1\r
    ret\r
\r
;------------------------------------------------------------------------------\r
;  Generates a 32 bit random number through RDRAND instruction.\r
;  Return TRUE if Rand generated successfully, or FALSE if not.\r
;\r
;  BOOLEAN EFIAPI InternalX86RdRand32 (UINT32 *Rand);\r
;------------------------------------------------------------------------------\r
global ASM_PFX(InternalX86RdRand32)\r
ASM_PFX(InternalX86RdRand32):\r
    rdrand eax                     ; generate a 32 bit RN into eax,\r
                                   ; CF=1 if RN generated ok, otherwise CF=0\r
    jc     rn32_ok                 ; jmp if CF=1\r
    xor    rax, rax                ; reg=0 if CF=0\r
    ret                            ; return with failure status\r
rn32_ok:\r
    mov    [rcx], eax\r
    mov    rax,  1\r
    ret\r
\r
;------------------------------------------------------------------------------\r
;  Generates a 64 bit random number through one RDRAND instruction.\r
;  Return TRUE if Rand generated successfully, or FALSE if not.\r
;\r
;  BOOLEAN EFIAPI InternalX86RdRand64 (UINT64 *Random);\r
;------------------------------------------------------------------------------\r
global ASM_PFX(InternalX86RdRand64)\r
ASM_PFX(InternalX86RdRand64):\r
    rdrand rax                     ; generate a 64 bit RN into rax,\r
                                   ; CF=1 if RN generated ok, otherwise CF=0\r
    jc     rn64_ok                 ; jmp if CF=1\r
    xor    rax, rax                ; reg=0 if CF=0\r
    ret                            ; return with failure status\r
rn64_ok:\r
    mov    [rcx], rax\r
    mov    rax, 1\r
    ret\r
\r