Vipin Ranka / MGAS_GR_Peach

This is the final version of Mini Gateway for Automation and Security desgined for Renesas GR Peach Design Contest

Dependencies:   GR-PEACH_video GraphicsFramework HTTPServer R_BSP mbed-rpc mbed-rtos Socket lwip-eth lwip-sys lwip FATFileSystem

Fork of mbed-os-example-mbed5-blinky by mbed-os-examples

mbed-dev/targets/TARGET_STM/trng_api.c@12:9a20164dcc47, 2017-01-11 (annotated)

Committer:
vipinranka
Date:
Wed Jan 11 11:41:30 2017 +0000
Revision:
12:9a20164dcc47
This is the final version MGAS Project for Renesas GR Peach Design Contest

Who changed what in which revision?

UserRevisionLine numberNew contents of line
vipinranka 12:9a20164dcc47 1 /*
vipinranka 12:9a20164dcc47 2 * Hardware entropy collector for the STM32 families
vipinranka 12:9a20164dcc47 3 *
vipinranka 12:9a20164dcc47 4 * Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
vipinranka 12:9a20164dcc47 5 * SPDX-License-Identifier: Apache-2.0
vipinranka 12:9a20164dcc47 6 *
vipinranka 12:9a20164dcc47 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
vipinranka 12:9a20164dcc47 8 * not use this file except in compliance with the License.
vipinranka 12:9a20164dcc47 9 * You may obtain a copy of the License at
vipinranka 12:9a20164dcc47 10 *
vipinranka 12:9a20164dcc47 11 * http://www.apache.org/licenses/LICENSE-2.0
vipinranka 12:9a20164dcc47 12 *
vipinranka 12:9a20164dcc47 13 * Unless required by applicable law or agreed to in writing, software
vipinranka 12:9a20164dcc47 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
vipinranka 12:9a20164dcc47 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
vipinranka 12:9a20164dcc47 16 * See the License for the specific language governing permissions and
vipinranka 12:9a20164dcc47 17 * limitations under the License.
vipinranka 12:9a20164dcc47 18 *
vipinranka 12:9a20164dcc47 19 */
vipinranka 12:9a20164dcc47 20
vipinranka 12:9a20164dcc47 21 #if defined(DEVICE_TRNG)
vipinranka 12:9a20164dcc47 22
vipinranka 12:9a20164dcc47 23 #include <stdlib.h>
vipinranka 12:9a20164dcc47 24 #include "cmsis.h"
vipinranka 12:9a20164dcc47 25 #include "trng_api.h"
vipinranka 12:9a20164dcc47 26
vipinranka 12:9a20164dcc47 27 /** trng_get_byte
vipinranka 12:9a20164dcc47 28 * @brief Get one byte of entropy from the RNG, assuming it is up and running.
vipinranka 12:9a20164dcc47 29 * @param obj TRNG obj
vipinranka 12:9a20164dcc47 30 * @param pointer to the hardware generated random byte.
vipinranka 12:9a20164dcc47 31 */
vipinranka 12:9a20164dcc47 32 static void trng_get_byte(trng_t *obj, unsigned char *byte )
vipinranka 12:9a20164dcc47 33 {
vipinranka 12:9a20164dcc47 34 *byte = (unsigned char)HAL_RNG_GetRandomNumber(&obj->handle);
vipinranka 12:9a20164dcc47 35 }
vipinranka 12:9a20164dcc47 36
vipinranka 12:9a20164dcc47 37 void trng_init(trng_t *obj)
vipinranka 12:9a20164dcc47 38 {
vipinranka 12:9a20164dcc47 39 #if defined(TARGET_STM32L4)
vipinranka 12:9a20164dcc47 40 RCC_PeriphCLKInitTypeDef PeriphClkInitStruct;
vipinranka 12:9a20164dcc47 41
vipinranka 12:9a20164dcc47 42 /*Select PLLQ output as RNG clock source */
vipinranka 12:9a20164dcc47 43 PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_RNG;
vipinranka 12:9a20164dcc47 44 PeriphClkInitStruct.RngClockSelection = RCC_RNGCLKSOURCE_PLL;
vipinranka 12:9a20164dcc47 45 HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct);
vipinranka 12:9a20164dcc47 46 #endif
vipinranka 12:9a20164dcc47 47
vipinranka 12:9a20164dcc47 48 /* RNG Peripheral clock enable */
vipinranka 12:9a20164dcc47 49 __HAL_RCC_RNG_CLK_ENABLE();
vipinranka 12:9a20164dcc47 50
vipinranka 12:9a20164dcc47 51 /* Initialize RNG instance */
vipinranka 12:9a20164dcc47 52 obj->handle.Instance = RNG;
vipinranka 12:9a20164dcc47 53 HAL_RNG_Init(&obj->handle);
vipinranka 12:9a20164dcc47 54
vipinranka 12:9a20164dcc47 55 /* first random number generated after setting the RNGEN bit should not be used */
vipinranka 12:9a20164dcc47 56 HAL_RNG_GetRandomNumber(&obj->handle);
vipinranka 12:9a20164dcc47 57
vipinranka 12:9a20164dcc47 58 }
vipinranka 12:9a20164dcc47 59
vipinranka 12:9a20164dcc47 60 void trng_free(trng_t *obj)
vipinranka 12:9a20164dcc47 61 {
vipinranka 12:9a20164dcc47 62 /*Disable the RNG peripheral */
vipinranka 12:9a20164dcc47 63 HAL_RNG_DeInit(&obj->handle);
vipinranka 12:9a20164dcc47 64 /* RNG Peripheral clock disable - assume we're the only users of RNG */
vipinranka 12:9a20164dcc47 65 __HAL_RCC_RNG_CLK_DISABLE();
vipinranka 12:9a20164dcc47 66 }
vipinranka 12:9a20164dcc47 67
vipinranka 12:9a20164dcc47 68 int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length)
vipinranka 12:9a20164dcc47 69 {
vipinranka 12:9a20164dcc47 70 int ret;
vipinranka 12:9a20164dcc47 71
vipinranka 12:9a20164dcc47 72 /* Get Random byte */
vipinranka 12:9a20164dcc47 73 for( uint32_t i = 0; i < length; i++ ){
vipinranka 12:9a20164dcc47 74 trng_get_byte(obj, output + i );
vipinranka 12:9a20164dcc47 75 }
vipinranka 12:9a20164dcc47 76
vipinranka 12:9a20164dcc47 77 *output_length = length;
vipinranka 12:9a20164dcc47 78 /* Just be extra sure that we didn't do it wrong */
vipinranka 12:9a20164dcc47 79 if( ( __HAL_RNG_GET_FLAG(&obj->handle, (RNG_FLAG_CECS | RNG_FLAG_SECS)) ) != 0 ) {
vipinranka 12:9a20164dcc47 80 ret = -1;
vipinranka 12:9a20164dcc47 81 } else {
vipinranka 12:9a20164dcc47 82 ret = 0;
vipinranka 12:9a20164dcc47 83 }
vipinranka 12:9a20164dcc47 84
vipinranka 12:9a20164dcc47 85 return( ret );
vipinranka 12:9a20164dcc47 86 }
vipinranka 12:9a20164dcc47 87
vipinranka 12:9a20164dcc47 88 #endif