Contiki-NG
random-arch.c
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1/*
2 * Copyright (c) 2020, Toshiba BRIL
3 * Copyright (C) 2020 Yago Fontoura do Rosario <yago.rosario@hotmail.com.br>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the copyright holder nor the names of its
15 * contributors may be used to endorse or promote products derived
16 * from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
22 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
25 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
27 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
29 * OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31/*---------------------------------------------------------------------------*/
32/**
33 * \addtogroup nrf
34 * @{
35 *
36 * \addtogroup nrf-os OS drivers
37 * @{
38 *
39 * \addtogroup nrf-random Random driver
40 * @{
41 *
42 * \file
43 * Random driver for the nRF.
44 * \author
45 * Yago Fontoura do Rosario <yago.rosario@hotmail.com.br>
46 *
47 */
48/*---------------------------------------------------------------------------*/
49#include <stdlib.h>
50
51#include "nrfx.h"
52
53/*---------------------------------------------------------------------------*/
54/**
55 * @brief Generates a new random number
56 * @return The random number.
57 */
58unsigned short
59random_rand(void)
60{
61 return (unsigned short)rand();
62}
63/*---------------------------------------------------------------------------*/
64/**
65 * @brief Initialize the random number generator
66 * @param seed Ignored if NRF_RNG is present.
67 */
68void
69random_init(unsigned short seed)
70{
71/* If board supports RNG uses it to seed srand */
72#ifdef NRF_RNG
73 (void)seed;
74
75 unsigned short hwrng = 0;
76 NRF_RNG->TASKS_START = 1;
77
78 NRF_RNG->EVENTS_VALRDY = 0;
79 while(!NRF_RNG->EVENTS_VALRDY);
80 hwrng = (NRF_RNG->VALUE & 0xFF);
81
82 NRF_RNG->EVENTS_VALRDY = 0;
83 while(!NRF_RNG->EVENTS_VALRDY);
84 hwrng |= ((NRF_RNG->VALUE & 0xFF) << 8);
85
86 NRF_RNG->TASKS_STOP = 1;
87
88 srand(hwrng);
89#else /* NRF_RNG */
90 srand(seed);
91#endif /* NRF_RNG */
92}
93/*---------------------------------------------------------------------------*/
94/**
95 * @}
96 * @}
97 * @}
98 */
random_init
void random_init(unsigned short seed)
Initialize the random number generator.
Definition: random-arch.c:70
random_rand
unsigned short random_rand(void)
Generates a new random number.
Definition: random-arch.c:60