blob: 76bd228288cf95a8f1d302e0f44f026fc9728ecd [file] [log] [blame]
/*
* Copyright (c) 2013-2015 Wind River Systems, Inc.
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
* @brief Non-random number generator based on system timer
*
* This module provides a non-random implementation of sys_rand32_get(), which
* is not meant to be used in a final product as a truly random number
* generator. It was provided to allow testing on a platform that does not (yet)
* provide a random number generator.
*/
#include <random/rand32.h>
#include <drivers/timer/system_timer.h>
#include <kernel.h>
#include <sys/atomic.h>
#if defined(__GNUC__)
/*
* Symbols used to ensure a rapid series of calls to random number generator
* return different values.
*/
static atomic_val_t _rand32_counter;
#define _RAND32_INC 1000000013
/**
*
* @brief Get a 32 bit random number
*
* The non-random number generator returns values that are based off the
* target's clock counter, which means that successive calls will return
* different values.
*
* @return a 32-bit number
*/
u32_t sys_rand32_get(void)
{
return k_cycle_get_32() + atomic_add(&_rand32_counter, _RAND32_INC);
}
#endif /* __GNUC__ */