/* rand32.c - random number generator */ /* * Copyright (c) 2013-2015 Wind River Systems, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1) Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * 2) Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * 3) Neither the name of Wind River Systems nor the names of its contributors * may be used to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /* DESCRIPTION This module provides a non-random implementation of _Rand32Get(), which is not meant to be used in a final product as a truly random number generator. It was provided to allow testing of kernel stack canaries on a BSP that does not (yet) provide a random number generator. */ #include #include #if defined(CONFIG_TEST_RANDOM_GENERATOR) #if defined(__GNUC__) /******************************************************************************* * * _Rand32Init - initialize the random number generator * * The non-random number generator does not require any initialization. * * RETURNS: N/A */ void _Rand32Init(void) { } /******************************************************************************* * * _Rand32Get - 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 normally * display ever-increasing values. * * RETURNS: a 32-bit number */ uint32_t _Rand32Get(void) { return timer_read(); } #endif /* __GNUC__ */ #endif /* CONFIG_TEST_RANDOM_GENERATOR */