/* * Copyright (c) 2013-2014 Wind River Systems, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /** * @file * @brief Non-random number generator based on x86 CPU timestamp * * 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 #include #include /** * * @brief Initialize the random number generator * * The non-random number generator does not require any initialization. * Routine is automatically invoked by the kernel during system startup. * * @return N/A */ void sys_rand32_init(void) { } /** * * @brief Get a 32 bit random number * * The non-random number generator returns values that are based off the * CPU's timestamp counter, which means that successive calls will normally * display ever-increasing values. * * @return a 32-bit number */ uint32_t sys_rand32_get(void) { return _do_read_cpu_timestamp32(); }