f7fffae8aa
Change all the Intel and Wind River code license from BSD-3 to Apache 2. Change-Id: Id8be2c1c161a06ea8a0b9f38e17660e11dbb384b Signed-off-by: Javier B Perez Hernandez <javier.b.perez.hernandez@linux.intel.com> Signed-off-by: Anas Nashif <anas.nashif@intel.com> Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
75 lines
1.9 KiB
C
75 lines
1.9 KiB
C
/* non-random number generator based on system timer */
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/*
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* Copyright (c) 2013-2015 Wind River Systems, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/*
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DESCRIPTION
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This module provides a non-random implementation of sys_rand32_get(), which is
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not meant to be used in a final product as a truly random number generator. It
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was provided to allow testing on a platform that does not (yet) provide a
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random number generator.
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*/
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#include <drivers/rand32.h>
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#include <drivers/system_timer.h>
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#include <nanokernel.h>
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#include <atomic.h>
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#if defined(__GNUC__)
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/*
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* Symbols used to ensure a rapid series of calls to random number generator
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* return different values.
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*/
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static atomic_val_t _rand32_counter = 0;
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#define _RAND32_INC 1000000013
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/**
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*
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* @brief Initialize the random number generator
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*
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* The non-random number generator does not require any initialization.
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* This routine is automatically invoked by the kernel during system
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* initialization.
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*
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* @return N/A
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*/
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void sys_rand32_init(void)
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{
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}
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/**
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*
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* @brief Get a 32 bit random number
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*
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* The non-random number generator returns values that are based off the
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* target's clock counter, which means that successive calls will return
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* different values.
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*
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* @return a 32-bit number
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*/
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uint32_t sys_rand32_get(void)
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{
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return _sys_clock_cycle_get() + atomic_add(&_rand32_counter, _RAND32_INC);
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}
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#endif /* __GNUC__ */
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