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48 lines
1.1 KiB
48 lines
1.1 KiB
/* |
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* Copyright (c) 2013-2015 Wind River Systems, Inc. |
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* |
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* SPDX-License-Identifier: Apache-2.0 |
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*/ |
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/** |
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* @file |
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* @brief Non-random number generator based on system timer |
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* |
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* This module provides a non-random implementation of sys_rand32_get(), which |
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* is not meant to be used in a final product as a truly random number |
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* generator. It was provided to allow testing on a platform that does not (yet) |
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* provide a random number generator. |
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*/ |
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#include <random/rand32.h> |
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#include <drivers/timer/system_timer.h> |
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#include <kernel.h> |
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#include <sys/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; |
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#define _RAND32_INC 1000000013 |
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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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u32_t sys_rand32_get(void) |
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{ |
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return k_cycle_get_32() + atomic_add(&_rand32_counter, _RAND32_INC); |
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} |
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#endif /* __GNUC__ */
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