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56 lines
1.1 KiB
C
56 lines
1.1 KiB
C
/*
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* Copyright (C) 2019 Gunar Schorcht
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*
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* This file is subject to the terms and conditions of the GNU Lesser
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* General Public License v2.1. See the file LICENSE in the top level
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* directory for more details.
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*/
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/**
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* @ingroup cpu_esp8266
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* @ingroup drivers_periph_hwrng
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* @{
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*
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* @file
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* @brief Low-level random number generator driver implementation for ESP8266 SoCs
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*
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* @author Gunar Schorcht <gunar@schorcht.net>
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*
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* @}
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*/
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#include "cpu.h"
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#include "periph_conf.h"
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#include "periph/hwrng.h"
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#define RNG_DATA_REG (*(volatile uint32_t *)RNG_DATA_REG_ADDR)
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void hwrng_init(void)
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{
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/* no need for initialization */
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}
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void hwrng_read(void *buf, unsigned int num)
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{
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unsigned int count = 0;
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uint8_t *b = (uint8_t *)buf;
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while (count < num) {
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/* read next 4 bytes of random data */
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uint32_t tmp = RNG_DATA_REG;
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/* copy data into result vector */
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for (int i = 0; i < 4 && count < num; i++) {
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b[count++] = (uint8_t)tmp;
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tmp = tmp >> 8;
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}
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}
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}
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uint32_t hwrand(void)
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{
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uint32_t _tmp;
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hwrng_read(&_tmp, sizeof(uint32_t));
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return _tmp;
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}
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