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54 lines
1.8 KiB
C
54 lines
1.8 KiB
C
/*
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* Copyright (C) 2018 bzt (bztsrc@github)
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*
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* Permission is hereby granted, free of charge, to any person
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* obtaining a copy of this software and associated documentation
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* files (the "Software"), to deal in the Software without
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* restriction, including without limitation the rights to use, copy,
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* modify, merge, publish, distribute, sublicense, and/or sell copies
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* of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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* DEALINGS IN THE SOFTWARE.
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*
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*/
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#include "gpio.h"
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#define RNG_CTRL ((volatile unsigned int*)(MMIO_BASE+0x00104000))
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#define RNG_STATUS ((volatile unsigned int*)(MMIO_BASE+0x00104004))
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#define RNG_DATA ((volatile unsigned int*)(MMIO_BASE+0x00104008))
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#define RNG_INT_MASK ((volatile unsigned int*)(MMIO_BASE+0x00104010))
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/**
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* Initialize the RNG
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*/
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void rand_init()
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{
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*RNG_STATUS=0x40000;
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// mask interrupt
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*RNG_INT_MASK|=1;
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// enable
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*RNG_CTRL|=1;
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// wait for gaining some entropy
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while(!((*RNG_STATUS)>>24)) asm volatile("nop");
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}
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/**
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* Return a random number between [min..max]
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*/
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unsigned int rand(unsigned int min, unsigned int max)
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{
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return *RNG_DATA % (max-min) + min;
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}
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