116 lines
3.6 KiB
C
116 lines
3.6 KiB
C
/*
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* This file is part of the Micro Python project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2015 Daniel Campora
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies 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 included in
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* 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, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, 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 DEALINGS IN
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* THE SOFTWARE.
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*/
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#include <stdint.h>
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#include <stdbool.h>
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#include "inc/hw_types.h"
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#include "inc/hw_ints.h"
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#include "inc/hw_memmap.h"
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#include "rom_map.h"
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#include "prcm.h"
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#include "simplelink.h"
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#include "modwlan.h"
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#include "py/obj.h"
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#include "random.h"
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#include "debug.h"
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/******************************************************************************
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* LOCAL TYPES
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******************************************************************************/
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typedef union Id_t {
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uint32_t id32;
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uint16_t id16[3];
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uint8_t id8[6];
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} Id_t;
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/******************************************************************************
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* LOCAL VARIABLES
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******************************************************************************/
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static uint32_t s_seed;
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/******************************************************************************
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* LOCAL FUNCTION DECLARATIONS
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******************************************************************************/
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static uint32_t lfsr (uint32_t input);
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/******************************************************************************
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* PRIVATE FUNCTIONS
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******************************************************************************/
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static uint32_t lfsr (uint32_t input) {
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assert( input != 0 );
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/*lint -save -e501*/
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return (input >> 1) ^ (-(input & 0x01) & 0x00E10000);
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/*lint -restore*/
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}
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#if MICROPY_HW_ENABLE_RNG
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/// \moduleref rng
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/// \function rng()
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/// Return a 24-bit hardware generated random number.
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STATIC mp_obj_t pyb_rng_get(void) {
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return mp_obj_new_int(rng_get());
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}
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MP_DEFINE_CONST_FUN_OBJ_0(pyb_rng_get_obj, pyb_rng_get);
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#endif
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/******************************************************************************
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* PUBLIC FUNCTIONS
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******************************************************************************/
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void rng_init0 (void) {
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Id_t juggler;
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uint32_t seconds;
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uint16_t mseconds;
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// get the seconds and the milliseconds from the RTC
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MAP_PRCMRTCGet(&seconds, &mseconds);
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wlan_get_mac (juggler.id8);
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// Flatten the 48-bit board identification to 24 bits
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juggler.id16[0] ^= juggler.id16[2];
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juggler.id8[0] ^= juggler.id8[3];
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juggler.id8[1] ^= juggler.id8[4];
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juggler.id8[2] ^= juggler.id8[5];
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s_seed = juggler.id32 & 0x00FFFFFF;
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s_seed += (seconds & 0x000FFFFF) + mseconds;
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// The seed must not be zero
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if (s_seed == 0) {
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s_seed = 1;
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}
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}
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uint32_t rng_get (void) {
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s_seed = lfsr( s_seed );
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return s_seed;
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}
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