circuitpython/ports/samd/moduos.c
robert-hh b110266897 samd/moduos: Add uos.urandom() using the phase-jitter rng.
This RNG passes many of the Diehard tests and also the AIS31 test suite.
The RNG is quite slow, delivering 200bytes/s.

Tested on boards with and without a crystal.
2023-02-21 23:17:44 +11:00

114 lines
3.3 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016 Damien P. George
*
* use of the TRNG by
* Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
* Copyright (c) 2019 Artur Pacholec
* Copyright (c) 2022 Robert Hammelrath
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "py/runtime.h"
#include "py/mphal.h"
#include "modmachine.h"
#include "sam.h"
#if defined(MCU_SAMD51)
static bool initialized = false;
STATIC void trng_start(void) {
if (!initialized) {
MCLK->APBCMASK.bit.TRNG_ = 1;
REG_TRNG_CTRLA = TRNG_CTRLA_ENABLE;
initialized = true;
}
}
uint32_t trng_random_u32(void) {
trng_start();
while ((REG_TRNG_INTFLAG & TRNG_INTFLAG_DATARDY) == 0) {
}
return REG_TRNG_DATA;
}
#define TRNG_RANDOM_U32 trng_random_u32()
#endif // defined(MCU_SAMD51)
#if defined(MCU_SAMD21)
extern volatile uint32_t rng_state;
uint32_t trng_random_u32(int delay) {
mp_hal_delay_ms(delay); // wait a few cycles
uint32_t upper = rng_state;
mp_hal_delay_ms(delay); // wait again a few cycles
return (upper & 0xffff0000) | (rng_state >> 16);
}
#define trng_start()
#define TRNG_RANDOM_U32 trng_random_u32(10)
#endif
#if MICROPY_PY_UOS_URANDOM
STATIC mp_obj_t mp_uos_urandom(mp_obj_t num) {
mp_int_t n = mp_obj_get_int(num);
vstr_t vstr;
vstr_init_len(&vstr, n);
uint32_t rngval = 0;
trng_start();
for (int i = 0; i < n; i++) {
if ((i % 4) == 0) {
rngval = TRNG_RANDOM_U32;
}
vstr.buf[i] = rngval & 0xff;
rngval >>= 8;
}
return mp_obj_new_bytes_from_vstr(&vstr);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(mp_uos_urandom_obj, mp_uos_urandom);
#endif // MICROPY_PY_UOS_URANDOM
#if MICROPY_PY_UOS_DUPTERM_BUILTIN_STREAM
bool mp_uos_dupterm_is_builtin_stream(mp_const_obj_t stream) {
const mp_obj_type_t *type = mp_obj_get_type(stream);
return type == &machine_uart_type;
}
#endif
#if MICROPY_PY_UOS_DUPTERM_NOTIFY
STATIC mp_obj_t mp_uos_dupterm_notify(mp_obj_t obj_in) {
(void)obj_in;
for (;;) {
int c = mp_uos_dupterm_rx_chr();
if (c < 0) {
break;
}
ringbuf_put(&stdin_ringbuf, c);
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(mp_uos_dupterm_notify_obj, mp_uos_dupterm_notify);
#endif