Added nRF hardware RNG

This commit is contained in:
Mark Qvist 2025-04-13 14:45:31 +02:00
parent 16dedc72c2
commit 0a95f6f107
2 changed files with 37 additions and 4 deletions

View File

@ -94,14 +94,24 @@ void setup() {
#endif
// Seed the PRNG for CSMA R-value selection
# if MCU_VARIANT == MCU_ESP32
#if MCU_VARIANT == MCU_ESP32
// On ESP32, get the seed value from the
// hardware RNG
int seed_val = (int)esp_random();
unsigned long seed_val = (unsigned long)esp_random();
#elif MCU_VARIANT == MCU_NRF52
// On nRF, get the seed value from the
// hardware RNG
unsigned long seed_val = get_rng_seed();
#else
// Otherwise, get a pseudo-random seed
// value from an unconnected analog pin
int seed_val = analogRead(0);
//
// CAUTION! If you are implementing the
// firmware on a platform that does not
// have a hardware RNG, you MUST take
// care to get a seed value with enough
// entropy at each device reset!
unsigned long seed_val = analogRead(0);
#endif
randomSeed(seed_val);

View File

@ -18,6 +18,7 @@
#if HAS_EEPROM
#include <EEPROM.h>
#elif PLATFORM == PLATFORM_NRF52
#include <hal/nrf_rng.h>
#include <Adafruit_LittleFS.h>
#include <InternalFileSystem.h>
using namespace Adafruit_LittleFS_Namespace;
@ -103,6 +104,28 @@ uint8_t boot_vector = 0x00;
// TODO: Get NRF52 boot flags
#endif
#if MCU_VARIANT == MCU_NRF52
unsigned long get_rng_seed() {
nrf_rng_error_correction_enable(NRF_RNG);
nrf_rng_shorts_disable(NRF_RNG, NRF_RNG_SHORT_VALRDY_STOP_MASK);
nrf_rng_task_trigger(NRF_RNG, NRF_RNG_TASK_START);
while (!nrf_rng_event_check(NRF_RNG, NRF_RNG_EVENT_VALRDY));
uint8_t rb_a = nrf_rng_random_value_get(NRF_RNG);
nrf_rng_event_clear(NRF_RNG, NRF_RNG_EVENT_VALRDY);
while (!nrf_rng_event_check(NRF_RNG, NRF_RNG_EVENT_VALRDY));
uint8_t rb_b = nrf_rng_random_value_get(NRF_RNG);
nrf_rng_event_clear(NRF_RNG, NRF_RNG_EVENT_VALRDY);
while (!nrf_rng_event_check(NRF_RNG, NRF_RNG_EVENT_VALRDY));
uint8_t rb_c = nrf_rng_random_value_get(NRF_RNG);
nrf_rng_event_clear(NRF_RNG, NRF_RNG_EVENT_VALRDY);
while (!nrf_rng_event_check(NRF_RNG, NRF_RNG_EVENT_VALRDY));
uint8_t rb_d = nrf_rng_random_value_get(NRF_RNG);
nrf_rng_event_clear(NRF_RNG, NRF_RNG_EVENT_VALRDY);
nrf_rng_task_trigger(NRF_RNG, NRF_RNG_TASK_STOP);
return rb_a << 24 | rb_b << 16 | rb_c << 8 | rb_d;
}
#endif
#if HAS_NP == true
#include <Adafruit_NeoPixel.h>
#define NUMPIXELS 1
@ -349,7 +372,7 @@ void hard_reset(void) {
#elif MCU_VARIANT == MCU_ESP32
ESP.restart();
#elif MCU_VARIANT == MCU_NRF52
NVIC_SystemReset();
NVIC_SystemReset();
#endif
}