uint32_t hw_rand(void)
{
uint32_t rng;
#ifdef FREESCALE_KSDK_BM
TRNG_GetRandomData(TRNG0, &rng, sizeof(rng));
#else
while((RNG->SR & RNG_SR_OREG_LVL(0xF)) == 0) {}; /* Wait until FIFO has a value available */
rng = RNG->OR; /* Return next value in FIFO output register */
#endif
return rng;
}
ssize_t hwGetentropy(void *__buffer, const size_t __length)
{
SIM_SCGC6 |= SIM_SCGC6_RNGA; // enable RNG
RNG_CR &= ~RNG_CR_SLP_MASK;
RNG_CR |= RNG_CR_HA_MASK; //high assurance, not needed
size_t pos = 0;
while (pos < __length) {
RNG_CR |= RNG_CR_GO_MASK;
while (!(RNG_SR & RNG_SR_OREG_LVL(0xF)));
const uint32_t rndVar = RNG_OR;
const uint8_t bsize = (__length - pos) > sizeof(rndVar) ? sizeof(rndVar) : (__length - pos);
(void)memcpy((uint8_t*)__buffer + pos, &rndVar, bsize);
pos += bsize;
}
SIM_SCGC6 &= ~SIM_SCGC6_RNGA; // disable RNG
return pos;
}
uint32_t hw_rand(void)
{
while((RNG->SR & RNG_SR_OREG_LVL(0xF)) == 0) {}; /* Wait until FIFO has a value available */
return RNG->OR; /* Return next value in FIFO output register */
}
