void hwrng_read(void *buf, unsigned int num)
{
unsigned int count = 0;
uint8_t *b = (uint8_t *)buf;
/* power on and enable the device */
HWRNG_CLKEN();
KINETIS_RNGA->CR = RNG_CR_INTM_MASK | RNG_CR_HA_MASK | RNG_CR_GO_MASK;
/* self-seeding */
while (!(KINETIS_RNGA->SR & RNG_SR_OREG_LVL_MASK));
KINETIS_RNGA->ER = KINETIS_RNGA->OR ^ (uint32_t)buf;
while (count < num) {
/* wait for random data to be ready to read */
while (!(KINETIS_RNGA->SR & RNG_SR_OREG_LVL_MASK));
uint32_t tmp = KINETIS_RNGA->OR;
/* copy data into result vector */
for (int i = 0; i < 4 && count < num; i++) {
b[count++] = (uint8_t)tmp;
tmp = tmp >> 8;
}
}
/* power off the device */
KINETIS_RNGA->CR = 0;
HWRNG_CLKDIS();
}
void hwrng_read(void *buf, unsigned int num)
{
unsigned int count = 0;
uint8_t *b = (uint8_t *)buf;
HWRNG_CLKEN();
if ((KINETIS_RNGB->VER & RNG_VER_TYPE_MASK) != 0b0001) {
/* Wrong type of RNG */
/* TODO: Handle */
}
/* Software reset, bit is self-clearing */
BITBAND_REG32(KINETIS_RNGB->CMD, RNG_CMD_SR_SHIFT) = 1;
/* Set up automatic reseed */
KINETIS_RNGB->CR = RNG_CR_AR_MASK | RNG_CR_MASKERR_MASK | RNG_CR_MASKDONE_MASK;
while (count < num) {
uint32_t tmp;
/* wait for random data to be ready to read */
while (!(KINETIS_RNGB->SR & RNG_SR_FIFO_LVL_MASK));
tmp = KINETIS_RNGB->OUT;
/* copy data into result vector */
for (int i = 0; i < 4 && count < num; i++) {
b[count++] = (uint8_t)tmp;
tmp = tmp >> 8;
}
}
KINETIS_RNGB->CR = 0;
HWRNG_CLKDIS();
}
