urngd is OpenWrt's micro non-physical true random number generator based on timing jitter.
Using the Jitter RNG core, the rngd provides an entropy source that feeds into the Linux
/dev/random device if its entropy runs low. It updates the /dev/random entropy estimator
such that the newly provided entropy unblocks /dev/random. The seeding of /dev/random also
ensures that /dev/urandom benefits from entropy. Especially during boot time, when the
entropy of Linux is low, the Jitter RNGd provides a source of sufficient entropy.