RPis don't necessarily have RDRAND, they especially suffer from increasingly fast boot where waiting for the entropy pool is an actual concern. Of course, not

RPis don't necessarily have RDRAND, they especially suffer from increasingly fast boot where waiting for the entropy pool is an actual concern. Of course, not all applications need that kind of cryptographic entropy but during early boot it's pretty much the best randomness you can get (seeding from datetime isn't available on the RPi, so until you can bring up the network and contact the NTP server, you're stuck with whatever getrandom() returns)