I was following your rng-tools idea and I’ve got this post from archlinux arm Arch Linux ARM • View topic - [SOLVED] better entropy for raspberry pi?
At the bottom of this thread they indicate an old blog post dealing with hardware random number generator “Well, that was unexpected…”: The Raspberry Pi’s Hardware Random Number Generator – We Saw a Chicken …
They are dealing with /dev/hwrng and bcm2708-rng. Would this be relevant?
Edit: edit last question.