Inboot.s, it says "Abort if the frequency read back as 0." I wonder why? Why would it be zero? Damaged / malfunctioning hardware? And if it is zero, why not boot the Rust code and have the Rust code check if it's zero, and display a text error instead of a parking loop? I would assume that in the case that it is 0, it's better to have a readable error message than being confused about why nothing is happening.