[anonymous_sorry]

Kernels and device drivers have to read and write from hardware registers. Doing so is fundamentally "unsafe", by Rust's definition. Hardware is a big bag of external state which can often be mutated external to any software running on the CPU. It's a device driver's job to abstract away this unsafe interface and (ideally) try to present a safe one.

That's not to say there aren't benefits to using languages other than C for this stuff. But a Rust kernel will necessarily rely on `unsafe` blocks to do its job.