Rust promises memory safety without garbage collection. That's why many of us dream of writing a kernel in it. After several years of building a from‑scratch operating system in Rust, I've collected the real — not theoretical — challenges that will make you question your life choices.
Here are the five hardest problems, and the pragmatic solutions that actually work.
1. The unsafe Infection: Your Core is Not Safe
The kernel's job is to manage memory, poke hardware registers, and handle interrupts. That means unsafe is not an exception — it's the norm.
The problem: A single unsafe block can corrupt state that safe code depends on. In userspace, you isolate unsafe behind a small API. In the kernel, the entire bottom layer is unsafe. A bug in the page fault handler trashes everything.
