Phill's blog series is the best there is for kernel Rust. Glad to see another installment!

Note that in Rust today we can only use standard collection with the global allocator. https://github.com/phil-opp/blog_os/blob/post-10/src/main.rs... in the blog post it is intialized, and there's nothing to prevent allocation earlier and that will fail.

But there is work in progress (first https://github.com/rust-lang/rust/pull/58457) that will allow using local allocators, removing the ambient authority that makes that failure possible. Note that this doesn't mean a runtime cost. One can pass around a zero-sized token that is completely erased.