Booting to Rust
A couple nights ago I was looking over the UEFI spec, and I realized it shouldn’t be too hard to write UEFI applications in Rust. It turns out, you can, and here I will tell you how.
The thing that surprises me most about UEFI is that it now appears possible to boot your machine without ever writing a single line of assembly language. Booting used to require this tedious process of starting out in 16-bit real mode, then transitioning into 32-bit protected mode and then doing it all over again to get into 64-bit mode. UEFI firmwares, on the other hand, will happily load an executable file that you give it and run your code in 64-bit mode from the start. Your startup function receives a pointer to some functions that give you basic console support, as well as an API to access richer features. From a productivity standpoint, this seems like a win, but I also miss the sorcery you used to have to do when you were programming at this level.
Booting to Rust is a lot like writing bindings to any C library, except that the linking process is a bit more involved.
