A simple prototype to show how you can build a linux kernel module using Rust.
You need a working C toolchain, headers for the kernel you are compiling for and a (nightly) Rust toolchain with cargo-xbuild.
To compile the module, run make all from the base directory. Try it out with make test or sudo insmod build/minimod.ko
(don't forget to unload the module with sudo rmmod minimod afterwards).
The easiest way to create a kernel module in a language other than C is to write some C code that does all the basic work for initializing a kernel module (which uses C macros and/or inline functions which are hard to call via FFI) and then calls a Rust function to take over. We also include a C function to be called from Rust as an example of how to additionally use this C file as a sort of library.
This is where most of the code in a real kernel module should go. In our case, we just have a rust_main function that calls a C function.
Since we are in a #![no_std] context, we need to define some language items ourselves.
One of the biggest missing things is the print!() macro. To implement this, you could create a struct that implements
the formatting trait and use a static instance of it to define your print!() macro using the C kprintf function. You
might also want to create an allocator using krealloc and kfree to be able to use heap-allocated data types.