eighty-six

x86 bare metal Rust thing

I'm following the intermezzOS book to get a feel about how Rust can be used for x86 kernel development. I'm particularly interested in studying the tooling involved as I heard that developers make use of Makefiles and external assembly files to build their kernels, and I feel that neither (Makefiles or external assembly files) should be necessary if one uses Cargo to build the kernel (but I might be wrong).

I have another goal: I'd love the replace rustc dependence on an external linker (usually gcc) with a lld that's embedded in rustc itself. The x86 kernel dev space is an excellent testing ground for this as its "executables" (the kernels) are free of C dependencies (libraries, startup objects, etc.). Check the lld branch for more details.

Progress

Chapter 3

I've just finished Chapter 3, and my "kernel" prints "Hello, world!" to the screen and does nothing more 🎉. Some relevant differences between my build process and intermezzOS':

# Build the kernel
$ xargo build --target x86_64

• No external assembly files. The multiboot header (multiboot_header.asm) has been fully implemented in the linker script. And boot.asm has been implemented as Rust code (src/main.rs).
• There's only a single line of assembly: asm!("hlt"), which can't be emitted using pure Rust code (AFAIK).
• core is not explicitly build. Xargo takes care of compiling it without user intervention.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.