Rust OSDev Operating System Development in Rust

This Month in Rust OSDev: January 2025

Published on (edited by @phil-opp)

Welcome to a new issue of "This Month in Rust OSDev". In these posts, we give a regular overview of notable changes in the Rust operating system development ecosystem.

This series is openly developed on GitHub. Feel free to open pull requests there with content you would like to see in the next issue. If you find some issues on this page, please report them by creating an issue or using our comment form at the bottom of this page.

Announcements, News, and Blog Posts

Here we collect news, blog posts, etc. related to OS development in Rust.

Infrastructure and Tooling

In this section, we collect recent updates to rustc, cargo, and other tooling that are relevant to Rust OS development.

rust-osdev Projects

In this section, we give an overview of notable changes to the projects hosted under the rust-osdev organization.

uefi-rs

Maintained by @GabrielMajeri, @nicholasbishop, and @phip1611

uefi makes it easy to develop Rust software that leverages safe, convenient, and performant abstractions for UEFI functionality.

We merged the following PRs this month:

Thanks to @crawfxrd and @hannahfluch for their contributions!

bootloader

Maintained by @phil-opp and @Freax13

The bootloader crate implements a custom Rust-based bootloader for easy loading of 64-bit ELF executables. This month, we merged the following improvements:

x86_64

Maintained by @phil-opp, @josephlr, and @Freax13

The x86_64 crate provides various abstractions for x86_64 systems, including wrappers for CPU instructions, access to processor-specific registers, and abstraction types for architecture-specific structures such as page tables and descriptor tables.

We merged the following PRs this month:

Thanks to @hannahfluch and @adavis628 for their contributions!

acpi

Maintained by @IsaacWoods

The acpi repository contains crates for parsing the ACPI tables – data structures that the firmware of modern computers use to relay information about the hardware to the OS. We merged the following changes this month:

Thanks to @IsaacWoods, @mrjbom, and @00xc for their contributions!

multiboot2

Maintained by @phip1611

Convenient and safe parsing of Multiboot2 Boot Information (MBI) structures and the contained information tags. Usable in no_std environments, such as a kernel. An optional builder feature also allows the construction of the corresponding structures.

We merged the following PRs this month:

Other Projects

In this section, we describe updates to Rust OS projects that are not directly related to the rust-osdev organization. Feel free to create a pull request with the updates of your OS project for the next post.

roeeshoshani/genesis

(Section written by @roeeshoshani)

genesis is a bare metal firmware implementation for mips. it implements everything from the bottom up, from initializing the cpu caches, to configuring pci devices and the interrupt controller.

this month, the core async executor was implemented.

this means that we can implement blocking operations (for example reading a byte from the UART) as rust futures, and we then .await them.

this makes our lives much easier when writing code that needs to block until some I/O events happen. instead of using callbacks, and having to pass our state all over the place, we can just .await the blocking future, and write our code using async functions, which is much more ergonomic.

example

currently, there is only one blocking operation implemented, the operation of reading a byte from the UART.

this allows code like the following to be written:

loop {
    let byte = uart_read_byte().await;
    println!("received uart byte: {}", byte);
}

which is a huge improvement over the previous implementation of putting the code inside the UART interrupt handler.

how does it work?

the way this works is that the core kernel's main loop looks roughly like the following:

loop {
    poll_tasks();
    wait_for_interrupt();
}

then, the interrupt handler is responsible for waking up the relevant tasks.

futures that need interrupt handlers to wake them up should somehow register themselves, and the interrupt hanlers will then wake the registered tasks.

then, in the next iteration, the tasks that were woken up will be polled again, which completes the loop.

Join Us?

Are you interested in Rust-based operating system development? Our rust-osdev organization is always open to new members and new projects. Just let us know if you want to join! A good way for getting in touch is our Zulip chat.

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