Rust OSDev Operating System Development in Rust

This Month in Rust OSDev: March 2023

Published on (edited by @phil-opp and @phip1611)

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.

Infrastructure and Tooling

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

Announcements, News, and Blog Posts

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

rust-osdev Projects

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

multiboot2

Maintained by @IsaacWoods, @phip1611, @robert-w-gries, @ahmedcharles, and @Caduser2020

The multiboot2 crate provides abstraction types for the multiboot information structure (MBI) of multiboot2 bootloaders. The latest release of the multiboot2-crate is now v0.15.0 (was v0.14.0), which fixed a bug. Furthermore, the documentation was improved. However, the biggest change is that the library now allows the parsing of custom multiboot tags, which are not prohibited by the spec. For a full changelog, please refer to the GitHub repo.

CI Refactoring

In the CI, we want to run many tests that cover a big portion of the cartesian product of the following properties:

  • rust version: stable, nightly, msrv
  • type: build, test, style check
  • target: default, no_std

As I (@phip1611) was annoyed by all the boilerplate configuration and repetition, I've investigated new ways to improve that situation and created a reusable workflow can be used like that:

jobs:
  build_msrv:
    name: build (msrv)
    uses: ./.github/workflows/_build-rust.yml
    with:
      rust-version: 1.56.1
      do-style-check: false

  style_nightly:
    name: style (nightly)
    needs: build_nightly
    uses: ./.github/workflows/_build-rust.yml
    with:
      rust-version: nightly
      do-style-check: true
      do-test: false

The ./.github/workflows/_build-rust.yml workflow abstracts setting up the toolchain, setting up a cargo cache for a faster CI, and, depending on the configuration, running cargo test|clippy|doc|build|fmt. I think that the outcome is quite nice and might also help others. Feel free to check out the corresponding PR.

uefi-rs

Maintained by @GabrielMajeri, @nicholasbishop, and @phip1611

Features

Other Improvements

Docs

CI & Testing

show changes

Dependencies

show changes

    Thanks to @hughsie, @nicholasbishop, @JohnAZoidberg, @phip1611, @JarlEvanson, and @dependabot[bot] for their contributions!

    x86_64

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

    Thanks to @joycebrum for their contributions!

    acpi

    Maintained by @IsaacWoods

    Thanks to @A0lson, @rcerc, and @rw-vanc for their contributions!

    pci_types

    Maintained by @IsaacWoods

    Thanks to @devsnek for their contributions!

    bootloader

    Maintained by @phil-opp

    Thanks to @jasoncouture for their contributions!

    vga

    Maintained by @RKennedy9064

    Thanks to @bendudson for their contributions!

    pic8259

    Maintained by @phil-opp

    Thanks to @Virux for their contributions!

    volatile

    Maintained by @phil-opp

    Thanks to @joycebrum for their contributions!

    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.

    phip1611/paging-calculator

    (Section written by @phip1611)

    In the November newsletter, I announced the initial release of my paging-calculator CLI utility. Recently, I released a new version, which now covers page table indices for x86, x86 with physical address extension (PAE), x86_64, and x86_64 with 5 levels. For example, just type $ paging-calculator 0xdeadbeef x86 and $ paging-calculator 0xdeadbeef x86 --paeand compare the result. You can install it from crates.io or with the pkgs.paging-calculator attribute, if you are a Nix user.

    Screenshot: Paging Calculator CLI Utility

    xiaoyang-sde/rust-kernel-riscv

    (Section written by @xiaoyang-sde)

    rust-kernel-riscv is an experimental operating system kernel built using Rust's asynchronous programming model to schedule threads in both kernel and user space. This approach allows for more efficient context switching and eliminates the need for allocating a separate kernel stack for each user process. In its current iteration, the kernel provides a basic shell capable of running several executables that demonstrate various kernel mechanisms.

    The kernel provides a built-in executor, which manages the scheduling and execution of threads. Threads are executed for a time slice before an exception or interrupt occurs, and then the executor switches to another thread. To give you a better understanding, I included the async function that represents the lifetime of a user thread below, and I wrote a detailed design document.

    async fn thread_loop(thread: Arc<Thread>) {
    loop {
        let trap_context = thread.state().lock().user_trap_context_mut();
        _enter_user_space(trap_context, thread.satp());

        // Invokes related methods to handle the exception or interrupt,
        // which returns a variant of the `ControlFlow` enum

        match control_flow {
            ControlFlow::Continue => continue,
            ControlFlow::Yield => yield_now().await,
            ControlFlow::Exit(exit_code) => {
                thread.exit(exit_code);
                break;
            }
        }
    }
}

    The idea behind rust-kernel-riscv was inspired by Phil's recent blog post on using async/await in the kernel. Thanks Phil for his invaluable support to the Rust community!

    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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