Chimera Linux: A BSD LLVM distro from scratch (FOSDEM 2023)
Channel: Igalia
Date: 2023-05-11

Chimera Linux is a new Linux distribution started in mid-2021. It's a
general-purpose operating system based on binary packages that aims to be
practical and clean, while addressing various shortcomings of an average Linux
distro. One of the things making it unique is that it's a non-GNU distribution,
utilizing a combination of userland utilities originating from FreeBSD, the
LLVM/Clang toolchain and musl libc, besides other things. On top of that, it is
not based on any existing distribution and comes with its own packaging
infrastructure and various custom software that was needed to fill in the gaps.
It's also highly portable, already supporting x86_64, POWER, AArch64 and
RISC-V, with more possibly coming. In the presentation I will cover the
progress made in the last year, as well as give a general overview of the
system and what it takes to create a distro from scratch.

The distribution follows a rolling release model and by default uses the GNOME
desktop with Wayland. The custom package building infrastructure was created
after having learned from the shortcomings of equivalent systems in other
distros, aiming to be flexible and fast, while emphasizing correctness and
allowing for fully sandboxed, unprivileged builds. The result is binary
packages/repositories for apk-tools, which Chimera uses as a frontend package
manager. The build tooling can also bring the system up from source using a
foreign musl-based distribution as a base, making it easily bootstrappable. The
resulting repositories utilize LLVM's ThinLTO for nearly all packages, and
special emphasis is also placed on security hardening (including CFI and
others). Service management is based on the Dinit suite with a custom set of
core services and is fully supervising, dependency-based and aims to provide
practical parity with systemd, while remaining lean and grokkable (and most
importantly, portable). A major aspect of the project is to also improve
software portability across the stack, improving the state of matters for both
Linux and the BSDs. We also aim to contribute code improvements back to
FreeBSD.

Most importantly, this is not any kind of dogmatic, niche effort. It's a system
that tries to be pragmatic, providing a complete package that is polished and
has well-defined defaults, while establishing its own identity and not being
like something else. We also want to establish a community that is open and
welcoming, without pointless elitism, and most importantly have fun doing all
of this.

This is a follow-up presentation to last year's FOSDEM, but I will try my best
to make it standalone and as easy to understand as possible for the general
audience. Some basic Linux administration knowledge may be necessary for some
of the information.

Slides available at https://www.slideshare.net/igalia/chimera-linux-a-bsdllvm-distro-from-scratch

(c) FOSDEM 2023
4 & 5 February 2023
https://fosdem.org/2023/schedule/event/chimera_linux/