Cyclop OS · Kernel

linux-cyclop, a kernel tuned for the desktop

A Linux 7.3.1 kernel built from the kernel.org release, with a set of desktop patches, compiled with Clang, signed for Secure Boot. The Ubuntu kernel stays installed next to it as a fallback.

Arrives with Patch 3

Where it stands

Built, signed and in daily use on our own machines. Not in the public repository yet.

Version: 7.3.1-cyclop1
Base: Linux 7.3.1 from kernel.org, signature and SHA-256 checked, keys pinned
Repository: community, the free base every edition builds on
Availability: With Patch 3. Until then nothing changes on your machine.
Licence: GPL-2.0

It has been checked in a virtual machine with Secure Boot on, and runs on our main workstation with the NVIDIA 595 open driver. Signed modules for older NVIDIA drivers (580 and 470) are not built yet; if your machine needs one of those, keep the Ubuntu kernel, which stays in the boot menu.

What it changes

Everything else comes from the Ubuntu configuration, so AppArmor, BTF and DKMS modules keep working.

158 patches on top of 7.3.1: the BORE scheduler, desktop tuning grouped under one CONFIG_CYCLOP option, and hardware fixes. Each one is listed with its origin in docs/PATCHES.md.
Compiled with Clang, ThinLTO and -O3.
Full preemption, so the desktop keeps answering while the machine is busy.
Transparent huge pages always on.
BBRv3 congestion control available. The default stays cubic.
sched_ext built in, for schedulers loaded at run time.
No telemetry of any kind added.

Two flavours

The package picks the right one for your processor.

linux-cyclop-x64v3: For processors with AVX2 (x86-64-v3). Refuses to install on a processor that lacks it.
linux-cyclop-generic: For every other 64-bit PC.

Does your processor support x86-64-v3?

/lib64/ld-linux-x86-64.so.2 --help | grep x86-64-v3

If the line says "supported", the x64v3 flavour fits.

Secure Boot

Signed with the Cyclop Secure Boot key. Modules are signed too.

With Secure Boot on, the kernel runs in lockdown integrity mode. The firmware has to trust the Cyclop key once; after that, every update boots without a prompt.

Enrol the Cyclop key (once, after installing)

sudo mokutil --import /usr/share/linux-cyclop/7.3.1-cyclop1-x64v3/cyclop-secureboot.der

You choose a one-time password, then confirm it in the blue screen at the next start.

Which kernel is running

uname -r

The Cyclop kernel shows 7.3.1-cyclop1-x64v3 or 7.3.1-cyclop1-generic.

Source and rebuild

The whole build is public. Everything runs in a rootless podman container.

Rebuild it yourself

git clone https://git.cyclop-tech.com/packages/system-and-infrastructure/linux-cyclop.git
cd linux-cyclop
make image
make fetch
make config FLAVOR=x64v3
make build FLAVOR=x64v3
make package FLAVOR=x64v3

Signing for Secure Boot needs our private key, so a build of your own is unsigned.

Credits: the BORE scheduler by Masahito Suzuki, BBRv3 by Google ported by Oleksandr Natalenko, lockdown patches by David Howells and others, Apple T2 support from the t2linux project, and community kernel patch sets credited one by one in the patch list.

Measured before it is claimed

The kernel will not come with a speed promise. The method we use to compare it is public, the results come with Patch 3.

See the method Patch notes