Ubuntu Core 26 cuts OTA update size, enables ARM64 Livepatch

Canonical has released Ubuntu Core 26, a new long-term support (LTS) version of its immutable, snap-based OS.

Ubuntu Core 26 reduces over-the-air update sizes by up to 90% for most snaps through a new snap-delta format. Updates to the Core base snaps specifically drop from 16MB to 1.5MB.

Installation times also improve, with the new initramfs-based installer skips redundant reboots during provisioning. The update also enables live kernel patching on ARM64 devices so that critical and high vulnerability kernel patches get applied without needing to reboot¹.

A new Chisel-based build system is used to assemble base snaps. Explicit, traceable dependencies mean every file can be attributed to its originating package ‘slice’. As an upside, this also trims the base image size by 7%.

Ubuntu Frame (the display server Ubuntu Core uses to run GUI apps on kiosk and embedded devices) can now support multiple apps on a single screen with configurable layouts. A new gpu-2604 snap interface gives those apps access to GPU acceleration.

Ubuntu Core 26 also includes:

• Snapcraft components to ship large or optional resources separately
• Native OP-TEE integration for ARM TrustZone hardware-rooted key protection
• TPM-sealed keys stored in the LUKS2 header
• EU Cyber Resilience Act compliance
• Logs and metrics can stream to Grafana, Loki and Prometheus

Ubuntu Core 26 is available to download now, with more details available on the the Canonical blog.

As a reminder, Ubuntu Core is not a full-fat desktop OS (though an Ubuntu Core Desktop is in development but remains a WIP). It’s a minimal, Snap-based version of the distro that’s designed for use in embedded IoT, robotics and edge computing scenarios.

1. Livepatch is also enabled for AMD64-based devices in Ubuntu Core 20 and up, nice! ↩︎