Linux on phones: Android, Ubuntu Touch and postmarketOS

In short: Almost every smartphone already runs Linux: Android uses the Linux kernel. “Real” Linux on the phone with familiar software exists with projects such as Ubuntu Touch and postmarketOS.

Android

Android = Linux kernel + its own system layer (ART instead of the usual libraries, its own interface). The programs differ from those of a desktop distribution. The kernel is adapted by the manufacturer and rarely updated, see The Linux kernel in overview.

Mobile Linux systems

• postmarketOS: built on Alpine Linux, long-lived, many interfaces (Phosh, Plasma Mobile, Sxmo). Runs on many older devices.
• Ubuntu Touch (UBports): touch system with its own interface (Lomiri), apps from its own store, update system with a read-only base (similar to immutable distros).
• Sailfish OS, Mobian, Droidian and more.
• Linux phones: PinePhone, Librem 5, Fairphone ports.

Where it hurts

1. Drivers: camera, modem, GPS and sensors are often proprietary, hence incomplete.
2. Apps: banking and messenger apps are missing or run only through extra layers (Waydroid for Android apps).
3. Battery: power saving is weaker.
4. Installation: unlock the bootloader, lose the warranty.

Whoever only wants to try the desktop part can test it in Trying out Linux. A small variant is Raspberry Pi with Linux.

See also: Flatpak, Snap and AppImage