So far, almost all mobile phones capable of functioning with close-to-mainline Linux kernels (with the exception of special phones such as the PinePhone) are based on Qualcomm SoCs. Unisoc is an alternative SoC manufacturer from China that is often overlooked due to its focus on the low-end segment and lack of upstream kernel support for important features.

In 2024, Jolla released the C2 community phone as a new reference device for Sailfish OS, based on the low-end Reeder S19 Max Pro S from Turkey. This phone uses the Unisoc UMS9230 (Tiger T606 / T7200) SoC. A bit more than a year has passed since the phone was first released and the official port still uses libhybris. Meanwhile, I have been working on an unofficial mainline Linux port and am daily-driving it now. Some things are still not working, but there has been a lot of progress since the last FOSDEM.

This talk is going to explore the challenges involved in porting mainline Linux to a new SoC platform, the features I have implemented so far, and the opportunities this creates for Sailfish OS and other mobile Linux projects such as postmarketOS.

Linux kernel fork: https://codeberg.org/ums9230-mainline/linux Sailfish OS port: https://forum.sailfishos.org/t/mainline-linux-kernel-for-the-jolla-c2/21382 postmarketOS port: https://wiki.postmarketos.org/wiki/Jolla_C2_(jolla-c2)