Sony is adding new phones to the Open Devices program. This means more Xperia models will soon run Android Pie. We know the Android 9 Pie update will be coming to some of the latest Sony Xperia phones. While waiting, Xperia users can try to develop their own and flash Android 9. In case you’ve been living under a rock, Sony’s Open Devices program offers access and delivers tools to developers and Xperia phone owners. This allows devs to test custom software that could run on other Sony phones, even the older models.
Once you’re part of the Open Devices program, you are free to access the tools you may need to start building any custom software. You can see on the Developer World’s Open Devices page all the resources available.
Note the build may be unstable for now. Feel free to share feedback and report any problem you may encounter as you begin building AOSP for your device.
SOURCE: Sony Mobile