Are there any plans - ongoing or not - to upgrade Halium-'s base to android 9? If not, what would have to be done to do so?
This has been asked/answered many times in different forms. Short answer is yes, we want to support newer devices that are android 8+ based. There is a project called hidl to help enable this. However, immediate priority is stabilizing the system and getting some things updated to latest versions, so it's easier to keep things stable going forward. Supporting new devices doesn't really help with that, and makes it more difficult, since there's more devices to test on, so it's a bit on the backlog at the moment.