[$] Bringing the Android kernel back to the mainline

Android devices are based on the Linux kernel but, since the beginning,
those devices have not run mainline kernels. The amount of out-of-tree
code shipped on those devices has been seen as a problem for
most of this time, and significant resources have been dedicated to reducing it.
At the 2018 Linux Plumbers
Conference, Sandeep Patil talked about this problem and what is being
done to address it. The dream of running mainline kernels on Android
devices has not yet been achieved, but it may be closer than many people think.