LG G4 internals: My messy jots

Introduction These are my really messy jots as I tried out things with my LG G4 H815 phone (Android 5.1, kernel 3.10.49, software version V10e-ISR-COM from Aug 17, 2015, not locked to any specific network). I usually try to get the post tidy so it becomes some kind of how-to post, but this time I [...]