- the factory flash tool needs the device to be plugged in _after_ it scans or starts - the scatter file it uses is basically just a list of mappings between filenames and partitions: or at least, it performs uploads if I treat it that way - using that approach I flashed the twrp but the phone does not boot when this is flashed. it could be because it's still locked. - the flashing baud rate is 921600 . this may be used to engage the ttyACM serial device the phone briefly exposes before boot. 1328 - I put the system images on a new partition but windows isn't recognising it. I ended up rebooting since kvm didnt seem to be working. noting the size of this partition would let me reformat it under windows. - in the twrp instructions it says "fastboot flashing unlock" , sounds important