Confused pin configuration in PX4Flow Schematic

Dear all,
I saw in the PX4Flow schematic that pin 12 13 14 15 in GPIOE port are connected to 3.3V and GND respectively. Could you tell me what these pins are used for? Why should it be configured as such? I did not find any useful information in the FW. Thanks.

Could anyone give me some advises?

Hi this pins are not used. They are in low state and connect to GND, to prevent floating state of pin.

Thanks for the reply.
But, why these pins, the MCU has many other un-used pins, left alone, without connecting to GND or VCC.

good question, but you have to ask to someone who designed, maybe Lorenz Meier??

Thanks, I hope he could give me some answers. @LorenzMeier

Anyone could help me with it? I speculate if it is related with QGC recognition, because once connected, how does QGC know if it is a pixhawk, pixracer or px4flow.
Really appreciate if someone could give me some advises.