Tools: uploader: open serial port in exclusive mode

[Williangalvani]

This helps preventing other software from attempting to use the serial ports while flashing a new firmware

[peterbarker]

This helps preventing other software from attempting to use the serial ports while flashing a new firmware

Does this break if MAVProxy currently has that port open?

[Williangalvani]

This helps preventing other software from attempting to use the serial ports while flashing a new firmware

Does this break if MAVProxy currently has that port open?

No, this will only fail if both pyserial instances try to open the port using exclusive=True, which mavproxy doesn't

[Williangalvani]

It only prevents another instance of pyserial from opening a new "exclusive=True" instance on the same port: (The top panel opened the port before the second panel, and kept it open)