Serial ports permissions in android


Im making app in unity for android, which will be reading from serial com port… At this time i cant
try it on prototype so im preparing. So i made simple script which will start and list all available.

 void Start()
        string[] s = SerialPort.GetPortNames();

        for (int i = 0; i < s.Length; i++)
            portList.text += s *+ "


But i when i run script on my test tablet nothing happens. After looking at logs through Android Monitor from android SDK, i can see unity throwing UnauthorizedAccessException: Access to the path “/dev” denied. I looked it up and there is nothing about this at all. So Im guessing that either im doing something wrong or i need rooted tablet…
So i know how to work with com ports… i just need access to them on android.
Can you please help me ?

Did you find a solution to this?