#!/bin/bash

SERIAL_PORT="/dev/ttyGS0"
stty -F "$SERIAL_PORT" raw

while true
do
    if read -r line < "$SERIAL_PORT"
    then
        # wait for done message
        if [ "$line" = "DONE" ]
        then
            echo "" > /sys/kernel/config/usb_gadget/g1/UDC
            exit
        fi
    fi
    sleep 0.5
done