bruteuboot.py

import serial
import time
import string
failure = "Booting Linux on physical CPU" #this is the string we look for. If we find it we know we need to reset tthe device
ser = serial.Serial('/dev/tty.usbserial-A50285BI',baudrate=115200, bytesize=8, parity='N', stopbits=1, xonxoff=0, rtscts=0, timeout=0.1)
#dtr

def resetDevice(ser):
    ser.dtr = False
    time.sleep(1)
    ser.dtr = True

f = open('/Users/mwheeler/seriallog', 'w')

for key in string.printable:
    print "Testing with " + key
    data = ""
    loops = 0
    while (failure not in data):
        loops += 1
        ser.write(key)
        data = ser.readline()
        print(data)
        if loops > 100: #if it takes more than 100 loops before finding the failure then we might have a winner
            message = "Found possible escape - " + key + "\n"
            print message
            f.write(message)
            f.flush()
            break
    print "Key took - " + str(loops)
    resetDevice(ser)