#!/usr/bin/env python3
import serial
import struct
import time
import binascii

SERIAL_PORT = '/dev/ttyUSB1'
BAUD_RATE = 9600

def calculate_checksum(data):
    """Calculate XOR checksum for AMT protocol"""
    checksum = 0
    for byte in data:
        checksum ^= byte
    return checksum

def create_amt_packet(msg_id, payload=b""):
    """Create properly formatted AMT packet"""
    # Message structure: [0x02][msg_id][payload][checksum][0x02]
    msg = struct.pack('>H', msg_id) + payload  # Big-endian message ID
    checksum = calculate_checksum(msg)
    packet = b'\x02' + msg + bytes([checksum]) + b'\x02'

    # Add 4-byte length header (little-endian)
    length = len(packet)
    return struct.pack('<I', length) + packet

def send_serial_command(ser, msg_id, payload=b""):
    """Send command via serial and read response"""
    packet = create_amt_packet(msg_id, payload)
    print(f"[*] Sending: {binascii.hexlify(packet)}")

    ser.write(packet)
    time.sleep(1)  # Wait for response

    # Read available data
    response = ser.read_all()
    if response:
        print(f"[+] Response: {binascii.hexlify(response)}")
    else:
        print("[!] No response received")

# Key message IDs from analysis
MSG_SET_BOOT_MODE = 0x1000
MSG_NVRAM_COMMAND = 0x1FFF
MSG_GET_VERSION = 0xD1
MSG_GPS = 0x100D

def gps_poweron(ser):
    """Attempt to turn on GPS"""
    send_serial_command(ser, MSG_GPS, b'\x01')

def gps_poweroff(ser):
    """Attempt to turn off GPS"""
    send_serial_command(ser, MSG_GPS, b'\x00')

def change_boot_mode(ser):
    """Attempt to change boot mode"""
    # Try setting boot mode to debug (may enable more features)
    send_serial_command(ser, MSG_SET_BOOT_MODE, b'\x01')  # 1=debug mode

def main():
    try:
        with serial.Serial(SERIAL_PORT, BAUD_RATE, timeout=1, rtscts=True, dsrdtr=True) as ser:
            print(f"[*] Connected to {SERIAL_PORT}")

            # First verify communication
            send_serial_command(ser, MSG_GET_VERSION)

            change_boot_mode(ser)

    except Exception as e:
        print(f"[!] Error: {str(e)}")

if __name__ == "__main__":
    main()