uart supports read and write operations for the PL011 UART device
featured on the board on GPIOs 14 and 15 (pins 8 and 10).
Baud and other settings can be set by using the termios, note that
most of the fields are not implemented, only the ones related to input stream
settings.
The default baud for the device is set to be 115200.
watchdog represents the hardware watchdog included with the board.
Writing to it will reset it, ioctl operations may be used for
timeout configuration and starting/stopping it.