allows us to change the uart(4) driver to not hardcode specific line
settings for the serial console.
A terminal type of 3wire makes sure the console still works when no DCD
signal is present, which preserves behviour. When it is known that the
terminal server (or DCE in general) provides DCD, a terminal type/class
of std can be used. This has the effect of being logged out when one
disconnects from the console -- improving security overall.
Likewise, when uart(4) does not fixate the baudrate, one can change
the terminal type/class to set a specific baudrate. An operator can use
this to change the console speed mid-flight, without needing a reboot.
Of course it helps in this respect if and when the firmware can be
configured from the OS.
The above mentioned capabilities depend on uart(4) being changed, which
is to happen next.
bc0770d707