I was curious about this and have also been dealing with serial port stuff all day today - so here is what I find.
You can setup 'special-login' and supposedly upon login you will be auto connected to the serial port, but this does not work for some reason. When entering the following you can get connected and then grab the GPS if thats what you want.
[gps@mikroHome] > /sys serial-terminal serial1
[Ctrl-X is the prefix key]
1,06,2.3,189.8,M,-34.9,M,0.0,0000*43
$GPGSA,A,3,03,19,22,21,18,15,,,,,,,3.2,2.3,2.3*36
$GPRMC,072xx3.409,A,3xx9.8098,N,11xx0.8539,W,0.12,189.78,071105,,*10
$GPGGA,072054.409,3xx9.8098,N,11xx0.8539,W,1,06,2.3,189.9,M,-34.9,M,0.0,0000*45
$GPGSA,A,3,03,19,22,21,18,15,,,,,,,3.2,2.3,2.3*36
$GPGSV,3,1,09,15,68,055,46,22,64,313,49,18,52,033,48,21,44,100,47*77
$GPGSV,3,2,09,14,40,197,00,03,39,290,43,19,15,318,37,01,06,207,00*7A
$GPGSV,3,3,09,06,05,162,00*46
$GPRMC,072054.409,A,3xx9.8098,N,11xx0.8539,W,0.08,181.02,071105,,*19
$GPGGA,072055.409,3xx9.8098,N,11xx0.8539,W,1,06,2.3,189.9,M,-34.9,M,0.0,0000*44
$GPGSA,A,3,03,19,22,21,18,15,,,,,,,3.2,2.3,2.3*36
$GPRMC,072055.409,A,3xx9.8098,N,1xxx0.8539,W,0.08,183.03,071105,,*1B
$GPGGA,072056.409,3xx9.8098,N,11xx0.8538,W,1,06,2.3,189.9,M,-34.9,M,0.0,0000*46