gpsd is a service daemon that monitors one or more GPSes attached to
a host computer through serial or USB ports, making all data on the
location, course, and velocity available to be queried on TCP port
2947 of the host computer.  With gpsd, multiple GPS client applications
(such as navigational and wardriving software) can share access to GPSes
without contention or loss of data.  Applications that presently use
gpsd include Viking and Kismet.

See README.build for some additional build options that might be useful.

To enable automatic startup of gpsd at boot time, or when a GPS device is
connected via USB, you need to do the following three steps:

1. Edit the file /lib/udev/rules.d/97-gpsd.rules and uncomment the line
(or lines) beginning '#ATTRS' that corresponds to your GPS hardware and
save it in /etc/udev/rules.d/. To avoid confusion with other USB serial
devices that you might have, do not uncomment lines that do not
correspond to your GPS hardware.

2. Make the file /etc/rc.d/rc.gpsd executable.
   chmod +x /etc/rc.d/rc.gpsd

3. Add the following lines to /etc/rc.d/rc.local
  if [ -x /etc/rc.d/rc.gpsd ]; then
    /etc/rc.d/rc.gpsd start
  fi

Configuration options may be set in the file /etc/rc.d/rc.gpsd.conf.  The
defaults will usually be adequate.  However, if your GPS is on a real (non-USB)
serial port -- for example, /dev/ttyS0 -- you should add /dev/ttyS0 to
GPS_DEVICES in /etc/rc.d/rc.gpsd.conf.