www.naumann.cc

As descibed here we have to install the kernel headers first:

sudo apt-get install build-essential linux-headers-$(uname -r) subversion

Now we can add the madwifi drivers for the wlan chipset:

cd /usr/local/src
svn checkout http://madwifi-project.org/svn/madwifi/trunk madwifi
cd madwifi
make
sudo make install
sudo modprobe ath_pci

You can find some additional Information of putting madwifi into a kernel at this page. (German)

We have to do some additional configuration first we have to add the module to /etc/modules:

echo "ath_pci" >> /etc/modules

I added some scripts following the howto.