Quick copy and paste from that forum here, for keeping it simple. All credits to the author. Besides, that link changed once and I could not find it when I needed it for a second time...
Re: Atheros Communications Inc. AR242x 802.11abg Wireless PCI Express Adapter (rev 01
Thanks so much to those above for figuring this out for me. Let me spell out the installation in a little more detail to save those after me some time.
I did this on a fresh Ubuntu 8.04 install on a Compaq Presario C770US Laptop with an ethernet cable plugged into my router.
The device string displayed by lspci -v was as follows:
01:00.0 Ethernet controller: Atheros Communications Inc. AR242x 802.11abg Wireless PCI Express Adapter (rev 01)
Subsystem: Hewlett-Packard Company Unknown device 137a
Flags: bus master, fast devsel, latency 0, IRQ 16
Memory at 91300000 (64-bit, non-prefetchable) [size=64K]
Capabilities: <access denied>
First under System/Administration/HarwareDrivers disable both the Atheros HAL and the Atheros wireless thing and then reboot.
The kernel headers and the compiler are needed to build this driver so I started by installing build-essential. In a terminal window (Applications/Accessories/Terminal) enter:
sudo apt-get install build-essential
The driver code will be downloaded with the subversion source code manager so I installed subversion:
sudo apt-get install subversion
I needed a place to put the driver source without mixing it up with other stuff so I changed directory to my home directory:
Created a directory:
And changed to the new dirctory:
Use subversion to download (checkout) a copy of the code:
svn co https://svn.madwifi.org/madwifi/branches/madwifi-hal-0.10.5.6
The above command failed for me at first because subversion couldn't find svn.madwifi.org
Madwifi will probably have their DNS problems worked out by the time you read this. But if not then see the section at the bottom of this post titled "Cant find svn.madwifi.org" for a solution before continuing.
After the driver code is downloaded by subversion, change to the directory, which should be madwifi-hal-0.10.5.6
Run the make script to have the compiler build the driver:
Install the driver
Add the Atheros kernel module to the list of modules to be automatically loaded at boot by adding "ath_pci" (without the quotes) to the end of the /etc/modules file. I used the vi editor which I won't describe here. Gedit is probably easy to use so try:
sudo gedit /etc/modules
Now you can reboot and it should work. To get it working without a reboot you need to load the module manually:
sudo modprobe ath_pci
That should do it. The little wireless button seems to always stay lit orange. When I press it it seems to disable the wireless but it still stays lit orange. WPA works for me. I assume WEP will also. I haven't tried WPA2
CANT FIND svn.madwifi.org
If subversion has a hard time finding svn.madwifi.org then add it's IP address to your hosts file. I found this page http://madwifi.org/ticket/1982
at madwifi.org that gives the IP address 220.127.116.11 of svn.madwifi.org in one of the last messages. I tried just giving subversion the command to connect to the IP address instead of the domain name, but it failed before finishing the checkout. Edit the file /etc/hosts and add "18.104.22.168 svn.madwifi.org" (without the quotes). I added it just after the 127.0.1.1 line
sudo gedit /etc/hosts
Now you can continue with the subversion checkout. You should probably remove this line from your hosts file when you're done with this so that if you want to go back there some day and they've moved it then DNS will give the most recent IP address.