To make RealTek 8180 wireless cards work in Linux you need the open source drivers from rtl8180-sa2400. Actually this driver supports more realtek cards not just 8180, you can get the list of supported devices from their homepage.
The only problem with those drivers is that they are a bit outdated. They were initially build sometime in 2005 at a time when the kernel version was 2.6.12 . Since then there were patches released to make those drivers work with newer kernels and the latest patch I found was for kernel 2.6.22.You can download the patch from sourceforge . I downloaded that and it just complied and installed without problems.
I loaded the following kernel modules in the exact order :
At this point I got the card working but there was no security. I knew this card supports WEP encryption and I was trying to set up a link between the card and a linksys WRT54G router that can also do WEP. When I tried to set a key (WEP ) I the card told me setting a key was not supported by hardware and I got the following error in dmesg: rtl_ieee80211_crypt_wep: could not allocate crypto API arc4
This was very weird because I knew I already loaded the arc4 crypto module . Then why doesn't it work?
After digging a bit in the code I realize that the ecb module is also needed for kernel versions higher then 2.6.15.
After I loaded the ecb module I was able to set a key with iwconfig and the link was up.
To summarize...
in order get this driver working you have to compile your kernel with the following options:
-> Networking
-> Networking support (NET [=y])
-> Wireless
-> Improved Wireless API
for the wireless tools ( iwconfig ) to work
Device Drivers
-> Wireless LAN
I'm not sure if this one is really needed cause the rtl8180 drivers user their own 802.11 stack but it doesn't hurt to enable it as a module, and if you have other wireless devices or you want to ue your card as a host ap you may need tis anyway.
From the Cryptographic API make sure you select ARC4 and ECB
After you compile the kernel you need to load the modules like this:
bring up the interface :
and set the ESSID and key with iwconfig in order to connect it with the Access point
If everything went well you should see something like: wlan0 802.11b linked when typing iwconfig
Next i will try to configure this card to be used as a Host AP.
Did any of you try that ? feel free to share your experiences in the comments.
Update:
There is a new project that forked the rtl8180 driver and ported it to the new 802.11 stack in 2.6.23 kernel. This new project was already included in 2.6.23 but at the moment only support for rtl8185 is available. The project is rtl-wifi and you might want to watch their page for when they add support for 8180