I bought a Linksys AE1200 wifi dongle which has a Broadcom 43235 chipset, with the hope that it might just work on my RPi.
Well, of course it didn't but what surprised me was that it didn't work in Ubuntu 12.04 on my Dell E520 either.
This is surprising as I understand that the appropriate driver (brcmfmac) is available in kernel 3.2 and newer.
However, the above link provides a further link for some firmware which is necessary to get this Broadcom driver working.
I downloaded the latest snapshot and copied it as instructed.
However, the dongle remained invisible.
Nothing for it but to try out Ndiswrapper which should allow me to use the Windows XP driver in Linux.
This was easy to install as ndiswrapper-common, ndiswrapper-utils and ndiswrapper-dkms are all available in the Ubuntu repos.
I installed all three.
Then I downloaded the Linksys AE1200 driver for Windows XP from here, unzipped it and then used the following command to install the bcmwlhigh5.inf file to Ubuntu:
# ndiswrapper -i bcmwlhigh5.infNext, I ran
# ndiswrapper -mto enable the bcmw module to be loaded to boot.
Finally, I also need the ndiswrapper module to be loaded to boot.
For this I ran
# echo ndiswrapper >> /etc/modules
Next, just reboot and my dongle was recognized.
After adding the security key it's now available for use.
However, I still remain puzzled why the brcmfmac driver already available in the Ubuntu 12.04 kernel doesn't seem to work.
I emailed one of the developers to see what I'm missing.
Incidentally, I also asked him if an ARM version of the driver, suitable for a RPi, might be available soon.