EDIT 2013-11-24: As of kernel 3.12, the driver has been included in the staging area of the Linux kernel . Upgrading your kernel to get the included driver may be easier than compiling your own kernel module.
So I recently bought a TP-Link TL-WN725N wireless adapter to use together with my Raspberry Pi. The main reason to buy this particular model was that it should work out of the box together with the Linux kernel in Raspberry Pi.
It did not.
As it turns out, I have got the second version of the wireless dongle, which featured another chip – RTL8188EU. This chip does require another kernel module to be compiled and loaded into the kernel. Compiling kernel modules isn’t exactly my favourite way to spend my free time, so I looked desperately for some pre-compiled versions, but did not find any. Tough luck, eh?
Anyhow, here are the steps to produce a working kernel module for the dongle:
# pacman -S linux-headers-raspberrypi
$ git clone https://github.com/lwfinger/rtl8188eu
$ cd rtl8188eu $ vim Makefile
CONFIG_POWER_SAVING = yto
CONFIG_POWER_SAVING = n
$ CONFIG_RTL8188EU=m make -C /usr/src/linux-`uname -r` M=`pwd`
# install -p -m 644 8188eu.ko /lib/modules/`uname -r`/kernel/drivers/net/wireless/ # depmod -a # modprobe 8188eu