Hi
first of all this is not the right place to discuss.. it should be in "general discussions"
that said.. you can't compile on SME because there are no dev tools.. the best you can do is install a small centos 4.7 with dev tools and the same kernle as SME, compile your module and then copy it on SME..
BTW, SME does not support wifi, so, IMHO, you are wasting your time.. if you need something to create an acceso point/captive portale ecc you should take a look to another distro.
Ciao
Stefano