About drivers and how create one

Wed Sep 16 14:38:46 UTC 2015

   Hi all,

      I bought a wireless mini usbcard, to test in
FreeBSD, but it not reconized.  In CD have a Linux
source driver.
      My Question is :  How hard is to convert a source
code Linux to FreeBSD and where I can found information
about it?

     The CHIP under device is Ralink rt28XX.

     I'm using a FreeBSD -current

uname -a
FreeBSD leblon 11.0-CURRENT FreeBSD 11.0-CURRENT #10 r285290: Wed Jul  8
21:50:30 BRT 2015     rizzo at leblon:/usr/obj/usr/src/sys/LEBLON  amd64

     P.S. I Have a good knowledgement in C/C++ and assembler, but I never
wrote a kernel module.

  TIA

---
/*************************************************
**Nilton José Rizzo            UFRRJ
**http://www.rizzo.eng.br      http://www.ufrrj.br
**http://lattes.cnpq.br/0079460703536198
**************************************************/