J2 has a 3.3V serial lines (TX, RX, GNC and Vcc) and 6 unknown pines. I've tried to load a linux kernel through the serial port with no luck. There is a person, blogic, who alledgely has been able to boot linux in this board, but there is no instructions nor manual.
Also, I've read that the WIFI calibration data is stored somewhere in the flash memory and that booting linux can erase and overwrite that data leaving the atheros chip useless.