BeagleBone UARTs

[fvcuts]

Hi, I would use UARTs on BeagleBone. When I send data to /dev/ttyO1 (or 2... and so on) device I cannot see any movement on board pins. Googling I see that I have to change pin mode to access UART. I should use /sys/kernel/debug/omap_mux.
But here is the problem, that dir is void. No file inside. What do I miss?

Thank You

[fvcuts]

Solved!
mount -t debugfs debugfs /sys/kernel/debug

[fvcuts]

Ok, next problem.. Ok for tx and rx muxing pins, but I cannot see RTS works properly.
It seems a diffuse problem (google says...). Do anyone use correctly RTS on port 1 or 2?

Thank You