Liberate the serial port

[freebsd at casidy.com]

Hi,


I have a Raspberry Pi2 and I am struggling at using the serial port 
uart0 for my own purpose.

I have install 11.0-RELEASE-p1 a few months ago and now I have attached 
a device that send characters on the Raspberry uart0 and I try to read 
them by a

setting the tty

stty -f /dev/ttyu0 1200 sane evenp parenb cs7 -crtscts


trying to read

cat /dev/ttyu0

or cat < /dev/ttyu0


But my understanding is that the kernel at some point grabbed uart0 to 
provide a serial console.


I tried to change /etc/ttys

ttyu0   "/usr/libexec/getty 3wire.115200"       vt100   off secure

but no avail, I have nothing while trying to cat /dev/ttyu0.


I tried with Raspbian, and after disabling the use of the uart as a 
console on boot, I have been able to get my characters... so the 
hardware works fine.


How can I use my serial port for another purpose than a serial console?

What am I missing?


Thanks in advance,

Philippe