BeagleBoneBlue configuration is going forward.
Few problems with rc.local, solution with systemd and creation of a service.
Initial problem (rc.local not working) may be due to syntax error in the wiki rc.local example:
/bin/echo uart > /sys/devices/platform/ocp/ocp\:P9_21_pinmux/state
/bin/echo uart > /sys/devices/platform/ocp/ocp\:P9_22_pinmux/state
/bin/echo pruecapin_pu > /sys/devices/platform/ocp/ocp:P8_15_pinmux/state
/home/debian/arducopter -B /dev/ttyO2 -C /dev/ttyUSB0 > /home/debian/arducopter.log &
When running it, I have an error with :P8_15_pinmux/state:
Sep 12 13:45:21 beaglebone rc.local 17: /etc/rc.local: cannot create /sys/devices/platform/ocp/ocp:P8_15_pinmux/state: Directory nonexistent
May be it is due to \ missing before :P8 (could be ocp/ocp\:P8_15_pinmux/state)
(I removed the line from rc.local).