02-13-2016, 07:25 PM
Are you using the latest aarch64 rootfs? SysV init isn't supported out of the box in that -- systemd is the default init system. Also, ubuntu hasn't used /etc/inittab for quite a while. i enabled getty on ttyS0 with this script in /etc/init/ttyS0.conf:
start on runlevel [2345]
respawn
script
exec /sbin/getty -8 -a root 115200 ttyS0
end script
start on runlevel [2345]
respawn
script
exec /sbin/getty -8 -a root 115200 ttyS0
end script