Autostart APP on console ttyO0

Hi at all,

I have a doubt about how can I start my app on console ttyO0, these are steps that I follow,

I have edited uEnv.txt
with this line

console=,115200n81 (without ttyO0)

I have try to autologin:

cp /lib/systemd/system/serial-getty@.service /etc/systemd/system/autologin@.service
rm /etc/systemd/system/
ln -s /etc/systemd/system/autologin@.service /etc/systemd/system/

Create the following script file in any location (/home/root/ in my case)
exec /bin/login -f root

Make it executable
chmod a+x

Edit /etc/systemd/system/autologin@.service and update the ExecStart command by adding the -n (Do not prompt the user for a login name) and -l (Invoke the specified login_program instead of /bin/login) options.

ExecStart=-/sbin/agetty -n -l /home/root/ -s %I 115200

My problem is I can read the output of my APP over console but I can`t write on ttyO0 (console).

Anybody can I help meā€¦thank you.