How do I auto-login as root into the TTY upon boot?

source: http://linux.koolsolutions.com/2009/04/30/autologin-linux-console-mode.

I have gotten it to work, but it is slightly different on Ubuntu.

1. First install mingetty:

   sudo apt-get install mingetty
   

2. Edit /etc/init/tty1.conf:

   Change:

   exec /sbin/getty -8 38400 tty1
   

   To:

   exec /sbin/mingetty --autologin root --noclear tty1
   

3. Reboot and test.

This worked for me on Ubuntu 12.04, if this works for you and you need more tty's to autologin start changing tty2.conf - tty6.conf and you should be good to go.

In the modern world of systemd, here are the steps I took to get this working:

1. apt install mingetty

2. mkdir -p /etc/systemd/system/[email protected]

3. Now run the following script:

    cat > /etc/systemd/system/[email protected]/override.conf <<- "_EOF_"
    [Service]
    ExecStart=
    ExecStart=-/sbin/mingetty --autologin root --noclear tty1
    _EOF_
   

4. systemctl enable [email protected]

The above seems to be the cleanest option for systems that use Systemd that I could find. As an added bonus, if something breaks in the future, you can just run something like the following from a recovery live ISO (after mounting the root partition of course), to restore default behavior:

rm /mnt/root/etc/systemd/system/[email protected]/override.conf