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

Question

I am working on creating a real time kernel with RT-PREEMPT patch. I have created this kernel without graphic desktop. It comes up in the terminal mode with login prompt. The requirement is, it should boot and directly go to the shell prompt with root permission, without asking for login. How can this be done? Can you help me?

Answer 1

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.

Answer 2

You can do this without any additional software

sudo vim /etc/inittab

comment out

1:2345:respawn:/sbin/getty 115200 tty1

and replace it with

1:2345:respawn:/bin/login -f pi tty1 </dev/tty1 >/dev/tty1 2>&1

so you are left with this

#1:2345:respawn:/sbin/getty 115200 tty1
1:2345:respawn:/bin/login -f pi tty1 </dev/tty1 >/dev/tty1 2>&1