If you want to auto login and startx without a display manager in Debian use the one of the following method

Method 1

First you need to edit the /etc/inittab file

#nano /etc/inittab

look for the following line

1:2345:respawn:/sbin/getty 38400 tty1

and commentout

#1:2345:respawn:/sbin/getty 38400 tty1

add the following line

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

Save and exit the file

Now you need to edit .bash_profile and at the bottom add the following command and save

startx

Method 2

First install rungetty using the following command

#apt-get install rungetty

you need to edit the /etc/inittab file

#nano /etc/inittab

look for the following line

comment out

#1:2345:respawn:/sbin/getty 38400 tty1

and add

1:2345:respawn:/sbin/rungetty tty1 -- autologin YOUR_USER_NAME

edit .bash_profile and at the bottom add

if [ -z "$DISPLAY" ] && [ $(tty) = /dev/tty1 ]; then

while true

do

startx --

sleep 10

done

fi