I'm not sure what happens with onboard in GDM. As far as I know gnome-shell will have a built-in on-screen keyboard and thus onboard might be replaced in GDM too. Jeremy could probably tell you more about this.
If you still want to try, playing with or creating /usr/share/gdm/autostart/LoginWindow/onboard.desktop may be the way to go.
Lightdm has an option to start onboard now, only the actual typing isn't working yet. There is a fix on it's way apparently with unity-greeter-0.0.9. It's not in the repos yet though. https://bugs.launchpad.net/unity-greeter/+bug/851565
I'm not sure what happens with onboard in GDM. As far as I know gnome-shell will have a built-in on-screen keyboard and thus onboard might be replaced in GDM too. Jeremy could probably tell you more about this. gdm/autostart/ LoginWindow/ onboard. desktop may be the way to go.
If you still want to try, playing with or creating /usr/share/
Lightdm has an option to start onboard now, only the actual typing isn't working yet. There is a fix on it's way apparently with unity-greeter- 0.0.9. It's not in the repos yet though. /bugs.launchpad .net/unity- greeter/ +bug/851565
https:/