How do you redirect user to login prompt at the beginning?

[LinArcX]

Hi. I really like this project. It's very awesome.

I'm building my own distro using linux+busybox. but I stuck at one thing:

I still couldn't understand at the beginning of the boot, how you redirect users to login entry.

I saw your video and you did it well. Also, I read the source code, but couldn't find exactly at which point you're doing this.