Hmm. This should not be complicated to achieve, but it's also very complex :)

You can simply do what Alexander suggested (init=/bin/bash), and you'll do fine.

The init process is what the kernel calls, and it kicks off all of your userland. Login terminal included. If your init just spawns that bash terminal, you're fine. But if that terminal crashes, or exits, init is supposed to clean up. If some of the processes you launch from terminal die, you need to clean up. If they die, then their children need a new parrent process, it'll be your init.

I highly recommend dedicating 10 minutes to read this, it's very friendly overview of what init does:

http://tilde.town/~elly/userland.txt

Then you'll get closer to understand what it entails to run your own init.

Hmm. This should not be complicated to achieve, but it's also very complex :)

You can simply do what Alexander suggested (init=/bin/bash), and you'll do fine.

The init process is what the kernel calls, and it kicks off all of your userland. Login terminal included. If your init just spawns that bash terminal, you're fine. But if that terminal crashes, or exits, init is supposed to clean up. If some of the processes you launch from terminal die, you need to clean up. If they die, then their children need a new parrent process, it'll be your init.

I highly recommend dedicating 10 minutes to read this, it's very friendly overview of what init does:

http://tilde.town/~elly/userland.txt

Then you'll get closer to understand what it entails to run your own init.

A relevant part of that link says:

There is only one thing we need to do: provide an initial binary to launch at any of these paths: /sbin/init, /etc/init, /bin/init, or /bin/sh. This process (init) is run as pid 1.

The init process needs to do two things:

• Never exit (if init exits, the kernel panics)

• Reap zombie processes

The rest of the text then implements a simple init.