init: illegal runlevel (null)

[Tom H]

>  here is a description of what I'm trying to do.
>
> I created a small rootfs with buildroot and I gPXE booted it. Once that is
> running I do
>
> mount -t tmpfs -o size=4G mount -t tmpfs -o size=4G none /tmp
>
> (I have a system with 8GB of RAM)
>
> and then i copy with scp a new rootfs (rootfs.img whose size is around
> 2.5GB) under /tmp
>
> At this point, this I run this simple script
>
> #!/bin/bash
> cd /tmp
> mkdir newrootfs
> mount rootfs.img newrootfs
> cd newrootfs
> mkdir oldrootfs
> pivot_root . oldrootfs
> exec chroot . sh -c 'exec /sbin/init' <dev/console >dev/console 2>&1
>
> I can see the new root is rootfs, but still there is something not working.
> When I run the script I get the message
>
> init: illegal runlevel (null)
>
> Any idea of what can be wrong?

The script calling "exec chroot . sh -c 'exec /sbin/init'..." has to
have pid 1 otherwise init will expect a run level.