On Mon, 3 Jan 2022 18:45:28 +0100 (CET)
karl@??? wrote:

> I have used busybox init for a while. It differs from sysvinit
> by not having runlevels, except perhaps on and off.
>
> Busybox repo is at: git://busybox.net/busybox.git
> Website at: https://busybox.net/
> Comment re. systemd: https://busybox.net/kill_it_with_fire.txt
>
> Example inittab at:
> https://git.busybox.net/busybox/tree/examples/inittab
> excerpt:
>

> # Note: BusyBox init works just fine without an inittab. If no inittab is
> # found, it has the following default behavior:
> #       ::sysinit:/etc/init.d/rcS
> #       ::askfirst:/bin/sh
> #       ::ctrlaltdel:/sbin/reboot
> #       ::shutdown:/sbin/swapoff -a
> #       ::shutdown:/bin/umount -a -r
> #       ::restart:/sbin/init
> #       tty2::askfirst:/bin/sh
> #       tty3::askfirst:/bin/sh
> #       tty4::askfirst:/bin/sh

>
> The sysinit thing is a how you start the system, it's just
> one script /etc/init.d/rcS (or where you prefer to place it).
>
> One could possible (not tested) mimic sysvinit bootup by having
> for i in /etc/rc2.d/S*; do $i start; done
> in the rcS file or if you prefer you can have your own handwritten
> and tuned script there.
>
> Would there be any interests having a busybox_init package which
> I could possible maintain (with a little help) ?
>
> Regards,
> /Karl Hammar
>

Hi,
just to add my 2 cents.

I would build a static compiled busybox binary with:

init
a shell
reboot, shutdown
swapon/swapoff
mount, umount
(start-stop-daemon)
(getty, login)

able to fully bring up a system.
We could call it systemB like the other one but _B_etter.
Then we implant it as blob into the kernel image
so that we get rid also of initrds creating a
PAC man like GNU/Linux/systemB/Frankenstein monster
that eats all little sysDs.

Ciao,
Tito