On Sun, Aug 09, 2015 at 01:43:36AM -0400, Steve Litt wrote:
> On Sat, 8 Aug 2015 22:10:13 -0700
> Isaac Dunham <ibid.ag@???> wrote:
>
> > Try Alpine Linux (alpinelinux.org).
> > Install docs are here:
> > http://wiki.alpinelinux.org/wiki/Installation
>
> [snip]
>
> >
> > -init is Busybox init, with OpenRC on top.
>
> Fascinating! The Busybox PID1 with the OpenRC process adminstration is
> enough to make me install it. I'd love to learn Busybox init.

It's pretty much the same as sysvinit, with a few small differences:
-sysvinit inittab uses the format:
id:runlevel:action:process
Busybox init uses the format:
[tty]:[ignored]:action:process

So to start getty on tty1, use
tty1::respawn:/sbin/getty 38400 tty1

If there's no tty desired, remove the first field.

-Additionally, runlevels aren't supported by Busybox init.
OpenRC provides its own runlevels, with non-numeric names; these are no
longer built on sysvinit runlevels.

-(internal details) Busybox init doesn't use utmp for runlevels, nor does
it use /dev/initctl.
The only way of communicating with it is modifying inittab or signalling;
it knows at least these signals:
HUP    reload inittab
INT    ctrl-alt-del pressed
QUIT    reexec self
USR1    halt
USR2    poweroff
TERM    reboot

HTH,
Isaac Dunham