[systemd-devel] systemd initrd

[Michael Di Domenico]

can anyone point me towards some howto's or documentation that shows
how one might replace an existing busybox based initrd with a systemd
one?

obviously this is a bit of a loaded question as you have no idea what
i'm doing in the initrd, but i'm not sure where to get started.  to
break it down simply;

with busybox, i can compile a kernel, compile busybox, add my junk to
the init script and then make an initrd image that the kernel loads.
at the end of the initrd if all "my junk" worked, I then switchroot to
boot up a linux o/s

i want to basically do the same thing with systemd, take a kernel,
hand off to an initrd where systemd would start a shell if needed
(like busybox does) or switchroot to boot up the o/s

i know systemd doesn't provide all the little utils that busybox does,
but that's okay, i can just pull them into the initrd

i've spun myself in google circles at this point and need some
straightening out and the system switch-root/initrd pages are a little
to terse