[systemd-devel] Context for "exitrd"

[Albert Brox]

Hi all,

I'm interested in working on this item from the TODO file:

* add concept for "exitrd" as inverse of "initrd", that we can 
transition to at
   shutdown, and has similar security semantics. This should then take 
the place
   of dracut's shutdown logic. Should probably support sysexts too. Care 
needs
   to be taken that the resulting logic ends up in RAM, i.e. is copied 
out of
   on-disk storage.

I'm wondering if anyone can elaborate/give context for this. 
Specifically, what is the motivation for replacing the dracut shutdown 
logic with exitrd? It seems like dracut already handles shutdown 
processes within a ramdisk/fs. And as I understand, initrd is not part 
of systemd (merely interfaced with), so why are we bringing this 
"exitrd" under the umbrella of systemd?

Additionally, is there any source code I can reference for an idea of 
how to implement this?

Regards,
Albert