isirc:
lvm instead symlinks (vgscan, ...) will be called with --sysinit.
flags:
NOSEC: default, on failure, isirc crashes and no shell will start.
but NOSEC will allow isirc to start a shell for debugging.
if you have a secure grub-config and nobody should be able to start
a root-shell, this will be default. else NOSEC is interesting for
debugging.
init: yes, init=/bin/sh will be possible. NOSEC is not needed.
isirdsh: start a shell before mounting. needs NOSEC.
ISIRDSH: start a shell after mounting and before switch root. needs NOSEC.
