Both 'utmp' and 'root' groups are mentioned in tmpfiles.d/systemd.conf
and as such should be included.
It's probably better to have something equiv to inst_rule_group_owner()
for udev rules which parses out users and groups and adds them to the
passwd/group db respectively.
Could also rely on sysusers but as the initramfs is static in this
sense, it's more efficient to pre-define the users IMO.
grep '^systemd-journal:' /etc/group >> "$initdir/etc/group"
grep '^wheel:' /etc/group >> "$initdir/etc/group"
grep '^adm:' /etc/group >> "$initdir/etc/group"
+ grep '^utmp:' /etc/group >> "$initdir/etc/group"
+ grep '^root:' /etc/group >> "$initdir/etc/group"
ln_r $systemdutildir/systemd "/init"
ln_r $systemdutildir/systemd "/sbin/init"