If you're using a persistent overlay, you might want to reset it
at boot time if it has become corrupted somehow. Support using
reset_overlay as a command line optino to do so
The persistent overlay can be specified with an overlay= argument
on the command line. We'll probably try to move this into the
root= syntax soon, but this is the old way that works
Fedora/Red Hat live images are implemented as an ext3fs inside of
a squashfs. Writability is achieved with a device-mapper snapshot
on top of that.
This gives the basic support without a lot of things like persistent
overlays, iso md5sum checking, etc and also with a new basic syntax
that has to be specified as root=live:LABEL=...
Harald Hoyer