It's often desired in Embedded System design to have a read-only rootfs.
But a lot of different applications might want to have a read-write access
to some parts of a filesystem. It can be especially useful when your update
mechanism overwrites the whole rootfs, but you want your application data
to be preserved between updates. This class provides a way to achieve that
by means of overlayfs and at the same time keeping the base rootfs read-only.
Signed-off-by: Vyacheslav Yurkov <uvv.mail@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>