init-live.sh: distinguish between a read-only image and a read-write image
The iso and hddimg share a common concept of 'live image', and they
use the same initramfs and thus the same init. However, that init
script in initramfs made a wrong assumption that the rootfs image
was read-only by itself. This is apparently not true for hddimg.
To make things work as expected, this init script should at least
distinguish between a read-only rootfs image and a read-write one.
This patch adds this ability to the init script. After this change,
the init script would be able to check whether the rootfs image is
read-only or not. If the rootfs image is read-write, the image will
be mounted and then booted directly. No union mounts will be attempted
in this case.
[YOCTO #5164]
Signed-off-by: Chen Qi <Qi.Chen@windriver.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
