[yocto] Runtime update of yocto-images

[Marc Ferland]

Julian Scheel <julian at jusst.de> writes:

> Hi,
>
> I wonder how everyone deals with runtime updates of yocto based
> systems? Are you using the package management for this? Actually I'd
> prefer a one-file update, which would replace the whole rootfs. I
> think having a squashfs image containing the rootfs and place it on
> some ext-partition would be nice. One would just need an initramfs,
> that could mount the squashfs file as root.
>
> Is anyone following an approach like this?

This is the approach that I've taken. Works fairly well.

You will need to:
- Create your own init script (look in:
meta/recipes-core/initrdscripts/files as a starting point)
- Patch your kernel with AUFS/unionfs/overlayfs if you want something
that is not 100% volatile.
- Create an "install/update" script that actually takes care of updating
your squashfs rootfs from the initramfs.

Marc