Re: [RAUC] Is it possible to change the [system]compatible= string after it has already been set/flashed?

[Brian Hutchinson via RAUC <rauc@pengutronix.de>]

On Mon, Dec 9, 2024 at 3:43 AM Jan Lübbe <jlu@pengutronix.de> wrote:
>
> Hi again,
>
> On Thu, 2024-12-05 at 22:38 -0500, Brian Hutchinson via RAUC wrote:
> > This almost feels like the intermediate update that's necessary with
> > changing rauc versions ...
>
> Enrico pointed me to this part.
>
> Updating RAUC versions normally does *not* require an intermediate
> update. An intermediate update is only needed if you explicitly create
> bundles which use new features:
> https://rauc.readthedocs.io/en/latest/basic.html#forward-and-backward-compatibility

Thanks!

I should probably start another thread, but now I'm running into a
chicken & egg problem.

I need to add downgrade protection due to newer hardware and I
discovered pre-install handler doesn't have access to bundle version
(RAUC_MF_VERSION), only a hook has that environment variable.  Well,
if I create a hook that can compare bundle version to current version
to do some hardware checks ... that hook won't be in older bundles, so
wondering how pre-install handler (which lives in the current version
file system) can figure out the bundle version attempting to be
installed if it can't see RAUC_MF_VERSION to implement downgrade
protection if that makes any sense.

Regards,

Brian