[PATCH 0/6] Add support for fwumdata

[Kory Maincent]

On Wed, 3 Dec 2025 11:26:59 -0600
Tom Rini <trini at konsulko.com> wrote:

> On Wed, Dec 03, 2025 at 06:13:29PM +0100, Kory Maincent wrote:
> > On Wed, 3 Dec 2025 09:10:48 -0600
> > Tom Rini <trini at konsulko.com> wrote:
> >   
> > > On Wed, Dec 03, 2025 at 03:59:24PM +0100, Kory Maincent wrote:  
> > > > On Wed, 3 Dec 2025 15:04:10 +0100
> > > > Patryk <pbiel7 at gmail.com> wrote:
> > > >     
> > > > > Hi Ilias,
> > > > >     
> > > > > > > > Add a new fwumdata tool to allows users to read, display, and
> > > > > > > > modify FWU (Firmware Update) metadata from Linux userspace. It
> > > > > > > > provides functionality similar to fw_printenv/fw_setenv but for
> > > > > > > > FWU metadata. Users can view metadata, change active/previous
> > > > > > > > bank indices, modify bank states, and set image acceptance
> > > > > > > > flags. Configuration is done via fwumdata.config file.
> > > > > > > >
> > > > > > > > Made a few change to mkfwumdata tool along the way.      
> > > > > > >
> > > > > > > Still wondering about the choice of putting this fwumdata tool in
> > > > > > > U-Boot instead of TF-A. TF-A is the boot part that manages the
> > > > > > > update process and rollback through the FWU metadata,
> > > > > > > therefore, this is where it should belong.
> > > > > > > Why, in the first place, mkfwumdata was accepted into U-boot
> > > > > > > instead of TF-A?      
> > > > > >
> > > > > > The actual update happens via capsule updates only, which runs in
> > > > > > BL33. TF-A needs to be aware in case it's involved in the boot
> > > > > > process and fails to boot. In that case BL2 is responsible for
> > > > > > booting via the other bank.
> > > > > > But generally speaking it's U-Boot that processes and usually
> > > > > > updates that file      
> > > > > 
> > > > > If I may add something - actually for me this is not that obvious,
> > > > > e.g. on our platform we update the metadata directly from Linux, not
> > > > > from the u-boot capsule. As far as I'm aware, the ST, in their
> > > > > OpenstLinux does the same. I'm also not sure why it would be the bad
> > > > > idea to do this from Linux. Ofc the BL2 handles bank selection as well
> > > > > as rollback in case of boot failure on a newly selected bank.    
> > > > 
> > > > I agreed with Patryk. U-boot is only an update agent (as explained by
> > > > the standard) of FWU metadata as Barebox or Linux could be. FWU
> > > > metadata is an ARM standard which is related to the update of the
> > > > images that boot after the ARM firmware. It is not related to any
> > > > project. As TF-A is the mainstream project for ARM firmware having
> > > > mkfwumdata and fwumdata in it seems more suitable. I am not familiar
> > > > with these EFI capsule update, does it not rely on TF-A to select the
> > > > boot image according to the FWU metadata state?
> > > > 
> > > > Anyway, now it is too late and mkfwumdata has already landed in U-boot
> > > > for 2 years. Not sure what we should do here. Put all in U-boot and let
> > > > the other projects (barebox) copy the code if they need it? Or move all
> > > > to TF-A while keeping a deprecated copy of mkfwumdata in U-boot to not
> > > > break things?    
> > > 
> > > Perhaps in the medium term we can split that tooling out from the main
> > > project source tree itself, to make it easier for OSes to use this tool
> > > (and other tools we have). There's nothing U-Boot specific about this,
> > > if I'm following the thread right.  
> > 
> > This isn't clear to me.
> > Are you saying that we should plan in removing mkfwumdata in the medium
> > term? And in the short time, sending the two tools to TF-A to get them
> > accepted.  
> 
> I mean in general, there are a lot of things in the u-boot source tree
> that may or may not really make sense to have, in tree. We also can't,
> right now, easily support or handle having multiple distinct projects
> under the u-boot umbrella. I'm wondering if we should figure out how
> to support a few source repositories under our umbrella, in a way that
> would make life easier for other projects too.

That seems indeed a good idea to have a sub repo for the tools but, for the
short term, where should I put my fwumdata tool TF-A or U-boot?

Regards,
-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com