Re: Devicetree Maintenance in barebox

[Jean-Christophe PLAGNIOL-VILLARD <plagnioj-sclMFOaUSTBWk0Htik3J/w@public.gmane.org>]

On 09:10 Fri 07 Feb     , Jason Cooper wrote:
> Hi Sascha,
> 
> + Grant Likely, Ian Campbell, devicetree ML
> 
> This discussion started on the barebox bootloader mailinglist
> 
> On Fri, Feb 07, 2014 at 08:13:32AM +0100, Sascha Hauer wrote:
> > It's becoming more obvious that devicetree maintenance is painful
> > because we have to sync them to the kernel regularly. My hope was that
> > this would get simpler once the devicetrees get their own repository
> > outside the kernel, but it seems that won't happen anytime soon.
> 
> hmm.  Ian Campbell has a tree he is working on:
> 
>   git://xenbits.xen.org/people/ianc/device-tree-rebasing.git
> 
> Also, In the DT meeting earlier this week, Grant Likely said he has the
> request in to create a separate mailinglist for collaboration between
> the different devicetree users (BSD, Linux, etc).
> 
> > So my current idea to continue with barebox devicetrees is:
> > 
> > - Maintain a kernel branch which has all devicetree changes we need in
> >   barebox in a clean step-by-step series
> > - rebase this branch regularly on the newer kernel
> > - Copy the resulting devicetrees to barebox
> > 
> > The upside is that we have up to date devicetrees in barebox without
> > having to resync them by hand on a per SoC basis.  Of course this also
> > means that we lose the devicetree history and breakage may be introduced
> > with some huge commits saying "Update devicetrees to Linux-3.x".
> > 
> > Any better ideas? I think we have to do something.
> 
> I think the proper solution will percolate out of the first
> cross-project discussions on the new ML.
> 
> imho, the goal is to not have any project tied to a specific version of
> the devicetree.  iow, we don't break backwards compatibility in the
> devicetrees, and projects should revert to default behavior if new dt
> parameters are missing.  This means Linux and BSD shouldn't need to keep
> a current copy of the devicetree in their trees.  However, building the
> bootloader is a different animal.  It needs to provide the dt blob...
> 
> Definitely fodder for the new ML.
> 
> Grant, can you please add Sascha to the list of folks to notify when the
> new ML is ready?

Yes we do need to split the DT ASAP

Best Regards,
J.
> 
> thx,
> 
> Jason.
> 
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