Re: Devicetree Maintenance in barebox

[Alexander Shiyan]

Пятница,  7 февраля 2014, 9:47 +01:00 от Sascha Hauer <s.hauer at pengutronix.de>:
> On Fri, Feb 07, 2014 at 11:39:33AM +0400, Alexander Shiyan wrote:
> > Hello.
> > 
> > Пятница,  7 февраля 2014, 8:13 +01:00 от Sascha Hauer
> <s.hauer at pengutronix.de>:
> > > Hi All,
> > > 
> > > 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.
> > > 
> > > 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.
> > 
> > As far as I know, in the community have any thoughts on the transfer of the
> DT data
> > in a separate project, but most likely it will not be soon ...
> 
> Yeah, I also don't think this will happen soon. Even if it does I think
> this won't solve all problems. We will still need barebox specific
> adjustments.
> 
> > 
> > At the moment, I want to suggest to use only non-modified DT files, i.e.
> barebox
> > should use to build their own files, which include the original data from
> the kernel.
> > 
> > Just for example:
> > # ls
> > bb_<board.dts>
> > <board.dts>
> > 
> > # cat bb_<board.dts>
> > 
> > #include "<board.dts>"
> > /* All overrides here */
> > chosen {
> >   ...
> > };
> 
> I like the idea. One disadvantage may be that the structure in the dts
> directory gets more unclear, but I guess we can't have everything.

We can store our (bb-only) DTS content in a separate place
and keep kernel dts directory clean.

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