Re: [PATCH 0/5] ARM: orion5x/dove/mv78xx0 multiplatform

[Jason Cooper <jason@lakedaemon.net>]

On Fri, Dec 11, 2015 at 03:46:53PM +0100, Arnd Bergmann wrote:
> On Friday 11 December 2015 13:36:01 Jason Cooper wrote:
> > +Josh
> > 
> > Hey Arnd, Detlef,
> > 
> > On Fri, Dec 11, 2015 at 12:10:55AM +0100, Arnd Bergmann wrote:
> > > On Thursday 10 December 2015 23:00:24 Detlef Vollmann wrote:
> > > > On 12/10/15 22:29, Arnd Bergmann wrote:
> > > > > On Thursday 10 December 2015 22:14:25 Detlef Vollmann wrote:
> > > > >> On 12/10/15 21:59, Arnd Bergmann wrote:
> > > > > It may also be worth investigating what has made CONFIG_OF so costly,
> > > > Probably because too much is done at runtime and too few things can
> > > > be fixed at build time.
> > > > 
> > > > > maybe we can reduce this a bit again.
> > > > Probably not without turning the wheel backward 
> > > > 
> > > > So for the test: yes it works, but I'm unhappy with it.
> > > 
> > > I'm not too happy about adding 80kb to the uncompressed kernel 
> > > image either. I've spent some more time now trying to find where
> > > we added the bloat. It's mainly in drivers, not in arch specific
> > > code, a kilobyte here and there eventually adds up, but the largest
> > > portion with a little over 50% of the total diff is drivers/of.
> > 
> > Wasn't there an idea kicked around a while ago to create a
> > dt2boardfile script/executable*?  Then, during kernel configuration, you
> > enable it and select which dts file you want.  It would disable
> > CONFIG_OF, multiplatform, etc.  And generate a board_file.c from the dts
> > file.
> 
> I think you are right this has come up in the past, but I don't see how
> it would work in practice without significant changes to driver subsystems:
> 
> The way we describe devices in DT is often very different from what we
> have for the traditional board files, and in some cases we don't even
> support platform data any more, so this would still depend on having
> properties according to the DT bindings, and require a large chunk of
> the same code that is doing DT at the moment.

yes, that's unfortunate.  Perhaps the tinification links are still
helpful to Detlef.

thx,

Jason.