[U-Boot] [PATCH 18/42] Blackfin: make sure autoconf.mk is generated early enough

[Wolfgang Denk]

Dear Mike Frysinger,

In message <200902101449.24108.vapier at gentoo.org> you wrote:
>
> > > > > +	@$(MAKE) -s -B $(obj)include/autoconf.mk
> > > > > +	@$(MAKE) -s -B $(obj)include/autoconf.mk
> > > >
> > > > Do you really mean to do this twice?
> > >
> > > unfortunately, yes.  since some settings in the board config are turned
> > > into compiler flags and those compiler flags can in turn affect the board
> > > config, we need to do it twice.  first is to make sure the proper cpu
> > > flags are propagated into the toplevel build env while the second is to
> > > make sure the autoconf.mk fully reflects the board config.
> >
> > Sounds like a design problem to me.
>
> not really.  the point is to avoid duplication and considering the method to 
> attain that, sounds pretty good to me.

Well, no othe rarchitecture seems to need that,  and  it  looks  very
strange.  I guess 4 out of 5 persons who will see this are tempted to
"clean this up".

> > That would be the minimum, but given the  fact  that  the  top  level
> > Makefile  already includes rules to build autoconf.mk I really wonder
> > if we must do this so often, and if so, then why  this  is  only  the
> > case for blackfin.
>
> the top level Makefile includes rules to build it, but it doesnt re-source it 
> once it's been generated.  so anything in the top level cannot use things from 
> autoconf.mk (like $(arch)_config.mk).

To me it seems as if you were rebuilding it twice without re-sourcing
it inbetween, too.

And you fail to explain why BF needs this, while all other
architectures don't.

Best regards,

Wolfgang Denk

-- 
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