[U-Boot] [PATCH v5 1/3] arm: spl: Fix SPL booting for OMAP3

[Albert ARIBAUD <albert.u.boot@aribaud.net>]

Hi Tom,

On Wed, 3 Jul 2013 15:47:27 -0400, Tom Rini <trini@ti.com> wrote:

> On Thu, Jun 27, 2013 at 10:27:26AM +0200, Albert ARIBAUD wrote:
> > Hi Stefan,
> > 
> > On Tue, 25 Jun 2013 09:14:12 +0200, Stefan Roese <sr@denx.de> wrote:
> > 
> > > Fix a problem with a re-assignment of r8 in the SPL version.
> > > 
> > > This patch now moves the call to s_init() to a later stage, right before
> > > calling board_init_f(). And makes sure that r8 is correctly initialized
> > > before s_init() is called. r8 now is only written in crt0.S.
> > > 
> > > This error was detected on the SPL port for the Compulab CM-T35 board
> > > (OMAP3530).
> > > 
> > > Signed-off-by: Stefan Roese <sr@denx.de>
> > > Cc: Tom Rini <trini@ti.com>
> > > Cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
> > > ---
> > > Albert, I'm not really happy with this patch as it evolves now. As you
> > > will see, I had to make some further additions to crt0.S to fix a
> > > problem for non-SPL builds and to fix compilation errors for non-OMAP
> > > platforms. This gets quite ugly now. Looking back at my patch v1, this
> > > looks much less intrusive.
> > > 
> > > What do you think?
> > 
> > I said the first patch was NAK, and the reasons I NAKed it remain.
> > 
> > However, there might be another solution: instead of squeezing the
> > call to s_init() in crt0.S right between the initial environment
> > setting and the call to board_init_f(), we could simply move the
> > s_init() call inside board_init_f().
> > 
> > From a running conditions perspective, the only change would be that
> > s_init() is going to run from a non-empty stack, but we know that there
> > is free stack enough during board_init_f() to call functions.
> > 
> > Moving the call to s_init() into board_init_f() removes any changes to
> > crt0.S, which were my essential NAK reason and saves you some ugliness.
> > 
> > I would even hazard that you could place s_init in init_sequence[], for
> > instance as a first entry to be called (before arch_cpu_init). After
> > all, the only difference in execution is that gdata is going to be
> > initialized properly before s_init() kicks in.
> > 
> > Also, a name change would be in order, because s_init() as a private
> > OMAP function is ok, but as an init function invoked from board_init_f()
> > it needs a more meaningful name.
> 
> So, this is one of the things that needs resolving for v2013.07.  What
> do you want to call the renamed s_init function?  I think we need to go
> the init_sequence route, and keep common/board_f.c in sync (I did a
> trivial test the other week about moving am335x into the generic board
> framework and it went fine, so I'll want to move all the TI boards I can
> over soon).  Thanks!

I have no strong opinion on the name... As is does mux and clock inits
needed by the 'system' (which for all I know may well be where the "s"
of s_init comes from), we could simply name it system_init().

Amicalement,
-- 
Albert.