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

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

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.

Amicalement,
-- 
Albert.