[U-Boot] [PATCH] ARM: Add support for edb93xx boards

[Matthias Kaehlcke <matthias@kaehlcke.net>]

Hello Wolfgang,

El Tue, Dec 08, 2009 at 12:51:47AM +0100 Wolfgang Denk ha dit:

> > > U-Boot uses assembler only when ther eis no reasonable way to
> > > implement the code in C, and I don't see any such justification here.
> > > Please rewrite all this in C.
> > 
> > i'm just starting to get my feet wet with low level initialization and
> > supposed sdram setup is always done in assembler.
> 
> There is no reason for assembly. We almost always do this in C.

i am starting to look at this issue and it seems i need some more guidance:

before relocating U-Boot to RAM for ARM920T processors a jump to the
label *lowlevel_init* is performed, where RAM timings are supposed to
be set up. in the patch i sent these operations are performed in
assembly and you asked me to rewrite them in C.

i'm relativly new to low-level setup, so i apologize if the following
question sounds plain stupid to you: is C really available at this
point? if my interpretation of the code in cpu/arm920t/start.S is
correct, C code starts at start_armboot, after relocation of
U-Boot. and after that point i'd think it's to late to change RAM
timings as U-Boot is running from RAM.

could you please give some advice to clear my confusion and maybe
provide a pointer to a board/cpu which handles low-level setup in
the intended way?

thanks

-- 
Matthias Kaehlcke
Embedded Linux Developer
Barcelona

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