[U-Boot-Users] [PATCH v2] PPC405EX(r) ECC and SDRAM Initialization Clean-ups

[Stefan Roese]

On Tuesday 29 April 2008, kenneth johansson wrote:
> > > Stefan already asked this... I would also like to understand why the
> > > data cache cannot be used for initial RAM as we do on so many other
> > > systems?
> >
> > Agreed. The changes were based on the comments in the Kilauea and Makalu
> > board ports indicating that this had been attempted--twice--and didn't
> > work.
> >
> > I am escalating with AMCC to find out if this is a processor errata,
> > board issue or just a programming issue that needs to be investigated
> > further.
>
> The cache trick works fine on 405CR/405GP. Is the cache redesigned for
> 405EX. Why would they still call it a 405 if the core was redesigned?

I already sent an update to Grant privately on this. Here again:

The main problem is that the board crashes with an exception (0x200: Data 
machine check) when init RAM in dcache is used. This happens upon calling 
trap_init() in board_init_r(). The exception must be pending and 
is "activated" upon the trap_init() call. Either Grant (or somebody else?) 
will look into this, or I will try to look into is (again) in a few days.

Thanks.

Best regards,
Stefan

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