[U-Boot] mpc8313 SPL, relocate_code, large page NAND

[Joakim Tjernlund]

>
> On Tue, 20 Apr 2010 10:36:08 +0200, Peter Vollmer
> <pvollmer-u-boot at innominate.com> wrote:
>
>
> > I then inserted 8 pairs of lwzu/stwu inside the loop to see when exactly
> > the problem occurs:
> >
> > 1: lwzu    r0,4(r8)
> >     stwu    r0,4(r7)
> >     lwzu    r0,4(r8)
> >     stwu    r0,4(r7)
> >     ...
> >     lwzu    r0,4(r8)
> >     stwu    r0,4(r7)
> >     bdnz    1b
> >
> > and the last breakpoint location that would get hit is after 6 times of
> > lwzu/stwu.
>
> Further testing showed that after 7 consecutive stwu r0,4(r7) instructions
> alone the problem already occurs, i.e. it seems to have nothing to do with
> the local bus controller, but with DDR RAM access, right ?

Probably a BDI2000 issue. If memory serves right BDI2000 flushes the cache
when it hits a BP.

Try this addin this to your BDI .cfg file:
TSZ4    0xe6000000   0xe60001100 ; init stack space for cache
; needs a 'sap 0' in BDI

Then reboot BDI 2000, telnet to it and enter "sap 0" at the cmd prompt.
Start debugging.

Don't ask me what it does though. I got this tip long time ago from Abatron

  Jocke