Passes RAM test, but hangs at jumping to RAM

[Frank]

Sounds like you may have a signal integrety problem. try hanging
a scope on the address and data lines and look for transients...
--- SONE Takeshi <ts1 at cma.co.jp> wrote:
> On Thu, May 15, 2003 at 08:01:01AM -0600, ron minnich wrote:
> > On Thu, 15 May 2003, SONE Takeshi wrote:
> > 
> > > What could be a problem when it passes RAM test but hangs 
> > > immediately after jumping to RAM?
> > > 
> > > I'm developing a new raminit code and
> > > this happens only with a particular installation of DIMM.
> > > DIMM itself is not bad, it works when move to another
> slot,
> > > or another slot is filled with another DIMM.
> > > Award BIOS runs just fine with this DIMM installation.
> > 
> > Every time I've seen this it is either drive strength
> settings or timing 
> > (esp. on the 8601, it is VERY sensitive to buffer strength).
> 
> 
> I've found 0x6B is once asssigned the same value as Aword,
> then
> rewritten later with different value. (it's from CVS's
> raminit.inc)
> I thought this is something to do with drive strength (changes
> slew rate)
> but removing the latter one doesn't really change things.
> 
> I also tried COMFIG_COMPRESS=0, then Steve M. Gehlbach's
> copy-verify
> hack (found here:
>
http://www.clustermatic.org/pipermail/linuxbios/2002-October/000527.html
> ),
> and totally disabling cache.
> Everytime I change something, it stops execution at different
> point.
> 
> > You really need to dump the northbridge and make sure you
> know exactly, 
> > for each setting, why award set it one way and why linuxbios
> set it the 
> > same way or differently. This is very tedious but it is your
> only choice. 
> > With the 8601 I saw one case where all the bits except one
> were correct on 
> > a data read. It only takes on wrong bit, however, to wreak
> havoc.
> 
> Thanks. I'll again have to look at those hexadecimal dumps and
> the book.
> It really exhausts my eyes...
> 
> --
> Takeshi
> _______________________________________________
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> Linuxbios at clustermatic.org
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