[U-Boot] MPC8536 problems

[David Lynch Jr.]

I am bringing u-boot-2009.03-rc1 up on an MPC8536 target, and I am
having some problems reading DDR, suggestions would be greatly
appreciated. 
I am using this particular u-boot, because the client succeeded in
getting that working on an MPC8536DS (that I do not have access to). I
can not even get the serial port working on the target with newer
versions of u-boot. 
This target is much simpler than the MPC8526DS and I have disabled
everything but Serial, DDR, and NOR in the board configuration file. The
only thing that must work is booting linux. This board has no PIXIS, no
ISC307, and the DDR does not have SPD.  
I now appear to have everything but DDR working. I can not get u-boot to
relocate to ram. Writing to RAM seems to work - in the sense there are
no faults and writes do not hang, but reading RAM stalls the instruction
forever without error. 
I am using a BDI3000 - which I am not fluent in. The BDI3000
configuration is minimal - only enough to read/write/erase NOR, and
manipulate the processor. The BDI3000 faults when reading DDR - but it
is not setup for that. 
The MPC8536DS code to setup DDR without SPD would not compile as it was,
but I beleive I have fixed that. I have played with myriads of DDR
controller register value changes without change in behavior. As this is
a total read failure - rather than just unreliable operation I am
leaning towards looking for other culprits - though the DDR
configuration is still high on the list as u-boot works ont he
development system and the remaining difference of consequence is that
the DDR is manually programmed on the target. 
Access to the hardware is severely limited - it is two hours away in a
secure facility, and I must try as much as possible during the limited
time I have access. 





-- 
Dave Lynch                                                  DLA Systems
Software Development:                                    Embedded Linux
717.587.7774           dhlii at dlasys.net    http://www.dlasys.net
Over 25 years' experience in platforms, languages, and technologies too
numerous to list.

"Any intelligent fool can make things bigger and more complex... It
takes a touch of genius - and a lot of courage to move in the opposite
direction."
Albert Einstein