[U-Boot-Users] Freescale MPC8349EMDS hang on boot

Ira Snyder
2008-07-18T17:28:57Z

On Fri, Jul 18, 2008 at 07:59:36AM -0400, Jerry Van Baren wrote:
>
> Hi Ira,
>
> This is a long shot, but could there be a problem with the DDR SDRAM
> and/or its initialization?

I suppose it could be, but this seems unlikely. Why would aligning the
start of a section to a 32 byte boundary make the ram initialization fail,
but any other alignment works?

Also, I have two nearly identical boards here. One is a MPC8349EMDS
Rev-3.1 (it's an EA board, using DDR2) and another, older MPC8349EMDS
Rev-1.1 (it's an E board, using plain DDR). Both fail in exactly the
same way.

> Are you using a factory-provided DIMM? What
> if you try a different one (preferably a different brand/size)?
>

Yes, both boards have the factory provided memory. There are different
DIMMs on each of the two boards. The DDR is Micron, the DDR2 I don't
recognize the manufacturer for. Hopefully they're different enough.
Unfortunately, I don't have any more memory that fits these boards.

> I'm not familiar with the board configuration, I presume instruction
> caches are enabled. Are data caches enabled too? What happens if you
> disable cache(s)?
>

Yes, both caches are enabled. I'm not really sure how to turn them off
without effecting the bootup sequence. It looks like they are assumed to
enabled during parts of startup in cpu/mpc83xx/start.S

I checked include/configs/MPC8349EMDS.h and didn't find any obvious
config options for disabling the cache.

The hang happens before the relocation to RAM. The "I2C:" line where it
hangs is printed before the relocation. There are "SPI:" and "DRAM:"
lines that should also be printed before the relocation to RAM.

> Best regards,
> gvb

As some added information, I tried building with ELDK-4.1 (rather than
ELDK-4.2, which I have been using) and was unable to get the lockup.
However, in the past I did get several similar lockups using ELDK-4.1,
which went away when I upgraded to ELDK-4.2 (the problems prompted the
upgrade). Unfortunately, I just thought the problem was my code at the
time, and so I did not keep any images around.

Thanks for your help,
Ira