On Thursday 30 April 2009, Jonathan Haws wrote:
I am certain that it is a hardware failure that is causing the machine check because I can use the exact same binary on another (identical)
board
and have it boot just fine. That tells me that all the EBC and SDRAM settings are correct;
From my experience you can't be sure that SDRAM setting are "currect" at this stage.
Would that be the case on our other 6 boards then? We have 6 boards that are up and running with the exact same U-Boot binary file. If there was a problem with the SDRAM settings on one board, would not the other board show the same symptoms? That is the reason why I have not dug deeper into the SDRAM initialization. However, I will take your advice and do so, because if there is a problem there, then the other boards may be experiencing problems, just not to the extent that this one is.
and that I am using the right addresses and chip selects for the data cache.
Currently I am leaning toward an SDRAM problem because I get about a 20 second pause when U-Boot tries to relocate to RAM.
Yes, I'm pretty sure that you have some SDRAM related problems. Either configuration is non-optimal, or even (perhaps more unlikely) a hardware problem. I suggest that you re-check the DDR2 autocalibration (method A & B).
Thanks for confirming my initial hunch - problem lies in SDRAM. I will let you know what I find - whether it is a hardware or software problem.
One thing I may mention is that we had the SDRAM chips re-balled before they were mounted on the board. Maybe something went wrong during that process on these chips on the problem board - who knows.
Anyway, once I get this resolved I will post the solution.
Thanks all!
Jonathan