Jonathan Haws wrote: >> 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
1) Six boards work, one board fails. 2) SDRAM chips re-balled on the failing board. 3) SDRAM failing. That sounds like a hardware/assembly problem to me. My bet is a solder problem. Have you (can you) x-ray the chips and verify the SDRAM soldering is OK? Best regards, gvb _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot