[U-Boot-Users] u-boot debug suggestions

[U-Boot-Users] u-boot debug suggestions

[Don Pruitt]

Hi,

I have a custom board running a 405GPr that is based off of the  
walnut ref board with the exception that we have a 512KB boot prom  
starting @ fff80000 which is where I burn uboot. I have ported u- 
boot-1.1.3 to the board with the assistance of a BDI2000 which seems  
to work well. I get the uboot UI and am able to read and write to  
sdram and flash, however if I remove the jtag uboot crashes at  
startup.  My first thought was that it's a timing issue as the jtag  
would hold the board in reset on power up.  I questioned this when I  
discovered that  I can somewhat simulate this with the BDI2000 by  
issuing a reset run 1000. This approach would seem to indicate that  
it is crashing when attempting to access an sdram address.  What I  
don't understand is why there would be a difference with the sdram  
initialization between powering up the target and issuing a bdi  >go  
and issuing a >reset run xxxx?  Any suggestions you have would be  
greatly appreciated!


thanks,

Don Pruitt

[U-Boot-Users] u-boot debug suggestions

[Wolfgang Denk]

In message <DA75F432-477C-4145-B022-FDCCA1A5C6BE@alltel.net> you wrote:
> 
> discovered that  I can somewhat simulate this with the BDI2000 by  
> issuing a reset run 1000. This approach would seem to indicate that  
> it is crashing when attempting to access an sdram address.  What I  

No, not at all. "Reset run" just skips all the statements in  the  init
section of the BDI2000 config file. It seems that one of more of them
are  vital  for  successfully  booting U-Boot on your board, and that
these are missing / different in your port of U-Boot.

> don't understand is why there would be a difference with the sdram  
> initialization between powering up the target and issuing a bdi  >go  
> and issuing a >reset run xxxx?  Any suggestions you have would be  
> greatly appreciated!

I really cannot follow you why you think this has anything to do with
the SDRAM initialization; it can  be  any  other  part  of  the  init
sequence as well. Check your init section in the BDI config file, and
remove it step by step, and you will soon see what's missing / wrong.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Anyone who isn't confused here doesn't really know what's going on.

[U-Boot-Users] u-boot debug suggestions

[Stefan Roese]

Hi Don,

On Sunday 20 November 2005 21:51, Don Pruitt wrote:
> I have a custom board running a 405GPr that is based off of the
> walnut ref board with the exception that we have a 512KB boot prom
> starting @ fff80000 which is where I burn uboot. I have ported u-
> boot-1.1.3 to the board with the assistance of a BDI2000 which seems
> to work well. I get the uboot UI and am able to read and write to
> sdram and flash, however if I remove the jtag uboot crashes at
> startup.

Where excatly does it crash? Please send a bootlog.

What SDRAM configuration do you use? Do you have a DIMM module on your board 
and use the spd_sdram code. Or do you use hardcoded SDRAM init values?

Best regards,
Stefan