On 10/23/07, Jerry Van Baren gerald.vanbaren@ge.com wrote:
It sounds like your linux image is scribbling in flash, messing up u-boot (but not fatally). Do you have a flash file system configured in your linux image? Any other reason your linux image would overwrite flash? If you dump the end portion of the *flash* u-boot image before and after the successful linux boot, does it show corruption?
I never thoughtLinux might be corrupting FLASH memory for the following reasons:
1. When I load and run linux as a .bin file there is never any problem. Ah! yes, another good test would be to run load and run a linux .bin file (on a freshly programmed board) and after that try to inflate a packaged linux image. 2. Flash memory sectors where U-Boot resides are protected (read only). Could linux be removing the protection? I should check. 3. The problem occurs even when uncompressing from a RAM location to another RAM location, before linux has a chance to run. But obviously the corruption could still happen in the first run as you pointed out.
I will do as you suggest and compare the FLASH memory dump with my U-Boot image, it's a very good idea.
If that isn't the problem the follow up question is: what is the unexpected exception vector number 3, what is the meaning of the PC (where the exception occurred), what does the stack tell you when you dump it?
Yes, that's the hard part. I was hoping to aviod the hassle in case someone already encountered this problem and provided a patch (I couldn't find anything in previous postings though).
Thank you for your advice,
Erez