On Nov 13, 2007 2:09 PM, Clemens Koller clemens.koller@anagramm.de wrote:
Hi!
I'm using an kernel 2.6.23.1 cuImage.85xx target and an u-boot from last week's git (which seems to work fine) on an mpc8540ads compatible board.
I just tried to follow: http://www.denx.de/wiki/view/DULG/LinuxPostMortemAnalysis because of no console output.
But no matter what address I try to figure out to dump __log_buf, it seems that u-boot wipes my memory during POST, so I cannot get anything @ __log_buf.
md 003b2ea8 (where my __log_buf points) 003b2ea8: deadbeef deadbeef deadbeef ........
I am pretty sure that only my console got stuck since my harddisks (on PCI) seems to get initialized (some noise and led activity from the HDDs) and the system reboots automatically after approx. 180 seconds due to the usual minor problems.
So, there are some questions:
Is u-boot wiping my memory during POST?
How can I disable that?
What are the default console settings to get a console on ttyS0?
Regards,
Clemens Koller __________________________________
Hi Clemens, maybe I can help you this time ;-) . I just so happen to be running 85xx / 2.6.23 / latest u-boot also have serial port problems - though in my case its intermittent. I've been able to get output once every 20 times or so. However, I can always get the messages from "__log_buf" . In my case, my log buf is 2a0f24 . So I execute:
=> md 2a0f24 700
deadbeef is the magic value from u-boot that is used to init memory, and 003b2ea8 doesn't seem right considering I'm using the same kernel.
As for my problems, I'm waiting for my hardware guys to give me a second serial port to try out kgdb. I've been using just printk's for now, but I just got my bdi back so I might know more soon. Maybe we could help each other.
HTH, Robert