[U-Boot-Users] LinuxPostMortemAnalysis only smells like DEADBEEF

[robert lazarski]

On Nov 13, 2007 2:09 PM, Clemens Koller <clemens.koller at 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