Linux 2.4.4 on 860 custom board

Linux 2.4.4 on 860 custom board

[Elan Feingold]

Hi,

I'm still trying to get Wolfgang's Linux 2.4.4 to come up on my custom 860
board.  I started with a bootrom that normally boots VxWorks, so I thought
I'd have no problem.  The IMMR is at the right place (0xff000000), and in
general the kernel boots up fine, but it dies with a "kernel access of bad
area" where the actual address is question is usually strange (e.g.
0x40000004, or 0x00000004).  It seems like it dies when it's trying to
access data, either kmalloc()ed or static, and it's never consistent where
it dies.  Sometimes it's inside a printk() where the print is trying to
print out some member of some structure.  And sometimes it does until it
mounts my root file system via NFS and then does the same oops down in the
NFS code.  Generally just very flaky!

I'd usually think it was a memory timing setup problem, right?  But VxWorks
runs fine, and has for years on the board.

Any ideas?  Is it possible that VxWorks just has less strict timing
requirements to run?

Best regards,

-elan


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Re: Linux 2.4.4 on 860 custom board

[Wolfgang Denk]

In message <NDBBLJKOJGKDOFBHNPGEMEIICEAA.elan@nxnetworks.com> you wrote:
>
> I'd have no problem.  The IMMR is at the right place (0xff000000), and in
> general the kernel boots up fine, but it dies with a "kernel access of bad
> area" where the actual address is question is usually strange (e.g.
...

Ummm...

> I'd usually think it was a memory timing setup problem, right?  But VxWorks

Maybe, but I don't think so here.

> runs fine, and has for years on the board.

For years? Which mask revision is your CPU, then? Did you enable  the
CPU6  bug  workaround  in  the kernel configuration for a try, and/or
disabled the data cache?

> Any ideas?  Is it possible that VxWorks just has less strict timing
> requirements to run?

Probably it does not use the MMU as much.

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
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