Re: Apparent kernel bug with GDB on ppc405

Grant Likely
2007-10-24T20:46:23Z

On 10/24/07, Matt Mackall <mpm@selenic.com> wrote:
> On Wed, Oct 24, 2007 at 02:28:14PM -0600, Grant Likely wrote:
> > On 10/24/07, Matt Mackall <mpm@selenic.com> wrote:
> > > I'm trying to debug a trivial statically-linked hello world program on
> > > a Xilinx PPC 405 and I'm seeing the following behavior:
> > >
> > <snip>
> > >
> > > Any suggestions?
> >
> > http://thread.gmane.org/gmane.linux.ports.ppc.embedded/11202
> >
> > I was fighting with a similar problem almost 2 years ago. Looks like
> > it might be related. At some point the problem seemed to go away and
> > I determined what the root cause was. :-(
> >
> > I haven't been using gdb lately, so I don't know if it's the same
> > problem. Nobody I had talked to had seen the issue on other 405
> > platforms. It could very well be something virtex-specific.
>
> Could be the same problem, but I'm seeing only your symptom 3 so far.
>
> I've tried throwing some larger hammers at the problem. Flushing all
> of the dcache and icache (flush_dcache_all and
> flush_instruction_cache) isn't helping. But printk(".") does!

It's really true; printk *is* the most valuable tool kernel hackers
have for debugging.

g.

--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
grant.likely@secretlab.ca
(403) 399-0195