TLB Miss booting linux kernel on ppc 405

Ricardo Ayres Severo severo.ricardo at
Thu Feb 14 05:49:36 EST 2008

Executing without single step the exception doesn't occurs. But at
__log_buf I get only trash, even after reseting the processor.
How can I send some characters to uartlite on asm code?


On Feb 13, 2008 4:32 PM, David Baird <dhbaird at> wrote:
> On Feb 13, 2008 11:03 AM, Ricardo Ayres Severo <severo.ricardo at> wrote:
> > Here are the srr dump:
> >   srr0: c0002218
> >   srr1: 00021030
> >   srr2: 00001154
> >   srr3: 00000000
> Okay, SRR0 tells us that you did in fact have an exception at
> 0xc0002218.  And I am willing to bet that is the line you mentioned
> (line 826 of start_here).  You can match this up with your
> or an objdump -d of vmlinux.
> Someone who knows more than I do can correct me on this, but I have a
> suspicion.  As soon virtual (translation) mode is entered, I have had
> a hard time using the normal debugging functions (e.g. single
> instruction stepping and reading memory regions).  While in virtual
> mode, it seemed like I had to resort to these techniques:
> - Blinking some LEDs
> - Spitting characters out of a uartlite
> - When an exception occurs, the processor switches back into real mode
> and therefore I can set breakpoints on the beginnings of various
> exception handlers and be able to use normal debugging tools again
> So, I have another question.  Can you set a breakpoint on 0x1100 (in
> XMD: bps 0x1100 hw), then just let it run (i.e. do not single step!)
> all the way until an exception happens.  When the exception happens,
> can you then paste the SRR0, SRR1, and the ESR (exception syndrome
> register)?
> I hope I am not giving you a run-around here....
> -David
> _______________________________________________
> Linuxppc-embedded mailing list
> Linuxppc-embedded at

Ricardo Ayres Severo <severo.ricardo at>

More information about the Linuxppc-embedded mailing list