BigSur: garbled characters during boot

BigSur: garbled characters during boot

[Martin Michlmayr]

When I boot a current kernel from git on a BigSur board I get some
garbled characters:

Synthesized TLB store handler fastpath (31 instructions).
Synthesized TLB modify handler fastpath (30 instructions).
��͡�х�������ɥ��遚����Bzɑ��遪b�������ѕͥ5R�Inode-cache hash table entries: 16384 (order: 4, 65536 bytes)
Memory: 250436k/257568k available (2561k kernel code, 6940k reserved, 826k data, 132k init, 0k highmem)
Mount-cache hash table entries: 512

Any idea what this might be?
-- 
Martin Michlmayr
http://www.cyrius.com/

Re: BigSur: garbled characters during boot

[Atsushi Nemoto]

On Sun, 25 Nov 2007 13:48:42 +0100, Martin Michlmayr <tbm@cyrius.com> wrote:
> When I boot a current kernel from git on a BigSur board I get some
> garbled characters:
> 
> Synthesized TLB store handler fastpath (31 instructions).
> Synthesized TLB modify handler fastpath (30 instructions).
> ��͡�х�������ɥ��遚����Bzɑ��遪b�������ѕͥ5R�Inode-cache hash table entries: 16384 (order: 4, 65536 bytes)
> Memory: 250436k/257568k available (2561k kernel code, 6940k reserved, 826k data, 132k init, 0k highmem)
> Mount-cache hash table entries: 512
> 
> Any idea what this might be?

Do you enable EARLY_PRINTK?  If so, this might be the console-handover
issue.  On the handover, "console handover: boot ..." message will be
printed both early console and new console.  If they were same device,
drivers might be confused.

IIRC Maciej have tried to fix this issue a while ago on LKML.

---
Atsushi Nemoto

Re: BigSur: garbled characters during boot

[Martin Michlmayr]

* Atsushi Nemoto <anemo@mba.ocn.ne.jp> [2007-11-25 22:28]:
> Do you enable EARLY_PRINTK?

Yes.

> IIRC Maciej have tried to fix this issue a while ago on LKML.

Right, I think I remember that discussion.  Did anything come out
of it?
-- 
Martin Michlmayr
http://www.cyrius.com/

Re: BigSur: garbled characters during boot

[Maciej W. Rozycki]

On Sun, 25 Nov 2007, Martin Michlmayr wrote:

> > IIRC Maciej have tried to fix this issue a while ago on LKML.
> 
> Right, I think I remember that discussion.  Did anything come out
> of it?

 The exact mess encountered is specific to the chip/board used.  I haven't 
seen too much of clutter on my SWARM, so I just disregarded the issue.  
If this is found problematic, I may have a look at the driver to see if 
anything can be done.  At least CFE sources are available, so if it turns 
out to be an issue there, it can be fixed too.  All the relevant registers 
in the DUART are r/w, so the state can easily be examined and preserved if 
need be.

 But please feel free to complain to the author of the change -- I am not 
sure if the amount of breakage throughout systems is justified by the gain 
from the additional message.  And there may be a way to implement it in a 
less intrusive way.

  Maciej

Re: BigSur: garbled characters during boot

[Thomas Bogendoerfer]

On Sun, Nov 25, 2007 at 10:28:03PM +0900, Atsushi Nemoto wrote:
> Do you enable EARLY_PRINTK?  If so, this might be the console-handover
> issue.  On the handover, "console handover: boot ..." message will be
> printed both early console and new console.  If they were same device,
> drivers might be confused.

it will not be printed on both consoles, but while early console is
active the real console driver does things to the serial chip,
which might confuse the early console driver/prom.

> IIRC Maciej have tried to fix this issue a while ago on LKML.

this didn't work out for ip22zilog, so I digged through the mess. I
solved the problem by setting up the chip in one go. Before there
was some chip setup during probing, which killed prom_putchar().

Thomas

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