kernel dump solutions

kernel dump solutions

[Josh Boyer]

Hi All,

I'm curious what people are using for a kernel dump solution on embedded
platforms.  It seems that kexec/kdump is the default solution for
desktop and server machines, but this seems to be a bit heavy for
embedded platforms.  Requiring a second kernel to do the dump seems like
a cost that most platform designers wouldn't be willing to incur.

The only other alternative that I'm aware of is LKCD.  It doesn't seem
particularly active at all these days.  Mcore has been sufficiently dead
for years.  So what's left?  What else are people using?

josh

Flatten device tree & PPC linux

[Fundu]

i was reading this ...
http://free-electrons.com/kerneldoc/latest/powerpc/booting-without-of.txt
and was wondering if the kernel 2.4(yes 2.4) expects a flatten device tree ?

Anybody any ideas ? 
TIA !


--- On Wed, 8/13/08, Josh Boyer <jwboyer@gmail.com> wrote:

> From: Josh Boyer <jwboyer@gmail.com>
> Subject: kernel dump solutions
> To: linux-embedded@vger.kernel.org
> Date: Wednesday, August 13, 2008, 12:48 PM
> Hi All,
> 
> I'm curious what people are using for a kernel dump
> solution on embedded
> platforms.  It seems that kexec/kdump is the default
> solution for
> desktop and server machines, but this seems to be a bit
> heavy for
> embedded platforms.  Requiring a second kernel to do the
> dump seems like
> a cost that most platform designers wouldn't be willing
> to incur.
> 
> The only other alternative that I'm aware of is LKCD. 
> It doesn't seem
> particularly active at all these days.  Mcore has been
> sufficiently dead
> for years.  So what's left?  What else are people
> using?
> 
> josh
> 
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Re: Flatten device tree & PPC linu

[Grant Likely]

On Wed, Aug 13, 2008 at 11:44 PM, Fundu <fundu_1999@yahoo.com> wrote:
> i was reading this ...
> http://free-electrons.com/kerneldoc/latest/powerpc/booting-without-of.txt
> and was wondering if the kernel 2.4(yes 2.4) expects a flatten device tree ?

No, 2.4 does not support flattened device trees.  It is a 2.6 thing
for arch/powerpc.

g.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.

Re: Flatten device tree & PPC linu

[David VomLehn]

Grant Likely wrote:
> On Wed, Aug 13, 2008 at 11:44 PM, Fundu <fundu_1999@yahoo.com> wrote:
>> i was reading this ...
>> http://free-electrons.com/kerneldoc/latest/powerpc/booting-without-of.txt
>> and was wondering if the kernel 2.4(yes 2.4) expects a flatten device tree ?
> 
> No, 2.4 does not support flattened device trees.  It is a 2.6 thing
> for arch/powerpc.

It came originally from the PowerPC world, but there is now Sparc implementation 
in the kernel tree. We're working on using device tree for MIPS and, according to 
a participant at the OLS Device Tree BOFS, someone in the ARM world is also 
working on an implementation. I don't know how much work it would be to backport 
to 2.4, but my guess is that it's pretty independent of the kernel version.

There is now a device tree mailing list independent of PowerPC. You can find more 
info at https://ozlabs.org/mailman/listinfo/devicetree-discuss

Re: kernel dump solutions

[Randy MacLeod]

On Wed, Aug 13, 2008 at 3:48 PM, Josh Boyer <jwboyer@gmail.com> wrote:
> Hi All,
>
> I'm curious what people are using for a kernel dump solution on embedded

Create a region of memory that pesist across resets.
Put kernel panic info, exceptiions and scheduling events into said memory.
Profit!

If only more manufactures would support this in the bios...
Intel and BIOS writter folks are you listening?


-- 
// Randy

Re: kernel dump solutions

[Josh Boyer]

On Thu, 2008-08-21 at 21:53 -0400, Randy MacLeod wrote:
> On Wed, Aug 13, 2008 at 3:48 PM, Josh Boyer <jwboyer@gmail.com> wrote:
> > Hi All,
> >
> > I'm curious what people are using for a kernel dump solution on embedded
> 
> Create a region of memory that pesist across resets.
> Put kernel panic info, exceptiions and scheduling events into said memory.
> Profit!

I've done that many times.  It works well enough, but it's not a dump.
I've actually used some dumps to debug some rather difficult kernel
problems in the past, but there are increasingly fewer options these
days.

> If only more manufactures would support this in the bios...
> Intel and BIOS writter folks are you listening?

BIOS... yeah... I don't have a BIOS.  That's the best way to deal with
that.

josh