Re: [Xenomai-help] kernel 2.6.32.11 with xenomai 2.5.3 fails to boot on ubuntu lucid system

[Philippe Gerum <rpm@xenomai.org>]

On Tue, 2010-08-17 at 12:27 +0200, Philippe Gerum wrote:
> On Mon, 2010-08-16 at 21:14 +0200, Theo Veenker wrote:
> > On 08/16/2010 04:26 PM, Theo Veenker wrote:
> > > Gilles Chanteperdrix wrote:
> > >> Theo Veenker wrote:
> > >>> Hi,
> > >>>
> > >>> I want to upgrade all our PC's from Ubuntu hardy to lucid and in the
> > >>> process
> > >>> I'm also going from kernel 2.6.29.5 with Xenomai 2.4.8 to kernel
> > >>> 2.6.32.11
> > >>> with Xenomai 2.5.3.
> > >>>
> > >>> I first built and tested the 2.6.32.11 kernel with 2.5.3 on my hardy
> > >>> system
> > >>> and all went fine. But the problem is it just doesn't run on the
> > >>> lucid distro.
> > >>
> > >> This, I do not understand, the kernel does not need any support from the
> > >> distribution for booting, how can the same kernel boot with one
> > >> distribution, and not with the other? When you say the "same kernel", do
> > >> you mean the exact same zImage or bzImage, or do you mean the kernel
> > >> with the same configuration, but with a different compiler, or only the
> > >> version is identical?
> > >>
> > >
> > > It is a complete mystery to me either. I compiled my kernel into a deb
> > > package
> > > and installed the very same deb package on three machines:
> > > MSI p45 neo3 with Hardy on it -> works OK
> > > MSI p45 neo3 with Ludid on it -> nothing (works fine with regular kernel)
> > > MSI 945P with Lucid on it: -> nothing (works fine with regular kernel)
> > >
> > > I'll try the suggestions posted and keep you informed.
> > 
> > OK. Connected a terminal to catch early kernel messages. Still no output
> > unfortunately (with the regular kernel I do get output on the terminal,
> > so the connection works).
> > 
> > Meanwhile also built and tested kernel 2.6.32.15 + xenomai 2.5.4. Still nothing.
> > I'm clueless. I'm running Xenomai for years on dozens of systems and I've
> > never run into problems like this. I think I'll have to sit down and take a
> > close look at what I'm doing. I've always built my kernels using make-kpkg,
> > maybe that somehow introduces a problem here. I'll try without it.
> > 
> > (unfortunately/luckily I have to work from home for a few days so I can't
> > get to the test system until later this week)
> 
> I failed to reproduce the issue yet, but it very much looks like an
> I-pipe bug. Could you try the following config variants when time
> allows:
> 
> - on 2.6.32.11 or .15, disable CONFIG_SMP, enable CONFIG_X86_UP_APIC
> only (*).
> - on 2.6.32.11 or .15, disable CONFIG_SMP, enable CONFIG_X86_UP_APIC and
> CONFIG_X86_UP_IOAPIC (*).
> - on 2.6.32.7, use your normal CONFIG_SMP config, with this patch in:
> http://download.gna.org/adeos/patches/v2.6/x86/older/adeos-ipipe-2.6.32.7-x86-2.5-01.patch
> 
> (*) you need to switch off CONFIG_SMP first, to see those knobs appear
> in the "processor type and features" menu.

I forgot another important switch: make sure to disable CONFIG_XENOMAI
completely in your kernel config, only keeping CONFIG_IPIPE, or at least
to compile out all skins. When the first skin is started, our real-time
timer starts ticking, and we don't want the relevant code in the way
while chasing the original issue.

> 
> The fact that you did see the panic blinking signal at least once tends
> to point the finger at some access fault the kernel tries to recover
> without success, rather than a sudden freeze. It must happen early
> enough during the boot process, for the console not to be available yet
> for reporting what the kernel whines about.
> 
> We don't know yet if that bug is either the consequence of some
> interrupt delivery, and/or induced by code only involved in SMP. Those
> test configs may help in discovering this.
> 
> TIA,
> 

-- 
Philippe.