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

[Stefan Kisdaroczi <kisda@domain.hid>]

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On 22.08.2010 19:42, Philippe Gerum wrote:
> On Wed, 2010-08-18 at 15:54 +0200, Stefan Kisdaroczi wrote:
>   
>> On 18.08.2010 14:11, Stefan Kisdaroczi wrote:
>>     
>>> [...]
>>> hi philippe, hope this helps:
>>>
>>>
>>> (gdb) bt
>>> #0  doublefault_fn () at arch/x86/kernel/doublefault_32.c:47
>>> #1  0x00000000 in ?? ()
>>>
>>> I set two breakpoints:
>>> 1) do_test_wp_bit()
>>> 2) zap_low_mappings()
>>>
>>> The second breakpoint is never reached, the fault seems to happen in
>>> do_test_wp_bit().
>>> arch/x86/mm/init_32.c : mem_init() -> test_wp_bit() -> do_test_wp_bit()
>>>   
>>>       
>> If I got it right, do_test_wp_bit() should fault, and then
>> ipipe_handle_exception gets called.
>> At this point, ipipe_init_early() was called, but ipipe_init() not.
>> So, I currently guess the bug is somewhere in ipipe_handle_exception().
>>     
> As mentioned below, you were right:
> http://git.denx.de/?p=ipipe-2.6.git;a=commit;h=d7ed9ab34a265d6486504d20ee794548ce6011d3
>
> Your assumption that the bootloader was involved in this bug was correct
> as well. This is the reason why I could not reproduce the issue over
> kvm, I was bypassing the installed bootloader, passing -kernel to qemu
> to directly load an external image, so no IRQ pending on entry to the
> kernel, ever...
>
> Thanks for your help.
>
>   

Tested with 2.6.32.20 and debian squeeze, boots fine, laptop and virtual
machine.
Thanks Philippe.

Stefan



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