Re: [Xenomai-help] Xenomai Kernel Module & Watchdogs

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

Adrian Boeing wrote:
> Hi Gilles,
> 
> Thank you for your reply.
> 
> Not necessarily, the same priority scale is available in kernel-space
>> and user-space. However, are you aware that Xenomai already has a
>> watchdog? It is selectable in Linux configuration once linux sources
>> have been prepared.
> 
> 
> Yes, I saw it mentioned in an older version of the documentation, however I
> was unable to find the option. (The documentation mentions 'expert mode' in
> the 'general' menu - I was not able to find it.)

You need to enable xenomai debugging.

> 
> I would like to create a watchdog that watches my other real & non-realtime
> threads to make sure they are not starved/stuck/error etc. and reset them if
> necessary.
> 
> The documentation on 'alarm' mentions "Create an alarm object from kernel
> space". So I assumed they must be created in a kernel module.

No, as can be seen in the documentation, there are two rt_alarm_create
functions, one for user-space, one for kernel-space

> 
> 
>> 2. How do I create a kernel module? (what is the compiler command?)
>>
>> This question is off-topic on Xenomai mailing list, it is not related to
>> xenomai at all. But you have to get the module compiled by Linux kernel
>> makefiles. See Documentation/kbuild/modules.txt in the kernel sources.
> 
> 
> Thanks for the hints. One of the examples in the Xenomai documentation is
> "kernel_task.c"
> How should I compile and run this example? I assumed it was a kernel module.
> 
> This is how I compile it at the moment:
> gcc -I/usr/include/xenomai -D_GNU_SOURCE -D_REENTRANT -D__XENO__
> -L/usr/lib -lpthread  -lnative -Xlinker -rpath -Xlinker /usr/lib  -c kmod.c
> 
> Try to run it:
> sudo insmod ./kmod.o
> 
> I get this error:
> insmod: error inserting './kmod.o': -1 Invalid module format

I repeat myself: "you have to get the module compiled by Linux kernel
makefiles. See Documentation/kbuild/modules.txt in the kernel sources."

Please do not drop the mailing list from the CC.

-- 
                                                 Gilles.