Re: [Xenomai] universal application binary: how to auto-detect Xenomai/RT-PREEMPT/vanilla kernel

[Philippe Gerum <rpm@xenomai.org>]

On 01/14/2013 01:05 PM, Michael Haberler wrote:
> Gilles,
>
> Am 14.01.2013 um 12:57 schrieb Gilles Chanteperdrix:
>
>> On 01/14/2013 09:29 AM, Michael Haberler wrote:
>>
>>> Hi,
>>
>>
>> Hi,
>>
>>>
>>> thanks to patience on this list we were able to build linuxcnc such
>>> that it runs on Xenomai, besides RT-PREEMPT, vanilla kernels (in a
>>> simulator/non-RT mode) and RTAI
>>>
>>>
>>> I'm planning to adapt linuxcnc such that a universal binary can be
>>> built which runs under Xenomai, RT-PREEMPT and vanilla kernels as
>>> this will simplify logistics quite a bit; what I'd like have is
>>> reliable auto-detection of the kernel type and 'do the right thing'
>>> (RTAI will remain a separate build).
>>
>>
>> I have no idea about preempt_rt, however, in order to detect xenomai,
>> you can check for /dev/rtheap. If it does not exist, xenomai programs
>> will not start anyway. Also, I guess for a universal binary, you would
>> dlopen xenomai libraries (native or posix, depending on the one you want
>> to use), if you want to do that, you have to pass --enable-dlopen-skins
>> to xenomai configure script.
>
> thanks, that is a good idea to verify the libraries are in place; I had to use --enable-dlopen-skins anyway to make Python imports happy.
>
> I'll muddle my way through some string matching to find rt-preempt running; https://rt.wiki.kernel.org/index.php/RT_PREEMPT_HOWTO#Checking_the_Kernel gives some hints
>
> Is there any chance somebody runs Xenomai AND RT_PREEMPT patches applied? I heard a rumor but havent actually seen that

Yes, this works. The current target is ppc 85xx, but I don't see any 
showstopper for running such combo on other archs, provided the I-pipe 
patch is adapted to a -rt kernel. This requires Xenomai 2.6.1+, stock.

-- 
Philippe.