Re: [Xenomai-help] Commercial use of Xenomai

[Philippe Gerum <rpm@xenomai.org>]

Rosenow, Jim wrote:
> First let me start by saying I apologize if xenomai-help is the wrong 
> list, I found a xenomai-main which I though more likely the correct list 
> but it has had no activity.
>

Xenomai-main is a hidden and dead list. Active lists are listed here:
http://gna.org/mail/?group=xenomai

>  
> 
> I had been following fusion for some time with an eye toward the 
> possibility of commercial use due to it being user-space real-time and 
> thus more likely to allow protection of intellectual property.  I’m 
> pleased to see a continuation of fusion in the Xenomai project.
> 
>  
> 
>  
> 
> I’ve searched the archives for license details and have only found 
> reference to GPL V2.
> 

Look harder: e.g. skins/native/lib/COPYING (v2.0.x) or 
src/skins/native/COPYING (v2.1). LGPL inside.

>  
> 
> My primary question is if a user space Xenomai real-time application is 
> considered a derivate work and thus is subject to be GPL’d?
> 
>  

1. Xenomai libraries that provide system call wrappers to invoke the 
real-time nucleus services from user-space are LGPL. E.g. libnative.so 
and libpthread_rt.so. Application-wise, those have the same role with 
respect to the Xenomai nucleus than the glibc has with respect to the 
Linux kernel. This is likely what you want to use.

2. Xenomai libraries that provide the UVM support are licensed under the 
GPL, with a specific exception clause that basically says that mere 
linking against such unmodified libraries does not cause by itself the 
application to be covered by the GPL. Rationale: UVM support is mainly 
composed of GPLed kernel-based code (nucleus, various RTOS skins), but 
compiled for a different execution environment, so that the UVM can run 
it over a virtual machine layer, all of this being in the context of a 
regular Linux process in user-space. For this reason, the base license 
remains the GPL, but the exception is there for what is worth.

3. All Xenomai code running in Linux kernel space is GPL.

4. All Xenomai code implementing the simulator (i.e. sim/ directory) is GPL.

-- 

Philippe.