Re: [Xenomai-main] Xenomai only for x86-architecture

[Niklaus Giger]

On Freitag, 11. Oktober 2002 18.43, Philippe Gerum wrote:
> This small layer currently exists for x86 only (see
> nucleus/arch/rtai-x86.h or nucleus/arch/adeos-x86.h) if you plan to
> have your application run as a kernel module in order to achieve hard
> real-time. OTOH, if soft RT is ok for your needs, you should be able
> to run Xenomai (including its emulators) in user space over its posix
> (see nucleus/arch/posix.h) layer on a PPC box, but AFAIK, this has not
> been done yet.
Unfortunately this is not possible as on the PPC-architecture the 
atomic-operations are not implemented on the user side, only inside the 
kernel. (e.g. compare asm-i386/atomic.h with asm-ppc/atomic.h).
> Porting the kernel-based layers to PPC should be quite simple for
> anyone who knows enough about the PPC interrupt subsystem. In the
> specific case of rtai for PPC, this port is even already available
> from the RTAI project (www.rtai.org), so what's needed for Xenomai is
> only adding a few PPC bits on top of it such as Xenomai-specific FPU
> support routines.
In fact I know the interrupt controller of at least one incaration hw quite 
(We have a PPC403 custom board) quite well as I adapted the vxWorks interrupt 
driver to support a different priority scheme.
>
> Some useful pointers:
> http://www.nongnu.org/xenomai/perspective.html
> http://www.nongnu.org/xenomai/layers.html
Thanks a lot. I think the port is feasible, but first I have to convince 
management to switch to GNU/Linux with RTAI. Or I will just do it for fun, 
but after my vacations which just started.

Best regards

-- 
Niklaus Giger
Wieshoschet 6
CH-8753 Mollis
Tel. ++41 55 612 20 54 (privat)
Tel. ++41 55 618 64 68 (Geschäft)