Re: [Xenomai-help] fpu issue

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

Steven Seeger wrote:
>> __xnpod_init_fpu is for kernel-space thread. For user-space threads,
>> the
>> FPU initialization happens either in Linux code if the fault happens
> in
>> secondary mode, or in the fault handler if it happens in primary mode.
> 
> Interesting. Shouldn't rt_task_spawn() start up in primary mode even if
> it's called in user space? Is it normal to start in secondary mode? I
> know std::cout will migrate to secondary, but I do my fpu stuff before
> that.

When you first use fpu in primary mode, a fault happen, is trapped in
ksrc/nucleus/pod.c and directly calls xnarch_init_fpu, not
__xnpod_init_fpu. Now, the fact that xnarch_init_fpu is not called may
indeed be your problem, but we have to know exactly what happens before
to understand why this happens.

-- 
                                                 Gilles.