On Tue, 2011-04-19 at 11:29 +0200, Philippe Gerum wrote: > On Tue, 2011-04-19 at 10:42 +0200, Gilles Chanteperdrix wrote: > > Philippe Gerum wrote: > > > On Tue, 2011-04-19 at 09:58 +0200, Jesper Christensen wrote: > > >> Great thanks, but i can't help wondering if the problems i'm seeing are > > >> related to some of my userspace programs using fp. > > > > > > I don't think so. The switchtest programs exercises the FPU hardware in > > > a certain way to make sure it is available in real-time mode from kernel > > > space (which is an utterly crappy legacy, but we will have to deal with > > > it until Xenomai 3.x). As far as I can see from your .config, you can't > > > have such support, so switchtest was basically trying to test an > > > inexistent feature. > > > > In fact, switchtest whether Xenomai FPU switch routines work when the > > Linux kernel itself uses FPU in kernel-space. Currently, the only place > > when this happens is in the RAID code: x86 uses mmx/sse, and some power > > pcs use altivec. Some powerpc also fix unaligned accesses to floating > > point data in kernel-space, I do not know if this may interfere, which > > is why the powerpc code is compiled even without RAID. > > > > > > AFAICS, fp_regs_set() on ppc is issuing a load float instruction in > kernel space which could be unaligned, and therefore trap. Looking at > the .config for the target system, hw FPU support is disabled in the > alignment code, so basically, this would beget a nop.
A nop in fixing the issue, I mean. -- Philippe. _______________________________________________ Xenomai-core mailing list [email protected] https://mail.gna.org/listinfo/xenomai-core
