Okay /Jesper
On 2011-04-19 11:30, Philippe Gerum wrote: > 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. > > _______________________________________________ Xenomai-core mailing list Xenomai-core@gna.org https://mail.gna.org/listinfo/xenomai-core
