Soft Float for PC386

[Angelo Fraietta]

I am a full time student using RTEMS for a research project.  I will be delivering a paper at the Australasian Computer Music
Conference later this year, definitely boasting about the fantastic support that the RTEMS group has provided for free.  At my previous
employment, we switched to ATI Nucleus from MQX due to the support that they were to provide.  I found that the documentation and
support was nowhere near as good as what has been provided by the RTEMS group.  The time taken for replies has been no less than
fantastic. I still visit my previous employers and tell how good the RTEMS support is.
Apart from this, how else could I support RTEMS?

Joel Sherrill wrote:

> Ralf's explanation is 100% correct.  The RPMs have been building for
> a few days now.  There are now arm, h8300, i386, i960, and m68k
> binary RPMs built.  The mips, mips64orion, powerpc, sh, and sparc
> remain to be built.
>
> I will repeat my mantra -- RTEMS support, training, and development
> contracts pay for all RTEMS expenses.  I do not even work on RTEMS
> half-time!!!  My vision is that RTEMS development work is funneled
> others like Ralf and Eric Norum to support their ongoing
> efforts.  We all (including myself) do a lot of free RTEMS work.
> So if you are looking at using RTEMS in a real project, please
> consider supporting the world.  FYI Chris Johns is in your neck
> of the world and also quite capable of many tasks.
>
> Ralf Corsepius wrote:
> >
> > Angelo Fraietta wrote:
> > >
> > > If I build the pc386 with both the -mno-fp-ret-in-387 and the -msoft-float flags
> > > the machine re-boots if you try to create a task. Eg, if you try to run the
> > > ticker sample, the machine re-boots.  If you only use the -msoft-float and not
> > > the -mno-fp-ret-in-387 flag, the tasks run OK.
> > > I am mentioning this because the ts_386ex build uses both flags, and so if
> > > someone tests these on a ts_386ex, they may want to try running ticker on it to
> > > see if it crashes.
> > >
> > This doesn't surprize me, because newlib unconditionally inserts
> > FPU-code into its libc, no matter which compiler options are used
> > for building it. I.e. at least one cause of your problems is lurking
> > in newlib.
> >
> > I believe to have fixed this issue, so you could consider rebuilding
> > your gcc-newlib rpms, using the *.nosrc.rpm below, which contains my
> > fixes.
> >
> > Procedure for rebuilding:
> > 1) Copy gcc-2.95.2.tar.gz and newlib-1.9.0.tar.gz to
> > /usr/src/redhat/SOURCES.
> >
> > 2) rpm -i i386-rtems-gcc-newlib-gcc2.95.2newlib1.9.0-1.nosrc.rpm
> > [This will install RTEMS diffs and my patches to
> > /usr/src/redhat/SOURCES]
> >
> > 3)
> > export PATH=/opt/rtems/bin:$PATH
> > rpm -bb
> > /usr/src/redhat/SPECS/i386-rtems-gcc-newlib-gcc2.95.2newlib1.9.0.spec
> > [Now wait a couple of hours for the built to finish. Requires 500MB
> > to 1GB of free diskspace below /usr/src/redhat]
> >
> > 4) /usr/src/redhat/RPMS/i386 now should contain the new
> > i386-rtems-*.rpms
> >
> > 5) Rebuild RTEMS w/ -msoft-float -mno-fp-ret-in-387.
> >
> > 6) Test at run-time.
> >
> > Hope that helps.
> >
> > FYI: These patches already are submitted to Joel and to the newlib
> > maintainers.
> >
> > AFAIK, Joel already is preparing new RTEMS toolchain rpms. So if you
> > can't build the toolchain yourself for some reason, it's probably
> > only a matter of days until new RTEMS toolchain rpms will appear on
> > OAR's site.
> >
> > Ralf
> >
> > --
> > Ralf Corsepius
> > Forschungsinstitut fuer Anwendungsorientierte Wissensverarbeitung
> > (FAW)
> > Helmholtzstr. 16, 89081 Ulm, Germany     Tel: +49/731/501-8690
> > mailto:corsepiu at faw.uni-ulm.de           FAX: +49/731/501-999
> > http://www.faw.uni-ulm.de
> >
> >   ------------------------------------------------------------------------
> >                                                                     Name: i386-rtems-gcc-newlib-gcc2.95.2newlib1.9.0-1.nosrc.rpm
> >    i386-rtems-gcc-newlib-gcc2.95.2newlib1.9.0-1.nosrc.rpm           Type: RealPlayer(tm) as Plug-in (audio/x-pn-realaudio-plugin)
> >                                                                 Encoding: base64
> >                                                          Download Status: Not downloaded with message
>
> --
> Joel Sherrill, Ph.D.             Director of Research & Development
> joel at OARcorp.com                 On-Line Applications Research
> Ask me about RTEMS: a free RTOS  Huntsville AL 35805
>    Support Available             (256) 722-9985

--
Angelo Fraietta

PO Box 859
Hamilton NSW 2303

Home Page

http://users.hunterlink.net.au/~maaaf/

There are those who seek knowledge for the sake of knowledge - that is CURIOSITY
There are those who seek knowledge to be known by others - that is VANITY
There are those who seek knowledge in order to serve - that is LOVE
    Bernard of Clairvaux (1090 - 1153)