MVME3100 FPU Support on RTEMS 4.10.2

[Gedare Bloom]

On Wed, Jun 6, 2018 at 10:35 PM, Heinz Junkes <junkes at fhi-berlin.mpg.de> wrote:
> There is RTEMS 5 support for the MVME2500 made by Sebastian Huber.
> Unfortunately, I have not been able to test it properly with EPICS7.
> I will try it after the Epics meeting and will report.
>

The BSP support for mvme2500 is in the qoriq family of powerpc BSPs. I
have no clue how difficult it would be to use with 4.10. The APU route
suggested by Till is probably ideal unless you need 'double' types...

Gedare

> Heinz
>
>> On 6. Jun 2018, at 23:24, Matt Rippa <mrippa at gemini.edu> wrote:
>>
>> Thanks for the fast reply. Of all the mvme boards you listed,
>> the 3100 hits a nice price point and we're attempting to find
>> suitable replacement stock (quantity 30+) for the 2700 which are no longer
>> manufactured.
>>
>> Are the 6100 boards on beatnik bsp the only remaining option for RTEMS?
>> They cost nearly twice as much and have shown thermal regulation issues.
>>
>> -Matt
>>
>> On Wed, Jun 6, 2018 at 11:10 AM, Michael Davidsaver <mdavidsaver at ospreydcs.com> wrote:
>> Hi Matt,
>>
>> The MVME3100 is based on the MPC8540 processor.  This chip doesn't have an FPU.
>> Other boards do (eg. mvme270x, mvme6100, or mvme2500) and RTEMS supports this.
>>
>> I can certainly confirm that lack of an FPU really hurts performance, even
>> something as (apparently) simple as integer to float.
>>
>> Michael
>>
>>
>> On 06/06/2018 02:03 PM, Matt Rippa wrote:
>> > It appears we've compiled our mvme3100 bsp without FPU support.
>> > We're on the mvme3100 running EPICS 3.14.12.7 and RTEMS 4.10.2.
>> >
>> > We're attempting to commission our astrometric kernel control system
>> > and we've run into trouble meeting some of our thread deadlines. What
>> > we've found is a transform routine that takes our mvme2700 ~200 us,
>> > takes the mvme3100 ~8 ms.  So not a surprise to see this with only "-msoft-float"?
>> >
>> > ...
>> > 2018-05-31-tcs.log:May 31 11:41:15  E) PORT: tcs_vme, MSG: Welcome to rtems-4.10.2(PowerPC/Generic (*no FPU*)/mvme3100)
>> >
>> > Is FPU support possible with RTEMS 4.10.2? If so, what would we need to do?
>> > It looks like there's a multilib on 4.11.2 https://docs.rtems.org/releases/rtems-docs-4.11.2/cpu-supplement/powerpc.html#multilibs(*Eg., see #13* )
>> >
>> > Here's our bsp specs:
>> >
>> > beatnik:
>> > -specs bsp_specs -qrtems -fasm -c -mcpu=7400 -D__ppc_generic -DUNIX -O2 -g -g -Wall
>> > (mvme2700) mvme-2307:
>> > -specs bsp_specs -qrtems -fasm -c -mcpu=604 -mmultiple -mstring -mstrict-align -meabi -DUNIX -O2 -g -g -Wall
>> > mvme-3100
>> > -specs bsp_specs -qrtems -fasm -c -mcpu=powerpc *-msoft-float* -D__ppc_generic -DUNIX -O2 -g -g -Wall
>> >
>> > Thank you!
>> > -Matt
>> >
>>
>>
>>
>> --
>>
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>
>
> ----------------------------------------------------------------------
> Das FHI verarbeitet, speichert und loescht Daten im Rahmen seiner
> Geschaeftstaetigkeit gemaess der Datenschutz-Grundverordnung (DSGVO)
> [General Data Protection Regulation (GDPR)] der Europaeischen Union.
>
>
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