[Buildroot] Sparc Leon support in Buildroot

[Buildroot] Sparc Leon support in Buildroot

[Thomas Petazzoni]

Hello Konrad,

Back in 2010, you contributed a number of patches to Buildroot to
support the Sparc Leon processors. It turns out that today, those
processors are the only one still needing gcc 4.4.x:

        prompt "GCC compiler Version"
        default BR2_GCC_VERSION_4_4_X if BR2_sparc_sparchfleon || BR2_sparc_sparchfleonv8 || BR2_sparc_sparcsfleon || BR2_sparc_sparcsfleonv8
        default BR2_GCC_VERSION_4_2_2_AVR32_2_1_5 if BR2_avr32
        default BR2_GCC_VERSION_4_7_X if BR2_sparc
        default BR2_GCC_VERSION_4_8_ARC if BR2_arc
        default BR2_GCC_VERSION_4_9_X if BR2_microblaze || BR2_powerpc64le
        default BR2_GCC_VERSION_4_5_X if BR2_bfin
        default BR2_GCC_VERSION_4_8_X

Do you know if there's any reason to still keep gcc 4.4 for those
processors? Wasn't the support for Sparc Leon merged in upstream gcc?
From https://sourceware.org/ml/crossgcc/2011-12/msg00004.html, I see
that some patches were still needed for gcc 4.6, but according to
https://gcc.gnu.org/onlinedocs/gcc/SPARC-Options.html, Sparc Leon
processors seem to be supported.

According to https://gcc.gnu.org/gcc-4.6/changes.html, the Sparc Leon
supported was merged in gcc 4.6: "GCC now supports the LEON series of
SPARC V8 processors. The code generated by the compiler can either be
tuned to it by means of the --with-tune=leon configure option and
-mtune=leon compilation option, or the compiler can be built for the
sparc-leon-{elf,linux} and sparc-leon3-{elf,linux} targets directly.".

Could you update us on the Sparc Leon support, and maybe submit some
patches to Buildroot to make the relevant changes?

Thanks!

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[Buildroot] Sparc Leon support in Buildroot

[Andreas Larsson]

On 2014-07-01 20:22, Thomas Petazzoni wrote:
> Hello Konrad,
>
> Back in 2010, you contributed a number of patches to Buildroot to
> support the Sparc Leon processors. It turns out that today, those
> processors are the only one still needing gcc 4.4.x:
>
>          prompt "GCC compiler Version"
>          default BR2_GCC_VERSION_4_4_X if BR2_sparc_sparchfleon || BR2_sparc_sparchfleonv8 || BR2_sparc_sparcsfleon || BR2_sparc_sparcsfleonv8
>          default BR2_GCC_VERSION_4_2_2_AVR32_2_1_5 if BR2_avr32
>          default BR2_GCC_VERSION_4_7_X if BR2_sparc
>          default BR2_GCC_VERSION_4_8_ARC if BR2_arc
>          default BR2_GCC_VERSION_4_9_X if BR2_microblaze || BR2_powerpc64le
>          default BR2_GCC_VERSION_4_5_X if BR2_bfin
>          default BR2_GCC_VERSION_4_8_X
>
> Do you know if there's any reason to still keep gcc 4.4 for those
> processors? Wasn't the support for Sparc Leon merged in upstream gcc?
>  From https://sourceware.org/ml/crossgcc/2011-12/msg00004.html, I see
> that some patches were still needed for gcc 4.6, but according to
> https://gcc.gnu.org/onlinedocs/gcc/SPARC-Options.html, Sparc Leon
> processors seem to be supported.
>
> According to https://gcc.gnu.org/gcc-4.6/changes.html, the Sparc Leon
> supported was merged in gcc 4.6: "GCC now supports the LEON series of
> SPARC V8 processors. The code generated by the compiler can either be
> tuned to it by means of the --with-tune=leon configure option and
> -mtune=leon compilation option, or the compiler can be built for the
> sparc-leon-{elf,linux} and sparc-leon3-{elf,linux} targets directly.".
>
> Could you update us on the Sparc Leon support, and maybe submit some
> patches to Buildroot to make the relevant changes?


Hi!

I am looking into this and will submit some patches.

Best regards,

Andreas Larsson
Software Engineer
Aeroflex Gaisler AB
Aeroflex Microelectronic Solutions ? HiRel
Kungsgatan 12
SE-411 19 Gothenburg, Sweden
Phone: +46 31 7758669
andreas at gaisler.com
www.Aeroflex.com/Gaisler

[Buildroot] Sparc Leon support in Buildroot

[Thomas Petazzoni]

Dear Andreas Larsson,

On Wed, 20 Aug 2014 13:01:33 +0200, Andreas Larsson wrote:

> > Do you know if there's any reason to still keep gcc 4.4 for those
> > processors? Wasn't the support for Sparc Leon merged in upstream gcc?
> >  From https://sourceware.org/ml/crossgcc/2011-12/msg00004.html, I see
> > that some patches were still needed for gcc 4.6, but according to
> > https://gcc.gnu.org/onlinedocs/gcc/SPARC-Options.html, Sparc Leon
> > processors seem to be supported.
> >
> > According to https://gcc.gnu.org/gcc-4.6/changes.html, the Sparc Leon
> > supported was merged in gcc 4.6: "GCC now supports the LEON series of
> > SPARC V8 processors. The code generated by the compiler can either be
> > tuned to it by means of the --with-tune=leon configure option and
> > -mtune=leon compilation option, or the compiler can be built for the
> > sparc-leon-{elf,linux} and sparc-leon3-{elf,linux} targets directly.".
> >
> > Could you update us on the Sparc Leon support, and maybe submit some
> > patches to Buildroot to make the relevant changes?
> 
> 
> Hi!
> 
> I am looking into this and will submit some patches.

Great, thanks! Also, currently, we don't have any Sparc toolchain in
our autobuilder testing. Normally, we try to have all architectures we
support tested in our autobuilders. If we were to add the Sparc
architecture to our testing infrastructure, would you be willing to
look at the potential build failures that may result from this testing?
(Look at http://autobuild.buildroot.org to see what the results look
like for other architectures).

Thanks!

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[Buildroot] Sparc Leon support in Buildroot

[Andreas Larsson]

On 2014-08-20 14:05, Thomas Petazzoni wrote:
> Dear Andreas Larsson,
>
> On Wed, 20 Aug 2014 13:01:33 +0200, Andreas Larsson wrote:
>
>>> Do you know if there's any reason to still keep gcc 4.4 for those
>>> processors? Wasn't the support for Sparc Leon merged in upstream gcc?
>>>   From https://sourceware.org/ml/crossgcc/2011-12/msg00004.html, I see
>>> that some patches were still needed for gcc 4.6, but according to
>>> https://gcc.gnu.org/onlinedocs/gcc/SPARC-Options.html, Sparc Leon
>>> processors seem to be supported.
>>>
>>> According to https://gcc.gnu.org/gcc-4.6/changes.html, the Sparc Leon
>>> supported was merged in gcc 4.6: "GCC now supports the LEON series of
>>> SPARC V8 processors. The code generated by the compiler can either be
>>> tuned to it by means of the --with-tune=leon configure option and
>>> -mtune=leon compilation option, or the compiler can be built for the
>>> sparc-leon-{elf,linux} and sparc-leon3-{elf,linux} targets directly.".
>>>
>>> Could you update us on the Sparc Leon support, and maybe submit some
>>> patches to Buildroot to make the relevant changes?
>>
>>
>> Hi!
>>
>> I am looking into this and will submit some patches.
>
> Great, thanks! Also, currently, we don't have any Sparc toolchain in
> our autobuilder testing. Normally, we try to have all architectures we
> support tested in our autobuilders. If we were to add the Sparc
> architecture to our testing infrastructure, would you be willing to
> look at the potential build failures that may result from this testing?
> (Look at http://autobuild.buildroot.org to see what the results look
> like for other architectures).

If that would be set up, it is something I could keep an eye on. 
However, I do not have the possibility to take responsibility for broken 
packages.

Best regards,
Andreas Larsson

[Buildroot] Sparc Leon support in Buildroot

[Thomas Petazzoni]

Dear Andreas Larsson,

On Wed, 03 Sep 2014 16:13:24 +0200, Andreas Larsson wrote:

> > Great, thanks! Also, currently, we don't have any Sparc toolchain in
> > our autobuilder testing. Normally, we try to have all architectures we
> > support tested in our autobuilders. If we were to add the Sparc
> > architecture to our testing infrastructure, would you be willing to
> > look at the potential build failures that may result from this testing?
> > (Look at http://autobuild.buildroot.org to see what the results look
> > like for other architectures).
> 
> If that would be set up, it is something I could keep an eye on. 
> However, I do not have the possibility to take responsibility for broken 
> packages.

Well, it's not really a "responsibility": most of the Buildroot
contributors are volunteers so there are no obligations. But if you can
give some help from time to time for some SPARC specific issues, that
would be nice.

Have you had some time to look at the toolchain components? As I said
earlier, we are currently keeping gcc 4.4.x only for SPARC Leon, so if
you could test if gcc 4.8.x and/or 4.9.x work fine for Leon, it would
allow us to get rid of the support for gcc 4.4.

See package/gcc/Config.in.host for the details of the gcc versions that
we allow for SPARC Leon.

Thanks a lot!

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[Buildroot] Sparc Leon support in Buildroot

[Andreas Larsson]

On 2014-09-03 16:45, Thomas Petazzoni wrote:
> Dear Andreas Larsson,
>
> On Wed, 03 Sep 2014 16:13:24 +0200, Andreas Larsson wrote:
>
>>> Great, thanks! Also, currently, we don't have any Sparc toolchain in
>>> our autobuilder testing. Normally, we try to have all architectures we
>>> support tested in our autobuilders. If we were to add the Sparc
>>> architecture to our testing infrastructure, would you be willing to
>>> look at the potential build failures that may result from this testing?
>>> (Look at http://autobuild.buildroot.org to see what the results look
>>> like for other architectures).
>>
>> If that would be set up, it is something I could keep an eye on.
>> However, I do not have the possibility to take responsibility for broken
>> packages.
>
> Well, it's not really a "responsibility": most of the Buildroot
> contributors are volunteers so there are no obligations. But if you can
> give some help from time to time for some SPARC specific issues, that
> would be nice.
>
> Have you had some time to look at the toolchain components? As I said
> earlier, we are currently keeping gcc 4.4.x only for SPARC Leon, so if
> you could test if gcc 4.8.x and/or 4.9.x work fine for Leon, it would
> allow us to get rid of the support for gcc 4.4.

gcc 4.8.x and 4.9.x produces a bug that seems to be due to memset 
optimizations and a surprising memset behavior in sparc Linux. I have 
submitted a kernel patch to fix this 
(https://lkml.org/lkml/2014/8/29/333). This (or some other fix to the 
problem) should go into mainline and stable branches before claiming gcc 
4.8/4.9 working for leon in my opinion. I'll have to test more if there 
are other problems with the newer gcc:s as well.

Cheers,
Andreas