[ptxdist] ptxdist with iMX6

[ptxdist] ptxdist with iMX6

[Guillermo Rodriguez Garcia]

Hi all,

Is someone using ptxdist with iMX6 based targets? I know phytec used
ptxdist in the past but now they seem to be using Yocto instead.

Re. toolchain: Any recommended version of OSELAS.Toolchain? Best
settings to finetune for Cortex A9 + VFPv3 + NEON ?

Thank you,

Guillermo Rodriguez Garcia
guille.rodriguez@gmail.com

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Re: [ptxdist] ptxdist with iMX6

[Alexander Dahl]

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Hei hei,

On Wed, Mar 01, 2017 at 06:36:38PM +0100, Guillermo Rodriguez Garcia wrote:
> Is someone using ptxdist with iMX6 based targets? I know phytec used
> ptxdist in the past but now they seem to be using Yocto instead.

We have a phytec i.MX6 dev board at work. They shipped a ptxdist based
BSP in the first place before they switched to ptxdist. I had
Distrokit working with it, I guess when Linux 3.18 was bleeding edge,
but did not manage to send it upstream.

So in general i.MX6 works, I guess it's basically getting your
bootloader and kernel config working?

> Re. toolchain: Any recommended version of OSELAS.Toolchain? Best
> settings to finetune for Cortex A9 + VFPv3 + NEON ?

I would recommend the latest release v2016.06.1 and go with
arm-v7a-linux-gnueabihf_gcc-5.4.0_glibc-2.23_binutils-2.26_kernel-4.6-sanitized.ptxconfig

Greets
Alex

-- 
»With the first link, the chain is forged. The first speech censured, 
the first thought forbidden, the first freedom denied, chains us all 
irrevocably.« (Jean-Luc Picard, quoting Judge Aaron Satie)
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Re: [ptxdist] ptxdist with iMX6

[Guillermo Rodriguez Garcia]

Hi Alexander,

Thank you for your answer.

2017-03-01 22:03 GMT+01:00 Alexander Dahl <post@lespocky.de>:
> Hei hei,
>
> On Wed, Mar 01, 2017 at 06:36:38PM +0100, Guillermo Rodriguez Garcia wrote:
>> Is someone using ptxdist with iMX6 based targets? I know phytec used
>> ptxdist in the past but now they seem to be using Yocto instead.
>
> We have a phytec i.MX6 dev board at work. They shipped a ptxdist based
> BSP in the first place before they switched to ptxdist. I had
> Distrokit working with it, I guess when Linux 3.18 was bleeding edge,
> but did not manage to send it upstream.
>
> So in general i.MX6 works, I guess it's basically getting your
> bootloader and kernel config working?

Yes, indeed. Selecting the right kernel to start from is already a
non-trivial task, given the plethora of options (we have at least:
official Freescale/NXP kernels, community kernels, vendor kernels from
board/SOM manufacturers, and the upstream kernel).

>
>> Re. toolchain: Any recommended version of OSELAS.Toolchain? Best
>> settings to finetune for Cortex A9 + VFPv3 + NEON ?
>
> I would recommend the latest release v2016.06.1 and go with
> arm-v7a-linux-gnueabihf_gcc-5.4.0_glibc-2.23_binutils-2.26_kernel-4.6-sanitized.ptxconfig

That is a great start. Some things that draw my attention, though:

- VFPv3-D16 selected whereas iMX6 can do VFPv3-D32 (or just "VFPv3")
- NEON not enabled (supported by iMX6)
- Thumb mode used by default (not sure why -- wouldn't it be more
appropriate to use arm mode by default unless there is an explicit
intent to optimize size over speed ?)

Best,

Guillermo

guille.rodriguez@gmail.com

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Re: [ptxdist] ptxdist with iMX6

[Clemens Gruber]

Hi Guillermo,

On Thu, Mar 02, 2017 at 03:50:19PM +0100, Guillermo Rodriguez Garcia wrote:
> Hi Alexander,
> 
> Thank you for your answer.
> 
> 2017-03-01 22:03 GMT+01:00 Alexander Dahl <post@lespocky.de>:
> > Hei hei,
> >
> > On Wed, Mar 01, 2017 at 06:36:38PM +0100, Guillermo Rodriguez Garcia wrote:
> >> Is someone using ptxdist with iMX6 based targets? I know phytec used
> >> ptxdist in the past but now they seem to be using Yocto instead.

We use PTXdist for an i.MX6Q based target. The toolchain we use is based
on OSELAS.Toolchain, but I updated it to use the most recent GCC 6.3.0,
glibc 2.25, binutils 2.27, gdb 7.12.1, kernel-headers, etc.
Also changed some configure options to enable a few additional features
and improve the reproducability of builds. Besides that, I also added a
few patches from the buildroot project.
Not sure if it is upstreamable because I can't test if the other
ptxconfigs still work and I only ever used it for our i.MX6Q board.

But if you are interested I could send a few patches or create a GitHub
repo to work on it.

> That is a great start. Some things that draw my attention, though:
> 
> - VFPv3-D16 selected whereas iMX6 can do VFPv3-D32 (or just "VFPv3")

For the i.MX6 you can use the full VFPv3-D32 but I'd recommend using
-mfpu=neon instead. Performance is a little bit better than with
-mfpu=vfpv3.

> - Thumb mode used by default (not sure why -- wouldn't it be more
> appropriate to use arm mode by default unless there is an explicit
> intent to optimize size over speed ?)

Yes, the performance is better than with Thumb 2. (Maybe related to the
conditional execution feature in the original ARM instruction set..
still being faster than the use of the IT instruction in Thumb-2?)

Space and memory are not the biggest concerns on our board (4GB eMMC,
1GB RAM), so using ARM mode made sense and works great.

Regards,
Clemens

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[ptxdist] GitHub and free software

[Uwe Kleine-König]

Hello,

On Thu, Mar 02, 2017 at 05:17:41PM +0100, Clemens Gruber wrote:
> But if you are interested I could send a few patches or create a GitHub
> repo to work on it.
INAL etc pp. I didn't even read the updated GitHub TOS, but you might
want to read through

	https://www.mirbsd.org/permalinks/wlog-10_e20170301-tg.htm

and then judge for yourself if you can and want to still push stuff there.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

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Re: [ptxdist] GitHub and free software

[Guillermo Rodriguez Garcia]

IANAL either but just to balance.
There are also people out there saying that this analysis is not
correct (some of which claim to be lawyers).


2017-03-02 18:35 GMT+01:00 Uwe Kleine-König <u.kleine-koenig@pengutronix.de>:
> Hello,
>
> On Thu, Mar 02, 2017 at 05:17:41PM +0100, Clemens Gruber wrote:
>> But if you are interested I could send a few patches or create a GitHub
>> repo to work on it.
> INAL etc pp. I didn't even read the updated GitHub TOS, but you might
> want to read through
>
>         https://www.mirbsd.org/permalinks/wlog-10_e20170301-tg.htm
>
> and then judge for yourself if you can and want to still push stuff there.
>
> Best regards
> Uwe
>
> --
> Pengutronix e.K.                           | Uwe Kleine-König            |
> Industrial Linux Solutions                 | http://www.pengutronix.de/  |
>
> _______________________________________________
> ptxdist mailing list
> ptxdist@pengutronix.de



-- 
Guillermo Rodriguez Garcia
guille.rodriguez@gmail.com

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Re: [ptxdist] GitHub and free software

[Guillermo Rodriguez Garcia]

(sorry, previous message was sent accidentally)

IANAL either but just to balance.
There are also people out there saying that this analysis is not
correct (some of which claim to be lawyers).

Here's a thread on Ycombinator discussing this topic.

https://news.ycombinator.com/item?id=13766933

Guillermo

2017-03-02 19:17 GMT+01:00 Guillermo Rodriguez Garcia
<guille.rodriguez@gmail.com>:
> IANAL either but just to balance.
> There are also people out there saying that this analysis is not
> correct (some of which claim to be lawyers).
>
>
> 2017-03-02 18:35 GMT+01:00 Uwe Kleine-König <u.kleine-koenig@pengutronix.de>:
>> Hello,
>>
>> On Thu, Mar 02, 2017 at 05:17:41PM +0100, Clemens Gruber wrote:
>>> But if you are interested I could send a few patches or create a GitHub
>>> repo to work on it.
>> INAL etc pp. I didn't even read the updated GitHub TOS, but you might
>> want to read through
>>
>>         https://www.mirbsd.org/permalinks/wlog-10_e20170301-tg.htm
>>
>> and then judge for yourself if you can and want to still push stuff there.
>>
>> Best regards
>> Uwe
>>
>> --
>> Pengutronix e.K.                           | Uwe Kleine-König            |
>> Industrial Linux Solutions                 | http://www.pengutronix.de/  |
>>
>> _______________________________________________
>> ptxdist mailing list
>> ptxdist@pengutronix.de
>
>
>
> --
> Guillermo Rodriguez Garcia
> guille.rodriguez@gmail.com



-- 
Guillermo Rodriguez Garcia
guille.rodriguez@gmail.com

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Re: [ptxdist] GitHub and free software

[Clemens Gruber]

Hi,

On Thu, Mar 02, 2017 at 06:35:42PM +0100, Uwe Kleine-König wrote:
> Hello,
> 
> On Thu, Mar 02, 2017 at 05:17:41PM +0100, Clemens Gruber wrote:
> > But if you are interested I could send a few patches or create a GitHub
> > repo to work on it.
> INAL etc pp. I didn't even read the updated GitHub TOS, but you might
> want to read through
> 
> 	https://www.mirbsd.org/permalinks/wlog-10_e20170301-tg.htm
> 
> and then judge for yourself if you can and want to still push stuff there.

Thanks for sharing this blog post. The new ToS do indeed sound
problematic.

Hopefully the FSF will soon release a statement about this and clarify
for us non-lawyers if this is problematic for code under copyleft
licenses and if they recommend against using GitHub for free software
projects from now on.

Regards,
Clemens

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Re: [ptxdist] GitHub and free software

[Clemens Gruber]

On Thu, Mar 02, 2017 at 06:35:42PM +0100, Uwe Kleine-König wrote:
> Hello,
> 
> On Thu, Mar 02, 2017 at 05:17:41PM +0100, Clemens Gruber wrote:
> > But if you are interested I could send a few patches or create a GitHub
> > repo to work on it.
> INAL etc pp. I didn't even read the updated GitHub TOS, but you might
> want to read through
> 
> 	https://www.mirbsd.org/permalinks/wlog-10_e20170301-tg.htm
> 
> and then judge for yourself if you can and want to still push stuff there.
> 
> Best regards
> Uwe

https://www.fsf.org/blogs/licensing/do-githubs-updated-terms-of-service-conflict-with-copyleft

Regards,
Clemens

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Re: [ptxdist] GitHub and free software

[Roland Hieber]

On 16.03.2017 16:53, Clemens Gruber wrote:
> On Thu, Mar 02, 2017 at 06:35:42PM +0100, Uwe Kleine-König wrote:
>> […]
>> 	https://www.mirbsd.org/permalinks/wlog-10_e20170301-tg.htm
>> […]
> 
> https://www.fsf.org/blogs/licensing/do-githubs-updated-terms-of-service-conflict-with-copyleft

Also see LWNs analysis of the situation:

https://lwn.net/Articles/716372/

 - Roland

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Re: [ptxdist] GitHub and free software

[Robert Schwebel]

On Fri, Mar 17, 2017 at 09:50:57PM +0100, Roland Hieber wrote:
> On 16.03.2017 16:53, Clemens Gruber wrote:
> > On Thu, Mar 02, 2017 at 06:35:42PM +0100, Uwe Kleine-König wrote:
> >> […]
> >> 	https://www.mirbsd.org/permalinks/wlog-10_e20170301-tg.htm
> >> […]
> > 
> > https://www.fsf.org/blogs/licensing/do-githubs-updated-terms-of-service-conflict-with-copyleft
> 
> Also see LWNs analysis of the situation:
> 
> https://lwn.net/Articles/716372/

The FSF statement basically backs what we have analyzed during the last
weeks.

Robert
-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
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Re: [ptxdist] ptxdist with iMX6

[Alexander Dahl]

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Hei hei,

On Thu, Mar 02, 2017 at 03:50:19PM +0100, Guillermo Rodriguez Garcia wrote:
> Yes, indeed. Selecting the right kernel to start from is already a
> non-trivial task, given the plethora of options (we have at least:
> official Freescale/NXP kernels, community kernels, vendor kernels from
> board/SOM manufacturers, and the upstream kernel).

I would go with a recent vanilla kernel first. i.MX6 support is quite
mature these days. Maybe you have to write your own DTS file or adapt
another, but this should at least bring you to a running board with
serial console. That's a good start.

> > I would recommend the latest release v2016.06.1 and go with
> > arm-v7a-linux-gnueabihf_gcc-5.4.0_glibc-2.23_binutils-2.26_kernel-4.6-sanitized.ptxconfig
> 
> That is a great start. Some things that draw my attention, though:

Sorry, I'm not familiar with toolchain details. As far as I can tell
ptxdist uses more or less generic toolchains which should work for a
wider range of boards. If you want to squeeze the last bit of
performance you may want to configure and build your own toolchain or
have a look at another project, but just using the above should
certainly be enough if you don't have very tight performance
requirements.

Greets
Alex

-- 
»With the first link, the chain is forged. The first speech censured, 
the first thought forbidden, the first freedom denied, chains us all 
irrevocably.« (Jean-Luc Picard, quoting Judge Aaron Satie)
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Re: [ptxdist] ptxdist with iMX6

[Michael Olbrich]

Hi,

On Thu, Mar 02, 2017 at 03:50:19PM +0100, Guillermo Rodriguez Garcia wrote:
> 2017-03-01 22:03 GMT+01:00 Alexander Dahl <post@lespocky.de>:
> > Hei hei,
> >
> > On Wed, Mar 01, 2017 at 06:36:38PM +0100, Guillermo Rodriguez Garcia wrote:
> >> Is someone using ptxdist with iMX6 based targets? I know phytec used
> >> ptxdist in the past but now they seem to be using Yocto instead.
> >
> > We have a phytec i.MX6 dev board at work. They shipped a ptxdist based
> > BSP in the first place before they switched to ptxdist. I had
> > Distrokit working with it, I guess when Linux 3.18 was bleeding edge,
> > but did not manage to send it upstream.
> >
> > So in general i.MX6 works, I guess it's basically getting your
> > bootloader and kernel config working?
> 
> Yes, indeed. Selecting the right kernel to start from is already a
> non-trivial task, given the plethora of options (we have at least:
> official Freescale/NXP kernels, community kernels, vendor kernels from
> board/SOM manufacturers, and the upstream kernel).
> 
> >
> >> Re. toolchain: Any recommended version of OSELAS.Toolchain? Best
> >> settings to finetune for Cortex A9 + VFPv3 + NEON ?
> >
> > I would recommend the latest release v2016.06.1 and go with
> > arm-v7a-linux-gnueabihf_gcc-5.4.0_glibc-2.23_binutils-2.26_kernel-4.6-sanitized.ptxconfig
> 
> That is a great start. Some things that draw my attention, though:
> 
> - VFPv3-D16 selected whereas iMX6 can do VFPv3-D32 (or just "VFPv3")
> - NEON not enabled (supported by iMX6)

For the glibc this makes no real difference. It has neon optimizes memcpy
etc. that is selected at runtime. Maybe some math functions are slower, but
I've not heard of any issues there. For the BSP just set TARGET_EXTRA_CFLAGS
/ TARGET_EXTRA_CXXFLAGS to add the appropriate -mcpu/-mfpu.

> - Thumb mode used by default (not sure why -- wouldn't it be more
> appropriate to use arm mode by default unless there is an explicit
> intent to optimize size over speed ?)

For ARMv7 thumb means thumb2 and that is just as fast as arm mode but uses
less space. All bit distros use this as well.

Michael

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

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