xtensa port maintenance

xtensa port maintenance

[Max Filippov]

Hi.

AFAIK xtensa linux port is currently in bad shape: it doesn't work in the
mainline, it fails to build in the linux-next. The latest working kernels for
xtensa are 2.6.29...31 trees hosted at the git.linux-xtensa.org.

I have a goal to make xtensa arch in the linux mainline usable.
Currently I have a number of patches on top of Linus' tree that allow to build
working allnoconfig, defconfig and allmodconfig kernels for ISS machine with
dc232b and fsf core variants [1]. For the next several weeks I'm planning to
forward-port patches accumulated in linux-xtensa.org git trees and make the
resulting kernels rock-solid. I'd like to restore xtensa participation in the
linux-next. Further (currently undetailed) plans are to bring modern Linux
features to the xtensa port, e.g. device trees.

I have a couple of questions regarding the path of xtensa-specific patches
upstream:
    - which git tree should they be targeted for? Should I set up a tree for
      pull requests, or will patches be picked up into some existing tree?
      (Looks like Linus' tree is the right target. AFAIK previously xtensa
      patches went mostly through akpm tree).

    - which mailing lists should they go to?
      (I guess that besides linux-xtensa@linux-xtensa.org list they should go
      to linux-kernel@vger.kernel.org for general review. Anything else?)

Should you wonder what I am:
I am a member of St.Petersburg Open Source and Linux Lab [2].
My previous contributions to Linux are related to p54spi wireless driver.
I'm also a developer and maintainer of the target-xtensa QEMU port [3].


[1] https://github.com/jcmvbkbc/linux-xtensa
[2] http://osll.spb.ru
[3] http://wiki.qemu.org/Features/Xtensa

-- 
Thanks.
-- Max

Re: xtensa port maintenance

[Chris Zankel]

Hi Max,

On 08/06/2012 04:38 PM, Max Filippov wrote:
> AFAIK xtensa linux port is currently in bad shape: it doesn't work in the
> mainline, it fails to build in the linux-next. The latest working kernels for
> xtensa are 2.6.29...31 trees hosted at the git.linux-xtensa.org.
I wouldn't say it's in bad shape, I just built an vmlinux image from the 
latest tree (3.6.0-rc1), but it might not be very stable. One of the 
major issues is not really the kernel but  there's actually no way to 
build a fairly recent version of the toolchain. I have been using a 
somewhat more recent buildroot version than what is on xtensa-linux.org, 
but even that version of buildroot is rather old now and needed a few 
patches.

The tree on linux-xtensa.org has quite diverted from mainline now. Pete 
has done a great job maintaining those kernel versions, fixing a lot of 
bugs, and adding a ton of new additional features, but it will take 
quite some effort to merge them with the latest kernel.

> I have a goal to make xtensa arch in the linux mainline usable.
Awesome!! Every help is very much appreciated.

> Currently I have a number of patches on top of Linus' tree that allow to build
> working allnoconfig, defconfig and allmodconfig kernels for ISS machine with
> dc232b and fsf core variants [1]. For the next several weeks I'm planning to
You might expect that I'm more than curious to see those changes :-)


> forward-port patches accumulated in linux-xtensa.org git trees and make the
> resulting kernels rock-solid. I'd like to restore xtensa participation in the
> linux-next. Further (currently undetailed) plans are to bring modern Linux
> features to the xtensa port, e.g. device trees.
That would be great. Might I also add that we'd need to have a working 
toolchain and bootable image. For me, buildroot seems to be the quickest 
route here. That would also require possibly adding patches to the 
toolchain and uClibc that are currently missing. There's also the 
bootloader, etc.

> I have a couple of questions regarding the path of xtensa-specific patches
> upstream:
>      - which git tree should they be targeted for? Should I set up a tree for
>        pull requests, or will patches be picked up into some existing tree?
>        (Looks like Linus' tree is the right target. AFAIK previously xtensa
>        patches went mostly through akpm tree).
Yes, Andrew has been very helpful stepping in and adding those patches. 
Most if not all of those patches were fixes because of generic kernel 
changes and not major fixes or changes to the core of the Xtensa port.

Ideally, it would be great if you could create a git tree (I saw you 
already have a version on github already?) that would allow us to look 
over those patches. The goal should be to have a system to build 
toolchain, bootable image, and kernel, so we can run some regression 
tests on either the simulator (qemu) or an actual board. Once we have a 
regression test system in place, we can then add more features and 
funnel those patches either through me or more directly..

What do you think?

If you already have such a system in place, it would be great if you 
could send me some instructions to recreate it locally. We can give you 
also access to the wiki to add any information there.

>      - which mailing lists should they go to?
>        (I guess that besides linux-xtensa@linux-xtensa.org list they should go
>        to linux-kernel@vger.kernel.org for general review. Anything else?)
For now, I would really appreciate if you could hold off sending any 
major patch to the linux-kernel mailing list until we had a chance to 
look over them unless it's some generic patch (fixing an issue because 
of an API change to the kernel, etc.)

Andrew is currently adding all Xtensa patches sent to that list, and I 
would hate having to irritate him having to ask to remove or change 
patches, etc.

> Should you wonder what I am:
> I am a member of St.Petersburg Open Source and Linux Lab [2].
> My previous contributions to Linux are related to p54spi wireless driver.
> I'm also a developer and maintainer of the target-xtensa QEMU port [3].
That's so great!! I didn't know there was a QEMU port for Xtensa.

Bottom line, I hope you agree with me that the kernel, although the most 
fun part, is only one piece of the puzzle, and we also need a running 
system. If you already have that in place, we can jump to the kernel 
fairly quickly.

Thanks,
-Chris

Re: xtensa port maintenance

[Geert Uytterhoeven]

Hi Chris,

On Tue, Aug 7, 2012 at 7:40 AM, Chris Zankel <chris@zankel.net> wrote:
> On 08/06/2012 04:38 PM, Max Filippov wrote:
>> AFAIK xtensa linux port is currently in bad shape: it doesn't work in the
>> mainline, it fails to build in the linux-next. The latest working kernels
>> for
>> xtensa are 2.6.29...31 trees hosted at the git.linux-xtensa.org.
>
> I wouldn't say it's in bad shape, I just built an vmlinux image from the
> latest tree (3.6.0-rc1), but it might not be very stable. One of the major
> issues is not really the kernel but  there's actually no way to build a
> fairly recent version of the toolchain. I have been using a somewhat more
> recent buildroot version than what is on xtensa-linux.org, but even that
> version of buildroot is rather old now and needed a few patches.

Are the errors

| dangerous relocation: l32r: literal placed after use: .literal.unlikely
(http://kisskb.ellerman.id.au/kisskb/buildresult/6845615/)

preventing linking of vmlinux toolchain issues?

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: xtensa port maintenance

[Max Filippov]

On Tue, Aug 7, 2012 at 3:36 PM, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> Hi Chris,
>
> On Tue, Aug 7, 2012 at 7:40 AM, Chris Zankel <chris@zankel.net> wrote:
>> On 08/06/2012 04:38 PM, Max Filippov wrote:
>>> AFAIK xtensa linux port is currently in bad shape: it doesn't work in the
>>> mainline, it fails to build in the linux-next. The latest working kernels
>>> for
>>> xtensa are 2.6.29...31 trees hosted at the git.linux-xtensa.org.
>>
>> I wouldn't say it's in bad shape, I just built an vmlinux image from the
>> latest tree (3.6.0-rc1), but it might not be very stable. One of the major
>> issues is not really the kernel but  there's actually no way to build a
>> fairly recent version of the toolchain. I have been using a somewhat more
>> recent buildroot version than what is on xtensa-linux.org, but even that
>> version of buildroot is rather old now and needed a few patches.
>
> Are the errors
>
> | dangerous relocation: l32r: literal placed after use: .literal.unlikely
> (http://kisskb.ellerman.id.au/kisskb/buildresult/6845615/)
>
> preventing linking of vmlinux toolchain issues?

They may be considered as such (toolchain now adds *.unlikely sections which
was not the case previously), or may not, depending on what one would expect
from the toolchain. I have a fix for that issue:
https://github.com/jcmvbkbc/linux-xtensa/commit/edd7c14132388d5c09c57cf12c76c6631a1e0277

-- 
Thanks.
-- Max

Re: xtensa port maintenance

[Geert Uytterhoeven]

Hi Max,

On Tue, Aug 7, 2012 at 1:56 PM, Max Filippov <jcmvbkbc@gmail.com> wrote:
> On Tue, Aug 7, 2012 at 3:36 PM, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>> On Tue, Aug 7, 2012 at 7:40 AM, Chris Zankel <chris@zankel.net> wrote:
>>> On 08/06/2012 04:38 PM, Max Filippov wrote:
>>>> AFAIK xtensa linux port is currently in bad shape: it doesn't work in the
>>>> mainline, it fails to build in the linux-next. The latest working kernels
>>>> for
>>>> xtensa are 2.6.29...31 trees hosted at the git.linux-xtensa.org.
>>>
>>> I wouldn't say it's in bad shape, I just built an vmlinux image from the
>>> latest tree (3.6.0-rc1), but it might not be very stable. One of the major
>>> issues is not really the kernel but  there's actually no way to build a
>>> fairly recent version of the toolchain. I have been using a somewhat more
>>> recent buildroot version than what is on xtensa-linux.org, but even that
>>> version of buildroot is rather old now and needed a few patches.
>>
>> Are the errors
>>
>> | dangerous relocation: l32r: literal placed after use: .literal.unlikely
>> (http://kisskb.ellerman.id.au/kisskb/buildresult/6845615/)
>>
>> preventing linking of vmlinux toolchain issues?
>
> They may be considered as such (toolchain now adds *.unlikely sections which
> was not the case previously), or may not, depending on what one would expect
> from the toolchain. I have a fix for that issue:
> https://github.com/jcmvbkbc/linux-xtensa/commit/edd7c14132388d5c09c57cf12c76c6631a1e0277

Thanks, that indeed fixes the link issue for me!

BTW, how do you export a "commitdiff" from the github web interface?

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: xtensa port maintenance

[Max Filippov]

On Tue, Aug 7, 2012 at 6:35 PM, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> Hi Max,
>
> On Tue, Aug 7, 2012 at 1:56 PM, Max Filippov <jcmvbkbc@gmail.com> wrote:
>> On Tue, Aug 7, 2012 at 3:36 PM, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>>> On Tue, Aug 7, 2012 at 7:40 AM, Chris Zankel <chris@zankel.net> wrote:
>>>> On 08/06/2012 04:38 PM, Max Filippov wrote:
>>>>> AFAIK xtensa linux port is currently in bad shape: it doesn't work in the
>>>>> mainline, it fails to build in the linux-next. The latest working kernels
>>>>> for
>>>>> xtensa are 2.6.29...31 trees hosted at the git.linux-xtensa.org.
>>>>
>>>> I wouldn't say it's in bad shape, I just built an vmlinux image from the
>>>> latest tree (3.6.0-rc1), but it might not be very stable. One of the major
>>>> issues is not really the kernel but  there's actually no way to build a
>>>> fairly recent version of the toolchain. I have been using a somewhat more
>>>> recent buildroot version than what is on xtensa-linux.org, but even that
>>>> version of buildroot is rather old now and needed a few patches.
>>>
>>> Are the errors
>>>
>>> | dangerous relocation: l32r: literal placed after use: .literal.unlikely
>>> (http://kisskb.ellerman.id.au/kisskb/buildresult/6845615/)
>>>
>>> preventing linking of vmlinux toolchain issues?
>>
>> They may be considered as such (toolchain now adds *.unlikely sections which
>> was not the case previously), or may not, depending on what one would expect
>> from the toolchain. I have a fix for that issue:
>> https://github.com/jcmvbkbc/linux-xtensa/commit/edd7c14132388d5c09c57cf12c76c6631a1e0277
>
> Thanks, that indeed fixes the link issue for me!
>
> BTW, how do you export a "commitdiff" from the github web interface?

Not sure what you mean... You can get raw commitdiff by adding
'.patch' to the URL above:

https://github.com/jcmvbkbc/linux-xtensa/commit/edd7c14132388d5c09c57cf12c76c6631a1e0277.patch

-- 
Thanks.
-- Max

Re: xtensa port maintenance

[Max Filippov]

On Tue, Aug 7, 2012 at 9:40 AM, Chris Zankel <chris@zankel.net> wrote:
> Hi Max,
>
> On 08/06/2012 04:38 PM, Max Filippov wrote:
>>
>> AFAIK xtensa linux port is currently in bad shape: it doesn't work in the
>> mainline, it fails to build in the linux-next. The latest working kernels
>> for
>> xtensa are 2.6.29...31 trees hosted at the git.linux-xtensa.org.
>
> I wouldn't say it's in bad shape, I just built an vmlinux image from the
> latest tree (3.6.0-rc1), but it might not be very stable. One of the major
> issues is not really the kernel but  there's actually no way to build a
> fairly recent version of the toolchain. I have been using a somewhat more
> recent buildroot version than what is on xtensa-linux.org, but even that
> version of buildroot is rather old now and needed a few patches.

I've been using userspace built from the buildroot image hosted on
linux-xtensa.org with gcc-4.4.5 + binutils-2.20.1. I use gcc-4.6.3
(without libc) + binutils-2.22 to build the kernel. I had an impression that
mentioned buildroot was able to produce userspace where LTP could
run successfully for days. So, my initial plan is to use that userspace
with mainline kernel.

[...]

>> forward-port patches accumulated in linux-xtensa.org git trees and make
>> the
>> resulting kernels rock-solid. I'd like to restore xtensa participation in
>> the
>> linux-next. Further (currently undetailed) plans are to bring modern Linux
>> features to the xtensa port, e.g. device trees.
>
> That would be great. Might I also add that we'd need to have a working
> toolchain and bootable image. For me, buildroot seems to be the quickest
> route here. That would also require possibly adding patches to the toolchain
> and uClibc that are currently missing. There's also the bootloader, etc.
>
>> I have a couple of questions regarding the path of xtensa-specific patches
>> upstream:
>>      - which git tree should they be targeted for? Should I set up a tree
>> for
>>        pull requests, or will patches be picked up into some existing
>> tree?
>>        (Looks like Linus' tree is the right target. AFAIK previously
>> xtensa
>>        patches went mostly through akpm tree).
>
> Yes, Andrew has been very helpful stepping in and adding those patches. Most
> if not all of those patches were fixes because of generic kernel changes and
> not major fixes or changes to the core of the Xtensa port.
>
> Ideally, it would be great if you could create a git tree (I saw you already
> have a version on github already?) that would allow us to look over those
> patches. The goal should be to have a system to build toolchain, bootable
> image, and kernel, so we can run some regression tests on either the
> simulator (qemu) or an actual board. Once we have a regression test system
> in place, we can then add more features and funnel those patches either
> through me or more directly..
>
> What do you think?

I have a subset thereof that builds toolchain (without libc) and the kernel.
Buildroot gave me an impression of not very reproducible environment, perhaps
I spent too little time on it. So I made an image and I hope that
pre-built image
may be used, at least in the beginning. I had to lightly patch U-boot hosted on
linux-xtensa.org to make it work on LX60/110/200 QEMU models. I guess we
can start with pre-built image of the bootloader too.

> If you already have such a system in place, it would be great if you could
> send me some instructions to recreate it locally. We can give you also
> access to the wiki to add any information there.

Ok, I'll consolidate my scripts to something that could be used as such
system and share them. I have an editor access to wiki.linux-xtensa.org.

>>      - which mailing lists should they go to?
>>        (I guess that besides linux-xtensa@linux-xtensa.org list they
>> should go
>>        to linux-kernel@vger.kernel.org for general review. Anything else?)
>
> For now, I would really appreciate if you could hold off sending any major
> patch to the linux-kernel mailing list until we had a chance to look over
> them unless it's some generic patch (fixing an issue because of an API
> change to the kernel, etc.)

Ok. I'd like to have even generic patches (my current queue is mostly
generic) reviewed. Do you prefer to read them on github or on the
linux-xtensa mailing list?

>> I'm also a developer and maintainer of the target-xtensa QEMU port [3].
> That's so great!! I didn't know there was a QEMU port for Xtensa.

It's there since qemu-1.0.

> Bottom line, I hope you agree with me that the kernel, although the most fun
> part, is only one piece of the puzzle, and we also need a running system. If
> you already have that in place, we can jump to the kernel fairly quickly.

Completely agree.

-- 
Thanks.
-- Max

Re: xtensa port maintenance

[Geert Uytterhoeven]

Hi Max,

On Tue, Aug 7, 2012 at 5:34 PM, Max Filippov <jcmvbkbc@gmail.com> wrote:
> On Tue, Aug 7, 2012 at 6:35 PM, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>> On Tue, Aug 7, 2012 at 1:56 PM, Max Filippov <jcmvbkbc@gmail.com> wrote:
>>> https://github.com/jcmvbkbc/linux-xtensa/commit/edd7c14132388d5c09c57cf12c76c6631a1e0277
>>
>> Thanks, that indeed fixes the link issue for me!
>>
>> BTW, how do you export a "commitdiff" from the github web interface?
>
> Not sure what you mean... You can get raw commitdiff by adding
> '.patch' to the URL above:
>
> https://github.com/jcmvbkbc/linux-xtensa/commit/edd7c14132388d5c09c57cf12c76c6631a1e0277.patch

Thanks, that's what I was looking for, but couldn't find, so I had to
apply it manually.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [Linux-Xtensa] Re: xtensa port maintenance

[Chris Zankel]

Hi Vadim,

On 08/06/2012 11:00 PM, Vadim Malenboim wrote:
> Hi All,
>
> I've beed dealing with the xtensa port for couple of months and I'd 
> like to contribute / help as much as possible.
>
> I have an ML605 Xilinx Evaluation Board and already succeeded running 
> the clean-stable version from xtensa-linux on it.
>
> I propose doing the testing on this board and any other tasks / issues 
> you think I can help, I'd be glad to.

Excellent!! I'm looking forward to your help.

-Chris

>
> Vadim.
>
> On Tue, Aug 7, 2012 at 8:40 AM, Chris Zankel <chris@zankel.net 
> <mailto:chris@zankel.net>> wrote:
>
>     Hi Max,
>
>
>     On 08/06/2012 04:38 PM, Max Filippov wrote:
>
>         AFAIK xtensa linux port is currently in bad shape: it doesn't
>         work in the
>         mainline, it fails to build in the linux-next. The latest
>         working kernels for
>         xtensa are 2.6.29...31 trees hosted at the
>         git.linux-xtensa.org <http://git.linux-xtensa.org>.
>
>     I wouldn't say it's in bad shape, I just built an vmlinux image
>     from the latest tree (3.6.0-rc1), but it might not be very stable.
>     One of the major issues is not really the kernel but  there's
>     actually no way to build a fairly recent version of the toolchain.
>     I have been using a somewhat more recent buildroot version than
>     what is on xtensa-linux.org <http://xtensa-linux.org>, but even
>     that version of buildroot is rather old now and needed a few patches.
>
>     The tree on linux-xtensa.org <http://linux-xtensa.org> has quite
>     diverted from mainline now. Pete has done a great job maintaining
>     those kernel versions, fixing a lot of bugs, and adding a ton of
>     new additional features, but it will take quite some effort to
>     merge them with the latest kernel.
>
>
>         I have a goal to make xtensa arch in the linux mainline usable.
>
>     Awesome!! Every help is very much appreciated.
>
>
>         Currently I have a number of patches on top of Linus' tree
>         that allow to build
>         working allnoconfig, defconfig and allmodconfig kernels for
>         ISS machine with
>         dc232b and fsf core variants [1]. For the next several weeks
>         I'm planning to
>
>     You might expect that I'm more than curious to see those changes :-)
>
>
>
>         forward-port patches accumulated in linux-xtensa.org
>         <http://linux-xtensa.org> git trees and make the
>         resulting kernels rock-solid. I'd like to restore xtensa
>         participation in the
>         linux-next. Further (currently undetailed) plans are to bring
>         modern Linux
>         features to the xtensa port, e.g. device trees.
>
>     That would be great. Might I also add that we'd need to have a
>     working toolchain and bootable image. For me, buildroot seems to
>     be the quickest route here. That would also require possibly
>     adding patches to the toolchain and uClibc that are currently
>     missing. There's also the bootloader, etc.
>
>
>         I have a couple of questions regarding the path of
>         xtensa-specific patches
>         upstream:
>              - which git tree should they be targeted for? Should I
>         set up a tree for
>                pull requests, or will patches be picked up into some
>         existing tree?
>                (Looks like Linus' tree is the right target. AFAIK
>         previously xtensa
>                patches went mostly through akpm tree).
>
>     Yes, Andrew has been very helpful stepping in and adding those
>     patches. Most if not all of those patches were fixes because of
>     generic kernel changes and not major fixes or changes to the core
>     of the Xtensa port.
>
>     Ideally, it would be great if you could create a git tree (I saw
>     you already have a version on github already?) that would allow us
>     to look over those patches. The goal should be to have a system to
>     build toolchain, bootable image, and kernel, so we can run some
>     regression tests on either the simulator (qemu) or an actual
>     board. Once we have a regression test system in place, we can then
>     add more features and funnel those patches either through me or
>     more directly..
>
>     What do you think?
>
>     If you already have such a system in place, it would be great if
>     you could send me some instructions to recreate it locally. We can
>     give you also access to the wiki to add any information there.
>
>
>              - which mailing lists should they go to?
>                (I guess that besides linux-xtensa@linux-xtensa.org
>         <mailto:linux-xtensa@linux-xtensa.org> list they should go
>                to linux-kernel@vger.kernel.org
>         <mailto:linux-kernel@vger.kernel.org> for general review.
>         Anything else?)
>
>     For now, I would really appreciate if you could hold off sending
>     any major patch to the linux-kernel mailing list until we had a
>     chance to look over them unless it's some generic patch (fixing an
>     issue because of an API change to the kernel, etc.)
>
>     Andrew is currently adding all Xtensa patches sent to that list,
>     and I would hate having to irritate him having to ask to remove or
>     change patches, etc.
>
>
>         Should you wonder what I am:
>         I am a member of St.Petersburg Open Source and Linux Lab [2].
>         My previous contributions to Linux are related to p54spi
>         wireless driver.
>         I'm also a developer and maintainer of the target-xtensa QEMU
>         port [3].
>
>     That's so great!! I didn't know there was a QEMU port for Xtensa.
>
>     Bottom line, I hope you agree with me that the kernel, although
>     the most fun part, is only one piece of the puzzle, and we also
>     need a running system. If you already have that in place, we can
>     jump to the kernel fairly quickly.
>
>     Thanks,
>     -Chris
>
>
>     _______________________________________________
>     linux-xtensa mailing list
>     linux-xtensa@linux-xtensa.org <mailto:linux-xtensa@linux-xtensa.org>
>     http://lists.linux-xtensa.org/mailman/listinfo/linux-xtensa
>
>
>
>
> -- 
> *Vadim Malenboim.*
>       Low Level Software Engineer.
>
>       Cellular : +972(544)925862
>       E-Mail   : vadim@tangotec.com <mailto:vadim@tangotec.com>
>       WEB     : www.tangotec.com <http://www.tangotec.com>
>
>

Re: xtensa port maintenance

[Chris Zankel]

Hi Max,

On 08/07/2012 09:43 AM, Max Filippov wrote:
> On Tue, Aug 7, 2012 at 9:40 AM, Chris Zankel <chris@zankel.net> wrote:
>> Hi Max,
>>
>> On 08/06/2012 04:38 PM, Max Filippov wrote:
>>> AFAIK xtensa linux port is currently in bad shape: it doesn't work in the
>>> mainline, it fails to build in the linux-next. The latest working kernels
>>> for
>>> xtensa are 2.6.29...31 trees hosted at the git.linux-xtensa.org.
>> I wouldn't say it's in bad shape, I just built an vmlinux image from the
>> latest tree (3.6.0-rc1), but it might not be very stable. One of the major
>> issues is not really the kernel but  there's actually no way to build a
>> fairly recent version of the toolchain. I have been using a somewhat more
>> recent buildroot version than what is on xtensa-linux.org, but even that
>> version of buildroot is rather old now and needed a few patches.
> I've been using userspace built from the buildroot image hosted on
> linux-xtensa.org with gcc-4.4.5 + binutils-2.20.1. I use gcc-4.6.3
> (without libc) + binutils-2.22 to build the kernel. I had an impression that
> mentioned buildroot was able to produce userspace where LTP could
> run successfully for days. So, my initial plan is to use that userspace
> with mainline kernel.
Good plan!

> I have a subset thereof that builds toolchain (without libc) and the kernel.
> Buildroot gave me an impression of not very reproducible environment, perhaps
> I spent too little time on it. So I made an image and I hope that
> pre-built image
> may be used, at least in the beginning. I had to lightly patch U-boot hosted on
> linux-xtensa.org to make it work on LX60/110/200 QEMU models. I guess we
> can start with pre-built image of the bootloader too.
I'm not settled on Buildroot, but I had the best experience with it so 
far. OpenEmbedded was a real pain when I used it (it might have improved 
a lot since, though). I once even started my own build system, but it 
became fairly complicated once I wanted to build a bootable system with 
a C library and various packages.




> Ok. I'd like to have even generic patches (my current queue is mostly 
> generic) reviewed. Do you prefer to read them on github or on the 
> linux-xtensa mailing list? 
I looked over them briefly, and only had one or two questions. I'll send 
them tomorrow (our time).


Thanks,
-Chris

Re: xtensa port maintenance

[Arnd Bergmann]

On Monday 06 August 2012, Max Filippov wrote:
> I have a couple of questions regarding the path of xtensa-specific patches
> upstream:
>     - which git tree should they be targeted for? Should I set up a tree for
>       pull requests, or will patches be picked up into some existing tree?
>       (Looks like Linus' tree is the right target. AFAIK previously xtensa
>       patches went mostly through akpm tree).

Setting up a git tree is a good first step if you want to be the official
maintainer, and if you want to get it included into linux-next.

You should also update the maintainers file to list your git tree and name,
and have Chris give you an official approval for that update. My impression
is that he is still occasionally doing work on upstream maintainance but
has moved on to other priorities now. The two of you should decide
together if you want to both be listed as maintainers or one of you
should be a primary contact and the other one doing work in the background.

>     - which mailing lists should they go to?
>       (I guess that besides linux-xtensa@linux-xtensa.org list they should go
>       to linux-kernel@vger.kernel.org for general review. Anything else?)

There is also linux-arch, which has the architecture maintainers. You can
consult that list if you have specific questions about changes that are
going on across architectures.

What kind of changes to you expect to do to the architecture port?
Are there additional platforms you want to get supported? Do you
want to stay compatible with existing user space software, or are you
thinking about moving to the new generic system call interfaces that
would require rebuilding all user land binaries?

	Arnd

Re: xtensa port maintenance

[Chris Zankel]

Hi Arnd,

Given the recent renewed push for Xtensa, I'll step in to feed the 
changes upstream. We might change that in future, though.

Max has volunteered to help bring the Xtensa port up-to-date. Most of 
the recent development was done on outdated trees and never got 
submitted in true kernel-manner (i.e. small changes at a time). It's 
also important to bring the ecosystem (compilers, libraries, etc.) to 
the latest trees, and my understanding is that there's also work going 
on in that area.

I have set up a tree on github for now, and will work close with Max to 
get his changes to Stephen's linux-next tree and eventually Linus' tree. 
I think it's fine to add Max as a second maintainer, so he can help 
filtering patches.

Cheers!
-Chris

On 8/10/12 2:15 PM, Arnd Bergmann wrote:
> On Monday 06 August 2012, Max Filippov wrote:
>> I have a couple of questions regarding the path of xtensa-specific patches
>> upstream:
>>      - which git tree should they be targeted for? Should I set up a tree for
>>        pull requests, or will patches be picked up into some existing tree?
>>        (Looks like Linus' tree is the right target. AFAIK previously xtensa
>>        patches went mostly through akpm tree).
> Setting up a git tree is a good first step if you want to be the official
> maintainer, and if you want to get it included into linux-next.
>

Re: xtensa port maintenance

[Marc Gauthier]

Chris Zankel wrote:
> I have set up a tree on github for now, and will work close
> with Max to get his changes to Stephen's linux-next tree and
> eventually Linus' tree.
> I think it's fine to add Max as a second maintainer [...]

Thanks for helping!


Pete Delaney wrote:
> I'm afraid that doing it piecemeal has failed in the past

Proper patches work fine, was just never done.
(Can discuss off this To: list.)


> Mind anding Marc and myself?

Acting as maintainer involves submitting useful patches over
some period of time.  Right now that's Max and Chris.
(Love to do it, but have plenty as it is on my plate.)

Thanks,
-Marc

RE: xtensa port maintenance

[Rakesh Jain]

Hi Marc,
Is Skype library available for Xtensa Linux port?
They are available for ARM.
Thanks.
-Rakesh

-----Original Message-----
From: Marc Gauthier [mailto:marc@tensilica.com] 
Sent: Friday, August 10, 2012 9:47 PM
To: Pete Delaney; Chris Zankel; Arnd Bergmann; linux-xtensa@linux-xtensa.org; Kirill Krinkin; Stephen Rothwell; Greg KH; linux-kernel@vger.kernel.org; Max Filippov; linux-next@vger.kernel.org; Andrew Morton; Linus Torvalds; 'Mahavir Prasad'; Prasanna Rao; Shimon Edelhaus; Rakesh Jain
Subject: Re: xtensa port maintenance

Chris Zankel wrote:
> I have set up a tree on github for now, and will work close with Max 
> to get his changes to Stephen's linux-next tree and eventually Linus' 
> tree.
> I think it's fine to add Max as a second maintainer [...]

Thanks for helping!


Pete Delaney wrote:
> I'm afraid that doing it piecemeal has failed in the past

Proper patches work fine, was just never done.
(Can discuss off this To: list.)


> Mind anding Marc and myself?

Acting as maintainer involves submitting useful patches over some period of time.  Right now that's Max and Chris.
(Love to do it, but have plenty as it is on my plate.)

Thanks,
-Marc

Re: xtensa port maintenance

[Pete Delaney]

On 08/16/2012 12:38 PM, Rakesh Jain wrote:
> Hi Marc,
> Is Skype library available for Xtensa Linux port?
> They are available for ARM.
I'd also like to know more about the Skype library.

-piet
> Thanks.
> -Rakesh
>
> -----Original Message-----
> From: Marc Gauthier [mailto:marc@tensilica.com] 
> Sent: Friday, August 10, 2012 9:47 PM
> To: Pete Delaney; Chris Zankel; Arnd Bergmann; linux-xtensa@linux-xtensa.org; Kirill Krinkin; Stephen Rothwell; Greg KH; linux-kernel@vger.kernel.org; Max Filippov; linux-next@vger.kernel.org; Andrew Morton; Linus Torvalds; 'Mahavir Prasad'; Prasanna Rao; Shimon Edelhaus; Rakesh Jain
> Subject: Re: xtensa port maintenance
>
> Chris Zankel wrote:
>> I have set up a tree on github for now, and will work close with Max 
>> to get his changes to Stephen's linux-next tree and eventually Linus' 
>> tree.
>> I think it's fine to add Max as a second maintainer [...]
> Thanks for helping!
>
>
> Pete Delaney wrote:
>> I'm afraid that doing it piecemeal has failed in the past
> Proper patches work fine, was just never done.
> (Can discuss off this To: list.)
>
>
>> Mind anding Marc and myself?
> Acting as maintainer involves submitting useful patches over some period of time.  Right now that's Max and Chris.
> (Love to do it, but have plenty as it is on my plate.)
>
> Thanks,
> -Marc
>

RE: xtensa port maintenance

[Rakesh Jain]

Hi Piet and Marc,
Skype does not provide source code for their app.
Skype provides libraries for embedded Linux platforms for ARM architecture such as TV widgets.
If my customer wants to provide Skype application for Xtensa platform, is there way to get Skype library for xtensa?
-Rakesh


-----Original Message-----
From: Pete Delaney [mailto:piet.delaney@gmail.com] 
Sent: Thursday, August 16, 2012 10:35 PM
To: Rakesh Jain
Cc: Marc Gauthier; Chris Zankel; Arnd Bergmann; linux-xtensa@linux-xtensa.org; Kirill Krinkin; Stephen Rothwell; Greg KH; linux-kernel@vger.kernel.org; Max Filippov; linux-next@vger.kernel.org; Andrew Morton; Linus Torvalds; 'Mahavir Prasad'; Prasanna Rao; Shimon Edelhaus
Subject: Re: xtensa port maintenance

On 08/16/2012 12:38 PM, Rakesh Jain wrote:
> Hi Marc,
> Is Skype library available for Xtensa Linux port?
> They are available for ARM.
I'd also like to know more about the Skype library.

-piet
> Thanks.
> -Rakesh
>
> -----Original Message-----
> From: Marc Gauthier [mailto:marc@tensilica.com]
> Sent: Friday, August 10, 2012 9:47 PM
> To: Pete Delaney; Chris Zankel; Arnd Bergmann; 
> linux-xtensa@linux-xtensa.org; Kirill Krinkin; Stephen Rothwell; Greg 
> KH; linux-kernel@vger.kernel.org; Max Filippov; 
> linux-next@vger.kernel.org; Andrew Morton; Linus Torvalds; 'Mahavir 
> Prasad'; Prasanna Rao; Shimon Edelhaus; Rakesh Jain
> Subject: Re: xtensa port maintenance
>
> Chris Zankel wrote:
>> I have set up a tree on github for now, and will work close with Max 
>> to get his changes to Stephen's linux-next tree and eventually Linus'
>> tree.
>> I think it's fine to add Max as a second maintainer [...]
> Thanks for helping!
>
>
> Pete Delaney wrote:
>> I'm afraid that doing it piecemeal has failed in the past
> Proper patches work fine, was just never done.
> (Can discuss off this To: list.)
>
>
>> Mind anding Marc and myself?
> Acting as maintainer involves submitting useful patches over some period of time.  Right now that's Max and Chris.
> (Love to do it, but have plenty as it is on my plate.)
>
> Thanks,
> -Marc
>