[Buildroot] [PATCH 0/2] add support for xtensa back to buildroot

[Buildroot] [PATCH 0/2] add support for xtensa back to buildroot

[Chris Zankel]

Hi,

It would be great if you could add support for Xtensa back to buildroot.
I understand that it was removed because it required a lot of additional
files and special handling, which became obsolete and hard to maintain
over time.
These two patches are much more aligned with other architectures with only
very minimal overhead. I also just recently updated uClibc and can build
buildroot out of the box, so we can now better support and maintain it.

Thanks,
-Chris

----------------------------------------------------------------
Chris Zankel (2):
      xtensa: add support for the Xtensa architecture
      xtensa: support configurable processor configurations

 arch/Config.in                  |    8 ++++++++
 arch/Config.in.common           |    1 +
 arch/Config.in.xtensa           |   30 ++++++++++++++++++++++++++++++
 linux/Config.in                 |    3 ++-
 package/autoconf/Config.in      |    6 ++++--
 package/automake/Config.in      |    6 ++++--
 package/binutils/binutils.mk    |    9 +++++++++
 package/ltrace/Config.in        |    1 +
 package/perl/Config.in          |    4 +++-
 toolchain/gcc/gcc-uclibc-4.x.mk |    4 ++++
 toolchain/gdb/gdb.mk            |    4 ++++
 toolchain/toolchain-common.in   |    2 +-
 toolchain/uClibc/uclibc.mk      |    1 +
 13 files changed, 72 insertions(+), 7 deletions(-)
 create mode 100644 arch/Config.in.xtensa

[Buildroot] [PATCH 0/2] add support for xtensa back to buildroot

[Thomas Petazzoni]

Dear Chris Zankel,

On Wed, 07 Nov 2012 19:38:14 -0800, Chris Zankel wrote:

> It would be great if you could add support for Xtensa back to buildroot.
> I understand that it was removed because it required a lot of additional
> files and special handling, which became obsolete and hard to maintain
> over time.
> These two patches are much more aligned with other architectures with only
> very minimal overhead. I also just recently updated uClibc and can build
> buildroot out of the box, so we can now better support and maintain it.

I just skimmed through the patches, but it indeed looks a lot more
reasonable than the support we originally had for Xtensa, thanks for
this work!. One thing that should be added is to make sure that the
Crosstool-NG backend cannot be selected for Xtensa, as it doesn't
support this architecture.

Also, the issue we had with the original Xtensa implementation is that
the original submitters sent some patches that we merged, and
subsequently never maintained them. Do you have plans to use this
Xtensa architecture on a regular basis, and help us fixing build issues
related to this architecture? Of course, we don't require you any sort
of strict commitment or anything like that, I'd just like to know how
much you'll be using this architecture.

Thanks again for having worked on this,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[Buildroot] [PATCH 0/2] add support for xtensa back to buildroot

[Chris Zankel]

Hi Thomas,

I understand your concern, and I guess it won't help that I had patches
to clean up Buildroot for Xtensa laying around for over a year :-[ So,
my promise would be to actually submit patches when I have them.

Part of the problem was that it wasn't just Buildroot, but other parts
(uClibc, kernel, etc.) were also missing or having outdated changes, so
it would have required to push a lot of patches. I have been working to
get those patches in the corresponding trees first, and Buildroot
actually now builds and runs out of the box on Xtensa with just those
two patches and a generic patch for uClibc-snapshot. So, maintainability
and detecting breakage will be much easier, and I intend to verify it on
a more regular basis.

I'll send an updated version of the two patches where Crosstool-NG is
disabled for Xtensa.

Thanks,
-Chris




On 11/07/2012 11:22 PM, Thomas Petazzoni wrote:
> Dear Chris Zankel,
>
> On Wed, 07 Nov 2012 19:38:14 -0800, Chris Zankel wrote:
>
>> It would be great if you could add support for Xtensa back to buildroot.
>> I understand that it was removed because it required a lot of additional
>> files and special handling, which became obsolete and hard to maintain
>> over time.
>> These two patches are much more aligned with other architectures with only
>> very minimal overhead. I also just recently updated uClibc and can build
>> buildroot out of the box, so we can now better support and maintain it.
> I just skimmed through the patches, but it indeed looks a lot more
> reasonable than the support we originally had for Xtensa, thanks for
> this work!. One thing that should be added is to make sure that the
> Crosstool-NG backend cannot be selected for Xtensa, as it doesn't
> support this architecture.
>
> Also, the issue we had with the original Xtensa implementation is that
> the original submitters sent some patches that we merged, and
> subsequently never maintained them. Do you have plans to use this
> Xtensa architecture on a regular basis, and help us fixing build issues
> related to this architecture? Of course, we don't require you any sort
> of strict commitment or anything like that, I'd just like to know how
> much you'll be using this architecture.
>
> Thanks again for having worked on this,
>
> Thomas

[Buildroot] [PATCH 0/2] add support for xtensa back to buildroot

[Thomas Petazzoni]

Hello Chris,

On Thu, 08 Nov 2012 20:49:19 -0800, Chris Zankel wrote:

> I understand your concern, and I guess it won't help that I had patches
> to clean up Buildroot for Xtensa laying around for over a year :-[ So,
> my promise would be to actually submit patches when I have them.
> 
> Part of the problem was that it wasn't just Buildroot, but other parts
> (uClibc, kernel, etc.) were also missing or having outdated changes, so
> it would have required to push a lot of patches. I have been working to
> get those patches in the corresponding trees first, and Buildroot
> actually now builds and runs out of the box on Xtensa with just those
> two patches and a generic patch for uClibc-snapshot. So, maintainability
> and detecting breakage will be much easier, and I intend to verify it on
> a more regular basis.
> 
> I'll send an updated version of the two patches where Crosstool-NG is
> disabled for Xtensa.

Excellent, sounds good.

I've also seen that Qemu has an Xtensa support. It would be nice if you
could create a qemu_xtensa_<somemachine>_defconfig with the necessary
kernel configuration and al (see other qemu_<foo>_defconfig that we
have in configs/) so that other people could build a Xtensa userspace
and run it inside qemu. At the moment, the qemu-system-xtensa supports
the following machines:

$ qemu-system-xtensa -M ?
Supported machines are:
none                 empty machine
lx60                 lx60 EVB (dc232b)
lx200                lx200 EVB (dc232b)
sim                  sim machine (dc232b) (default)

Thanks!

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[Buildroot] [PATCH 0/2] add support for xtensa back to buildroot

[Thomas Petazzoni]

Chris,

On Fri, 9 Nov 2012 09:14:35 +0100, Thomas Petazzoni wrote:

> I've also seen that Qemu has an Xtensa support. It would be nice if you
> could create a qemu_xtensa_<somemachine>_defconfig with the necessary
> kernel configuration and al (see other qemu_<foo>_defconfig that we
> have in configs/) so that other people could build a Xtensa userspace
> and run it inside qemu. At the moment, the qemu-system-xtensa supports
> the following machines:
> 
> $ qemu-system-xtensa -M ?
> Supported machines are:
> none                 empty machine
> lx60                 lx60 EVB (dc232b)
> lx200                lx200 EVB (dc232b)
> sim                  sim machine (dc232b) (default)

Do you have any plans for proposing the support of a Qemu board using
the Xtensa architecture? Qemu already supports 2-3 platforms, so it
would be nice if Buildroot had a defconfig to generate a working system
for one of them.

Thanks,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[Buildroot] [PATCH 0/2] add support for xtensa back to buildroot

[Chris Zankel]

On 11/10/2012 02:57 AM, Thomas Petazzoni wrote:
>> I've also seen that Qemu has an Xtensa support. It would be nice if you
>> could create a qemu_xtensa_<somemachine>_defconfig with the necessary
>> kernel configuration and al (see other qemu_<foo>_defconfig that we
>> have in configs/) so that other people could build a Xtensa userspace
>> and run it inside qemu. At the moment, the qemu-system-xtensa supports
>> the following machines:
>>
>> $ qemu-system-xtensa -M ?
>> Supported machines are:
>> none                 empty machine
>> lx60                 lx60 EVB (dc232b)
>> lx200                lx200 EVB (dc232b)
>> sim                  sim machine (dc232b) (default)
> Do you have any plans for proposing the support of a Qemu board using
> the Xtensa architecture? Qemu already supports 2-3 platforms, so it
> would be nice if Buildroot had a defconfig to generate a working system
> for one of them.
Yes, I'm planing to add support for QEMU, but it will probably take a
bit to understand it better before I have a config and maybe some patches.

Thanks,
-Chris

[Buildroot] [PATCH 0/2] add support for xtensa back to buildroot

[Thomas Petazzoni]

Chris,

On Mon, 12 Nov 2012 12:23:07 -0800, Chris Zankel wrote:

> > Do you have any plans for proposing the support of a Qemu board using
> > the Xtensa architecture? Qemu already supports 2-3 platforms, so it
> > would be nice if Buildroot had a defconfig to generate a working system
> > for one of them.
> Yes, I'm planing to add support for QEMU, but it will probably take a
> bit to understand it better before I have a config and maybe some patches.

Excellent, thanks!

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com