Re: [Xenomai] Question about 2.6.2.1

Re: [Xenomai] Question about 2.6.2.1

[Gregory Perry]

How do I go about finding out what the most recent kernel for ARM that is supported by 2.6.2.1?  Is it still 3.2.21?  Can someone point me to the file in the Xenomai distro which describes the most recent kernel released with each Xenomai?

I am going to take the plunge and patch each release up to 3.2.21 on the BeagleBone with the TI support patches, and then attempt a Xenomai integration on that optimized TI kernel.

Re: [Xenomai] Question about 2.6.2.1

[Gilles Chanteperdrix]

On 02/11/2013 06:23 AM, Gregory Perry wrote:

> How do I go about finding out what the most recent kernel for ARM
> that is supported by 2.6.2.1?  Is it still 3.2.21?  Can someone point
> me to the file in the Xenomai distro which describes the most recent
> kernel released with each Xenomai?
> 
> I am going to take the plunge and patch each release up to 3.2.21 on
> the BeagleBone with the TI support patches, and then attempt a
> Xenomai integration on that optimized TI kernel.


Simply have a look at the ksrc/arch/arm/patches directory.

-- 
                                                                Gilles.

Re: [Xenomai] Question about 2.6.2.1

[Gregory Perry]

>________________________________________
>From: Gilles Chanteperdrix [gilles.chanteperdrix@xenomai.org]
>Sent: Monday, February 11, 2013 2:37 AM
>To: Gregory Perry
>Cc: xenomai@xenomai.org
>Subject: Re: [Xenomai] Question about 2.6.2.1
>
>On 02/11/2013 06:23 AM, Gregory Perry wrote:
>
>> How do I go about finding out what the most recent kernel for ARM
>> that is supported by 2.6.2.1?  Is it still 3.2.21?  Can someone point
>> me to the file in the Xenomai distro which describes the most recent
>> kernel released with each Xenomai?
>>
>> I am going to take the plunge and patch each release up to 3.2.21 on
>> the BeagleBone with the TI support patches, and then attempt a
>> Xenomai integration on that optimized TI kernel.
>
>
>Simply have a look at the ksrc/arch/arm/patches directory.
>
>--
>                                                                Gilles.

Thanks much Gilles

Re: [Xenomai] Question about 2.6.2.1

[Gregory Perry]

>________________________________________
>From: Michael Haberler [mah@mah.priv.at]
>Sent: Monday, February 11, 2013 6:06 AM
>To: Gregory Perry
>Subject: Re: [Xenomai] Question about 2.6.2.1
>
>Am 11.02.2013 um 06:23 schrieb Gregory Perry:
>
>> How do I go about finding out what the most recent kernel for ARM that is supported by 2.6.2.1?  Is it still 3.2.21?  Can someone point me to the file in the Xenomai >distro which describes the most recent kernel released with each Xenomai?
>>
>> I am going to take the plunge and patch each release up to 3.2.21 on the BeagleBone with the TI support patches, and then attempt a Xenomai integration on that >optimized TI kernel.
>
>are you aware of this:
>
>http://wiki.linuxcnc.org/cgi-bin/wiki.pl?BeagleboneDevsetup
>
>and this
>
>http://git.mah.priv.at/gitweb?p=linuxcnc-kernel.git;a=summary ?
>
>- Michael

Yeah I've been following the EMC project for a while now as well as other initiatives to build Xenomai on the BeagleBone and BeagleBoard.  In fact I think that Stephan Kappertz has posted the best integration to date for the BeagleBone and Xenomai on Angstrom; however I am not aware of anyone to date that's been able to successfully integrate all of the TI patches into the kernel and then patch the kernel with Xenomai.  So either you get the BeagleBone kernel with all all TI optimizations, or a generic kernel with Xenomai support, but not both.  Typically this breaks support for additional things in the kernel, probably sysfs support for sysfs-based GPIO access and PWM toggling etc.

So according to Robert Nelson (the TI patch maintainer for the BeagleBoard/Bone kernel), the only way to do this is to start with the Aragon kernel, apply each kernel revision patch from 3.2.0 -> 3.2.21, with the TI patch branch applied at each to arrive at a 3.2.21 kernel that has all of the TI patches integrated.

I think this is the right approach, or maybe I am just shooting fish in a barrel here with this.

Re: [Xenomai] Question about 2.6.2.1

[Gilles Chanteperdrix]

On 02/11/2013 06:50 PM, Gregory Perry wrote:
>> ________________________________________ From: Michael Haberler
>> [mah@mah.priv.at] Sent: Monday, February 11, 2013 6:06 AM To:
>> Gregory Perry Subject: Re: [Xenomai] Question about 2.6.2.1
>> 
>> Am 11.02.2013 um 06:23 schrieb Gregory Perry:
>> 
>>> How do I go about finding out what the most recent kernel for ARM
>>> that is supported by 2.6.2.1?  Is it still 3.2.21?  Can someone
>>> point me to the file in the Xenomai >distro which describes the
>>> most recent kernel released with each Xenomai?
>>> 
>>> I am going to take the plunge and patch each release up to 3.2.21
>>> on the BeagleBone with the TI support patches, and then attempt a
>>> Xenomai integration on that >optimized TI kernel.
>> 
>> are you aware of this:
>> 
>> http://wiki.linuxcnc.org/cgi-bin/wiki.pl?BeagleboneDevsetup
>> 
>> and this
>> 
>> http://git.mah.priv.at/gitweb?p=linuxcnc-kernel.git;a=summary ?
>> 
>> - Michael
> 
> Yeah I've been following the EMC project for a while now as well as
> other initiatives to build Xenomai on the BeagleBone and BeagleBoard.
> In fact I think that Stephan Kappertz has posted the best integration
> to date for the BeagleBone and Xenomai on Angstrom; however I am not
> aware of anyone to date that's been able to successfully integrate
> all of the TI patches into the kernel and then patch the kernel with
> Xenomai.  So either you get the BeagleBone kernel with all all TI
> optimizations, or a generic kernel with Xenomai support, but not
> both.  Typically this breaks support for additional things in the
> kernel, probably sysfs support for sysfs-based GPIO access and PWM
> toggling etc.

sysfs-base GPIO access and PWM is a bad example, as except for powering
on/off things once in a while, you do not really want the overhead of a
system call for toggling a GPIO, besides the fact that it would cause a
real-time task to cease being a real-time task.

> 
> So according to Robert Nelson (the TI patch maintainer for the
> BeagleBoard/Bone kernel), the only way to do this is to start with
> the Aragon kernel, apply each kernel revision patch from 3.2.0 ->
> 3.2.21, with the TI patch branch applied at each to arrive at a
> 3.2.21 kernel that has all of the TI patches integrated.
> 
> I think this is the right approach, or maybe I am just shooting fish
> in a barrel here with this.

The right approach is to get the code from the TI branch merged into the
mainline kernel. Failing that, provide a pre and post patches (like
Michael provided) for the target kernel, patches which we can ship with
Xenomai. Merging the I-pipe with a vendor kernel should not be a really
hard job, you should only get conflicts between the processor-specific
files modified by the I-pipe kernel, which should be say, less than 10
files.

-- 
					    Gilles.