[Xenomai] Xenomai on Cortex R (or Rreal Time) family

[Xenomai] Xenomai on Cortex R (or Rreal Time) family

[mobin Motallebizadeh]

 Hi
can I build xenomai for armv7-r architecture? 
I can't see this mentioned anywhere (surprisingly!)
Is it same as other MMU-less archs(nios II ,e.g.)?
thanks in advance 		 	   		  

Re: [Xenomai] Xenomai on Cortex R (or Rreal Time) family

[Lennart Sorensen]

On Thu, Oct 02, 2014 at 02:28:33PM +0000, mobin Motallebizadeh wrote:
> can I build xenomai for armv7-r architecture? 
> I can't see this mentioned anywhere (surprisingly!)
> Is it same as other MMU-less archs(nios II ,e.g.)?
> thanks in advance 		 	   		  

Cortex-R (armv7-r) is MMU-less, so it would have to run a kernel with
no mmu enabled (which linux does support for arm as far as I recall).

I see xenomai works with blackfin which is MMU-less.  Not sure if anyone
has used xenomai with arm without an mmu, but at least in theory it
could be done then.

-- 
Len Sorensen

Re: [Xenomai] Xenomai on Cortex R (or Rreal Time) family

[Gilles Chanteperdrix]

On 10/02/2014 04:28 PM, mobin Motallebizadeh wrote:
>  Hi
> can I build xenomai for armv7-r architecture? 
> I can't see this mentioned anywhere (surprisingly!)
> Is it same as other MMU-less archs(nios II ,e.g.)?

The first question to ask is: do you have a Linux kernel for this
processor? because Xenomai needs Linux to run.


-- 
                                                                Gilles.

Re: [Xenomai] Xenomai on Cortex R (or Rreal Time) family

[Philippe Gerum]

On 10/02/2014 04:41 PM, Lennart Sorensen wrote:
> On Thu, Oct 02, 2014 at 02:28:33PM +0000, mobin Motallebizadeh wrote:
>> can I build xenomai for armv7-r architecture? 
>> I can't see this mentioned anywhere (surprisingly!)
>> Is it same as other MMU-less archs(nios II ,e.g.)?
>> thanks in advance 		 	   		  
> 
> Cortex-R (armv7-r) is MMU-less, so it would have to run a kernel with
> no mmu enabled (which linux does support for arm as far as I recall).
> 
> I see xenomai works with blackfin which is MMU-less.  Not sure if anyone
> has used xenomai with arm without an mmu, but at least in theory it
> could be done then.
> 

There is absolutely no issue with running Xenomai 2.6.x or 3.x/cobalt
over mmu-less, it's a maintained configuration (bfin has been supported
since ages). The "only" issue, is to get a proper kernel implementing
the I-pipe which may require some work with vendor-originated kernels.

-- 
Philippe.

Re: [Xenomai] Xenomai on Cortex R (or Rreal Time) family

[mobin Motallebizadeh]

> On 10/02/2014 04:28 PM, mobin Motallebizadeh wrote:
> >  Hi
> > can I build xenomai for armv7-r architecture? 
> > I can't see this mentioned anywhere (surprisingly!)
> > Is it same as other MMU-less archs(nios II ,e.g.)?
> 
> The first question to ask is: do you have a Linux kernel for this
> processor? because Xenomai needs Linux to run.
> 
> 
> -- 
>                                                                 Gilles.

there's uClinux which can support xenomai (as u mentioned in docs) and cortex-r family is limited to.
 		 	   		  

Re: [Xenomai] Xenomai on Cortex R (or Rreal Time) family

[Gilles Chanteperdrix]

On Fri, Oct 03, 2014 at 03:50:10AM +0000, mobin Motallebizadeh wrote:
>
>
>
>
> > On 10/02/2014 04:28 PM, mobin Motallebizadeh wrote:
> > >  Hi
> > > can I build xenomai for armv7-r architecture?
> > > I can't see this mentioned anywhere (surprisingly!)
> > > Is it same as other MMU-less archs(nios II ,e.g.)?
> >
> > The first question to ask is: do you have a Linux kernel for this
> > processor? because Xenomai needs Linux to run.
> >
> >
>
> there's uClinux which can support xenomai (as u mentioned in docs) and cortex-r family is limited to.

If it is not the mainline Linux, and it does not share code with the
ARM Linux port, then as Philippe indicated a new port of the I-pipe
patch is needed, but that is doable.

--
					    Gilles.

Re: [Xenomai] Xenomai on Cortex R (or Rreal Time) family

[Richard Cochran]

On Thu, Oct 02, 2014 at 04:48:16PM +0200, Gilles Chanteperdrix wrote:
> On 10/02/2014 04:28 PM, mobin Motallebizadeh wrote:
> >  Hi
> > can I build xenomai for armv7-r architecture? 
> > I can't see this mentioned anywhere (surprisingly!)
> > Is it same as other MMU-less archs(nios II ,e.g.)?
> 
> The first question to ask is: do you have a Linux kernel for this
> processor? because Xenomai needs Linux to run.

There is some main line support for Cortex-M3, for the Energy Micro
development kit. See Uwe Kleine-König's tree at

   http://git.pengutronix.de/?p=ukl/linux.git

I have never heard of Linux running on a Cortex-R at all.

HTH,
Richard

Re: [Xenomai] Xenomai on Cortex R (or Rreal Time) family

[Gilles Chanteperdrix]

On 10/10/2014 03:25 PM, Richard Cochran wrote:
> On Thu, Oct 02, 2014 at 04:48:16PM +0200, Gilles Chanteperdrix wrote:
>> On 10/02/2014 04:28 PM, mobin Motallebizadeh wrote:
>>>  Hi
>>> can I build xenomai for armv7-r architecture? 
>>> I can't see this mentioned anywhere (surprisingly!)
>>> Is it same as other MMU-less archs(nios II ,e.g.)?
>>
>> The first question to ask is: do you have a Linux kernel for this
>> processor? because Xenomai needs Linux to run.
> 
> There is some main line support for Cortex-M3, for the Energy Micro
> development kit. See Uwe Kleine-König's tree at
> 
>    http://git.pengutronix.de/?p=ukl/linux.git

Well, if it is someone's (other than Linus') tree, it is not mainline :-)

I have worked with Cortex-M3 (TI stellaris family), and as far as I
remember, it has very different behaviour from cortex-A for exceptions,
irqs (the irq controller is integrated in the processor irq path, there
is one irq address for each irq in the vector table, much like x86), and
the like. So, at minimum some changes in entry.S would be needed for
Xenomai to run.


-- 
                                                                Gilles.

Re: [Xenomai] Xenomai on Cortex R (or Rreal Time) family

[Richard Cochran]

On Fri, Oct 10, 2014 at 05:10:37PM +0200, Gilles Chanteperdrix wrote:
> Well, if it is someone's (other than Linus') tree, it is not mainline :-)

Just to be clear: I think most everything has gone main line.  But if
anything is missing, check Uwe's tree.  Also, you still need a simple
boot loader and user land, so try this:

http://git-public.pengutronix.de/?p=OSELAS.BSP-EnergyMicro-Gecko.git;a=summary

Anyhow, about Cortex-R, I can offer this:

1. Cortex-M is now working in main line for efm32.
2. No one is interested in Linux Cortex-M (seems to me)
3. Cortex-R is not supported in any Linux at all (AFAICT)

Thanks,
Richard

Re: [Xenomai] Xenomai on Cortex R (or Rreal Time) family

[Gilles Chanteperdrix]

On Sat, Oct 11, 2014 at 08:54:04PM +0200, Richard Cochran wrote:
> On Fri, Oct 10, 2014 at 05:10:37PM +0200, Gilles Chanteperdrix wrote:
> > Well, if it is someone's (other than Linus') tree, it is not mainline :-)
> 
> Just to be clear: I think most everything has gone main line.  But if
> anything is missing, check Uwe's tree.  Also, you still need a simple
> boot loader and user land, so try this:
> 
> http://git-public.pengutronix.de/?p=OSELAS.BSP-EnergyMicro-Gecko.git;a=summary
> 
> Anyhow, about Cortex-R, I can offer this:
> 
> 1. Cortex-M is now working in main line for efm32.
> 2. No one is interested in Linux Cortex-M (seems to me)

Well, a lot of Cortex M are running code from very small NOR
flashes, with very little RAM as well. So, they definitely can not
run Linux. Having worked with such processors, and with FreeRTOS, let
us just say I was motivated by a port of Xenomai POSIX skin on bare
metal. But this has probably become a little harder with Xenomai 3
than with Xenomai 2. And I never found time to do it anyway.

> 3. Cortex-R is not supported in any Linux at all (AFAICT)

I thought so, but mobin seems to say a uCLinux port exists.

This page:
http://elinux.org/Processors

mentions it.

-- 
					    Gilles.

Re: [Xenomai] Xenomai on Cortex R (or Rreal Time) family

[Lennart Sorensen]

On Thu, Oct 02, 2014 at 02:22:35PM +0000, mobin Motallebizadeh wrote:
>  OMG! where should I ask it? I sent this to xenomai_at_org mail.sorry I always did this way!!

Well you did it by replying to a thread rather than sending a new message
to xenomai@xenomai.org (changing the subject is NOT the same thing as
creating a new thread).  When you hit reply your email client inserts
a tag in the mssage saying which other message it was a reply to.

-- 
Len Sorensen

Re: [Xenomai] Xenomai on Cortex R (or Rreal Time) family

[mobin Motallebizadeh]

 
> Date: Thu, 2 Oct 2014 16:00:57 +0200
> From: gilles.chanteperdrix@xenomai.org
> To: mobin.seven@live.com; xenomai@xenomai.org
> Subject: Re: [Xenomai] Xenomai on Cortex R (or Rreal Time) family
> 
> On 10/02/2014 03:56 PM, mobin Motallebizadeh wrote:
> > Hi
> > can I build xenomai for armv7-r architecture? 
> > I can't see this mentioned anywhere (surprisingly!)
> > Is it same as other MMU-less archs(nios II ,e.g.)?
> > thanks in advance
> 
> This is a very legitimate question, but why are you hi-jacking a
> discussion thread to ask it? Please do not reply a mail from another
> discussion to ask a new question, this breaks archives for people who
> want to browse the archives by discussion thread.
> 
> -- 
>                                                                 Gilles.
 OMG! where should I ask it? I sent this to xenomai_at_org mail.sorry I always did this way!! 		 	   		  

Re: [Xenomai] Xenomai on Cortex R (or Rreal Time) family

[Gilles Chanteperdrix]

On 10/02/2014 03:56 PM, mobin Motallebizadeh wrote:
> Hi
> can I build xenomai for armv7-r architecture? 
> I can't see this mentioned anywhere (surprisingly!)
> Is it same as other MMU-less archs(nios II ,e.g.)?
> thanks in advance

This is a very legitimate question, but why are you hi-jacking a
discussion thread to ask it? Please do not reply a mail from another
discussion to ask a new question, this breaks archives for people who
want to browse the archives by discussion thread.

-- 
                                                                Gilles.

[Xenomai] Xenomai on Cortex R (or Rreal Time) family

[mobin Motallebizadeh]

Hi
can I build xenomai for armv7-r architecture? 
I can't see this mentioned anywhere (surprisingly!)
Is it same as other MMU-less archs(nios II ,e.g.)?
thanks in advance