[Xenomai-core] MPC8641D and CONFIG_PPC_MERGE

[Xenomai-core] MPC8641D and CONFIG_PPC_MERGE

[Jeff Koftinoff]

Hi Everyone. I would really like to get Xenomai working on the new 
Freescale 8641D dual core G4.

I see that for linux 2.6.19, Xenomai does not support CONFIG_PPC_MERGE 
or architectures=powerpc instead of 'ppc'.

Please forgive my ignorance; What exactly is the difference between 
arch=ppc and arch=powerpc?

What is involved in changing adeos to work under arch=powerpc on the 
8641D in single core mode?

How much more work is involved in changing adeos to support SMP on powerpc?

Thanks for any information;

Best Regards,

Jeff Koftinoff
jeffk@domain.hid

Re: [Xenomai-core] MPC8641D and CONFIG_PPC_MERGE

[Heikki Lindholm]

Jeff Koftinoff kirjoitti:
> Hi Everyone. I would really like to get Xenomai working on the new 
> Freescale 8641D dual core G4.
> 
> I see that for linux 2.6.19, Xenomai does not support CONFIG_PPC_MERGE 
> or architectures=powerpc instead of 'ppc'.

Weren't there some experimental powerpc ports already posted some time 
ago (by Wolfgang, I think)? See the list archive.

> Please forgive my ignorance; What exactly is the difference between 
> arch=ppc and arch=powerpc?
> 
> What is involved in changing adeos to work under arch=powerpc on the 
> 8641D in single core mode?
> 
> How much more work is involved in changing adeos to support SMP on powerpc?

The 64-bit powerpc target is under powerpc and supports SMP. The work 
required somewhat depends on the specific architecture implementation of 
SMP, but shouldn't be too difficult.

-- Heikki Lindholm

Re: [Xenomai-core] MPC8641D and CONFIG_PPC_MERGE

[Wolfgang Grandegger]

Heikki Lindholm wrote:
> Jeff Koftinoff kirjoitti:
>> Hi Everyone. I would really like to get Xenomai working on the new 
>> Freescale 8641D dual core G4.
>>
>> I see that for linux 2.6.19, Xenomai does not support CONFIG_PPC_MERGE 
>> or architectures=powerpc instead of 'ppc'.
> 
> Weren't there some experimental powerpc ports already posted some time 
> ago (by Wolfgang, I think)? See the list archive.

I started porting to the powerpc tree some time ago but realized that it 
was not straight-forward. My quick hack didn't boot and then I stopped 
because of lack of free time.

>> Please forgive my ignorance; What exactly is the difference between 
>> arch=ppc and arch=powerpc?

Mainly the use of the generic IRQ layer and time of day. It requires an
in-depth review and design of the corresponding Adeos/I-pipe 
implementation. Well, the general design is already there for x86 
implemented by Philippe but needs to be adapted. Nevertheless, the port 
is planned for the near future. Funding would help, of course.

>> What is involved in changing adeos to work under arch=powerpc on the 
>> 8641D in single core mode?
>>
>> How much more work is involved in changing adeos to support SMP on 
>> powerpc?
> 
> The 64-bit powerpc target is under powerpc and supports SMP. The work 
> required somewhat depends on the specific architecture implementation of 
> SMP, but shouldn't be too difficult.

That's also my impression, and a system for porting and testing is also 
required.

Wolfgang.

Re: [Xenomai-core] MPC8641D and CONFIG_PPC_MERGE

[Jeff Koftinoff]

Thank you for your responses, Wolfgang.

I still have some confusion; I was able to build and run a xenomai 2.2.0 
patched linux 2.6.14 kernel on a Apple EMac, which has a 7447A processor 
in it - with no changes, and was able to get good latency results in my 
tests.

I am currently playing with a 8641D dual core power pc, it is basically 
two 7448 processors in one package which is almost identical to the 
7447A, along with peripherals (ethernet/serial/pcie).  Yet I can't seem 
to get xenomai compiled for it, even in non-smp mode.
The 8641D needs a newer kernel than 2.6.14 ( 2.6.19 is okay ). 

What should I do?

Regards,
Jeff Koftinoff

Wolfgang Grandegger wrote:
> Heikki Lindholm wrote:
>> Jeff Koftinoff kirjoitti:
>>> Hi Everyone. I would really like to get Xenomai working on the new 
>>> Freescale 8641D dual core G4.
>>>
>>> I see that for linux 2.6.19, Xenomai does not support 
>>> CONFIG_PPC_MERGE or architectures=powerpc instead of 'ppc'.
>>
>> Weren't there some experimental powerpc ports already posted some 
>> time ago (by Wolfgang, I think)? See the list archive.
>
> I started porting to the powerpc tree some time ago but realized that 
> it was not straight-forward. My quick hack didn't boot and then I 
> stopped because of lack of free time.
>
>>> Please forgive my ignorance; What exactly is the difference between 
>>> arch=ppc and arch=powerpc?
>
> Mainly the use of the generic IRQ layer and time of day. It requires an
> in-depth review and design of the corresponding Adeos/I-pipe 
> implementation. Well, the general design is already there for x86 
> implemented by Philippe but needs to be adapted. Nevertheless, the 
> port is planned for the near future. Funding would help, of course.
>
>>> What is involved in changing adeos to work under arch=powerpc on the 
>>> 8641D in single core mode?
>>>
>>> How much more work is involved in changing adeos to support SMP on 
>>> powerpc?
>>
>> The 64-bit powerpc target is under powerpc and supports SMP. The work 
>> required somewhat depends on the specific architecture implementation 
>> of SMP, but shouldn't be too difficult.
>
> That's also my impression, and a system for porting and testing is 
> also required.
>
> Wolfgang.
>

Re: [Xenomai-core] MPC8641D and CONFIG_PPC_MERGE

[Heikki Lindholm]

Jeff Koftinoff kirjoitti:
> Thank you for your responses, Wolfgang.
> 
> I still have some confusion; I was able to build and run a xenomai 2.2.0 
> patched linux 2.6.14 kernel on a Apple EMac, which has a 7447A processor 
> in it - with no changes, and was able to get good latency results in my 
> tests.

I think the older kernels still supported Apple hardware under the "ppc" 
arch, but in the more recent kernels it's moved to the "powerpc" arch.

> I am currently playing with a 8641D dual core power pc, it is basically 
> two 7448 processors in one package which is almost identical to the 
> 7447A, along with peripherals (ethernet/serial/pcie).  Yet I can't seem 
> to get xenomai compiled for it, even in non-smp mode.
> The 8641D needs a newer kernel than 2.6.14 ( 2.6.19 is okay ).
> What should I do?

If you have followed Linux kernel development and understand the new 
genirq stuff (and eventually irq threads), or are willing to dig into 
it, then why not start a brave porting effort and try to, for example, 
first make your eMac work on newer kernels with adeos/xenomai stuff applied.

-- Heikki Lindholm