MPC5554 Rtems port

[John Wood]

Hi Thomas,

I haven't gotten into too much detail regarding the SPE patches.  I got
my compiler sources for the
MPC5554 family from P&E microsystems.  It is pretty much the
powerpc-eabi but with some extensions for supporting the extended
instruction associated with the SPE APU.

I can probably start with the powerpc-eabi target and ignore, for the
moment, the SPE.  I think the biggest change would be to the exception
processing.  This is a complete (for the better) overhaul.  It seems
like yet another addition to powerpc exception processing would be
necessary.  Possibly a booke_exception_processing or something to that
effect.

When I looked at the gnu sources the powerpc-eabispe was a new target.
It only built libraries for the 7400 family.  I added powerpc-rtemsspe.
It was fairly simple and got both binutils and gcc to build without a
problem but I havent completed a simple port close enough to try
building rtems libraries just yet.

I will start working from 4.6.99.x as you recommend.  I think I have
most of the exception stuff figured out and will ignore for the time
being the SPE extensions.  

What would be the best version of tools to work with for development so
I am on the same page as everyone.
I can probably patch those when the time comes if the SPE target is not
integrated by then.

My current plan is to add CPU support for the MPC5500 family of
processors and a BSP for the phycore board.  This is pretty much on
hobby time so I don't know how fast it will go.

As for SPE support to the OS, it looks like saving the upper half of the
GPRs and the few new status registers would be simplest but not the most
efficient.  


Thanks,
John 

-----Original Message-----
From: Thomas Doerfler [mailto:Thomas.Doerfler at embedded-brains.de] 
Sent: Tuesday, August 15, 2006 2:39 PM
To: John Wood
Cc: RTEMS - Mailing List
Subject: Re: MPC5554 Rtems port

John,

a port to the MPC5554 would be a fine addition to the pool of supported
processors. There is a port for the MPC5xx family, but I think the
differences concerning peripherals and the core are too big to really
benefit from it.

John Wood schrieb:
>  
> I have built a toolset based on GCC3.4.4 since this is one that I had 
> sources and patches for and made what I believe are the necessary 
> changes for rtems
>
> I created target for the compiler powerpc-rtemsspe modeled on the
powerpc-eabispe
> target I got with my developement kit.
>

What are the patches about, and can they be integrated into the standard
gcc source tree? RTEMS in general uses the same compiler version for all
target architectures, so it would be really prefereable to have the
MPC5554 specific stuff integrated into GCC.

> I am currently working with version 4.6.6.  

It might be better to use the "almost-4.7" version 4.6.99.x for your
development, because 4.6.6 is evolving into a stable (maintenance only)
version.

>  
> What is the current state of the current branch for rtems and tools 
> regarding spe extentions for the ppc family?  Is this a processor that

> you would be interested in having a port?

Currently there is no support for SPE. IMO, the things interesting for
the OS concerning the SPE would be some (control) registers, possibly
some new exceptions. AFAIK, the SPE uses the "normal" general purpose
registers for data, so there is no new bunch of registers to swap.

>  
>  
> I am just getting my head wrapped around what is necessary.

I also have some MPC5554 equipment (Axiom Demo Board, and soon a phycore
MPC5554 board, Lauterbach Trace32 for MPC5554 as debugger...). So if I
can be of help for your port, please let me know.

wkr,
Thomas Doerfler.


>  
> Thanks,
> John


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