Support for MPC852T, any experience ?

Support for MPC852T, any experience ?

[David Jander]

Hi there,

We are developing a board based on the MPC852T (fairly new model,
stripped-down MPC866).
Is there anybody who has sucessfully run linux-ppc on this processor yet (or
it's more advanced MPC866 cousin) ?
Any experience ?
I am specifically interested in using the SPI mode for SCC3 or 4, plus FEC
with an LXT971A phy.
I am new to this mailing list, but I have searched through its archive and
came up with a (simple ?) SPI driver from Navin Bopurri.
Also on the DENX website I found their drivers for 8xx in the 2.4.4 kernel
sources. Has anybody ported those drivers to a more recent version ?
I have now managed to set up a cross-development system comiling the latest
binutils, gcc-3.2.3 (--with-newlib) and the latest linuxppc_2_4_devel kernel
from montavista. I have not been able to find an up to date guide for setting
up such a system (I had to sweat my own way through it). If there is such a
guide (the Howto's I could find seem hopelessly outdated), could someone
please provide a pointer ? Otherwise, I would be glad to offer my experience
from this point on for a FAQ or (somwhat more up-to-date) mini-howto. Any
ideas ?

Greetings,

--
David Jander
Protonic Holland.


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Re: Support for MPC852T, any experience ?

[Wolfgang Denk]

Dear David,

in message <200306171314.50574.david.jander@protonic.nl> you wrote:
>
> Also on the DENX website I found their drivers for 8xx in the 2.4.4 kernel
> sources. Has anybody ported those drivers to a more recent version ?

Some / most of them are  available  in  our  linuxppc_2_4_devel  tree
(kernel version 2.4.20), too.

> from montavista. I have not been able to find an up to date guide for setting
> up such a system (I had to sweat my own way through it). If there is such a
> guide (the Howto's I could find seem hopelessly outdated), could someone
> please provide a pointer ? Otherwise, I would be glad to offer my experience

"Building Embedded Linux Systems" by Karim Yaghmour ? See
http://www.amazon.com/exec/obidos/tg/detail/-/059600222X/qid=1055849226/sr=8-1/ref=sr_8_1/103-3191409-0761469?v=glance&s=books&n=507846


Best regards,

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
Business is like a wheelbarrow. Nothing ever happens until you  start
pushing.

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Re: Support for MPC852T, any experience ?

[Frank Robbins]

Yes we have designed a board  Adder II  + the ppc-linux-kernel-2.4.21p7-1
kernel is in the development tree

What help do you need ?

You could just by the board it has every thing and is priced fairly
agreeable....?

Regards

Frank Robbins



Analogue & Micro Ltd,
9 Clytha Park Road
Newport
South Wales
NP20 4US
United Kingdom (Great Britain)
Email : Frank.Robbins@Analogue-Micro.com
Email : Frank@Analogue-Micro.com

http://www.Analogue-Micro.com

Tel: 44 (0)1633 666787
Fax: 44 (0)1633 666788

----- Original Message -----
From: "David Jander" <david.jander@protonic.nl>
To: <linuxppc-embedded@lists.linuxppc.org>
Sent: Tuesday, June 17, 2003 12:14 PM
Subject: Support for MPC852T, any experience ?


>
> Hi there,
>
> We are developing a board based on the MPC852T (fairly new model,
> stripped-down MPC866).
> Is there anybody who has sucessfully run linux-ppc on this processor yet
(or
> it's more advanced MPC866 cousin) ?
> Any experience ?
> I am specifically interested in using the SPI mode for SCC3 or 4, plus FEC
> with an LXT971A phy.
> I am new to this mailing list, but I have searched through its archive and
> came up with a (simple ?) SPI driver from Navin Bopurri.
> Also on the DENX website I found their drivers for 8xx in the 2.4.4 kernel
> sources. Has anybody ported those drivers to a more recent version ?
> I have now managed to set up a cross-development system comiling the
latest
> binutils, gcc-3.2.3 (--with-newlib) and the latest linuxppc_2_4_devel
kernel
> from montavista. I have not been able to find an up to date guide for
setting
> up such a system (I had to sweat my own way through it). If there is such
a
> guide (the Howto's I could find seem hopelessly outdated), could someone
> please provide a pointer ? Otherwise, I would be glad to offer my
experience
> from this point on for a FAQ or (somwhat more up-to-date) mini-howto. Any
> ideas ?
>
> Greetings,
>
> --
> David Jander
> Protonic Holland.
>
>
>


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Re: Support for MPC852T, any experience ?

[David Jander]

On Wednesday 18 June 2003 14:14, Frank Robbins wrote:
> Yes we have designed a board  Adder II  + the ppc-linux-kernel-2.4.21p7-1
> kernel is in the development tree

Great ! Have you had much trouble making all the hardware work, or do all the
existing drivers in arch/ppc/8xx_io work out of the box ?
We plan on using the FEC, SPI, SMC as RS232 port, SCC3 and SCC4 as aditional
RS232/485 serial ports or second ethernet depending on the aplication.
Equiped with a MMC slot (for MMC's in SPI mode over the SPI interface),
16-64Mb SDRAM, 2-8Mb Flash (for kernel, bootloader, some basic rootfs, data
storage) and the applications mostly on a fs on MMC.

> What help do you need ?

We are just starting development, and I was looking for some experience with
some or all of the elements I mention above. Some warnings about things to
avoid from the beginning, possible pitfalls, etc...
Right now we are in the middle of component choices and basic schematic design
of the CPU board.
I am specially interested in hearing about experience with using a filesystem
on a MMC via the SPI interface.

> You could just by the board it has every thing and is priced fairly
> agreeable....?

I looked at your web-page, and the little board looks quite interesting as a
testbed for starting software development and debugging before we actually
have some hadware, but we are not in such a hurry, and in the end we will
have our own hardware and the other board might just end up collecting dust
somewhere, and that would be a shame.... thank you for the offer anyway.

Greetings,

--
David Jander
Protonic Holland.


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Re: Support for MPC852T, any experience ?

[Wolfgang Denk]

Dear David,

in message <200306191106.39116.david.jander@protonic.nl> you wrote:
>
> Great ! Have you had much trouble making all the hardware work, or do all the
> existing drivers in arch/ppc/8xx_io work out of the box ?

They should work out of the box. This is just another member  of  the
8xx family.

> Equiped with a MMC slot (for MMC's in SPI mode over the SPI interface),

Are you sure you really want to do this? Please be aware that the SPI
port on the 8xx was NOT designed for high performance /  volume  data
transfers. Motorola writes:

        The SPI was not designed to be a high-bandwidth channel. It
        can run very quickly for bursts of up to 16-bits. But the
        peripheral has no FIFO and low priority in the MPC860 and
        thus you cannot burst lots of data quickly through the
        interface.
	...
        Note that the SPI is of lower priority internally than the
        SCCs, thus, the SPI will be the first device to be "starved".
        Snce it has no FIFO, it is especially sensitive to underruns.
        The best way to prevent this is to use a buffer size of 1
        "character" (of size programmed in the mode register).
        ...

Also, you should be aware that the SPI  protocol  is  implemented  as
microcode  running  on the CPM, so any high-speed data transfers will
suck up CPM performance.


>From my experience SPI on the 8xx should NOT be used  for  mass  data
transfers. You will run into a LOT of problems. Been there ...


> 16-64Mb SDRAM, 2-8Mb Flash (for kernel, bootloader, some basic rootfs, data
> storage) and the applications mostly on a fs on MMC.

You mean a filesystem on a device over SPI? I _strongly_ recommend to
change your design. You will run into _serious_ trouble that way.


> I am specially interested in hearing about experience with using a filesystem
> on a MMC via the SPI interface.

See above. Don't even think about it.




Best regards,

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
Another megabytes the dust.

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