Re: Can software discover MPC8xx variant?

Ok, but in this case the hardware itself wouldn't know waht revision or
whatever it is. And they already have to change the processor, so you have to
change the hardware anyway, mount or not a few resistors shouldn't be hard.

On Wednesday 29 January 2003 15:02, you wrote:

Or you could set it in some type of data structure in your bootloader.  No
hardware change this way.

-----Original Message-----
From: Leonardo Pereira Santos [mailto:lsantos@pd3.com.br]
Sent: Wednesday, January 29, 2003 11:30 AM
To: linuxppc-embedded@lists.linuxppc.org
Subject: Re: Can software discover MPC8xx variant?




As the 8xx family is supported by the kernel, I assume that what you want
is to know if the 8xx processor running supports some feature? If this is
the case, I can tell you how to do it the way I'd.
You can define some ioport with pull-up and pool-down resistors and in the
manufacturing process specifiy if this board is for product A, then you
should use MPC850DSL and you will mount some of the pull-ups and
pull-downs. If the board is for product B, then you should mount MPC850SAR
and mount differently the pull-ups and downs. By reading the value on the
selected pins, you might de able to know what board this is. This scheme
can also be used to know what hardware revision your board have.

On Wednesday 29 January 2003 12:13, Marius Groeger wrote:

quoted

On Wed, 29 Jan 2003, Alex Zeffertt wrote:

quoted

Can anybody tell me if there is a way to identify which processor from
the MPC8xx family software is running on.  I hoped I could use the IMMR
special purpose register.  However, this only tells you the silicon
revision, which can have the same value even if the processors are
different!

Does the processor type (e.g. 862, 857T, 857DSL) reside anywhere in the
processor?

U-Boot/PPCboots cpu/mpc8xx/cpu.c contains a lot of generic type
detection code, but even there the assumes that the basic type is
known at compile time.

Regards,
Marius

---------------------------------------------------------------------------

quoted

-- Marius Groeger           SYSGO Real-Time Solutions AG
mgroeger@sysgo.de Software Engineering     Embedded and Real-Time
Software www.sysgo.de Voice: +49-6136-9948-0   Am Pfaffenstein 14
www.osek.de FAX:   +49-6136-9948-10  55270 Klein-Winternheim, Germany
www.elinos.com

- --

Leonardo Pereira Santos
Engenheiro de Projetos
PD3 Tecnologia
av. Pará 330/202
(51) 3337 1237

Today Fortune tells us:
Are you scared of speed? If so, try Windows NT.

- --

Leonardo Pereira Santos
Engenheiro de Projetos
PD3 Tecnologia
av. Pará 330/202
(51) 3337 1237

Today Fortune tells us:
Is knowledge knowable?  If not, how do we know that?


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