On Oct 18, 2005, at 12:08 PM, Jason Thorpe wrote:

>
> On Oct 18, 2005, at 10:46 AM, Jesse Off wrote:
>
>> I wrote the epe driver for the TS-7200 board.  This board has the  
>> MAC set by the RedBoot firmware and IIRC, I just leave the value  
>> untouched.  Just keep in mind if you overwrite the MAC using some  
>> method specific to your board, it will break the TS-7200 unless  
>> you make sure it happens only for your board.
>
> There is a better way to do this using properties.  I'll follow-up  
> more later.

...and now the follow-up.. sorry for the delay.

Take a look at sys/arch/evbppc/walnut/autoconf.c -- in particular,  
the device_register() function:

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         if (strcmp(dev->dv_cfdata->cf_name, "emac") == 0 &&
             strcmp(parent->dv_cfdata->cf_name, "opb") == 0) {
                 /* Set the mac-addr of the on-chip Ethernet. */
                 /* XXX 405GP only has one; what about CPUs with two? */
                 if (prop_set(dev_propdb, dev, "mac-addr",
                              &board_data.mac_address_local,
                              sizeof(board_data.mac_address_local),
                              PROP_CONST, 0) != 0)
                         printf("WARNING: unable to set mac-addr "
                             "property for %s\n", dev->dv_xname);
                 return;
         }

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	.

...and now look at arch/powerpc/ibm4xx/dev/if_emac.c's emac_attach():

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	.
	.

         /* Fetch the Ethernet address. */
         if (prop_get(dev_propdb, &sc->sc_dev, "mac-addr", enaddr,
                      sizeof(enaddr), NULL) != sizeof(enaddr)) {
                 printf("%s: unable to get mac-addr property\n",
                     sc->sc_dev.dv_xname);
                 return;
         }

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	.
	.

The dev_propdb property database is created in MI code (configure()  
in subr_autoconf.c).

I think this represents a good way to handle board-specific ways of  
fetching certain kinds of information for SOC devices for embedded  
systems.

-- thorpej