[U-Boot] [PATCH 05/15] powerpc/83xx/km: add MV88E6122 switch support for kmvect1

[Kim Phillips]

On Fri, 18 Jan 2013 10:14:39 +0100
Holger Brunck <holger.brunck at keymile.com> wrote:

> On 01/18/2013 01:44 AM, Kim Phillips wrote:
> > On Thu, 17 Jan 2013 13:47:51 +0100
> > Holger Brunck <holger.brunck at keymile.com> wrote:
> > 
> >> +	if (piggy_present()) {
> >> +		uchar enetaddr[6];
> >> +		if (eth_getenv_enetaddr("ethaddr", enetaddr)) {
> >> +			/* increment last 3 bytes */
> >> +			u32 val = (enetaddr[3] << 16) + (enetaddr[4] << 8)
> >> +				+ enetaddr[5];
> >> +			val++;
> >> +			enetaddr[3] = (val >> 16) & 0xFF;
> >> +			enetaddr[4] = (val >>  8) & 0xFF;
> >> +			enetaddr[5] = (val >>  0) & 0xFF;
> >> +			if (!eth_setenv_enetaddr("eth1addr", enetaddr)) {
> >> +				setenv("ethact", "UEC2");
> >> +				setenv("netdev", "eth1");
> >> +				puts("using PIGGY for network boot\n");
> >> +			} else
> >> +				puts("using frontport for network boot\n");
> >> +		}
> >> +	} else
> >> +		puts("using frontport for network boot\n");
> >> +#endif
> >> +
> > 
> > AFAIK, assigning the switch MAC address to the front port's MAC
> > address plus one isn't acceptable practice for u-boot board code.
> > Get eth1addr in the same manner ethaddr is obtained/assigned.
> 
> Because you may get a MAC adress which is already given to someone else? In our
> case this can't happen. We reserve for one instance of this board exactly two
> MAC adresses. The first one is read out at startup from the inventory in
> keymile/common/ivm.c. The second one is calculated like above. But it is a
> unique MAC adress, because exactly this MAC adress is reserved for this board.

it can happen if if setting ethaddr from eeprom somehow fails, and/or
the user manually modifies ethaddr in the environment.

> But maybe we should move the code to the location where we set ethaddr,

yes, indeed

> even if the calculation would be the same?

ideally ethaddr and eth1addr would be stored as separate entities in
the eeprom.

Kim