[U-Boot] ethernet: ROM MAC address vs env variable MAC address
Lukasz Majewski
lukma at denx.de
Thu Nov 9 10:14:24 UTC 2017
Hi Prabhakar,
> Hi All,
>
> I am seeing following type of code for MAC address write for a
> network device.
>
> net/eth-uclass.c eth_post_probe() or net/eth_legacy.c
> eth_write_hwaddr()
>
> eth_env_get_enetaddr_by_index("eth", dev->seq, env_enetaddr);
> if (!is_zero_ethaddr(env_enetaddr)) {
> if (!is_zero_ethaddr(pdata->enetaddr) &&
> memcmp(pdata->enetaddr, env_enetaddr, ARP_HLEN)) {
> printf("\nWarning: %s MAC addresses don't
> match:\n", dev->name);
> printf("Address in ROM is %pM\n",
> pdata->enetaddr);
> printf("Address in environment is %pM\n",
> env_enetaddr);
> }
>
> /* Override the ROM MAC address */
> memcpy(pdata->enetaddr, env_enetaddr, ARP_HLEN);
>
> Why ROM MAC address getting overwritten by environment env MAC
> address. MAC address is something unique and assigned to a particular
> device. So one should never change its MAC address.
>
It may happen that company which uses NXP processor wants to use their
own set of MAC addresses.
> Please suggest.
>
> Regards,
> Prabhakar
>
> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> https://lists.denx.de/listinfo/u-boot
Best regards,
Lukasz Majewski
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