Linux/AM3352: Change MAC address

Hi,

Mac address is setup in the u-boot. In general the MAC address is programmed in the EFUSE registers during SoC production and u-boot code reads this address (unique for each device) and sets it as eth_addr.

If you wish to override this you have two options:
1. Program the mac address in external EEPROM and read from there.
2. Set the MAC addres in a static structure (or array) in u-boot and use it as mac address.

The code that deals with setting up the MAC is located in u-boot/board/ti/am335x/board.c:

#if !defined(CONFIG_SPL_BUILD)
/* try reading mac address from efuse */
mac_lo = readl(&cdev->macid0l);
mac_hi = readl(&cdev->macid0h);
mac_addr[0] = mac_hi & 0xFF;
mac_addr[1] = (mac_hi & 0xFF00) >> 8;
mac_addr[2] = (mac_hi & 0xFF0000) >> 16;
mac_addr[3] = (mac_hi & 0xFF000000) >> 24;
mac_addr[4] = mac_lo & 0xFF;
mac_addr[5] = (mac_lo & 0xFF00) >> 8;

if (!env_get("ethaddr")) {
printf("<ethaddr> not set. Validating first E-fuse MAC\n");

if (is_valid_ethaddr(mac_addr))
eth_env_set_enetaddr("ethaddr", mac_addr);
}

mac_lo = readl(&cdev->macid1l);
mac_hi = readl(&cdev->macid1h);
mac_addr[0] = mac_hi & 0xFF;
mac_addr[1] = (mac_hi & 0xFF00) >> 8;
mac_addr[2] = (mac_hi & 0xFF0000) >> 16;
mac_addr[3] = (mac_hi & 0xFF000000) >> 24;
mac_addr[4] = mac_lo & 0xFF;
mac_addr[5] = (mac_lo & 0xFF00) >> 8;

if (!env_get("eth1addr")) {
if (is_valid_ethaddr(mac_addr))
eth_env_set_enetaddr("eth1addr", mac_addr);
}

env_set("ice_mii", prueth_is_mii ? "mii" : "rmii");
#endif

Best Regards,
Yordan