Ethernet MAC address
If, for any reasons, you want to change your board Ethernet MAC address, here is the procedure.
Armadeus APF9328 board has a separate MAC controller, the DM9000 chip from Davicom . The APF schematic, page 10, shows the implementation of the chip with an EEPROM chip to store its parameters, including MAC address.
U-boot has a parameter containing the Ethernet address. This parameter is independent from the hardware address. The parameter is ethaddr.
BIOS> printenv ethaddr 00:1E:AC:XX:XX:XX
XX:XX:XX being the board specific address.
Change MAC address
It can happen that the MAC address is wrong (e.g.: 00:00:0E:00:00:00 in my case), empty or that you want to change it.
Empty MAC address
If the board MAC address is empty, the procedure is simplified.
In U-boot, simply set the correct value in the parameter ethaddr, ping any address and save the environment.
BIOS> setenv ethaddr 00:1e:ac:XX:XX:XX BIOS> ping 1 MAC: 00:1e:ac:XX:XX:XX operating at 100M full duplex mode [Ctrl-C] Abort ping failed; host 1 is not alive BIOS> saveenv
FIXME: The above message are made-up, don't know if reprogramming message is displayed or not...
Wrong MAC address
If the MAC address is already set but wrong, changing the U-boot parameter ethaddr will not automatically reprogram the EEPROM. It is necessary to indicate to U-boot to reprogram the EEPROM.
This is made possible by a specific patch to U-boot by Armadeus for the DM9000 chip  line 68 and following. Thanks to this patch, setting the ethaddr parameter to ff:ff:ff:ff:ff:ff and ping any IP will provoke the MAC address reprogramming. Then simply set ethaddr parameter again to the correct MAC address and ping any IP address, as shown below.
BIOS> setenv ethaddr ff:ff:ff:ff:ff:ff BIOS> ping 1 Warning: MAC addresses reprogramming.. MAC: ff:ff:ff:ff:ff:ff operating at 100M full duplex mode [Ctrl-C] Abort ping failed; host 1 is not alive BIOS> setenv ethaddr 00:1e:ac:XX:XX:XX BIOS> ping 1 Warning: MAC addresses reprogramming.. MAC: 00:1e:ac:XX:XX:XX operating at 100M full duplex mode [Ctrl-C] Abort ping failed; host 1 is not alive BIOS>
Check your MAC address in Linux
Linux kernel and U-boot do not use the same source to get the board MAC address. As mentioned before, U-boot trusts its parameter ethaddr. Instead, Linux kernel, which uses the DM9000 driver, reads the MAC address from the EEPROM. During Linux boot, the driver prints the MAC address.
[...] dm9000 Ethernet Driver, V1.31 eth0: dm9000e at c1854000,c1856002 IRQ 110 MAC: 00:1e:ac:xx:xx:xx (eeprom) [...]
When logged on Linux, the tool ifconfig also displays information about the Ethernet MAC address.
# ifconfig eth0 eth0 Link encap:Ethernet HWaddr 00:1E:AC:XX:XX:XX inet addr:192.168.0.10 Bcast:192.168.0.255 Mask:255.255.255.0 inet6 addr: fe80::21e:acxx:xxxx:xx/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:6 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:468 (468.0 B) Interrupt:110 Base address:0x4000
The field HWaddr corresponds to the MAC address read by dm9000 driver and used during communication.