MAC Address changes on reboot

I've noticed that each time I reboot or power cycle the SoC, it appears to have a different MAC address. I thought that the MAC address should be fixed for a device and was not reprogrammable. On further investigation, it appears the EMAC register map has 128 MAC address registers. Does linux build use these? Is there actually a hard coded address in the MAC or does it require an external MAC address EEPROM to read from?

I'm using yocto project linux version 3.9.0, is there a known issue with reading the MAC address? Or is the MAC address supposed to be programmed by software each boot-up?