A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?
Please read http://www.netmeister.org/news/learn2quote.html
In message 003c01c6cd9c$aa064e10$091a1bac@serra.es you wrote:
No, you must erase the flash region where the MAC address is stored.
...
Can u-boot allow me to change HW MAC address?
Your reply does not answer the OP's question and is incomplete or wrong.
The OP asked about the hardware MAC address, but you are probably talking about the "ethaddr" environment variable, which is a very different thing.
Also, if the "ethaddr" is write protected or not depends on your board configuration.
Best regards,
Wolfgang Denk