[U-Boot] setting Ethernet address

[Benedict Hewson <benedict@hewson-venieri.com>]

I am trying to get network support working on the Embest imx6 Marsboard.
I have been reading through the various imx6 boards and it appears that some 
at least store a MAC address in the fuse memory. 

This does not appear to be set on the MarSboard - the fuse memory contains 0.
The original 2009 version used the ethaddr environment variable.
If I try to include this in the config header file either as part of the 
CONFIG_EXTRA_ENV_SETTINGS - 

#define CONFIG_ETHADDR 00:01:02:03:04:05

#define	CONFIG_EXTRA_ENV_SETTINGS \
"ethaddr="__stringify(CONFIG_ETHADDR)"\0" \

or more simply as in the original version

"ethaddr=00:01:02:03:04:05\0" \

everything compiles, but when booting I get "Warning: failed to set MAC 
address"  and when listing the environment variables ethhaddr is missing.
If I manually set ethaddr and ipaddr the networking seems to work as I can 
ping the board successfully.

I assume I am missing something somewhere and I expect if I go through the 
source I will eventually find it, but it is probably going to be quicker to 
ask.


many thanks
Ben