Mac address Home Media
From NAS-Central Iomega Wiki
The mac address of the Home Media is stored on harddisk. It is provided when loading the gmac kernel module.
Contents of /etc/modules:
gmac mac_adr=0x00,0xD0,0xB8,0x12,0x34,0x56 thermAndFan ehci-hcd usb-storage usblp
On a factory reset the MAC address is removed from /etc/modules. Then /etc/init.d/gmac will extract the address from one of the 2 u-boot environment blocks, and write it to /etc/modules:
unset ethaddr
for blk in 239 10846 ; do
eval `dd if=/dev/sda skip=${blk} count=16 2> /dev/null \
| readenv | grep ethaddr`
if [ -n "${ethaddr}" -a "${ethaddr}" != "${mfgMAC}" ] ; then
break
fi
done
if [ -z "${ethaddr}" -o "${ethaddr}" = "${mfgMAC}" ] ; then
echo
echo "FATAL: $0 found invalid (or no) MAC ${ethaddr} in /etc/modules"
echo "or u-boot env blocks at 239 or 10846 - going catatonic ..."
mcucmd led_err
mcucmd gauge_critical
sh ## stop mfg boot dead at a shell prompt
fi
if lsmod | grep ^gmac ; then
/bin/ip link set eth0 address "${ethaddr}"
else
modarg=0x$(echo ${ethaddr} | sed -e 's/:/,0x/g')
sed -i -e "s/^gmac.*/gmac mac_adr=${modarg}/" /etc/modules
fi
exit 0
The MAC addresses in the environment blocks could be found at absolute byte offsets 122380 and 5553164 on harddisk. (No guarantee about that addresses. Don't know how the environment blocks are filled in the factory.)
