Introduction

At the early stages of product development there is often not enough prototype product hardware to go around. One of the wonderful things about using embedded Linux is many people can access the device at the same time.

In my office I use a Linux firewall running dnsmasq and iptables. To allow others to access the prototype product hardware I give the device a fixed MAC address in uboot, assigned a fixed IP address to that MAC address, and punch a hole in the firewall to allow incoming telnet connections using NAT.

Fixed Ethernet MAC address in uboot

I added ethaddr to the uboot environment variable in both the attached_board and sd_card installer default uboot environment file.

echo "ethaddr=00:04:a3:2e:18:15" >> $DEVDIR/installer/u-boot-installer/methods/attached_board/installer_uEnv.txt
echo "ethaddr=00:04:a3:2e:18:15" >> $DEVDIR/installer/u-boot-installer/methods/sd_card/installer_uEnv.txt

Fixed IP via dnsmasq configuration

On your DHPC server (if using dnsmasq), do something like

echo "dhcp-host=00:04:a3:2e:18:15,bb,         10.111.0.33,infinite" | sudo tee -a /etc/dnsmasq.conf
sudo service dnsmasq restart