Boot the Ubuntu live CD and quit the installer. Ensure that Ubuntu has a working Internet connection, then enable the "universe" package repository by uncommenting the corresponding lines in /etc/apt/sources.list. Now open a terminal and run the following commands to install prerequisite packages:

$ sudo -s
# apt-get update
# apt-get install dhcp3-server tftpd xinetd cu

Run this command to configure a static address on the PC's Ethernet interface:

# ifconfig eth0 up 192.168.2.1 netmask 255.255.255.0

I've found you may also need to configure the static address on your Ethernet adapter in the "Network Connections" dialog (under Preferences in the System menu) to prevent Network Manager from getting in the way. Yes, this is a little hackish, but we only need it to work for the duration of the install...

Now enable routing and configure a simple NAT using iptables so that the ALIX board can access the Internet through your PC's wireless connection:

# echo 1 > /proc/sys/net/ipv4/ip_forward
# iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE
# iptables -A FORWARD -i eth0 -j ACCEPT
# iptables -A FORWARD -i wlan0 -m state --state RELATED,ESTABLISHED -j ACCEPT

Replace /etc/dhcp3/dhcpd.conf with the following:

authoritative;

shared-network LOCAL-NET {
  option domain-name-servers 8.8.8.8;

  subnet 192.168.2.0 netmask 255.255.255.0 {
    option routers 192.168.2.1;
    filename "pxeboot";
    range 192.168.2.100 192.168.2.200;
    default-lease-time 600;
    max-lease-time 7200;
  }
}

Also, edit the file /etc/default/dhcp3-server so that its last line reads:

INTERFACES="eth0"

Now you can start the DHCP server.

# /etc/init.d/dhcp3-server start

Create an xinetd file at /etc/xinetd.d/tftp with:

service tftp
{
  socket_type = dgram
  protocol = udp
  wait = yes
  user = root
  server = /usr/sbin/in.tftpd
  server_args = -s /tftpboot
}

Next create the aforementioned directory /tftpboot. Download the files bsd.rd and pxeboot from the /4.8/i386/ directory on your favorite OpenBSD mirror and copy them here. Then, restart xinetd to load the new configuration:

# /etc/init.d/xinetd restart

Connect your laptop's serial port (or plugged-in USB-serial adapter) to the ALIX board's serial port with your null modem cable, then use the cu command to open the serial console. For example, if you're using a USB adapter:

# cu -e -o -s 115200 -l /dev/ttyUSB0

When the OpenBSD ramdisk boots, you will be prompted with the choices: (I)nstall, (U)pgrade, or (S)hell? – press the I key to begin the installer. Therein you will be asked a few preliminary questions.

Next you will need to set up your disk partitions and slices. In fdisk(8), specify that you want to use the whole disk for OpenBSD. Then you will be brought to the BSD disk label editor.

Press P to view the disk's current BSD slices; you shouldn't see anything here except the "c" slice, which represents the entire disk. Use the A command to create the disk slice set shown in Table 3.1, “OpenBSD disk slices”.

When that is done, press Q to quit the label editor, then press Y to confirm that you wish to write the new disk label. Confirm your way past any relevant warning messages, and the CF card will be partitioned and formatted for OpenBSD's installation.

Next you will be asked where to find the OpenBSD installation sets: choose the default mechanism, http, and use the default OpenBSD mirror (or any other mirror of your choice). Make any desired changes to the default set selection and then proceed to the next stage of the installer.^[4]

Once the sets have been installed, you can shut down your Ubuntu PXE boot server and reboot the ALIX board into its new OpenBSD installation. You may also wish to disable PXE booting in the ALIX's BIOS while you are not using it.