Bear in mind that I have not tried or tested this, but here is a sample pfi.conf file from the server. It just shows available options and such:
#######################################################################
# $Id: pfi.conf,v 1.10 2005/07/09 00:07:07 cpressey Exp $
# Defaults for pfi.conf.
# A space-separated list of what services to restart when we are done
# changing options. The services are the base names of RCNG scripts
# (i.e. without the "/etc/rc.d/" prefix.) Note that these must be
# given explicitly in the same order they would normally be started
# by rcorder during RCNG (e.g. "netif dhclient sshd"); they are not
# automatically ordered by their dependencies here.
pfi_rc_actions=""
# Determines which installer frontend to use. Defaults to "curses";
# other legal options are "cgi" and "none".
pfi_frontend="curses"
# Determines which installer backend to use. The standard backend
# is now the Lua backend, but this can be changed, to start an
# alternate backend. (See example #4, below.)
pfi_backend="/usr/local/bin/lua50c51 /usr/local/share/dfuibe_lua/main.lua"
pfi_backend="$pfi_backend option.booted_from_install_media=true"
# When using the curses frontend:
# Set the amount of time, in milliseconds, which must pass after
# the 'ESC' key is pressed, in order for it to be recognized
# as a plain 'ESC' keystroke, and not part of an escape code.
pfi_curses_escdelay="150"
# A password to set as the root password on the LiveCD, if any.
pfi_set_root_password=""
# Control corresponding sshd options. To make sure sshd restarts with
# these options, add "sshd" to pfi_rc_actions.
pfi_sshd_permit_root_login="NO"
pfi_sshd_permit_empty_passwords="NO"
# An script to run before the installer. It is assumed this script is
# located on the pfi media. While it is run, the media's root directory
# is mounted on /mnt.
pfi_script=""
# A program to run before the installer. It is assumed to reside on
# the LiveCD; /mnt is not mounted.
pfi_run=""
# What transport layer the DFUI in the installer should use. Valid
# values are currently "caps", "npipe", and "tcp".
pfi_dfui_transport="tcp"
# User to automatically log in as, or "NONE".
pfi_autologin="NONE"
# Command to use to reboot. "shutdown -h now" is typically used
# interactively, to give the user a chance to eject the disk, but
# "shutdown -r now" can be used for headless operation.
pfi_shutdown_command="shutdown -h now"
#######################################################################
# EXAMPLES
# To use one of these examples, extract it to a text file and remove the
# leading pound-signs. Copy this text file to the file "/pfi.conf"
# on a floppy disk or USB pen drive (hereinafter referred to as "the pfi
# media") and have that media inserted or attached to the computer while
# you boot from the installer CD-ROM. The installer will attempt to
# locate this file and, if found, will use the variables present within it
# to configure the installer boot process.
# This file has the same syntax as /etc/rc.conf, and it can contain any
# setting which is meaningful in /etc/rc.conf as well. Any rc.conf
# setting which is given will only be obeyed, however, if the RCNG script
# to which that setting applies is named in pfi_rc_actions.
# EXAMPLE 1:
# Boot the installer headless, configure the network interface dc0,
# and start the CGI frontend.
#
# ifconfig_dc0="DHCP"
# pfi_rc_actions="netif dhclient"
# pfi_frontend="cgi"
# pfi_autologin="installer"
# pfi_shutdown_command="shutdown -r now"
# EXAMPLE 2:
# Boot the installer headless, configure the network interface rl0,
# and allow ssh'ing into the box as root with the password "sekrit".
#
# ifconfig_rl0="DHCP"
# pfi_sshd_permit_root_login="YES"
# pfi_set_root_password="sekrit"
# pfi_rc_actions="netif dhclient sshd"
# pfi_frontend="none"
# pfi_autologin="installer"
# pfi_shutdown_command="shutdown -r now"
# EXAMPLE 3:
# Boot the cd and setup a PXE/TFTP/DCHPD server environment
# so that clients can boot from the network and enter the installer
#
# Enable tftp and NFS services with pxeboot and a kernel available via
# tftp and the CD's root mount available via NFS.
#
# pfi_boot_tftp_server="YES"
# pfi_boot_nfs_server="YES"
# pfi_boot_pxeserver="YES"
# pfi_boot_ipserver="YES"
# pfi_option_subnet-mask="255.255.255.0"
# pfi_option_routers="10.0.250.1"
# pfi_filename="pxeboot"
# pfi_ddns-update-style="none"
# pfi_option_domain-name="domain.com"
# pfi_option_broadcast-address="10.0.250.255"
# pfi_option_domain-name-servers="192.168.64.3"
# pfi_server-name="DHCPServer"
# pfi_server-identifier="10.0.250.50"
# pfi_default-lease-time="7200"
# pfi_max-lease-time="7200"
# pfi_subnet="10.0.250.0 netmask 255.255.255.0"
# pfi_next-server="10.0.250.50"
# pfi_range="10.0.250.29 10.0.250.250"
# EXAMPLE 4:
# Revert to the traditional, C language backend.
#
# pfi_backend="/usr/local/sbin/dfuibe_installer"