# uname -a

# ls -l /boot/kernel/kernel

# kldstat

# kldload snd_driver

# cat /dev/sndstat

# fetch http://val.bmstu.ru/unix/Media/bird_1.au

# cp bird_1.au /dev/audio0.0
или
# cp bird_1.au /dev/dsp0.0

# cat /boot/loader.conf

snd_ich_load="YES"

# kldload ipfw

# sysctl net.inet.ip.fw.enable=0

# sysctl net.inet.ip.ttl=2

# cat /etc/sysctl.conf

# cat /boot/loader.conf

hint.acpi.0.disabled="1"

http://www.freebsd.org/doc/ru/books/handbook/kernelconfig-building.html