# pciconf -vl is useful as well.
Between
# kldstat -v (to show the drivers currently compiled into the kernel and the kernel modules loaded),
# pciconf -vl (to show the PCI devices/buses detected and drivers attached),
# usbdevs to list the USB devices/buses) you should be able to figure out what drivers need to be in the kernel.
When experimenting with new kernels,
nextboot() and
KODIR come in handy. When installing the new kernel, add
KODIR=/boot/kernel.something. That will install the kernel into the /boot/kernel.something directory, and not overwrite the known-to-work /boot/kernel. Then, use
nextboot -k kernel.something to tell the loader which kernel to use on the next boot. If that boot fails, rebooting will load /boot/kernel again.
Using KODIR and nextboot makes testing kernels so much simpler and fool-proof, as you can always just reboot to get back to a working system.
