You do not need devfs - the classic way to do things is to make device special files in /dev by hand (read warning below though)
To use devfs, be sure to configure your kernel properly before compiling.
To make device nodes, use mknod.
mknod name type major minor
name: name of device file, like hda2
type: 'c' for character devices, 'b' for block device (no quotes around 'c' or 'b')
major, minor: device numbers
A list of device numbers can be found at http://www.kernel.org/pub/linux/docs...t/devices.txt,
or in your kernel source. You do not need to make all devices, just the ones you use.
Warning: if you want to keep using devfs, which is a virtual filesystem containing the relevant special files, you can not place special files in /dev.