Bare bones Busybox /init (adapted from http://jootamam.net/howto-initramfs-image.htm)

init

#!/bin/sh

# Mount things needed by this script
mount -t proc proc /proc
mount -t sysfs sysfs /sys

# Disable kernel messages from popping onto the screen
echo 0 > /proc/sys/kernel/printk

# Clear the screen
clear

# Create all the symlinks to /bin/busybox
busybox --install -s

# Create device nodes
mknod /dev/null c 1 3
mknod /dev/tty c 5 0
mdev -s