initramfs_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

#Function for parsing command line options with "=" in them
# get_opt("init=/sbin/init") will return "/sbin/init"
get_opt() {
        echo "$@" | cut -d "=" -f 2
}

#Defaults
init="/sbin/init"
root="/dev/hda1"

#Process command line options
for i in $(cat /proc/cmdline); do
        case $i in
                root\=*)
                        root=$(get_opt $i)
                        ;;
                init\=*)
                        init=$(get_opt $i)
                        ;;
        esac
done

#Mount the root device
mount "${root}" /newroot

#Check if $init exists and is executable
if [[ -x "/newroot/${init}" ]] ; then
        #Unmount all other mounts so that the ram used by
        #the initramfs can be cleared after switch_root
        umount /sys /proc

        #Switch to the new root and execute init
        exec switch_root /newroot "${init}"
fi

#This will only be run if the exec above failed
echo "Failed to switch_root, dropping to a shell"
exec sh