#!/bin/sh

 mount -v -n -t proc  -onodev,noexec,nosuid proc  /proc
 mount -v -n -t sysfs -onodev,noexec,nosuid sysfs /sys

 mount -v -t ext4 /dev/sdb1 /mnt/root

 mount --move /dev  /mnt/root/dev/
 mount --move /proc /mnt/root/proc/
 mount --move /sys  /mnt/root/sys/

 echo "Switching root filesystem..."
 cd /mnt/root
 pivot_root . mnt/tmp/

 exec chroot . /sbin/init