#!/bin/sh -e

PATH="/usr/sbin:/usr/bin:/sbin:/bin"

UDEVSTART=/sbin/udevstart

# default maximum size of the /dev ramfs
ramfs_size="1M"

[ -x $UDEVSTART ] || exit 0

. /etc/udev/udev.conf

case "$(uname -r)" in
  2.[012345].*)
    echo "udev requires a kernel >= 2.6, not started."
    exit 0
    ;;
esac

if ! grep -q '[[:space:]]ramfs$' /proc/filesystems; then
    echo "udev requires ramfs support, not started."
    exit 0
fi

if [ ! -e /proc/sys/kernel/hotplug ]; then
    echo "udev requires hotplug support, not started."
    exit 0
fi

##############################################################################

# we need to unmount /dev/pts/ and remount it later over the ramfs
unmount_devpts() {
  if mountpoint -q /dev/pts/; then
    umount -l /dev/pts/
  fi

  if mountpoint -q /dev/shm/; then
    umount -l /dev/shm/
  fi
}

# mount a ramfs over /dev, if somebody did not already do it
mount_ramfs() {
  if grep -E -q "^[^[:space:]]+ /dev ramfs" /proc/mounts; then
    return 0
  fi

  # /.dev is used by /sbin/MAKEDEV to access the real /dev directory.
  # if you don't like this, remove /.dev/.
  [ -d /.dev ] && mount --bind /dev /.dev

  echo -n "Mounting a ramfs over /dev..."
  mount -n -o size=$ramfs_size,mode=0755 -t ramfs none /dev
  echo "done."
}

# I hate this hack.  -- Md
make_extra_nodes() {
  grep '^[^#]' /etc/udev/links.conf | \
  while read type name arg1; do
    [ "$type" -a "$name" -a ! -e "/dev/$name" -a ! -L "/dev/$name" ] ||continue
    case "$type" in
    L)
      ln -s $arg1 /dev/$name
      ;;
    D)
      mkdir -p /dev/$name
      ;;
    M)
      mknod --mode=600 /dev/$name $arg1
      ;;
    *)
      echo "unparseable line ($type $name $arg1)"
      ;;
    esac
  done
}

##############################################################################

if [ "$udev_root" != "/dev/" ]; then
  echo "WARNING: udev_root != /dev/"

case "$1" in
  start)
    if [ -e "$udev_root/.udev.tdb" ]; then
      if mountpoint -q /dev/; then
        echo "FATAL: udev is already active on $udev_root."
        exit 1
      else
        echo "WARNING: .udev.tdb already exists on the old $udev_root!"
      fi
    fi
    mount -n -o size=$ramfs_size,mode=0755 -t ramfs none $udev_root
    echo -n "Creating initial device nodes..."
    $UDEVSTART
    echo "done."
    ;;
  stop)
    start-stop-daemon -K -x /sbin/udevd 
    echo -n "Unmounting $udev_root..."
    # unmounting with -l should never fail
    if umount -l $udev_root; then
      echo "done."
    else
      echo "failed."
    fi
    ;;
  restart|force-reload)
    $0 stop
    $0 start
    ;;
  *)
    echo "Usage: /etc/init.d/udev {start|stop|restart|force-reload}"
    exit 1
    ;;
esac

  exit 0
fi # udev_root != /dev/

##############################################################################
# When modifying this script, do not forget that between the time that
# the new /dev has been mounted and udevstart has been run there will be
# no /dev/null. This also means that you cannot use the "&" shell command.

case "$1" in
  start)
    if [ -e "$udev_root/.udev.tdb" ]; then
      if mountpoint -q /dev/; then
        echo "FATAL: udev is already active on $udev_root."
        exit 1
      else
        echo "WARNING: .udev.tdb already exists on the old $udev_root!"
      fi
    fi
    unmount_devpts
    mount_ramfs
    ACTION=add
    echo -n "Creating initial device nodes..."
    $UDEVSTART
    make_extra_nodes
    echo "done."
#    /etc/init.d/mountvirtfs start
    ;;
  stop)
    start-stop-daemon -K -x /sbin/udevd 
    unmount_devpts
    echo -n "Unmounting /dev..."
    # unmounting with -l should never fail
    if umount -l /dev; then
      echo "done."
      umount -l /.dev || true
#      /etc/init.d/mountvirtfs start
    else
      echo "failed."
    fi
    ;;
  restart|force-reload)
    start-stop-daemon -K -x /sbin/udevd 
    echo -n "Recreating device nodes..."
    ACTION=add
    $UDEVSTART
    make_extra_nodes
    echo "done."
    ;;
  *)
    echo "Usage: /etc/init.d/udev {start|stop|restart|force-reload}"
    exit 1
    ;;
esac

exit 0