function fullpath() {
  local f=$1
  if [ "${f#/}" = "$f" ]; then
    echo `pwd`/"$f"
  else
    echo "$f"
  fi
}

function cleanup () {
  rm -rf "$TMP_BUILD_DIR"
}

function ensure_binaries() {
  BINARY_DEPS="${BUSYBOX}"
  for _FLVR in ${RAMDISK_ELEMENT} ; do
    _FILE="${ELEMENTS_DIR}/${_FLVR}/binary-deps"
    if [ -a $_FILE ]; then
      for _LINE in $(cat $_FILE) ; do
        BINARY_DEPS="${BINARY_DEPS} $_LINE"
      done
    fi  
  done

  for _BIN in $BINARY_DEPS ; do
    _LOCATION=""
    _LOCATION="${_LOCATION:-$(which $_BIN)}"
    if [ -z "$_LOCATION" ]; then
      echo "$_BIN is not found in your PATH" 1>&2
      echo "Please install it on your system"
      exit 1
    fi
  done

  export BINARY_DEPS
}

function create_base () {
  echo "Creating base system"

  mkdir -p "$TMP_MOUNT_PATH/bin"
  ln -s bin "$TMP_MOUNT_PATH/sbin"
  mkdir -p "$TMP_MOUNT_PATH/lib"
  ln -s lib "$TMP_MOUNT_PATH/lib64"
  mkdir -p "$TMP_MOUNT_PATH/lib/modules"
  mkdir -p "$TMP_MOUNT_PATH/etc"
  mkdir -p "$TMP_MOUNT_PATH/etc/udev"
  # cjk adding for discovery support
  mkdir -p "$TMP_MOUNT_PATH/var/lib/dhcp"
  mkdir -p "$TMP_MOUNT_PATH/var/run"

  mkdir -p "$TMP_MOUNT_PATH/lib/udev/rules.d"
  cp -a "$LIB_UDEV/rules.d/50-firmware.rules" "$TMP_MOUNT_PATH/lib/udev/rules.d"
  cp -a "$LIB_UDEV/rules.d/80-drivers.rules" "$TMP_MOUNT_PATH/lib/udev/rules.d"
  cp -a "$LIB_UDEV/firmware" "$TMP_MOUNT_PATH/lib/udev"
  # cjk adding for hwdiscovery support
  cp "/sbin/dhclient-script" "$TMP_MOUNT_PATH/sbin"

  mkdir -p "$TMP_MOUNT_PATH/etc/modprobe.d"
  echo "blacklist evbug" > "$TMP_MOUNT_PATH/etc/modprobe.d/blacklist.conf"

  # cjk adding for hwdiscovery support
  touch "$TMP_MOUNT_PATH/etc/fstab"

  mkdir -p "$TMP_MOUNT_PATH/etc/udev"
  cat >"$TMP_MOUNT_PATH/etc/udev/udev.conf" <<EOF

udev_root="/dev"
udev_rules="/lib/udev/rules.d"
udev_log="no"
EOF
}

function populate_lib () {
  echo "Populating /lib"

  libs=
  for i in "$BUSYBOX" "$LIB_UDEV/firmware" bash lsmod modprobe udevd udevadm wget reboot shutdown $BINARY_DEPS ; do
    if "$BUSYBOX" --list | grep "^$i\$" >/dev/null; then
      continue
    fi
    path=`which $i 2>/dev/null` || path=$i
    if ! [ -x "$path" ]; then
      echo "$i is not found in PATH" 2>&1
      exit 1
    fi
    cp -L "$path" "$TMP_MOUNT_PATH/bin/"
    if l=`ldd "$path"`; then
      l=$( echo "$l" | grep '/' | tr "\t" " " )
      l=$( echo "$l" | sed 's/^.* => \([^ ]*\).*$/\1/' )
      l=$( echo "$l" | sed 's/^ *\([^ ]*\) *(0x[0-9a-f]*)/\1/' )
      l=$( echo "$l" | tr " " "\n" )
      libs=$( printf "%s\n%s\n" "$l" "$libs" | sort | uniq )
    fi
  done
  cp $libs "$TMP_MOUNT_PATH/lib/"

  cp -a "$MODULE_DIR" "$TMP_MOUNT_PATH/lib/modules/$KERNEL_VERSION"
  cp -a "$FIRMWARE_DIR" "$TMP_MOUNT_PATH/lib/firmware"
}

function populate_busybox () {
  echo "Creating symlinks for busybox binaries"

  for i in $( "$BUSYBOX" --list ); do
    if [ -f "$TMP_MOUNT_PATH/bin/$i" ]; then
      echo "skip $i"
      continue
    fi
    ln -s busybox "$TMP_MOUNT_PATH/bin/$i"
  done
}

function populate_init () {
  echo "Installing init"
  cp "$INIT" "$TMP_MOUNT_PATH/init"
  chmod +x $TMP_MOUNT_PATH/init
  for F in "$FUNCTIONS_D"/* ; do
    cp "$F" "$TMP_MOUNT_PATH"
  done

  # Append /init with any element fragments that are present
  for _FLVR in ${RAMDISK_ELEMENT} ; do
    _FILE="${ELEMENTS_DIR}/${_FLVR}/init"
    if [ -a $_FILE ]; then
      cat >>$TMP_MOUNT_PATH/init <<EOF

# init fragment from ${_FLVR}
EOF
      cat <$_FILE >>$TMP_MOUNT_PATH/init
    fi  
  done

  # Add our final steps to /init
  cat <${INIT}-end >>$TMP_MOUNT_PATH/init
}

function finalise_image () {
  echo "Finalising image"
  (cd "$TMP_MOUNT_PATH"; find . | cpio -o -H newc | gzip > "$TMP_IMAGE_PATH" )
}

function populate_udev () {
  echo "Installing udev rules"

  for _FLVR in ${RAMDISK_ELEMENT} ; do
    _DIR="${ELEMENTS_DIR}/${_FLVR}/udev"
    if [ -d $_DIR ]; then
      find $_DIR -type f -exec cp -v {} $TMP_MOUNT_PATH/lib/udev/rules.d/ \;
    fi
  done
}