2 * run-init implementation for busybox
   3 *
   4 * Copyright (c) 2017 Denys Vlasenko <vda.linux@gmail.com>
   5 *
   6 * Licensed under GPLv2, see file LICENSE in this source tree.
   7 */
   8//config:config RUN_INIT
   9//config:       bool "run-init (7.7 kb)"
  10//config:       default y
  11//config:       help
  12//config:       The run-init utility is used from initramfs to select a new
  13//config:       root device. Under initramfs, you have to use this instead of
  14//config:       pivot_root.
  16//config:       Booting with initramfs extracts a gzipped cpio archive into rootfs
  17//config:       (which is a variant of ramfs/tmpfs). Because rootfs can't be moved
  18//config:       or unmounted, pivot_root will not work from initramfs. Instead,
  19//config:       run-init deletes everything out of rootfs (including itself),
  20//config:       does a mount --move that overmounts rootfs with the new root, and
  21//config:       then execs the specified init program.
  23//config:       util-linux has a similar tool, switch-root.
  24//config:       run-init differs by also having a "-d CAPS_TO_DROP" option.
  26/* applet and kbuild hooks are in switch_root.c */