blob: 9bdae506cffed8615fdaf424fe1a0379477e3492
| 1 | /* vi: set sw=4 ts=4: */ |
| 2 | /* |
| 3 | * pivot_root.c - Change root file system. Based on util-linux 2.10s |
| 4 | * |
| 5 | * busyboxed by Evin Robertson |
| 6 | * pivot_root syscall stubbed by Erik Andersen, so it will compile |
| 7 | * regardless of the kernel being used. |
| 8 | * |
| 9 | * Licensed under GPLv2, see file LICENSE in this source tree. |
| 10 | */ |
| 11 | //config:config PIVOT_ROOT |
| 12 | //config: bool "pivot_root" |
| 13 | //config: default y |
| 14 | //config: select PLATFORM_LINUX |
| 15 | //config: help |
| 16 | //config: The pivot_root utility swaps the mount points for the root filesystem |
| 17 | //config: with some other mounted filesystem. This allows you to do all sorts |
| 18 | //config: of wild and crazy things with your Linux system and is far more |
| 19 | //config: powerful than 'chroot'. |
| 20 | //config: |
| 21 | //config: Note: This is for initrd in linux 2.4. Under initramfs (introduced |
| 22 | //config: in linux 2.6) use switch_root instead. |
| 23 | |
| 24 | //applet:IF_PIVOT_ROOT(APPLET(pivot_root, BB_DIR_SBIN, BB_SUID_DROP)) |
| 25 | |
| 26 | //kbuild:lib-$(CONFIG_PIVOT_ROOT) += pivot_root.o |
| 27 | |
| 28 | //usage:#define pivot_root_trivial_usage |
| 29 | //usage: "NEW_ROOT PUT_OLD" |
| 30 | //usage:#define pivot_root_full_usage "\n\n" |
| 31 | //usage: "Move the current root file system to PUT_OLD and make NEW_ROOT\n" |
| 32 | //usage: "the new root file system" |
| 33 | |
| 34 | #include "libbb.h" |
| 35 | |
| 36 | extern int pivot_root(const char * new_root,const char * put_old); |
| 37 | |
| 38 | int pivot_root_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| 39 | int pivot_root_main(int argc, char **argv) |
| 40 | { |
| 41 | if (argc != 3) |
| 42 | bb_show_usage(); |
| 43 | |
| 44 | if (pivot_root(argv[1], argv[2]) < 0) { |
| 45 | /* prints "pivot_root: <strerror text>" */ |
| 46 | bb_perror_nomsg_and_die(); |
| 47 | } |
| 48 | |
| 49 | return EXIT_SUCCESS; |
| 50 | } |
| 51 |