2 # For a description of the syntax of this configuration file,
3 # see scripts/kbuild/config-language.txt.
6 menu "Linux System Utilities"
8 config BUSYBOX_CONFIG_ACPID
12 acpid listens to ACPI events coming either in textual form from
13 /proc/acpi/event (though it is marked deprecated it is still widely
14 used and _is_ a standard) or in binary form from specified evdevs
15 (just use /dev/input/event*).
17 It parses the event to retrieve ACTION and a possible PARAMETER.
18 It then spawns /etc/acpi/<ACTION>[/<PARAMETER>] either via run-parts
19 (if the resulting path is a directory) or directly as an executable.
21 N.B. acpid relies on run-parts so have the latter installed.
23 config BUSYBOX_CONFIG_FEATURE_ACPID_COMPAT
24 bool "Accept and ignore redundant options"
26 depends on BUSYBOX_CONFIG_ACPID
28 Accept and ignore compatibility options -g -m -s -S -v.
30 config BUSYBOX_CONFIG_BLKID
33 select BUSYBOX_CONFIG_VOLUMEID
35 Lists labels and UUIDs of all filesystems.
37 With all submodules selected, it will add ~8k to busybox.
39 config BUSYBOX_CONFIG_DMESG
43 dmesg is used to examine or control the kernel ring buffer. When the
44 Linux kernel prints messages to the system log, they are stored in
45 the kernel ring buffer. You can use dmesg to print the kernel's ring
46 buffer, clear the kernel ring buffer, change the size of the kernel
47 ring buffer, and change the priority level at which kernel messages
48 are also logged to the system console. Enable this option if you
49 wish to enable the 'dmesg' utility.
51 config BUSYBOX_CONFIG_FEATURE_DMESG_PRETTY
52 bool "Pretty dmesg output"
54 depends on BUSYBOX_CONFIG_DMESG
56 If you wish to scrub the syslog level from the output, say 'Y' here.
57 The syslog level is a string prefixed to every line with the form
60 With this option you will see:
62 Linux version 2.6.17.4 .....
63 BIOS-provided physical RAM map:
64 BIOS-e820: 0000000000000000 - 000000000009f000 (usable)
66 Without this option you will see:
68 <5>Linux version 2.6.17.4 .....
69 <6>BIOS-provided physical RAM map:
70 <6> BIOS-e820: 0000000000000000 - 000000000009f000 (usable)
72 config BUSYBOX_CONFIG_FBSET
76 fbset is used to show or change the settings of a Linux frame buffer
77 device. The frame buffer device provides a simple and unique
78 interface to access a graphics display. Enable this option
79 if you wish to enable the 'fbset' utility.
81 config BUSYBOX_CONFIG_FEATURE_FBSET_FANCY
82 bool "Turn on extra fbset options"
84 depends on BUSYBOX_CONFIG_FBSET
86 This option enables extended fbset options, allowing one to set the
87 framebuffer size, color depth, etc. interface to access a graphics
88 display. Enable this option if you wish to enable extended fbset
91 config BUSYBOX_CONFIG_FEATURE_FBSET_READMODE
92 bool "Turn on fbset readmode support"
94 depends on BUSYBOX_CONFIG_FBSET
96 This option allows fbset to read the video mode database stored by
97 default n /etc/fb.modes, which can be used to set frame buffer
98 device to pre-defined video modes.
100 config BUSYBOX_CONFIG_FDFLUSH
104 fdflush is only needed when changing media on slightly-broken
105 removable media drives. It is used to make Linux believe that a
106 hardware disk-change switch has been actuated, which causes Linux to
107 forget anything it has cached from the previous media. If you have
108 such a slightly-broken drive, you will need to run fdflush every time
109 you change a disk. Most people have working hardware and can safely
112 config BUSYBOX_CONFIG_FDFORMAT
116 fdformat is used to low-level format a floppy disk.
118 config BUSYBOX_CONFIG_FDISK
122 The fdisk utility is used to divide hard disks into one or more
123 logical disks, which are generally called partitions. This utility
124 can be used to list and edit the set of partitions or BSD style
125 'disk slices' that are defined on a hard drive.
127 config BUSYBOX_CONFIG_FDISK_SUPPORT_LARGE_DISKS
128 bool "Support over 4GB disks"
130 depends on BUSYBOX_CONFIG_FDISK
132 Enable this option to support large disks > 4GB.
134 config BUSYBOX_CONFIG_FEATURE_FDISK_WRITABLE
137 depends on BUSYBOX_CONFIG_FDISK
139 Enabling this option allows you to create or change a partition table
140 and write those changes out to disk. If you leave this option
141 disabled, you will only be able to view the partition table.
143 config BUSYBOX_CONFIG_FEATURE_AIX_LABEL
144 bool "Support AIX disklabels"
146 depends on BUSYBOX_CONFIG_FDISK && BUSYBOX_CONFIG_FEATURE_FDISK_WRITABLE
148 Enabling this option allows you to create or change AIX disklabels.
149 Most people can safely leave this option disabled.
151 config BUSYBOX_CONFIG_FEATURE_SGI_LABEL
152 bool "Support SGI disklabels"
154 depends on BUSYBOX_CONFIG_FDISK && BUSYBOX_CONFIG_FEATURE_FDISK_WRITABLE
156 Enabling this option allows you to create or change SGI disklabels.
157 Most people can safely leave this option disabled.
159 config BUSYBOX_CONFIG_FEATURE_SUN_LABEL
160 bool "Support SUN disklabels"
162 depends on BUSYBOX_CONFIG_FDISK && BUSYBOX_CONFIG_FEATURE_FDISK_WRITABLE
164 Enabling this option allows you to create or change SUN disklabels.
165 Most people can safely leave this option disabled.
167 config BUSYBOX_CONFIG_FEATURE_OSF_LABEL
168 bool "Support BSD disklabels"
170 depends on BUSYBOX_CONFIG_FDISK && BUSYBOX_CONFIG_FEATURE_FDISK_WRITABLE
172 Enabling this option allows you to create or change BSD disklabels
173 and define and edit BSD disk slices.
175 config BUSYBOX_CONFIG_FEATURE_FDISK_ADVANCED
176 bool "Support expert mode"
178 depends on BUSYBOX_CONFIG_FDISK && BUSYBOX_CONFIG_FEATURE_FDISK_WRITABLE
180 Enabling this option allows you to do terribly unsafe things like
181 define arbitrary drive geometry, move the beginning of data in a
182 partition, and similarly evil things. Unless you have a very good
183 reason you would be wise to leave this disabled.
185 config BUSYBOX_CONFIG_FINDFS
188 select BUSYBOX_CONFIG_VOLUMEID
190 Prints the name of a filesystem with given label or UUID.
192 With all submodules selected, it will add ~8k to busybox.
194 config BUSYBOX_CONFIG_FREERAMDISK
198 Linux allows you to create ramdisks. This utility allows you to
199 delete them and completely free all memory that was used for the
200 ramdisk. For example, if you boot Linux into a ramdisk and later
201 pivot_root, you may want to free the memory that is allocated to the
202 ramdisk. If you have no use for freeing memory from a ramdisk, leave
205 config BUSYBOX_CONFIG_FSCK_MINIX
209 The minix filesystem is a nice, small, compact, read-write filesystem
210 with little overhead. It is not a journaling filesystem however and
211 can experience corruption if it is not properly unmounted or if the
212 power goes off in the middle of a write. This utility allows you to
213 check for and attempt to repair any corruption that occurs to a minix
216 config BUSYBOX_CONFIG_MKFS_MINIX
220 The minix filesystem is a nice, small, compact, read-write filesystem
221 with little overhead. If you wish to be able to create minix
222 filesystems this utility will do the job for you.
224 comment "Minix filesystem support"
225 depends on BUSYBOX_CONFIG_FSCK_MINIX || BUSYBOX_CONFIG_MKFS_MINIX
227 config BUSYBOX_CONFIG_FEATURE_MINIX2
228 bool "Support Minix fs v2 (fsck_minix/mkfs_minix)"
230 depends on BUSYBOX_CONFIG_FSCK_MINIX || BUSYBOX_CONFIG_MKFS_MINIX
232 If you wish to be able to create version 2 minix filesystems, enable
233 this. If you enabled 'mkfs_minix' then you almost certainly want to
234 be using the version 2 filesystem support.
236 config BUSYBOX_CONFIG_MKFS_VFAT
240 Utility to create FAT32 filesystems.
242 config BUSYBOX_CONFIG_GETOPT
246 The getopt utility is used to break up (parse) options in command
247 lines to make it easy to write complex shell scripts that also check
248 for legal (and illegal) options. If you want to write horribly
249 complex shell scripts, or use some horribly complex shell script
250 written by others, this utility may be for you. Most people will
251 wisely leave this disabled.
253 config BUSYBOX_CONFIG_HEXDUMP
257 The hexdump utility is used to display binary data in a readable
258 way that is comparable to the output from most hex editors.
260 config BUSYBOX_CONFIG_FEATURE_HEXDUMP_REVERSE
261 bool "Support -R, reverse of 'hexdump -Cv'"
263 depends on BUSYBOX_CONFIG_HEXDUMP
265 The hexdump utility is used to display binary data in an ascii
266 readable way. This option creates binary data from an ascii input.
267 NB: this option is non-standard. It's unwise to use it in scripts
268 aimed to be portable.
270 config BUSYBOX_CONFIG_HD
273 select BUSYBOX_CONFIG_HEXDUMP
275 hd is an alias to hexdump -C.
277 config BUSYBOX_CONFIG_HWCLOCK
281 The hwclock utility is used to read and set the hardware clock
282 on a system. This is primarily used to set the current time on
283 shutdown in the hardware clock, so the hardware will keep the
284 correct time when Linux is _not_ running.
286 config BUSYBOX_CONFIG_FEATURE_HWCLOCK_LONG_OPTIONS
287 bool "Support long options (--hctosys,...)"
289 depends on BUSYBOX_CONFIG_HWCLOCK && BUSYBOX_CONFIG_GETOPT_LONG
291 By default, the hwclock utility only uses short options. If you
292 are overly fond of its long options, such as --hctosys, --utc, etc)
293 then enable this option.
295 config BUSYBOX_CONFIG_FEATURE_HWCLOCK_ADJTIME_FHS
296 bool "Use FHS /var/lib/hwclock/adjtime"
298 depends on BUSYBOX_CONFIG_HWCLOCK
300 Starting with FHS 2.3, the adjtime state file is supposed to exist
301 at /var/lib/hwclock/adjtime instead of /etc/adjtime. If you wish
302 to use the FHS behavior, answer Y here, otherwise answer N for the
303 classic /etc/adjtime path.
305 pathname.com/fhs/pub/fhs-2.3.html#VARLIBHWCLOCKSTATEDIRECTORYFORHWCLO
307 config BUSYBOX_CONFIG_IPCRM
310 select BUSYBOX_CONFIG_FEATURE_SUID
312 The ipcrm utility allows the removal of System V interprocess
313 communication (IPC) objects and the associated data structures
316 config BUSYBOX_CONFIG_IPCS
319 select BUSYBOX_CONFIG_FEATURE_SUID
321 The ipcs utility is used to provide information on the currently
322 allocated System V interprocess (IPC) objects in the system.
324 config BUSYBOX_CONFIG_LOSETUP
328 losetup is used to associate or detach a loop device with a regular
329 file or block device, and to query the status of a loop device. This
330 version does not currently support enabling data encryption.
332 config BUSYBOX_CONFIG_MDEV
336 mdev is a mini-udev implementation for dynamically creating device
337 nodes in the /dev directory.
339 For more information, please see docs/mdev.txt
341 config BUSYBOX_CONFIG_FEATURE_MDEV_CONF
342 bool "Support /etc/mdev.conf"
344 depends on BUSYBOX_CONFIG_MDEV
346 Add support for the mdev config file to control ownership and
347 permissions of the device nodes.
349 For more information, please see docs/mdev.txt
351 config BUSYBOX_CONFIG_FEATURE_MDEV_RENAME
352 bool "Support subdirs/symlinks"
354 depends on BUSYBOX_CONFIG_FEATURE_MDEV_CONF
356 Add support for renaming devices and creating symlinks.
358 For more information, please see docs/mdev.txt
360 config BUSYBOX_CONFIG_FEATURE_MDEV_RENAME_REGEXP
361 bool "Support regular expressions substitutions when renaming device"
363 depends on BUSYBOX_CONFIG_FEATURE_MDEV_RENAME
365 Add support for regular expressions substitutions when renaming
368 config BUSYBOX_CONFIG_FEATURE_MDEV_EXEC
369 bool "Support command execution at device addition/removal"
371 depends on BUSYBOX_CONFIG_FEATURE_MDEV_CONF
373 This adds support for an optional field to /etc/mdev.conf for
374 executing commands when devices are created/removed.
376 For more information, please see docs/mdev.txt
378 config BUSYBOX_CONFIG_FEATURE_MDEV_LOAD_FIRMWARE
379 bool "Support loading of firmwares"
381 depends on BUSYBOX_CONFIG_MDEV
383 Some devices need to load firmware before they can be usable.
385 These devices will request userspace look up the files in
386 /lib/firmware/ and if it exists, send it to the kernel for
387 loading into the hardware.
389 config BUSYBOX_CONFIG_MKSWAP
393 The mkswap utility is used to configure a file or disk partition as
394 Linux swap space. This allows Linux to use the entire file or
395 partition as if it were additional RAM, which can greatly increase
396 the capability of low-memory machines. This additional memory is
397 much slower than real RAM, but can be very helpful at preventing your
398 applications being killed by the Linux out of memory (OOM) killer.
399 Once you have created swap space using 'mkswap' you need to enable
400 the swap space using the 'swapon' utility.
402 config BUSYBOX_CONFIG_FEATURE_MKSWAP_V0
403 bool "Version 0 support"
405 depends on BUSYBOX_CONFIG_MKSWAP
406 # depends on MKSWAP && BUSYBOX_CONFIG_DEPRECATED
408 Enable support for the old v0 style.
409 If your kernel is older than 2.1.117, then v0 support is the
412 config BUSYBOX_CONFIG_MORE
416 more is a simple utility which allows you to read text one screen
417 sized page at a time. If you want to read text that is larger than
418 the screen, and you are using anything faster than a 300 baud modem,
419 you will probably find this utility very helpful. If you don't have
420 any need to reading text files, you can leave this disabled.
422 config BUSYBOX_CONFIG_FEATURE_USE_TERMIOS
423 bool "Use termios to manipulate the screen"
425 depends on BUSYBOX_CONFIG_MORE || BUSYBOX_CONFIG_TOP
427 This option allows utilities such as 'more' and 'top' to determine
428 the size of the screen. If you leave this disabled, your utilities
429 that display things on the screen will be especially primitive and
430 will be unable to determine the current screen size, and will be
431 unable to move the cursor.
433 config BUSYBOX_CONFIG_VOLUMEID
434 bool #No description makes it a hidden option
437 config BUSYBOX_CONFIG_FEATURE_VOLUMEID_EXT
438 bool "Ext filesystem"
440 depends on BUSYBOX_CONFIG_VOLUMEID
444 config BUSYBOX_CONFIG_FEATURE_VOLUMEID_REISERFS
445 bool "Reiser filesystem"
447 depends on BUSYBOX_CONFIG_VOLUMEID
451 config BUSYBOX_CONFIG_FEATURE_VOLUMEID_FAT
452 bool "fat filesystem"
454 depends on BUSYBOX_CONFIG_VOLUMEID
458 config BUSYBOX_CONFIG_FEATURE_VOLUMEID_HFS
459 bool "hfs filesystem"
461 depends on BUSYBOX_CONFIG_VOLUMEID
465 config BUSYBOX_CONFIG_FEATURE_VOLUMEID_JFS
466 bool "jfs filesystem"
468 depends on BUSYBOX_CONFIG_VOLUMEID
472 ### config FEATURE_VOLUMEID_UFS
473 ### bool "ufs filesystem"
475 ### depends on VOLUMEID
479 config BUSYBOX_CONFIG_FEATURE_VOLUMEID_XFS
480 bool "xfs filesystem"
482 depends on BUSYBOX_CONFIG_VOLUMEID
486 config BUSYBOX_CONFIG_FEATURE_VOLUMEID_NTFS
487 bool "ntfs filesystem"
489 depends on BUSYBOX_CONFIG_VOLUMEID
493 config BUSYBOX_CONFIG_FEATURE_VOLUMEID_ISO9660
494 bool "iso9660 filesystem"
496 depends on BUSYBOX_CONFIG_VOLUMEID
500 config BUSYBOX_CONFIG_FEATURE_VOLUMEID_UDF
501 bool "udf filesystem"
503 depends on BUSYBOX_CONFIG_VOLUMEID
507 config BUSYBOX_CONFIG_FEATURE_VOLUMEID_LUKS
508 bool "luks filesystem"
510 depends on BUSYBOX_CONFIG_VOLUMEID
514 config BUSYBOX_CONFIG_FEATURE_VOLUMEID_LINUXSWAP
515 bool "linux swap filesystem"
517 depends on BUSYBOX_CONFIG_VOLUMEID
521 ### config FEATURE_VOLUMEID_LVM
524 ### depends on VOLUMEID
528 config BUSYBOX_CONFIG_FEATURE_VOLUMEID_CRAMFS
529 bool "cramfs filesystem"
531 depends on BUSYBOX_CONFIG_VOLUMEID
535 ### config FEATURE_VOLUMEID_HPFS
536 ### bool "hpfs filesystem"
538 ### depends on VOLUMEID
542 config BUSYBOX_CONFIG_FEATURE_VOLUMEID_ROMFS
543 bool "romfs filesystem"
545 depends on BUSYBOX_CONFIG_VOLUMEID
549 config BUSYBOX_CONFIG_FEATURE_VOLUMEID_SYSV
550 bool "sysv filesystem"
552 depends on BUSYBOX_CONFIG_VOLUMEID
556 ### config FEATURE_VOLUMEID_MINIX
557 ### bool "minix filesystem"
559 ### depends on VOLUMEID
563 ### These only detect partition tables - not used (yet?)
564 ### config FEATURE_VOLUMEID_MAC
565 ### bool "mac filesystem"
567 ### depends on VOLUMEID
571 ### config FEATURE_VOLUMEID_MSDOS
572 ### bool "msdos filesystem"
574 ### depends on VOLUMEID
578 config BUSYBOX_CONFIG_FEATURE_VOLUMEID_OCFS2
579 bool "ocfs2 filesystem"
581 depends on BUSYBOX_CONFIG_VOLUMEID
585 ### config FEATURE_VOLUMEID_HIGHPOINTRAID
586 ### bool "highpoint raid"
588 ### depends on VOLUMEID
592 ### config FEATURE_VOLUMEID_ISWRAID
593 ### bool "intel raid"
595 ### depends on VOLUMEID
599 ### config FEATURE_VOLUMEID_LSIRAID
602 ### depends on VOLUMEID
606 ### config FEATURE_VOLUMEID_VIARAID
609 ### depends on VOLUMEID
613 ### config FEATURE_VOLUMEID_SILICONRAID
614 ### bool "silicon raid"
616 ### depends on VOLUMEID
620 ### config FEATURE_VOLUMEID_NVIDIARAID
621 ### bool "nvidia raid"
623 ### depends on VOLUMEID
627 ### config FEATURE_VOLUMEID_PROMISERAID
628 ### bool "promise raid"
630 ### depends on VOLUMEID
634 config BUSYBOX_CONFIG_FEATURE_VOLUMEID_LINUXRAID
637 depends on BUSYBOX_CONFIG_VOLUMEID
641 config BUSYBOX_CONFIG_MOUNT
645 All files and filesystems in Unix are arranged into one big directory
646 tree. The 'mount' utility is used to graft a filesystem onto a
647 particular part of the tree. A filesystem can either live on a block
648 device, or it can be accessible over the network, as is the case with
649 NFS filesystems. Most people using BusyBox will also want to enable
652 config BUSYBOX_CONFIG_FEATURE_MOUNT_FAKE
653 bool "Support option -f"
655 depends on BUSYBOX_CONFIG_MOUNT
657 Enable support for faking a file system mount.
659 config BUSYBOX_CONFIG_FEATURE_MOUNT_VERBOSE
660 bool "Support option -v"
662 depends on BUSYBOX_CONFIG_MOUNT
664 Enable multi-level -v[vv...] verbose messages. Useful if you
665 debug mount problems and want to see what is exactly passed
668 config BUSYBOX_CONFIG_FEATURE_MOUNT_HELPERS
669 bool "Support mount helpers"
671 depends on BUSYBOX_CONFIG_MOUNT
673 Enable mounting of virtual file systems via external helpers.
674 E.g. "mount obexfs#-b00.11.22.33.44.55 /mnt" will in effect call
675 "obexfs -b00.11.22.33.44.55 /mnt"
676 Also "mount -t sometype [-o opts] fs /mnt" will try
677 "sometype [-o opts] fs /mnt" if simple mount syscall fails.
678 The idea is to use such virtual filesystems in /etc/fstab.
680 config BUSYBOX_CONFIG_FEATURE_MOUNT_LABEL
681 bool "Support specifiying devices by label or UUID"
683 depends on BUSYBOX_CONFIG_MOUNT
684 select BUSYBOX_CONFIG_VOLUMEID
686 This allows for specifying a device by label or uuid, rather than by
687 name. This feature utilizes the same functionality as blkid/findfs.
689 config BUSYBOX_CONFIG_FEATURE_MOUNT_NFS
690 bool "Support mounting NFS file systems"
692 depends on BUSYBOX_CONFIG_MOUNT
693 select BUSYBOX_CONFIG_FEATURE_HAVE_RPC
694 select BUSYBOX_CONFIG_FEATURE_SYSLOG
696 Enable mounting of NFS file systems.
698 config BUSYBOX_CONFIG_FEATURE_MOUNT_CIFS
699 bool "Support mounting CIFS/SMB file systems"
701 depends on BUSYBOX_CONFIG_MOUNT
703 Enable support for samba mounts.
705 config BUSYBOX_CONFIG_FEATURE_MOUNT_FLAGS
706 depends on BUSYBOX_CONFIG_MOUNT
707 bool "Support lots of -o flags in mount"
710 Without this, mount only supports ro/rw/remount. With this, it
711 supports nosuid, suid, dev, nodev, exec, noexec, sync, async, atime,
712 noatime, diratime, nodiratime, loud, bind, move, shared, slave,
713 private, unbindable, rshared, rslave, rprivate, and runbindable.
715 config BUSYBOX_CONFIG_FEATURE_MOUNT_FSTAB
716 depends on BUSYBOX_CONFIG_MOUNT
717 bool "Support /etc/fstab and -a"
720 Support mount all and looking for files in /etc/fstab.
722 config BUSYBOX_CONFIG_PIVOT_ROOT
726 The pivot_root utility swaps the mount points for the root filesystem
727 with some other mounted filesystem. This allows you to do all sorts
728 of wild and crazy things with your Linux system and is far more
729 powerful than 'chroot'.
731 Note: This is for initrd in linux 2.4. Under initramfs (introduced
732 in linux 2.6) use switch_root instead.
734 config BUSYBOX_CONFIG_RDATE
738 The rdate utility allows you to synchronize the date and time of your
739 system clock with the date and time of a remote networked system using
740 the RFC868 protocol, which is built into the inetd daemon on most
743 config BUSYBOX_CONFIG_RDEV
747 Print the device node associated with the filesystem mounted at '/'.
749 config BUSYBOX_CONFIG_READPROFILE
753 This allows you to parse /proc/profile for basic profiling.
755 config BUSYBOX_CONFIG_RTCWAKE
759 Enter a system sleep state until specified wakeup time.
761 config BUSYBOX_CONFIG_SCRIPT
765 The script makes typescript of terminal session.
767 config BUSYBOX_CONFIG_SETARCH
771 The linux32 utility is used to create a 32bit environment for the
772 specified program (usually a shell). It only makes sense to have
773 this util on a system that supports both 64bit and 32bit userland
774 (like amd64/x86, ppc64/ppc, sparc64/sparc, etc...).
776 config BUSYBOX_CONFIG_SWAPONOFF
780 This option enables both the 'swapon' and the 'swapoff' utilities.
781 Once you have created some swap space using 'mkswap', you also need
782 to enable your swap space with the 'swapon' utility. The 'swapoff'
783 utility is used, typically at system shutdown, to disable any swap
784 space. If you are not using any swap space, you can leave this
787 config BUSYBOX_CONFIG_FEATURE_SWAPON_PRI
788 bool "Support priority option -p"
790 depends on BUSYBOX_CONFIG_SWAPONOFF
792 Enable support for setting swap device priority in swapon.
794 config BUSYBOX_CONFIG_SWITCH_ROOT
798 The switch_root utility is used from initramfs to select a new
799 root device. Under initramfs, you have to use this instead of
800 pivot_root. (Stop reading here if you don't care why.)
802 Booting with initramfs extracts a gzipped cpio archive into rootfs
803 (which is a variant of ramfs/tmpfs). Because rootfs can't be moved
804 or unmounted*, pivot_root will not work from initramfs. Instead,
805 switch_root deletes everything out of rootfs (including itself),
806 does a mount --move that overmounts rootfs with the new root, and
807 then execs the specified init program.
809 * Because the Linux kernel uses rootfs internally as the starting
810 and ending point for searching through the kernel's doubly linked
811 list of active mount points. That's why.
813 config BUSYBOX_CONFIG_UMOUNT
817 When you want to remove a mounted filesystem from its current mount
818 point, for example when you are shutting down the system, the
819 'umount' utility is the tool to use. If you enabled the 'mount'
820 utility, you almost certainly also want to enable 'umount'.
822 config BUSYBOX_CONFIG_FEATURE_UMOUNT_ALL
823 bool "Support option -a"
825 depends on BUSYBOX_CONFIG_UMOUNT
827 Support -a option to unmount all currently mounted filesystems.
829 comment "Common options for mount/umount"
830 depends on BUSYBOX_CONFIG_MOUNT || BUSYBOX_CONFIG_UMOUNT
832 config BUSYBOX_CONFIG_FEATURE_MOUNT_LOOP
833 bool "Support loopback mounts"
835 depends on BUSYBOX_CONFIG_MOUNT || BUSYBOX_CONFIG_UMOUNT
837 Enabling this feature allows automatic mounting of files (containing
838 filesystem images) via the linux kernel's loopback devices.
839 The mount command will detect you are trying to mount a file instead
840 of a block device, and transparently associate the file with a
841 loopback device. The umount command will also free that loopback
844 You can still use the 'losetup' utility (to manually associate files
845 with loop devices) if you need to do something advanced, such as
846 specify an offset or cryptographic options to the loopback device.
847 (If you don't want umount to free the loop device, use "umount -D".)
849 config BUSYBOX_CONFIG_FEATURE_MTAB_SUPPORT
850 bool "Support for the old /etc/mtab file"
852 depends on BUSYBOX_CONFIG_MOUNT || BUSYBOX_CONFIG_UMOUNT
853 select BUSYBOX_CONFIG_FEATURE_MOUNT_FAKE
855 Historically, Unix systems kept track of the currently mounted
856 partitions in the file "/etc/mtab". These days, the kernel exports
857 the list of currently mounted partitions in "/proc/mounts", rendering
858 the old mtab file obsolete. (In modern systems, /etc/mtab should be
859 a symlink to /proc/mounts.)
861 The only reason to have mount maintain an /etc/mtab file itself is if
862 your stripped-down embedded system does not have a /proc directory.
863 If you must use this, keep in mind it's inherently brittle (for
864 example a mount under chroot won't update it), can't handle modern
865 features like separate per-process filesystem namespaces, requires
866 that your /etc directory be writeable, tends to get easily confused
867 by --bind or --move mounts, won't update if you rename a directory
868 that contains a mount point, and so on. (In brief: avoid.)
870 About the only reason to use this is if you've removed /proc from