2 # For a description of the syntax of this configuration file,
3 # see scripts/kbuild/config-language.txt.
6 menu "Linux System Utilities"
12 dmesg is used to examine or control the kernel ring buffer. When the
13 Linux kernel prints messages to the system log, they are stored in
14 the kernel ring buffer. You can use dmesg to print the kernel's ring
15 buffer, clear the kernel ring buffer, change the size of the kernel
16 ring buffer, and change the priority level at which kernel messages
17 are also logged to the system console. Enable this option if you
18 wish to enable the 'dmesg' utility.
20 config FEATURE_DMESG_PRETTY
21 bool "pretty dmesg output"
25 If you wish to scrub the syslog level from the output, say 'Y' here.
26 The syslog level is a string prefixed to every line with the form "<#>".
28 With this option you will see:
30 Linux version 2.6.17.4 .....
31 BIOS-provided physical RAM map:
32 BIOS-e820: 0000000000000000 - 000000000009f000 (usable)
34 Without this option you will see:
36 <5>Linux version 2.6.17.4 .....
37 <6>BIOS-provided physical RAM map:
38 <6> BIOS-e820: 0000000000000000 - 000000000009f000 (usable)
44 fbset is used to show or change the settings of a Linux frame buffer
45 device. The frame buffer device provides a simple and unique
46 interface to access a graphics display. Enable this option
47 if you wish to enable the 'fbset' utility.
49 config FEATURE_FBSET_FANCY
50 bool "Turn on extra fbset options"
54 This option enables extended fbset options, allowing one to set the
55 framebuffer size, color depth, etc. interface to access a graphics
56 display. Enable this option if you wish to enable extended fbset
59 config FEATURE_FBSET_READMODE
60 bool "Turn on fbset readmode support"
64 This option allows fbset to read the video mode database stored by
65 default as /etc/fb.modes, which can be used to set frame buffer
66 device to pre-defined video modes.
72 fdflush is only needed when changing media on slightly-broken
73 removable media drives. It is used to make Linux believe that a
74 hardware disk-change switch has been actuated, which causes Linux to
75 forget anything it has cached from the previous media. If you have
76 such a slightly-broken drive, you will need to run fdflush every time
77 you change a disk. Most people have working hardware and can safely
84 fdformat is used to low-level format a floppy disk.
90 The fdisk utility is used to divide hard disks into one or more
91 logical disks, which are generally called partitions. This utility
92 can be used to list and edit the set of partitions or BSD style
93 'disk slices' that are defined on a hard drive.
95 config FDISK_SUPPORT_LARGE_DISKS
96 bool "support over 4GB disks"
100 Enable this option to support large disks > 4GB.
102 config FEATURE_FDISK_WRITABLE
107 Enabling this option allows you to create or change a partition table
108 and write those changes out to disk. If you leave this option
109 disabled, you will only be able to view the partition table.
111 config FEATURE_AIX_LABEL
112 bool "Support AIX disklabels"
114 depends on FDISK && FEATURE_FDISK_WRITABLE
116 Enabling this option allows you to create or change AIX disklabels.
117 Most people can safely leave this option disabled.
119 config FEATURE_SGI_LABEL
120 bool "Support SGI disklabels"
122 depends on FDISK && FEATURE_FDISK_WRITABLE
124 Enabling this option allows you to create or change SGI disklabels.
125 Most people can safely leave this option disabled.
127 config FEATURE_SUN_LABEL
128 bool "Support SUN disklabels"
130 depends on FDISK && FEATURE_FDISK_WRITABLE
132 Enabling this option allows you to create or change SUN disklabels.
133 Most people can safely leave this option disabled.
135 config FEATURE_OSF_LABEL
136 bool "Support BSD disklabels"
138 depends on FDISK && FEATURE_FDISK_WRITABLE
140 Enabling this option allows you to create or change BSD disklabels
141 and define and edit BSD disk slices.
143 config FEATURE_FDISK_ADVANCED
144 bool "Support expert mode"
146 depends on FDISK && FEATURE_FDISK_WRITABLE
148 Enabling this option allows you to do terribly unsafe things like
149 define arbitrary drive geometry, move the beginning of data in a
150 partition, and similarly evil things. Unless you have a very good
151 reason you would be wise to leave this disabled.
157 Linux allows you to create ramdisks. This utility allows you to
158 delete them and completely free all memory that was used for the
159 ramdisk. For example, if you boot Linux into a ramdisk and later
160 pivot_root, you may want to free the memory that is allocated to the
161 ramdisk. If you have no use for freeing memory from a ramdisk, leave
168 The minix filesystem is a nice, small, compact, read-write filesystem
169 with little overhead. It is not a journaling filesystem however and
170 can experience corruption if it is not properly unmounted or if the
171 power goes off in the middle of a write. This utility allows you to
172 check for and attempt to repair any corruption that occurs to a minix
179 The minix filesystem is a nice, small, compact, read-write filesystem
180 with little overhead. If you wish to be able to create minix filesystems
181 this utility will do the job for you.
183 comment "Minix filesystem support"
184 depends on FSCK_MINIX || MKFS_MINIX
186 config FEATURE_MINIX2
187 bool "Support Minix fs v2 (fsck_minix/mkfs_minix)"
189 depends on FSCK_MINIX || MKFS_MINIX
191 If you wish to be able to create version 2 minix filesystems, enable this.
192 If you enabled 'mkfs_minix' then you almost certainly want to be using the
193 version 2 filesystem support.
199 The getopt utility is used to break up (parse) options in command
200 lines to make it easy to write complex shell scripts that also check
201 for legal (and illegal) options. If you want to write horribly
202 complex shell scripts, or use some horribly complex shell script
203 written by others, this utility may be for you. Most people will
204 wisely leave this disabled.
210 The hexdump utility is used to display binary data in a readable
211 way that is comparable to the output from most hex editors.
218 hd is an alias to hexdump -C.
220 config FEATURE_HEXDUMP_REVERSE
221 bool "Support -R, reverse of 'hexdump -Cv'"
225 The hexdump utility is used to display binary data in an ascii
226 readable way. This option creates binary data from an ascii input.
227 NB: this option is non-standard. It's unwise to use it in scripts
228 aimed to be portable.
234 The hwclock utility is used to read and set the hardware clock
235 on a system. This is primarily used to set the current time on
236 shutdown in the hardware clock, so the hardware will keep the
237 correct time when Linux is _not_ running.
239 config FEATURE_HWCLOCK_LONG_OPTIONS
240 bool "Support long options (--hctosys,...)"
242 depends on HWCLOCK && GETOPT_LONG
244 By default, the hwclock utility only uses short options. If you
245 are overly fond of its long options, such as --hctosys, --utc, etc)
246 then enable this option.
248 config FEATURE_HWCLOCK_ADJTIME_FHS
249 bool "Use FHS /var/lib/hwclock/adjtime"
253 Starting with FHS 2.3, the adjtime state file is supposed to exist
254 at /var/lib/hwclock/adjtime instead of /etc/adjtime. If you wish
255 to use the FHS behavior, answer Y here, otherwise answer N for the
256 classic /etc/adjtime path.
258 http://www.pathname.com/fhs/pub/fhs-2.3.html#VARLIBHWCLOCKSTATEDIRECTORYFORHWCLO
265 The ipcrm utility allows the removal of System V interprocess
266 communication (IPC) objects and the associated data structures
274 The ipcs utility is used to provide information on the currently
275 allocated System V interprocess (IPC) objects in the system.
281 losetup is used to associate or detach a loop device with a regular
282 file or block device, and to query the status of a loop device. This
283 version does not currently support enabling data encryption.
289 mdev is a mini-udev implementation for dynamically creating device
290 nodes in the /dev directory.
292 For more information, please see docs/mdev.txt
294 config FEATURE_MDEV_CONF
295 bool "Support /etc/mdev.conf"
299 Add support for the mdev config file to control ownership and
300 permissions of the device nodes.
302 For more information, please see docs/mdev.txt
304 config FEATURE_MDEV_RENAME
305 bool "Support subdirs/symlinks"
307 depends on FEATURE_MDEV_CONF
309 Add support for renaming devices and creating symlinks.
311 For more information, please see docs/mdev.txt
313 config FEATURE_MDEV_EXEC
314 bool "Support command execution at device addition/removal"
316 depends on FEATURE_MDEV_CONF
318 This adds support for an optional field to /etc/mdev.conf for
319 executing commands when devices are created/removed.
321 For more information, please see docs/mdev.txt
323 config FEATURE_MDEV_LOAD_FIRMWARE
324 bool "Support loading of firmwares"
328 Some devices need to load firmware before they can be usable.
330 These devices will request userspace look up the files in
331 /lib/firmware/ and if it exists, send it to the kernel for
332 loading into the hardware.
338 The mkswap utility is used to configure a file or disk partition as
339 Linux swap space. This allows Linux to use the entire file or
340 partition as if it were additional RAM, which can greatly increase
341 the capability of low-memory machines. This additional memory is
342 much slower than real RAM, but can be very helpful at preventing your
343 applications being killed by the Linux out of memory (OOM) killer.
344 Once you have created swap space using 'mkswap' you need to enable
345 the swap space using the 'swapon' utility.
347 config FEATURE_MKSWAP_V0
348 bool "version 0 support"
351 # depends on MKSWAP && DEPRECATED
353 Enable support for the old v0 style.
354 If your kernel is older than 2.1.117, then v0 support is the
361 more is a simple utility which allows you to read text one screen
362 sized page at a time. If you want to read text that is larger than
363 the screen, and you are using anything faster than a 300 baud modem,
364 you will probably find this utility very helpful. If you don't have
365 any need to reading text files, you can leave this disabled.
367 config FEATURE_USE_TERMIOS
368 bool "Use termios to manipulate the screen"
372 This option allows utilities such as 'more' and 'top' to determine
373 the size of the screen. If you leave this disabled, your utilities
374 that display things on the screen will be especially primitive and
375 will be unable to determine the current screen size, and will be
376 unable to move the cursor.
382 All files and filesystems in Unix are arranged into one big directory
383 tree. The 'mount' utility is used to graft a filesystem onto a
384 particular part of the tree. A filesystem can either live on a block
385 device, or it can be accessible over the network, as is the case with
386 NFS filesystems. Most people using BusyBox will also want to enable
389 config FEATURE_MOUNT_FAKE
390 bool "mount -f option"
394 Enable support for faking a file system mount.
396 config FEATURE_MOUNT_HELPERS
397 bool "Support mount helpers"
401 Enable mounting of virtual file systems via external helpers.
402 E.g. "mount obexfs#-b00.11.22.33.44.55 /mnt" will in effect call
403 "obexfs -b00.11.22.33.44.55 /mnt"
404 Also "mount -t sometype [-o opts] fs /mnt" will try
405 "sometype [-o opts] fs /mnt" if simple mount syscall fails.
406 The idea is to use such virtual filesystems in /etc/fstab.
408 config FEATURE_MOUNT_NFS
409 bool "Support mounting NFS file systems"
412 select FEATURE_HAVE_RPC
413 select FEATURE_SYSLOG
415 Enable mounting of NFS file systems.
417 config FEATURE_MOUNT_CIFS
418 bool "Support mounting CIFS/SMB file systems"
422 Enable support for samba mounts.
424 config FEATURE_MOUNT_FLAGS
426 bool "Support lots of -o flags in mount"
429 Without this, mount only supports ro/rw/remount. With this, it
430 supports nosuid, suid, dev, nodev, exec, noexec, sync, async, atime,
431 noatime, diratime, nodiratime, loud, bind, move, shared, slave,
432 private, unbindable, rshared, rslave, rprivate, and runbindable.
434 config FEATURE_MOUNT_FSTAB
436 bool "Support /etc/fstab and -a"
439 Support mount all and looking for files in /etc/fstab.
445 The pivot_root utility swaps the mount points for the root filesystem
446 with some other mounted filesystem. This allows you to do all sorts
447 of wild and crazy things with your Linux system and is far more
448 powerful than 'chroot'.
450 Note: This is for initrd in linux 2.4. Under initramfs (introduced
451 in linux 2.6) use switch_root instead.
457 The rdate utility allows you to synchronize the date and time of your
458 system clock with the date and time of a remote networked system using
459 the RFC868 protocol, which is built into the inetd daemon on most
466 This allows you to parse /proc/profile for basic profiling.
472 Enter a system sleep state until specified wakeup time.
478 The linux32 utility is used to create a 32bit environment for the
479 specified program (usually a shell). It only makes sense to have
480 this util on a system that supports both 64bit and 32bit userland
481 (like amd64/x86, ppc64/ppc, sparc64/sparc, etc...).
487 This option enables both the 'swapon' and the 'swapoff' utilities.
488 Once you have created some swap space using 'mkswap', you also need
489 to enable your swap space with the 'swapon' utility. The 'swapoff'
490 utility is used, typically at system shutdown, to disable any swap
491 space. If you are not using any swap space, you can leave this
498 The switch_root utility is used from initramfs to select a new
499 root device. Under initramfs, you have to use this instead of
500 pivot_root. (Stop reading here if you don't care why.)
502 Booting with initramfs extracts a gzipped cpio archive into rootfs
503 (which is a variant of ramfs/tmpfs). Because rootfs can't be moved
504 or unmounted*, pivot_root will not work from initramfs. Instead,
505 switch_root deletes everything out of rootfs (including itself),
506 does a mount --move that overmounts rootfs with the new root, and
507 then execs the specified init program.
509 * Because the Linux kernel uses rootfs internally as the starting
510 and ending point for searching through the kernel's doubly linked
511 list of active mount points. That's why.
517 When you want to remove a mounted filesystem from its current mount point,
518 for example when you are shutting down the system, the 'umount' utility is
519 the tool to use. If you enabled the 'mount' utility, you almost certainly
520 also want to enable 'umount'.
522 config FEATURE_UMOUNT_ALL
523 bool "umount -a option"
527 Support -a option to unmount all currently mounted filesystems.
529 comment "Common options for mount/umount"
530 depends on MOUNT || UMOUNT
532 config FEATURE_MOUNT_LOOP
533 bool "Support loopback mounts"
535 depends on MOUNT || UMOUNT
537 Enabling this feature allows automatic mounting of files (containing
538 filesystem images) via the linux kernel's loopback devices. The mount
539 command will detect you are trying to mount a file instead of a block
540 device, and transparently associate the file with a loopback device.
541 The umount command will also free that loopback device.
543 You can still use the 'losetup' utility (to manually associate files
544 with loop devices) if you need to do something advanced, such as
545 specify an offset or cryptographic options to the loopback device.
546 (If you don't want umount to free the loop device, use "umount -D".)
548 config FEATURE_MTAB_SUPPORT
549 bool "Support for the old /etc/mtab file"
551 depends on MOUNT || UMOUNT
552 select FEATURE_MOUNT_FAKE
554 Historically, Unix systems kept track of the currently mounted
555 partitions in the file "/etc/mtab". These days, the kernel exports
556 the list of currently mounted partitions in "/proc/mounts", rendering
557 the old mtab file obsolete. (In modern systems, /etc/mtab should be
558 a symlink to /proc/mounts.)
560 The only reason to have mount maintain an /etc/mtab file itself is if
561 your stripped-down embedded system does not have a /proc directory.
562 If you must use this, keep in mind it's inherently brittle (for
563 example a mount under chroot won't update it), can't handle modern
564 features like separate per-process filesystem namespaces, requires
565 that your /etc directory be writeable, tends to get easily confused
566 by --bind or --move mounts, won't update if you rename a directory
567 that contains a mount point, and so on. (In brief: avoid.)
569 About the only reason to use this is if you've removed /proc from