2 # For a description of the syntax of this configuration file,
3 # see docs/Kconfig-language.txt.
6 mainmenu "Configuration"
15 bool "Enable compatibility for full-blown desktop systems"
18 Enable applet options and features which are not essential.
19 Many applet options have dedicated config options to (de)select them
20 under that applet; this options enables those options which have no
21 individual config item for them.
23 Select this if you plan to use busybox on full-blown desktop machine
24 with common Linux distro, which needs higher level of command-line
27 If you are preparing your build to be used on an embedded box
28 where you have tighter control over the entire set of userspace
29 tools, you can unselect this option for smaller code size.
32 bool "Provide compatible behavior for rare corner cases (bigger code)"
35 This option makes grep, sed etc handle rare corner cases
36 (embedded NUL bytes and such). This makes code bigger and uses
37 some GNU extensions in libc. You probably only need this option
38 if you plan to run busybox on desktop.
41 bool "Building for Fedora distribution"
44 This option makes some tools behave like they do on Fedora.
46 At the time of this writing (2017-08) this only affects uname:
47 normally, uname -p (processor) and uname -i (platform)
48 are shown as "unknown", but with this option uname -p
49 shows the same string as uname -m (machine type),
50 and so does uname -i unless machine type is i486/i586/i686 -
51 then uname -i shows "i386".
54 bool "Enable obsolete features removed before SUSv3"
57 This option will enable backwards compatibility with SuSv2,
58 specifically, old-style numeric options ('command -1 <file>')
59 will be supported in head, tail, and fold. (Note: should
63 bool "Support --long-options"
66 Enable this if you want busybox applets to use the gnu --long-option
67 style, in addition to single character -a -b -c style options.
70 bool "Show applet usage messages"
73 Enabling this option, applets will show terse help messages
74 when invoked with wrong arguments.
75 If you do not want to show any (helpful) usage message when
76 issuing wrong command syntax, you can say 'N' here,
77 saving approximately 7k.
79 config FEATURE_VERBOSE_USAGE
80 bool "Show verbose applet usage messages"
84 All applets will show verbose help messages when invoked with --help.
85 This will add a lot of text to the binary.
87 config FEATURE_COMPRESS_USAGE
88 bool "Store applet usage messages in compressed form"
92 Store usage messages in .bz2 compressed form, uncompress them
93 on-the-fly when "APPLET --help" is run.
95 If you have a really tiny busybox with few applets enabled (and
96 bunzip2 isn't one of them), the overhead of the decompressor might
97 be noticeable. Also, if you run executables directly from ROM
98 and have very little memory, this might not be a win. Otherwise,
99 you probably want this.
102 bool "Support files > 2 GB"
105 If you need to work with large files, enable this option.
106 This will have no effect if your kernel or your C
107 library lacks large file support for large files. Some of the
108 programs that can benefit from large file support include dd, gzip,
112 bool "Support PAM (Pluggable Authentication Modules)"
115 Use PAM in some applets (currently login and httpd) instead
116 of direct access to password database.
118 config FEATURE_DEVPTS
119 bool "Use the devpts filesystem for Unix98 PTYs"
122 Enable if you want to use Unix98 PTY support. If enabled,
123 busybox will use /dev/ptmx for the master side of the pseudoterminal
124 and /dev/pts/<number> for the slave side. Otherwise, BSD style
125 /dev/ttyp<number> will be used. To use this option, you should have
129 bool "Support utmp file"
132 The file /var/run/utmp is used to track who is currently logged in.
133 With this option on, certain applets (getty, login, telnetd etc)
134 will create and delete entries there.
135 "who" applet requires this option.
138 bool "Support wtmp file"
140 depends on FEATURE_UTMP
142 The file /var/run/wtmp is used to track when users have logged into
143 and logged out of the system.
144 With this option on, certain applets (getty, login, telnetd etc)
145 will append new entries there.
146 "last" applet requires this option.
148 config FEATURE_PIDFILE
149 bool "Support writing pidfiles"
152 This option makes some applets (e.g. crond, syslogd, inetd) write
153 a pidfile at the configured PID_FILE_PATH. It has no effect
154 on applets which require pidfiles to run.
157 string "Directory for pidfiles"
159 depends on FEATURE_PIDFILE
161 This is the default path where pidfiles are created. Applets which
162 allow you to set the pidfile path on the command line will override
163 this value. The option has no effect on applets that require you to
164 specify a pidfile path.
167 bool "Include busybox applet"
170 The busybox applet provides general help message and allows
171 the included applets to be listed. It also provides
172 optional --install command to create applet links. If you unselect
173 this option, running busybox without any arguments will give
174 just a cryptic error message:
177 busybox: applet not found
179 Running "busybox APPLET [ARGS...]" will still work, of course.
181 config FEATURE_SHOW_SCRIPT
182 bool "Support --show SCRIPT"
186 config FEATURE_INSTALLER
187 bool "Support --install [-s] to install applet links at runtime"
191 Enable 'busybox --install [-s]' support. This will allow you to use
192 busybox at runtime to create hard links or symlinks for all the
193 applets that are compiled into busybox.
195 config INSTALL_NO_USR
196 bool "Don't use /usr"
199 Disable use of /usr. "busybox --install" and "make install"
200 will install applets only to /bin and /sbin,
201 never to /usr/bin or /usr/sbin.
204 bool "Drop SUID state for most applets"
207 With this option you can install the busybox binary belonging
208 to root with the suid bit set, enabling some applets to perform
209 root-level operations even when run by ordinary users
210 (for example, mounting of user mounts in fstab needs this).
212 With this option enabled, busybox drops privileges for applets
213 that don't need root access, before entering their main() function.
215 If you are really paranoid and don't want even initial busybox code
216 to run under root for every applet, build two busybox binaries with
217 different applets in them (and the appropriate symlinks pointing
218 to each binary), and only set the suid bit on the one that needs it.
220 Some applets which require root rights (need suid bit on the binary
221 or to be run by root) and will refuse to execute otherwise:
222 crontab, login, passwd, su, vlock, wall.
224 The applets which will use root rights if they have them
225 (via suid bit, or because run by root), but would try to work
226 without root right nevertheless:
227 findfs, ping[6], traceroute[6], mount.
229 Note that if you DO NOT select this option, but DO make busybox
230 suid root, ALL applets will run under root, which is a huge
231 security hole (think "cp /some/file /etc/passwd").
233 config FEATURE_SUID_CONFIG
234 bool "Enable SUID configuration via /etc/busybox.conf"
236 depends on FEATURE_SUID
238 Allow the SUID/SGID state of an applet to be determined at runtime
239 by checking /etc/busybox.conf. (This is sort of a poor man's sudo.)
240 The format of this file is as follows:
242 APPLET = [Ssx-][Ssx-][x-] [USER.GROUP]
244 s: USER or GROUP is allowed to execute APPLET.
245 APPLET will run under USER or GROUP
246 (regardless of who's running it).
247 S: USER or GROUP is NOT allowed to execute APPLET.
248 APPLET will run under USER or GROUP.
249 This option is not very sensical.
250 x: USER/GROUP/others are allowed to execute APPLET.
251 No UID/GID change will be done when it is run.
252 -: USER/GROUP/others are not allowed to execute APPLET.
254 An example might help:
257 |su = ssx root.0 # applet su can be run by anyone and runs with
259 |su = ssx # exactly the same
261 |mount = sx- root.disk # applet mount can be run by root and members
262 | # of group disk (but not anyone else)
263 | # and runs with euid=0 (egid is not changed)
265 |cp = --- # disable applet cp for everyone
267 The file has to be owned by user root, group root and has to be
268 writeable only by root:
269 (chown 0.0 /etc/busybox.conf; chmod 600 /etc/busybox.conf)
270 The busybox executable has to be owned by user root, group
271 root and has to be setuid root for this to work:
272 (chown 0.0 /bin/busybox; chmod 4755 /bin/busybox)
274 Robert 'sandman' Griebl has more information here:
275 <url: http://www.softforge.de/bb/suid.html >.
277 config FEATURE_SUID_CONFIG_QUIET
278 bool "Suppress warning message if /etc/busybox.conf is not readable"
280 depends on FEATURE_SUID_CONFIG
282 /etc/busybox.conf should be readable by the user needing the SUID,
283 check this option to avoid users to be notified about missing
286 config FEATURE_PREFER_APPLETS
287 bool "exec prefers applets"
290 This is an experimental option which directs applets about to
291 call 'exec' to try and find an applicable busybox applet before
292 searching the PATH. This is typically done by exec'ing
295 This may affect shell, find -exec, xargs and similar applets.
296 They will use applets even if /bin/APPLET -> busybox link
297 is missing (or is not a link to busybox). However, this causes
298 problems in chroot jails without mounted /proc and with ps/top
299 (command name can be shown as 'exe' for applets started this way).
301 config BUSYBOX_EXEC_PATH
302 string "Path to busybox executable"
303 default "/proc/self/exe"
305 When applets need to run other applets, busybox
306 sometimes needs to exec() itself. When the /proc filesystem is
307 mounted, /proc/self/exe always points to the currently running
308 executable. If you haven't got /proc, set this to wherever you
309 want to run busybox from.
312 bool "Support NSA Security Enhanced Linux"
314 select PLATFORM_LINUX
316 Enable support for SELinux in applets ls, ps, and id. Also provide
317 the option of compiling in SELinux applets.
319 If you do not have a complete SELinux userland installed, this stuff
320 will not compile. Specifially, libselinux 1.28 or better is
321 directly required by busybox. If the installation is located in a
322 non-standard directory, provide it by invoking make as follows:
324 CFLAGS=-I<libselinux-include-path> \
325 LDFLAGS=-L<libselinux-lib-path> \
328 Most people will leave this set to 'N'.
330 config FEATURE_CLEAN_UP
331 bool "Clean up all memory before exiting (usually not needed)"
334 As a size optimization, busybox normally exits without explicitly
335 freeing dynamically allocated memory or closing files. This saves
336 space since the OS will clean up for us, but it can confuse debuggers
337 like valgrind, which report tons of memory and resource leaks.
339 Don't enable this unless you have a really good reason to clean
342 # These are auto-selected by other options
344 config FEATURE_SYSLOG
345 bool #No description makes it a hidden option
348 #This option is auto-selected when you select any applet which may
349 #send its output to syslog. You do not need to select it manually.
351 config PLATFORM_LINUX
352 bool #No description makes it a hidden option
355 #For the most part, busybox requires only POSIX compatibility
356 #from the target system, but some applets and features use
357 #Linux-specific interfaces.
359 #This is automatically selected if any applet or feature requires
360 #Linux-specific interfaces. You do not need to select it manually.
362 comment 'Build Options'
365 bool "Build static binary (no shared libs)"
368 If you want to build a static binary, which does not use
369 or require any shared libraries, enable this option.
370 Static binaries are larger, but do not require functioning
371 dynamic libraries to be present, which is important if used
372 as a system rescue tool.
375 bool "Build position independent executable"
379 Hardened code option. PIE binaries are loaded at a different
380 address at each invocation. This has some overhead,
381 particularly on x86-32 which is short on registers.
383 Most people will leave this set to 'N'.
386 bool "Force NOMMU build"
389 Busybox tries to detect whether architecture it is being
390 built against supports MMU or not. If this detection fails,
391 or if you want to build NOMMU version of busybox for testing,
392 you may force NOMMU build here.
394 Most people will leave this set to 'N'.
396 # PIE can be made to work with BUILD_LIBBUSYBOX, but currently
397 # build system does not support that
398 config BUILD_LIBBUSYBOX
399 bool "Build shared libbusybox"
401 depends on !FEATURE_PREFER_APPLETS && !PIE && !STATIC
403 Build a shared library libbusybox.so.N.N.N which contains all
406 This feature allows every applet to be built as a really tiny
407 separate executable linked against the library:
409 | text data bss dec hex filename
410 | 939 212 28 1179 49b 0_lib/last
411 | 939 212 28 1179 49b 0_lib/less
412 | 919138 8328 1556 929022 e2cfe 0_lib/libbusybox.so.1.N.M
414 This is useful on NOMMU systems which are not capable
415 of sharing executables, but are capable of sharing code
416 in dynamic libraries.
418 config FEATURE_LIBBUSYBOX_STATIC
419 bool "Pull in all external references into libbusybox"
421 depends on BUILD_LIBBUSYBOX
423 Make libbusybox library independent, not using or requiring
424 any other shared libraries.
426 config FEATURE_INDIVIDUAL
427 bool "Produce a binary for each applet, linked against libbusybox"
429 depends on BUILD_LIBBUSYBOX
431 If your CPU architecture doesn't allow for sharing text/rodata
432 sections of running binaries, but allows for runtime dynamic
433 libraries, this option will allow you to reduce memory footprint
434 when you have many different applets running at once.
436 If your CPU architecture allows for sharing text/rodata,
437 having single binary is more optimal.
439 Each applet will be a tiny program, dynamically linked
440 against libbusybox.so.N.N.N.
442 You need to have a working dynamic linker.
444 config FEATURE_SHARED_BUSYBOX
445 bool "Produce additional busybox binary linked against libbusybox"
447 depends on BUILD_LIBBUSYBOX
449 Build busybox, dynamically linked against libbusybox.so.N.N.N.
451 You need to have a working dynamic linker.
453 ### config BUILD_AT_ONCE
454 ### bool "Compile all sources at once"
457 ### Normally each source-file is compiled with one invocation of
459 ### If you set this option, all sources are compiled at once.
460 ### This gives the compiler more opportunities to optimize which can
461 ### result in smaller and/or faster binaries.
463 ### Setting this option will consume alot of memory, e.g. if you
464 ### enable all applets with all features, gcc uses more than 300MB
465 ### RAM during compilation of busybox.
467 ### This option is most likely only beneficial for newer compilers
468 ### such as gcc-4.1 and above.
470 ### Say 'N' unless you know what you are doing.
472 config CROSS_COMPILER_PREFIX
473 string "Cross compiler prefix"
476 If you want to build busybox with a cross compiler, then you
477 will need to set this to the cross-compiler prefix, for example,
480 Note that CROSS_COMPILE environment variable or
481 "make CROSS_COMPILE=xxx ..." will override this selection.
483 Native builds leave this empty.
486 string "Path to sysroot"
489 If you want to build busybox with a cross compiler, then you
490 might also need to specify where /usr/include and /usr/lib
493 For example, busybox can be built against an installed
494 Android NDK, platform version 9, for ARM ABI with
496 CONFIG_SYSROOT=/opt/android-ndk/platforms/android-9/arch-arm
498 Native builds leave this empty.
501 string "Additional CFLAGS"
504 Additional CFLAGS to pass to the compiler verbatim.
507 string "Additional LDFLAGS"
510 Additional LDFLAGS to pass to the linker verbatim.
513 string "Additional LDLIBS"
516 Additional LDLIBS to pass to the linker with -l.
518 config USE_PORTABLE_CODE
519 bool "Avoid using GCC-specific code constructs"
522 Use this option if you are trying to compile busybox with
523 compiler other than gcc.
524 If you do use gcc, this option may needlessly increase code size.
526 config STACK_OPTIMIZATION_386
527 bool "Use -mpreferred-stack-boundary=2 on i386 arch"
530 This option makes for smaller code, but some libc versions
531 do not work with it (they use SSE instructions without
532 ensuring stack alignment).
534 comment 'Installation Options ("make install" behavior)'
537 prompt "What kind of applet links to install"
538 default INSTALL_APPLET_SYMLINKS
540 Choose what kind of links to applets are created by "make install".
542 config INSTALL_APPLET_SYMLINKS
545 Install applets as soft-links to the busybox binary. This needs some
546 free inodes on the filesystem, but might help with filesystem
547 generators that can't cope with hard-links.
549 config INSTALL_APPLET_HARDLINKS
552 Install applets as hard-links to the busybox binary. This might
553 count on a filesystem with few inodes.
555 config INSTALL_APPLET_SCRIPT_WRAPPERS
556 bool "as script wrappers"
558 Install applets as script wrappers that call the busybox binary.
560 config INSTALL_APPLET_DONT
563 Do not install applet links. Useful when you plan to use
564 busybox --install for installing links, or plan to use
565 a standalone shell and thus don't need applet links.
570 prompt "/bin/sh applet link"
571 default INSTALL_SH_APPLET_SYMLINK
572 depends on INSTALL_APPLET_SCRIPT_WRAPPERS
574 Choose how you install /bin/sh applet link.
576 config INSTALL_SH_APPLET_SYMLINK
579 Install /bin/sh applet as soft-link to the busybox binary.
581 config INSTALL_SH_APPLET_HARDLINK
584 Install /bin/sh applet as hard-link to the busybox binary.
586 config INSTALL_SH_APPLET_SCRIPT_WRAPPER
587 bool "as script wrapper"
589 Install /bin/sh applet as script wrapper that calls
595 string "Destination path for 'make install'"
598 Where "make install" should install busybox binary and links.
600 comment 'Debugging Options'
603 bool "Build with debug information"
606 Say Y here to compile with debug information.
607 This increases the size of the binary considerably, and
608 should only be used when doing development.
610 This adds -g option to gcc command line.
612 Most people should answer N.
614 config DEBUG_PESSIMIZE
615 bool "Disable compiler optimizations"
619 The compiler's optimization of source code can eliminate and reorder
620 code, resulting in an executable that's hard to understand when
621 stepping through it with a debugger. This switches it off, resulting
622 in a much bigger executable that more closely matches the source
625 This replaces -Os/-O2 with -O0 in gcc command line.
627 config DEBUG_SANITIZE
628 bool "Enable runtime sanitizers (ASAN/LSAN/USAN/etc...)"
631 Say Y here if you want to enable runtime sanitizers. These help
632 catch bad memory accesses (e.g. buffer overflows), but will make
633 the executable larger and slow down runtime a bit.
635 This adds -fsanitize=foo options to gcc command line.
637 If you aren't developing/testing busybox, say N here.
640 bool "Build unit tests"
643 Say Y here if you want to build unit tests (both the framework and
644 test cases) as an applet. This results in bigger code, so you
645 probably don't want this option in production builds.
648 bool "Abort compilation on any warning"
651 This adds -Werror to gcc command line.
653 Most people should answer N.
656 prompt "Additional debugging library"
659 Using an additional debugging library will make busybox become
660 considerably larger and will cause it to run more slowly. You
661 should always leave this option disabled for production use.
665 This enables compiling with dmalloc ( http://dmalloc.com/ )
666 which is an excellent public domain mem leak and malloc problem
667 detector. To enable dmalloc, before running busybox you will
668 want to properly set your environment, for example:
669 export DMALLOC_OPTIONS=debug=0x34f47d83,inter=100,log=logfile
670 The 'debug=' value is generated using the following command
671 dmalloc -p log-stats -p log-non-free -p log-bad-space \
672 -p log-elapsed-time -p check-fence -p check-heap \
673 -p check-lists -p check-blank -p check-funcs -p realloc-copy \
676 Electric-fence support:
677 -----------------------
678 This enables compiling with Electric-fence support. Electric
679 fence is another very useful malloc debugging library which uses
680 your computer's virtual memory hardware to detect illegal memory
681 accesses. This support will make busybox be considerably larger
682 and run slower, so you should leave this option disabled unless
683 you are hunting a hard to find memory problem.
693 bool "Electric-fence"
697 source libbb/Config.in
703 source archival/Config.in
704 source coreutils/Config.in
705 source console-tools/Config.in
706 source debianutils/Config.in
707 source klibc-utils/Config.in
708 source editors/Config.in
709 source findutils/Config.in
710 source init/Config.in
711 source loginutils/Config.in
712 source e2fsprogs/Config.in
713 source modutils/Config.in
714 source util-linux/Config.in
715 source miscutils/Config.in
716 source networking/Config.in
717 source printutils/Config.in
718 source mailutils/Config.in
719 source procps/Config.in
720 source runit/Config.in
721 source selinux/Config.in
722 source shell/Config.in
723 source sysklogd/Config.in