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_INSTALLER
182 bool "Support --install [-s] to install applet links at runtime"
186 Enable 'busybox --install [-s]' support. This will allow you to use
187 busybox at runtime to create hard links or symlinks for all the
188 applets that are compiled into busybox.
190 config INSTALL_NO_USR
191 bool "Don't use /usr"
194 Disable use of /usr. "busybox --install" and "make install"
195 will install applets only to /bin and /sbin,
196 never to /usr/bin or /usr/sbin.
199 bool "Drop SUID state for most applets"
202 With this option you can install the busybox binary belonging
203 to root with the suid bit set, enabling some applets to perform
204 root-level operations even when run by ordinary users
205 (for example, mounting of user mounts in fstab needs this).
207 With this option enabled, busybox drops privileges for applets
208 that don't need root access, before entering their main() function.
210 If you are really paranoid and don't want even initial busybox code
211 to run under root for every applet, build two busybox binaries with
212 different applets in them (and the appropriate symlinks pointing
213 to each binary), and only set the suid bit on the one that needs it.
215 Some applets which require root rights (need suid bit on the binary
216 or to be run by root) and will refuse to execute otherwise:
217 crontab, login, passwd, su, vlock, wall.
219 The applets which will use root rights if they have them
220 (via suid bit, or because run by root), but would try to work
221 without root right nevertheless:
222 findfs, ping[6], traceroute[6], mount.
224 Note that if you DO NOT select this option, but DO make busybox
225 suid root, ALL applets will run under root, which is a huge
226 security hole (think "cp /some/file /etc/passwd").
228 config FEATURE_SUID_CONFIG
229 bool "Enable SUID configuration via /etc/busybox.conf"
231 depends on FEATURE_SUID
233 Allow the SUID/SGID state of an applet to be determined at runtime
234 by checking /etc/busybox.conf. (This is sort of a poor man's sudo.)
235 The format of this file is as follows:
237 APPLET = [Ssx-][Ssx-][x-] [USER.GROUP]
239 s: USER or GROUP is allowed to execute APPLET.
240 APPLET will run under USER or GROUP
241 (regardless of who's running it).
242 S: USER or GROUP is NOT allowed to execute APPLET.
243 APPLET will run under USER or GROUP.
244 This option is not very sensical.
245 x: USER/GROUP/others are allowed to execute APPLET.
246 No UID/GID change will be done when it is run.
247 -: USER/GROUP/others are not allowed to execute APPLET.
249 An example might help:
252 |su = ssx root.0 # applet su can be run by anyone and runs with
254 |su = ssx # exactly the same
256 |mount = sx- root.disk # applet mount can be run by root and members
257 | # of group disk (but not anyone else)
258 | # and runs with euid=0 (egid is not changed)
260 |cp = --- # disable applet cp for everyone
262 The file has to be owned by user root, group root and has to be
263 writeable only by root:
264 (chown 0.0 /etc/busybox.conf; chmod 600 /etc/busybox.conf)
265 The busybox executable has to be owned by user root, group
266 root and has to be setuid root for this to work:
267 (chown 0.0 /bin/busybox; chmod 4755 /bin/busybox)
269 Robert 'sandman' Griebl has more information here:
270 <url: http://www.softforge.de/bb/suid.html >.
272 config FEATURE_SUID_CONFIG_QUIET
273 bool "Suppress warning message if /etc/busybox.conf is not readable"
275 depends on FEATURE_SUID_CONFIG
277 /etc/busybox.conf should be readable by the user needing the SUID,
278 check this option to avoid users to be notified about missing
281 config FEATURE_PREFER_APPLETS
282 bool "exec prefers applets"
285 This is an experimental option which directs applets about to
286 call 'exec' to try and find an applicable busybox applet before
287 searching the PATH. This is typically done by exec'ing
290 This may affect shell, find -exec, xargs and similar applets.
291 They will use applets even if /bin/APPLET -> busybox link
292 is missing (or is not a link to busybox). However, this causes
293 problems in chroot jails without mounted /proc and with ps/top
294 (command name can be shown as 'exe' for applets started this way).
296 config BUSYBOX_EXEC_PATH
297 string "Path to busybox executable"
298 default "/proc/self/exe"
300 When applets need to run other applets, busybox
301 sometimes needs to exec() itself. When the /proc filesystem is
302 mounted, /proc/self/exe always points to the currently running
303 executable. If you haven't got /proc, set this to wherever you
304 want to run busybox from.
307 bool "Support NSA Security Enhanced Linux"
309 select PLATFORM_LINUX
311 Enable support for SELinux in applets ls, ps, and id. Also provide
312 the option of compiling in SELinux applets.
314 If you do not have a complete SELinux userland installed, this stuff
315 will not compile. Specifially, libselinux 1.28 or better is
316 directly required by busybox. If the installation is located in a
317 non-standard directory, provide it by invoking make as follows:
319 CFLAGS=-I<libselinux-include-path> \
320 LDFLAGS=-L<libselinux-lib-path> \
323 Most people will leave this set to 'N'.
325 config FEATURE_CLEAN_UP
326 bool "Clean up all memory before exiting (usually not needed)"
329 As a size optimization, busybox normally exits without explicitly
330 freeing dynamically allocated memory or closing files. This saves
331 space since the OS will clean up for us, but it can confuse debuggers
332 like valgrind, which report tons of memory and resource leaks.
334 Don't enable this unless you have a really good reason to clean
337 # These are auto-selected by other options
339 config FEATURE_SYSLOG
340 bool #No description makes it a hidden option
343 #This option is auto-selected when you select any applet which may
344 #send its output to syslog. You do not need to select it manually.
346 config PLATFORM_LINUX
347 bool #No description makes it a hidden option
350 #For the most part, busybox requires only POSIX compatibility
351 #from the target system, but some applets and features use
352 #Linux-specific interfaces.
354 #This is automatically selected if any applet or feature requires
355 #Linux-specific interfaces. You do not need to select it manually.
357 comment 'Build Options'
360 bool "Build static binary (no shared libs)"
363 If you want to build a static binary, which does not use
364 or require any shared libraries, enable this option.
365 Static binaries are larger, but do not require functioning
366 dynamic libraries to be present, which is important if used
367 as a system rescue tool.
370 bool "Build position independent executable"
374 Hardened code option. PIE binaries are loaded at a different
375 address at each invocation. This has some overhead,
376 particularly on x86-32 which is short on registers.
378 Most people will leave this set to 'N'.
381 bool "Force NOMMU build"
384 Busybox tries to detect whether architecture it is being
385 built against supports MMU or not. If this detection fails,
386 or if you want to build NOMMU version of busybox for testing,
387 you may force NOMMU build here.
389 Most people will leave this set to 'N'.
391 # PIE can be made to work with BUILD_LIBBUSYBOX, but currently
392 # build system does not support that
393 config BUILD_LIBBUSYBOX
394 bool "Build shared libbusybox"
396 depends on !FEATURE_PREFER_APPLETS && !PIE && !STATIC
398 Build a shared library libbusybox.so.N.N.N which contains all
401 This feature allows every applet to be built as a really tiny
402 separate executable linked against the library:
404 | text data bss dec hex filename
405 | 939 212 28 1179 49b 0_lib/last
406 | 939 212 28 1179 49b 0_lib/less
407 | 919138 8328 1556 929022 e2cfe 0_lib/libbusybox.so.1.N.M
409 This is useful on NOMMU systems which are not capable
410 of sharing executables, but are capable of sharing code
411 in dynamic libraries.
413 config FEATURE_LIBBUSYBOX_STATIC
414 bool "Pull in all external references into libbusybox"
416 depends on BUILD_LIBBUSYBOX
418 Make libbusybox library independent, not using or requiring
419 any other shared libraries.
421 config FEATURE_INDIVIDUAL
422 bool "Produce a binary for each applet, linked against libbusybox"
424 depends on BUILD_LIBBUSYBOX
426 If your CPU architecture doesn't allow for sharing text/rodata
427 sections of running binaries, but allows for runtime dynamic
428 libraries, this option will allow you to reduce memory footprint
429 when you have many different applets running at once.
431 If your CPU architecture allows for sharing text/rodata,
432 having single binary is more optimal.
434 Each applet will be a tiny program, dynamically linked
435 against libbusybox.so.N.N.N.
437 You need to have a working dynamic linker.
439 config FEATURE_SHARED_BUSYBOX
440 bool "Produce additional busybox binary linked against libbusybox"
442 depends on BUILD_LIBBUSYBOX
444 Build busybox, dynamically linked against libbusybox.so.N.N.N.
446 You need to have a working dynamic linker.
448 ### config BUILD_AT_ONCE
449 ### bool "Compile all sources at once"
452 ### Normally each source-file is compiled with one invocation of
454 ### If you set this option, all sources are compiled at once.
455 ### This gives the compiler more opportunities to optimize which can
456 ### result in smaller and/or faster binaries.
458 ### Setting this option will consume alot of memory, e.g. if you
459 ### enable all applets with all features, gcc uses more than 300MB
460 ### RAM during compilation of busybox.
462 ### This option is most likely only beneficial for newer compilers
463 ### such as gcc-4.1 and above.
465 ### Say 'N' unless you know what you are doing.
467 config CROSS_COMPILER_PREFIX
468 string "Cross compiler prefix"
471 If you want to build busybox with a cross compiler, then you
472 will need to set this to the cross-compiler prefix, for example,
475 Note that CROSS_COMPILE environment variable or
476 "make CROSS_COMPILE=xxx ..." will override this selection.
478 Native builds leave this empty.
481 string "Path to sysroot"
484 If you want to build busybox with a cross compiler, then you
485 might also need to specify where /usr/include and /usr/lib
488 For example, busybox can be built against an installed
489 Android NDK, platform version 9, for ARM ABI with
491 CONFIG_SYSROOT=/opt/android-ndk/platforms/android-9/arch-arm
493 Native builds leave this empty.
496 string "Additional CFLAGS"
499 Additional CFLAGS to pass to the compiler verbatim.
502 string "Additional LDFLAGS"
505 Additional LDFLAGS to pass to the linker verbatim.
508 string "Additional LDLIBS"
511 Additional LDLIBS to pass to the linker with -l.
513 config USE_PORTABLE_CODE
514 bool "Avoid using GCC-specific code constructs"
517 Use this option if you are trying to compile busybox with
518 compiler other than gcc.
519 If you do use gcc, this option may needlessly increase code size.
521 config STACK_OPTIMIZATION_386
522 bool "Use -mpreferred-stack-boundary=2 on i386 arch"
525 This option makes for smaller code, but some libc versions
526 do not work with it (they use SSE instructions without
527 ensuring stack alignment).
529 comment 'Installation Options ("make install" behavior)'
532 prompt "What kind of applet links to install"
533 default INSTALL_APPLET_SYMLINKS
535 Choose what kind of links to applets are created by "make install".
537 config INSTALL_APPLET_SYMLINKS
540 Install applets as soft-links to the busybox binary. This needs some
541 free inodes on the filesystem, but might help with filesystem
542 generators that can't cope with hard-links.
544 config INSTALL_APPLET_HARDLINKS
547 Install applets as hard-links to the busybox binary. This might
548 count on a filesystem with few inodes.
550 config INSTALL_APPLET_SCRIPT_WRAPPERS
551 bool "as script wrappers"
553 Install applets as script wrappers that call the busybox binary.
555 config INSTALL_APPLET_DONT
558 Do not install applet links. Useful when you plan to use
559 busybox --install for installing links, or plan to use
560 a standalone shell and thus don't need applet links.
565 prompt "/bin/sh applet link"
566 default INSTALL_SH_APPLET_SYMLINK
567 depends on INSTALL_APPLET_SCRIPT_WRAPPERS
569 Choose how you install /bin/sh applet link.
571 config INSTALL_SH_APPLET_SYMLINK
574 Install /bin/sh applet as soft-link to the busybox binary.
576 config INSTALL_SH_APPLET_HARDLINK
579 Install /bin/sh applet as hard-link to the busybox binary.
581 config INSTALL_SH_APPLET_SCRIPT_WRAPPER
582 bool "as script wrapper"
584 Install /bin/sh applet as script wrapper that calls
590 string "Destination path for 'make install'"
593 Where "make install" should install busybox binary and links.
595 comment 'Debugging Options'
598 bool "Build with debug information"
601 Say Y here to compile with debug information.
602 This increases the size of the binary considerably, and
603 should only be used when doing development.
605 This adds -g option to gcc command line.
607 Most people should answer N.
609 config DEBUG_PESSIMIZE
610 bool "Disable compiler optimizations"
614 The compiler's optimization of source code can eliminate and reorder
615 code, resulting in an executable that's hard to understand when
616 stepping through it with a debugger. This switches it off, resulting
617 in a much bigger executable that more closely matches the source
620 This replaces -Os/-O2 with -O0 in gcc command line.
622 config DEBUG_SANITIZE
623 bool "Enable runtime sanitizers (ASAN/LSAN/USAN/etc...)"
626 Say Y here if you want to enable runtime sanitizers. These help
627 catch bad memory accesses (e.g. buffer overflows), but will make
628 the executable larger and slow down runtime a bit.
630 This adds -fsanitize=foo options to gcc command line.
632 If you aren't developing/testing busybox, say N here.
635 bool "Build unit tests"
638 Say Y here if you want to build unit tests (both the framework and
639 test cases) as an applet. This results in bigger code, so you
640 probably don't want this option in production builds.
643 bool "Abort compilation on any warning"
646 This adds -Werror to gcc command line.
648 Most people should answer N.
651 prompt "Additional debugging library"
654 Using an additional debugging library will make busybox become
655 considerably larger and will cause it to run more slowly. You
656 should always leave this option disabled for production use.
660 This enables compiling with dmalloc ( http://dmalloc.com/ )
661 which is an excellent public domain mem leak and malloc problem
662 detector. To enable dmalloc, before running busybox you will
663 want to properly set your environment, for example:
664 export DMALLOC_OPTIONS=debug=0x34f47d83,inter=100,log=logfile
665 The 'debug=' value is generated using the following command
666 dmalloc -p log-stats -p log-non-free -p log-bad-space \
667 -p log-elapsed-time -p check-fence -p check-heap \
668 -p check-lists -p check-blank -p check-funcs -p realloc-copy \
671 Electric-fence support:
672 -----------------------
673 This enables compiling with Electric-fence support. Electric
674 fence is another very useful malloc debugging library which uses
675 your computer's virtual memory hardware to detect illegal memory
676 accesses. This support will make busybox be considerably larger
677 and run slower, so you should leave this option disabled unless
678 you are hunting a hard to find memory problem.
688 bool "Electric-fence"
692 source libbb/Config.in
698 source archival/Config.in
699 source coreutils/Config.in
700 source console-tools/Config.in
701 source debianutils/Config.in
702 source klibc-utils/Config.in
703 source editors/Config.in
704 source findutils/Config.in
705 source init/Config.in
706 source loginutils/Config.in
707 source e2fsprogs/Config.in
708 source modutils/Config.in
709 source util-linux/Config.in
710 source miscutils/Config.in
711 source networking/Config.in
712 source printutils/Config.in
713 source mailutils/Config.in
714 source procps/Config.in
715 source runit/Config.in
716 source selinux/Config.in
717 source shell/Config.in
718 source sysklogd/Config.in