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 (8kb)"
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 || FEATURE_CROND_SPECIAL_TIMES
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. When crond has the 'Support special times'
165 option enabled, the 'crond.reboot' file is also stored here.
168 bool "Include busybox applet"
171 The busybox applet provides general help message and allows
172 the included applets to be listed. It also provides
173 optional --install command to create applet links. If you unselect
174 this option, running busybox without any arguments will give
175 just a cryptic error message:
178 busybox: applet not found
180 Running "busybox APPLET [ARGS...]" will still work, of course.
182 config FEATURE_SHOW_SCRIPT
183 bool "Support --show SCRIPT"
187 config FEATURE_INSTALLER
188 bool "Support --install [-s] to install applet links at runtime"
192 Enable 'busybox --install [-s]' support. This will allow you to use
193 busybox at runtime to create hard links or symlinks for all the
194 applets that are compiled into busybox.
196 config INSTALL_NO_USR
197 bool "Don't use /usr"
200 Disable use of /usr. "busybox --install" and "make install"
201 will install applets only to /bin and /sbin,
202 never to /usr/bin or /usr/sbin.
205 bool "Drop SUID state for most applets"
208 With this option you can install the busybox binary belonging
209 to root with the suid bit set, enabling some applets to perform
210 root-level operations even when run by ordinary users
211 (for example, mounting of user mounts in fstab needs this).
213 With this option enabled, busybox drops privileges for applets
214 that don't need root access, before entering their main() function.
216 If you are really paranoid and don't want even initial busybox code
217 to run under root for every applet, build two busybox binaries with
218 different applets in them (and the appropriate symlinks pointing
219 to each binary), and only set the suid bit on the one that needs it.
221 Some applets which require root rights (need suid bit on the binary
222 or to be run by root) and will refuse to execute otherwise:
223 crontab, login, passwd, su, vlock, wall.
225 The applets which will use root rights if they have them
226 (via suid bit, or because run by root), but would try to work
227 without root right nevertheless:
228 findfs, ping[6], traceroute[6], mount.
230 Note that if you DO NOT select this option, but DO make busybox
231 suid root, ALL applets will run under root, which is a huge
232 security hole (think "cp /some/file /etc/passwd").
234 config FEATURE_SUID_CONFIG
235 bool "Enable SUID configuration via /etc/busybox.conf"
237 depends on FEATURE_SUID
239 Allow the SUID/SGID state of an applet to be determined at runtime
240 by checking /etc/busybox.conf. (This is sort of a poor man's sudo.)
241 The format of this file is as follows:
243 APPLET = [Ssx-][Ssx-][x-] [USER.GROUP]
245 s: USER or GROUP is allowed to execute APPLET.
246 APPLET will run under USER or GROUP
247 (regardless of who's running it).
248 S: USER or GROUP is NOT allowed to execute APPLET.
249 APPLET will run under USER or GROUP.
250 This option is not very sensical.
251 x: USER/GROUP/others are allowed to execute APPLET.
252 No UID/GID change will be done when it is run.
253 -: USER/GROUP/others are not allowed to execute APPLET.
255 An example might help:
258 |su = ssx root.0 # applet su can be run by anyone and runs with
260 |su = ssx # exactly the same
262 |mount = sx- root.disk # applet mount can be run by root and members
263 | # of group disk (but not anyone else)
264 | # and runs with euid=0 (egid is not changed)
266 |cp = --- # disable applet cp for everyone
268 The file has to be owned by user root, group root and has to be
269 writeable only by root:
270 (chown 0.0 /etc/busybox.conf; chmod 600 /etc/busybox.conf)
271 The busybox executable has to be owned by user root, group
272 root and has to be setuid root for this to work:
273 (chown 0.0 /bin/busybox; chmod 4755 /bin/busybox)
275 Robert 'sandman' Griebl has more information here:
276 <url: http://www.softforge.de/bb/suid.html >.
278 config FEATURE_SUID_CONFIG_QUIET
279 bool "Suppress warning message if /etc/busybox.conf is not readable"
281 depends on FEATURE_SUID_CONFIG
283 /etc/busybox.conf should be readable by the user needing the SUID,
284 check this option to avoid users to be notified about missing
287 config FEATURE_PREFER_APPLETS
288 bool "exec prefers applets"
291 This is an experimental option which directs applets about to
292 call 'exec' to try and find an applicable busybox applet before
293 searching the PATH. This is typically done by exec'ing
296 This may affect shell, find -exec, xargs and similar applets.
297 They will use applets even if /bin/APPLET -> busybox link
298 is missing (or is not a link to busybox). However, this causes
299 problems in chroot jails without mounted /proc and with ps/top
300 (command name can be shown as 'exe' for applets started this way).
302 config BUSYBOX_EXEC_PATH
303 string "Path to busybox executable"
304 default "/proc/self/exe"
306 When applets need to run other applets, busybox
307 sometimes needs to exec() itself. When the /proc filesystem is
308 mounted, /proc/self/exe always points to the currently running
309 executable. If you haven't got /proc, set this to wherever you
310 want to run busybox from.
313 bool "Support NSA Security Enhanced Linux"
315 select PLATFORM_LINUX
317 Enable support for SELinux in applets ls, ps, and id. Also provide
318 the option of compiling in SELinux applets.
320 If you do not have a complete SELinux userland installed, this stuff
321 will not compile. Specifially, libselinux 1.28 or better is
322 directly required by busybox. If the installation is located in a
323 non-standard directory, provide it by invoking make as follows:
325 CFLAGS=-I<libselinux-include-path> \
326 LDFLAGS=-L<libselinux-lib-path> \
329 Most people will leave this set to 'N'.
331 config FEATURE_CLEAN_UP
332 bool "Clean up all memory before exiting (usually not needed)"
335 As a size optimization, busybox normally exits without explicitly
336 freeing dynamically allocated memory or closing files. This saves
337 space since the OS will clean up for us, but it can confuse debuggers
338 like valgrind, which report tons of memory and resource leaks.
340 Don't enable this unless you have a really good reason to clean
343 config FEATURE_SYSLOG_INFO
344 bool "Support LOG_INFO level syslog messages"
346 depends on FEATURE_SYSLOG
348 Applets which send their output to syslog use either LOG_INFO or
349 LOG_ERR log levels, but by disabling this option all messages will
350 be logged at the LOG_ERR level, saving just under 200 bytes.
352 # These are auto-selected by other options
354 config FEATURE_SYSLOG
355 bool #No description makes it a hidden option
358 #This option is auto-selected when you select any applet which may
359 #send its output to syslog. You do not need to select it manually.
361 config PLATFORM_LINUX
362 bool #No description makes it a hidden option
365 #For the most part, busybox requires only POSIX compatibility
366 #from the target system, but some applets and features use
367 #Linux-specific interfaces.
369 #This is automatically selected if any applet or feature requires
370 #Linux-specific interfaces. You do not need to select it manually.
372 comment 'Build Options'
375 bool "Build static binary (no shared libs)"
378 If you want to build a static binary, which does not use
379 or require any shared libraries, enable this option.
380 Static binaries are larger, but do not require functioning
381 dynamic libraries to be present, which is important if used
382 as a system rescue tool.
385 bool "Build position independent executable"
389 Hardened code option. PIE binaries are loaded at a different
390 address at each invocation. This has some overhead,
391 particularly on x86-32 which is short on registers.
393 Most people will leave this set to 'N'.
396 bool "Force NOMMU build"
399 Busybox tries to detect whether architecture it is being
400 built against supports MMU or not. If this detection fails,
401 or if you want to build NOMMU version of busybox for testing,
402 you may force NOMMU build here.
404 Most people will leave this set to 'N'.
406 # PIE can be made to work with BUILD_LIBBUSYBOX, but currently
407 # build system does not support that
408 config BUILD_LIBBUSYBOX
409 bool "Build shared libbusybox"
411 depends on !FEATURE_PREFER_APPLETS && !PIE && !STATIC
413 Build a shared library libbusybox.so.N.N.N which contains all
416 This feature allows every applet to be built as a really tiny
417 separate executable linked against the library:
419 | text data bss dec hex filename
420 | 939 212 28 1179 49b 0_lib/last
421 | 939 212 28 1179 49b 0_lib/less
422 | 919138 8328 1556 929022 e2cfe 0_lib/libbusybox.so.1.N.M
424 This is useful on NOMMU systems which are not capable
425 of sharing executables, but are capable of sharing code
426 in dynamic libraries.
428 config FEATURE_LIBBUSYBOX_STATIC
429 bool "Pull in all external references into libbusybox"
431 depends on BUILD_LIBBUSYBOX
433 Make libbusybox library independent, not using or requiring
434 any other shared libraries.
436 config FEATURE_INDIVIDUAL
437 bool "Produce a binary for each applet, linked against libbusybox"
439 depends on BUILD_LIBBUSYBOX
441 If your CPU architecture doesn't allow for sharing text/rodata
442 sections of running binaries, but allows for runtime dynamic
443 libraries, this option will allow you to reduce memory footprint
444 when you have many different applets running at once.
446 If your CPU architecture allows for sharing text/rodata,
447 having single binary is more optimal.
449 Each applet will be a tiny program, dynamically linked
450 against libbusybox.so.N.N.N.
452 You need to have a working dynamic linker.
454 config FEATURE_SHARED_BUSYBOX
455 bool "Produce additional busybox binary linked against libbusybox"
457 depends on BUILD_LIBBUSYBOX
459 Build busybox, dynamically linked against libbusybox.so.N.N.N.
461 You need to have a working dynamic linker.
463 ### config BUILD_AT_ONCE
464 ### bool "Compile all sources at once"
467 ### Normally each source-file is compiled with one invocation of
469 ### If you set this option, all sources are compiled at once.
470 ### This gives the compiler more opportunities to optimize which can
471 ### result in smaller and/or faster binaries.
473 ### Setting this option will consume alot of memory, e.g. if you
474 ### enable all applets with all features, gcc uses more than 300MB
475 ### RAM during compilation of busybox.
477 ### This option is most likely only beneficial for newer compilers
478 ### such as gcc-4.1 and above.
480 ### Say 'N' unless you know what you are doing.
482 config CROSS_COMPILER_PREFIX
483 string "Cross compiler prefix"
486 If you want to build busybox with a cross compiler, then you
487 will need to set this to the cross-compiler prefix, for example,
490 Note that CROSS_COMPILE environment variable or
491 "make CROSS_COMPILE=xxx ..." will override this selection.
493 Native builds leave this empty.
496 string "Path to sysroot"
499 If you want to build busybox with a cross compiler, then you
500 might also need to specify where /usr/include and /usr/lib
503 For example, busybox can be built against an installed
504 Android NDK, platform version 9, for ARM ABI with
506 CONFIG_SYSROOT=/opt/android-ndk/platforms/android-9/arch-arm
508 Native builds leave this empty.
511 string "Additional CFLAGS"
514 Additional CFLAGS to pass to the compiler verbatim.
517 string "Additional LDFLAGS"
520 Additional LDFLAGS to pass to the linker verbatim.
523 string "Additional LDLIBS"
526 Additional LDLIBS to pass to the linker with -l.
528 config USE_PORTABLE_CODE
529 bool "Avoid using GCC-specific code constructs"
532 Use this option if you are trying to compile busybox with
533 compiler other than gcc.
534 If you do use gcc, this option may needlessly increase code size.
536 config STACK_OPTIMIZATION_386
537 bool "Use -mpreferred-stack-boundary=2 on i386 arch"
540 This option makes for smaller code, but some libc versions
541 do not work with it (they use SSE instructions without
542 ensuring stack alignment).
544 comment 'Installation Options ("make install" behavior)'
547 prompt "What kind of applet links to install"
548 default INSTALL_APPLET_SYMLINKS
550 Choose what kind of links to applets are created by "make install".
552 config INSTALL_APPLET_SYMLINKS
555 Install applets as soft-links to the busybox binary. This needs some
556 free inodes on the filesystem, but might help with filesystem
557 generators that can't cope with hard-links.
559 config INSTALL_APPLET_HARDLINKS
562 Install applets as hard-links to the busybox binary. This might
563 count on a filesystem with few inodes.
565 config INSTALL_APPLET_SCRIPT_WRAPPERS
566 bool "as script wrappers"
568 Install applets as script wrappers that call the busybox binary.
570 config INSTALL_APPLET_DONT
573 Do not install applet links. Useful when you plan to use
574 busybox --install for installing links, or plan to use
575 a standalone shell and thus don't need applet links.
580 prompt "/bin/sh applet link"
581 default INSTALL_SH_APPLET_SYMLINK
582 depends on INSTALL_APPLET_SCRIPT_WRAPPERS
584 Choose how you install /bin/sh applet link.
586 config INSTALL_SH_APPLET_SYMLINK
589 Install /bin/sh applet as soft-link to the busybox binary.
591 config INSTALL_SH_APPLET_HARDLINK
594 Install /bin/sh applet as hard-link to the busybox binary.
596 config INSTALL_SH_APPLET_SCRIPT_WRAPPER
597 bool "as script wrapper"
599 Install /bin/sh applet as script wrapper that calls
605 string "Destination path for 'make install'"
608 Where "make install" should install busybox binary and links.
610 comment 'Debugging Options'
613 bool "Build with debug information"
616 Say Y here to compile with debug information.
617 This increases the size of the binary considerably, and
618 should only be used when doing development.
620 This adds -g option to gcc command line.
622 Most people should answer N.
624 config DEBUG_PESSIMIZE
625 bool "Disable compiler optimizations"
629 The compiler's optimization of source code can eliminate and reorder
630 code, resulting in an executable that's hard to understand when
631 stepping through it with a debugger. This switches it off, resulting
632 in a much bigger executable that more closely matches the source
635 This replaces -Os/-O2 with -O0 in gcc command line.
637 config DEBUG_SANITIZE
638 bool "Enable runtime sanitizers (ASAN/LSAN/USAN/etc...)"
641 Say Y here if you want to enable runtime sanitizers. These help
642 catch bad memory accesses (e.g. buffer overflows), but will make
643 the executable larger and slow down runtime a bit.
645 This adds -fsanitize=foo options to gcc command line.
647 If you aren't developing/testing busybox, say N here.
650 bool "Build unit tests"
653 Say Y here if you want to build unit tests (both the framework and
654 test cases) as an applet. This results in bigger code, so you
655 probably don't want this option in production builds.
658 bool "Abort compilation on any warning"
661 This adds -Werror to gcc command line.
663 Most people should answer N.
665 config WARN_SIMPLE_MSG
666 bool "Warn about single parameter bb_xx_msg calls"
669 This will cause warnings to be shown for any instances of
670 bb_error_msg(), bb_error_msg_and_die(), bb_perror_msg(),
671 bb_perror_msg_and_die(), bb_herror_msg() or bb_herror_msg_and_die()
672 being called with a single parameter. In these cases the equivalent
673 bb_simple_xx_msg function should be used instead.
674 Note that use of STRERROR_FMT may give false positives.
676 If you aren't developing busybox, say N here.
679 prompt "Additional debugging library"
682 Using an additional debugging library will make busybox become
683 considerably larger and will cause it to run more slowly. You
684 should always leave this option disabled for production use.
688 This enables compiling with dmalloc ( http://dmalloc.com/ )
689 which is an excellent public domain mem leak and malloc problem
690 detector. To enable dmalloc, before running busybox you will
691 want to properly set your environment, for example:
692 export DMALLOC_OPTIONS=debug=0x34f47d83,inter=100,log=logfile
693 The 'debug=' value is generated using the following command
694 dmalloc -p log-stats -p log-non-free -p log-bad-space \
695 -p log-elapsed-time -p check-fence -p check-heap \
696 -p check-lists -p check-blank -p check-funcs -p realloc-copy \
699 Electric-fence support:
700 -----------------------
701 This enables compiling with Electric-fence support. Electric
702 fence is another very useful malloc debugging library which uses
703 your computer's virtual memory hardware to detect illegal memory
704 accesses. This support will make busybox be considerably larger
705 and run slower, so you should leave this option disabled unless
706 you are hunting a hard to find memory problem.
716 bool "Electric-fence"
720 source libbb/Config.in
726 source archival/Config.in
727 source coreutils/Config.in
728 source console-tools/Config.in
729 source debianutils/Config.in
730 source klibc-utils/Config.in
731 source editors/Config.in
732 source findutils/Config.in
733 source init/Config.in
734 source loginutils/Config.in
735 source e2fsprogs/Config.in
736 source modutils/Config.in
737 source util-linux/Config.in
738 source miscutils/Config.in
739 source networking/Config.in
740 source printutils/Config.in
741 source mailutils/Config.in
742 source procps/Config.in
743 source runit/Config.in
744 source selinux/Config.in
745 source shell/Config.in
746 source sysklogd/Config.in