config DESKTOP
bool "Enable options for full-blown desktop systems"
- default n
+ default y
help
Enable options and features which are not essential.
Select this only if you plan to use busybox on full-blown
compiler other than gcc.
If you do use gcc, this option may needlessly increase code size.
+config PLATFORM_LINUX
+ bool "Enable Linux-specific applets and features"
+ default y
+ help
+ For the most part, busybox requires only POSIX compatibility
+ from the target system, but some applets and features use
+ Linux-specific interfaces.
+
+ Answering 'N' here will disable such applets and hide the
+ corresponding configuration options.
+
choice
prompt "Buffer allocation policy"
default FEATURE_BUFFERS_USE_MALLOC
endchoice
config SHOW_USAGE
- bool "Show terse applet usage messages"
+ bool "Show applet usage messages"
default y
help
- All BusyBox applets will show help messages when invoked with
- wrong arguments. You can turn off printing these terse usage
- messages if you say no here.
- This will save you up to 7k.
+ Enabling this option, BusyBox applets will show terse help messages
+ when invoked with wrong arguments.
+ If you do not want to show any (helpful) usage message when
+ issuing wrong command syntax, you can say 'N' here,
+ saving approximately 7k.
config FEATURE_VERBOSE_USAGE
bool "Show verbose applet usage messages"
default y
depends on SHOW_USAGE
help
- All BusyBox applets will show more verbose help messages when
+ All BusyBox applets will show verbose help messages when
busybox is invoked with --help. This will add a lot of text to the
busybox binary. In the default configuration, this will add about
13k, but it can add much more depending on your configuration.
default y
depends on SHOW_USAGE
help
- Store usage messages in compressed form, uncompress them on-the-fly
- when <applet> --help is called.
+ Store usage messages in .bz compressed form, uncompress them
+ on-the-fly when <applet> --help is called.
If you have a really tiny busybox with few applets enabled (and
bunzip2 isn't one of them), the overhead of the decompressor might
and have very little memory, this might not be a win. Otherwise,
you probably want this.
+config BUSYBOX
+ bool "Include busybox applet"
+ default y
+ help
+ The busybox applet provides general help regarding busybox and
+ allows the included applets to be listed. It's also required
+ if applet links are to be installed at runtime.
+
+ If you can live without these features disabling this will save
+ some space.
+
config FEATURE_INSTALLER
bool "Support --install [-s] to install applet links at runtime"
default y
+ depends on BUSYBOX
help
Enable 'busybox --install [-s]' support. This will allow you to use
busybox at runtime to create hard links or symlinks for all the
applets that are compiled into busybox.
+config INSTALL_NO_USR
+ bool "Don't use /usr"
+ default n
+ help
+ Disable use of /usr. busybox --install and "make install"
+ will install applets only to /bin and /sbin,
+ never to /usr/bin or /usr/sbin.
+
config LOCALE_SUPPORT
bool "Enable locale support (system needs locale for this to work)"
default n
help
With this option on, Unicode support is implemented using libc
routines. Otherwise, internal implementation is used.
+ Internal implementation is smaller.
config FEATURE_CHECK_UNICODE_IN_ENV
- bool "Check $LANG environment variable"
+ bool "Check $LC_ALL, $LC_CTYPE and $LANG environment variables"
default n
depends on UNICODE_SUPPORT && !UNICODE_USING_LOCALE
help
With this option on, Unicode support is activated
- only if LANG variable has the value of the form "xxxx.utf8"
+ only if locale-related variables have the value of the form
+ "xxxx.utf8"
Otherwise, Unicode support will be always enabled and active.
default n
depends on UNICODE_SUPPORT
help
- With this option on, invalid UTF-8 bytes are not substituted
- with the selected substitution character.
+ With this option on, on line-editing input (such as used by shells)
+ invalid UTF-8 bytes are not substituted with the selected
+ substitution character.
For example, this means that entering 'l', 's', ' ', 0xff, [Enter]
at shell prompt will list file named 0xff (single char name
with char value 255), not file named '?'.
+config PAM
+ bool "Support for PAM (Pluggable Authentication Modules)"
+ default n
+ help
+ Use PAM in some busybox applets (currently login and httpd) instead
+ of direct access to password database.
+
+config FEATURE_USE_SENDFILE
+ bool "Use sendfile system call"
+ default y
+ select PLATFORM_LINUX
+ help
+ When enabled, busybox will use the kernel sendfile() function
+ instead of read/write loops to copy data between file descriptors
+ (for example, cp command does this a lot).
+ If sendfile() doesn't work, copying code falls back to read/write
+ loop. sendfile() was originally implemented for faster I/O
+ from files to sockets, but since Linux 2.6.33 it was extended
+ to work for many more file types.
+
config LONG_OPTS
bool "Support for --long-options"
default y
config FEATURE_WTMP
bool "Support wtmp file"
default y
- select FEATURE_UTMP
+ depends on FEATURE_UTMP
help
The file /var/run/wtmp is used to track when users have logged into
and logged out of the system.
default y
help
This option makes some applets (e.g. crond, syslogd, inetd) write
- a pidfile in /var/run. Some applications rely on them.
+ a pidfile at the configured PID_FILE_PATH. It has no effect
+ on applets which require pidfiles to run.
+
+config PID_FILE_PATH
+ string "Path to directory for pidfile"
+ default "/var/run"
+ depends on FEATURE_PIDFILE
+ help
+ This is the default path where pidfiles are created. Applets which
+ allow you to set the pidfile path on the command line will override
+ this value. The option has no effect on applets that require you to
+ specify a pidfile path.
config FEATURE_SUID
bool "Support for SUID/SGID handling"
default y
help
With this option you can install the busybox binary belonging
- to root with the suid bit set, and it will automatically drop
- priviledges for applets that don't need root access.
+ to root with the suid bit set, enabling some applets to perform
+ root-level operations even when run by ordinary users
+ (for example, mounting of user mounts in fstab needs this).
+
+ Busybox will automatically drop privileges for applets
+ that don't need root access.
If you are really paranoid and don't want to do this, build two
busybox binaries with different applets in them (and the appropriate
symlinks pointing to each binary), and only set the suid bit on the
- one that needs it. The applets currently marked to need the suid bit
- are:
+ one that needs it.
+
+ The applets which require root rights (need suid bit or
+ to be run by root) and will refuse to execute otherwise:
+ crontab, login, passwd, su, vlock, wall.
- crontab, dnsd, findfs, ipcrm, ipcs, login, passwd, ping, su,
- traceroute, vlock.
+ The applets which will use root rights if they have them
+ (via suid bit, or because run by root), but would try to work
+ without root right nevertheless:
+ findfs, ping[6], traceroute[6], mount.
+
+ Note that if you DONT select this option, but DO make busybox
+ suid root, ALL applets will run under root, which is a huge
+ security hole (think "cp /some/file /etc/passwd").
config FEATURE_SUID_CONFIG
bool "Runtime SUID/SGID configuration via /etc/busybox.conf"
- default y if FEATURE_SUID
+ default y
depends on FEATURE_SUID
help
Allow the SUID / SGID state of an applet to be determined at runtime
by checking /etc/busybox.conf. (This is sort of a poor man's sudo.)
The format of this file is as follows:
- <applet> = [Ssx-][Ssx-][x-] (<username>|<uid>).(<groupname>|<gid>)
+ APPLET = [Ssx-][Ssx-][x-] [USER.GROUP]
+
+ s: USER or GROUP is allowed to execute APPLET.
+ APPLET will run under USER or GROUP
+ (reagardless of who's running it).
+ S: USER or GROUP is NOT allowed to execute APPLET.
+ APPLET will run under USER or GROUP.
+ This option is not very sensical.
+ x: USER/GROUP/others are allowed to execute APPLET.
+ No UID/GID change will be done when it is run.
+ -: USER/GROUP/others are not allowed to execute APPLET.
An example might help:
su = ssx # exactly the same
mount = sx- root.disk # applet mount can be run by root and members
- # of group disk and runs with euid=0
+ # of group disk (but not anyone else)
+ # and runs with euid=0 (egid is not changed)
cp = --- # disable applet cp for everyone
config SELINUX
bool "Support NSA Security Enhanced Linux"
default n
+ select PLATFORM_LINUX
help
Enable support for SELinux in applets ls, ps, and id. Also provide
the option of compiling in SELinux applets.
If you do not have a complete SELinux userland installed, this stuff
- will not compile. Go visit
- http://www.nsa.gov/selinux/index.html
- to download the necessary stuff to allow busybox to compile with
- this option enabled. Specifially, libselinux 1.28 or better is
+ will not compile. Specifially, libselinux 1.28 or better is
directly required by busybox. If the installation is located in a
non-standard directory, provide it by invoking make as follows:
CFLAGS=-I<libselinux-include-path> \
default n
depends on !STATIC
help
- (TODO: what is it and why/when is it useful?)
+ Hardened code option. PIE binaries are loaded at a different
+ address at each invocation. This has some overhead,
+ particularly on x86-32 which is short on registers.
+
Most people will leave this set to 'N'.
config NOMMU
config LFS
bool "Build with Large File Support (for accessing files > 2 GB)"
default y
- select FDISK_SUPPORT_LARGE_DISKS
help
If you want to build BusyBox with large file support, then enable
this option. This will have no effect if your kernel or your C
Native builds leave this empty.
+config SYSROOT
+ string "Path to sysroot"
+ default ""
+ help
+ If you want to build BusyBox with a cross compiler, then you
+ might also need to specify where /usr/include and /usr/lib
+ will be found.
+
+ For example, BusyBox can be built against an installed
+ Android NDK, platform version 9, for ARM ABI with
+
+ CONFIG_SYSROOT=/opt/android-ndk/platforms/android-9/arch-arm
+
+ Native builds leave this empty.
+
config EXTRA_CFLAGS
string "Additional CFLAGS"
default ""
help
Additional CFLAGS to pass to the compiler verbatim.
+config EXTRA_LDFLAGS
+ string "Additional LDFLAGS"
+ default ""
+ help
+ Additional LDFLAGS to pass to the linker verbatim.
+
+config EXTRA_LDLIBS
+ string "Additional LDLIBS"
+ default ""
+ help
+ Additional LDLIBS to pass to the linker with -l.
+
endmenu
menu 'Debugging Options'
in a much bigger executable that more closely matches the source
code.
+config DEBUG_SANITIZE
+ bool "Enable runtime sanitizers (ASAN/LSAN/USAN/etc...)"
+ default n
+ help
+ Say Y here if you want to enable runtime sanitizers. These help
+ catch bad memory accesses (e.g. buffer overflows), but will make
+ the executable larger and slow down runtime a bit.
+
+ If you aren't developing/testing busybox, say N here.
+
+config UNIT_TEST
+ bool "Build unit tests"
+ default n
+ help
+ Say Y here if you want to build unit tests (both the framework and
+ test cases) as a Busybox applet. This results in bigger code, so you
+ probably don't want this option in production builds.
+
config WERROR
bool "Abort compilation on any warning"
default n
endchoice
-### config PARSE
-### bool "Uniform config file parser debugging applet: parse"
-
endmenu
-menu 'Installation Options'
-
-config INSTALL_NO_USR
- bool "Don't use /usr"
- default n
- help
- Disable use of /usr. Don't activate this option if you don't know
- that you really want this behaviour.
+menu 'Installation Options ("make install" behavior)'
choice
- prompt "Applets links"
+ prompt "What kind of applet links to install"
default INSTALL_APPLET_SYMLINKS
help
- Choose how you install applets links.
+ Choose what kind of links to applets are created by "make install".
config INSTALL_APPLET_SYMLINKS
bool "as soft-links"
config INSTALL_APPLET_DONT
bool "not installed"
- depends on FEATURE_INSTALLER || FEATURE_SH_STANDALONE || FEATURE_PREFER_APPLETS
help
- Do not install applet links. Useful when using the -install feature
- or a standalone shell for rescue purposes.
+ Do not install applet links. Useful when you plan to use
+ busybox --install for installing links, or plan to use
+ a standalone shell and thus don't need applet links.
endchoice
config INSTALL_SH_APPLET_SCRIPT_WRAPPER
bool "as script wrapper"
help
- Install /bin/sh applet as script wrapper that call the busybox
- binary.
+ Install /bin/sh applet as script wrapper that calls
+ the busybox binary.
endchoice