Please see the LICENSE file for copyright information.
+
+BusyBox combines tiny versions of many common UNIX utilities into a single
+small executable. It provides minimalist replacements for most of the utilities
+you usually find in fileutils, shellutils, findutils, textutils, grep, gzip,
+tar, etc. BusyBox provides a fairly complete POSIX environment for any small or
+embedded system. The utilities in BusyBox generally have fewer options than
+their full featured GNU cousins; however, the options that are included provide
+the expected functionality and behave very much like their GNU counterparts.
-Busybox is a multicall binary used to provide a minimal subset of
-POSIX style commands and specialized functions.
+BusyBox has been written with size-optimization and limited resources in mind.
+It is also extremely modular so you can easily include or exclude commands (or
+features) at compile time. This makes it easy to customize your embedded
+systems. To create a working system, just add /dev, /etc, and a kernel.
-It is geared toward 'mini-systems' like boot floppies. Specifically
-it is used in the Debian Rescue/Install system (which caused the
-original busybox to be made), the Linux Router Project, and others.
+BusyBox was originally written to support the Debian Rescue/Install disks, but
+it also makes an excellent environment for any small or embedded system.
-As of version 0.20 there is a version number. : )
-Also as of version 0.20, BB is modularized to allow an easy build of
-only the BB parts you need, to reduce binary size.
+As of version 0.20 there is now a version number. : ) Also as of version 0.20,
+BusyBox is now modularized to easily allow you to build only the components you
+need, thereby reducing binary size. To turn off unwanted BusyBox components,
+simply edit the file "Config.h" and comment out the components you do not need
+using C++ style (//) comments.
-Edit the file busybox.def.h and comment out the parts you do not need
-using C++ comments (//)
+After the build is complete, a busybox.links file is generated. This is
+used by 'make install' to create symlinks to the busybox binary for all
+compiled in functions. By default, 'make install' will place the symlink
+forest into `pwd`/_install unless you have defined the PREFIX environment
+variable (i.e., 'make PREFIX=/tmp/foo install')
-After the build is complete a busybox.links file is generated to allow
-you to easily make the sym/hard links to the busybox binary.
+----------------
+
+Supported architectures:
-Note the modular system is Makefile based, and purposly very
-simplistic. It does no dependency checking. That is left for you
-to figure out by trial and error.
+ Busybox in general will build on any architecture supported by gcc. It has
+ a few specialized features added for __sparc__ and __alpha__. insmod
+ functionality is currently limited to x86, ARM, SH3/4, powerpc, m68k,
+ MIPS, and v850e.
+
+Supported libcs:
+
+ glibc-2.0.x, glibc-2.1.x, glibc-2.2.x, Linux-libc5, uClibc. People
+ are looking at newlib and diet-libc, but consider them unsupported,
+ untested, or worse.
+
+Supported kernels:
+
+ Full functionality requires Linux 2.0.x, 2.2.x, or 2.4.x. A large fraction
+ of the code should run on just about anything.
+
+----------------
+
+Shells:
+
+lash is the very smallest shell (adds just 10k) and it is quite usable as
+a command prompt, but it is not suitable for any but the most trivial
+scripting (such as an initrd that calls insmod a few times) since it does
+not understand Bourne shell grammer. It does handle pipes, redirects, and
+job control though. Adding in command editing makes it a very nice
+lightweight command prompt.
+
+hush is also quite small (just 18k) and it has very complete Bourne shell
+grammer. It handles if/then/else/fi just fine, but doesn't handle loops
+like for/do/done or case/esac and such. It also currently has a problem
+with job control. Using hush is not yet recommended.
+
+msh: The minix shell (adds just 30k) is quite complete and handles things
+like for/do/done, case/esac and all the things you expect a Bourne shell to
+do. It is not always pedantically correct about Bourne shell grammer (try
+running the shell testscript "tests/sh.testcases" on it and compare vs bash)
+but for most things it works quite well. It also uses only vfork, so it can
+be used on uClinux systems. This was only recently added, so there is still
+room to shrink it further...
+
+ash: This adds about 60k in the default configuration and is the most
+complete and most pedantically correct shell included with busybox. This
+shell was also recently added, and several people (mainly Vladimir and Erik)
+have been working on it. There are a number of configurable things at the
+top of ash.c as well, so check those out if you want to tweak things.
+
+----------------
+
+Getting help:
+
+When you find you need help, you can check out the BusyBox mailing list
+archives at http://busybox.net/lists/busybox/ or even join
+the mailing list if you are interested.
+
+----------------
+
+Bugs:
+
+If you find bugs, please submit a bug report. Full instructions on how to
+report a bug are found at http://bugs.busybox.net/Reporting.html.
+
+For the impatient: To submit a bug, simply send an email describing the problem
+to submit@bugs.busybox.net. Bug reports should look something like this:
+
+ To: submit@bugs.busybox.net
+ From: diligent@testing.linux.org
+ Subject: /bin/true doesn't work
+
+ Package: busybox
+ Version: 0.51
+
+ When I invoke '/bin/true' it doesn't work. I expected it to return
+ a "0" but it returned a "1" instead. Here is the transcript:
+ $ /bin/true ; echo $?
+ 1
+ With GNU /bin/true, I get the following output:
+ $ /bin/true ; echo $?
+ 0
+ I am using Debian 2.2r2, kernel version 2.2.18, and the latest
+ uClibc from CVS. Thanks for the wonderful program!
+ -Diligent
+
+Note the careful description and use of examples showing not only what BusyBox
+does, but also a counter example showing what an equivalent GNU app does. Bug
+reports lacking such detail may take a _long_ time to be fixed... Thanks for
+understanding.
+
+----------------
+
+FTP:
+
+Source for the latest released version, as well as daily snapshots, can always
+be downloaded from
+ http://busybox.net/downloads/
+
+----------------
+
+CVS:
+
+BusyBox now has its own publicly browsable CVS tree at:
+ http://busybox.net/cgi-bin/cvsweb/busybox/
+
+Anonymous CVS access is available. For instructions, check out:
+ http://busybox.net/cvs_anon.html
+
+For those that are actively contributing there is even CVS write access:
+ http://busybox.net/cvs_write.html
+
+----------------
+
+Please feed suggestions, bug reports, insults, and bribes back to:
+ Erik Andersen
+ <andersen@codepoet.org>
+ <andersee@debian.org>
-Please feed patches back to:
- Dave Cinege <dcinege@psychosis.com>
-and:
- Enrique Zanardi <ezanardi@ull.es>
projects / oweals / busybox.git / blobdiff