1<html><head><title>What is toybox?</title>
   2<!--#include file="header.html" -->
   4<h2><a name="what" />What is toybox?</h2>
   6<p>Toybox combines many common Linux command line utilities together into
   7a single <a href=license.html>BSD-licensed</a> executable. It's simple, small, fast, and reasonably
   8standards-compliant (<a href=>POSIX-2008</a> and <a href=>LSB 4.1</a>).</p>
  10<p>Toybox's main goal is to make Android
  11<a href=>self-hosting</a>
  12by improving Android's command line utilities so it can
  13build an installable Android Open Source Project image
  14entirely from source under a stock Android system. After a talk at the 2013
  15Embedded Linux Conference explaining this plan
  16(<a href=>outline</a>,
  17<a href=>video</a>), Google
  18<a href=>merged toybox into AOSP</a> and
  19began shipping toybox in Android Marshmallow in 2015.</p>
  21<p>Toybox aims to provide one quarter of a theoretical "minimal native
  22development environment", which is the simplest Linux system capable of
  23rebuilding itself from source code and then building
  24<a href=>Linux From Scratch</a>
  25and the <a href=>Android Open Source Project</a>
  26under the result. In theory, this should only require four packages:
  271) a set of posix-ish command line utilities,
  282) a compiler<a name="1_back"></a><sup><font size=-3><a href=#1>[1]</a></font></sup>,
  293) a C library, and 4) a kernel. This provides a reproducible and auditable
  30base system, which with the addition of a few convienciences (vi, top,
  31shell command line history...) can provide a usable interactive experience
  32rather than just a headless build server.</p>
  34<b><h2><a name="why" />Why is toybox?</h2></b>
  36<p>The <a href=>2013 toybox talk</a>
  37at ELC was devoted to this question, and has the following sections:</p>
  40<li>0m29s <a href=>The smartphone is replacing the PC</a></li>
  41  <ul>
  42  <li>4m22s <a href=>Software needed to become self-hosting</a></li>
  43  <li>6m20s <a href=>Do we care if android or iphone wins?</a></li>
  44  </ul>
  45<li>9m45s <a href=>Android not vanilla: oppose or accept?</a></li>
  46  <ul>
  47  <li>11m30s <a href=>Open source can't do User Interfaces</a></li>
  48  </ul>
  49<li>15m09s <a href=>Android is not copyleft: oppose or accept?</a></li>
  50<li>18m23s <a href=>Security issues</a></li>
  51<li>21m15s <a href=>Solutions to the software problems</a></li>
  52  <ul>
  53  <li>22m55s <a href=>What toybox needs to be/do</a></li>
  54  <li>28m17s <a href=>What is toybox?</a></li>
  55    <ul>
  56    <li>28m58s <a href=>Why toybox started...</a></li>
  57    <li>37m50s <a href=>What does toybox actually implement?</a></li>
  58    </ul>
  59  </ul>
  62<p>A more recent talk from 2019 compares
  63<a href=>BusyBox vs toybox</a>
  64and explains the design decisions behind both.
  65(A 2015 toybox talk was part of the channel
  66<a href=>accidentally deleted</a> off youtube by the Linux Foundation,
  67but the <a href=>outline</a> is
  68still available.)</p>
  70<b><h2><a name="context" />What context was toybox created in?</h2></b>
  72<p>The toybox maintainer's previous minimal self-hosting system project,
  73<a href=>Aboriginal Linux</a>,
  74got a native development environment down to only seven packages in
  75its 1.0 release (busybox, uClibc, gcc, binutils, make, bash, and linux)
  76and then built Linux From Scratch under the result. That project
  77<a href=>was the reason</a>
  78toybox's maintainer became busybox maintainer, having done so
  79much work to extend busybox to replace all the gnu tools in a Linux From
  80Scratch build that the previous maintainer handed over the project (to
  81spend more time on buildroot).</p>
  83<p>Despite the maintainer's history with busybox, toybox is a fresh
  84from-scratch implementation under an
  85<a href=>android-compatible</a>
  86<a href=license.html>license</a>. Busybox predates Android, but has never
  87shipped with Android due to the license. As long as we're starting over anyway,
  88we can do a better job.</p>
  90<p>Toybox's current minimal native development environment builder is a new
  91<a href=>tiny
  92implementation</a> integrated into the toybox source.
  93The "make root" target will create a simple toybox chroot
  94(by default in the root/host directory), and adding a LINUX= argument to
  95the make command line pointing to Linux kernel source code creates a tiny
  96bootable system with a wrapper script to run it under the emulator
  97<a href=>qemu</a>.</p>
  99<p>The list of commands remaining before we can build Linux From Scratch under
 100the result (with an appropriate
 101<a href=>compiler</a>)
 102is tracked <a href=roadmap.html#dev_env>in
 103the roadmap</a>, and doing so is one of the main goals for toybox's 1.0
 106<p>Building LFS requres fewer commands than building AOSP, which has a lot more
 107<a href=>build
 108prerequisites</a>. In theory some of those can be built from source
 109as external packages (we're clearly not including our own java implementation),
 110but some early prerequisites may need to be added to bootstrap AOSP far enough
 111to build them (such as a read-only version of "git":
 112how does repo download the AOSP source otherwise?)
 113<a name="2_back"></a><sup><font size=-3><a href=#2>[2]</a></font></sup></p>
 115<b><h2><a name="status" />What commands are planned/implemented in toybox?</h2></b>
 117<p>The current list of commands implemented by toybox is on the
 118<a href=status.html>status page</a>, which is updated each release.
 119There is also a <a href=roadmap.html>roadmap</a> listing all planned commands
 120for the 1.0 release and the reasons for including them.</p>
 122<p>In general, configuring toybox with "make defconfig" enables all the commands
 123compete enough to be useful. Configuring "allyesconfig" enables partially
 124implemented commands as well, along with debugging features.</p>
 126<b><h3>Relevant Standards</h3></b>
 128<p>Most commands are implemented according to POSIX-2008 (I.E.
 129<a href=>The
 130Single Unix Specification version 4</a>) where applicable. This does not mean
 131that toybox is implementing every SUSv4 utility: some such as SCCS and ed are
 132obsolete, while others such as c99 are outside the scope of the project.
 133Toybox also isn't implementing full internationalization support: it should be
 1348-bit clean and handle UTF-8, but otherwise we leave this to X11 and higher
 135layers. And some things (like $CDPATH support in "cd") await a good
 136explanation of why to bother with them. (POSIX provides an important
 137frame of reference, but is not an infallable set of commandments to be blindly
 138obeyed. We do try to document our deviations from it in the comment section
 139at the start of each command under toys/posix.)</p>
 141<p>The other major sources of commands are the Linux man pages, the
 142Linux Standard Base, and testing the behavior of existing command
 143implementations (although not generally looking at their
 144source code), including the commands in Android's toolbox. SUSv4 does not
 145include many basic commands such as "mount", "init", and "mke2fs", which are
 146kind of nice to have.</p>
 148<p>For more on this see the <a href=roadmap.html>roadmap</a> and
 149<a href=design.html>design goals</a>.</p>
 151<b><h2><a name="downloads" />Download</h2></b>
 153<p>This project is maintained as a <a href=>git
 154archive</a>, and also offers <a href=>source
 155tarballs</a> and <a href=>static binaries</a>
 156of the release versions.</p>
 158<p>The maintainer's <a href=>development log</a> and the project's
 159<a href=>mailing
 160list</a> are also good ways to track what's going on with the project.</p>
 162<b><h2><a name="toycans" />What's the toybox logo image?</h2></b>
 164<p>It's <a href=toycans-big.jpg>carefully stacked soda cans</a>. Specifically,
 165it's a bunch of the original "Coke Zero" and "Pepsi One" cans, circa 2006,
 166stacked to spell out the binary values of the ascii string "Toybox", with
 167null terminator at the bottom. (The big picture's on it's side because
 168the camera was held sideways to get a better shot.)</p>
 170<p>No, it's not photoshopped, I actually had these cans until a coworker
 171who Totally Did Not Get It <sup><font size=-3><a href=>tm</a></font></sup> threw them out one day after I'd gone home,
 172thinking they were recycling. (I still have two of each kind, but
 173Pepsi One seems discontinued and Coke Zero switched its can color
 174from black to grey, presumably in celebration. It was fun while it lasted...)</p>
 178<p><a name="1" /><a href="#1_back">[1]</a> Ok, most toolchains (gcc, llvm, pcc, libfirm...)
 179are multiple packages, but the maintainer of toybox used to maintain a
 180<a href=>fork of tinycc</a> (an integrated
 181compiler/assembler/linker which once upon a
 182time did <a href=>build a bootable linux
 183kernel</a> before its original developer abandoned the project),
 184and has <a href=>vague plans</a> of <a href=>trying
 185again someday</a>. The compiler toolchain is _conceptually_ one package,
 186implementable as a single multicall binary acting like make, cc, as, ld, cpp,
 187strip, readelf, nm, objdump, and so on as necessary. It's just the existing
 188packages that do this <strike>kinda suck</strike> don't. (In theory "make"
 189belongs in qcc, in practice llvm hasn't got its own make so toybox probably
 190needs to add it after 1.0 to eliminate another gpl build prerequite from
 193<p><a name="2" /><a href="#2_back">[2]</a>
 194The dividing line is
 195"Is there an acceptably licensed version Android can ship, or do we have
 196to write one?" Since android is not "GNU/Linux" in any way, we need to
 197clean out all traces of gnu software from its build to get a clean
 198self-hosting system.</p>
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