README - third_party/toybox - Git at Google

 Toybox: all-in-one Linux command line.

 --- Getting started

 You can download static binaries for various targets from:

   http://landley.net/toybox/bin

 The special name "." indicates the current directory (just like ".." means
 the parent directory), and you can run a program that isn't in the $PATH by
 specifying a path to it, so this should work:

   wget http://landley.net/toybox/bin/toybox-x86_64
   chmod +x toybox-x86_64
   ./toybox-x86_64 echo hello world

 --- Building toybox

 Type "make help" for build instructions.

 Toybox uses the "make menuconfig; make; make install" idiom same as
 the Linux kernel. Usually you want something like:

   make defconfig
   make
   make install

 Or maybe:

   LDFLAGS="--static" CROSS_COMPILE=armv5l- make defconfig toybox
   PREFIX=/path/to/root/filesystem/bin make install_flat

 The file "configure" defines default values for many environment
 variables that control the toybox build; if you set a value for any of
 these, your value is used instead of the default in that file.

 The CROSS_COMPILE argument above is optional, the default builds a version of
 toybox to run on the current machine. Cross compiling requires an appropriately
 prefixed cross compiler toolchain, several example toolchains are available at:

   http://landley.net/aboriginal/bin

 For the "CROSS_COMPILE=armv5l-" example above, download
 cross-compiler-armv5l.tar.bz2, extract it, and add its "bin" subdirectory to
 your $PATH. (And yes, the trailing - is significant, because the prefix
 includes a dash.)

 For more about cross compiling, see:

   http://landley.net/writing/docs/cross-compiling.html
   http://landley.net/aboriginal/architectures.html

 For a more thorough description of the toybox build process, see
 http://landley.net/toybox/code.html#building

 --- Using toybox

 The toybox build produces a multicall binary, a "swiss-army-knife" program
 that acts differently depending on the name it was called by (cp, mv, cat...).
 Installing toybox adds symlinks for each command name to the $PATH.

 The special "toybox" command treats its first argument as the command to run.
 With no arguments, it lists available commands. This allows you to use toybox
 without installing it. This is the only command that can have an arbitrary
 suffix (hence "toybox-armv5l").

 The "help" command provides information about each command (ala "help cat").

 --- Configuring toybox

 It works like the Linux kernel: allnoconfig, defconfig, and menuconfig edit
 a ".config" file that selects which features to include in the resulting
 binary. You can save and re-use your .config file, although may want to
 run "make oldconfig" to re-run the dependency resolver when migrating to
 new versions.

 The maximum sane configuration is "make defconfig": allyesconfig isn't
 recommended for toybox because it enables unfinished commands and debug code.

 --- Creating a Toybox-based Linux system

 Toybox is not a complete operating system, it's a program that runs under
 an operating system. Booting a simple system to a shell prompt requires
 three packages: an operating system kernel (Linux*) to drive the hardware,
 one or more programs for the system to run (toybox), and a C library ("libc")
 to tie them together (toybox has been tested with musl, uClibc, glibc,
 and bionic).

 The C library is part of a "toolchain", which is an integrated suite
 of compiler, assembler, and linker, plus the standard headers and libraries
 necessary to build C programs. (And miscellaneous binaries like nm and objdump.)

 Static linking (with the --static option) copies the shared library contents
 into the program, resulting in larger but more portable programs, which
 can run even if they're the only file in the filesystem. Otherwise,
 the "dynamically" linked programs require the library files to be present on
 the target system ("man ldd" and "man ld.so" for details).

 An example toybox-based system is Aboriginal Linux:

   http://landley.net/aboriginal/about.html

 That's designed to run under qemu, emulating several different hardware
 architectures (x86, x86-64, arm, mips, sparc, powerpc, sh4). Each toybox
 release is regression tested by building Linux From Scratch under this
 toybox-based system on each supported architecture, using QEMU to emulate
 big and little endian systems with different word size and alignment
 requirements. (The eventual goal is to replace Linux From Scratch with
 the Android Open Source Project.)

 * Or something providing the same API such as FreeBSD's Linux emulation layer.

 --- Presentations

 1) "Why Toybox?" talk at the Embedded Linux Conference in 2013

     video: http://youtu.be/SGmtP5Lg_t0
     outline: http://landley.net/talks/celf-2013.txt
     linked from http://landley.net/toybox/ in nav bar on left as "Why is it?"
     - march 21, 2013 entry has section links.

 2) "Why Public Domain?" The rise and fall of copyleft, Ohio LinuxFest 2013

     audio: https://archive.org/download/OhioLinuxfest2013/24-Rob_Landley-The_Rise_and_Fall_of_Copyleft.mp3
     outline: http://landley.net/talks/ohio-2013.txt

 3) Why did I do Aboriginal Linux (which led me here)

     260 slide presentation:
     https://speakerdeck.com/landley/developing-for-non-x86-targets-using-qemu

     How and why to make android self-hosting:
       http://landley.net/aboriginal/about.html#selfhost

 4) What's new with toybox (ELC 2015 status update):

     video: http://elinux.org/ELC_2015_Presentations
     outline: http://landley.net/talks/celf-2015.txt

 --- Contributing

 The three important URLs for communicating with the toybox project are:

   web page: http://landley.net/toybox

   mailing list: http://lists.landley.net/listinfo.cgi/toybox-landley.net

   git repo: http://github.com/landley/toybox

 The maintainer prefers patches be sent to the mailing list. If you use git,
 the easy thing to do is:

   git format-patch -1 $HASH

 Then send a file attachment. The list holds messages from non-subscribers
 for moderation, but I usually get to them in a day or two.

 Although I do accept pull requests on github, I download the patches and
 apply them with "git am" (which avoids gratuitous merge commits). Closing
 the pull request is then the submitter's responsibility.

 If I haven't responded to your patch after one week, feel free to remind
 me of it.

 Android's policy for toybox patches is that non-build patches should go
 upstream first (into vanilla toybox, with discussion on the toybox mailing
 list) and then be pulled into android's toybox repo from there. (They
 generally resync on fridays). The exception is patches to their build scripts
 (Android.mk and the checked-in generated/* files) which go directly to AOSP.
	Toybox: all-in-one Linux command line.

	--- Getting started

	You can download static binaries for various targets from:

	http://landley.net/toybox/bin

	The special name "." indicates the current directory (just like ".." means
	the parent directory), and you can run a program that isn't in the $PATH by
	specifying a path to it, so this should work:

	wget http://landley.net/toybox/bin/toybox-x86_64
	chmod +x toybox-x86_64
	./toybox-x86_64 echo hello world

	--- Building toybox

	Type "make help" for build instructions.

	Toybox uses the "make menuconfig; make; make install" idiom same as
	the Linux kernel. Usually you want something like:

	make defconfig
	make
	make install

	Or maybe:

	LDFLAGS="--static" CROSS_COMPILE=armv5l- make defconfig toybox
	PREFIX=/path/to/root/filesystem/bin make install_flat

	The file "configure" defines default values for many environment
	variables that control the toybox build; if you set a value for any of
	these, your value is used instead of the default in that file.

	The CROSS_COMPILE argument above is optional, the default builds a version of
	toybox to run on the current machine. Cross compiling requires an appropriately
	prefixed cross compiler toolchain, several example toolchains are available at:

	http://landley.net/aboriginal/bin

	For the "CROSS_COMPILE=armv5l-" example above, download
	cross-compiler-armv5l.tar.bz2, extract it, and add its "bin" subdirectory to
	your $PATH. (And yes, the trailing - is significant, because the prefix
	includes a dash.)

	For more about cross compiling, see:

	http://landley.net/writing/docs/cross-compiling.html
	http://landley.net/aboriginal/architectures.html

	For a more thorough description of the toybox build process, see
	http://landley.net/toybox/code.html#building

	--- Using toybox

	The toybox build produces a multicall binary, a "swiss-army-knife" program
	that acts differently depending on the name it was called by (cp, mv, cat...).
	Installing toybox adds symlinks for each command name to the $PATH.

	The special "toybox" command treats its first argument as the command to run.
	With no arguments, it lists available commands. This allows you to use toybox
	without installing it. This is the only command that can have an arbitrary
	suffix (hence "toybox-armv5l").

	The "help" command provides information about each command (ala "help cat").

	--- Configuring toybox

	It works like the Linux kernel: allnoconfig, defconfig, and menuconfig edit
	a ".config" file that selects which features to include in the resulting
	binary. You can save and re-use your .config file, although may want to
	run "make oldconfig" to re-run the dependency resolver when migrating to
	new versions.

	The maximum sane configuration is "make defconfig": allyesconfig isn't
	recommended for toybox because it enables unfinished commands and debug code.

	--- Creating a Toybox-based Linux system

	Toybox is not a complete operating system, it's a program that runs under
	an operating system. Booting a simple system to a shell prompt requires
	three packages: an operating system kernel (Linux*) to drive the hardware,
	one or more programs for the system to run (toybox), and a C library ("libc")
	to tie them together (toybox has been tested with musl, uClibc, glibc,
	and bionic).

	The C library is part of a "toolchain", which is an integrated suite
	of compiler, assembler, and linker, plus the standard headers and libraries
	necessary to build C programs. (And miscellaneous binaries like nm and objdump.)

	Static linking (with the --static option) copies the shared library contents
	into the program, resulting in larger but more portable programs, which
	can run even if they're the only file in the filesystem. Otherwise,
	the "dynamically" linked programs require the library files to be present on
	the target system ("man ldd" and "man ld.so" for details).

	An example toybox-based system is Aboriginal Linux:

	http://landley.net/aboriginal/about.html

	That's designed to run under qemu, emulating several different hardware
	architectures (x86, x86-64, arm, mips, sparc, powerpc, sh4). Each toybox
	release is regression tested by building Linux From Scratch under this
	toybox-based system on each supported architecture, using QEMU to emulate
	big and little endian systems with different word size and alignment
	requirements. (The eventual goal is to replace Linux From Scratch with
	the Android Open Source Project.)

	* Or something providing the same API such as FreeBSD's Linux emulation layer.

	--- Presentations

	1) "Why Toybox?" talk at the Embedded Linux Conference in 2013

	video: http://youtu.be/SGmtP5Lg_t0
	outline: http://landley.net/talks/celf-2013.txt
	linked from http://landley.net/toybox/ in nav bar on left as "Why is it?"
	- march 21, 2013 entry has section links.

	2) "Why Public Domain?" The rise and fall of copyleft, Ohio LinuxFest 2013

	audio: https://archive.org/download/OhioLinuxfest2013/24-Rob_Landley-The_Rise_and_Fall_of_Copyleft.mp3
	outline: http://landley.net/talks/ohio-2013.txt

	3) Why did I do Aboriginal Linux (which led me here)

	260 slide presentation:
	https://speakerdeck.com/landley/developing-for-non-x86-targets-using-qemu

	How and why to make android self-hosting:
	http://landley.net/aboriginal/about.html#selfhost

	4) What's new with toybox (ELC 2015 status update):

	video: http://elinux.org/ELC_2015_Presentations
	outline: http://landley.net/talks/celf-2015.txt

	--- Contributing

	The three important URLs for communicating with the toybox project are:

	web page: http://landley.net/toybox

	mailing list: http://lists.landley.net/listinfo.cgi/toybox-landley.net

	git repo: http://github.com/landley/toybox

	The maintainer prefers patches be sent to the mailing list. If you use git,
	the easy thing to do is:

	git format-patch -1 $HASH

	Then send a file attachment. The list holds messages from non-subscribers
	for moderation, but I usually get to them in a day or two.

	Although I do accept pull requests on github, I download the patches and
	apply them with "git am" (which avoids gratuitous merge commits). Closing
	the pull request is then the submitter's responsibility.

	If I haven't responded to your patch after one week, feel free to remind
	me of it.

	Android's policy for toybox patches is that non-build patches should go
	upstream first (into vanilla toybox, with discussion on the toybox mailing
	list) and then be pulled into android's toybox repo from there. (They
	generally resync on fridays). The exception is patches to their build scripts
	(Android.mk and the checked-in generated/* files) which go directly to AOSP.