The easiest way to build 'Minimal Linux Live' is to run the following script:

  ./build_minimal_linux_live.sh

Note that the build process requires proper toolchain already installed and
configured. Check the project website for more information:

  http://minimal.idzona.com

For Ubuntu and other Debian based operating systems you can use the following
command in order to resolve the required build dependencies:

  sudo apt install wget make gawk gcc bc bison flex xorriso libelf-dev libssl-dev

Once you have your ISO image up and running perhaps you'd like to examine the
configuration file '.config' and see what options you have there. For example,
you can change the property 'OVERLAY_BUNDLES' and build your own flavor of MLL.

Currently available overlay bundles:

  all            - this indicates to build all available overlay bundles. This
                   is useful mostly for testing purposes. You are encouraged to
                   use only the overlay bundles that you actually want. 

  GLIBC          - set of all core GNU C libraries packaged together. This
                   overlay bundle is not host specific and can always be built.
                   The libraries are useful if you plan to use more software in
                   MLL. This overlay bundle depends on the GLIBC build process.

  adopt_openjdk  - JDK from AdoptOpenJDK with VM from either HotSpot or OpenJ9. 

  bosh_cli       - BOSH command line tool. It can be used as landscape manager
                   for virtual network and server infrastructures in cloud
                   environments, e.g. AWS, Google Cloud, etc. Common use case
                   for this tool is to manage Cloud Foundry infrastructures.

  c2048          - console version of the game 2048.

  cf_cli         - Cloud Foundry command line tool. It can be used to manage
                   all aspects of already existing Cloud Foundry installation,
                   including the full software development lifecycle in cloud
                   based environment.

  cf_tools       - meta-package which installs all available BOSH and Cloud
                   Foundry tools. Note that in MLL context these tools are
                   mostly useful as remote managers for existing BOSH and
                   Cloud Foundry infrastructures.

  coreutils      - set of commonly used GNU executable utilities.

  dhcp           - DHCP (client) and DNS (resolver) functionality.

  dialog         - shell scripting library for 'ncurses'. This overlay bundle
                   requires 'ncurses'.

  Dropbear       - SSH server/client. This overlay bundle requires some GLIBC
                   libraries. The build process generates new 'root' user with
                   password 'toor'. These are sample commands which demonstrate
                   how to use Dropbear:

                   SSH server (Alt + F1): dropbear -E -F
                   SSH client (Alt + F2): dbclient 10.0.2.15 -l root

  Felix OSGi     - Apache Felix OSGi framework. Use the 'felix-start' command
                   to run the Apache Felix OSGi framework. This overlay bundle
                   requires JRE or JDK.

  fio            - I/O load generator that can simulate a wide variety of
                   workloads on RAM or disks. 'fio' is essential for
                   troubleshooting data I/O bottlenecks.

  Golang         - Go is an open source programming language that makes it easy
                   to build simple, reliable, and efficient software.

  GraalVM        - Universal virtual machine for running applications written
                   in JavaScript, Python, Ruby, R, JVM-based languages like
                   Java, Scala, Clojure, Kotlin, and LLVM-based languages such
                   as C and C++.

  kbd            - keyboard utilities and keymaps. For example, you can load
                   German keyboard layout like this:

                     loadkeys de

  kernel_modules - kernel modules and 'mdev' hotplug manager.

  kexec_tools -    these tools can be used to boot another kernel and initramfs
                   from userspace.

  libevent       - event notification library API provides a mechanism to
                   execute a callback function when a specific event occurs on
                   a file descriptor or after a timeout has been reached.

  Links          - text-based web browser. Use the 'links' command to activate
                   the browser.

  OpenJDK        - the open source JDK. No need for manual steps. This overlay
                   bundle requires GLIBC and ZLIB.

  Lua            - the Lua Scripting Language. Use the 'lua' command to run an
                   interactive Lua interpreter.

  make           - GNU make utility.

  MLL Hello      - Simple educational overlay bundle with detailed comments
                   for each build step.

  MLL Logo       - custom MLL boot logo.

  MLL Utils      - set of experimental shell scripts (mll-*.sh) which provide
                   additional functionality, e.g. installer and useful tools.
                   This overlay bundle is currently experimental and its build
                   process depends on the host machine.

  MLL Source     - this overlay bundle provides all MLL source code in the
                   directory 'usr/src'.

  nano           - simple command-line text editor with on-screen shortcuts.
                   This overlay bundle requires 'ncurses'.

  ncurses        - 'GUI-like' API that runs within a terminal emulator.

  nweb           - 'nweb' is a very small and easy to use webserver, it runs
                   automatically on port 80. To portforward port 80 from the
                   QEMU guest (minimal) to port 8080 on the host, add
                   '-net nic,model=e1000 -net user,hostfwd=tcp::8080-:80' to
                   'cmd' in the qemu.sh file.

  openjdk        - Free and open-source JDK from OpenJDK.

  static_get     - portable binaries for Linux (http://s.minos.io).

  stress         - simple workload generator. Imposes a configurable amount of
                   CPU, memory, I/O, and disk stress on the system. stress is
                   useful for troubleshooting CPU and RAM issues.

  util_linux     - set of executable utilities distributed by the Linux kernel,
                   similar to busybox or GNU Core Utils. Some packages in this
                   overlay bundle require 'ncurses'.

  vim            - advanced text editor that seeks to provide the power of the
                   de-facto Unix editor 'vi', with a more complete feature set.
                   This package will create symlinks on top of 'vi'.

  vitetris       - console mode tetris game with lots of options. These options
                   are disabled in order to make the game as small as possible.
                   Type 'tetris' in order to start the game.

  ZLIB           - software library used for data compression.

  Zulu JDK       - Zulu is an enterprise quality, certified build of OpenJDK
                   that can be deployed on multiple platforms. Zulu is free to
                   download, use and redistribute. This overlay bundle requires
                   GLIBC and ZLIB.

The overlay bundles can be found in this directory:

  minimal_overlay/bundles

Each overlay bundle can have its own '.config' file. All properties in this
configuration file will override the same properties in the main 'config'
file. Also, each overlay bundle can declare list of bundle dependencies in
the file 'bundle_deps'. The bundles in this file are built before the main
bundle.

The overlay build system is independent from the main build system. However,
some bundles depend on build artifacts from the main build process, so it is
highly recommended to build MLL before you use the overlay build system.

Take a look at the 'mll_hello' overlay bundle for detailed explanation of the
internal overlay system build process and the corresponding directories that
are involved in the process.

You can build all bundles declared in the main '.config' file like this:

  cd minimal_overlay
  ./overlay_build.sh

You can build individual overlay bundle like this:

  cd minimal_overlay
  ./overlay_build.sh mll_hello

You can build more two or more bundles if you separate them with comma:

  cd minimal_overlay
  ./overlay_build.sh mll_hello,dhcp,mll_source

The simplest way to add something to MLL is to put whatever you want in
the following folder:

  minimal_overlay/rootfs

The content of this folder becomes visible at runtime. You can add your
own software or configurations. The content in this folder takes higher
priority which means that you can override everything which is provided
by Minimal Linux Live.

As already mentioned, the main configuration file is '.config'. It is
extensively documented and you can refer to it for detailed information
regarding all configuration properties.

###   ###   ###

I only provide the build scripts. It's entirely up to you to configure and
prepare your build environment. I use Linux Mint and Ubuntu, both 32 and 64 bit
editions. Your distribution might have different build dependencies but most of
the time there is a single meta-package which installs most of the stuff that
you need.

The build process is slow, so be prepared to wait. In the end you should have
the ISO image file 'minimal_linux_live.iso' in the same folder where you
started the build process. You can burn the ISO image on CD/DVD or (better) run
it with PC emulator like QEMU, VirtualBox or VMware Workstation Player.
