# Minimal Linux Script
One script which generates fully functional live Linux ISO image with minimal effort. This is based on the first published version of [Minimal Linux Live](http://github.com/ivandavidov/minimal). All comments and empty lines have been removed and the original script code has been slightly altered to reduce the overall script length.

The script below uses **Linux kernel 3.15.6** and **BusyBox 1.22.1**. The source bundles are downloaded and compiled automatically. If you are using [Ubuntu](http://ubuntu.com) or [Linux Mint](http://linuxmint.com), you should be able to resolve all build dependencies by executing the following command:

    sudo apt-get install wget bc build-essential gawk syslinux genisoimage

After that simply run the below script. It doesn't require root privileges. In the end you should have a bootable ISO image named `minimal_linux_live.iso` in the same directory where you executed the script.

    rm -rf work
    mkdir work
    cd work
    rm -f linux-3.15.6.tar.xz
    wget http://kernel.org/pub/linux/kernel/v3.x/linux-3.15.6.tar.xz
    rm -rf kernel
    mkdir kernel
    tar -xvf linux-3.15.6.tar.xz -C kernel
    cd kernel/linux-3.15.6
    make clean defconfig vmlinux
    cd ../..
    rm -f busybox-1.22.1.tar.bz2
    wget http://busybox.net/downloads/busybox-1.22.1.tar.bz2
    rm -rf busybox
    mkdir busybox
    tar -xvf busybox-1.22.1.tar.bz2 -C busybox
    cd busybox/busybox-1.22.1
    make clean defconfig
    sed -i "s/.*CONFIG_STATIC.*/CONFIG_STATIC=y/" .config
    make busybox install
    rm -rf ../../rootfs
    cp -R _install ../../rootfs
    cd ../../rootfs
    rm -f linuxrc
    mkdir dev etc proc sys tmp
    cd etc
    echo > welcome.txt
    echo '  #####################################' >> welcome.txt
    echo '  #                                   #' >> welcome.txt
    echo '  #  Welcome to "Minimal Linux Live"  #' >> welcome.txt
    echo '  #                                   #' >> welcome.txt
    echo '  #####################################' >> welcome.txt
    echo >> welcome.txt
    cd ..
    echo '#!/bin/sh' > init
    echo 'dmesg -n 1' >> init
    echo 'mount -t devtmpfs none /dev' >> init
    echo 'mount -t proc none /proc' >> init
    echo 'mount -t sysfs none /sys' >> init
    echo 'cat /etc/welcome.txt' >> init
    echo 'while true' >> init
    echo 'do' >> init
    echo '  setsid cttyhack /bin/sh' >> init
    echo 'done' >> init
    echo >> init
    chmod +x init
    rm -f ../rootfs.cpio.gz
    cd ../rootfs
    find . | cpio -H newc -o | gzip > ../rootfs.cpio.gz
    rm -f ../../minimal_linux_live.iso
    cd ../kernel/linux-3.15.6
    make isoimage FDINITRD=../../rootfs.cpio.gz
    cp arch/x86/boot/image.iso ../../../minimal_linux_live.iso
    cd ../../..

Note that this produces very small live Linux OS with working shell and no proper network support. The network support has been implemented properly in the [Minimal Linux Live](http://github.com/ivandavidov/minimal) project which is extensively documented and more feature rich, yet still produces very small live Linux ISO image.