# minimal-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**. 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. 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 almost no useful functionality (apart from working shell) and no proper network support. The network support has been handled 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.