Added experimental scripts which build Kernel + ToyBox with simple DHCP network. DNS is still broken due to glibc issues.

src/experimental/.config

@@ -0,0 +1,12 @@
+# You can find the latest Linux kernel source bundles here:
+#
+# http://kernel.org
+#
+KERNEL_SOURCE_URL=https://www.kernel.org/pub/linux/kernel/v4.x/linux-4.1.6.tar.xz
+
+# You can find the latest BusyBox source bundles here:
+#
+# http://busybox.net
+#
+TOYBOX_SOURCE_URL=http://landley.net/toybox/downloads/toybox-0.6.0.tar.gz
+

src/experimental/0_prepare.sh

@@ -0,0 +1,8 @@
+#!/bin/sh
+
+rm -rf work
+mkdir work
+
+# -p stops errors if the directory already exists
+mkdir -p source
+

src/experimental/1_get_kernel.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+
+# Grab everything after the '=' character
+DOWNLOAD_URL=$(grep -i KERNEL_SOURCE_URL .config | cut -f2 -d'=')
+
+# Grab everything after the last '/' character
+ARCHIVE_FILE=${DOWNLOAD_URL##*/}
+
+cd source
+
+# Downloading kernel file
+# -c option allows the download to resume
+wget -c $DOWNLOAD_URL
+
+# Delete folder with previously extracted kernel
+rm -rf ../work/kernel
+mkdir ../work/kernel
+
+# Extract kernel to folder 'work/kernel'
+# Full path will be something like 'work/kernel/linux-3.16.1'
+tar -xvf $ARCHIVE_FILE -C ../work/kernel
+
+cd ..
+

src/experimental/2_build_kernel.sh

@@ -0,0 +1,23 @@
+#!/bin/sh
+
+cd work/kernel
+
+# Change to the first directory ls finds, e.g. 'linux-3.18.6'
+cd $(ls -d *)
+
+# Cleans up the kernel sources, including configuration files
+make mrproper
+
+# Create a default configuration file for the kernel
+make defconfig
+
+# Changes the name of the system
+sed -i "s/.*CONFIG_DEFAULT_HOSTNAME.*/CONFIG_DEFAULT_HOSTNAME=\"minimal\"/" .config
+
+# Compile the kernel with optimization for "parallel jobs" = "number of processors"
+# Good explanation of the different kernels
+# http://unix.stackexchange.com/questions/5518/what-is-the-difference-between-the-following-kernel-makefile-terms-vmlinux-vmlinux
+make bzImage -j $(grep ^processor /proc/cpuinfo | wc -l)
+
+cd ../../..
+

src/experimental/3_get_toybox.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+
+# Grab everything after the '=' character
+DOWNLOAD_URL=$(grep -i TOYBOX_SOURCE_URL .config | cut -f2 -d'=')
+
+# Grab everything after the last '/' character
+ARCHIVE_FILE=${DOWNLOAD_URL##*/}
+
+cd source
+
+# Downloading toybox source
+# -c option allows the download to resume
+wget -c $DOWNLOAD_URL
+
+# Delete folder with previously extracted toybox
+rm -rf ../work/toybox
+mkdir ../work/toybox
+
+# Extract toybox to folder 'toybox'
+# Full path will be something like 'work/toybox/toybox-0.6.0'
+tar -xvf $ARCHIVE_FILE -C ../work/toybox
+
+cd ..
+

src/experimental/4_build_toybox.sh

@@ -0,0 +1,29 @@
+#!/bin/sh
+
+cd work/toybox
+
+# Change to the first directory ls finds, e.g. 'toybox-0.6.0'
+cd $(ls -d *)
+
+# Remove previously generated artefacts
+make distclean
+
+# Create a default configuration file
+make allyesconfig
+
+export LDFLAGS="--static"
+
+# Compile toybox with optimization for "parallel jobs" = "number of processors"
+make toybox -j $(grep ^processor /proc/cpuinfo | wc -l)
+
+unset LDFLAGS
+
+rm -rf rootfs
+mkdir rootfs
+export PREFIX=rootfs
+# Create the symlinks for toybox
+make install_flat
+unset PREFIX
+
+cd ../../..
+

src/experimental/5_generate_rootfs.sh

@@ -0,0 +1,71 @@
+#!/bin/sh
+
+cd work
+
+rm -rf rootfs
+mkdir rootfs
+
+cd toybox
+cd $(ls -d *)
+
+# Copy all toybox generated stuff to the location of our "initramfs" folder.
+cp -R rootfs ../../rootfs/bin
+cd ../../rootfs
+
+# Create root FS folders
+mkdir dev
+mkdir etc
+mkdir proc
+mkdir root
+mkdir src
+mkdir sys
+mkdir tmp
+
+# "1" means that only the owner of a file/directory (or root) can remove it.
+chmod 1777 tmp
+
+cd etc
+
+# The file "/etc/welcome.txt" is displayed on every boot of the system in each
+# available terminal.
+cat > welcome.txt << EOF
+
+  #####################################
+  #                                   #
+  #  Welcome to "Minimal Linux Live"  #
+  #                                   #
+  #####################################
+
+EOF
+
+cd ..
+
+# Problem setting default path
+cat > init << EOF
+#!/bin/sh
+dmesg -n 1
+
+mount -t devtmpfs none /dev
+mount -t proc none /proc
+mount -t sysfs none /sys
+
+ifconfig eth0 up
+dhcp -i eth0
+
+cat /etc/welcome.txt
+
+sh
+
+poweroff
+EOF
+
+chmod +rx init
+
+# Copy all source files to "/src". Note that the scripts won't work there.
+cp ../../*.sh src
+cp ../../.config src
+chmod +r src/*.sh
+chmod +r src/.config
+
+cd ../..
+

src/experimental/6_pack_rootfs.sh

@@ -0,0 +1,14 @@
+#!/bin/sh
+
+cd work
+
+# Remove the old initramfs archive if it exists.
+rm -f rootfs.cpio.gz
+
+cd rootfs
+
+# Packs the current folder structure in "cpio.gz" archive.
+find . | cpio -H newc -o | gzip > ../rootfs.cpio.gz
+
+cd ../..
+

src/experimental/7_generate_iso.sh

@@ -0,0 +1,19 @@
+#!/bin/sh
+
+rm -f minimal_linux_live.iso
+
+cd work/kernel
+cd $(ls -d *)
+
+# Edit Makefile to look for genisoimage instead of mkisofs. This was added as a
+# workaround for some "Debian" and "Arch Linux" distributions. In general this
+# fix should be harmless. 
+sed -i 's/mkisofs/genisoimage/g' arch/x86/boot/Makefile
+
+# Generate the ISO image with optimization for "parallel jobs" = "number of processors"
+make isoimage FDINITRD=../../rootfs.cpio.gz -j $(grep ^processor /proc/cpuinfo | wc -l)
+
+cp arch/x86/boot/image.iso ../../../minimal_linux_live.iso
+
+cd ../../..
+

src/experimental/build_minimal_linux_live.sh

@@ -0,0 +1,10 @@
+#!/bin/sh
+
+sh 0_prepare.sh
+sh 1_get_kernel.sh
+sh 2_build_kernel.sh
+sh 3_get_busybox.sh
+sh 4_build_busybox.sh
+sh 5_generate_rootfs.sh
+sh 6_pack_rootfs.sh
+sh 7_generate_iso.sh

src/experimental/qemu32.sh

@@ -0,0 +1,4 @@
+#!/bin/sh
+
+qemu-system-i386 -cdrom minimal_linux_live.iso
+

src/experimental/qemu64.sh

@@ -0,0 +1,4 @@
+#!/bin/sh
+
+qemu-system-x86_64 -cdrom minimal_linux_live.iso
+