Reorganized the 'experimental' folder. Added 'experimental/musl' whish solves the DNS resolving issue. This should be optimized to use the newly downloaded kernel headers (if possible).

.gitignore

@@ -6,7 +6,11 @@
 /src/work/**
 /src/*.iso
 
-/src/experimental/source/**
+/src/experimental/toybox/source/**
-/src/experimental/work/**
+/src/experimental/toybox/work/**
-/src/experimental/*.iso
+/src/experimental/toybox/*.iso
+
+/src/experimental/musl/source/**
+/src/experimental/musl/work/**
+/src/experimental/musl/*.iso
 

src/experimental/musl/.config

@@ -0,0 +1,18 @@
+# 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 Musl source bundles here:
+#
+# http://musl-libc.org
+#
+MUSL_SOURCE_URL=http://musl-libc.org/releases/musl-1.1.11.tar.gz
+
+# You can find the latest BusyBox source bundles here:
+#
+# http://busybox.net
+#
+BUSYBOX_SOURCE_URL=http://busybox.net/downloads/busybox-1.23.2.tar.bz2
+

src/experimental/musl/00_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/musl/01_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/musl/02_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/musl/03_get_musl.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+
+# Grab everything after the '=' character
+DOWNLOAD_URL=$(grep -i MUSL_SOURCE_URL .config | cut -f2 -d'=')
+
+# Grab everything after the last '/' character
+ARCHIVE_FILE=${DOWNLOAD_URL##*/}
+
+cd source
+
+# Downloading musl file
+# -c option allows the download to resume
+wget -c $DOWNLOAD_URL
+
+# Delete folder with previously extracted musl
+rm -rf ../work/musl
+mkdir ../work/musl
+
+# Extract musl to folder 'work/musl'
+# Full path will be something like 'work/musl/musl-1.1.11'
+tar -xvf $ARCHIVE_FILE -C ../work/musl
+
+cd ..
+

src/experimental/musl/04_build_musl.sh

@@ -0,0 +1,18 @@
+#!/bin/sh
+
+cd work/musl
+
+# Change to the first directory ls finds, e.g. 'musl-1.1.11'
+cd $(ls -d *)
+
+make distclean
+
+mkdir musl-installed
+./configure --prefix=$(pwd)/musl-installed
+
+make -j $(grep ^processor /proc/cpuinfo | wc -l)
+
+make install -j $(grep ^processor /proc/cpuinfo | wc -l)
+
+cd ../../..
+

src/experimental/musl/05_prepare_musl.sh

@@ -0,0 +1,62 @@
+#!/bin/sh
+
+cd work/kernel
+cd $(ls -d *)
+WORK_KERNEL_DIR=$(pwd)
+cd ../../..
+
+cd work/musl
+
+# Change to the first directory ls finds, e.g. 'musl-1.1.11'
+cd $(ls -d *)
+
+cd musl-installed/bin
+
+unlink musl-ar
+ln -s `which ar` musl-ar
+
+unlink musl-strip
+ln -s `which strip` musl-strip
+
+cd ../include
+
+#
+# Should work with headers from the newly downloaded kernel
+# but it diesn't work. Damn!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+#
+#unlink linux
+#ln -s $WORK_KERNEL_DIR/include/linux linux
+#
+#unlink mtd
+#ln -s $WORK_KERNEL_DIR/include/linux/mtd mtd
+#
+#unlink asm
+#ln -s $WORK_KERNEL_DIR/include/uapi/asm-generic asm
+#
+#unlink asm-generic
+#ln -s $WORK_KERNEL_DIR/include/uapi/asm-generic asm-generic
+#
+#unlink uapi
+#ln -s $WORK_KERNEL_DIR/include/uapi uapi
+#
+#unlink uapi
+#ln -s $WORK_KERNEL_DIR/include/uapi uapi
+
+unlink linux
+ln -s /usr/include/linux linux
+
+unlink mtd
+ln -s /usr/include/mtd mtd
+
+if [ -d /usr/include/asm ]
+then
+  unlink asm
+  ln -s /usr/include/asm asm
+else
+  unlink asm
+  ln -s /usr/include/asm-generic asm
+fi
+
+unlink asm-generic
+ln -s /usr/include/asm-generic asm-generic
+

src/experimental/musl/06_get_busybox.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+
+# Grab everything after the '=' character
+DOWNLOAD_URL=$(grep -i BUSYBOX_SOURCE_URL .config | cut -f2 -d'=')
+
+# Grab everything after the last '/' character
+ARCHIVE_FILE=${DOWNLOAD_URL##*/}
+
+cd source
+
+# Downloading busybox source
+# -c option allows the download to resume
+wget -c $DOWNLOAD_URL
+
+# Delete folder with previously extracted busybox
+rm -rf ../work/busybox
+mkdir ../work/busybox
+
+# Extract busybox to folder 'busybox'
+# Full path will be something like 'work/busybox/busybox-1.23.1'
+tar -xvf $ARCHIVE_FILE -C ../work/busybox
+
+cd ..
+

src/experimental/musl/07_build_busybox.sh

@@ -0,0 +1,41 @@
+#!/bin/sh
+
+cd work/musl
+cd $(ls -d *)
+cd musl-installed
+cd bin
+MUSL_BIN_DIR=$(pwd)
+cd ../../../../..
+
+cd work/busybox
+
+# Change to the first directory ls finds, e.g. 'busybox-1.23.1'
+cd $(ls -d *)
+
+PATH_BACKUP=$PATH
+PATH=$MUSL_BIN_DIR:$PATH
+
+# Remove previously generated artifacts
+make distclean
+
+# Create a default configuration file
+make defconfig
+
+# Change the configuration, so that busybox is statically compiled
+# You could do this manually with 'make menuconfig'
+sed -i "s/.*CONFIG_STATIC.*/CONFIG_STATIC=y/" .config
+sed -i "s/.*CONFIG_CROSS_COMPILER_PREFIX.*/CONFIG_CROSS_COMPILER_PREFIX=\"musl-\"/" .config
+sed -i "s/.*CONFIG_IFPLUGD.*/CONFIG_IFPLUGD=n/" .config
+sed -i "s/.*CONFIG_INETD.*/CONFIG_INETD=n/" .config
+
+# Compile busybox with optimization for "parallel jobs" = "number of processors"
+make busybox -j $(grep ^processor /proc/cpuinfo | wc -l)
+
+# Create the symlinks for busybox
+# It uses the file 'busybox.links' for this
+make install
+
+PATH=$PATH_BACKUP
+
+cd ../../..
+

src/experimental/musl/08_generate_rootfs.sh

@@ -0,0 +1,123 @@
+#!/bin/sh
+
+cd work
+
+rm -rf rootfs
+
+cd busybox
+cd $(ls -d *)
+
+# Copy all BusyBox generated stuff to the location of our "initramfs" folder.
+cp -R _install ../../rootfs
+cd ../../rootfs
+
+# Remove "linuxrc" which is used when we boot in "RAM disk" mode. 
+rm -f linuxrc
+
+# 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 script "/etc/bootscript.sh" is automatically executed as part of the
+# "init" proess. We suppress most kernel messages, mount all crytical file
+# systems, loop through all available network devices and we configure them
+# through DHCP.
+cat > bootscript.sh << EOF
+#!/bin/sh
+
+dmesg -n 1
+mount -t devtmpfs none /dev
+mount -t proc none /proc
+mount -t sysfs none /sys
+
+for DEVICE in /sys/class/net/* ; do
+  ip link set \${DEVICE##*/} up
+  [ \${DEVICE##*/} != lo ] && udhcpc -b -i \${DEVICE##*/} -s /etc/rc.dhcp
+done
+
+EOF
+
+chmod +x bootscript.sh
+
+# The script "/etc/rc.dhcp" is automatically invoked for each network device. 
+cat > rc.dhcp << EOF
+#!/bin/sh
+
+ip addr add \$ip/\$mask dev \$interface
+
+if [ "\$router" ]; then
+  ip route add default via \$router dev \$interface
+fi
+
+EOF
+
+chmod +x rc.dhcp
+
+# DNS resolving is done by using Google's public DNS servers
+cat > resolv.conf << EOF
+nameserver 8.8.8.8
+nameserver 8.8.4.4
+
+EOF
+
+# 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
+
+# The file "/etc/inittab" contains the configuration which defines how the
+# system will be initialized. Check the following URL for more details:
+# http://git.busybox.net/busybox/tree/examples/inittab
+cat > inittab << EOF
+::sysinit:/etc/bootscript.sh
+::restart:/sbin/init
+::ctrlaltdel:/sbin/reboot
+::once:cat /etc/welcome.txt
+::respawn:/bin/cttyhack /bin/sh
+tty2::once:cat /etc/welcome.txt
+tty2::respawn:/bin/sh
+tty3::once:cat /etc/welcome.txt
+tty3::respawn:/bin/sh
+tty4::once:cat /etc/welcome.txt
+tty4::respawn:/bin/sh
+
+EOF
+
+cd ..
+
+# The "/init" script passes the execution to "/sbin/init" which in turn looks
+# for the configuration file "/etc/inittab".
+cat > init << EOF
+#!/bin/sh
+
+exec /sbin/init
+
+EOF
+
+chmod +x 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/musl/build_minimal_linux_live.sh

@@ -0,0 +1,14 @@
+#!/bin/sh
+
+sh 00_prepare.sh
+sh 01_get_kernel.sh
+sh 02_build_kernel.sh
+sh 03_get_musl.sh
+sh 04_build_musl.sh
+sh 05_prepare_musl.sh
+sh 06_get_busybox.sh
+sh 07_build_busybox.sh
+sh 08_generate_rootfs.sh
+sh 09_pack_rootfs.sh
+sh 10_generate_iso.sh
+

src/experimental/toybox/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/toybox/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/toybox/qemu32.sh

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

src/experimental/toybox/qemu64.sh

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