Added ENABLE_SPLITFS option to produce distinct /boot/firmware and root images

15 files changed, 589 insertions, 433 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..445d7b0
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+images
+custom.d
+*.swp
diff --git a/README.md b/README.md
index 40c68f7..f4117dd 100644
--- a/README.md
+++ b/README.md
@@ -123,7 +123,7 @@ Install Xorg open-source X Window System.
 ##### `ENABLE_WM`=""
 Install a user defined window manager for the X Window System. To make sure all X related package dependencies are getting installed `ENABLE_XORG` will automatically get enabled if `ENABLE_WM` is used. The `rpi2-gen-image.sh` script has been tested with the following list of window managers: `blackbox`, `openbox`, `fluxbox`, `jwm`, `dwm`, `xfce4`, `awesome`.
 
-#### Advanced sytem features:
+#### Advanced system features:
 ##### `ENABLE_MINBASE`=false
 Use debootstrap script variant `minbase` which only includes essential packages and apt. This will reduce the disk usage by about 65 MB.
 
@@ -155,6 +155,43 @@ Enable having root partition on an USB drive by creating two image files: one fo
 ##### `CHROOT_SCRIPTS`=""
 Path to a directory with scripts that should be run in the chroot before the image is finally built. Every executable file in this direcory is run in lexicographical order.
 
+#### Kernel compilation:
+##### `BUILD_KERNEL`=false
+Build and install the latest RPi2 linux kernel. Currently only the default RPi2 kernel configuration is used. Detailed configuration parameters for customizing the kernel and minor bug fixes still need to get implemented. feel free to help.
+
+##### `KERNEL_HEADERS`=true
+If true, also install kernel headers with built kernel.
+
+## Understanding the script
+The functions of this script that are required for the different stages of the bootstrapping are split up into single files located inside the `bootstrap.d` directory. During the bootstrapping every script in this directory gets executed in lexicographical order:
+
+| Script | Description |
+| --- | --- |
+| `10-bootstrap.sh` | Debootstrap basic system |
+| `11-apt.sh` | Setup APT repositories |
+| `12-locale.sh` | Setup Locales and keyboard settings |
+| `13-kernel.sh` | Build and install RPi2 Kernel |
+| `20-networking.sh` | Setup Networking |
+| `21-firewall.sh` | Setup iptables Firewall |
+| `30-security.sh` | Setup users and security settings |
+| `31-logging.sh` | Setup logging |
+| `41-uboot.sh` | Build and Setup Uboot |
+| `42-fbturbo.sh` | Buld and Setup fbturbo Xorg driver |
+| `50-firstboot.sh` | First boot actions |
+
+All the required configuration files that will be copied to the generated OS image are located inside the `files` directory. It is not recommended to modify these configuration files manually.
+
+| Directory | Description |
+| --- | --- |
+| `boot` | Boot and RPi2 configuration files |
+| `firstboot` | Scripts that get executed on first boot  |
+| `iptables` | Firewall configuration files |
+| `modprobe.d` | Kernel Module Blacklist configuration |
+| `mount` | Fstab configuration |
+| `network` | Networking configuration files |
+| `sysctl.d` | Swapping and Network Hardening configuration |
+| `xorg` | fbturbo Xorg driver configuration |
+
 ## Logging of the bootstrapping process
 All information related to the bootstrapping process and the commands executed by the `rpi2-gen-image.sh` script can easily be saved into a logfile. The common shell command `script` can be used for this purpose:
 
diff --git a/bootstrap.d/10-bootstrap.sh b/bootstrap.d/10-bootstrap.sh
new file mode 100644
index 0000000..fdccfba
--- /dev/null
+++ b/bootstrap.d/10-bootstrap.sh
@@ -0,0 +1,27 @@
+#
+# Debootstrap basic system
+#
+
+. ./functions.sh
+
+# Base debootstrap (unpack only)
+if [ "$ENABLE_MINBASE" = true ] ; then
+  http_proxy=${APT_PROXY} debootstrap --arch=armhf --variant=minbase --foreign --include=${APT_INCLUDES} $RELEASE $R http://${APT_SERVER}/debian
+else
+  http_proxy=${APT_PROXY} debootstrap --arch=armhf --foreign --include=${APT_INCLUDES} $RELEASE $R http://${APT_SERVER}/debian
+fi
+
+# Copy qemu emulator binary to chroot
+cp /usr/bin/qemu-arm-static $R/usr/bin
+
+# Copy debian-archive-keyring.pgp
+mkdir -p $R/usr/share/keyrings
+cp /usr/share/keyrings/debian-archive-keyring.gpg $R/usr/share/keyrings/debian-archive-keyring.gpg
+
+# Complete the bootstrapping process
+chroot_exec /debootstrap/debootstrap --second-stage
+
+# Mount required filesystems
+mount -t proc none $R/proc
+mount -t sysfs none $R/sys
+mount --bind /dev/pts $R/dev/pts
diff --git a/bootstrap.d/11-apt.sh b/bootstrap.d/11-apt.sh
new file mode 100644
index 0000000..9a4739d
--- /dev/null
+++ b/bootstrap.d/11-apt.sh
@@ -0,0 +1,40 @@
+#
+# Setup APT repositories
+#
+
+. ./functions.sh
+
+# Use proxy inside chroot
+if [ -z "$APT_PROXY" ] ; then
+  echo "Acquire::http::Proxy \"$APT_PROXY\";" >> $R/etc/apt/apt.conf.d/10proxy
+fi
+
+# Pin package flash-kernel to repositories.collabora.co.uk
+cat <<EOM >$R/etc/apt/preferences.d/flash-kernel
+Package: flash-kernel
+Pin: origin repositories.collabora.co.uk
+Pin-Priority: 1000
+EOM
+
+# Upgrade collabora package index and install collabora keyring
+echo "deb https://repositories.collabora.co.uk/debian ${RELEASE} rpi2" >$R/etc/apt/sources.list
+chroot_exec apt-get -qq -y update
+chroot_exec apt-get -qq -y --force-yes install collabora-obs-archive-keyring
+
+# Set up initial sources.list
+cat <<EOM >$R/etc/apt/sources.list
+deb http://${APT_SERVER}/debian ${RELEASE} main contrib
+#deb-src http://${APT_SERVER}/debian ${RELEASE} main contrib
+
+deb http://${APT_SERVER}/debian/ ${RELEASE}-updates main contrib
+#deb-src http://${APT_SERVER}/debian/ ${RELEASE}-updates main contrib
+
+deb http://security.debian.org/ ${RELEASE}/updates main contrib
+#deb-src http://security.debian.org/ ${RELEASE}/updates main contrib
+
+deb https://repositories.collabora.co.uk/debian ${RELEASE} rpi2
+EOM
+
+# Upgrade package index and update all installed packages and changed dependencies
+chroot_exec apt-get -qq -y update
+chroot_exec apt-get -qq -y -u dist-upgrade
diff --git a/bootstrap.d/12-locale.sh b/bootstrap.d/12-locale.sh
new file mode 100644
index 0000000..de1ecc9
--- /dev/null
+++ b/bootstrap.d/12-locale.sh
@@ -0,0 +1,52 @@
+#
+# Setup locales and keyboard settings
+#
+
+. ./functions.sh
+
+# Set up timezone
+echo ${TIMEZONE} >$R/etc/timezone
+chroot_exec dpkg-reconfigure -f noninteractive tzdata
+
+# Set up default locale and keyboard configuration
+if [ "$ENABLE_MINBASE" = false ] ; then
+  # Set locale choice in debconf db, even though dpkg-reconfigure ignores and overwrites them due to some bug
+  # https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=684134 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=685957
+  # ... so we have to set locales manually
+  if [ "$DEFLOCAL" = "en_US.UTF-8" ] ; then
+    chroot_exec echo "locales locales/locales_to_be_generated multiselect ${DEFLOCAL} UTF-8" | debconf-set-selections
+  else
+    # en_US.UTF-8 should be available anyway : https://www.debian.org/doc/manuals/debian-reference/ch08.en.html#_the_reconfiguration_of_the_locale
+    chroot_exec echo "locales locales/locales_to_be_generated multiselect en_US.UTF-8 UTF-8, ${DEFLOCAL} UTF-8" | debconf-set-selections
+    chroot_exec sed -i "/en_US.UTF-8/s/^#//" /etc/locale.gen
+  fi
+  chroot_exec sed -i "/${DEFLOCAL}/s/^#//" /etc/locale.gen
+  chroot_exec echo "locales locales/default_environment_locale select ${DEFLOCAL}" | debconf-set-selections
+  chroot_exec locale-gen
+  chroot_exec update-locale LANG=${DEFLOCAL}
+
+  # Keyboard configuration, if requested
+  if [ "$XKBMODEL" != "" ] ; then
+    chroot_exec sed -i "s/^XKBMODEL.*/XKBMODEL=\"${XKBMODEL}\"/" /etc/default/keyboard
+  fi
+  if [ "$XKBLAYOUT" != "" ] ; then
+    chroot_exec sed -i "s/^XKBLAYOUT.*/XKBLAYOUT=\"${XKBLAYOUT}\"/" /etc/default/keyboard
+  fi
+  if [ "$XKBVARIANT" != "" ] ; then
+    chroot_exec sed -i "s/^XKBVARIANT.*/XKBVARIANT=\"${XKBVARIANT}\"/" /etc/default/keyboard
+  fi
+  if [ "$XKBOPTIONS" != "" ] ; then
+    chroot_exec sed -i "s/^XKBOPTIONS.*/XKBOPTIONS=\"${XKBOPTIONS}\"/" /etc/default/keyboard
+  fi
+  chroot_exec dpkg-reconfigure -f noninteractive keyboard-configuration
+  # Set up font console
+  case "${DEFLOCAL}" in
+    *UTF-8)
+      chroot_exec sed -i 's/^CHARMAP.*/CHARMAP="UTF-8"/' /etc/default/console-setup
+      ;;
+    *)
+      chroot_exec sed -i 's/^CHARMAP.*/CHARMAP="guess"/' /etc/default/console-setup
+      ;;
+  esac
+  chroot_exec dpkg-reconfigure -f noninteractive console-setup
+fi
diff --git a/bootstrap.d/13-kernel.sh b/bootstrap.d/13-kernel.sh
new file mode 100644
index 0000000..a5c379e
--- /dev/null
+++ b/bootstrap.d/13-kernel.sh
@@ -0,0 +1,109 @@
+#
+# Kernel installation
+#
+
+. ./functions.sh
+
+# Fetch and build latest raspberry kernel
+if [ "$BUILD_KERNEL" = true ] ; then
+  # Fetch current raspberrypi kernel sources
+  git -C $R/usr/local/src clone --depth=1 https://github.com/raspberrypi/linux
+
+  # Load default raspberry kernel configuration
+  make -C $R/usr/local/src/linux ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- bcm2709_defconfig
+
+  # Cross compile kernel and modules
+  make -C $R/usr/local/src/linux -j$(grep -c processor /proc/cpuinfo) ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- zImage modules dtbs
+
+  # Install kernel modules
+  make -C $R/usr/local/src/linux ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- INSTALL_MOD_PATH=../.. modules_install
+
+  # Install kernel headers
+  if [ "$KERNEL_HEADERS" = true ]; then
+    make -C $R/usr/local/src/linux ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- INSTALL_HDR_PATH=../../usr headers_install
+  fi
+
+  # Copy and rename compiled kernel to boot directory
+  mkdir $R/boot/firmware/
+  $R/usr/local/src/linux/scripts/mkknlimg $R/usr/local/src/linux/arch/arm/boot/zImage $R/boot/firmware/kernel7.img
+
+  # Copy dts and dtb device definitions
+  mkdir $R/boot/firmware/overlays/
+  cp $R/usr/local/src/linux/arch/arm/boot/dts/*.dtb $R/boot/firmware/
+  cp $R/usr/local/src/linux/arch/arm/boot/dts/overlays/*.dtb* $R/boot/firmware/overlays/
+  cp $R/usr/local/src/linux/arch/arm/boot/dts/overlays/README $R/boot/firmware/overlays/
+
+  # Install raspberry bootloader and flash-kernel
+  chroot_exec apt-get -qq -y --no-install-recommends install raspberrypi-bootloader-nokernel
+else
+  # Kernel installation
+  chroot_exec apt-get -qq -y --no-install-recommends install linux-image-${KERNEL} raspberrypi-bootloader-nokernel
+
+  # Install flash-kernel last so it doesn't try (and fail) to detect the platform in the chroot
+  chroot_exec apt-get -qq -y install flash-kernel
+
+  VMLINUZ="$(ls -1 $R/boot/vmlinuz-* | sort | tail -n 1)"
+  [ -z "$VMLINUZ" ] && exit 1
+  cp $VMLINUZ $R/boot/firmware/kernel7.img
+fi
+
+# Set up firmware boot cmdline
+if [ "$ENABLE_SPLITFS" = true ] ; then
+  CMDLINE="dwc_otg.lpm_enable=0 root=/dev/sda1 rootfstype=ext4 rootflags=commit=100,data=writeback elevator=deadline rootwait net.ifnames=1 console=tty1 ${CMDLINE}"
+else
+  CMDLINE="dwc_otg.lpm_enable=0 root=/dev/mmcblk0p2 rootfstype=ext4 rootflags=commit=100,data=writeback elevator=deadline rootwait net.ifnames=1 console=tty1 ${CMDLINE}"
+fi
+
+# Set up serial console support (if requested)
+if [ "$ENABLE_CONSOLE" = true ] ; then
+  CMDLINE="${CMDLINE} console=ttyAMA0,115200 kgdboc=ttyAMA0,115200"
+fi
+
+# Set up IPv6 networking support
+if [ "$ENABLE_IPV6" = false ] ; then
+  CMDLINE="${CMDLINE} ipv6.disable=1"
+fi
+
+echo "${CMDLINE}" >$R/boot/firmware/cmdline.txt
+
+# Set up firmware config
+install -o root -g root -m 644 files/config.txt $R/boot/firmware/config.txt
+
+# Load snd_bcm2835 kernel module at boot time
+if [ "$ENABLE_SOUND" = true ] ; then
+  echo "snd_bcm2835" >>$R/etc/modules
+fi
+
+# Set smallest possible GPU memory allocation size: 16MB (no X)
+if [ "$ENABLE_MINGPU" = true ] ; then
+  echo "gpu_mem=16" >>$R/boot/firmware/config.txt
+fi
+
+# Create symlinks
+ln -sf firmware/config.txt $R/boot/config.txt
+ln -sf firmware/cmdline.txt $R/boot/cmdline.txt
+
+# Prepare modules-load.d directory
+mkdir -p $R/lib/modules-load.d/
+
+# Load random module on boot
+if [ "$ENABLE_HWRANDOM" = true ] ; then
+  cat <<EOM >$R/lib/modules-load.d/rpi2.conf
+bcm2708_rng
+EOM
+fi
+
+# Prepare modprobe.d directory
+mkdir -p $R/etc/modprobe.d/
+
+# Blacklist sound modules
+install -o root -g root -m 644 files/modprobe.d/raspi-blacklist.conf $R/etc/modprobe.d/raspi-blacklist.conf
+
+# Create default fstab
+install -o root -g root -m 644 files/fstab $R/etc/fstab
+if [ "$ENABLE_SPLITFS" = true ] ; then
+  sed -i 's/mmcblk0p2/sda1/' $R/etc/fstab
+fi
+
+# Avoid swapping and increase cache sizes
+install -o root -g root -m 644 files/sysctl.d/81-rpi-vm.conf $R/etc/sysctl.d/81-rpi-vm.conf
diff --git a/bootstrap.d/20-networking.sh b/bootstrap.d/20-networking.sh
new file mode 100644
index 0000000..9390033
--- /dev/null
+++ b/bootstrap.d/20-networking.sh
@@ -0,0 +1,78 @@
+#
+# Setup networking
+#
+
+. ./functions.sh
+
+# Set up IPv4 hosts
+echo ${HOSTNAME} >$R/etc/hostname
+cat <<EOM >$R/etc/hosts
+127.0.0.1       localhost
+127.0.1.1       ${HOSTNAME}
+EOM
+
+if [ "$NET_ADDRESS" != "" ] ; then
+NET_IP=$(echo ${NET_ADDRESS} | cut -f 1 -d'/')
+sed -i "s/^127.0.1.1/${NET_IP}/" $R/etc/hosts
+fi
+
+# Set up IPv6 hosts
+if [ "$ENABLE_IPV6" = true ] ; then
+cat <<EOM >>$R/etc/hosts
+
+::1             localhost ip6-localhost ip6-loopback
+ff02::1         ip6-allnodes
+ff02::2         ip6-allrouters
+EOM
+fi
+
+# Place hint about network configuration
+cat <<EOM >$R/etc/network/interfaces
+# Debian switched to systemd-networkd configuration files.
+# please configure your networks in '/etc/systemd/network/'
+source /etc/interfaces.d/*.conf
+EOM
+
+if [ "$ENABLE_DHCP" = true ] ; then
+# Enable systemd-networkd DHCP configuration for interface eth0
+cat <<EOM >$R/etc/systemd/network/eth.network
+[Match]
+Name=eth0
+
+[Network]
+DHCP=yes
+EOM
+
+# Set DHCP configuration to IPv4 only
+if [ "$ENABLE_IPV6" = false ] ; then
+  sed -i "s/^DHCP=yes/DHCP=v4/" $R/etc/systemd/network/eth.network
+fi
+else # ENABLE_DHCP=false
+cat <<EOM >$R/etc/systemd/network/eth.network
+[Match]
+Name=eth0
+
+[Network]
+DHCP=no
+Address=${NET_ADDRESS}
+Gateway=${NET_GATEWAY}
+DNS=${NET_DNS_1}
+DNS=${NET_DNS_2}
+Domains=${NET_DNS_DOMAINS}
+NTP=${NET_NTP_1}
+NTP=${NET_NTP_2}
+EOM
+fi
+
+# Enable systemd-networkd service
+chroot_exec systemctl enable systemd-networkd
+
+# Enable network stack hardening
+if [ "$ENABLE_HARDNET" = true ] ; then
+  install -o root -g root -m 644 files/sysctl.d/82-rpi-net-hardening.conf $R/etc/sysctl.d/82-rpi-net-hardening.conf
+
+# Enable resolver warnings about spoofed addresses
+  cat <<EOM >>$R/etc/host.conf
+spoof warn
+EOM
+fi
diff --git a/bootstrap.d/21-firewall.sh b/bootstrap.d/21-firewall.sh
new file mode 100644
index 0000000..5563d06
--- /dev/null
+++ b/bootstrap.d/21-firewall.sh
@@ -0,0 +1,43 @@
+#
+# Enable firewall based on iptables started by systemd service
+#
+
+. ./functions.sh
+
+if [ "$ENABLE_IPTABLES" = true ] ; then
+  # Create iptables configuration directory
+  mkdir -p "$R/etc/iptables"
+
+  # Create iptables systemd service
+  install -o root -g root -m 644 files/iptables/iptables.service $R/etc/systemd/system/iptables.service
+
+  # Create flush-table script called by iptables service
+  install -o root -g root -m 755 files/iptables/flush-iptables.sh $R/etc/iptables/flush-iptables.sh
+
+  # Create iptables rule file
+  install -o root -g root -m 644 files/iptables/iptables.rules $R/etc/iptables/iptables.rules
+
+  # Reload systemd configuration and enable iptables service
+  chroot_exec systemctl daemon-reload
+  chroot_exec systemctl enable iptables.service
+
+  if [ "$ENABLE_IPV6" = true ] ; then
+    # Create ip6tables systemd service
+    install -o root -g root -m 644 files/iptables/ip6tables.service $R/etc/systemd/system/ip6tables.service
+
+    # Create ip6tables file
+    install -o root -g root -m 755 files/iptables/flush-ip6tables.sh $R/etc/iptables/flush-ip6tables.sh
+
+    install -o root -g root -m 644 files/iptables/ip6tables.rules $R/etc/iptables/ip6tables.rules
+
+    # Reload systemd configuration and enable iptables service
+    chroot_exec systemctl daemon-reload
+    chroot_exec systemctl enable ip6tables.service
+  fi
+fi
+
+# Remove SSHD related iptables rules
+if [ "$ENABLE_SSHD" = false ] ; then
+ sed -e '/^#/! {/SSH/ s/^/# /}' -i $R/etc/iptables/iptables.rules 2> /dev/null
+ sed -e '/^#/! {/SSH/ s/^/# /}' -i $R/etc/iptables/ip6tables.rules 2> /dev/null
+fi
diff --git a/bootstrap.d/30-security.sh b/bootstrap.d/30-security.sh
new file mode 100644
index 0000000..31aa782
--- /dev/null
+++ b/bootstrap.d/30-security.sh
@@ -0,0 +1,30 @@
+#
+# Setup users and security settings
+#
+
+. ./functions.sh
+
+# Generate crypt(3) password string
+ENCRYPTED_PASSWORD=`mkpasswd -m sha-512 ${PASSWORD}`
+
+# Set up default user
+if [ "$ENABLE_USER" = true ] ; then
+  chroot_exec adduser --gecos pi --add_extra_groups --disabled-password pi
+  chroot_exec usermod -a -G sudo -p "${ENCRYPTED_PASSWORD}" pi
+fi
+
+# Set up root password or not
+if [ "$ENABLE_ROOT" = true ]; then
+  chroot_exec usermod -p "${ENCRYPTED_PASSWORD}" root
+
+  if [ "$ENABLE_ROOT_SSH" = true ]; then
+    sed -i 's|[#]*PermitRootLogin.*|PermitRootLogin yes|g' $R/etc/ssh/sshd_config
+  fi
+else
+  chroot_exec usermod -p \'!\' root
+fi
+
+# Enable serial console systemd style
+if [ "$ENABLE_CONSOLE" = true ] ; then
+  chroot_exec systemctl enable serial-getty\@ttyAMA0.service
+fi
diff --git a/bootstrap.d/31-logging.sh b/bootstrap.d/31-logging.sh
new file mode 100644
index 0000000..a09e623
--- /dev/null
+++ b/bootstrap.d/31-logging.sh
@@ -0,0 +1,12 @@
+#
+# Setup logging
+#
+
+. ./functions.sh
+
+# Disable rsyslog
+if [ "$ENABLE_RSYSLOG" = false ]; then
+  sed -i 's|[#]*ForwardToSyslog=yes|ForwardToSyslog=no|g' $R/etc/systemd/journald.conf
+  chroot_exec systemctl disable rsyslog
+  chroot_exec apt-get purge -q -y --force-yes rsyslog
+fi
diff --git a/bootstrap.d/41-uboot.sh b/bootstrap.d/41-uboot.sh
new file mode 100644
index 0000000..507be55
--- /dev/null
+++ b/bootstrap.d/41-uboot.sh
@@ -0,0 +1,44 @@
+#
+# Setup Uboot
+#
+
+. ./functions.sh
+
+# Install gcc/c++ build environment inside the chroot
+if [ "$ENABLE_UBOOT" = true ] || [ "$ENABLE_FBTURBO" = true ]; then
+  chroot_exec apt-get install -q -y --force-yes --no-install-recommends linux-compiler-gcc-4.9-arm g++ make bc
+fi
+
+# Fetch and build U-Boot bootloader
+if [ "$ENABLE_UBOOT" = true ] ; then
+  # Fetch U-Boot bootloader sources
+  git -C $R/tmp clone git://git.denx.de/u-boot.git
+
+  # Build and install U-Boot inside chroot
+  chroot_exec make -C /tmp/u-boot/ rpi_2_defconfig all
+
+  # Copy compiled bootloader binary and set config.txt to load it
+  cp $R/tmp/u-boot/u-boot.bin $R/boot/firmware/
+  printf "\n# boot u-boot kernel\nkernel=u-boot.bin\n" >> $R/boot/firmware/config.txt
+
+  # Set U-Boot command file
+  cat <<EOM >$R/boot/firmware/uboot.mkimage
+# Tell Linux that it is booting on a Raspberry Pi2
+setenv machid 0x00000c42
+
+# Set the kernel boot command line
+setenv bootargs "earlyprintk ${CMDLINE}"
+
+# Save these changes to u-boot's environment
+saveenv
+
+# Load the existing Linux kernel into RAM
+fatload mmc 0:1 \${kernel_addr_r} kernel7.img
+
+# Boot the kernel we have just loaded
+bootz \${kernel_addr_r}
+EOM
+
+  # Generate U-Boot image from command file
+  chroot_exec mkimage -A arm -O linux -T script -C none -a 0x00000000 -e 0x00000000 -n "RPi2 Boot Script" -d /boot/firmware/uboot.mkimage /boot/firmware/boot.scr
+fi
diff --git a/bootstrap.d/42-fbturbo.sh b/bootstrap.d/42-fbturbo.sh
new file mode 100644
index 0000000..4d99016
--- /dev/null
+++ b/bootstrap.d/42-fbturbo.sh
@@ -0,0 +1,34 @@
+#
+# Fetch and build fbturbo Xorg driver
+#
+
+. ./functions.sh
+
+if [ "$ENABLE_FBTURBO" = true ] ; then
+  # Fetch fbturbo driver sources
+  git -C $R/tmp clone https://github.com/ssvb/xf86-video-fbturbo.git
+
+  # Install Xorg build dependencies
+  chroot_exec apt-get install -q -y --no-install-recommends xorg-dev xutils-dev x11proto-dri2-dev libltdl-dev libtool automake libdrm-dev
+
+  # Build and install fbturbo driver inside chroot
+  chroot_exec /bin/bash -c "cd /tmp/xf86-video-fbturbo; autoreconf -vi; ./configure --prefix=/usr; make; make install"
+
+  # Add fbturbo driver to Xorg configuration
+  cat <<EOM >$R/usr/share/X11/xorg.conf.d/99-fbturbo.conf
+Section "Device"
+        Identifier "Allwinner A10/A13 FBDEV"
+        Driver "fbturbo"
+        Option "fbdev" "/dev/fb0"
+        Option "SwapbuffersWait" "true"
+EndSection
+EOM
+
+  # Remove Xorg build dependencies
+  chroot_exec apt-get -q -y purge --auto-remove xorg-dev xutils-dev x11proto-dri2-dev libltdl-dev libtool automake libdrm-dev
+fi
+
+# Remove gcc/c++ build environment from the chroot
+if [ "$ENABLE_UBOOT" = true ] || [ "$ENABLE_FBTURBO" = true ]; then
+  chroot_exec apt-get -y -q purge --auto-remove bc binutils cpp cpp-4.9 g++ g++-4.9 gcc gcc-4.9 libasan1 libatomic1 libc-dev-bin libc6-dev libcloog-isl4 libgcc-4.9-dev libgomp1 libisl10 libmpc3 libmpfr4 libstdc++-4.9-dev libubsan0 linux-compiler-gcc-4.9-arm linux-libc-dev make
+fi
diff --git a/bootstrap.d/50-firstboot.sh b/bootstrap.d/50-firstboot.sh
new file mode 100644
index 0000000..b9f1d76
--- /dev/null
+++ b/bootstrap.d/50-firstboot.sh
@@ -0,0 +1,24 @@
+#
+# First boot actions
+#
+
+. ./functions.sh
+
+cat files/firstboot/10-begin.sh > $R/etc/rc.firstboot
+
+# Ensure openssh server host keys are regenerated on first boot
+if [ "$ENABLE_SSHD" = true ] ; then
+  cat files/firstboot/21-generate-ssh-keys.sh >> $R/etc/rc.firstboot
+  rm -f $R/etc/ssh/ssh_host_*
+fi
+
+if [ "$EXPANDROOT" = true ] ; then
+  cat files/firstboot/22-expandroot.sh >> $R/etc/rc.firstboot
+fi
+
+cat files/firstboot/99-finish.sh >> $R/etc/rc.firstboot
+chmod +x $R/etc/rc.firstboot
+
+sed -i '/exit 0/d' $R/etc/rc.local
+echo /etc/rc.firstboot >> $R/etc/rc.local
+echo exit 0 >> $R/etc/rc.local
diff --git a/functions.sh b/functions.sh
new file mode 100644
index 0000000..5071129
--- /dev/null
+++ b/functions.sh
@@ -0,0 +1,23 @@
+cleanup (){
+  # Clean up all temporary mount points
+  set +x
+  set +e
+  echo "killing processes using mount point ..."
+  fuser -k $R
+  sleep 3
+  fuser -9 -k -v $R
+  echo "removing temporary mount points ..."
+  umount -l $R/proc 2> /dev/null
+  umount -l $R/sys 2> /dev/null
+  umount -l $R/dev/pts 2> /dev/null
+  umount "$BUILDDIR/mount/boot/firmware" 2> /dev/null
+  umount "$BUILDDIR/mount" 2> /dev/null
+  losetup -d "$ROOT_LOOP" 2> /dev/null
+  losetup -d "$FRMW_LOOP" 2> /dev/null
+  trap - 0 1 2 3 6
+}
+
+chroot_exec() {
+  # Exec command in chroot
+  LANG=C LC_ALL=C DEBIAN_FRONTEND=noninteractive chroot $R $*
+}
diff --git a/rpi2-gen-image.sh b/rpi2-gen-image.sh
index 880afbf..61f9b81 100755
--- a/rpi2-gen-image.sh
+++ b/rpi2-gen-image.sh
@@ -15,25 +15,7 @@
 # Copyright (C) 2015 Luca Falavigna <dktrkranz@debian.org>
 ########################################################################
 
-# Clean up all temporary mount points
-cleanup (){
-  set +x
-  set +e
-  echo "removing temporary mount points ..."
-  umount -l $R/proc 2> /dev/null
-  umount -l $R/sys 2> /dev/null
-  umount -l $R/dev/pts 2> /dev/null
-  umount "$BUILDDIR/mount/boot/firmware" 2> /dev/null
-  umount "$BUILDDIR/mount" 2> /dev/null
-  losetup -d "$ROOT_LOOP" 2> /dev/null
-  losetup -d "$FRMW_LOOP" 2> /dev/null
-  trap - 0 1 2 3 6
-}
-
-# Exec command in chroot
-chroot_exec() {
-  LANG=C LC_ALL=C chroot $R $*
-}
+source ./functions.sh
 
 set -e
 set -x
@@ -43,7 +25,7 @@ RELEASE=${RELEASE:=jessie}
 KERNEL=${KERNEL:=3.18.0-trunk-rpi2}
 
 # Build settings
-BASEDIR=./images/${RELEASE}
+BASEDIR=$(pwd)/images/${RELEASE}
 BUILDDIR=${BASEDIR}/build
 
 # General settings
@@ -96,6 +78,10 @@ ENABLE_HARDNET=${ENABLE_HARDNET:=false}
 ENABLE_IPTABLES=${ENABLE_IPTABLES:=false}
 ENABLE_SPLITFS=${ENABLE_SPLITFS:=false}
 
+# Kernel compilation settings
+BUILD_KERNEL=${BUILD_KERNEL:=false}
+KERNEL_HEADERS=${KERNEL_HEADERS:=true}
+
 # Image chroot path
 R=${BUILDDIR}/chroot
 CHROOT_SCRIPTS=${CHROOT_SCRIPTS:=""}
@@ -118,6 +104,11 @@ if [ "$(id -u)" -ne "0" ] ; then
   exit 1
 fi
 
+# Add packages required for kernel cross compilation
+if [ "$BUILD_KERNEL" = true ] ; then
+  REQUIRED_PACKAGES="${REQUIRED_PACKAGES} crossbuild-essential-armhf"
+fi
+
 # Check if all required packages are installed
 for package in $REQUIRED_PACKAGES ; do
   if [ "`dpkg-query -W -f='${Status}' $package`" != "install ok installed" ] ; then
@@ -214,416 +205,18 @@ if [ "$ENABLE_XORG" = true ] ; then
   APT_INCLUDES="${APT_INCLUDES},xorg"
 fi
 
-# Base debootstrap (unpack only)
-if [ "$ENABLE_MINBASE" = true ] ; then
-  http_proxy=${APT_PROXY} debootstrap --arch=armhf --variant=minbase --foreign --include=${APT_INCLUDES} $RELEASE $R http://${APT_SERVER}/debian
-else
-  http_proxy=${APT_PROXY} debootstrap --arch=armhf --foreign --include=${APT_INCLUDES} $RELEASE $R http://${APT_SERVER}/debian
-fi
-
-# Copy qemu emulator binary to chroot
-cp /usr/bin/qemu-arm-static $R/usr/bin
-
-# Copy debian-archive-keyring.pgp
-chroot $R mkdir -p /usr/share/keyrings
-cp /usr/share/keyrings/debian-archive-keyring.gpg $R/usr/share/keyrings/debian-archive-keyring.gpg
-
-# Complete the bootstrapping process
-chroot $R /debootstrap/debootstrap --second-stage
-
-# Mount required filesystems
-mount -t proc none $R/proc
-mount -t sysfs none $R/sys
-mount --bind /dev/pts $R/dev/pts
-
-# Use proxy inside chroot
-if [ -z "$APT_PROXY" ] ; then
-  echo "Acquire::http::Proxy \"$APT_PROXY\";" >> $R/etc/apt/apt.conf.d/10proxy
-fi
-
-# Pin package flash-kernel to repositories.collabora.co.uk
-cat <<EOM >$R/etc/apt/preferences.d/flash-kernel
-Package: flash-kernel
-Pin: origin repositories.collabora.co.uk
-Pin-Priority: 1000
-EOM
-
-# Set up timezone
-echo ${TIMEZONE} >$R/etc/timezone
-chroot_exec dpkg-reconfigure -f noninteractive tzdata
-
-# Upgrade collabora package index and install collabora keyring
-echo "deb https://repositories.collabora.co.uk/debian ${RELEASE} rpi2" >$R/etc/apt/sources.list
-chroot_exec apt-get -qq -y update
-chroot_exec apt-get -qq -y --force-yes install collabora-obs-archive-keyring
-
-# Set up initial sources.list
-cat <<EOM >$R/etc/apt/sources.list
-deb http://${APT_SERVER}/debian ${RELEASE} main contrib
-#deb-src http://${APT_SERVER}/debian ${RELEASE} main contrib
-
-deb http://${APT_SERVER}/debian/ ${RELEASE}-updates main contrib
-#deb-src http://${APT_SERVER}/debian/ ${RELEASE}-updates main contrib
-
-deb http://security.debian.org/ ${RELEASE}/updates main contrib
-#deb-src http://security.debian.org/ ${RELEASE}/updates main contrib
-
-deb https://repositories.collabora.co.uk/debian ${RELEASE} rpi2
-EOM
-
-# Upgrade package index and update all installed packages and changed dependencies
-chroot_exec apt-get -qq -y update
-chroot_exec apt-get -qq -y -u dist-upgrade
-
-# Set up default locale and keyboard configuration
-if [ "$ENABLE_MINBASE" = false ] ; then
-  # Set locale choice in debconf db, even though dpkg-reconfigure ignores and overwrites them due to some bug
-  # https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=684134 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=685957
-  # ... so we have to set locales manually
-  if [ "$DEFLOCAL" = "en_US.UTF-8" ] ; then
-    chroot_exec echo "locales locales/locales_to_be_generated multiselect ${DEFLOCAL} UTF-8" | debconf-set-selections
-  else
-    # en_US.UTF-8 should be available anyway : https://www.debian.org/doc/manuals/debian-reference/ch08.en.html#_the_reconfiguration_of_the_locale
-    chroot_exec echo "locales locales/locales_to_be_generated multiselect en_US.UTF-8 UTF-8, ${DEFLOCAL} UTF-8" | debconf-set-selections
-    chroot_exec sed -i "/en_US.UTF-8/s/^#//" /etc/locale.gen
-  fi
-  chroot_exec sed -i "/${DEFLOCAL}/s/^#//" /etc/locale.gen
-  chroot_exec echo "locales locales/default_environment_locale select ${DEFLOCAL}" | debconf-set-selections
-  chroot_exec locale-gen
-  chroot_exec update-locale LANG=${DEFLOCAL}
-
-  # Keyboard configuration, if requested
-  if [ "$XKBMODEL" != "" ] ; then
-    chroot_exec sed -i "s/^XKBMODEL.*/XKBMODEL=\"${XKBMODEL}\"/" /etc/default/keyboard
-  fi
-  if [ "$XKBLAYOUT" != "" ] ; then
-    chroot_exec sed -i "s/^XKBLAYOUT.*/XKBLAYOUT=\"${XKBLAYOUT}\"/" /etc/default/keyboard
-  fi
-  if [ "$XKBVARIANT" != "" ] ; then
-    chroot_exec sed -i "s/^XKBVARIANT.*/XKBVARIANT=\"${XKBVARIANT}\"/" /etc/default/keyboard
-  fi
-  if [ "$XKBOPTIONS" != "" ] ; then
-    chroot_exec sed -i "s/^XKBOPTIONS.*/XKBOPTIONS=\"${XKBOPTIONS}\"/" /etc/default/keyboard
-  fi
-  chroot_exec dpkg-reconfigure -f noninteractive keyboard-configuration
-  # Set up font console
-  case "${DEFLOCAL}" in
-    *UTF-8)
-      chroot_exec sed -i 's/^CHARMAP.*/CHARMAP="UTF-8"/' /etc/default/console-setup
-      ;;
-    *)
-      chroot_exec sed -i 's/^CHARMAP.*/CHARMAP="guess"/' /etc/default/console-setup
-      ;;
-  esac
-  chroot_exec dpkg-reconfigure -f noninteractive console-setup
-fi
-
-# Kernel installation
-# Install flash-kernel last so it doesn't try (and fail) to detect the platform in the chroot
-chroot_exec apt-get -qq -y --no-install-recommends install linux-image-${KERNEL} raspberrypi-bootloader-nokernel
-chroot_exec apt-get -qq -y install flash-kernel
-
-VMLINUZ="$(ls -1 $R/boot/vmlinuz-* | sort | tail -n 1)"
-[ -z "$VMLINUZ" ] && exit 1
-cp $VMLINUZ $R/boot/firmware/kernel7.img
-
-# Set up IPv4 hosts
-echo ${HOSTNAME} >$R/etc/hostname
-cat <<EOM >$R/etc/hosts
-127.0.0.1       localhost
-127.0.1.1       ${HOSTNAME}
-EOM
-if [ "$NET_ADDRESS" != "" ] ; then
-NET_IP=$(echo ${NET_ADDRESS} | cut -f 1 -d'/')
-sed -i "s/^127.0.1.1/${NET_IP}/" $R/etc/hosts
-fi
-
-# Set up IPv6 hosts
-if [ "$ENABLE_IPV6" = true ] ; then
-cat <<EOM >>$R/etc/hosts
-
-::1             localhost ip6-localhost ip6-loopback
-ff02::1         ip6-allnodes
-ff02::2         ip6-allrouters
-EOM
-fi
-
-# Place hint about network configuration
-cat <<EOM >$R/etc/network/interfaces
-# Debian switched to systemd-networkd configuration files.
-# please configure your networks in '/etc/systemd/network/'
-EOM
-
-if [ "$ENABLE_DHCP" = true ] ; then
-# Enable systemd-networkd DHCP configuration for interface eth0
-cat <<EOM >$R/etc/systemd/network/eth.network
-[Match]
-Name=eth0
-
-[Network]
-DHCP=yes
-EOM
-
-# Set DHCP configuration to IPv4 only
-if [ "$ENABLE_IPV6" = false ] ; then
-  sed -i "s/^DHCP=yes/DHCP=v4/" $R/etc/systemd/network/eth.network
-fi
-else # ENABLE_DHCP=false
-cat <<EOM >$R/etc/systemd/network/eth.network
-[Match]
-Name=eth0
-
-[Network]
-DHCP=no
-Address=${NET_ADDRESS}
-Gateway=${NET_GATEWAY}
-DNS=${NET_DNS_1}
-DNS=${NET_DNS_2}
-Domains=${NET_DNS_DOMAINS}
-NTP=${NET_NTP_1}
-NTP=${NET_NTP_2}
-EOM
-fi
-
-# Enable systemd-networkd service
-chroot_exec systemctl enable systemd-networkd
-
-# Generate crypt(3) password string
-ENCRYPTED_PASSWORD=`mkpasswd -m sha-512 ${PASSWORD}`
-
-# Set up default user
-if [ "$ENABLE_USER" = true ] ; then
-  chroot_exec adduser --gecos pi --add_extra_groups --disabled-password pi
-  chroot_exec usermod -a -G sudo -p "${ENCRYPTED_PASSWORD}" pi
-fi
-
-# Set up root password or not
-if [ "$ENABLE_ROOT" = true ]; then
-  chroot_exec usermod -p "${ENCRYPTED_PASSWORD}" root
-
-  if [ "$ENABLE_ROOT_SSH" = true ]; then
-    sed -i 's|[#]*PermitRootLogin.*|PermitRootLogin yes|g' $R/etc/ssh/sshd_config
-  fi
-else
-  chroot_exec usermod -p \'!\' root
-fi
-
-# Set up firmware boot cmdline
-if [ "$ENABLE_SPLITFS" = true ] ; then
-  CMDLINE="dwc_otg.lpm_enable=0 root=/dev/sda1 rootfstype=ext4 rootflags=commit=100,data=writeback elevator=deadline rootwait net.ifnames=1 console=tty1"
-else
-  CMDLINE="dwc_otg.lpm_enable=0 root=/dev/mmcblk0p2 rootfstype=ext4 rootflags=commit=100,data=writeback elevator=deadline rootwait net.ifnames=1 console=tty1"
-fi
-
-# Set up serial console support (if requested)
-if [ "$ENABLE_CONSOLE" = true ] ; then
-  CMDLINE="${CMDLINE} console=ttyAMA0,115200 kgdboc=ttyAMA0,115200"
-fi
-
-# Set up IPv6 networking support
-if [ "$ENABLE_IPV6" = false ] ; then
-  CMDLINE="${CMDLINE} ipv6.disable=1"
-fi
-
-echo "${CMDLINE}" >$R/boot/firmware/cmdline.txt
-
-# Set up firmware config
-install -o root -g root -m 644 files/config.txt $R/boot/firmware/config.txt
-
-# Load snd_bcm2835 kernel module at boot time
-if [ "$ENABLE_SOUND" = true ] ; then
-  echo "snd_bcm2835" >>$R/etc/modules
-fi
-
-# Set smallest possible GPU memory allocation size: 16MB (no X)
-if [ "$ENABLE_MINGPU" = true ] ; then
-  echo "gpu_mem=16" >>$R/boot/firmware/config.txt
-fi
-
-# Create symlinks
-ln -sf firmware/config.txt $R/boot/config.txt
-ln -sf firmware/cmdline.txt $R/boot/cmdline.txt
-
-# Prepare modules-load.d directory
-mkdir -p $R/lib/modules-load.d/
-
-# Load random module on boot
-if [ "$ENABLE_HWRANDOM" = true ] ; then
-  cat <<EOM >$R/lib/modules-load.d/rpi2.conf
-bcm2708_rng
-EOM
-fi
-
-# Prepare modprobe.d directory
-mkdir -p $R/etc/modprobe.d/
-
-# Blacklist sound modules
-install -o root -g root -m 644 files/modprobe.d/raspi-blacklist.conf $R/etc/modprobe.d/raspi-blacklist.conf
-
-# Create default fstab
-install -o root -g root -m 644 files/fstab $R/etc/fstab
-if [ "$ENABLE_SPLITFS" = true ] ; then
-  sed -i '/mmcblk0p2/sda1/' $R/etc/fstab
-fi
-
-# Avoid swapping and increase cache sizes
-install -o root -g root -m 644 files/sysctl.d/81-rpi-vm.conf $R/etc/sysctl.d/81-rpi-vm.conf
-
-# Enable network stack hardening
-if [ "$ENABLE_HARDNET" = true ] ; then
-  install -o root -g root -m 644 files/sysctl.d/81-rpi-net-hardening.conf $R/etc/sysctl.d/81-rpi-net-hardening.conf
-
-# Enable resolver warnings about spoofed addresses
-  cat <<EOM >>$R/etc/host.conf
-spoof warn
-EOM
-fi
-
-# First boot actions
-cat files/firstboot/10-begin.sh > $R/etc/rc.firstboot
-
-# Ensure openssh server host keys are regenerated on first boot
-if [ "$ENABLE_SSHD" = true ] ; then
-  cat files/firstboot/21-generate-ssh-keys.sh >> $R/etc/rc.firstboot
-  rm -f $R/etc/ssh/ssh_host_*
-fi
-
-if [ "$EXPANDROOT" = true ] ; then
-  cat files/firstboot/22-expandroot.sh >> $R/etc/rc.firstboot
-fi
-
-cat files/firstboot/99-finish.sh >> $R/etc/rc.firstboot
-chmod +x $R/etc/rc.firstboot
-
-sed -i '/exit 0/d' $R/etc/rc.local
-echo /etc/rc.firstboot >> $R/etc/rc.local
-echo exit 0 >> $R/etc/rc.local
-
-# Disable rsyslog
-if [ "$ENABLE_RSYSLOG" = false ]; then
-  sed -i 's|[#]*ForwardToSyslog=yes|ForwardToSyslog=no|g' $R/etc/systemd/journald.conf
-  chroot_exec systemctl disable rsyslog
-  chroot_exec apt-get purge -q -y --force-yes rsyslog
-fi
-
-# Enable serial console systemd style
-if [ "$ENABLE_CONSOLE" = true ] ; then
-  chroot_exec systemctl enable serial-getty\@ttyAMA0.service
-fi
-
-# Enable firewall based on iptables started by systemd service
-if [ "$ENABLE_IPTABLES" = true ] ; then
-  # Create iptables configuration directory
-  mkdir -p "$R/etc/iptables"
-
-  # Create iptables systemd service
-  install -o root -g root -m 644 files/iptables/iptables.service $R/etc/systemd/system/iptables.service
-
-  # Create flush-table script called by iptables service
-  install -o root -g root -m 755 files/iptables/flush-iptables.sh $R/etc/iptables/flush-iptables.sh
-
-  # Create iptables rule file
-  install -o root -g root -m 644 files/iptables/iptables.rules $R/etc/iptables/iptables.rules
-
-  # Reload systemd configuration and enable iptables service
-  chroot_exec systemctl daemon-reload
-  chroot_exec systemctl enable iptables.service
-
-  if [ "$ENABLE_IPV6" = true ] ; then
-    # Create ip6tables systemd service
-    install -o root -g root -m 644 files/iptables/ip6tables.service $R/etc/systemd/system/ip6tables.service
-
-    # Create ip6tables file
-    install -o root -g root -m 755 files/iptables/flush-ip6tables.sh $R/etc/iptables/flush-ip6tables.sh
-
-    install -o root -g root -m 644 files/iptables/ip6tables.rules $R/etc/iptables/ip6tables.rules
-
-    # Reload systemd configuration and enable iptables service
-    chroot_exec systemctl daemon-reload
-    chroot_exec systemctl enable ip6tables.service
-  fi
-fi
-
-# Remove SSHD related iptables rules
-if [ "$ENABLE_SSHD" = false ] ; then
- sed -e '/^#/! {/SSH/ s/^/# /}' -i $R/etc/iptables/iptables.rules 2> /dev/null
- sed -e '/^#/! {/SSH/ s/^/# /}' -i $R/etc/iptables/ip6tables.rules 2> /dev/null
-fi
-
-# Install gcc/c++ build environment inside the chroot
-if [ "$ENABLE_UBOOT" = true ] || [ "$ENABLE_FBTURBO" = true ]; then
-  chroot_exec apt-get install -q -y --force-yes --no-install-recommends linux-compiler-gcc-4.9-arm g++ make bc
-fi
-
-# Fetch and build U-Boot bootloader
-if [ "$ENABLE_UBOOT" = true ] ; then
-  # Fetch U-Boot bootloader sources
-  git -C $R/tmp clone git://git.denx.de/u-boot.git
-
-  # Build and install U-Boot inside chroot
-  chroot_exec make -C /tmp/u-boot/ rpi_2_defconfig all
-
-  # Copy compiled bootloader binary and set config.txt to load it
-  cp $R/tmp/u-boot/u-boot.bin $R/boot/firmware/
-  printf "\n# boot u-boot kernel\nkernel=u-boot.bin\n" >> $R/boot/firmware/config.txt
-
-  # Set U-Boot command file
-  cat <<EOM >$R/boot/firmware/uboot.mkimage
-# Tell Linux that it is booting on a Raspberry Pi2
-setenv machid 0x00000c42
-
-# Set the kernel boot command line
-setenv bootargs "earlyprintk ${CMDLINE}"
-
-# Save these changes to u-boot's environment
-saveenv
-
-# Load the existing Linux kernel into RAM
-fatload mmc 0:1 \${kernel_addr_r} kernel7.img
-
-# Boot the kernel we have just loaded
-bootz \${kernel_addr_r}
-EOM
-
-  # Generate U-Boot image from command file
-  chroot_exec mkimage -A arm -O linux -T script -C none -a 0x00000000 -e 0x00000000 -n "RPi2 Boot Script" -d /boot/firmware/uboot.mkimage /boot/firmware/boot.scr
-fi
-
-# Fetch and build fbturbo Xorg driver
-if [ "$ENABLE_FBTURBO" = true ] ; then
-  # Fetch fbturbo driver sources
-  git -C $R/tmp clone https://github.com/ssvb/xf86-video-fbturbo.git
-
-  # Install Xorg build dependencies
-  chroot_exec apt-get install -q -y --no-install-recommends xorg-dev xutils-dev x11proto-dri2-dev libltdl-dev libtool automake libdrm-dev
-
-  # Build and install fbturbo driver inside chroot
-  chroot_exec /bin/bash -c "cd /tmp/xf86-video-fbturbo; autoreconf -vi; ./configure --prefix=/usr; make; make install"
-
-  # Add fbturbo driver to Xorg configuration
-  cat <<EOM >$R/usr/share/X11/xorg.conf.d/99-fbturbo.conf
-Section "Device"
-        Identifier "Allwinner A10/A13 FBDEV"
-        Driver "fbturbo"
-        Option "fbdev" "/dev/fb0"
-        Option "SwapbuffersWait" "true"
-EndSection
-EOM
-
-  # Remove Xorg build dependencies
-  chroot_exec apt-get -q -y purge --auto-remove xorg-dev xutils-dev x11proto-dri2-dev libltdl-dev libtool automake libdrm-dev
-fi
+## Main bootstrap
+for i in bootstrap.d/*.sh; do
+  . $i
+done
 
-# Remove gcc/c++ build environment from the chroot
-if [ "$ENABLE_UBOOT" = true ] || [ "$ENABLE_FBTURBO" = true ]; then
-  chroot_exec apt-get -y -q purge --auto-remove bc binutils cpp cpp-4.9 g++ g++-4.9 gcc gcc-4.9 libasan1 libatomic1 libc-dev-bin libc6-dev libcloog-isl4 libgcc-4.9-dev libgomp1 libisl10 libmpc3 libmpfr4 libstdc++-4.9-dev libubsan0 linux-compiler-gcc-4.9-arm linux-libc-dev make
+## Custom bootstrap scripts
+if [ -d "custom.d" ]; then
+  for i in custom.d/*.sh; do
+    . $i
+  done
 fi
 
-# Clean cached downloads
-chroot_exec apt-get -y clean
-chroot_exec apt-get -y autoclean
-chroot_exec apt-get -y autoremove
-
 # Invoke custom scripts
 if [ -n "${CHROOT_SCRIPTS}" ]; then
   cp -r "${CHROOT_SCRIPTS}" "${R}/chroot_scripts"
@@ -631,6 +224,11 @@ if [ -n "${CHROOT_SCRIPTS}" ]; then
   rm -rf "${R}/chroot_scripts"
 fi
 
+## Cleanup
+chroot_exec apt-get -y clean
+chroot_exec apt-get -y autoclean
+chroot_exec apt-get -y autoremove
+
 # Unmount mounted filesystems
 umount -l $R/proc
 umount -l $R/sys
@@ -647,6 +245,7 @@ rm -f $R/var/lib/urandom/random-seed
 [ -L $R/var/lib/dbus/machine-id ] || rm -f $R/var/lib/dbus/machine-id
 rm -f $R/etc/machine-id
 rm -fr $R/etc/apt/apt.conf.d/10proxy
+rm -f $R/etc/resolv.conf
 
 # Calculate size of the chroot directory in KB
 CHROOT_SIZE=$(expr `du -s $R | awk '{ print $1 }'`)
@@ -690,7 +289,7 @@ unit: sectors
 3 : start=                  0, size=                 0, Id= 0
 4 : start=                  0, size=                 0, Id= 0
 EOM
-  # Set up temporary loop devices and build filesystems
+  # Set up temporary loop devices
   FRMW_LOOP="$(losetup -o 1M --sizelimit 64M -f --show $BASEDIR/${DATE}-debian-${RELEASE}-frmw.img)"
   ROOT_LOOP="$(losetup -o 1M -f --show $BASEDIR/${DATE}-debian-${RELEASE}-root.img)"
 else
@@ -705,11 +304,12 @@ unit: sectors
 3 : start=                  0, size=                 0, Id= 0
 4 : start=                  0, size=                 0, Id= 0
 EOM
-  # Set up temporary loop devices and build filesystems
+  # Set up temporary loop devices
   FRMW_LOOP="$(losetup -o 1M --sizelimit 64M -f --show $BASEDIR/${DATE}-debian-${RELEASE}.img)"
   ROOT_LOOP="$(losetup -o 65M -f --show $BASEDIR/${DATE}-debian-${RELEASE}.img)"
 fi
 
+# Build filesystems
 mkfs.vfat "$FRMW_LOOP"
 mkfs.ext4 "$ROOT_LOOP"
 
@@ -732,12 +332,12 @@ if [ "$ENABLE_SPLITFS" = true ] ; then
   bmaptool create -o "$BASEDIR/${DATE}-debian-${RELEASE}-root.bmap" "$BASEDIR/${DATE}-debian-${RELEASE}-root.img"
 
   # Image was successfully created
-  echo "$BASEDIR/${DATE}-debian-${RELEASE}-frmw.img ($(expr ${TABLE_SECTORS} + ${FRMW_SECTORS} \* 512 \/ 1024)M)" ": successfully created"
-  echo "$BASEDIR/${DATE}-debian-${RELEASE}-root.img ($(expr ${TABLE_SECTORS} + ${ROOT_SECTORS} \* 512 \/ 1024)M)" ": successfully created"
+  echo "$BASEDIR/${DATE}-debian-${RELEASE}-frmw.img ($(expr ${TABLE_SECTORS} + ${FRMW_SECTORS} \* 512 \/ 1024 \/ 1024)M)" ": successfully created"
+  echo "$BASEDIR/${DATE}-debian-${RELEASE}-root.img ($(expr ${TABLE_SECTORS} + ${ROOT_SECTORS} \* 512 \/ 1024 \/ 1024)M)" ": successfully created"
 else
   # (optional) create block map file for "bmaptool"
   bmaptool create -o "$BASEDIR/${DATE}-debian-${RELEASE}.bmap" "$BASEDIR/${DATE}-debian-${RELEASE}.img"
 
   # Image was successfully created
-  echo "$BASEDIR/${DATE}-debian-${RELEASE}.img ($(expr ${TABLE_SECTORS} + ${FRMW_SECTORS} + ${ROOT_SECTORS} \* 512 \/ 1024)M)" ": successfully created"
+  echo "$BASEDIR/${DATE}-debian-${RELEASE}.img ($(expr ${TABLE_SECTORS} + ${FRMW_SECTORS} + ${ROOT_SECTORS} \* 512 \/ 1024 \/ 1024)M)" ": successfully created"
 fi