chromebook-nyan.sh

#!/usr/bin/env bash
#
# Kali Linux ARM build-script for Chromebook (Nyan Acer Tegra) (32-bit)
# Source: https://gitlab.com/kalilinux/build-scripts/kali-arm
#
# This is a community script - you will need to generate your own image to use
# More information: https://www.kali.org/docs/arm/chromebook-nyan/
#

# Stop on error
set -e

# Uncomment to activate debug
# debug=true

if [ "$debug" = true ]; then
    exec > >(tee -a -i "${0%.*}.log") 2>&1
    set -x

fi

# Architecture
architecture=${architecture:-"armhf"}

# Generate a random machine name to be used
machine=$(
    tr -cd 'A-Za-z0-9' </dev/urandom | head -c16
    echo
)

# Custom hostname variable
hostname=${2:-kali}

# Custom image file name variable - MUST NOT include .img at the end
image_name=${3:-kali-linux-$1-chromebook-nyan}

# Suite to use, valid options are:
# kali-rolling, kali-dev, kali-bleeding-edge, kali-dev-only, kali-experimental, kali-last-snapshot
suite=${suite:-"kali-rolling"}

# Free space rootfs in MiB
free_space="300"

# /boot partition in MiB
bootsize="128"

# Select compression, xz or none
compress="xz"

# Choose filesystem format to format (ext3 or ext4)
fstype="ext3"

# If you have your own preferred mirrors, set them here
mirror=${mirror:-"http://http.kali.org/kali"}

# GitLab URL Kali repository
kaligit="https://gitlab.com/kalilinux"

# GitHub raw URL
githubraw="https://raw.githubusercontent.com"

# Check EUID=0 you can run any binary as root
if [[ $EUID -ne 0 ]]; then
    echo "This script must be run as root or have super user permissions" >&2
    echo "Use: sudo $0 ${1:-2.0} ${2:-kali}" >&2

    exit 1

fi

# Pass version number
if [[ $# -eq 0 ]]; then
    echo "Please pass version number, e.g. $0 2.0, and (if you want) a hostname, default is kali" >&2
    exit 0

fi

# Check exist bsp directory
if [ ! -e "bsp" ]; then
    echo "Error: missing bsp directory structure" >&2
    echo "Please clone the full repository ${kaligit}/build-scripts/kali-arm" >&2

    exit 255

fi

# Current directory
repo_dir="$(pwd)"

# Base directory
base_dir=${repo_dir}/nyan-"$1"

# Working directory
work_dir="${base_dir}/kali-${architecture}"

# Check directory build
if [ -e "${base_dir}" ]; then
    echo "${base_dir} directory exists, will not continue" >&2

    exit 1

elif [[ ${repo_dir} =~ [[:space:]] ]]; then
    echo "The directory "\"${repo_dir}"\" contains whitespace. Not supported." >&2

    exit 1

else
    echo "The base_dir thinks it is: ${base_dir}"
    mkdir -p ${base_dir}

fi

components="main,contrib,non-free"

arm="kali-linux-arm ntpdate"

base="apt-transport-https apt-utils bash-completion console-setup dialog \
e2fsprogs ifupdown initramfs-tools inxi iw man-db mlocate net-tools \
netcat-traditional parted pciutils psmisc rfkill screen tmux unrar usbutils \
vim wget whiptail zerofree"

desktop="kali-desktop-xfce kali-root-login xfonts-terminus xinput \
xserver-xorg-input-libinput xserver-xorg-input-synaptics \
xserver-xorg-video-fbdev"

tools="kali-linux-default"

services="apache2 atftpd"

extras="alsa-utils bc bison bluez bluez-firmware kali-linux-core \
libnss-systemd libssl-dev triggerhappy"

packages="${arm} ${base} ${services}"

kernel_release="R71-11151.B-chromeos-3.10"

# Automatic configuration to use an http proxy, such as apt-cacher-ng
# You can turn off automatic settings by uncommenting apt_cacher=off
# apt_cacher=off
# By default the proxy settings are local, but you can define an external proxy
# proxy_url="http://external.intranet.local"
apt_cacher=${apt_cacher:-"$(lsof -i :3142 | cut -d ' ' -f3 | uniq | sed '/^\s*$/d')"}
if [ -n "$proxy_url" ]; then
    export http_proxy=$proxy_url

elif [ "$apt_cacher" = "apt-cacher-ng" ]; then
    if [ -z "$proxy_url" ]; then
        proxy_url=${proxy_url:-"http://127.0.0.1:3142/"}
        export http_proxy=$proxy_url

    fi
fi

# Detect architecture
if [[ "${architecture}" == "arm64" ]]; then
    qemu_bin="/usr/bin/qemu-aarch64-static"
    lib_arch="aarch64-linux-gnu"

elif [[ "${architecture}" == "armhf" ]]; then
    qemu_bin="/usr/bin/qemu-arm-static"
    lib_arch="arm-linux-gnueabihf"

elif [[ "${architecture}" == "armel" ]]; then
    qemu_bin="/usr/bin/qemu-arm-static"
    lib_arch="arm-linux-gnueabi"

fi

# create the rootfs - not much to modify here, except maybe throw in some more packages if you want
eatmydata debootstrap --foreign \
    --keyring=/usr/share/keyrings/kali-archive-keyring.gpg \
    --include=kali-archive-keyring,eatmydata \
    --components=${components} \
    --arch ${architecture} ${suite} ${work_dir} http://http.kali.org/kali

# systemd-nspawn environment
systemd-nspawn_exec() {
    LANG=C systemd-nspawn -q --bind-ro ${qemu_bin} -M ${machine} -D ${work_dir} "$@"
}

# We need to manually extract eatmydata to use it for the second stage
for archive in ${work_dir}/var/cache/apt/archives/*eatmydata*.deb; do
    dpkg-deb --fsys-tarfile "$archive" >${work_dir}/eatmydata
    tar -xkf ${work_dir}/eatmydata -C ${work_dir}
    rm -f ${work_dir}/eatmydata

done

# Prepare dpkg to use eatmydata
systemd-nspawn_exec dpkg-divert --divert /usr/bin/dpkg-eatmydata --rename --add /usr/bin/dpkg

cat >${work_dir}/usr/bin/dpkg <<EOF
#!/bin/sh
if [ -e /usr/lib/${lib_arch}/libeatmydata.so ]; then
    [ -n "\${LD_PRELOAD}" ] && LD_PRELOAD="\$LD_PRELOAD:"
    LD_PRELOAD="\$LD_PRELOAD\$so"

fi

for so in /usr/lib/${lib_arch}/libeatmydata.so; do
    [ -n "\$LD_PRELOAD" ] && LD_PRELOAD="\$LD_PRELOAD:"
    LD_PRELOAD="\$LD_PRELOAD\$so"

done

export LD_PRELOAD
exec "\$0-eatmydata" --force-unsafe-io "\$@"
EOF

chmod 0755 ${work_dir}/usr/bin/dpkg

# debootstrap second stage
systemd-nspawn_exec eatmydata /debootstrap/debootstrap --second-stage

cat <<EOF >${work_dir}/etc/apt/sources.list
deb ${mirror} ${suite} ${components//,/ }
#deb-src ${mirror} ${suite} ${components//,/ }
EOF

# Set hostname
echo "${hostname}" >${work_dir}/etc/hostname

# So X doesn't complain, we add kali to hosts
cat <<EOF >${work_dir}/etc/hosts
127.0.0.1       ${hostname} localhost
::1             localhost ip6-localhost ip6-loopback
fe00::0         ip6-localnet
ff00::0         ip6-mcastprefix
ff02::1         ip6-allnodes
ff02::2         ip6-allrouters
EOF

# Disable IPv6
cat <<EOF >${work_dir}/etc/modprobe.d/ipv6.conf
# Don't load ipv6 by default
alias net-pf-10 off
EOF

cat <<EOF >${work_dir}/etc/network/interfaces
auto lo
iface lo inet loopback
EOF

# DNS server
echo "nameserver ${nameserver}" >"${work_dir}"/etc/resolv.conf

# Copy directory bsp into build dir
cp -rp bsp ${work_dir}

# Workaround for LP: #520465
export MALLOC_CHECK_=0

# Enable the use of http proxy in third-stage in case it is enabled
if [ -n "$proxy_url" ]; then
    echo "Acquire::http { Proxy \"$proxy_url\" };" >${work_dir}/etc/apt/apt.conf.d/66proxy

fi

# Third stage
cat <<EOF >${work_dir}/third-stage
#!/bin/bash -e
export DEBIAN_FRONTEND=noninteractive

eatmydata apt-get update

eatmydata apt-get -y install binutils ca-certificates console-common cryptsetup-bin git initramfs-tools less locales nano u-boot-tools

# Create kali user with kali password... but first, we need to manually make some groups because they don't yet exist..
# This mirrors what we have on a pre-installed VM, until the script works properly to allow end users to set up their own... user
# However we leave off floppy, because who a) still uses them, and b) attaches them to an SBC!?
# And since a lot of these have serial devices of some sort, dialout is added as well
# scanner, lpadmin and bluetooth have to be added manually because they don't
# yet exist in /etc/group at this point
groupadd -r -g 118 bluetooth
groupadd -r -g 113 lpadmin
groupadd -r -g 122 scanner
groupadd -g 1000 kali

useradd -m -u 1000 -g 1000 -G sudo,audio,bluetooth,cdrom,dialout,dip,lpadmin,netdev,plugdev,scanner,video,kali -s /bin/bash kali
echo "kali:kali" | chpasswd

aptops="--allow-change-held-packages -o dpkg::options::=--force-confnew -o Acquire::Retries=3"

# This looks weird, but we do it twice because every so often, there's a failure to download from the mirror
# So to workaround it, we attempt to install them twice
eatmydata apt-get install -y \$aptops ${packages} || eatmydata apt-get --yes --fix-broken install
eatmydata apt-get install -y \$aptops ${packages} || eatmydata apt-get --yes --fix-broken install
eatmydata apt-get install -y \$aptops ${desktop} ${extras} ${tools} || eatmydata apt-get --yes --fix-broken install
eatmydata apt-get install -y \$aptops ${desktop} ${extras} ${tools} || eatmydata apt-get --yes --fix-broken install
eatmydata apt-get install -y \$aptops --autoremove systemd-timesyncd || eatmydata apt-get --yes --fix-broken install
eatmydata apt-get dist-upgrade -y \$aptops

eatmydata apt-get -y --allow-change-held-packages --purge autoremove

# Linux console/Keyboard configuration
echo 'console-common console-data/keymap/policy select Select keymap from full list' | debconf-set-selections
echo 'console-common console-data/keymap/full select en-latin1-nodeadkeys' | debconf-set-selections

# Copy all services
cp -p /bsp/services/all/*.service /etc/systemd/system/

# Regenerated the shared-mime-info database on the first boot
# since it fails to do so properly in a chroot
systemctl enable smi-hack

# Enable sshd
systemctl enable ssh

# Allow users to use NM over ssh
install -m644 /bsp/polkit/10-NetworkManager.pkla /var/lib/polkit-1/localauthority/50-local.d

cd /root
apt download -o APT::Sandbox::User=root ca-certificates 2>/dev/null

# Copy over the default bashrc
cp /etc/skel/.bashrc /root/.bashrc

# Set a REGDOMAIN.  This needs to be done or wireless doesn't work correctly on the RPi 3B+
sed -i -e 's/REGDOM.*/REGDOMAIN=00/g' /etc/default/crda

# Enable login over serial
echo "T0:23:respawn:/sbin/agetty -L ttyAMA0 115200 vt100" >> /etc/inittab

# Try and make the console a bit nicer
# Set the terminus font for a bit nicer display
sed -i -e 's/FONTFACE=.*/FONTFACE="Terminus"/' /etc/default/console-setup
sed -i -e 's/FONTSIZE=.*/FONTSIZE="6x12"/' /etc/default/console-setup

# Fix startup time from 5 minutes to 15 secs on raise interface wlan0
sed -i 's/^TimeoutStartSec=5min/TimeoutStartSec=15/g' "/usr/lib/systemd/system/networking.service"

rm -f /usr/bin/dpkg
EOF

# Run third stage
chmod 0755 ${work_dir}/third-stage
systemd-nspawn_exec /third-stage

# Clean up eatmydata
systemd-nspawn_exec dpkg-divert --remove --rename /usr/bin/dpkg

# Clean system
systemd-nspawn_exec <<'EOF'
rm -f /0
rm -rf /bsp
fc-cache -frs
rm -rf /tmp/*
rm -rf /etc/*-
rm -rf /hs_err*
rm -rf /userland
rm -rf /opt/vc/src
rm -f /etc/ssh/ssh_host_*
rm -rf /var/lib/dpkg/*-old
rm -rf /var/lib/apt/lists/*
rm -rf /var/cache/apt/*.bin
rm -rf /var/cache/apt/archives/*
rm -rf /var/cache/debconf/*.data-old
for logs in $(find /var/log -type f); do > $logs; done
history -c
EOF

# Disable the use of http proxy in case it is enabled
if [ -n "$proxy_url" ]; then
    unset http_proxy
    rm -rf ${work_dir}/etc/apt/apt.conf.d/66proxy

fi

# Mirror & suite replacement
if [[ ! -z "${4}" || ! -z "${5}" ]]; then
    mirror=${4}
    suite=${5}

fi

# Define sources.list
cat <<EOF >${work_dir}/etc/apt/sources.list
deb ${mirror} ${suite} ${components//,/ }
#deb-src ${mirror} ${suite} ${components//,/ }
EOF

# Pull in the gcc 5.3 cross compiler to build the kernel
# Debian uses a newer compiler and the chromebook kernel doesn't support
# that
cd "${base_dir}"
git clone --depth 1 https://gitlab.com/kalilinux/packages/gcc-arm-linux-gnueabihf-4-7.git gcc-arm-linux-gnueabihf-4.7

# Kernel section.  If you want to use a custom kernel, or configuration, replace
# them in this section
cd "${base_dir}"
git clone --depth 1 https://chromium.googlesource.com/chromiumos/third_party/kernel -b release-${kernel_release} ${work_dir}/usr/src/kernel
cd ${work_dir}/usr/src/kernel
mkdir -p ${work_dir}/usr/src/kernel/firmware/nvidia/tegra124/
cp ${work_dir}/lib/firmware/nvidia/tegra124/xusb.bin firmware/nvidia/tegra124/
cp ${repo_dir}/kernel-configs/chromebook-3.10.config .config
cp ${repo_dir}/kernel-configs/chromebook-3.10.config ${work_dir}/usr/src/nyan.config
git rev-parse HEAD >${work_dir}/usr/src/kernel-at-commit
export ARCH=arm

# Edit the CROSS_COMPILE variable as needed
export CROSS_COMPILE="${base_dir}"/gcc-arm-linux-gnueabihf-4.7/bin/arm-linux-gnueabihf-
patch -p1 --no-backup-if-mismatch <${repo_dir}/patches/mac80211-3.8.patch
patch -p1 --no-backup-if-mismatch <${work_dir}/patches/0001-mwifiex-do-not-create-AP-and-P2P-interfaces-upon-dri-3.8.patch
patch -p1 --no-backup-if-mismatch <${work_dir}/patches/0001-Comment-out-a-pr_debug-print.patch
make WIFIVERSION="-3.8" oldconfig || die "Kernel config options added"
make WIFIVERSION="-3.8" -j $(grep -c processor /proc/cpuinfo)
make WIFIVERSION="-3.8" dtbs
make WIFIVERSION="-3.8" modules_install INSTALL_MOD_PATH=${work_dir}

cat <<__EOF__ >${work_dir}/usr/src/kernel/arch/arm/boot/kernel-nyan.its
/dts-v1/;

/ {
    description = "ChromeOS kernel image with one or more FDT blobs";
    #address-cells = <1>;
    images {
        kernel@1{
            description = "kernel";
            data = /incbin/("zImage");
            type = "kernel_noload";
            arch = "arm";
            os = "linux";
            compression = "none";
            load = <0>;
            entry = <0>;
        };

        fdt@1{
            description = "tegra124-nyan-big-rev0_2.dtb";
            data = /incbin/("dts/tegra124-nyan-big-rev0_2.dtb");
            type = "flat_dt";
            arch = "arm";
            compression = "none";
            hash@1{
                algo = "sha1";
            };
        };

        fdt@2{
            description = "tegra124-nyan-big-rev3_7.dtb";
            data = /incbin/("dts/tegra124-nyan-big-rev3_7.dtb");
            type = "flat_dt";
            arch = "arm";
            compression = "none";
            hash@1{
                algo = "sha1";
            };
        };

        fdt@3{
            description = "tegra124-nyan-big-rev8_9.dtb";
            data = /incbin/("dts/tegra124-nyan-big-rev8_9.dtb");
            type = "flat_dt";
            arch = "arm";
            compression = "none";
            hash@1{
                algo = "sha1";
            };
        };

        fdt@4{
            description = "tegra124-nyan-blaze.dtb";
            data = /incbin/("dts/tegra124-nyan-blaze.dtb");
            type = "flat_dt";
            arch = "arm";
            compression = "none";
            hash@1{
                algo = "sha1";
            };
        };

        fdt@5{
            description = "tegra124-nyan-rev0.dtb";
            data = /incbin/("dts/tegra124-nyan-rev0.dtb");
            type = "flat_dt";
            arch = "arm";
            compression = "none";
            hash@1{
                algo = "sha1";
            };
        };

        fdt@6{
            description = "tegra124-nyan-rev1.dtb";
            data = /incbin/("dts/tegra124-nyan-rev1.dtb");
            type = "flat_dt";
            arch = "arm";
            compression = "none";
            hash@1{
                algo = "sha1";
            };
        };

        fdt@7{
            description = "tegra124-nyan-kitty-rev0_3.dtb";
            data = /incbin/("dts/tegra124-nyan-kitty-rev0_3.dtb");
            type = "flat_dt";
            arch = "arm";
            compression = "none";
            hash@1{
                algo = "sha1";
            };
        };

        fdt@8{
            description = "tegra124-nyan-kitty-rev8.dtb";
            data = /incbin/("dts/tegra124-nyan-kitty-rev8.dtb");
            type = "flat_dt";
            arch = "arm";
            compression = "none";
            hash@1{
                algo = "sha1";
            };
        };
    };

    configurations {
        default = "conf@1";

        conf@1{
            kernel = "kernel@1";
            fdt = "fdt@1";
        };

        conf@2{
            kernel = "kernel@1";
            fdt = "fdt@2";
        };

        conf@3{
            kernel = "kernel@1";
            fdt = "fdt@3";
        };

        conf@4{
            kernel = "kernel@1";
            fdt = "fdt@4";
        };

        conf@5{
            kernel = "kernel@1";
            fdt = "fdt@5";
        };

        conf@6{
            kernel = "kernel@1";
            fdt = "fdt@6";
        };

        conf@7{
            kernel = "kernel@1";
            fdt = "fdt@7";
        };

        conf@8{
            kernel = "kernel@1";
            fdt = "fdt@8";
        };
    };
};
__EOF__

cd ${work_dir}/usr/src/kernel/arch/arm/boot
mkimage -f kernel-nyan.its nyan-big-kernel

# BEHOLD THE POWER OF PARTUUID/PARTNROFF
echo "noinitrd console=tty1 quiet root=PARTUUID=%U/PARTNROFF=1 rootwait rw lsm.module_locking=0 net.ifnames=0 rootfstype=$fstype" >cmdline

# Pulled from ChromeOS, this is exactly what they do because there's no
# bootloader in the kernel partition on ARM
dd if=/dev/zero of=bootloader.bin bs=512 count=1

vbutil_kernel --arch arm --pack "${base_dir}"/kernel.bin --keyblock /usr/share/vboot/devkeys/kernel.keyblock --signprivate /usr/share/vboot/devkeys/kernel_data_key.vbprivk --version 1 --config cmdline --bootloader bootloader.bin --vmlinuz nyan-big-kernel

cd ${work_dir}/usr/src/kernel

# Clean up our build of the kernel, then copy the config and run make
# modules_prepare so that users can more easily build kernel modules..
make WIFIVERSION="-3.8" mrproper
cp ../nyan.config .config
cd "${base_dir}"

# Fix up the symlink for building external modules
# kernver is used so we don't need to keep track of what the current compiled
# version is
kernver=$(ls ${work_dir}/lib/modules/)
cd ${work_dir}/lib/modules/${kernver}
rm build
rm source
ln -s /usr/src/kernel build
ln -s /usr/src/kernel source
cd "${base_dir}"

# Lid switch
cat <<EOF >${work_dir}/etc/udev/rules.d/99-tegra-lid-switch.rules
ACTION=="remove", GOTO="tegra_lid_switch_end"
SUBSYSTEM=="input", KERNEL=="event*", SUBSYSTEMS=="platform", KERNELS=="gpio-keys.4", TAG+="power-switch"
LABEL="tegra_lid_switch_end"
EOF

# Bit of a hack, this is so the eMMC doesn't show up on the desktop
cat <<EOF >${work_dir}/etc/udev/rules.d/99-hide-emmc-partitions.rules
KERNEL=="mmcblk0*", ENV{UDISKS_IGNORE}="1"
EOF

# Disable uap0 and p2p0 interfaces in NetworkManager
mkdir -p ${work_dir}/etc/NetworkManager/
printf '\n[keyfile]\nunmanaged-devices=interface-name:p2p0\n' >>${work_dir}/etc/NetworkManager/NetworkManager.conf

#nvidia device nodes
cat <<EOF >${work_dir}/lib/udev/rules.d/51-nvrm.rules
KERNEL=="knvmap", GROUP="video", MODE="0660"
KERNEL=="nvhdcp1", GROUP="video", MODE="0660"
KERNEL=="nvhost-as-gpu", GROUP="video", MODE="0660"
KERNEL=="nvhost-ctrl", GROUP="video", MODE="0660"
KERNEL=="nvhost-ctrl-gpu", GROUP="video", MODE="0660"
KERNEL=="nvhost-dbg-gpu", GROUP="video", MODE="0660"
KERNEL=="nvhost-gpu", GROUP="video", MODE="0660"
KERNEL=="nvhost-msenc", GROUP="video", MODE="0660"
KERNEL=="nvhost-prof-gpu", GROUP="video", MODE="0660"
KERNEL=="nvhost-tsec", GROUP="video", MODE="0660"
KERNEL=="nvhost-vic", GROUP="video", MODE="0660"
KERNEL=="nvmap", GROUP="video", MODE="0660"
KERNEL=="tegra_dc_0", GROUP="video", MODE="0660"
KERNEL=="tegra_dc_1", GROUP="video", MODE="0660"
KERNEL=="tegra_dc_ctrl", GROUP="video", MODE="0660"
EOF

# Touchpad configuration
mkdir -p ${work_dir}/etc/X11/xorg.conf.d
cp ${repo_dir}/bsp/xorg/10-synaptics-chromebook.conf ${work_dir}/etc/X11/xorg.conf.d/

# lp0 resume firmware..
# Check https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/master/sys-kernel/tegra_lp0_resume/
# to find the lastest commit to use (note: CROS_WORKON_COMMIT )
cd "${base_dir}"
git clone https://chromium.googlesource.com/chromiumos/third_party/coreboot
cd "${base_dir}"/coreboot
git checkout fb840ee4195f9c365375e8914e243ce2f5e4f7bf
make -C src/soc/nvidia/tegra124/lp0 GCC_PREFIX=arm-linux-gnueabihf-
mkdir -p ${work_dir}/lib/firmware/tegra12x/
cp src/soc/nvidia/tegra124/lp0/tegra_lp0_resume.fw ${work_dir}/lib/firmware/tegra12x/
cd "${base_dir}"

# Calculate the space to create the image
root_size=$(du -s -B1 ${work_dir} --exclude=${work_dir}/boot | cut -f1)
root_extra=$((${root_size} / 1024 / 1000 * 5 * 1024 / 5))
raw_size=$(($((${free_space} * 1024)) + ${root_extra} + $((${bootsize} * 1024)) + 4096))

# Create the disk and partition it
echo "Creating image file ${image_name}.img"
fallocate -l $(echo ${raw_size}Ki | numfmt --from=iec-i --to=si) "${image_dir}/${image_name}.img"
parted -s "${image_dir}/${image_name}.img" mklabel gpt
cgpt create -z "${image_dir}/${image_name}.img"
cgpt create "${image_dir}/${image_name}.img"

cgpt add -i 1 -t kernel -b 8192 -s 32768 -l kernel -S 1 -T 5 -P 10 "${image_dir}/${image_name}.img"
cgpt add -i 2 -t data -b 40960 -s $(expr $(cgpt show "${image_dir}/${image_name}.img" | grep 'Sec GPT table' | awk '{ print \$1 }') - 40960) -l Root "${image_dir}/${image_name}.img"

loopdevice=$(losetup -f --show ${repo_dir}/${image_name}.img)
device=$(kpartx -va ${loopdevice} | sed 's/.*\(loop[0-9]\+\)p.*/\1/g' | head -1)
sleep 5
device="/dev/mapper/${device}"
bootp=${device}p1
rootp=${device}p2

if [[ $fstype == ext4 ]]; then
    features="-O ^64bit,^metadata_csum"

elif [[ $fstype == ext3 ]]; then
    features="-O ^64bit"

fi

mkfs $features -t $fstype -L ROOTFS ${rootp}

mkdir -p "${base_dir}"/root
mount ${rootp} "${base_dir}"/root

# We do this down here to get rid of the build system's resolv.conf after running through the build
echo "nameserver ${nameserver}" >"${work_dir}"/etc/resolv.conf

# Create an fstab so that we don't mount / read-only
UUID=$(blkid -s UUID -o value ${rootp})
echo "UUID=$UUID /               $fstype    errors=remount-ro 0       1" >>${work_dir}/etc/fstab

echo "Rsyncing rootfs into image file"
rsync -HPavz -q ${work_dir}/ ${base_dir}/root/

# Unmount partitions
sync
umount ${rootp}

dd if="${base_dir}"/kernel.bin of=${bootp}

cgpt repair ${loopdevice}

kpartx -dv ${loopdevice}
losetup -d ${loopdevice}

# Limit CPU function
limit_cpu() {
    # Random name group
    rand=$(
        tr -cd 'A-Za-z0-9' </dev/urandom | head -c4
        echo
    )

    cgcreate -g cpu:/cpulimit-${rand}                # Name of group cpulimit
    cgset -r cpu.shares=800 cpulimit-${rand}         # Max 1024
    cgset -r cpu.cfs_quota_us=80000 cpulimit-${rand} # Max 100000

    # Retry command
    local n=1
    local max=5
    local delay=2

    while true; do
        cgexec -g cpu:cpulimit-${rand} "$@" && break || {
            if [[ $n -lt $max ]]; then
                ((n++))
                echo -e "\e[31m Command failed. Attempt $n/$max \033[0m"

                sleep $delay

            else
                echo "The command has failed after $n attempts."

                break

            fi
        }

    done
}

if [ $compress = xz ]; then
    if [ $(arch) == 'x86_64' ]; then
        echo "Compressing ${image_name}.img"

        # cpu_cores = Number of cores to use
        [ $(nproc) -lt 3 ] || cpu_cores=3

        # -p Nº cpu cores use
        limit_cpu pixz -p ${cpu_cores:-2} "${image_dir}/${image_name}.img"
        chmod 0644 ${repo_dir}/${image_name}.img.xz

    fi

else
    chmod 0644 "${image_dir}/${image_name}.img"

fi

# Clean up all the temporary build stuff and remove the directories
# Comment this out to keep things around if you want to see what may have gone wrong
echo "Removing temporary build files"
rm -rf "${base_dir}"