Custom CuBox Image

Table of Contents

The following document describes our own method of creating a custom Kali Linux CuBox ARM image and is targeted at developers. If you would like to install a pre-made Kali image, check out our Install Kali on CuBox article.

You’ll need to have root privileges to do this procedure, or the ability to escalate your privileges with the command “sudo su”.

01. Create a Kali rootfs

Build a Kali rootfs as described in our Kali documentation, using an armhf architecture. By the end of this process, you should have a populated rootfs directory in ~/arm-stuff/rootfs/kali-armhf.

02. Create the Image File

Next, we create the physical image file, which will hold our CuBox rootfs and boot images:

kali@kali:~$ sudo apt install -y kpartx xz-utils sharutils
kali@kali:~$ mkdir -p ~/arm-stuff/images/
kali@kali:~$ cd ~/arm-stuff/images/
kali@kali:~$ dd if=/dev/zero of=kali-custom-cubox.img conv=fsync bs=4M count=7000

03. Partition and Mount the Image File

kali@kali:~$ parted kali-custom-cubox.img --script -- mklabel msdos
kali@kali:~$ parted kali-custom-cubox.img --script -- mkpart primary ext4 0 -1
kali@kali:~$ loopdevice=$(losetup -f --show kali-custom-cubox.img)
kali@kali:~$ device=`kpartx -va $loopdevice| sed -E 's/.*(loop[0-9])p.*/\1/g' | head -1`
kali@kali:~$ device="/dev/mapper/${device}"
kali@kali:~$ rootp=${device}p1
kali@kali:~$ mkfs.ext4 $rootp
kali@kali:~$ mkdir -p root
kali@kali:~$ mount $rootp root

04. Copy and Modify the Kali rootfs

kali@kali:~$ rsync -HPavz /root/arm-stuff/rootfs/kali-armhf/ root
kali@kali:~$ echo nameserver > root/etc/resolv.conf

05. Compile the CuBox Kernel and Modules

If you’re not using ARM hardware as the development environment, you will need to set up an ARM cross-compilation environment to build an ARM kernel and modules. Once that’s done, proceed with the following instructions:

kali@kali:~$ mkdir -p ~/arm-stuff/kernel/
kali@kali:~$ cd ~/arm-stuff/kernel/
kali@kali:~$ git clone --depth 1
kali@kali:~$ cd linux/
kali@kali:~$ touch .scmversion
kali@kali:~$ mkdir -p ../patches/
kali@kali:~$ wget -O ../patches/mac80211.patch
kali@kali:~$ patch -p1 --no-backup-if-mismatch < ../patches/mac80211.patch
kali@kali:~$ export ARCH=arm
kali@kali:~$ export CROSS_COMPILE=~/arm-stuff/kernel/toolchains/arm-eabi-linaro-4.6.2/bin/arm-eabi-
kali@kali:~$ make cubox_defconfig

# configure your kernel !
kali@kali:~$ make menuconfig
kali@kali:~$ make -j$( cat /proc/cpuinfo|grep processor | wc -l )
kali@kali:~$ make modules_install INSTALL_MOD_PATH=~/arm-stuff/images/root
kali@kali:~$ make uImage
kali@kali:~$ cp arch/arm/boot/uImage ~/arm-stuff/images/root/boot
kali@kali:~$ cat <<EOF > ~/arm-stuff/images/root/boot/boot.txt
echo "== Executing ${directory}${bootscript} on ${device_name} partition ${partition} =="
setenv unit_no 0
setenv root_device ?

if itest.s ${device_name} -eq usb; then
itest.s $root_device -eq ? && ext4ls usb 0:1 /dev && setenv root_device /dev/sda1 && setenv unit_no 0
itest.s $root_device -eq ? && ext4ls usb 1:1 /dev && setenv root_device /dev/sda1 && setenv unit_no 1

if itest.s ${device_name} -eq mmc; then
itest.s $root_device -eq ? && ext4ls mmc 0:2 /dev && setenv root_device /dev/mmcblk0p2
itest.s $root_device -eq ? && ext4ls mmc 0:1 /dev && setenv root_device /dev/mmcblk0p1

if itest.s ${device_name} -eq ide; then
itest.s $root_device -eq ? && ext4ls ide 0:1 /dev && setenv root_device /dev/sda1

if itest.s $root_device -ne ?; then
setenv bootargs "console=ttyS0,115200n8 vmalloc=448M video=dovefb:lcd0:1920x1080-32@60-edid clcd.lcd0_enable=1 clcd.lcd1_enable=0 root=${root_device} rootfstype=ext4"
setenv loadimage "${fstype}load ${device_name} ${unit_no}:${partition} 0x00200000 ${directory}${image_name}"
$loadimage && bootm 0x00200000
echo "!! Unable to load ${directory}${image_name} from ${device_name} ${unit_no}:${partition} !!"

echo "!! Unable to locate root partition on ${device_name} !!"
kali@kali:~$ mkimage -A arm -T script -C none -n "Boot.scr for CuBox" -d ~/arm-stuff/images/root/boot/boot.txt ~/arm-stuff/images/root/boot/boot.scr
kali@kali:~$ umount $rootp
kali@kali:~$ kpartx -dv $loopdevice
kali@kali:~$ losetup -d $loopdevice

While ‘/dev/sdX’ is used in the command, the ‘/dev/sdX’ should be replaced with the proper device label. ‘/dev/sdX’ will not overwrite any devices, and can safely be used in documentation to prevent accidental overwrites. Please use the correct device label.

Use the dd command to image this file to your SD card. In our example, we assume the storage device is located at /dev/sdX. Change this as needed:

kali@kali:~$ dd if=kali-linux-cubox.img of=/dev/sdX conv=fsync bs=4M

Once the dd operation is complete, unmount and eject the SD card and boot your CuBox into Kali Linux

Updated on: 2023-Nov-17
Author: steev