Roadrunner technical documentation Buy

Compiling Linux Kernel 5.4 LTS

This article illustrates how to generate a bootable Linux Kernel image for RoadRunner SOM

It is advisable to have a Debug Port Interface or similar during the kernel bootstrap

If you are using a Linux PC with Ubuntu or Debian follow this article:

If you are using a Raspberry Pi board consider that the programs (gcc, g++, ...), required to compile the Linux Kernel, are already installed by default on Raspbian OS so probably you have to install just to add few programs more:

sudo apt update
sudo apt install bc bison libssl-dev flex

It is possible to use the Raspberry Pi native gcc compiler so remove this parameter:


from the command provided below

Step-by-step Kernel cross-compilation procedure:

Procedure tested on a Linux Ubuntu , Debian and on a Raspberry Pi 4 Raspbian Buster Lite.

Kernel sources download

Open a terminal on your Linux PC and download the Linux Kernel sources from the main stream repository:


Extract the Kernel sources from the compressed file by typing:

tar xvfJ linux-5.4.163.tar.xz

Move inside the new folder just created:

cd linux-5.4.163

Compile the Kernel image

Download the Kernel configuration file for Roadrunner by typing:

wget -O arch/arm/configs/acme-roadrunner_defconfig

Then select from the following list the right Linux configuration for your board by typing one of these commands:

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- acme-roadrunner_defconfig

Compile the Linux Kernel sources and generate the binary compressed image file to save in the first partition of microSD card.

make -j4 ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- zImage
Image arch/arm/boot/zImage is ready

Generate the Device Tree Blob file (.dtb)

Download our example of device tree source by typing:

wget -O arch/arm/boot/dts/acme-roadrunner.dts

Now compile the device tree file requested by your board by selecting one of the following commands:

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- acme-roadrunner.dtb

Compile the Kernel modules

The image generated contains the Linux Kernel and all the built-in device drivers (option [*] in menuconfig) compiled with it.

Al the drivers compiled as external modules (option [M] in menuconfig) need to be compiled and saved in the rootfs /lib directory on the second partition of the microSD. We didn't use any [M] flag in our defconfig so this procedure is not requested but. in case you add something. these are the commands to use to compile them:

make modules -j4 ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf-
make modules_install INSTALL_MOD_PATH=./modules ARCH=arm

Copy the boot files into the first microSD partition

Insert a formatted microSD with the boot loader (at91bootstrap) and the rootfs contents already created in your Linux PC and copy on it these files:

Write the Linux Kernel image (zImage) and the device tree blob (acme-roadrunner.dtb) inside the first microSD partition:

sudo cp arch/arm/boot/dts/acme-roadrunner.dtb /media/$USER/boot
sudo cp arch/arm/boot/zImage /media/$USER/boot

Write the Linux Kernel modules inside the second microSD partition:

sudo rsync -avc modules/lib/. /media/$USER/rootfs/lib/.

After the first boot

At the first access to the board command line update the module dependencies by typing this command:

depmod -a



Customize the default Linux Kernel configuration:

If you need to customize the Kernel configuration or you just want to take a look around the Kernel setup type:

make ARCH=arm menuconfig

and navigate inside the Kernel configuration using the arrow keys and following the help provided by the menuconfig interface.

Create a defconfig of your own Kernel configuration

make ARCH=arm savedefconfig

The file defconfig contains your configuration. You could rename and copy it in arch/arm/configs/

cp defconfig arch/arm/configs/my_defconfig

Home page Roadrunner technical documentation Buy