Tell us how you used Buildroot in your projects…

Buildroot is a tool for creating embedded systems that generates a cross-compiler toolchain, filesystem, Linux kernel, and bootloader for the target platform.

In its projects, Buildroot was used for:

Creating custom Linux distributions for embedded devices based on ARM and MIPS. This allowed including only necessary packages and drivers, minimizing image size and resource consumption.
Rapid prototyping of hardware platforms. With Buildroot, it was easy to generate a basic system with a minimal set of utilities for testing new chips and peripherals.
Automating image builds within CI/CD pipelines. Integration with Jenkins and GitLab CI enabled automating the process of creating and testing firmware.
Managing dependencies of software for the target platform. Buildroot provides a unified way to build and install packages.

An example configuration file .config for a basic system:

// Target options
BR2_aarch64=y
BR2_cortex_a53=y

// Toolchain options
BR2_TOOLCHAIN_BUILDROOT=y

// System configuration
BR2_TARGET_GENERIC_HOSTNAME="my-device"
BR2_TARGET_GENERIC_ROOT_PASSWD=""
BR2_SYSTEM_DHCP="eth0"
BR2_INIT_BUSYBOX=y

// Kernel options
BR2_LINUX_KERNEL=y
BR2_LINUX_KERNEL_VERSION="5.15.y"
BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="board/myboard/linux.config"

// Filesystem options
BR2_TARGET_ROOTFS_EXT2=y

The build process typically involved the following steps:

Configuration selection: make defconfig or make menuconfig.
Building the image: make.

The build output is a filesystem image, kernel, and bootloader (if applicable).

Example build commands:

// Clean build directory
make clean
// Configure with default settings
make myboard_defconfig
// Start the build process
make

To add a custom package, .mk files were used in the corresponding packages directory.

Example .mk file for the mypackage package:

// mypackage.mk

MYPACKAGE_VERSION = 1.0
MYPACKAGE_SITE = $(call github,myuser,mypackage,$(MYPACKAGE_VERSION))
MYPACKAGE_LICENSE = MIT
MYPACKAGE_LICENSE_FILES = LICENSE

// Define how to build and install the package
define MYPACKAGE_BUILD_CMDS
	$(TARGET_CONFIGURE_OPTS) $(MAKE) -C $(@D)
endef

define MYPACKAGE_INSTALL_TARGET_CMDS
	$(MAKE) -C $(@D) INSTALL_DIR=$(TARGET_DIR)/usr/bin install
endef

// Include the package definition boilerplate
$(eval $(generic-package))

Buildroot has proven effective in creating lightweight and reliable embedded systems.

Tell us how you used Buildroot in your projects.