Buildroot builds a cross-compiler, a Linux kernel and a complete root filesystem from source, driven by one Kconfig-style configuration file. Starting from the qemu_arm_vexpress_defconfig that ships with Buildroot 2026.05.1, two commands produce a bootable ARM system you can run under QEMU. The images you ship are the ones in output/images/; output/target/ looks like a root filesystem but must never be copied to a device.
This post starts a new hands-on series on Buildroot for embedded Linux. By the end of this part you will have built a working Buildroot root filesystem for an ARM target, booted it under QEMU, and understood which generated directories are safe to ship. Later parts add your own packages, a BR2_EXTERNAL tree, kernel and bootloader integration, and reproducible image output. If the choice between build systems is still open, our earlier Yocto vs Buildroot comparison covers it; this series assumes the decision is made.
What you need
A Linux host, several gigabytes of free disk space, and a network connection. No development board is needed for this part; QEMU stands in for the hardware. On a Debian or Ubuntu host, this covers the mandatory packages the manual lists, plus the ncurses development files that menuconfig needs:
