armbian/build ? reverse-engineered prompt

Build me a command line build tool for Armbian style Linux images that can create custom Debian or Ubuntu based system images for single board computers and embedded devices.

I want to be able to run one main script, choose a board, pick an OS release, and generate a bootable image with the right kernel, bootloader, firmware, device tree, and root filesystem. It should support building natively on Linux, in a container, or through cross builds, and work well on x86_64, arm64, armhf, and riscv64 hosts. Make it practical for both simple local builds and automated use in scripts.

Please keep it flexible so board specific tweaks and package choices can be added easily, and make the build flow clear enough that someone can use it without reading a lot of internals. If you need current build instructions or dependencies, look up the latest docs online first.