Uh, with Yocto at least, it's also pretty simple for a basic bootable disk image/packages... downloading all the source and compiling the cross toolchain along

Uh, with Yocto at least, it's also pretty simple for a basic bootable disk image/packages... downloading all the source and compiling the cross toolchain along the way... git clone git://git.yoctoproject.org/poky cd poky git checkout -b hardknott -t origin/hardknott source oe-init-build-env MACHINE=qemuarm64 bitbake core-image-sato But after the first build you may want more - bringing in other functional layers for different features (maybe you want docker?), support for different boards (same OS distro for x86_64 and ARM, or your own custom board... plus it can build a whole SDK for you for local development/debugging?), customization of target files, pulling from updated upstreams, support in deployment and throughout the device lifecycle, custom package feeds, etc. There's a lot going for Yocto, it has a deep learning curve but does a pretty good job of taming the complexity of managing an entire OS distro.