Most of the functionality is present but many important bits are still being developed.
A standard called SystemReady exists. For the systems that actually follow its standards, you can have a single ARM OS installation image that you copy to a USB drive and can then boot through UEFI and run with no problems on an Ampere server, an NXP device, an Nvidia Jetson system, and more.
Unfortunately it’s a pretty new standard, only since 2020, and Qualcomm in particular is a major holdout who hasn’t been using it.
Just like x86, you still need the OS to have drivers for the particular device you’re installing on, but this standard at least lets you have a unified image, and many ARM vendors have been getting better about upstreaming open-source drivers in the Linux kernel.
