4A studio

Looks like I accidentally erased most of my u-boot from SPI flash since I don't have much experience with it. Are there any ways to restore it and what soft- and hardware do I need, apart from having a Linux PC and UART?

I have the same issue than @1111Windows had back in March. That's because I chose the wrong option in armbian-config. How do I revert to original (or, at least, working) u-boot? UART connection through putty is working.

@sven-ola thanks for your job, much appreciated. However, are there any chances for the GPU driver to be ported to forky-based Armbian to get both GPU acceleration support and fresher software (except for older patched mesa, of course)? For example, there is lxqt-wayland-session but starting from 2.1.0 version of lxqt while Ubuntu-based Armbian and Bianbu provide 1.4.0 version only. I happened to test it with kwin_wayland as the compositor with one of your previous images and it kind of works but it can suddenly freeze the whole system. I also tested your last image with Gnome but I started it from tty (the command is "XDG_SESSION_TYPE=wayland gnome-shell") and I got a bit higher score of 440-ish in glmark2-es2-wayland.