Hi Jakub, can you remember what is:

• Drop unused 1bpp support

I don’t remember it. We added 2 years ago +-

Did you test the branch with the brick?

Here, you have an example to test that everything goes well:
https://github.com/ev3dev-lang-java/template-project-gradle/blob/master/src/main/java/example/programming/FractalCircle.java

Did you test the branch with the brick?

No, I don't currently have a free SD card (currently it is used by a non-robotic RPi, although I can reflash it later).

I think I remember that Jessie used 1bpp packed black and white bitmaps and Stretch used 32bpp XRGB8888 bitmaps. However, because the Jessie codepath somehow didn't work, the old LCD implementation was copied over untouched and the new code is used only on Stretch (and Buster nowadays).

Hi Jakub, did you test it?

Not yet, and as such I have to close this PR.

When you test in local, I will merge it.
The idea is good