The video_rotation works like a champ (so my games play in the correct orientation), but the retroarch menu doesn't seem to be able to rotate. I've got a cocktail style machine and have the screen rotated 90 deg. I've tried values 1, 2, 3, and 4 with no changes to the retroarch menu.
that's right. this function is intended to rotate the GAME, not the whole session. it is working as intended. it looks like there's an outstanding issue to rotate the whole lot outside of X, that you could follow here: https://github.com/libretro/RetroArch/issues/6770
unfortunately the ability to rotate the entire session outside of X does not exist for pi4, as far as i know.natinusala created this issue in libretro/RetroArch open Menu ignores video_rotation configuration #6770