Hello, I was using balbes150’s Armbian Mate running from SD card. Also in balbes150, Display manager also works to rotate screen.
I flashed the Khadas Ubuntu Mate and discovered, as you have, that this does not work. And as known, also not in Display manager.
On Khadas, monitor shows as Unknown in Display manager.
In balbes150, Display manager identifies monitor correctly as, ViewSonic Corporation 22"
My apologies, I regret I don’t have a solution for your issue.
Which version of Armbian Mate did you use? I tried Armbian_5.32_S9xxx_Ubuntu_xenial_3.14.29_mate_20170830.img but I can’t rotate the display. And monitor shows as Unknown in Display manager like our ubuntu images.
OK. I’ve tried Armbian_5.32_S9xxx_Ubuntu_xenial_4.13.0-next-20170905_mate.img, and I can rotate display screen directly from setting rotation. But Armbian_5.32_S9xxx_Ubuntu_xenial_3.14.29_mate_20170830 and Armbian_5.32_S9xxx_Ubuntu_xenial_3.14.29_mate_20170907.img still can’t rotate the screen, and monitor shows as Unknown in Display manager like our ubuntu images. So @balbes150 could you please patiently tell us what’s the difference between Armbian 3.14 and 4.13 ubuntu mate? Thanks a lot!
In these images different kernel. The kernel 4.13 is not required to use fbset utility to manage the screen. Therefore, the output operates immediately from the start of the kernel and displays the standard elements with the number of cores. As far as I know, at the core of 4.13 significant change in the drivers of the video output. For this reason better to check with Neil Armstrong.