For screen and mouse/analog rotate (book mode), see here for a workaround:

https://retropie.org.uk/forum/topic/29456/solved-nds-lr-desmume2015-rotate-also-mouse-axis-when-video-is-rotated

It relies on lr-desmume2015. It is a workaround as the book mode issue is neither implemented yet in the lr-desmume2015 nor in retroarch.

@Gokilz would you mind adding the rotate/book mode aspect to the subject on your initial post? This would make it easier to find this topic in future when searching for a similar issue as yours.

Hi,

ok. But then I must install all drivers by hand, lot of work.
I have updated retropie, so it should be the newest version.

@mitu wow thank you so much! I didn’t realize it was such a simple solution lol