It uses an Amlogic S922X aka the G12B. Support is generally pretty good, there's a dedicated community that has been very active pushing upstream[1].

Except the ARM G51 Bifrost gpu, which has only recently started to see viability[2] thanks to one hacker's reverse engineering. If you want to read a lot of words, there's a status report from the libreeelec Kodi-based media player distribution distribution that's a year old, that lays out a lot of what needs be done, from a very video-intense perspective[3]; this is before recent reverse engineering efforts, & largely discusses uses closed proprietary blobs, but still interesting. Most recently & very interestingly, there are signs that ARM itself may be willing to start helping out the reverse engineered development[4], which would be a new potentially interesting state of affairs.

[1] http://linux-meson.com/

[2] https://www.phoronix.com/scan.php?page=news_item&px=Bifrost-...

[1] https://forum.libreelec.tv/thread/21134-what-aspects-of-hard...

[4] https://www.phoronix.com/scan.php?page=news_item&px=Arm-Panf...

According to the Armbian (one distro to support them all:^) page, mainline kernel support is complete, although they say there still could be some network problems. From what I read on their forum, the Hardkernel Ubuntu-based image is currently more stable than the Armbian one.

https://www.armbian.com/odroid-n2/ https://forum.armbian.com/search/?q=odroid%20n2%2B&fromCSE=1

https://wiki.odroid.com/getting_started/os_installation_guid...

Dietpi also supports the N2, which is very similar to the N2+. https://dietpi.com/