From GameBrew - a wiki dedicated to Video Game Homebrew.
I have rebased my Linux port for the 3DS to the latest Linux version (5.9.0-rc5) which was literally released yesterday (September 14th). It took me quite a few hours to get it working but hey, the effort paid off!
[Update] 3DS Linux port updated to 5.9.0-rc5 Linux 5.9.0-rc5 running on a Nintendo 3DS (CTR)
Unfortunately, I'm quite busy these days so I'm writing this post to see if anybody is interested in helping improve the port and write more drivers/features.
Check this for boot instructions and this for build instructions.
Feel free to ping me if you have questions!