As planned, today PlayStation 4 hacker Marcan of Fail0verflow covered how they reverse-engineered Sony's PS4 console via FreeBSD / Sandbox to install PS4 Linux on it at Chaos Computer Club (CCC) 2016 alongside a Portal 2 Steam (older Demo / Guide) PS4 demonstration video below on Firmware 4.05! 
According to @Joonie of Team Rebug, PlayStation 4 developer @flatz got PS4 Linux running on Firmware 4.05 day 1 too!
Here are some of the related Tweets and files / links / videos:
Download: bonaire.rai.txt
Fail0verflow Links:
Fail0verflow CCC 2016 Slide Links:
https://github.com/fail0verflow/ps4-kexec
While fail0verflow stated that due to the 'drama' that comes along with it they aren't going to be the ones to provide PS4 exploits that may lead to backups on the PlayStation 4 (especially after what Sony did to GeoHot), scene release group TRSi is still active and there are some very interesting things happening HERE so it's best to stay at 4.05 or below although not all developers agree.
PCI Express DIY Hacking Toolkit for Xilinx SP605 via Dmytro Oleksiuk
Thanks to @DoxyMarket, @kazookid0, @MrBone, @MrNiato and @VultraAID in the PSXHAX Shoutbox for help with this article! 
According to @Joonie of Team Rebug, PlayStation 4 developer @flatz got PS4 Linux running on Firmware 4.05 day 1 too!
Here are some of the related Tweets and files / links / videos:
Fail0verflow CCC 2016 Slide Links:
https://github.com/fail0verflow/ps4-kexec
- kexec and hardware reconfiguration / "bootloader" code
- Kernel tree
- Userspace library patches
- f32dis and RAI tools
- https://media.ccc.de/c/33c3
- https://fail0verflow.com/media/33c3-slides/#/
- https://dellinger.alb.c3voc.de/s1_native_hd.webm