Georg Lukas writes about hacking consumer devices such as Samsung NX cameras, XMPP messaging, networking setups, and firmware reverse engineering.
HN links it for the Samsung NX camera firmware work, including one commenter's pick of its crypto failure post, and for its mobile XMPP critique.
Jabber/XMPP has a number of problems that make it unsuitable for modern chat environments where clients (read: smartphones) have poor connections and frequently want to sleep to conserve power.
For example, XMPP wants an always-on TCP connection between the client and the server for the client to appear "online". There's an extension which allows for sleeping, but having async mobile connections in an extension means that you need the right pair of server and client to enable this feature. Plus, there's no handling of syncing messages between multiple clients. If you've got a smartphone and a desktop client, to compete with Facebook Messenger you need detailed conversation transcripts on both clients -- and an intelligent way to ping your clients and tell which should receive sound notifications.
see more at https://op-co.de/blog/posts/mobile_xmpp_in_2014/
Yeah, I've documented a thing or two about the NX series on https://op-co.de/blog/tags/samsung-nx/
Regarding the RTOS, I took my NX300 from the shelf some weeks ago to make a few shots for the live demo at https://programm.froscon.org/froscon2025/talk/fc37ae17-9264-4549-bbc6-052e699a5625/ and OH MY FSCKING GOD IT'S SLOW! I made a burst shot of a model train approaching, and the camera was busy processing it for multiple minutes. The NX500 is lightning fast in comparison, and the NX1 is even snappier.
So what do you plan to do with the ARM hook? I've poked at different places of di-camera-binary, but never at the processing pipeline, and there are soooo many things to reverse-engineer, and I'm but one person!
A lot of the "smarter" cameras already are running Linux; here is an example (more of a "look at how bad the security is" post, but you get the idea):
http://op-co.de/blog/posts/hacking_the_nx300/
Personally I think this is a fun hack that shows how much processing power the hardware has, but I wouldn't want to run a full OS on my camera...
Though as described here: http://op-co.de/blog/posts/mobile_xmpp_in_2014/#index2h2 -- Message Carbons don't help if your phone is out of coverage for a few minutes, as your desktop client will get the carbons, but when you come back online, you'll be oblivious to any messages sent during that time.
They are proper cameras, with proper camera-sized sensors, and some model had interchangable lenses. One of them, for better or for worse, even came with Android. https://op-co.de/blog/posts/galaxy_nx/
I liked https://op-co.de/blog/posts/samsung_nx_cryptofail/#index3h3 more. Absolute astonishing firmware "crypto" fail