George Hilliard

I really enjoyed reading this, especially the little branches off into other useful topics and tools. Here are my notes as a summary:

Good blog write up about reversing Reolink B800 IP camera
end result: https://github.com/thirtythreeforty/neolink

tools used:

* wireshark & dissector in Lua https://mika-s.github.io/wireshark/lua/dissector/2017/11/04/creating-a-wireshark-dissector-in-lua-1.html

* binwalk

* visualize the BIN for blank space, code, etc. https://binvis.io/#/

* buildroot to make custom: gdbserver, busybox with all the fixin’s, and strace

* disassemble / decompile MIPS with https://ghidra-sre.org/

* using tcpsvd as tcp wrapper for FTPD in custom image

* quick setup env with "expect" script: https://www.thirtythreeforty.net/posts/2020/05/hacking-reolink-cameras-for-fun-and-profit/start-debug.exp

* using gdb Dynamic Print commands to target certain functions.
The dynamic printf command dprintf combines a breakpoint with formatted printing of your program’s data to give you the effect of inserting printf calls into your program on-the-fly, without having to recompile it. https://doc.ecoscentric.com/gnutools/doc/gdb/Dynamic-Printf.html

* busybox has a watchdog minder, used like: watchdog /dev/watchdog

* background info on Baichuan protocol

* wrote new client software in Rust. https://github.com/thirtythreeforty/neolink/blob/master/src/main.rs

* Gstreamer with RTSP server (in Rust!)

* using it with Blue Iris nvr software

I honestly feel like building something like a PDA would be easier using a bespoke layout. You can entirely remove stuff you don't need (like, say, the VPU (lol)) and save battery life. You can also optimize for what you're actually going to be using, eg once you've selected the type of display you can just support the type of interface it will use (SPI perhaps), etc.

FWIW, the Allwinner F1C100s is ~$2, 533MHz, has 32MB RAM onboard, and can run mainline recent Linux. It's also this easy* to plonk onto a PCB: https://www.thirtythreeforty.net/posts/2019/12/my-business-card-runs-linux/

(* Yes, "easy" is relative. You'll need a few interesting tools and it'll be a tad deer-in-headlights. But you don't need a rocket science degree to even fathom the idea.)

Not sure who was first(as the article linked isn't dated), but remember seeing something a few years back that someone else created as a business Linux card

Tracked it down: https://hackaday.com/2019/12/24/now-even-your-business-card-can-run-linux/

https://www.thirtythreeforty.net/posts/2019/12/my-business-card-runs-linux/

This design looks better.

Both creative

Edit: somehow I duplicate posted when I edited my last comment, qchris beat me to posting this (and was on HN in 2019, I think I probably saw it on hackaday at the time)

Good read!

Some others that I have enjoined in the embedded Linux realm are the posts by George Hilliard, Mastering Embedded Linux series and the Designing my Linux-powered Business Card.

https://www.thirtythreeforty.net/posts/2019/08/mastering-embedded-linux-part-1-concepts/

https://www.thirtythreeforty.net/posts/2019/12/designing-my-linux-business-card/