Since I do some embedded programming I'd like to poke around and write a dedicated network operating system. Yes I know a ambitious goal but I am familiar with bit shifting and datasheet digging. For easy development I guess booting over LAN will be fastest iteration method.
Must have:
serial port
arm core (eventually MIPS)
cpu datasheet (best with optional e.g. switch chip datasheet)
at least 2 ethernet ports (more better)
What board would you recommend which is easiest to hack ?
This is the OpenWrt forum, the only OS that is discussed here is OpenWrt based on the Linux kernel.
That said:
You did not mention wireless - required?
I'd first decide which target to use, based on the availability of datasheets. Check if you can find complete Mediatek, Realtek or QCA datasheets, they seem to be the most active targets at the moment.
Wireless is not required. If datasheet is available then I'd use it. I've looked at hardware list but couldn't find any datasheets. I've found only AR9331 datasheet.