Recently, we ran into a serious issue - namely, how exactly to go about allocating IP addresses to nodes, in a way that satisfies all properties needed of this project - easy to set up, little-to-no maintenance, ¿?fault tolerant, and generally out of the way. This immediately put out static IP addresses, due to its difficulty to orchestrate, and increased knowledge required. It also, however, eliminates DHCP, due to the fact that it requires a single point of failure - namely, the DHCP server itself.

Given this, we've got a tradeoff to make, right? Do we sacrifice ease of setting up, or fault tolerance? Honestly, I'd sooner keep both, given the chance. So, that's what we've set out to do - build a system that can dynamically allocate addressing schemes, that is fault tolerant, and fully automatic - that is to say, requires no maintenance, set up, or anything else end users really do NOT want to be doing.

This leaves us with 3 tasks - get compilation working on OpenWRT, so we can write software for it, write a protocol capable of performing this role, and write the software for OpenWRT to implement the protocol. This post will deal with the first of the three tasks, the end result of which will be a "Hello World" implementation running on the router.

Fairly obviously, I'll need a cross development system. Already I'm apprehensive, after what happened *last* time (and believe me when I say, there was a lot more to that story than I posted about; it was heavily condensed). Turns out, though, that the fine people who develop OpenWRT release an SDK - a toolchain, and packaging system rolled into one, that requires hardly any work to set up and use, or so the theory goes in any case.

They do have the SDK released as a bzipped tarball on their site, under downloads, for exactly the processor I'm compiling for. Surely it can't be as easy as that? Nope, 'fraid not. Turns out they only release their toolchains, and SDKs, for x86_64. I still use 32 bit, as I can't be bothered to go through the rigmarole of reinstalling an OS, just to double the amount of bits I get (and given the fact that I only have 2GB of RAM anyway, what's the point?)

So, in light of this, I need to search out the SDK from elsewhere - which means compiling the Buildroot system. Thought I'd gotten away with it, too. So I download this, update the feeds, and enter the menuconfig. I check the box saying "Build SDK" (or words to that effect), and run make. It builds, and I cannot find the SDK. Anywhere.

I go back into the menuconfig, and check "Build Toolchain", and remake it. Then I find the SDK. In the one place I didn't look. D'oh. I get this installed on my system, and write a simple "Hello world" application, with the makefiles associated (you need 2 - one for the environment setup, and one to actually build the thing). Running the SDK on this yielded me a package, which itself took me all my time to find.

I SCP this onto the router, fairly painlessly, and use ipkg to install it, only to find there is no ipkg on my router. This time, it's fairly simple: I was using outdated instructions, and since then, they've renamed ipkg to opkg. Using this, I install my newly minted package, successfully this time. Now for the real test.

root@OpenWrt:~# helloworld
Hello, world!
root@OpenWrt:~# 

Success! Never thought I'd be quite so happy to get hello world running.