[Zigurd]

Way back when a wrote a couple chapters for Android Application Development I wrote about Android's RIL daemon and the underlying device-specific RIL libraries. It's gotten a lot more complicated, but the source code is open and includes what appears to be a reference implementation: https://github.com/android/platform_hardware_ril

I have not looked at this part of Android source code in depth in a while, but from a quick look it still looks very edifying about how this part of a smartphone works.

[reubenmorais]

Similarly, the open source implementation of the Firefox OS RIL daemon can be read here: https://mxr.mozilla.org/mozilla-central/source/dom/system/go...

(Sadly, it's not used in all production devices.)

[Zigurd]

That's a lot of code! I wonder if it has more feature coverage than the Android device-independent RIL layer.

[tmzt]

Have you documented the RPCs to the modem as well?