FreeSmartphone.Org (FSO) developer meeting in Braunschweig

Yesterday I had the pleasure of attending a developer meeting of the FSO core developers Mickey, Daniel, Stefan and Jan in Braunschweig, Germany.

So far my actual involvement with FSO code has been minimal, apart from some profiling here and there, as well as a couple of comments/opinions, mostly offline and not on the mailing lists. I think this is sad, since FSO is the best thing that ever happened inside Openmoko. Focussing on the actual platform/architecture/middleware, standardizing and implementing the interfaces by which application programs interface with the actual device.

So while I haven't been able to contribute much to the python reference implementations, I hope I can contribute a bit more in the future. Also, my involvement with Swisscom Innovations as well as the gnufiish project will probably sooner or later drive me into touching some more FSO code.

It was good to hear the various reports and to see how much thought is given to the various details. Most notably was the quite lengthy debate about how a suitable battery / power supply API should look like. The devil is in the details.

As far as my actual work at the meeting is concerned: I've been asked by the FSO guys to show them how to play back PCM audio into a GSM voice call, and how to record a GSM voice call. Allegedly nobody has ever done this inside Openmoko again, after I demoed it ages ago, most likely still on GTA01.

The resulting information can now be found in the wiki. Unfortunately the actual capture is not working, apparently due to a ASoC driver kernel bug which I tried to debug but gave up after some intermediate results, since my understanding of the audio subsystem is limited and I have tons of other tasks.

The other bit I've been working on is a serial port LED trigger, i.e. the ability to make a LED class device blink if RX or TX activity is detected on a serial port. The code is not finished yet, but will be hopefully soon.

We've also been talking a bit on how to integrate keyboard-based devices with FSO, i.e. how the framework should indicate this to the window manager. The key part is that we're not as much interested in the actual existence of the keyboard, but the fact of whether it is slided out or not (for devices with a slide, such as the glofiish M800 or the TyTN/Kaiser).

Some further bits were spent with Stefan trying to hook up the libertas GSPI driver with the S3C24xx SPI host driver in order to get WiFi to work in project gnufiish.