It took many late nights (and some serious help from GPSFan) but I was eventually able to recreate the environment that GPSFan used to create his modules, and then change it slightly to get things compiled in a static form. Then it was just a matter of getting the tools to cooperate with the Z2. There are quite a few tricks involved in loading things properly, and so I wrote an included script which does everything.
You can download it here: http://www.oddree.com/zipit/alsa-zipitz2.zip
Note that if you get the latest IZ2S image from this site - you will not need these drivers because they are all ready included and loaded by default. This is just provided for folks who want to experiment with the Z2 Shell in it's unadulterated, and naked form.
Here is the included README notes:
alsa-lib/utils-20091113 (snapshot) built for the
Zipit Z2 Shell by Ray Dios Haque on 11/24/2009.
These tools should allow you to use GPSFan's
Z2_Rec modules (playback/recording) on the Z2
Shell, or Rays's Improved Z2 Shell (IZ2S).
More information available on: oddree.com.
For information on how the modules were built,
please see ./orig-notes/readme.
There is a lot going on with this script, and I
wanted to keep it really simple for the purpose
of testing or simply screwing around with your
Zipit. Note that if you are running this every
time you boot your zipit, this is probably a
pretty bad practice and you should consider
giving all of these items a permanent home on
your Z2. Or - just get the latest version of
Ray's Improved Z2 Shell from oddree.com which
will include all of this stuff.
That said, simply run ./loadsound.sh from this
directory to install and activate sound.
The script will remove the native sound driver,
create a few new directories for configuration
files, copy over the needed configuration files,
insert modules into your running system, and
finally will run a command to load up the sound
state from a successful instance of ALSA.
You will need to copy everything in the bin
directory to the bin folder on your SD card.
Now you can play your MP3's. In fact, I have
included a build of mpg123 in the bin directory.
Adjust volume and other things with alsamixer.
Many, many, thanks to my friends GPSFan and
rkdavis from #zipit on irc.freenode.net. We put
in a few late nights to get this going.