The Audio on the baseboard is routed through the twl4030 PMIC.
When the audio driver is loaded 'omap-twl4030 sound: twl4030-hifi <-> 49022000.mcbsp mapping ok' should appear in dmesg.
In order to use the audio, the alsa packages need to be installed.
From the buildroot directory: type make menuconfig
Target Packages - > Audio and Video Applications -> alsa-utils
Leave the default options selected and add alsamixer, aplay and speaker test
Build (make) buildroot with the new packages and install.
Boot the board with the new files added.
By default, the audio device is muted.
run alsamixer and locate Headset L1 and Headset R1 and unmute both by selecting each and pressing the 'm' button
Adjust DCA2 Analog to approximately 50 and DAC2 Digital Fine between 50-75 and Headset to about 67. These settings can be adjusted for personal preference.
Exit the mixer
Connect headphones to the Line Out jack on the basebase
Run the speaker test to hear the audio.
speaker-test -t wave -c2
-t wave will play a voice indicating which channel is playing
-c2 will specify stereo (ie, front left, front right)