I have not been able to find any information in the freescale documentation for how to record audio from the built-in microphone on the SABRE-SDB board. I came across a webpage: How to use & access iMX6 peripherals (Examples) - iMX6 Rex Module and it showed examples of how to record from microphone;
# arecord -f dat -d 10 -D hw:0,0 test.wav
Play the recorded file:
# aplay -f dat test.wav
After booting the board I am able to record. However, when I playback, I do not hear anything coming out of my headset. I am booting for the SD card image that came with the board.
P.S. Where is the test.wav file stored?