I discovered a document from ST describing how to implement signal generation and .wav playing via the DAC in the STM32 series (Cerb*). There’s even sample code for the signal generation. The best part is that the signal generator is non-blocking, so your code can go on its merry way while the signal is output.
The document is here:
The sample code is here (in the DAC_SignalsGeneration project):
http://www.st.com/internet/com/SOFTWARE_RESOURCES/SW_COMPONENT/FIRMWARE/stm32f0discovery_fw.zip
This would make a great addition to the OSHW firmware!