Hi, List, I heard through the grape vine that you are considering using NuttX.  I don't want to influence your decision, but if the decision is final, I would like to offer any support to the project that I can give. I have quite a bit of experience working with these TI dual core chips and would be happy to help out as much as possible.  With the ARM7/c5 family, I have developed OS support (uClinux) for the C5471, DSC21, DSC24, and DM270.  Also the DM320 (ARM9/c5, Linux). I founded this business in Costa Rica (http://www.ridgerun.com, also once called Cadenux).  But have not been involved with the more recent ARM11/Cortex A8/c6 chips. There is a porting guide here may be helpful to you: http://nuttx.sourceforge.net/NuttxPortingGuide.html. But it does a some "To be provided" sections -- particulary in the IRQ section. These DSP bridge drivers present interfaces to load programs into the DSP and to support an integrated, seamless messaging system between the ARM7 and the DSP. The DSP interfaces differ from chip to chip and the drivers that I was referring were targeted for uClinux.  However, if that is something you are interested in, I would be happy to do the port a driver and integrate DSP messaging with the NuttX messaging. Greg