I saw a blog post on Sparkfun (that appears to have subsequently been removed) that the Edison SOM includes a Quark MCU that is currently not used, but there is plans to enable it in the future. I'm not sure what this means, since all he I/O pins are already used. My only guess would be that some of the I/O pins are actually connected to the MCU, and the MCU firmware(?) is not currently user programmable, but might be in the future.
Could someone provide more insight into this if this is true? I'm currently designing a custom board that adds an MCU, primarily to get more PWM (like) inputs/outputs. If it might be possible to control some more of the GPIO pins from an on-board MCU, this might not be necessary.