Hi Jacky:
A DO-178b certification package for MQX unfortunately does not exist, though it would be nice to have one. Some time ago licensees of MQX have certified products to the do-178 standard, so a product can be certified using MQX, but you do need to look at the different level of certification. To my knowledge MQX could not be certified to the highest level (level A) but it could for one of the lower levels (B through D).
I would suggest you contact the owner of MQX , Embedded Access Inc. directly for more details.
Regards
Daniel