I am using 4 GB eMMC at the moment , and so far it is working perfectly. Nuttx is recognizing the eMMC it is able to format it in FAT and now i am able to mount it , read and write in it, so so far i have no problems at all with the eMMC. THe only thing is that i use 1 wire setup so , I am not using the full speed which eMMC can offer but for my case that is okay. Later on i am planning to add also the Fast modes and 4 wire and 8 wire support.
I believe you will need some modifications to the MMC/SD driver when you need the fast mode and wide bus support.
But I am glad to hear that it is meeting your needs as it is for now. Greg
