Please excuse me i found the mkfatfs command and everything is working perfectly. Please excuse me for disturbing you.
I don't really know very much about eMMC, but the MMC support in NuttX was designed and implemented only for Classic MMC cards. I have heard reports from you and other people that it works with eMMC. But that just shows that they supported backward compatibility with old MMC cards.
My understanding is the eMMC has extensions -- including 4-bit width transfers -- that are not implemented. I suspect that if you really want proper eMMC performance, those extensions would need to be implemented.
Greg
