when installed on the NAND, does OD support USB-storage connection? Usb-gadget is default but what about usb-storage? I know, that it is problematically to turn on usb-storage if the kernel is on SD card, because it must unmount FAT partition on which it's situated.
So, to make usb-storage work, i think, we must install kernel and rootfs on some hidden ext3 partition on the nand and make fat partition on nand mountable/unmountable. That's how original firmware works AFAIR.
Also, is it hard to add some switch to gmenu2x to alter between usb-gadget/usb-storage as GamePark consoles have?
And other question. Are you going to work on the uBoot loader? Maybe you should look towards barebox.org I personally know one guy who is adding jz4740/4755/4770 support to it.
Also it should be nice to add some emus or applications to buildroot and have them compiled and packed to local.tar.gz while building, because otherwise emus are scattered on this forum and links became broken time to time and sources lost (as was with dosbox port to dingoo).