Hello Yuri Muhin,
we have a simmilar problem with emmc on our custom board.
We use the seriell Downloader via uart to download uboot. But if we use the mmc dev command to chance to the emmc there is an "Card did not respond to voltage select!" error.
We have no resisters on the CFG Pins. Is it absolutely necessary to have those resistors or burn the fuses to communicate with an eMMC in UBOOT?