Good news. 
I compiled a test image of Ubuntu server 20171201 with the latest version of the kernel 4.x and mainline u-boot (the file u-boot collected @numbqq).
The necessary patches to build u-boot provided by @narmstrong
After adding a new version of u-boot on the SD card,
dd if=u-boot.bin.sd.bin of=/dev/mmcblkX conv=fsync,notrunc bs=1 count=444
dd if=u-boot.bin.sd.bin of=/dev/mmcblkX conv=fsync,notrunc bs=512 skip=1 seek=1
and adding a file boot.scr system normally runs on the VIM2. Is output to the screen runs the console UART and a working wired network (can use SSH).
All the necessary files and the image can be found at this link.