BananPi BPI-P2 zero (H3 chip) fails to boot

Hello,

I have ordered a BananaPi BPI-P2 zero board and I received the version
with an Allwinner H3 chip, not the H2+ one. I followed the steps at

https://wiki.netbsd.org/ports/evbarm/allwinner/

to install NetBSD 9.3 armv7, but unfortunately the board does not
boot. I used the u-boot binary from sysutils/u-boot-bananapi-p2-zero.

U-boot prints three lines over the serial UART, the version, memory
size and that it is unable to boot from MMC1.

Suspect is the H3 chip variant - perhaps the u-boot file is only
suited for the H2+ chip? Apparently there is also just a DTB for the
H2+ model at

https://cdn.netbsd.org/pub/NetBSD/NetBSD-9.3/evbarm-earmv7hf/binary/kernel/

I have also tried some u-boot files for other boards that have the H3
chip and many print some more lines; however all complain that there
is no bootable device. (The same SD card works with Armbian).

Does this sound reasonable? Where do these DTB and u-boot binaries
come from? Anything I could do or try?


Thanks,

Stephan