You shouldn't need a serial connection. You can prepare a bootable micro-sd card. Boot from that first.
Have you seen this? https://github.com/jasperla/openbsd-rockpro64
I run NetBSD and I don't have any experience with OpenBSD. But I think installation would be similar. I made a bootable micro-sd and then copied the first part of that to eMMC and then installed NetBSD.
I used NetBSD for the micro-SD (and you could too, since the pre-built images are so easy to use). But you could use Linux or anything else, too. Then install OpenBSD to the eMMC.
Have you seen this? https://github.com/jasperla/openbsd-rockpro64
I run NetBSD and I don't have any experience with OpenBSD. But I think installation would be similar. I made a bootable micro-sd and then copied the first part of that to eMMC and then installed NetBSD.
I used NetBSD for the micro-SD (and you could too, since the pre-built images are so easy to use). But you could use Linux or anything else, too. Then install OpenBSD to the eMMC.
:wq
[ SRA accepts you ]
[ SRA accepts you ]
