head -r357356: fails to boot RPi4 but boots Rock64 (same media, moved between machines); -r356426 booted both

[Klaus Küchemann]

Mark Millard,

I currently don’t know if that could solve the mmc rescan-issue for the RPI4, but

Because I'm running out of time ... perhaps you are able and have time to test patch :
https://reviews.freebsd.org/D15955
on the RPI4.
I guess that assumes you compile to GENERIC-MMCCAM 
If you’re hanging on panic with RPI4 for now 
You can simply  xx#mv kernel.old kernel  on your Rock64
… as said: I currently don’t know if D15955 could fix it...

Regards 
Klaus