As I don't have any M-class gear myself, I have to rely on the info
given in the mailing list threads mentioned on [1]. Though it will never
hurt to try again if you have the hardware, as the threads were already
from late 2017 and 2015 respectively. Things might be different now,
although I have my doubts.
[1]: https://wiki.debian.org/Sparc64#Installing_the_Debian_SPARC64_Port
Never hurts to try. At most, a coffee pot may be needed.
Or does one need to do a cross compile from some other platform of a
kernel?
No I don't think so. I believe support for Fujitsu's SPARC64 processors
and accompanying chipsets is just missing in the Linux kernel currently.
Well damn. I have both M3000 and M4000 gear as well as many many older
sparc type units. I think I should grab an old old unit and try there
first as those chips and motherboards have been around forever.
Dennis