There are some other open OSs, like Zephyr, NuttX and Contiki - so maybe they're the right thing to use for the nommu case rather than Linux?
Zephyr is not an OS in the conventional sense, it's more a library you link to so the application can "go".
xv6 already runs on RISC-V.
Zephyr is not an OS in the conventional sense, it's more a library you link to so the application can "go".