I did some work on porting miller's work on the risc-v userspace over to 9front, the toolchain works well enough to compile all of /sys/src (at least at the time of its writing). There was some work on a qemu targeted kernel but people lost steam and we never got it booting to userspace.

If you want to check out the userspace parts you can find it here: shithub.us/moody/riscv/HEAD/in…