kumquat-buildroot/board/qemu/riscv64-virt
..
readme.txt

Run Linux in emulation with:

  qemu-system-riscv64 -M virt -kernel output/images/fw_jump.elf -device loader,file=output/images/Image,addr=0x80200000 -append "root=/dev/vda ro" -drive file=output/images/rootfs.ext2,format=raw,id=hd0 -device virtio-blk-device,drive=hd0 -netdev user,id=net0 -device virtio-net-device,netdev=net0 -nographic

The login prompt will appear in the terminal that started Qemu.

Tested with QEMU 3.1