qemu-system-riscv64 `
  -nographic -machine virt `
  -smp 2 -m 4G `
  -kernel fw_payload_oe.elf `
  -drive file=openEuler-preview.riscv64.qcow2,format=qcow2,id=hd0 `
  -device virtio-blk-device,drive=hd0 `
  -device virtio-net-device,netdev=usernet `
  -netdev user,id=usernet,hostfwd=tcp::12055-:22 `
  -append 'root=/dev/vda1 rw console=ttyS0 systemd.default_timeout_start_sec=600 selinux=0 highres=off mem=4096M earlycon' `
  -bios none