Run the emulation with:
  
   qemu-system-mips -M malta -kernel output/images/vmlinux -serial stdio -drive file=output/images/rootfs.ext2,format=raw -append "root=/dev/hda" -net nic,model=pcnet -net user
  
  The login prompt will appear in the terminal that started Qemu. The
  graphical window is the framebuffer. No keyboard support has been
  enabled.
  
  Tested with QEMU 2.5.0