Update README

README.md

@@ -1,7 +1,13 @@
 # NixOS on RISC-V
 
-For now let's try to boot it in qemu.
+To boot the system in QEMU, first enter the development shell:
 
-    $ nix build .#nixosConfigurations.visionfive-cross.config.system.build.vm
+```
+$ nix develop
+```
 
-That would cross-build a bootable RISC-V qemu VM from x86.
+Then run the boot script:
+
+```
+$ ./boot.sh
+```