add devShell

flake.nix

@@ -7,10 +7,32 @@
       value = import "${base}/${name}";
     }) (builtins.readDir base);
 
+    sdk = fetch: fetch {
+      owner = "NessieCircuits";
+      repo = "Riotee_SDK";
+      tag = "v1.2.0";
+      hash = "sha256-1ZFvbGiTzAuBnKGUe/MAAI4D+d+jl/LCLcYqthkxB5M=";
+    };
+
     packages = let
       packages = scan ./packages;
     in system: pkgs: builtins.mapAttrs (_: fn: pkgs.callPackage fn {}) packages;
+
+    devShells = system: pkgs: {
+      default = pkgs.mkShell {
+        buildInputs = with pkgs; [
+          self.packages.${system}.riotee-probe
+          gnumake
+          gcc-arm-embedded
+        ];
+        shellHook = ''
+          export RIOTEE_SDK_ROOT="${sdk pkgs.fetchFromGitHub}"
+        '';
+      };
+    };
+
   in {
     packages = builtins.mapAttrs packages nixpkgs.legacyPackages;
+    devShells = builtins.mapAttrs devShells nixpkgs.legacyPackages;
   };
 }