{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    nixpkgs-stable.url = "github:NixOS/nixpkgs/nixos-24.05";
    nixpkgs-circt162.url = "github:NixOS/nixpkgs/7995cae3ad60e3d6931283d650d7f43d31aaa5c7";
    nur-xin = {
      url = "git+https://git.xinyang.life/xin/nur.git";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    flake-utils.url = "github:numtide/flake-utils";
    sbt-derivation = {
      url = "github:zaninime/sbt-derivation";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    am-kernels.url = "git+https://git.xinyang.life/xin/am-kernels.git?ref=dev";
  };

  outputs = { self, nixpkgs, nixpkgs-stable, flake-utils, nur-xin, nixpkgs-circt162, sbt-derivation, am-kernels }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        stablePkgs = import nixpkgs-stable {
          inherit system;
          config.allowUnfree = true;
          overlays = [
          ];
        };
        pkgs = import nixpkgs {
          inherit system;
          config.allowUnfree = true;
          overlays = [
            (self: super: {
              nvboard = nur-xin.legacyPackages.${system}.nvboard;
              mini-gdbstub = nur-xin.legacyPackages.${system}.mini-gdbstub;
            })
          ];
        };
      in
      {
        packages = rec {
          flow = pkgs.callPackage ./flow.nix {
            inherit (sbt-derivation.lib) mkSbtDerivation;
          };

          flow-simlib = pkgs.callPackage ./flow-simlib.nix {
            inherit flow;
          };
        };

        devShells.default = pkgs.mkShell.override { stdenv = pkgs.ccacheStdenv; } {
          nativeBuildInputs = with pkgs; [
            cmake
            ninja
            flex
            bison
            nvboard
            flow
            espresso
            coursier
            sbt-with-scala-native
            gef
          ] ++ [stablePkgs.verilator];
          CHISEL_FIRTOOL_PATH = "${nixpkgs-circt162.legacyPackages.${system}.circt}/bin";
          NPC_IMAGES_PATH = "${am-kernels.packages.${system}.rv32Cross.am-kernels-npc}/share";

          buildInputs = with pkgs; [
            cli11
            spdlog
            mini-gdbstub
          ];
        };
      });
}