{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    nixpkgs-circt162.url = "github:NixOS/nixpkgs/7995cae3ad60e3d6931283d650d7f43d31aaa5c7";
    flake-utils.url = "github:numtide/flake-utils";
    pre-commit-hooks = {
      url = "github:cachix/pre-commit-hooks.nix";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    nur-xin = {
      url = "git+https://git.xinyang.life/xin/nur.git";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    ysyx = {
      url = "github:xinyangli/ysyx-workbench";
    };
  };

  outputs = { self, ... }@inputs: with inputs;
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = import nixpkgs {
          inherit system;
          config.allowUnfree = true;
        };
        rv32CrossConfig = import nixpkgs {
          localSystem = system;
          crossSystem = {
            config = "riscv32-none-elf";
            gcc = {
              abi = "ilp32";
              arch = "rv32if";
            };
          };
        };
      in
      {
        devShells.default = rv32CrossConfig.mkShell {
          nativeBuildInputs = with pkgs; [
            scons
            cmake
            ninja
          ];
          buildInputs = [
            inputs.ysyx.packages.${system}.rv32Cross.abstract-machine
          ];
        };
       }
    );
}