flake.nix

{
  description = "Firmware for the NaxGCC";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-24.05";

    rust-overlay.url = "github:oxalica/rust-overlay";

    flake-utils.url = "github:numtide/flake-utils";

    naersk = {
      url = "github:nmattia/naersk";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs =
    { self
    , nixpkgs
    , rust-overlay
    , flake-utils
    , naersk
    }: (flake-utils.lib.eachDefaultSystem (system:
    let
      pkgs = import nixpkgs {
        inherit system;
        overlays = [
          rust-overlay.overlays.default
        ];
        config.allowUnsupportedSystem = true;
      };

      rustToolchain = pkgs.rust-bin.stable.latest.default.override {
        extensions = [
          "rust-src"
        ];
        targets = [
          "thumbv6m-none-eabi"
        ];
      };

      naersk_lib = naersk.lib.${system}.override {
        cargo = rustToolchain;
        rustc = rustToolchain;
      };

      CARGO_BUILD_TARGET = "thumbv6m-none-eabi";
    in
    {
      packages = {
        default = self.packages.${system}.naxgcc-fw-uf2;

        naxgcc-fw-uf2 = pkgs.runCommandLocal "${self.packages.${system}.naxgcc-fw.pname}-uf2-${self.packages.${system}.naxgcc-fw.version}" { } ''
          mkdir -p $out/bin
          ${pkgs.elf2uf2-rs}/bin/elf2uf2-rs ${self.packages.${system}.naxgcc-fw}/bin/${self.packages.${system}.naxgcc-fw.pname} $out/bin/${self.packages.${system}.naxgcc-fw.pname}.uf2
        '';

        naxgcc-fw = pkgs.callPackage
          ({ mode ? "build" }: naersk_lib.buildPackage {
            pname = (builtins.fromTOML (builtins.readFile ./Cargo.toml)).package.name;
            version = (builtins.fromTOML (builtins.readFile ./Cargo.toml)).package.version;

            inherit mode;

            src = self;

            cargoBuildOptions = _orig: _orig ++ [
              "--target=${CARGO_BUILD_TARGET}"
            ];

            # if a tree falls in the forest and no one is around to hear it, does it make a sound?
            DEFMT_LOG = "off";
          })
          { };
      };

      checks = {
        clippy = self.packages.${system}.naxgcc-fw.override {
          mode = "clippy";
        };
      };

      devShells.default = pkgs.mkShell {
        nativeBuildInputs = builtins.attrValues {
          inherit rustToolchain;
          inherit (pkgs) gcc-arm-embedded elf2uf2-rs picotool probe-rs cargo-expand;
        };

        CARGO_TARGET_THUMBV6M_NONE_EABI_RUNNER = "probe-rs run --chip RP2040 --protocol swd";
        DEFMT_LOG = "debug";

        inherit CARGO_BUILD_TARGET;
      };
    }));
}