{
  description = "ch32fun with devshell.";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-26.05";
  };

  outputs = inputs@{ self, nixpkgs }:
  let
    pkgs = import nixpkgs {
      system = "x86_64-linux";
    };
    riscv32Pkgs = import nixpkgs {
      system = "x86_64-linux";
      crossSystem = {
        system = "riscv32-none-elf";
      };
    };

    ch32fun = pkgs.stdenv.mkDerivation {
      pname = "ch32fun";
      version = "1.0rc2";
      src = pkgs.fetchgit {
        url = "https://github.com/cnlohr/ch32fun.git";
        rev = "72957fb697fe18c875f09126858c94c2590f9ae9";
        hash = "sha256-xaSlC8R3mgSaodOWiRRWkVxcdikoDdSpUN31R2guBR4=";
      };

      buildInputs = with pkgs; [ coreutils udev libusb1 ];

      postUnpack = ''
        export sourceRoot="$sourceRoot/minichlink"
      '';

      installPhase = ''
        runHook preInstall

        mkdir -p $out/{share,src}
        cp -rv ../ch32fun/ $out/src/
        cp -rv ../extralibs/ $out/src/
        cp -rv ../misc/ $out/src/
        rm $out/src/ch32fun/README.md
        sed -i 's/PREFIX_DEFAULT:=riscv64-elf/PREFIX_DEFAULT:=riscv32-unknown-none-elf/' $out/src/ch32fun/ch32fun.mk
        sed -i 's/MINICHLINK?=$(CH32FUN)\/..\/minichlink/MINICHLINK?=$(CH32FUN)\/..\/..\/bin/' $out/src/ch32fun/ch32fun.mk
        sed -i 's/GENERATED_LD_FILE:=$(CH32FUN)\/generated_$(TARGET_MCU_PACKAGE)_$(TARGET_MCU_MEMORY_SPLIT).ld/GENERATED_LD_FILE:=.\/generated_$(TARGET_MCU_PACKAGE)_$(TARGET_MCU_MEMORY_SPLIT).ld/' $out/src/ch32fun/ch32fun.mk

        mkdir -p $out/{bin,lib}
        mkdir -p $out/lib/udev/rules.d
        cp -v minichlink $out/bin
        cp -v minichlink.so $out/lib
        cp -v 99-minichlink.rules $out/lib/udev/rules.d/

        mkdir -p $out/share/{doc,examples}
        ls -al $out/share/doc
        cp -v ../ch32fun/README.md $out/share/doc
        ls -al $out/share/doc
        mv $out/share/doc/README.md $out/share/doc/compability.md
        ls -al $out/share/doc
        cp -v ../README.md $out/share/doc/README.md
        ls -al $out/share/doc
        cp -rv ../examples* $out/share/examples/
        ls -al $out/share/doc

        runHook postInstall
      '';
    };

    whereis-ch32fun = pkgs.writeShellScriptBin "whereis-ch32fun" ''
      echo "${ch32fun}/src/ch32fun"
    '';

    shellProfile = riscv32Pkgs.mkShell {
      name = "WCH ch32";
      packages = [
        pkgs.wlink
        ch32fun
        whereis-ch32fun
      ];
    };
  in
  {
      packages.x86_64-linux.default = ch32fun;
      devShells.x86_64-linux.default = shellProfile;
  };
}