{
  description = "STM32U575ZI-Q Rust Embedded Development Environment";

  inputs = { nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable"; };

  outputs = { self, nixpkgs }: let
    system = "x86_64-linux";
    pkgs = import nixpkgs { inherit system; };
  in {
    devShells.${system}.default = pkgs.mkShell {
      packages = with pkgs; [
        # Base toolchain
        rustup
        llvm
        gcc
        gnumake
        cmake
        pkg-config
        python3
        git
        curl
        wget
        unzip
	svd2rust
	form

        # ARM embedded cross toolchain
        gcc-arm-embedded

        # Flashing / Debug
        openocd
        probe-rs
        cargo-binutils
        cargo-generate
        flip-link
      ];

      shellHook = ''
        echo ">>> STM32U575ZI-Q Rust (HAL + PAC) DevShell"
        echo "---------------------------------------------"

        # Set up Rust target
        rustup target add thumbv7em-none-eabihf 2>/dev/null || true

        # Ensure probe-rs binary is in PATH
        if ! command -v probe-rs >/dev/null; then
          echo "⚠️ probe-rs not found! (check nix installation)"
        fi

        export RUST_TARGET=thumbv7em-none-eabihf
        export CARGO_TARGET_DIR=target
        export PATH=$PATH:${pkgs.gcc-arm-embedded}/bin

        echo "🧩 Target: $RUST_TARGET"
        echo "💡 Examples:"
        echo "  1️⃣  cargo generate --git https://github.com/rust-embedded/cortex-m-quickstart --name stm32u5-blinky"
        echo "  2️⃣  cd stm32u5-blinky && cargo build --release --target thumbv7em-none-eabihf"
        echo "  3️⃣  probe-rs run --chip STM32U575ZITxQ target/thumbv7em-none-eabihf/release/stm32u5-blinky"
        echo ""
        echo "🧠 TIP: Add stm32u5xx-hal to Cargo.toml to access register-level HAL API."
        echo "---------------------------------------------"

        rustc --version
        arm-none-eabi-gcc --version | head -n1
      '';
    };
  };
}