{
  description = "ARTIQ port to the Zynq-7000 platform";

  inputs.artiq.url = git+https://github.com/m-labs/artiq.git?ref=release-7;
  inputs.mozilla-overlay = { url = github:mozilla/nixpkgs-mozilla; flake = false; };
  inputs.zynq-rs.url = git+https://git.m-labs.hk/m-labs/zynq-rs;
  inputs.zynq-rs.inputs.nixpkgs.follows = "artiq/nixpkgs";

  outputs = { self, mozilla-overlay, zynq-rs, artiq }:
  let
    pkgs = import artiq.inputs.nixpkgs { system = "x86_64-linux"; overlays = [ (import mozilla-overlay) ]; };
    zynqpkgs = zynq-rs.packages.x86_64-linux;
    artiqpkgs = artiq.packages.x86_64-linux;

    rustPlatform = zynq-rs.rustPlatform;

    fastnumbers = pkgs.python3Packages.buildPythonPackage rec {
      pname = "fastnumbers";
      version = "2.2.1";

      src = pkgs.python3Packages.fetchPypi {
        inherit pname version;
        sha256 = "0j15i54p7nri6hkzn1wal9pxri4pgql01wgjccig6ar0v5jjbvsy";
      };
    };

    artiq-netboot = pkgs.python3Packages.buildPythonPackage rec {
      pname = "artiq-netboot";
      version = "unstable-2020-10-15";

      src = pkgs.fetchgit {
        url = "https://git.m-labs.hk/m-labs/artiq-netboot.git";
        rev = "04f69eb07df73abe4b89fde2c24084f7664f2104";
        sha256 = "0ql4fr8m8gpb2yql8aqsdqsssxb8zqd6l65kl1f6s9845zy7shs9";
      };
    };

    ramda = pkgs.python3Packages.buildPythonPackage {
      pname = "ramda";
      version = "unstable-2019-02-01";

      src = pkgs.fetchFromGitHub {
        owner = "peteut";
        repo = "ramda.py";
        rev = "bd58f8e69d0e9a713d9c1f286a1ac5e5603956b1";
        sha256 = "0qzd5yp9lbaham8p1wiymdjapzbqsli7lvngv24c3z4ybd9jlq9g";
      };

      nativeBuildInputs = with pkgs.python3Packages; [ pbr ];
      propagatedBuildInputs = with pkgs.python3Packages; [ future fastnumbers ];

      checkInputs = with pkgs.python3Packages; [ pytest pytest-flake8 ];
      checkPhase = "pytest";
      doCheck = false;

      preBuild = ''
        export PBR_VERSION=0.0.1
      '';
    };

    migen-axi = pkgs.python3Packages.buildPythonPackage {
      pname = "migen-axi";
      version = "unstable-2021-09-15";

      src = pkgs.fetchFromGitHub {
        owner = "peteut";
        repo = "migen-axi";
        rev = "9763505ee96acd7572280a2d1233721342dc7c3f";
        sha256 = "15c7g05n183rka66fl1glzp6h7xjlpy1p6k8biry24dangsmxmvg";
      };

      nativeBuildInputs = with pkgs.python3Packages; [ pbr ];
      propagatedBuildInputs = with pkgs.python3Packages; [ setuptools click numpy toolz jinja2 ramda artiqpkgs.migen artiqpkgs.misoc ];

      postPatch = ''
        substituteInPlace requirements.txt \
          --replace "jinja2==2.11.3" "jinja2"
        substituteInPlace requirements.txt \
          --replace "future==0.18.2" "future"
        substituteInPlace requirements.txt \
          --replace "ramda==0.5.5" "ramda"
        substituteInPlace requirements.txt \
          --replace "colorama==0.4.3" "colorama"
        substituteInPlace requirements.txt \
          --replace "toolz==0.10.0" "toolz"
        substituteInPlace requirements.txt \
          --replace "pyserial==3.4" "pyserial"
        substituteInPlace requirements.txt \
          --replace "markupsafe==1.1.1" "markupsafe"
      '';

      checkInputs = with pkgs.python3Packages; [ pytest pytest-timeout pytest-flake8 ];
      checkPhase = "pytest";

      preBuild = ''
        export PBR_VERSION=0.0.1
      '';
    };
    binutils = { platform, target, zlib }: pkgs.stdenv.mkDerivation rec {
      basename = "binutils";
      version = "2.30";
      name = "${basename}-${platform}-${version}";
      src = pkgs.fetchurl {
        url = "https://ftp.gnu.org/gnu/binutils/binutils-${version}.tar.bz2";
        sha256 = "028cklfqaab24glva1ks2aqa1zxa6w6xmc8q34zs1sb7h22dxspg";
      };
      configureFlags =
        [ "--enable-shared" "--enable-deterministic-archives" "--target=${target}"];
      outputs = [ "out" "info" "man" ];
      depsBuildBuild = [ pkgs.buildPackages.stdenv.cc ];
      buildInputs = [ zlib ];
      enableParallelBuilding = true;
    };
    binutils-arm = pkgs.callPackage binutils { platform = "arm"; target = "armv7-unknown-linux-gnueabihf"; };

    # FSBL configuration supplied by Vivado 2020.1 for these boards:
    fsblTargets = ["zc702" "zc706" "zed"];
    sat_variants = [
      # kasli-soc satellite variants
      "satellite"
      # zc706 satellite variants
      "nist_clock_satellite" "nist_qc2_satellite" "acpki_nist_clock_satellite" "acpki_nist_qc2_satellite" 
      "nist_clock_satellite_100mhz" "nist_qc2_satellite_100mhz" "acpki_nist_clock_satellite_100mhz" "acpki_nist_qc2_satellite_100mhz"
    ];
    build = { target, variant, json ? null }: let
      szl = zynqpkgs."${target}-szl";
      fsbl = zynqpkgs."${target}-fsbl";
      fwtype = if builtins.elem variant sat_variants then "satman" else "runtime";

      firmware = rustPlatform.buildRustPackage rec {

        name = "firmware";
        src = ./src;
        cargoLock = { 
          lockFile = src/Cargo.lock;
          outputHashes = {
            "libasync-0.0.0" = "sha256-p89w9eoFJ2VFTDZ5Mrv5vsH0E1Ko9z1C6Ett281hCHg=";
          };
        };

        nativeBuildInputs = [
          pkgs.gnumake
          (pkgs.python3.withPackages(ps: (with artiqpkgs; [ ps.jsonschema migen migen-axi misoc artiq ])))
          artiqpkgs.artiq
          zynqpkgs.cargo-xbuild
          pkgs.llvmPackages_9.llvm
          pkgs.llvmPackages_9.clang-unwrapped
        ];
        buildPhase = ''
          export XARGO_RUST_SRC="${rustPlatform.rust.rustc}/lib/rustlib/src/rust/library"
          export CLANG_EXTRA_INCLUDE_DIR="${pkgs.llvmPackages_9.clang-unwrapped.lib}/lib/clang/9.0.1/include"
          export CARGO_HOME=$(mktemp -d cargo-home.XXX)
          make TARGET=${target} GWARGS="${if json == null then "-V ${variant}" else json}" ${fwtype}
        '';

        installPhase = ''
          mkdir -p $out $out/nix-support
          cp ../build/${fwtype}.bin $out/${fwtype}.bin
          cp ../build/firmware/armv7-none-eabihf/release/${fwtype} $out/${fwtype}.elf
          echo file binary-dist $out/${fwtype}.bin >> $out/nix-support/hydra-build-products
          echo file binary-dist $out/${fwtype}.elf >> $out/nix-support/hydra-build-products
        '';

        doCheck = false;
        dontFixup = true;
      };
      gateware = pkgs.runCommand "${target}-${variant}-gateware"
        {
          nativeBuildInputs = [ 
            (pkgs.python3.withPackages(ps: (with artiqpkgs; [ ps.jsonschema migen migen-axi misoc artiq ])))
            artiqpkgs.artiq
            artiqpkgs.vivado
          ];
        }
        ''
          python ${./src/gateware}/${target}.py -g build ${if json == null then "-V ${variant}" else json}
          mkdir -p $out $out/nix-support
          cp build/top.bit $out
          echo file binary-dist $out/top.bit >> $out/nix-support/hydra-build-products
        '';

      # SZL startup
      jtag = pkgs.runCommand "${target}-${variant}-jtag" {}
        ''
          mkdir $out
          ln -s ${szl}/szl.elf $out
          ln -s ${firmware}/${fwtype}.bin $out
          ln -s ${gateware}/top.bit $out
        '';
      sd = pkgs.runCommand "${target}-${variant}-sd"
        {
          buildInputs = [ zynqpkgs.mkbootimage ];
        }
        ''
          # Do not use "long" paths in boot.bif, because embedded developers
          # can't write software (mkbootimage will segfault).
          bifdir=`mktemp -d`
          cd $bifdir
          ln -s ${szl}/szl.elf szl.elf
          ln -s ${firmware}/${fwtype}.elf ${fwtype}.elf
          ln -s ${gateware}/top.bit top.bit
          cat > boot.bif << EOF
          the_ROM_image:
          {
            [bootloader]szl.elf
            top.bit
            ${fwtype}.elf
          }
          EOF
          mkdir $out $out/nix-support
          mkbootimage boot.bif $out/boot.bin
          echo file binary-dist $out/boot.bin >> $out/nix-support/hydra-build-products
        '';

      # FSBL startup
      fsbl-sd = pkgs.runCommand "${target}-${variant}-fsbl-sd"
        {
          buildInputs = [ zynqpkgs.mkbootimage ];
        }
        ''
          bifdir=`mktemp -d`
          cd $bifdir
          ln -s ${fsbl}/fsbl.elf fsbl.elf
          ln -s ${gateware}/top.bit top.bit
          ln -s ${firmware}/${fwtype}.elf ${fwtype}.elf
          cat > boot.bif << EOF
          the_ROM_image:
          {
            [bootloader]fsbl.elf
            top.bit
            ${fwtype}.elf
          }
          EOF
          mkdir $out $out/nix-support
          mkbootimage boot.bif $out/boot.bin
          echo file binary-dist $out/boot.bin >> $out/nix-support/hydra-build-products
        '';
    in {
      "${target}-${variant}-firmware" = firmware;
      "${target}-${variant}-gateware" = gateware;
      "${target}-${variant}-jtag" = jtag;
      "${target}-${variant}-sd" = sd;
    } // (
      if builtins.elem target fsblTargets
      then {
        "${target}-${variant}-fsbl-sd" = fsbl-sd;
      }
      else {}
    );

    gateware-sim = pkgs.stdenv.mkDerivation {
      name = "gateware-sim";
      
      nativeBuildInputs = [ 
        (pkgs.python3.withPackages(ps: (with artiqpkgs; [ migen migen-axi artiq ]))) 
        artiqpkgs.artiq
      ];

      phases = [ "buildPhase" ];

      buildPhase =
        ''
        python -m unittest discover ${self}/src/gateware -v
        touch $out
        '';
    };

    # for hitl-tests
    zc706-nist_qc2 = (build { target = "zc706"; variant = "nist_qc2"; });
    zc706-hitl-tests = pkgs.stdenv.mkDerivation {
      name = "zc706-hitl-tests";

      __networked = true;  # compatibility with old patched Nix
      # breaks hydra, https://github.com/NixOS/hydra/issues/1216
      #__impure = true;     # Nix 2.8+

      buildInputs = [
        pkgs.netcat pkgs.openssh pkgs.rsync artiqpkgs.artiq artiq-netboot zynqpkgs.zc706-szl
      ];
      phases = [ "buildPhase" ];

      buildPhase =
        ''
        export NIX_SSHOPTS="-F /dev/null -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o LogLevel=ERROR -i /opt/hydra_id_ed25519"
        LOCKCTL=$(mktemp -d)
        mkfifo $LOCKCTL/lockctl

        cat $LOCKCTL/lockctl | ${pkgs.openssh}/bin/ssh \
        $NIX_SSHOPTS \
        rpi-4 \
        'mkdir -p /tmp/board_lock && flock /tmp/board_lock/zc706-1 -c "echo Ok; cat"' \
        | (
          # End remote flock via FIFO
          atexit_unlock() {
            echo > $LOCKCTL/lockctl
          }
          trap atexit_unlock EXIT

          # Read "Ok" line when remote successfully locked
          read LOCK_OK

          echo Power cycling board...
          (echo b; sleep 5; echo B; sleep 5) | nc -N -w6 192.168.1.31 3131
          echo Power cycle done.

          export USER=hydra
          export OPENOCD_ZYNQ=${zynq-rs}/openocd
          export SZL=${zynqpkgs.szl}
          bash ${self}/remote_run.sh -h rpi-4 -o "$NIX_SSHOPTS" -d ${zc706-nist_qc2.zc706-nist_qc2-jtag}

          echo Waiting for the firmware to boot...
          sleep 15

          echo Running test kernel...
          artiq_run --device-db ${self}/examples/device_db.py ${self}/examples/mandelbrot.py

          echo Running ARTIQ unit tests...
          export ARTIQ_ROOT=${self}/examples
          export ARTIQ_LOW_LATENCY=1
          python -m unittest discover artiq.test.coredevice -v

          touch $out

          echo Completed

          (echo b; sleep 5) | nc -N -w6 192.168.1.31 3131
          echo Board powered off
        )
        '';
    };
  in rec {
    packages.x86_64-linux = (build { target = "zc706"; variant = "nist_clock"; }) //
      (build { target = "zc706"; variant = "nist_clock_master"; }) //
      (build { target = "zc706"; variant = "nist_clock_satellite"; }) //
      (build { target = "zc706"; variant = "nist_clock_satellite_100mhz"; }) //
      (build { target = "zc706"; variant = "nist_qc2"; }) //
      (build { target = "zc706"; variant = "nist_qc2_master"; }) //
      (build { target = "zc706"; variant = "nist_qc2_satellite"; }) //
      (build { target = "zc706"; variant = "nist_qc2_satellite_100mhz"; }) //
      (build { target = "zc706"; variant = "acpki_nist_clock"; }) //
      (build { target = "zc706"; variant = "acpki_nist_clock_master"; }) //
      (build { target = "zc706"; variant = "acpki_nist_clock_satellite"; }) //
      (build { target = "zc706"; variant = "acpki_nist_clock_satellite_100mhz"; }) //
      (build { target = "zc706"; variant = "acpki_nist_qc2"; }) //
      (build { target = "zc706"; variant = "acpki_nist_qc2_master"; }) //
      (build { target = "zc706"; variant = "acpki_nist_qc2_satellite"; }) //
      (build { target = "zc706"; variant = "acpki_nist_qc2_satellite_100mhz"; }) //
      (build { target = "kasli_soc"; variant = "demo"; json = ./demo.json; }) //
      (build { target = "kasli_soc"; variant = "master"; json = ./kasli-soc-master.json; }) //
      (build { target = "kasli_soc"; variant = "satellite"; json = ./kasli-soc-satellite.json; });

    hydraJobs = packages.x86_64-linux // { inherit zc706-hitl-tests; inherit gateware-sim; };

    devShell.x86_64-linux = pkgs.mkShell {
      name = "artiq-zynq-dev-shell";
      buildInputs = with pkgs; [
        rustPlatform.rust.rustc
        rustPlatform.rust.cargo
        llvmPackages_9.llvm
        llvmPackages_9.clang-unwrapped
        gnumake
        cacert
        zynqpkgs.cargo-xbuild
        zynqpkgs.mkbootimage
        openocd  
        openssh rsync
        (python3.withPackages(ps: (with artiqpkgs; [ migen migen-axi misoc artiq artiq-netboot ps.jsonschema ps.pyftdi ])))
        artiqpkgs.artiq
        artiqpkgs.vivado
        binutils-arm
      ];
      XARGO_RUST_SRC = "${rustPlatform.rust.rustc}/lib/rustlib/src/rust/library";
      CLANG_EXTRA_INCLUDE_DIR = "${pkgs.llvmPackages_9.clang-unwrapped.lib}/lib/clang/9.0.1/include";
      OPENOCD_ZYNQ = "${zynq-rs}/openocd";
      SZL = "${zynqpkgs.szl}";
    };

    makeArtiqZynqPackage = build;

  };
}