greatfet_firmware: include fw from official pypi

Include the latest cross-compiled firmware to match the host SW version.
This allows to use the standard `greatfet_firmware --autoflash` command
to perform the update. In addition it adds the DFU package for recovery
of a corrupt system.

Signed-off-by: Brian McGillion <bmg.avoin@gmail.com>

pkgs/development/python-modules/greatfet/default.nix

@@ -2,6 +2,7 @@
   buildPythonPackage,
   cmsis-svd,
   fetchFromGitHub,
+  fetchPypi,
   ipython,
   lib,
   prompt-toolkit,
@@ -11,6 +12,7 @@
   setuptools,
   tabulate,
   tqdm,
+  unzip,
 }:
 
 buildPythonPackage rec {
@@ -25,12 +27,36 @@ buildPythonPackage rec {
     hash = "sha256-qXPNatakMVtvl26FG1bx+ngCeqRpg1So6qFamKK8WWk=";
   };
 
+  # The prebuilt LPC firmware image (greatfet_usb.bin) and the DFU recovery
+  # stub (flash_stub.bin) are release artifacts cross-compiled from firmware/.
+  # They are absent from the git checkout (their build inputs are now-empty
+  # submodules) but are shipped in the upstream wheel. Without them
+  # `greatfet_firmware --autoflash` and DFU-mode firmware recovery are
+  # unavailable, so vendor them from the wheel to match `pip install greatfet`.
+  firmwareAssets = fetchPypi {
+    inherit pname version;
+    format = "wheel";
+    dist = "py3";
+    python = "py3";
+    hash = "sha256-sH1FAkfdC0HxRLZjfx7b2AYWMh4rtSijFgsU/YnVKq0=";
+  };
+
   sourceRoot = "${src.name}/host";
 
+  nativeBuildInputs = [ unzip ];
+
   postPatch = ''
     substituteInPlace pyproject.toml \
       --replace-fail ', "setuptools-git-versioning<2"' "" \
       --replace-fail 'dynamic = ["version"]' 'version = "${version}"'
+
+    # Restore the prebuilt firmware images shipped in the upstream wheel; the
+    # existing MANIFEST.in (recursive-include greatfet/assets *) then packages
+    # them into greatfet/assets/ where find_greatfet_asset() looks at runtime.
+    unzip -j -o ${firmwareAssets} \
+      'greatfet/assets/greatfet_usb.bin' \
+      'greatfet/assets/flash_stub.bin' \
+      -d greatfet/assets/
   '';
 
   build-system = [ setuptools ];