Add support for fourmi display via custom DRM kernel driver flake

Signed-off-by: Mel <mel@rnrd.eu>

1 files changed, 32 insertions, 3 deletions

diff --git a/flake.nix b/flake.nix
index c52d5d8..ac30df6 100644
--- a/flake.nix
+++ b/flake.nix
@@ -39,6 +39,11 @@
       url = "github:NousResearch/hermes-agent";
       inputs.nixpkgs.follows = "nixpkgs-unstable";
     };
+
+    mhs35-drm = {
+      url = "git+https://git.rnrd.eu/mhs35-drm";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
   };
 
   outputs = inputs @ { self, nixpkgs, nixpkgs-unstable, home-manager, agenix, ... }:
@@ -77,7 +82,23 @@
 
     overlays = [ agenix.overlays.default ];
 
-    packageSetsForSystem = system: let
+    # per-machine overlays.
+    # as we only work with immutable package sets, we need to make sure
+    # all injected overlays are correct ourselves right here, which modules
+    # would mutate our package set to achieve automatically.
+    machineOverlays = {
+      fourmi = [
+        # `hardware.raspberry-pi."4".apply-overlays-dtmerge.enable`.
+        (final: prev: {
+          deviceTree = prev.deviceTree // {
+            applyOverlays = final.callPackage
+              "${inputs.nixos-hardware}/raspberry-pi/4/apply-overlays-dtmerge.nix" { };
+          };
+        })
+      ];
+    };
+
+    packageSetsWith = { system, overlays }: let
       pkgsInputs =
         i: { inherit system; config = import ./config.nix; } // i;
     in rec {
@@ -88,13 +109,21 @@
       auxiliaryPkgs = import ./pkgs (pkgsInputs { inherit pkgs unstablePkgs; });
     };
 
+    packageSetsForSystem = system:
+      packageSetsWith { inherit system overlays; };
+
+    packageSetsForMachine = machine: packageSetsWith {
+      inherit (machine) system;
+      overlays = overlays ++ (machineOverlays.${machine.name} or [ ]);
+    };
+
     inherit (nixpkgs) lib;
   in {
     nixosConfigurations = lib.mergeAttrsList (map (machine: {
       ${machine.name} = nixpkgs.lib.nixosSystem {
 
         specialArgs = inputs // {
-          inherit (packageSetsForSystem machine.system) unstablePkgs auxiliaryPkgs;
+          inherit (packageSetsForMachine machine) unstablePkgs auxiliaryPkgs;
           inherit machines;
           me = machine // { is = mkMachineIdentities machines machine; };
           keys = import ./secrets/keys.nix;
@@ -103,7 +132,7 @@
 
         modules = [
           nixpkgs.nixosModules.readOnlyPkgs
-          { nixpkgs.pkgs = (packageSetsForSystem machine.system).pkgs; }
+          { nixpkgs.pkgs = (packageSetsForMachine machine).pkgs; }
 
           ./machines/${machine.name}