Test 1 - EDID Spoofing for Android 4K

2026-08-25 21:40:56 -05:00
parent 87fca854f4
commit dfa7320a37
5 changed files with 226 additions and 2 deletions
@@ -0,0 +1,74 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.kioskEdid;
+
+  overrideModule = types.submodule {
+    options = {
+      connector = mkOption {
+        type = types.str;
+        example = "HDMI-A-1";
+        description = ''
+          DRM connector name to apply the EDID override to.
+          Check `ls /sys/class/drm/` on target hardware to confirm the
+          exact name (e.g. HDMI-A-1, HDMI-A-2).
+        '';
+      };
+
+      edidFile = mkOption {
+        type = types.path;
+        description = ''
+          Path to the binary EDID file to force for this connector.
+        '';
+      };
+
+      forceConnected = mkOption {
+        type = types.bool;
+        default = true;
+        description = ''
+          Also force this connector to be treated as connected
+          (video=<connector>:e), in case the real link reports
+          disconnected/garbled state through a splitter or wireless kit.
+        '';
+      };
+    };
+  };
+in
+{
+  options.services.kioskEdid = {
+    enable = mkEnableOption "forcing custom EDIDs on one or more display connectors";
+
+    overrides = mkOption {
+      type = types.listOf overrideModule;
+      default = [ ];
+      description = ''
+        List of per-connector EDID overrides to apply. Each entry gets its
+        own firmware file and its own drm.edid_firmware kernel param.
+      '';
+      example = literalExpression ''
+        [
+          { connector = "HDMI-A-1"; edidFile = ./android-4k30-edid.bin; }
+          { connector = "HDMI-A-2"; edidFile = ./android-4k30-edid.bin; }
+        ]
+      '';
+    };
+  };
+
+  config = mkIf cfg.enable {
+    hardware.firmware = map
+      (o: pkgs.runCommand "kiosk-edid-firmware-${o.connector}" { } ''
+        mkdir -p $out/lib/firmware/edid
+        cp ${o.edidFile} $out/lib/firmware/edid/${o.connector}.bin
+      '')
+      cfg.overrides;
+
+    boot.kernelParams = flatten (map
+      (o:
+        [ "drm.edid_firmware=${o.connector}:edid/${o.connector}.bin" ]
+        ++ optional o.forceConnected "video=${o.connector}:e"
+      )
+      cfg.overrides);
+  };
+}