From b4b0598879d937f291af5681c1a0a0e719808d0e Mon Sep 17 00:00:00 2001
From: Lan Tian <xuyh0120@outlook.com>
Date: Mon, 8 Dec 2025 19:46:57 -0800
Subject: [PATCH] Add overlay and example NixOS configuration

---
 README.md | 21 ++++++++++++++++++---
 flake.nix | 50 ++++++++++++++++++++++++++++++++++++++++++++++----
 2 files changed, 64 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index 575f895..63076f8 100644
--- a/README.md
+++ b/README.md
@@ -41,11 +41,26 @@ Add this repo to the inputs section of your `flake.nix`:
 }
 ```
 
-And then specify `inputs.nix-cachyos-kernel.legacyPackages.${pkgs.system}.linuxPackages-cachyos-latest` (or other variants you'd like) in your `boot.kernelPackages` option:
+Add the repo's overlay in your NixOS configuration, this will expose the packages in this flake as `pkgs.cachyosKernels.*`.
+
+Then specify `pkgs.cachyosKernels.linuxPackages-cachyos-latest` (or other variants you'd like) in your `boot.kernelPackages` option.
+
+### Example configuration
 
 ```nix
-{ pkgs, inputs, ... }:
 {
-  boot.kernelPackages = inputs.nix-cachyos-kernel.legacyPackages.${pkgs.system}.linuxPackages-cachyos-latest
+  nixosConfigurations.example = inputs.nixpkgs.lib.nixosSystem {
+    system = "x86_64-linux";
+    modules = [
+      (
+        { pkgs, ... }:
+        {
+          nixpkgs.overlays = [ self.overlay ];
+          boot.kernelPackages = pkgs.cachyosKernels.linuxPackages-cachyos-latest;
+          # ... your other configs
+        }
+      )
+    ];
+  };
 }
 ```
diff --git a/flake.nix b/flake.nix
index 01687ac..1798496 100644
--- a/flake.nix
+++ b/flake.nix
@@ -20,7 +20,19 @@
         lib,
         ...
       }:
-      {
+      let
+        loadPackages =
+          pkgs:
+          lib.removeAttrs
+            (pkgs.callPackage ./kernel-cachyos {
+              inherit inputs;
+            })
+            [
+              "override"
+              "overrideDerivation"
+            ];
+      in
+      rec {
         systems = [
           "x86_64-linux"
           "aarch64-linux"
@@ -33,12 +45,42 @@
           }:
           rec {
             # Legacy packages contain linux-cachyos-* and linuxPackages-cachyos-*
-            legacyPackages = pkgs.callPackage ./kernel-cachyos {
-              inherit inputs;
-            };
+            legacyPackages = loadPackages pkgs;
+
             # Packages only contain linux-cachyos-* due to Flake schema requirements
             packages = lib.filterAttrs (_: lib.isDerivation) legacyPackages;
           };
+
+        flake = {
+          overlay = self.overlays.default;
+          overlays.default = final: prev: {
+            cachyosKernels = loadPackages prev;
+          };
+
+          nixosConfigurations = lib.genAttrs systems (
+            system:
+            inputs.nixpkgs.lib.nixosSystem {
+              inherit system;
+              modules = [
+                (
+                  { pkgs, ... }:
+                  {
+                    nixpkgs.overlays = [ self.overlay ];
+                    boot.kernelPackages = pkgs.cachyosKernels.linuxPackages-cachyos-latest;
+
+                    # Minimal config to make test configuration build
+                    boot.loader.grub.devices = [ "/dev/vda" ];
+                    fileSystems."/" = {
+                      device = "tmpfs";
+                      fsType = "tmpfs";
+                    };
+                    system.stateVersion = lib.trivial.release;
+                  }
+                )
+              ];
+            }
+          );
+        };
       }
     );
 }