use extlinux

hardware-configuration.nix

@@ -8,8 +8,7 @@
 
   boot = {
     tmp.cleanOnBoot = true;
-    kernelModules = [ "cma=256M" ];
-    extraModulePackages = [ ];
+    kernelPackages = pkgs.linuxPackages_rpi;
 
     loader = {
       grub = {
@@ -17,20 +16,12 @@
         enable = false;
       };
 
-      raspberryPi = {
-        enable = true;
-        version = 3;
-        firmwareConfig = ''
-          gpu_mem=256
-        '';
-
-        uboot = {
+      generic-extlinux-compatible = {
         enable = true;
         configurationLimit = 10;
       };
     };
   };
-  };
 
   fileSystems."/" = {
     device = "/dev/disk/by-uuid/44444444-4444-4444-8888-888888888888";
@@ -57,6 +48,7 @@
   swapDevices = [
     {
       device = "/swapfile";
+      size = 1024;
     }
   ];