make vm architecture agnostic

hardware/vm-generic/default.nix

@@ -0,0 +1,40 @@
+# Do not modify this file!  It was generated by ‘nixos-generate-config’
+# and may be overwritten by future invocations.  Please make changes
+# to /etc/nixos/configuration.nix instead.
+{
+  lib,
+  pkgs,
+  system,
+  ...
+}: {
+  imports = [];
+
+  boot.initrd.availableKernelModules = ["ehci_pci" "xhci_pci" "usbhid" "sr_mod"];
+  boot.initrd.kernelModules = [];
+  boot.kernelModules = [];
+  boot.extraModulePackages = [];
+
+  fileSystems."/" = {
+    device = "/dev/disk/by-label/nixos";
+    fsType = "ext4";
+  };
+
+  fileSystems."/boot" = {
+    device = "/dev/disk/by-label/boot";
+    fsType = "vfat";
+    options = ["fmask=0077" "dmask=0077"];
+  };
+
+  swapDevices = [
+    {device = "/dev/disk/by-label/swap";}
+  ];
+
+  # Set platform from the system argument passed by the flake
+  nixpkgs.hostPlatform = lib.mkDefault system;
+
+  # Enable Parallels tools only on aarch64
+  hardware.parallels.enable = lib.mkIf (system == "aarch64-linux") true;
+  nixpkgs.config.allowUnfreePredicate =
+    lib.mkIf (system == "aarch64-linux")
+    (pkg: builtins.elem (lib.getName pkg) ["prl-tools"]);
+}