init aarch64 support

devices/r2s/default.nix

@@ -0,0 +1,23 @@
+inputs:
+{
+  config =
+  {
+    nixos =
+    {
+      model.arch = "aarch64";
+      system =
+      {
+        fileSystems =
+        {
+          mount.btrfs."/dev/disk/by-partlabel/r2s-root" = { "/nix" = "/nix"; "/nix/rootfs/current" = "/"; };
+          swap = [ "/nix/swap/swap" ];
+        };
+        network = {};
+      };
+      services =
+      {
+        sshd = {};
+      };
+    };
+  };
+}

flake/lib/buildNixpkgsConfig/default.nix

@@ -1,12 +1,12 @@
-# inputs = { lib, topInputs, ...}; nixpkgs = { march, cuda, nixRoot, nixos };
+# inputs = { lib, topInputs, ...}; nixpkgs = { march, cuda, nixRoot, nixos, arch };
 { inputs, nixpkgs }:
 let
   platformConfig =
-    if nixpkgs.march == null then { system = "x86_64-linux"; }
+    if nixpkgs.march == null then { system = "${nixpkgs.arch or "x86_64"}-linux"; }
     else
     {
       ${if nixpkgs.nixos then "hostPlatform" else "localSystem"} =
-        { system = "x86_64-linux"; gcc = { arch = nixpkgs.march; tune = nixpkgs.march; }; };
+        { system = "${nixpkgs.arch or "x86_64"}-linux"; gcc = { arch = nixpkgs.march; tune = nixpkgs.march; }; };
     };
   cudaConfig = inputs.lib.optionalAttrs (nixpkgs.cuda != null)
   (

flake/nixos.nix

@@ -2,7 +2,6 @@
 let
   singles = [ "nas" "pc" "vps4" "vps6" "one" "srv3" ];
   cluster = { srv1 = 3; srv2 = 2; };
-  arch.r2s = "aarch64";
   deviceModules = builtins.listToAttrs
   (
     (builtins.map
@@ -28,7 +27,7 @@ let
 in builtins.mapAttrs
   (n: v: inputs.nixpkgs.lib.nixosSystem
   {
-    system = "${arch.${n} or "x86_64"}-linux";
+    system = null;
     specialArgs = { topInputs = inputs; inherit localLib; };
     modules = localLib.mkModules v;
   })

modules/model.nix

@@ -3,6 +3,7 @@ inputs:
   options.nixos.model = let inherit (inputs.lib) mkOption types; in
   {
     hostname = mkOption { type = types.nonEmptyStr; };
+    arch = mkOption { type = types.nonEmptyStr; default = "x86_64"; };
     type = mkOption { type = types.enum [ "minimal" "desktop" "server" ]; default = "minimal"; };
     private = mkOption { type = types.bool; default = false; };
     cluster = mkOption

modules/system/nixpkgs.nix

@@ -16,7 +16,10 @@ inputs:
   config = let inherit (inputs.config.nixos.system) nixpkgs; in
   {
     nixpkgs = inputs.localLib.buildNixpkgsConfig
-      { inherit inputs; nixpkgs = nixpkgs // { nixRoot = null; nixos = true; }; };
+    {
+      inherit inputs;
+      nixpkgs = nixpkgs // { nixRoot = null; nixos = true; inherit (inputs.config.nixos.model) arch; };
+    };
     boot.kernelPatches = inputs.lib.mkIf (nixpkgs.march != null)
     [{
       name = "native kernel";