diff --git a/flake.nix b/flake.nix
index 1c22674d..d9d9e9da 100644
--- a/flake.nix
+++ b/flake.nix
@@ -25,14 +25,16 @@
       patches = import ./nixpatches/list.nix nixpkgs.legacyPackages.${system}.fetchpatch;
     };
     # return something which behaves like `pkgs`, for the provided system
-    nixpkgsFor = system: import (patchedPkgs system) { inherit system; };
+    # `local` = architecture of builder. `target` = architecture of the system beying deployed to
+    nixpkgsFor = local: target: import (patchedPkgs target) { crossSystem = target; localSystem = local; };
     # evaluate ONLY our overlay, for the provided system
-    customPackagesFor = system: import ./pkgs/overlay.nix (nixpkgsFor system) (nixpkgsFor system);
-    decl-machine = { name, system }:
+    customPackagesFor = local: target: import ./pkgs/overlay.nix (nixpkgsFor local target) (nixpkgsFor local target);
+    decl-machine = { name, local, target }:
     let
-      nixosSystem = import ((patchedPkgs system) + "/nixos/lib/eval-config.nix");
+      nixosSystem = import ((patchedPkgs target) + "/nixos/lib/eval-config.nix");
     in (nixosSystem {
-      inherit system;
+      # by default the local system is the same as the target, employing emulation when they differ
+      system = target;
       specialArgs = { inherit nixpkgs mobile-nixos home-manager impermanence; };
       modules = [
         ./modules
@@ -46,13 +48,19 @@
           nixpkgs.overlays = [
             (import "${mobile-nixos}/overlay/overlay.nix")
             (import ./pkgs/overlay.nix)
+            (next: prev: {
+              # non-emulated packages build *from* local *for* target.
+              # for large packages like the linux kernel which are expensive to build under emulation,
+              # the config can explicitly pull such packages from `pkgs.cross` to do more efficient cross-compilation.
+              cross = (nixpkgsFor local target) // (customPackagesFor local target);
+            })
           ];
         }
       ];
     });
 
-    decl-bootable-machine = { name, system }: rec {
-      nixosConfiguration = decl-machine { inherit name system; };
+    decl-bootable-machine = { name, local, target }: rec {
+      nixosConfiguration = decl-machine { inherit name local target; };
       # this produces a EFI-bootable .img file (GPT with a /boot partition and a system (/ or /nix) partition).
       # after building this:
       #   - flash it to a bootable medium (SD card, flash drive, HDD)
@@ -68,16 +76,21 @@
       #   - `nixos-rebuild --flake './#<machine>' switch`
       img = nixosConfiguration.config.system.build.img;
     };
-    machines.servo = decl-bootable-machine { name = "servo"; system = "aarch64-linux"; };
-    machines.desko = decl-bootable-machine { name = "desko"; system = "x86_64-linux"; };
-    machines.lappy = decl-bootable-machine { name = "lappy"; system = "x86_64-linux"; };
-    machines.moby = decl-bootable-machine { name = "moby"; system = "aarch64-linux"; };
-    machines.rescue = decl-bootable-machine { name = "rescue"; system = "x86_64-linux"; };
+    machines.servo = decl-bootable-machine { name = "servo"; local = "aarch64-linux"; target = "aarch64-linux"; };
+    machines.desko = decl-bootable-machine { name = "desko"; local = "x86_64-linux"; target = "x86_64-linux"; };
+    machines.lappy = decl-bootable-machine { name = "lappy"; local = "x86_64-linux"; target = "x86_64-linux"; };
+    machines.moby = decl-bootable-machine { name = "moby"; local = "aarch64-linux"; target = "aarch64-linux"; };
+    # special cross-compiled variant, to speed up deploys from an x86 box to the arm target
+    # note that these *do* produce different store paths, because the closure for the tools used to cross compile
+    # v.s. emulate differ.
+    # so deploying moby-cross and then moby incurs some rebuilding.
+    machines.moby-cross = decl-bootable-machine { name = "moby"; local = "x86_64-linux"; target = "aarch64-linux"; };
+    machines.rescue = decl-bootable-machine { name = "rescue"; local = "x86_64-linux"; target = "x86_64-linux"; };
   in {
     nixosConfigurations = builtins.mapAttrs (name: value: value.nixosConfiguration) machines;
     imgs = builtins.mapAttrs (name: value: value.img) machines;
-    packages.x86_64-linux = customPackagesFor "x86_64-linux";
-    packages.aarch64-linux = customPackagesFor "aarch64-linux";
+    packages.x86_64-linux = customPackagesFor "x86_64-linux" "x86_64-linux";
+    packages.aarch64-linux = customPackagesFor "aarch64-linux" "aarch64-linux";
   };
 }
 
diff --git a/machines/moby/default.nix b/machines/moby/default.nix
index f4352a5f..de9b12dd 100644
--- a/machines/moby/default.nix
+++ b/machines/moby/default.nix
@@ -8,13 +8,6 @@
     ./fs.nix
     ./kernel.nix
   ];
-  # nixpkgs.overlays = [(next: prev: {
-  #   # without this, kernel module build fails due to lacking dm_mod.
-  #   # see: https://github.com/NixOS/nixpkgs/issues/126755#issuecomment-869149243
-  #   # dm_mod appears to still be loaded, though? maybe some weird thing between compiled and dynamically-loaded mods?
-  #   makeModulesClosure = x:
-  #     prev.makeModulesClosure (x // { allowMissing = true; });
-  # })];
   # XXX colin: phosh doesn't work well with passwordless login
   users.users.colin.initialPassword = "147147";
   services.getty.autologinUser = "root";  # allows for emergency maintenance?
diff --git a/machines/moby/kernel.nix b/machines/moby/kernel.nix
index 5e34e0b8..f536ba14 100644
--- a/machines/moby/kernel.nix
+++ b/machines/moby/kernel.nix
@@ -114,27 +114,7 @@ in
   # - phone rotation sensor is off by 90 degrees
   # - ambient light sensor causes screen brightness to be shakey
   # - phosh greeter may not appear after wake from sleep
-  # TODO: if i plumbed a nixpkgs cross with my overlay here,
-  #   i could use `pkgs.linuxPackagesFor pkgs.linux-megous` instead.
-  boot.kernelPackages = let
-    nixpkgsCross = (import nixpkgs { localSystem = "x86_64-linux"; });
-    linux_5_18 = nixpkgsCross.pkgsCross.aarch64-multiplatform.linux_5_18;
-  in
-    pkgs.linuxPackagesFor (linux_5_18.override {
-      argsOverride = rec {
-        src = pkgs.fetchFromGitHub {
-          owner = "megous";
-          repo = "linux";
-          # branch: orange-pi-5.18
-          rev = "3ef835b665191e4833ae1363245be48e96013df6";
-          sha256 = "sha256-nQsBXeGLZhpem1p7Vnc8z7XB354AO1mn7VTj/hH5twY=";
-        };
-        version = "5.18.14";
-        modDirVersion = "5.18.14";
-      };
-    });
-  # non-cross compiled equivalent.
-  # boot.kernelPackages = pkgs.linuxPackagesFor pkgs.linux-megous;
+  boot.kernelPackages = pkgs.linuxPackagesFor pkgs.cross.linux-megous;
 
   boot.kernelPatches = [
     (patchDefconfig (kernelConfig //
@@ -149,7 +129,7 @@ in
     ))
   ];
 
-  # use nixos' kernel and add the stuff we want:
+  # alternatively, use nixos' kernel and add the stuff we want:
   # # cross-compilation optimization:
   # boot.kernelPackages =
   #   let p = (import nixpkgs { localSystem = "x86_64-linux"; });