Fiiiine, I'll just use a local fuckin file.

lib/types/host.nix

@@ -177,35 +177,37 @@ rec {
 
       android-dev = mkEnableOption "Enable ADB on the host.";
 
-      # FIXME: This probably belongs elsewhere...
-      initrd-ip = mkOption {
-        type = nullOr str;
-        description = "IP to assign to the kernel/initrd, to allow access when boot fails.";
-        default = null;
-      };
-
-      initrd-ssh-keypair = let
-        keypair = { ... }: {
+      initrd-network = let
+        keypair-type = { ... }: {
           options = {
             public-key = mkOption {
               type = str;
               description = "SSH public key.";
             };
 
-            private-key = mkOption {
+            private-key-file = mkOption {
               type = str;
-              description = "SSH private key.";
-            };
-
-            type = mkOption {
-              type = enum [ "rsa" "ecdsa" "ed25519" ];
-              description = "SSH key type.";
+              description = "Path to SSH private key (on the local host!).";
             };
           };
         };
+
+        initrd-network-config = { ... }: {
+          options = {
+            ip = mkOption {
+              type = str;
+              description = "IP to assign to the initrd image, allowing access to host during bootup.";
+            };
+            keypair = mkOption {
+              type = keypair-type;
+              description = "SSH host key pair to use for initrd.";
+            };
+          };
+        };
+
       in mkOption {
-        type = nullOr (submodule keypair);
-        description = "SSH Keypair to use for initrd.";
+        type = nullOr (submodule initrd-network-config);
+        description = "Configuration parameters to set up initrd SSH network.";
         default = null;
       };
     };