nixos/systemd-stage-1: Remove unnecessary binaries

We can make the growfs and makefs binaries conditional because we know
if we'll need them. Also move the cryptsetup generator to the luksroot
so it's not included when not needed.

We drop some generators altogether: systemd-getty-generator because we
don't have getty anyway in stage 1, systemd-system-update-generator
because we don't use that logic in NixOS and
systemd-veritysetup-generator because stage 1 has no veritysetup support
(yet) and if it had, we still wouldn't want to include the generator
unconditionally.

nixos/modules/system/boot/luksroot.nix

@@ -992,6 +992,7 @@ in
       ];
       storePaths = [
         "${config.boot.initrd.systemd.package}/lib/systemd/systemd-cryptsetup"
+        "${config.boot.initrd.systemd.package}/lib/systemd/system-generators/systemd-cryptsetup-generator"
       ];
 
     };

nixos/modules/system/boot/systemd/initrd.nix

@@ -105,6 +105,9 @@ let
         opts = options ++ optional autoFormat "x-systemd.makefs" ++ optional autoResize "x-systemd.growfs";
       in "${device} /sysroot${mountPoint} ${fsType} ${lib.concatStringsSep "," opts}") fileSystems);
 
+  needMakefs = lib.any (fs: fs.autoFormat) fileSystems;
+  needGrowfs = lib.any (fs: fs.autoResize) fileSystems;
+
   kernel-name = config.boot.kernelPackages.kernel.name or "kernel";
   modulesTree = config.system.modulesTree.override { name = kernel-name + "-modules"; };
   firmware = config.hardware.firmware;
@@ -360,18 +363,22 @@ in {
       storePaths = [
         # systemd tooling
         "${cfg.package}/lib/systemd/systemd-fsck"
-        "${cfg.package}/lib/systemd/systemd-growfs"
+        (lib.mkIf needGrowfs "${cfg.package}/lib/systemd/systemd-growfs")
         "${cfg.package}/lib/systemd/systemd-hibernate-resume"
         "${cfg.package}/lib/systemd/systemd-journald"
-        "${cfg.package}/lib/systemd/systemd-makefs"
+        (lib.mkIf needMakefs "${cfg.package}/lib/systemd/systemd-makefs")
         "${cfg.package}/lib/systemd/systemd-modules-load"
         "${cfg.package}/lib/systemd/systemd-remount-fs"
         "${cfg.package}/lib/systemd/systemd-shutdown"
         "${cfg.package}/lib/systemd/systemd-sulogin-shell"
         "${cfg.package}/lib/systemd/systemd-sysctl"
 
-        # additional systemd directories
-        "${cfg.package}/lib/systemd/system-generators"
+        # generators
+        "${cfg.package}/lib/systemd/system-generators/systemd-debug-generator"
+        "${cfg.package}/lib/systemd/system-generators/systemd-fstab-generator"
+        "${cfg.package}/lib/systemd/system-generators/systemd-gpt-auto-generator"
+        "${cfg.package}/lib/systemd/system-generators/systemd-hibernate-resume-generator"
+        "${cfg.package}/lib/systemd/system-generators/systemd-run-generator"
 
         # utilities needed by systemd
         "${cfg.package.util-linux}/bin/mount"
@@ -409,8 +416,8 @@ in {
         mkdir -p $out/etc/systemd/system
         touch $out/etc/systemd/system/systemd-{makefs,growfs}@.service
       '')];
-      services."systemd-makefs@".unitConfig.IgnoreOnIsolate = true;
-      services."systemd-growfs@".unitConfig.IgnoreOnIsolate = true;
+      services."systemd-makefs@" = lib.mkIf needMakefs { unitConfig.IgnoreOnIsolate = true; };
+      services."systemd-growfs@" = lib.mkIf needGrowfs { unitConfig.IgnoreOnIsolate = true; };
 
       services.initrd-nixos-activation = {
         after = [ "initrd-fs.target" ];