Update installer bootloader configuration

modules/installer/default.nix

@@ -21,7 +21,17 @@ in {
     (modulesPath + "/profiles/installation-device.nix")
   ];
 
-  # boot.loader.timeout = lib.mkForce 0;
+  boot = {
+    consoleLogLevel = 0;
+    kernelParams = ["quiet"];
+    initrd.verbose = false;
+    loader.systemd-boot.enable = true;
+    loader.timeout = lib.mkForce 0;
+    plymouth = {
+      enable = true;
+      theme = "breeze";
+    };
+  };
 
   # Adds terminus_font for people with HiDPI displays
   console.packages = options.console.packages.default ++ [pkgs.terminus_font];
@@ -32,12 +42,6 @@ in {
   # ISO naming.
   isoImage.isoName = "${config.isoImage.isoBaseName}-${config.system.nixos.label}-${pkgs.stdenv.hostPlatform.system}.iso";
 
-  # EFI booting
-  isoImage.makeEfiBootable = true;
-
-  # USB booting
-  isoImage.makeUsbBootable = true;
-
   # An installation media cannot tolerate a host config defined file
   # system layout on a fresh machine, before it has been formatted.
   swapDevices = mkImageMediaOverride [];
@@ -93,9 +97,6 @@ in {
   # which lags behind kernel releases, potentially causing broken builds.
   virtualisation.virtualbox.guest.enable = false;
 
-  # Enable plymouth
-  boot.plymouth.enable = true;
-
   environment.defaultPackages = with pkgs; [
     # Include gparted for partitioning disks.
     gparted

modules/installer/iso-image.nix

@@ -566,22 +566,6 @@ in {
       '';
     };
 
-    isoImage.makeEfiBootable = mkOption {
-      default = false;
-      type = lib.types.bool;
-      description = ''
-        Whether the ISO image should be an EFI-bootable volume.
-      '';
-    };
-
-    isoImage.makeUsbBootable = mkOption {
-      default = false;
-      type = lib.types.bool;
-      description = ''
-        Whether the ISO image should be bootable from CD as well as USB.
-      '';
-    };
-
     isoImage.efiSplashImage = mkOption {
       default = pkgs.fetchurl {
         url = "https://raw.githubusercontent.com/NixOS/nixos-artwork/a9e05d7deb38a8e005a2b52575a3f59a63a4dba0/bootloader/efi-background.png";
@@ -827,8 +811,6 @@ in {
           source = "${pkgs.syslinux}/share/syslinux";
           target = "/isolinux";
         }
-      ]
-      ++ optionals config.isoImage.makeEfiBootable [
         {
           source = efiImg;
           target = "/boot/efi.img";
@@ -872,14 +854,12 @@ in {
           else null;
         squashfsContents = config.isoImage.storeContents;
         squashfsCompression = config.isoImage.squashfsCompression;
-      }
-      // optionalAttrs (config.isoImage.makeUsbBootable && config.isoImage.makeBiosBootable) {
-        usbBootable = true;
-        isohybridMbrImage = "${pkgs.syslinux}/share/syslinux/isohdpfx.bin";
-      }
-      // optionalAttrs config.isoImage.makeEfiBootable {
         efiBootable = true;
         efiBootImage = "boot/efi.img";
+      }
+      // optionalAttrs (config.isoImage.makeBiosBootable) {
+        usbBootable = true;
+        isohybridMbrImage = "${pkgs.syslinux}/share/syslinux/isohdpfx.bin";
       });
 
     boot.postBootCommands = ''