add grub config

Former-commit-id: 2183824c34

nixos/grub.nix

@@ -0,0 +1,32 @@
+{ pkgs, ... }: {
+  boot = {
+    bootspec.enable = true;
+
+    loader = {
+      efi.canTouchEfiVariables = true;
+      grub = {
+        enable = true;
+        devices = [ "nodev" ];
+        efiSupport = true;
+        useOSProber = true;
+        gfxmodeEfi = "1280x720";
+      };
+    };
+
+    tmp.cleanOnBoot = true;
+    kernelPackages =
+      pkgs.linuxPackages_latest; # _zen, _hardened, _rt, _rt_latest, etc.
+
+    # Silent boot
+    kernelParams = [
+      "quiet"
+      "splash"
+      "vga=current"
+      "rd.systemd.show_status=false"
+      "rd.udev.log_level=3"
+      "udev.log_priority=3"
+    ];
+    consoleLogLevel = 0;
+    initrd.verbose = false;
+  };
+}