Fix description of boot.consoleLogLevel

nixos/modules/installer/cd-dvd/iso-image.nix

@@ -218,6 +218,8 @@ in
     system.boot.loader.kernelFile = "bzImage";
     environment.systemPackages = [ pkgs.grub2 pkgs.grub2_efi pkgs.syslinux ];
 
+    boot.consoleLogLevel = 7;
+
     # In stage 1 of the boot, mount the CD as the root FS by label so
     # that we don't need to know its device.  We pass the label of the
     # root filesystem on the kernel command line, rather than in
@@ -229,6 +231,8 @@ in
     boot.kernelParams =
       [ "root=LABEL=${config.isoImage.volumeID}"
         "boot.shell_on_fail"
+        "nomodeset"
+        "systemd.log_level=debug"
       ];
 
     fileSystems."/" =

nixos/modules/system/boot/kernel.nix

@@ -49,9 +49,8 @@ in
       type = types.int;
       default = 4;
       description = ''
-        The kernel console log level.  Only log messages with a
-        priority numerically less than this will appear on the
-        console.
+        The kernel console log level.  Log messages with a priority
+        numerically less than this will not appear on the console.
       '';
     };