[Nix-dev] Switching the default kernel in configuration.nix

[Tony White]

I'd like to learn how to switch the default kernel from 2.6.25 please.
I've tried changing the option in configuration.nix but without
success. I think I'm missing something but can't see what.

Here's configuration.nix :

{pkgs, config, ...}:

{

 	time = {
    timeZone = "Europe/London";
    };

	boot = {

	grubDevice = [ "/dev/sdb1" ];

	extraKernelParams = [
	"vga=intelfb:1024x768-32 at 60"
	"mem=1024M" # The machine suffers from a memory allocation bug
	"lapic" ];

	resumeDevice = [ "13:19" ];

#        Device for manual resume attempt during boot. Looks like
#        major:minor. ls -l /dev/SWAP_PARTION shows them.

#    kernelPackages = [ pkgs.kernelPackages_2_6_28 ];

    configurationName = [ "NixOS" ];

	initrd = {

	extraKernelModules = [
	"ata_piix" "uhci_hcd" "ehci_hcd" "usb_storage" "acpi_cpufreq" "ext3"
	"intelfb" "asus_laptop" "shpchp" "pci_hotplug" "dm_mod" "jbd"
"ide_generic" "ide_disk"
	"ide_core" "sr_mod" "sd_mod" "scsi_wait_scan" "usbhid" "ohci_hcd"
	"usbcore" "scsi_transport_spi" "ahci" "libata" "scsi_mod" ];

	kernelModules = [];

	};
};

	fileSystems = [

	{ mountPoint = "/";
	device = "/dev/sdb1";
	label = "nixos";
	fsType = "ext3";
	options = "data=journal,noatime";
	}

	{ mountPoint = "/media/sda2";
	device = "/dev/sda2";
	fsType = "ext3";
	options = "noatime";
	}

	{ mountPoint = "/media/sda3";
	device = "/dev/sda3";
	label = "WORKAREA";
	fsType = "vfat";
	}

	{ mountPoint = "/media/sda4";
	device = "/dev/sda4";
	label = "WINDOWS";
	fsType = "vfat";
	} ];

	swapDevices = [
	{ label = "swap";
	device = "/dev/sda1";
	} ];

  nix = {
#       This option defines the maximum number of jobs that Nix will try
#        to build in parallel.  The default is 1.  You should generally
#        set it to the number of CPUs in your system (e.g., 2 on a Athlon
#        64 X2).
    maxJobs = 1;
  };

  networking = {
    hostName = "m3n";
  };

  services = {

    xserver = {
# This needs serious revision by me because there are so many options to set.
	enable = true;
	 autorun = true;
      exportConfiguration = true;
      videoDriver = "i810";
	resolutions = [{x = 1024; y = 768;} {x = 800; y = 600;} {x = 640; y = 480;}];
      driSupport = true;
      sessionType = "kde4";
      isClone = false;
      layout = "gb";
      xkbModel = "pc105";
      xkbOptions = "compose:rwin";
      synaptics = {
	enable = true;
	};

	    };

udev = {
      # Warning: setting this option requires acceptance of the firmware
      # license, see http://ipw2100.sourceforge.net/firmware.php?fid=4.
      addFirmware = [ pkgs.ipw2100fw ];
    };

};

#sudo = {
#	enable = true;
#	configFile = "
# WARNING: do not edit this file directly or with \"visudo\".  Instead,
# edit the source file in /etc/nixos/nixos/etc/sudoers.

# \"root\" is allowed to do anything.
#root        ALL=(ALL) SETENV: ALL

# Users in the \"wheel\" group can do anything.
#%wheel      ALL=(ALL) SETENV: ALL
#        ";
#      };

users = {

   extraUsers = [
	{ name = "tony";
          uid = 500;
          description = "Tony";
          home = "/home/tony";
          createHome = true;
          group = "tony";
          extraGroups = [ "users" "wheel" ];
          shell = "/bin/sh";
        }
      ];

    extraGroups = [
        { name = "tony";
          gid = 500;
        }
      ];

	};

  i18n = {
	defaultLocale = "en_GB.UTF-8";
#    consoleFont = "lat9w-16";
    consoleKeyMap = "uk";
	};

  powerManagement = {
	enable = true;
	};

}



I've hashed out the sudo section too because I can't seem to be able
to set that correctly either.
Any help would be greatly appreciated because I intend to compile
kernels quite frequently, So being able to switch between each one and
the default one would help a bit.

Many thanks,

Tony