{ platform ? __currentSystem
, relName ?
    if builtins.pathExists ../../relname
    then builtins.readFile ../../relname
    else "nixos-${builtins.readFile ../../VERSION}"
, compressImage ? false
, nixpkgs ? ../../../nixpkgs
, services ? ../../../services
# This option allows easy building of Rescue CD with 
# modified package set / driver set / anything.
# For easier maitenance, let overrider know the current
# options
, configurationOverrides ? (config: {})
# Whether to put all the build-time dependencies on DVD
, includeBuildDeps ? false
, includeTarballs ? true
}:

rec {


  cdLabel = "NIXOS_INSTALLATION_CD";

  
  baseConfiguration = {
  
    boot = {
      isLiveCD = true;
      extraTTYs = [7 8]; # manual, rogue
      extraModulePackages = [system.kernelPackages.aufs];
      
      kernelPackages = pkgs.kernelPackages_2_6_28;
      
      initrd = {
        extraKernelModules = [
          # The initrd should contain any modules necessary for
          # mounting the CD.
        
          # SATA/PATA support.
          "ahci"

          "ata_piix"
          
          "sata_inic162x" "sata_nv" "sata_promise" "sata_qstor"
          "sata_sil" "sata_sil24" "sata_sis" "sata_svw" "sata_sx4"
          "sata_uli" "sata_via" "sata_vsc"

          "pata_ali" "pata_amd" "pata_artop" "pata_atiixp"
          "pata_cs5520" "pata_cs5530" /* "pata_cs5535" */ "pata_efar"
          "pata_hpt366" "pata_hpt37x" "pata_hpt3x2n" "pata_hpt3x3"
          "pata_it8213" "pata_it821x" "pata_jmicron" "pata_marvell"
          "pata_mpiix" "pata_netcell" "pata_ns87410" "pata_oldpiix"
          "pata_pcmcia" "pata_pdc2027x" /* "pata_qdi" */ "pata_rz1000"
          "pata_sc1200" "pata_serverworks" "pata_sil680" "pata_sis"
          "pata_sl82c105" "pata_triflex" "pata_via"
          # "pata_winbond" <-- causes timeouts in sd_mod

          # SCSI support (incomplete).
          "3w-9xxx" "3w-xxxx" "aic79xx" "aic7xxx" "arcmsr" 
        
          # USB support, especially for booting from USB CD-ROM
          # drives.  Also include USB keyboard support for when
          # something goes wrong in stage 1.
          "ehci_hcd"
          "ohci_hcd"
          "uhci_hcd"
          "usbhid"
          "usb_storage"

          # Firewire support.  Not tested.
          "ohci1394" "sbp2"

          # Virtio (QEMU, KVM etc.) support.
          "virtio_net" "virtio_pci" "virtio_blk" "virtio_balloon"

          # Wait for SCSI devices to appear.
          "scsi_wait_scan"

          # Needed for live-CD operation.
          "aufs"
        ];
      };
    };

    fileSystems = [
      { mountPoint = "/";
        label = cdLabel;
      }
    ];

    networking = {
      enableIntel3945ABGFirmware = true;
    };
    
    services = {
    
      sshd = {
        enable = false;
        forwardX11 = false;
      };
      
      xserver = {
        enable = false;
      };

      showManual = {
        enable = true;
	manualFile = manual;
      };

      rogue = {
        enable = true;
      };

      extraJobs = [
        # Unpack the NixOS/Nixpkgs sources to /etc/nixos.
        # !!! run this synchronously
        { name = "unpack-sources";
          job = "
            start on startup
            script
              export PATH=${pkgs.gnutar}/bin:${pkgs.bzip2}/bin:$PATH

              mkdir -p /mnt

              ${system.nix}/bin/nix-store --load-db < /nix-path-registration

              mkdir -p /etc/nixos/nixos
              tar xjf /install/nixos.tar.bz2 -C /etc/nixos/nixos
              mkdir -p /etc/nixos/nixpkgs
              tar xjf /install/nixpkgs.tar.bz2 -C /etc/nixos/nixpkgs
              mkdir -p /etc/nixos/services
              tar xjf /install/services.tar.bz2 -C /etc/nixos/services
              chown -R root.root /etc/nixos
            end script
          ";
        }
      
      ];

      mingetty = {
        helpLine = ''
        
          Log in as "root" with an empty password.  Press <Alt-F7> for help.
        '';
      };
      
    };

    fonts = {
      enableFontConfig = false;
    };
    
    installer = {
      nixpkgsURL = http://nixos.org/releases/nixpkgs/unstable;
    };

    security = {
      sudo = {
        enable = false;
      };
    };
 
    environment = {
      extraPackages = [
        pkgs.subversion # for nixos-checkout
        pkgs.w3m # needed for the manual anyway
        pkgs.testdisk # useful for repairing boot problems
        pkgs.mssys # for writing Microsoft boot sectors / MBRs
        pkgs.ntfsprogs # for resizing NTFS partitions
        pkgs.parted
        pkgs.sshfsFuse
      ];
    };
   
  };

  configuration = baseConfiguration // (configurationOverrides baseConfiguration);

  system = import ../../system/system.nix {
    inherit configuration platform nixpkgs;
  };

  pkgs = system.pkgs;


  # The NixOS manual, with a backward compatibility hack for Nix <=
  # 0.11 (you won't get the manual).
  manual =
    if builtins ? unsafeDiscardStringContext
    then "${import ../../doc/manual {inherit nixpkgs;}}/manual.html"
    else pkgs.writeText "dummy-manual" "Manual not included in this build!";


  # We need a copy of the Nix expressions for Nixpkgs and NixOS on the
  # CD.  We put them in a tarball because accessing that many small
  # files from a slow device like a CD-ROM takes too long.
  makeTarball = tarName: input: pkgs.runCommand "tarball" {inherit tarName;} "
    ensureDir $out
    (cd ${input} && tar cvfj $out/${tarName} . \\
      --exclude '*~' --exclude 'result')
  ";

  
  # Put the current directory in a tarball.
  nixosTarball = makeTarball "nixos.tar.bz2" ../..;


  # Put Services in a tarball.
  servicesTarball = makeTarball "services.tar.bz2" services;


  # Put Nixpkgs in a tarball.
  nixpkgsTarball = makeTarball "nixpkgs.tar.bz2" nixpkgs;


  # The configuration file for Grub.
  grubCfg = pkgs.writeText "menu.lst" (''
    default 0
    timeout 10
    splashimage /boot/background.xpm.gz

    title Boot from hard disk
      root (hd0)
      chainloader +1
    
    title NixOS Installer / Rescue
      kernel /boot/vmlinuz init=/init ${toString system.config.boot.kernelParams}
      initrd /boot/initrd

    title Memtest86+
      kernel /boot/memtest.bin
  '' 
    + (pkgs.lib.concatStringsSep "\n\n" 
        (map (x: ''
	  title NixOS: ${x.configurationName}
	    kernel ${x.kernel} systemConfig=${x} init=${x.bootStage2} ${toString system.config.boot.kernelParams}
	    initrd ${x.initrd}
	'') system.children)))
    ;


  # Create an ISO image containing the Grub boot loader, the kernel,
  # the initrd produced above, and the closure of the stage 2 init.
  rescueCD = import ../../helpers/make-iso9660-image.nix {
    inherit nixpkgs;
    inherit (pkgs) stdenv perl cdrkit;
    isoName = "${relName}-${platform}.iso";

    # Single files to be copied to fixed locations on the CD.
    contents = [
      { source = "${pkgs.grub}/lib/grub/${if platform == "i686-linux" then "i386-pc" else "x86_64-unknown"}/stage2_eltorito";
        target = "boot/grub/stage2_eltorito";
      }
      { source = grubCfg;
        target = "boot/grub/menu.lst";
      }
      { source = system.kernel + "/vmlinuz";
        target = "boot/vmlinuz";
      }
      { source = system.initialRamdisk + "/initrd";
        target = "boot/initrd";
      }
      { source = pkgs.memtest86 + "/memtest.bin";
        target = "boot/memtest.bin";
      }
      { source = system.config.boot.grubSplashImage;
        target = "boot/background.xpm.gz";
      }
    ]
    ++
    pkgs.lib.optionals includeTarballs [
      { source = nixosTarball + "/" + nixosTarball.tarName;
        target = "/install/" + nixosTarball.tarName;
      }
      { source = nixpkgsTarball + "/nixpkgs.tar.bz2";
        target = "/install/nixpkgs.tar.bz2";
      }
      { source = servicesTarball + "/services.tar.bz2";
        target = "/install/services.tar.bz2";
      }
    ];

    # Closures to be copied to the Nix store on the CD.
    storeContents = [
      { object = system.bootStage2;
        symlink = "/init";
      }
      { object = system.system;
        symlink = "/system";
      }
      # To speed up the installation, provide the full stdenv.
      { object = pkgs.stdenv;
        symlink = "none";
      }
    ]
      ++ pkgs.lib.optional includeBuildDeps {
          object = system.system.drvPath;
          symlink = "none";
        }
      ;
    
    bootable = true;
    bootImage = "boot/grub/stage2_eltorito";

    inherit compressImage;

    volumeID = cdLabel;
  };
}