nixpkgs/modules/installer/cd-dvd/installation-cd-base.nix
2013-03-02 20:06:02 +01:00

67 lines
2.2 KiB
Nix

# This module contains the basic configuration for building a NixOS
# installation CD.
{ config, pkgs, ... }:
with pkgs.lib;
let
# We need a copy of the Nix expressions for Nixpkgs and NixOS on the
# CD. These are installed into the "nixos" channel of the root
# user, as expected by nixos-rebuild/nixos-install.
channelSources = pkgs.runCommand "nixos-${config.system.nixosVersion}"
{ expr = builtins.readFile ../../../lib/channel-expr.nix; }
''
mkdir -p $out/nixos
cp -prd ${cleanSource ../../..} $out/nixos/nixos
cp -prd ${cleanSource <nixpkgs>} $out/nixos/nixpkgs
chmod -R u+w $out/nixos/nixos
echo -n ${config.system.nixosVersion} > $out/nixos/nixos/.version
echo -n "" > $out/nixos/nixos/.version-suffix
echo "$expr" > $out/nixos/default.nix
'';
includeSources = true;
in
{
require =
[ ./memtest.nix
./iso-image.nix
# Profiles of this basic installation CD.
../../profiles/all-hardware.nix
../../profiles/base.nix
../../profiles/installation-device.nix
];
# ISO naming.
isoImage.isoName = "${config.isoImage.isoBaseName}-${config.system.nixosVersion}-${pkgs.stdenv.system}.iso";
isoImage.volumeID = "NIXOS_${config.system.nixosVersion}";
# Provide the NixOS/Nixpkgs sources in /etc/nixos. This is required
# for nixos-install.
boot.postBootCommands = optionalString includeSources
''
echo "unpacking the NixOS/Nixpkgs sources..."
mkdir -p /nix/var/nix/profiles/per-user/root
${config.environment.nix}/bin/nix-env -p /nix/var/nix/profiles/per-user/root/channels -i ${channelSources} --quiet
mkdir -m 0700 -p /root/.nix-defexpr
ln -s /nix/var/nix/profiles/per-user/root/channels /root/.nix-defexpr/channels
'';
# Make the installer more likely to succeed in low memory
# environments. The kernel's overcommit heustistics bite us
# fairly often, preventing processes such as nix-worker or
# download-using-manifests.pl from forking even if there is
# plenty of free memory.
boot.kernel.sysctl."vm.overcommit_memory" = "1";
# To speed up installation a little bit, include the complete stdenv
# in the Nix store on the CD.
isoImage.storeContents = [ pkgs.stdenv pkgs.busybox ];
}