nixpkgs/modules/installer/cd-dvd/iso-image.nix
Eelco Dolstra c4f910f550 * Substitute the path of the system derivation directly in the stage 2
init script.  This removes the need for the `systemConfig' boot
  parameter; `init=<stage-2-init>' is enough.  However, the GRUB menu
  builder still needs to add `systemConfig' to the kernel command line
  for compatibility with old configurations.

svn path=/nixos/trunk/; revision=23775
2010-09-13 22:10:25 +00:00

255 lines
7.7 KiB
Nix

# This module creates a bootable ISO image containing the given NixOS
# configuration. The derivation for the ISO image will be placed in
# config.system.build.isoImage.
{ config, pkgs, ... }:
with pkgs.lib;
let
options = {
isoImage.isoName = mkOption {
default = "cd.iso";
description = ''
Name of the generated ISO image file.
'';
};
isoImage.compressImage = mkOption {
default = false;
description = ''
Whether the ISO image should be compressed using
<command>bzip2</command>.
'';
};
isoImage.volumeID = mkOption {
default = "NIXOS_BOOT_CD";
description = ''
Specifies the label or volume ID of the generated ISO image.
Note that the label is used by stage 1 of the boot process to
mount the CD, so it should be reasonably distinctive.
'';
};
isoImage.contents = mkOption {
example =
[ { source = pkgs.memtest86 + "/memtest.bin";
target = "boot/memtest.bin";
}
];
description = ''
This option lists files to be copied to fixed locations in the
generated ISO image.
'';
};
isoImage.storeContents = mkOption {
example = [pkgs.stdenv];
description = ''
This option lists additional derivations to be included in the
Nix store in the generated ISO image.
'';
};
isoImage.includeSystemBuildDependencies = mkOption {
default = false;
example = true;
description = ''
Set this option to include all the needed sources etc in the
image. It significantly increases image size. Use that when
you want to be able to keep all the sources needed to build your
system or when you are going to install the system on a computer
with slow on non-existent network connection.
'';
};
};
# The Grub image.
grubImage = pkgs.runCommand "grub_eltorito" {}
''
${pkgs.grub2}/bin/grub-mkimage -o tmp biosdisk iso9660 help linux linux16 sh chain gfxterm vbe png jpeg
cat ${pkgs.grub2}/lib/grub/*/cdboot.img tmp > $out
''; # */
# The configuration file for Grub.
grubCfg =
''
set default=${builtins.toString config.boot.loader.grub.default}
set timeout=${builtins.toString config.boot.loader.grub.timeout}
if loadfont /boot/grub/unicode.pf2; then
set gfxmode=640x480
insmod gfxterm
insmod vbe
terminal_output gfxterm
insmod png
if background_image /boot/grub/splash.png; then
set color_normal=white/black
set color_highlight=black/white
else
set menu_color_normal=cyan/blue
set menu_color_highlight=white/blue
fi
fi
${config.boot.loader.grub.extraEntries}
'';
in
{
require = options;
boot.loader.grub.version = 2;
# Don't build the GRUB menu builder script, since we don't need it
# here and it causes a cyclic dependency.
boot.loader.grub.enable = false;
# !!! Hack - attributes expected by other modules.
system.build.menuBuilder = "true";
system.boot.loader.kernelFile = "bzImage";
environment.systemPackages = [ pkgs.grub2 ];
# In stage 1 of the boot, mount the CD as the root FS by label so
# that we don't need to know its device. We pass the label of the
# root filesystem on the kernel command line, rather than in
# `fileSystems' below. This allows CD-to-USB converters such as
# UNetbootin to rewrite the kernel command line to pass the label or
# UUID of the USB stick. It would be nicer to write
# `root=/dev/disk/by-label/...' here, but UNetbootin doesn't
# recognise that.
boot.kernelParams = [ "root=LABEL=${config.isoImage.volumeID}" ];
# Note that /dev/root is a symlink to the actual root device
# specified on the kernel command line, created in the stage 1 init
# script.
fileSystems =
[ { mountPoint = "/";
device = "/dev/root";
}
{ mountPoint = "/nix/store";
fsType = "squashfs";
device = "/nix-store.squashfs";
options = "loop";
neededForBoot = true;
}
];
# We need squashfs in the initrd to mount the compressed Nix store,
# and aufs to make the root filesystem appear writable.
boot.extraModulePackages =
optional
(! config.boot.kernelPackages.kernel.features ? aufs)
config.boot.kernelPackages.aufs2;
boot.initrd.availableKernelModules = [ "aufs" "squashfs" "iso9660" ];
boot.initrd.kernelModules = [ "loop" ];
# In stage 1, mount a tmpfs on top of / (the ISO image) and
# /nix/store (the squashfs image) to make this a live CD.
boot.initrd.postMountCommands =
''
mkdir /mnt-root-tmpfs
mount -t tmpfs -o "mode=755" none /mnt-root-tmpfs
mkdir /mnt-root-union
mount -t aufs -o dirs=/mnt-root-tmpfs=rw:$targetRoot=ro none /mnt-root-union
targetRoot=/mnt-root-union
mkdir /mnt-store-tmpfs
mount -t tmpfs -o "mode=755" none /mnt-store-tmpfs
mkdir -p $targetRoot/nix/store
mount -t aufs -o dirs=/mnt-store-tmpfs=rw:/mnt-root/nix/store=ro none /mnt-root-union/nix/store
'';
# Closures to be copied to the Nix store on the CD, namely the init
# script and the top-level system configuration directory.
isoImage.storeContents =
[ config.system.build.toplevel ] ++
optional config.isoImage.includeSystemBuildDependencies
config.system.build.toplevel.drvPath;
# Create the squashfs image that contains the Nix store.
system.build.squashfsStore = import ../../../lib/make-squashfs.nix {
inherit (pkgs) stdenv squashfsTools perl pathsFromGraph;
storeContents = config.isoImage.storeContents;
};
# Individual files to be included on the CD, outside of the Nix
# store on the CD.
isoImage.contents =
[ { source = grubImage;
target = "/boot/grub/grub_eltorito";
}
{ source = pkgs.writeText "grub.cfg" grubCfg;
target = "/boot/grub/grub.cfg";
}
{ source = config.boot.kernelPackages.kernel + "/bzImage";
target = "/boot/bzImage";
}
{ source = config.system.build.initialRamdisk + "/initrd";
target = "/boot/initrd";
}
{ source = "${pkgs.grub2}/share/grub/unicode.pf2";
target = "/boot/grub/unicode.pf2";
}
{ source = config.boot.loader.grub.splashImage;
target = "/boot/grub/splash.png";
}
{ source = config.system.build.squashfsStore;
target = "/nix-store.squashfs";
}
{ # Quick hack: need a mount point for the store.
source = pkgs.runCommand "empty" {} "ensureDir $out";
target = "/nix/store";
}
];
# The Grub menu.
boot.loader.grub.extraEntries =
''
menuentry "NixOS Installer / Rescue" {
linux /boot/bzImage init=${config.system.build.toplevel}/init ${toString config.boot.kernelParams}
initrd /boot/initrd
}
menuentry "Boot from hard disk" {
set root=(hd0)
chainloader +1
}
'';
boot.loader.grub.timeout = 10;
# Create the ISO image.
system.build.isoImage = import ../../../lib/make-iso9660-image.nix {
inherit (pkgs) stdenv perl cdrkit pathsFromGraph;
inherit (config.isoImage) isoName compressImage volumeID contents;
bootable = true;
bootImage = "/boot/grub/grub_eltorito";
};
boot.postBootCommands =
''
# After booting, register the contents of the Nix store on the
# CD in the Nix database in the tmpfs.
${config.environment.nix}/bin/nix-store --load-db < /nix/store/nix-path-registration
# nixos-rebuild also requires a "system" profile and an
# /etc/NIXOS tag.
touch /etc/NIXOS
${config.environment.nix}/bin/nix-env -p /nix/var/nix/profiles/system --set /var/run/current-system
'';
}