use strict; use warnings; use XML::LibXML; use File::Basename; use File::Path; use File::stat; use File::Copy; use POSIX; use Cwd; my $defaultConfig = $ARGV[1] or die; my $dom = XML::LibXML->load_xml(location => $ARGV[0]); sub get { my ($name) = @_; return $dom->findvalue("/expr/attrs/attr[\@name = '$name']/*/\@value"); } sub readFile { my ($fn) = @_; local $/ = undef; open FILE, "<$fn" or return undef; my $s = ; close FILE; local $/ = "\n"; chomp $s; return $s; } sub writeFile { my ($fn, $s) = @_; open FILE, ">$fn" or die "cannot create $fn: $!\n"; print FILE $s or die; close FILE or die; } my $grub = get("grub"); my $grubVersion = int(get("version")); my $extraConfig = get("extraConfig"); my $extraPrepareConfig = get("extraPrepareConfig"); my $extraPerEntryConfig = get("extraPerEntryConfig"); my $extraEntries = get("extraEntries"); my $extraEntriesBeforeNixOS = get("extraEntriesBeforeNixOS") eq "true"; my $splashImage = get("splashImage"); my $configurationLimit = int(get("configurationLimit")); my $copyKernels = get("copyKernels") eq "true"; my $timeout = int(get("timeout")); my $defaultEntry = int(get("default")); my $explicitBootRoot = get("explicitBootRoot"); $ENV{'PATH'} = get("path"); die "unsupported GRUB version\n" if $grubVersion != 1 && $grubVersion != 2; print STDERR "updating GRUB $grubVersion menu...\n"; mkpath("/boot/grub", 0, 0700); # Discover whether /boot is on the same filesystem as / and # /nix/store. If not, then all kernels and initrds must be copied to # /boot, and all paths in the GRUB config file must be relative to the # root of the /boot filesystem. `$bootRoot' is the path to be # prepended to paths under /boot. my $bootRoot = "/boot"; if (stat("/")->dev != stat("/boot")->dev) { $bootRoot = ""; $copyKernels = 1; } elsif (stat("/boot")->dev != stat("/nix/store")->dev) { $copyKernels = 1; } if ($explicitBootRoot ne "") { $bootRoot = $explicitBootRoot; } # Generate the header. my $conf .= "# Automatically generated. DO NOT EDIT THIS FILE!\n"; if ($grubVersion == 1) { $conf .= " default $defaultEntry timeout $timeout "; if ($splashImage) { copy $splashImage, "/boot/background.xpm.gz" or die "cannot copy $splashImage to /boot\n"; $conf .= "splashimage $bootRoot/background.xpm.gz\n"; } } else { $conf .= " if [ -s \$prefix/grubenv ]; then load_env fi # ‘grub-reboot’ sets a one-time saved entry, which we process here and # then delete. if [ \"\${saved_entry}\" ]; then # The next line *has* to look exactly like this, otherwise KDM's # reboot feature won't work properly with GRUB 2. set default=\"\${saved_entry}\" set saved_entry= set prev_saved_entry= save_env saved_entry save_env prev_saved_entry set timeout=1 else set default=$defaultEntry set timeout=$timeout fi if loadfont $bootRoot/grub/fonts/unicode.pf2; then set gfxmode=640x480 insmod gfxterm insmod vbe terminal_output gfxterm fi "; if ($splashImage) { # FIXME: GRUB 1.97 doesn't resize the background image if it # doesn't match the video resolution. copy $splashImage, "/boot/background.png" or die "cannot copy $splashImage to /boot\n"; $conf .= " insmod png if background_image $bootRoot/background.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 "; } } $conf .= "$extraConfig\n"; # Generate the menu entries. $conf .= "\n"; my %copied; mkpath("/boot/kernels", 0, 0755) if $copyKernels; sub copyToKernelsDir { my ($path) = @_; return $path unless $copyKernels; $path =~ /\/nix\/store\/(.*)/ or die; my $name = $1; $name =~ s/\//-/g; my $dst = "/boot/kernels/$name"; # Don't copy the file if $dst already exists. This means that we # have to create $dst atomically to prevent partially copied # kernels or initrd if this script is ever interrupted. if (! -e $dst) { my $tmp = "$dst.tmp"; copy $path, $tmp or die "cannot copy $path to $tmp\n"; rename $tmp, $dst or die "cannot rename $tmp to $dst\n"; } $copied{$dst} = 1; return "$bootRoot/kernels/$name"; } sub addEntry { my ($name, $path) = @_; return unless -e "$path/kernel" && -e "$path/initrd"; my $kernel = copyToKernelsDir(Cwd::abs_path("$path/kernel")); my $initrd = copyToKernelsDir(Cwd::abs_path("$path/initrd")); my $xen = -e "$path/xen.gz" ? copyToKernelsDir(Cwd::abs_path("$path/xen.gz")) : undef; # FIXME: $confName my $kernelParams = "systemConfig=" . Cwd::abs_path($path) . " " . "init=" . Cwd::abs_path("$path/init") . " " . readFile("$path/kernel-params"); my $xenParams = $xen && -e "$path/xen-params" ? readFile("$path/xen-params") : ""; if ($grubVersion == 1) { $conf .= "title $name\n"; $conf .= " $extraPerEntryConfig\n" if $extraPerEntryConfig; $conf .= " kernel $xen $xenParams\n" if $xen; $conf .= " " . ($xen ? "module" : "kernel") . " $kernel $kernelParams\n"; $conf .= " " . ($xen ? "module" : "initrd") . " $initrd\n\n"; } else { $conf .= "menuentry \"$name\" {\n"; $conf .= " $extraPerEntryConfig\n" if $extraPerEntryConfig; $conf .= " multiboot $xen $xenParams\n" if $xen; $conf .= " " . ($xen ? "module" : "linux") . " $kernel $kernelParams\n"; $conf .= " " . ($xen ? "module" : "initrd") . " $initrd\n"; $conf .= "}\n\n"; } } # Add default entries. $conf .= "$extraEntries\n" if $extraEntriesBeforeNixOS; addEntry("NixOS - Default", $defaultConfig); $conf .= "$extraEntries\n" unless $extraEntriesBeforeNixOS; # extraEntries could refer to @bootRoot@, which we have to substitute $conf =~ s/\@bootRoot\@/$bootRoot/g; # Emit submenus for all system profiles. sub addProfile { my ($profile, $description) = @_; # Add entries for all generations of this profile. $conf .= "submenu \"$description\" {\n" if $grubVersion == 2; sub nrFromGen { my ($x) = @_; $x =~ /\/\w+-(\d+)-link/; return $1; } my @links = sort { nrFromGen($b) <=> nrFromGen($a) } (glob "$profile-*-link"); my $curEntry = 0; foreach my $link (@links) { last if $curEntry++ >= $configurationLimit; my $date = strftime("%F", localtime(lstat($link)->mtime)); my $version = -e "$link/nixos-version" ? readFile("$link/nixos-version") : basename((glob(dirname(Cwd::abs_path("$link/kernel")) . "/lib/modules/*"))[0]); addEntry("NixOS - Configuration " . nrFromGen($link) . " ($date - $version)", $link); } $conf .= "}\n" if $grubVersion == 2; } addProfile "/nix/var/nix/profiles/system", "NixOS - All configurations"; if ($grubVersion == 2) { for my $profile (glob "/nix/var/nix/profiles/system-profiles/*") { my $name = basename($profile); next unless $name =~ /^\w+$/; addProfile $profile, "NixOS - Profile '$name'"; } } # Run extraPrepareConfig in sh if ($extraPrepareConfig ne "") { system((get("shell"), "-c", $extraPrepareConfig)); } # Atomically update the GRUB config. my $confFile = $grubVersion == 1 ? "/boot/grub/menu.lst" : "/boot/grub/grub.cfg"; my $tmpFile = $confFile . ".tmp"; writeFile($tmpFile, $conf); rename $tmpFile, $confFile or die "cannot rename $tmpFile to $confFile\n"; # Remove obsolete files from /boot/kernels. foreach my $fn (glob "/boot/kernels/*") { next if defined $copied{$fn}; print STDERR "removing obsolete file $fn\n"; unlink $fn; } # Install GRUB if the version changed from the last time we installed # it. FIXME: shouldn't we reinstall if ‘devices’ changed? my $prevVersion = readFile("/boot/grub/version") // ""; if (($ENV{'NIXOS_INSTALL_GRUB'} // "") eq "1" || get("fullVersion") ne $prevVersion) { foreach my $dev ($dom->findnodes('/expr/attrs/attr[@name = "devices"]/list/string/@value')) { $dev = $dev->findvalue(".") or die; next if $dev eq "nodev"; print STDERR "installing the GRUB $grubVersion boot loader on $dev...\n"; system("$grub/sbin/grub-install", "--recheck", Cwd::abs_path($dev)) == 0 or die "$0: installation of GRUB on $dev failed\n"; } writeFile("/boot/grub/version", get("fullVersion")); }