nixpkgs/nixos/modules/system/boot/loader/grub/install-grub.pl
William A. Kennington III 13ca3708b5 Fix #4236
2014-09-23 10:18:05 -07:00

417 lines
14 KiB
Perl
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use strict;
use warnings;
use Class::Struct;
use XML::LibXML;
use File::Basename;
use File::Path;
use File::stat;
use File::Copy;
use File::Slurp;
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 = <FILE>; close FILE;
local $/ = "\n"; chomp $s; return $s;
}
sub writeFile {
my ($fn, $s) = @_;
open FILE, ">$fn" or die "cannot create $fn: $!\n";
print FILE $s or die;
close FILE or die;
}
sub runCommand {
my ($cmd) = @_;
open FILE, "$cmd 2>/dev/null |" or die "Failed to execute: $cmd\n";
my @ret = <FILE>;
close FILE;
return ($?, @ret);
}
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 $fsIdentifier = get("fsIdentifier");
$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.
if (stat("/boot")->dev != stat("/nix/store")->dev) {
$copyKernels = 1;
}
# Discover information about the location of /boot
struct(Fs => {
device => '$',
type => '$',
mount => '$',
});
sub PathInMount {
my ($path, $mount) = @_;
my @splitMount = split /\//, $mount;
my @splitPath = split /\//, $path;
if ($#splitPath < $#splitMount) {
return 0;
}
for (my $i = 0; $i <= $#splitMount; $i++) {
if ($splitMount[$i] ne $splitPath[$i]) {
return 0;
}
}
return 1;
}
sub GetFs {
my ($dir) = @_;
my $bestFs = Fs->new(device => "", type => "", mount => "");
foreach my $fs (read_file("/proc/self/mountinfo")) {
chomp $fs;
my @fields = split / /, $fs;
my $mountPoint = $fields[4];
next unless -d $mountPoint;
my @mountOptions = split /,/, $fields[5];
# Skip the optional fields.
my $n = 6; $n++ while $fields[$n] ne "-"; $n++;
my $fsType = $fields[$n];
my $device = $fields[$n + 1];
my @superOptions = split /,/, $fields[$n + 2];
# Skip the read-only bind-mount on /nix/store.
next if $mountPoint eq "/nix/store" && (grep { $_ eq "rw" } @superOptions) && (grep { $_ eq "ro" } @mountOptions);
# Ensure this matches the intended directory
next unless PathInMount($dir, $mountPoint);
# Is it better than our current match?
if (length($mountPoint) > length($bestFs->mount)) {
$bestFs = Fs->new(device => $device, type => $fsType, mount => $mountPoint);
}
}
return $bestFs;
}
struct (Grub => {
path => '$',
search => '$',
});
my $driveid = 1;
sub GrubFs {
my ($dir) = @_;
my $fs = GetFs($dir);
my $path = "/" . substr($dir, length($fs->mount));
my $search = "";
if ($grubVersion > 1) {
# ZFS is completely separate logic as zpools are always identified by a label
# or custom UUID
if ($fs->type eq 'zfs') {
my $sid = index($fs->device, '/');
if ($sid < 0) {
$search = '--label ' . $fs->device;
$path = '/@' . $path;
} else {
$search = '--label ' . substr($fs->device, 0, $sid);
$path = '/' . substr($fs->device, $sid) . '/@' . $path;
}
} else {
my %types = ('uuid' => '--fs-uuid', 'label' => '--label');
if ($fsIdentifier eq 'provided') {
# If the provided dev is identifying the partition using a label or uuid,
# we should get the label / uuid and do a proper search
my @matches = $fs->device =~ m/\/dev\/disk\/by-(label|uuid)\/(.*)/;
if ($#matches > 1) {
die "Too many matched devices"
} elsif ($#matches == 1) {
$search = "$types{$matches[0]} $matches[1]"
}
} else {
# Determine the identifying type
$search = $types{$fsIdentifier} . ' ';
# Based on the type pull in the identifier from the system
my ($status, @devInfo) = runCommand("blkid -o export @{[$fs->device]}");
if ($status != 0) {
die "Failed to get blkid info for @{[$fs->mount]} on @{[$fs->device]}";
}
my @matches = join("", @devInfo) =~ m/@{[uc $fsIdentifier]}=([^\n]*)/;
if ($#matches != 0) {
die "Couldn't find a $types{$fsIdentifier} for @{[$fs->device]}\n"
}
$search .= $matches[0];
}
# BTRFS is a special case in that we need to fix the referrenced path based on subvolumes
if ($fs->type eq 'btrfs') {
my ($status, @id_info) = runCommand("btrfs subvol show @{[$fs->mount]}");
if ($status != 0) {
die "Failed to retrieve subvolume info for @{[$fs->mount]}\n";
}
my @ids = join("", @id_info) =~ m/Object ID:[ \t\n]*([^ \t\n]*)/;
if ($#ids > 0) {
die "Btrfs subvol name for @{[$fs->device]} listed multiple times in mount\n"
} elsif ($#ids == 0) {
my ($status, @path_info) = runCommand("btrfs subvol list @{[$fs->mount]}");
if ($status != 0) {
die "Failed to find @{[$fs->mount]} subvolume id from btrfs\n";
}
my @paths = join("", @path_info) =~ m/ID $ids[0] [^\n]* path ([^\n]*)/;
if ($#paths > 0) {
die "Btrfs returned multiple paths for a single subvolume id, mountpoint @{[$fs->mount]}\n";
} elsif ($#paths != 0) {
die "Btrfs did not return a path for the subvolume at @{[$fs->mount]}\n";
}
$path = "/$paths[0]$path";
}
}
}
if (not $search eq "") {
$search = "search --set=drive$driveid " . $search;
$path = "(\$drive$driveid)$path";
$driveid += 1;
}
}
return Grub->new(path => $path, search => $search);
}
my $grubBoot = GrubFs("/boot");
my $grubStore;
if ($copyKernels == 0) {
$grubStore = GrubFs("/nix/store");
}
# 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 " . $grubBoot->path . "/background.xpm.gz\n";
}
}
else {
if ($copyKernels == 0) {
$conf .= "
" . $grubStore->search;
}
$conf .= "
" . $grubBoot->search . "
if [ -s \$prefix/grubenv ]; then
load_env
fi
# grub-reboot sets a one-time saved entry, which we process here and
# then delete.
if [ \"\${saved_entry}\" ]; then
# The next line *has* to look exactly like this, otherwise KDM's
# reboot feature won't work properly with GRUB 2.
set default=\"\${saved_entry}\"
set saved_entry=
set prev_saved_entry=
save_env saved_entry
save_env prev_saved_entry
set timeout=1
else
set default=$defaultEntry
set timeout=$timeout
fi
if loadfont " . $grubBoot->path . "/grub/fonts/unicode.pf2; then
set gfxmode=640x480
insmod gfxterm
insmod vbe
terminal_output gfxterm
fi
";
if ($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 " . $grubBoot->path . "/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 $grubStore->path . substr($path, length("/nix/store")) 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 $grubBoot->path . "/kernels/$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 .= $grubBoot->search . "\n";
if ($copyKernels == 0) {
$conf .= $grubStore->search . "\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
$conf =~ s/\@bootRoot\@/$grubBoot->path/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"));
}