nixpkgs/modules/system/boot/loader/grub/install-grub.pl
2012-11-15 22:54:43 +01:00

243 lines
7.7 KiB
Perl
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

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 = <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;
}
my $grub = get("grub");
my $grubVersion = int(get("version"));
my $extraConfig = get("extraConfig");
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"));
$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;
}
# 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;
# Add entries for all previous generations of the system profile.
$conf .= "submenu \"NixOS - Old configurations\" {\n" if $grubVersion == 2;
sub nrFromGen { my ($x) = @_; $x =~ /system-(.*)-link/; return $1; }
my @links = sort
{ nrFromGen($b) <=> nrFromGen($a) }
(glob "/nix/var/nix/profiles/system-*-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;
# 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"));
}