+ my @kernels;
+
+ my $os = $oses{$root_dev}->{os};
+ if ($os eq "linux") {
+ # Installed kernels will have a corresponding /lib/modules/<version>
+ # directory, which is the easiest way to find out what kernels
+ # are installed, and what modules are available.
+ foreach ($g->ls ("/lib/modules")) {
+ if ($g->is_dir ("/lib/modules/$_")) {
+ my %kernel;
+ $kernel{version} = $_;
+
+ # List modules.
+ my @modules;
+ foreach ($g->find ("/lib/modules/$_")) {
+ if (m,/([^/]+)\.ko$, || m,([^/]+)\.o$,) {
+ push @modules, $1;
+ }
+ }
+
+ $kernel{modules} = \@modules;
+
+ push @kernels, \%kernel;
+ }
+ }
+
+ } elsif ($os eq "windows") {
+ # XXX
+ }
+
+ $oses{$root_dev}->{kernels} = \@kernels;
+}
+
+# Check /etc/modprobe.conf to see if there are any specified
+# drivers associated with network (ethX) or hard drives. Normally
+# one might find something like:
+#
+# alias eth0 xennet
+# alias scsi_hostadapter xenblk
+#
+# XXX This doesn't look beyond /etc/modprobe.conf, eg. in /etc/modprobe.d/
+
+sub check_for_modprobe_aliases
+{
+ local $_;
+ my $root_dev = shift;
+
+ # Initialise augeas
+ my $success = 0;
+ $success = $g->aug_init("/", 16);
+
+ # Register /etc/modules.conf and /etc/conf.modules to the Modprobe lens
+ my @results;
+ @results = $g->aug_match("/augeas/load/Modprobe/incl");
+
+ # Calculate the next index of /augeas/load/Modprobe/incl
+ my $i = 1;
+ foreach ( @results ) {
+ next unless m{/augeas/load/Modprobe/incl\[(\d*)]};
+ $i = $1 + 1 if ($1 == $i);
+ }
+
+ $success = $g->aug_set("/augeas/load/Modprobe/incl[$i]",
+ "/etc/modules.conf");
+ $i++;
+ $success = $g->aug_set("/augeas/load/Modprobe/incl[$i]",
+ "/etc/conf.modules");
+
+ # Make augeas reload
+ $success = $g->aug_load();
+
+ my %modprobe_aliases;
+
+ for my $pattern qw(/files/etc/conf.modules/alias
+ /files/etc/modules.conf/alias
+ /files/etc/modprobe.conf/alias
+ /files/etc/modprobe.d/*/alias) {
+ @results = $g->aug_match($pattern);
+
+ for my $path ( @results ) {
+ $path =~ m{^/files(.*)/alias(?:\[\d*\])?$}
+ or die("$path doesn't match augeas pattern");
+ my $file = $1;
+
+ my $alias;
+ $alias = $g->aug_get($path);
+
+ my $modulename;
+ $modulename = $g->aug_get($path.'/modulename');
+
+ my %aliasinfo;
+ $aliasinfo{modulename} = $modulename;
+ $aliasinfo{augeas} = $path;
+ $aliasinfo{file} = $file;
+
+ $modprobe_aliases{$alias} = \%aliasinfo;
+ }
+ }
+
+ $oses{$root_dev}->{modprobe_aliases} = \%modprobe_aliases;
+}
+
+# Get a listing of device drivers in any initrd corresponding to a
+# kernel. This is an indication of what can possibly be booted.
+
+sub check_for_initrd
+{
+ local $_;
+ my $root_dev = shift;
+ my $dir = shift;
+
+ my %initrd_modules;
+
+ foreach my $initrd ($g->ls ("/boot")) {
+ if ($initrd =~ m/^initrd-(.*)\.img$/ && $g->is_file ("/boot/$initrd")) {
+ my $version = $1;
+ my @modules = ();
+ # We have to download these to a temporary file.
+ $g->download ("/boot/$initrd", "$dir/initrd");
+
+ my $cmd = "zcat $dir/initrd | file -";
+ open P, "$cmd |" or die "$cmd: $!";
+ my $lines;
+ { local $/ = undef; $lines = <P>; }
+ close P;
+ if ($lines =~ /ext\d filesystem data/) {
+ # Before initramfs came along, these were compressed
+ # ext2 filesystems. We could run another libguestfs
+ # instance to unpack these, but punt on them for now. (XXX)
+ warn "initrd image is unsupported ext2/3/4 filesystem\n";
+ }
+ elsif ($lines =~ /cpio/) {
+ my $cmd = "zcat $dir/initrd | cpio --quiet -it";
+ open P, "$cmd |" or die "$cmd: $!";
+ while (<P>) {
+ push @modules, $1
+ if m,([^/]+)\.ko$, || m,([^/]+)\.o$,;
+ }
+ close P;
+ unlink "$dir/initrd";
+ $initrd_modules{$version} = \@modules;
+ }
+ else {
+ # What?
+ warn "unrecognized initrd image: $lines\n";
+ }
+ }
+ }
+
+ $oses{$root_dev}->{initrd_modules} = \%initrd_modules;