+# 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;
+
+ my @lines;
+ eval { @lines = $g->read_lines ("/etc/modprobe.conf"); };
+ return if $@ || !@lines;
+
+ my %modprobe_aliases;
+
+ foreach (@lines) {
+ $modprobe_aliases{$1} = $2 if /^\s*alias\s+(\S+)\s+(\S+)/;
+ }
+
+ $oses{$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;
+}
+