#! /usr/bin/perl
#
#use strict; #for debugging
use Cwd 'abs_path';
use Debconf::Client::ConfModule qw(:all);
use POSIX ();
version('2.0');
my $capb = capb('backup', 'escape');

$|=1;

# Predefined values:
my $version           = "=V";
my $link_in_boot      = "=IB";  # Should be empty, mostly
my $no_symlink        = "=S";   # Should be empty, mostly
my $do_symlink        = "Yes";  # target machine defined
my $do_boot_enable    = "Yes";  # target machine defined
my $do_bootloader     = "Yes";  # target machine defined
my $kimage            = "=K";   # Should be empty, mostly
my $loader            = "=L"; # lilo, silo, quik, palo, vmelilo, nettrom, arcboot or delo
my $image_dir         = "=D";        # where the image is located
my $initrd            = "=I";        # initrd kernel
my $mkimage           = "=M";   # command to generate the initrd image
my $use_hard_links    = ''; # hardlinks do not work across fs boundaries
my $postinst_hook     = '';          #Normally we do not
my $minimal_swap      = '';          # Do not swap symlinks
my $ignore_depmod_err = '';          # normally we do not
my $relink_src_link   = 'YES'; # There is no harm in checking the link
my $relink_build_link = 'YES'; # There is no harm in checking the link
my $force_build_link  = '';    # There is no harm in checking the link
my $arch              = "=A"; #  should be same as dpkg --print-architecture
my $kernel_arch       = "=B";
my $ramdisk           = "=MK";  # List of tools to create initial ram fs.
my $package_name      = "=ST-image-$version";
my $explicit_do_loader = '';

my $Loader          = "NoLOADER"; #
$Loader             = "LILO"     if $loader =~ /^lilo/io;
$Loader             = "SILO"     if $loader =~ /^silo/io;
$Loader             = "QUIK"     if $loader =~ /^quik/io;
$Loader             = "yaboot"   if $loader =~ /^yaboot/io;
$Loader             = "PALO"     if $loader =~ /^palo/io;
$Loader             = "NETTROM"  if $loader =~ /^nettrom/io;
$Loader             = "VMELILO"  if $loader =~ /^vmelilo/io;
$Loader             = "ZIPL"     if $loader =~ /^zipl/io;
$Loader             = "ELILO"    if $loader =~ /^elilo/io;
$Loader             = "ARCBOOT"  if $loader =~ /^arcboot/io;
$Loader             = "DELO"     if $loader =~ /^delo/io;

# This should not point to /tmp, because of security risks.
my $temp_file_name = "/var/log/$loader" . "_log.$$";

#known variables
my $image_dest      = "/";
my $realimageloc    = "/$image_dir/";
my $have_conffile   = "";

my $modules_base    = '/lib/modules';
my $CONF_LOC        = '/etc/kernel-img.conf';

# Ignore all invocations except when called on to configure.
exit 0 unless $ARGV[0] =~ /configure/;

my $DEBUG = 0;

# Do some preliminary sanity checks here to ensure we actually have an
# valid image dir
chdir('/')           or die "could not chdir to /:$!\n";
die "Internal Error: ($image_dir) is not a directory!\n"
  unless -d $image_dir;

# remove multiple leading slashes; make sure there is at least one.
$realimageloc  =~ s|^/*|/|o;
$realimageloc  =~ s|/+|/|o;
die "Internal Error: ($realimageloc) is not a directory!\n"
  unless -d $realimageloc;

if (-r "$CONF_LOC" && -f "$CONF_LOC"  ) {
  if (open(CONF, "$CONF_LOC")) {
    while (<CONF>) {
      chomp;
      s/\#.*$//g;
      next if /^\s*$/;

      $do_symlink      = "" if /do_symlinks\s*=\s*(no|false|0)\s*$/ig;
      $no_symlink      = "" if /no_symlinks\s*=\s*(no|false|0)\s*$/ig;
      $link_in_boot    = "" if /link_in_boot\s*=\s*(no|false|0)\s*$/ig;
      $do_boot_enable  = '' if /do_boot_enable\s*=\s*(no|false|0)\s*$/ig;
      $do_bootloader   = '' if /do_bootloader\s*=\s*(no|false|0)\s*$/ig;
      $use_hard_links  = '' if /use_hard_links\s*=\s*(no|false|0)\s*$/ig;
      $minimal_swap    = '' if /minimal_swap\s*=\s*(no|false|0)\s*$/ig;
      $ignore_depmod_err = '' if /ignore_depmod_err\s*=\s*(no|false|0)\s*$/ig;
      $relink_src_link   = '' if /relink_src_link\s*=\s*(no|false|0)\s*$/ig;
      $relink_build_link = '' if /relink_build_link\s*=\s*(no|false|0)\s*$/ig;
      $force_build_link  = '' if /force_build_link\s*=\s*(no|false|0)\s*$/ig;

      $do_symlink      = "Yes" if /do_symlinks\s*=\s*(yes|true|1)\s*$/ig;
      $no_symlink      = "Yes" if /no_symlinks\s*=\s*(yes|true|1)\s*$/ig;
      $link_in_boot    = "Yes" if /link_in_boot\s*=\s*(yes|true|1)\s*$/ig;
      $do_boot_enable  = "Yes" if /do_boot_enable\s*=\s*(yes|true|1)\s*$/ig;
      $do_bootloader   = "Yes" if /do_bootloader\s*=\s*(yes|true|1)\s*$/ig;
      $explicit_do_loader = "YES" if /do_bootloader\s*=\s*(yes|true|1)\s*$/ig;
      $use_hard_links  = "Yes" if /use_hard_links\s*=\s*(yes|true|1)\s*$/ig;
      $minimal_swap    = 'Yes' if /minimal_swap\s*=\s*(yes|true|1)\s*$/ig;
      $ignore_depmod_err = 'Yes' if /ignore_depmod_err\s*=\s*(yes|true|1)\s*$/ig;
      $relink_src_link   = 'Yes' if /relink_src_link\s*=\s*(yes|true|1)\s*$/ig;
      $relink_build_link = 'Yes' if /relink_build_link\s*=\s*(yes|true|1)\s*$/ig;
      $force_build_link = 'Yes' if /force_build_link\s*=\s*(yes|true|1)\s*$/ig;

      $image_dest      = "$1"  if /image_dest\s*=\s*(\S+)/ig;
      $postinst_hook   = "$1"  if /postinst_hook\s*=\s*(\S+)/ig;
      $mkimage         = "$1"  if /mkimage\s*=\s*(.+)$/ig;
      $ramdisk         = "$1"  if /ramdisk\s*=\s*(.+)$/ig;
    }
    close CONF;
    $have_conffile = "Yes";
  }
}


# For some versions of kernel-package, we had this warning in the
# postinst, but the rules did not really interpolate the value in.
# Here is a sanity check.
my $pattern = "=" . "I";
$initrd=~ s/^$pattern$//;

if ($link_in_boot) {
  $image_dest = "/$image_dir/"; # same as realimageloc
}

# Tack on at least one trainling /
$image_dest = "$image_dest/";
$image_dest =~ s|^/*|/|o;
$image_dest =~ s|/+$|/|o;

if (! -d "$image_dest") {
  die "Expected Image Destination dir ($image_dest) to be a valid directory!\n";
}

# sanity
if (! $do_bootloader) {
  $do_boot_enable = '';
}
if ($do_symlink && $no_symlink) {
  warn "Both do_symlinks and no_symlinks options enabled; disabling no_symlinks\n";
  $no_symlink = 0;
}

# most of our work is done in $image_dest (nominally /)
chdir("$image_dest") or die "could not chdir to $image_dest:$!\n";

# Paranoid check to make sure that the correct value is put in there
if    (! $kimage)                 { $kimage = "vmlinuz"; } # Hmm. empty
elsif ($kimage =~ m/^b?zImage$/o) { $kimage = "vmlinuz"; } # these produce vmlinuz
elsif ($kimage =~ m/^[iI]mage$/o) { my $nop = $kimage;   }
elsif ($kimage =~ m/^vmlinux$/o)  { my $nop = $kimage;   }
else                              { $kimage = "vmlinuz"; } # Default

$ENV{KERNEL_ARCH}=$kernel_arch if $kernel_arch;


die "Internal Error: Could not find image (" . $realimageloc
  . "$kimage-$version)\n" unless -e $realimageloc
  . "$kimage-$version";

# search for the boot loader in the path
my $loader_exec;
($loader_exec = $loader)  =~ s|.*/||;
my ($loaderloc) = grep -x, map "$_/$loader_exec",
  map { length($_) ? $_ : "." }  split /:/, $ENV{PATH};


######################################################################
## Fix the build link
######################################################################
sub fix_build_link {
  return unless -d "$modules_base/$version";
  # if we saved a build link in preinst, restore the link
  if (! -e "$modules_base/$version/build" && 
      -l "$modules_base/$version/build.save" ) {
    rename("$modules_base/$version/build.save", "$modules_base/$version/build") ||
      die "failed to move $modules_base/$version/build:$!";
  }
  if ($relink_build_link || $force_build_link) {
    my $build_target;
    my $real_target = '';
    if (-l "$modules_base/$version/build") {
      $build_target = readlink "$modules_base/$version/build";
    } else {
      return;
    }
    # Determine what the real file name is, and test that for existence
    $real_target = abs_path($build_target) if defined($build_target);
    if (!defined($build_target) || ! -d "$real_target") { # Danglink link
      my $num = unlink "$modules_base/$version/build";
      if ($num != 1) {
        warn "error unlinking $modules_base/$version/build";
      } else {
        if ($force_build_link || -d "/usr/src/=ST-headers-$version") {
          my $result = symlink ("/usr/src/=ST-headers-$version",
                                "$modules_base/$version/build");
          if (! $result) {
            warn "Could not link /usr/src/=ST-headers-$version to $modules_base/$version/build:$!"
          }
        }
      }
    }
  }
}

if ($relink_build_link || $force_build_link) {
  &fix_build_link();
}
######################################################################
## Fix the source link
######################################################################
sub fix_source_link {
  return unless -d "$modules_base/$version";
  if ($relink_src_link) {
    my $source_target;
    my $real_target = '';

    if (-l "$modules_base/$version/source") {
      $source_target = readlink "$modules_base/$version/source";
    } else {
      return;
    }
    # Determine what the real file name is, and test that for existence
    $real_target = abs_path($source_target) if defined($source_target);
    if (!defined($source_target) || ! -d "$real_target") { # Danglink link
      my $num = unlink "$modules_base/$version/source";
      if ($num != 1) {
        warn "error unlinking $modules_base/$version/source";
      }
    }
  }
}

if ($relink_src_link) {
  &fix_source_link();
}
######################################################################
######################################################################
###########        Test whether a relative symlinkwould be OK #######
######################################################################
######################################################################
sub test_relative {
  my %params = @_;
  my $cwd;

  die "Internal Error: Missing Required paramater 'Old Dir' "
    unless $params{'Old Dir'};
  die "Internal Error: Missing Required paramater New Dir' "
    unless $params{'New Dir'};


  die "Internal Error: No such dir $params{'Old Dir'} "
    unless -d $params{'Old Dir'};
  die "Internal Error: No such dir $params{'New Dir'} "
    unless -d $params{'New Dir'};

  warn "Test relative: testing $params{'Old Dir'} -> $params{'New Dir'}"
    if $DEBUG;
  chomp($cwd = `pwd`);
  chdir ($params{'New Dir'}) or die "Could not chdir to $params{'New Dir'}:$!";
  my $ok = 0;
  $params{'Old Dir'}  =~ s|^/*||o;
  if (-d $params{'Old Dir'} ) {
    if (defined $params{'Test File'}) {
      if (-e $params{'Old Dir'} . $params{'Test File'}) {
        $ok  = 1;
      }
    } else {
      $ok = 1;                  # well, backward compatibility
    }
  }
  chdir ($cwd) or die "Could not chdir to $params{'New Dir'}:$!";
  return $ok;
}


sub spath {
  my %params = @_;

  die "Missing Required paramater 'Old'" unless $params{'Old'};
  die "Missing Required paramater 'New'" unless  $params{'New'};

  my @olddir  = split '/', `readlink -q -m $params{'Old'}`;
  my @newdir  = split '/', `readlink -q -m $params{'New'}`;
  my @outdir  = @olddir;

  my $out = '';
  my $i;
  for ($i = 0; $i <= $#olddir && $i <= $#newdir; $i++) {
    $out++ if ($olddir[$i] ne $newdir[$i]);
    shift @outdir unless $out;
    unshift @outdir, ".." if $out;
  }
  if ($#newdir > $#olddir) {
    for ($i=0; $i < $#newdir; $i++) {
      unshift @outdir, "..";
    }
  }
  return join ('/', @outdir);
}

# This routine is invoked if there is a symbolic link in place
# in $image_dest/$kimage -- so a symlink exists in the destination.
# What we are trying to determine is if we need to move the symbolic link over
# to the the .old location
sub move_p {
  my $kimage     = $_[0];       # Name of the symbolic link
  my $image_dest = $_[1];       # The directory the links goes into
  my $image_name = $_[2]; 
  my $src_dir    = $_[3]; 
  my $force_move = 0;
  warn "Move?: kimage=$kimage, image_dest=$image_dest, \n" .
    "\timage_name=$image_name, src_dir=$src_dir" if $DEBUG;

  if ($no_symlink) {
    # we do not want links, yet we have a symbolic link here!
    warn "found a symbolic link in " . $image_dest . "$kimage \n" .
      "even though no_symlink is defined\n" if $no_symlink;
    # make sure we change this state of affairs
    $force_move = 1;
    return $force_move;
  }

  warn "DEBUG: OK. We found symlink, and we should have a symlink here.\n"
    if $DEBUG;
  my $vmlinuz_target = readlink "$kimage";
  my $real_target = '';
  my $target = `readlink -q -m "${realimageloc}${kimage}-$version"`;
  $real_target = abs_path($vmlinuz_target) if defined($vmlinuz_target);

  if (!defined($vmlinuz_target) || ! -f "$real_target") {
    # what, a dangling symlink?
    warn "The link "  . $image_dest . "$kimage is a dangling link" .
      "to $real_target\n";
    $force_move = 1;
    return $force_move;
  }


  warn "DEBUG: The link $kimage points to ($vmlinuz_target)\n" if $DEBUG;
  warn "DEBUG: ($vmlinuz_target) is really ($real_target)\n" if $DEBUG;
  my $cwd;
  chomp ($cwd=`pwd`);
  if ($vmlinuz_target !~ m|^/|o) {
    $vmlinuz_target = $cwd . "/" . $vmlinuz_target;
    $vmlinuz_target =~ s|/+|/|o;
  }
  $vmlinuz_target = `readlink -q -m $vmlinuz_target`;

  if ("$vmlinuz_target" ne "$target") {
    warn "DEBUG: We need to handle this.\n" if $DEBUG;
    if ($minimal_swap) {
      warn "DEBUG: Minimal swap.\n" if $DEBUG;
      if (-l "$kimage.old") {
        warn "DEBUG: There is an old link at $kimage.old\n" if $DEBUG;
        my $old_target = readlink "$kimage.old";
        my $real_old_target = '';
        $real_old_target=abs_path($old_target) if defined ($old_target);

        if ($real_old_target  && -f "$real_old_target") {
          if ($old_target !~ m|^/|o) {
            $old_target = $cwd . "/" . $old_target;
            $old_target =~ s|/+|/|o;
          }
          $old_target = `readlink -q -m $old_target`;
          if ("$old_target"  ne "$target") {
            $force_move = 1;
            warn "DEBUG: Old link ($old_target) does not point to us ($target)\n"
              if $DEBUG;
          } 
          else {            # The .old points to the current
            warn "$kimage.old --> $target -- doing nothing";
            $force_move = 0;
          }
        } 
        else { 
          warn "DEBUG: Well, the old link does not exist -- so we move\n"
            if $DEBUG;
          $force_move = 1;
        }
      } 
      else {
        warn "DEBUG: No .old link -- OK to move\n"
          if $DEBUG;
        $force_move = 1;
      }
    } 
    else {
      warn "DEBUG: ok, minimal swap is no-- so we move.\n"
        if $DEBUG;
      $force_move = 1;
    }
  }
  else {                  # already have proper link
    warn "$kimage($vmlinuz_target) points to $target ($real_target) -- doing nothing";
    $force_move = 0;
  }
  return $force_move;
}


# This routine moves the symbolic link around (/vmlinuz -> /vmlinuz.old)
# It pays attention to whether we should the fact whether we should be using
# hard links or not.
sub really_move_link {
  my $kimage     = $_[0];       # Name of the symbolic link
  my $image_dest = $_[1];       # The directory the links goes into
  my $image_name = $_[2]; 
  my $src_dir    = $_[3]; 
  warn "really_move_link: kimage=$kimage, image_dest=$image_dest\n" .
    "\t image_name=$image_name, src_dir=$src_dir" if $DEBUG;

  # don't clobber $kimage.old quite yet
  rename("$kimage", "$kimage.$$") ||
    die "failed to move " . $image_dest . "$kimage:$!";
  my $Old = $src_dir;
  my $cwd;

  chomp($cwd=`pwd`);
  if (test_relative ('Old Dir' => $Old, 'New Dir' => $cwd,
                     'Test File' => "$image_name")) {
    $Old   =~ s|^/*||o;
  }
  # Special case is they are in the same dir
  my $rel_path = spath('Old' => "$Old", 'New' => "$cwd" );
  $Old ="" if $rel_path =~ m/^\s*$/o;

  if ($use_hard_links =~ m/YES/i) {
    if (! link("${Old}${image_name}", "$kimage")) {
      rename("$kimage.$$", "$kimage");
      die("Failed to link ${Old}${image_name} to " .
          "${image_dest}${kimage}.\n");
    }
  } 
  else {
    if (! symlink("${Old}${image_name}", "$kimage")) {
      rename("$kimage.$$", "$kimage");
      die("Failed to symbolic-link ${Old}${image_name} to " .
          "${image_dest}${kimage}.\n");
    }
  }

  # Ok, now we may clobber the previous .old file
  if (-l "$kimage.old" || ! -e "$kimage.old" ) {
    rename("$kimage.$$", "$kimage.old");
  }
  else {
    warn "$kimage.old is not a symlink, not clobbering\n";
    warn "rm $kimage.$$";
  }
}

# This routine handles a request to do symlinks, but there is no
# symlink file already there.  Either we are supposed to use copy, or we are
# installing on a pristine system, or the user does not want symbolic links at
# all.  We use a configuration file to tell the last two cases apart, creating
# a config file if needed.
sub handle_missing_link {
  my $kimage     = $_[0];       # Name of the symbolic link
  my $image_dest = $_[1];       # The directory the links goes into
  my $image_name = $_[2]; 
  my $src_dir    = $_[3]; 
  warn "handle_missing_link: kimage=$kimage, image_dest=$image_dest\n" .
    "\t image_name=$image_name, src_dir=$src_dir" if $DEBUG;

  if ($no_symlink) {
    my $ret = system("cp -a --backup=t " . $realimageloc .
                     "$image_name "   . " $kimage");
    if ($ret) {
      die("Failed to copy " . $realimageloc . "$image_name to "
          . $image_dest . "$kimage .\n");
    }
  } 
  else {
    if (! $have_conffile) {
      # current default
      $do_symlink = "Yes";

      if (open(CONF, ">$CONF_LOC")) {
        print CONF "# Kernel Image management overrides\n";
        if ($loader =~ /palo/i) {
          print CONF "link_in_boot = Yes\n";
          print CONF "do_symlinks = Yes\n";
          print CONF "do_bootloader = No\n";
        }
        close CONF;
      }
      $have_conffile = "Yes";
    }
  }

  if (! $no_symlink && $do_symlink =~ /Yes/i) {
    my $Old = $realimageloc;
    my $New = $image_dest;
    my $Name = "$image_name";
    my $Link_Dest = "$kimage";

    if (test_relative ('Old Dir' => $Old,
                       'New Dir' => $New,
                       'Test File' => $Name)) {
      $Old   =~ s|^/*||o;
    }
    # Special case is they are in the same dir
    my $rel_path = spath('Old' => "$Old", 'New' => "$New" );
    $Old ="" if $rel_path =~ m/^\s*$/o;

    symlink($Old . "$Name", "$Link_Dest") ||
      die("Failed to symbolic-link ${Old}$Name to $Link_Dest.\n");

  }
}

# This routine handles the rest of the cases, where the user has requested 
# non-traditional handling, like using cp or hard links.
sub handle_non_symlinks {
  my $kimage     = $_[0];       # Name of the symbolic link
  my $image_dest = $_[1];       # The directory the links goes into
  my $image_name = $_[2]; 
  my $src_dir    = $_[3]; 
  warn "handle_non_link: kimage=$kimage, image_dest=$image_dest\n" .
    "\t image_name=$image_name, src_dir=$src_dir" if $DEBUG;

  # Save the current image. We do this in all four cases
  rename("$kimage", "$kimage.$$") || 
    die "failed to move " . $image_dest . "$kimage:$!";

  ##,#### 
  # case One
  #`####
  if ($no_symlink) {
    # Maybe /$image_dest is on a dos system?
    my $ret = system("cp -a --backup=t " . $realimageloc
                     . "$image_name " . "$kimage");
    if ($ret) {
      if (-e "$kimage.$$") {
        rename("$kimage.$$", "$kimage");
      }
      die("Failed to copy " . $realimageloc . "$image_name to "
          . $image_dest . "$kimage .\n");
    }
  }
  ##,#### 
  # case Two
  #`####
  elsif ($use_hard_links =~ m/YES/i ) {
    # Ok then. this ought to be a hard link, and hence fair game
    # don't clobber $kimage.old quite yet
    my $Old = $realimageloc;
    my $cwd;
    chomp($cwd=`pwd`);
    if (test_relative ('Old Dir' => $Old, 'New Dir' => $cwd,
                       'Test File' => "$image_name")) {
      $Old   =~ s|^/*||o;
    }
    # Special case is they are in the same dir
    my $rel_path = spath('Old' => "$Old", 'New' => "$cwd" );
    $Old ="" if $rel_path =~ m/^\s*$/o;

    if (! link($Old . "$image_name", "$kimage")) {
      rename("$kimage.$$", "$kimage");
      die("Failed to hard link " . $realimageloc . "$image_name to "
          . $image_dest . "$kimage .\n");
    }
  }
  ##,####
  # case Three
  #`####
  else {
    # We just use cp
    my $ret = system("cp -a --backup=t " . $realimageloc
                     . "$image_name " . "$kimage");
    if ($ret) {
      if (-e "$kimage.$$") {
        rename("$kimage.$$", "$kimage");
      }
      die("Failed to copy " . $realimageloc . "$image_name to "
          . $image_dest . "$kimage .\n");
    }
  }
  # Ok, now we may clobber the previous .old file
  rename("$kimage.$$", "$kimage.old") if -e "$kimage.$$";
}

# This routine is responsible for setting up the symbolic links
# So, the actual kernel image lives in
# $realimageloc/$image_name (/boot/vmlinuz-2.6.12).
# This routine creates symbolic links in $image_dest/$kimage (/vmlinuz)
sub image_magic {
  my $kimage     = $_[0];       # Name of the symbolic link
  my $image_dest = $_[1];       # The directory the links goes into
  my $image_name = "$kimage-$version";
  my $src_dir    = $realimageloc;
  warn "image_magic: kimage=$kimage, image_dest=$image_dest\n" .
    "\t image_name=$image_name, src_dir=$src_dir" if $DEBUG;

  if (-l "$kimage") {           # There is a symbolic link
    warn "DEBUG: There is a symlink for $kimage\n" if $DEBUG;
    my $force_move = move_p($kimage, $image_dest, $image_name, $src_dir);

    if ($force_move) {
      really_move_link($kimage, $image_dest, $image_name, $src_dir);
    }
  }
  elsif (! -e "$kimage") {
    # Hmm. Pristine system? How can that be? Installing from scratch?
    # Or maybe the user does not want a symbolic link here.
    # Possibly they do not want a link here. (we should be in /
    # here[$image_dest, really]
    handle_missing_link($kimage, $image_dest, $image_name, $src_dir);
  }
  elsif (-e "$kimage" ) {
    # OK, $kimage exists -- but is not a link
    handle_non_symlinks($kimage, $image_dest, $image_name, $src_dir);
  }
}

######################################################################
######################################################################
######################################################################
######################################################################

sub do_modules {
  print STDERR "Running depmod.\n";
  my $ret = system("depmod -a -F $realimageloc/System.map-$version $version");
  my $exit_value  = $? >> 8;
  my $signal_num  = $? & 127;
  my $dumped_core = $? & 128;
  if ($ret) {
    my $seen;
    my $answer;
    $question = "${package_name}/postinst/depmod-error-initrd-$version";

    ($ret,$seen) = fset ("$question", 'seen', 'false');
    die "Error setting debconf flags in $question: $seen" if $ret;

    $ret = subst("$question", 'modules_base', "$modules_base");
    die "Error setting debconf substitutions in $question: $seen" if $ret;

    $ret = subst("$question", 'SIGNAL', ", and got a signal $signal_num");
    die "Error setting debconf substitutions in $question: $seen" if $ret;

    if ($dumped_core) {
      $ret = subst("$question", 'CORE', ", and dumped core");
      die "Error setting debconf substitutions in $question: $seen" if $ret;
    }
    else {
      $ret = subst("$question", 'CORE', " ");
      die "Error setting debconf substitutions in $question: $seen" if $ret;
    }

    ($ret,$seen) = input('medium', "$question");
    if ($ret && $ret != 30 ) {
      die "Error setting debconf question $question: $seen";
    }

    ($ret,$seen) = go ();
    if ($ret && $ret != 30 ) {
      die "Error asking debconf question $question: $seen";
    }

    ($ret,$answer) = get("$question");
    die "Error retreiving answer for $question: $answer" if $ret;

    if (! $ignore_depmod_err) {
      if ($answer =~ /^(y|t)/i) {
        exit(1);
      }
      else {
        print STDERR "Ok, continuing as directed\n";
      }
    }
  }

  # If we are installing (not upgrading) a package for a newer
  # upstream version than that of the running kernel, check whether
  # the user might be missing necessary firmware, perhaps because
  # it has now been removed from the kernel.
  #
  # We base this check on the modules used in the running kernel and
  # the corresponding (by name) modules in the new kernel.  This is
  # not entirely accurate because:
  # 1. A device may now be handled by a module with a different name,
  #    leading us to miss the dependency
  # 2. A device may be handled by a module that needs firmware only
  #    for some other device, leading us to claim a dependency wrongly

  if (!defined($ARGV[1]) || $ARGV[1] eq '') {
    (undef, undef, my $running_version) = POSIX::uname();
    my $running_patchlevel = $running_version;
    $running_patchlevel =~ s/^2\.6\.(\d+).*/$1/;
    my $new_patchlevel = $version;
    $new_patchlevel =~ s/^2\.6\.(\d+).*/$1/;

    if ($new_patchlevel > $running_patchlevel) {
      my $missing = '';
      my %module_paths;
      open(DEP, "<$modules_base/$version/modules.dep") or return;
      while (<DEP>) {
	if (m|(.*/([^/]*)\.ko):|) {
	  my ($path, $module) = ($1, $2);
	  $module =~ s/-/_/g;
	  $module_paths{$module} = $path;
	}
      }
      close(DEP);
      open(MODULES, '</proc/modules') or return;
      while (<MODULES>) {
	s/ .*//s;
	my $module = $_;
	my $module_path = $module_paths{$module};
	if (defined($module_path)) {
	  my $first = 1;
	  if ($module_path !~ m|^/|) {
	    $module_path = "$modules_base/$version/$module_path";
	  }
	  open(MODINFO, "modinfo -F firmware '$module_path' |");
	  while (<MODINFO>) {
	    chomp;
	    my $firmware = $_;
	    unless (-e "/lib/firmware/$firmware" ||
		    -e "/lib/firmware/$version/$firmware") {
	      if ($first) {
		$missing .= "\\n" if $missing ne '';
		$missing .= "$module: ";
		$first = 0;
	      } else {
		$missing .= ', ';
	      }
	      $missing .= $firmware;
	    }
	  }
	  close(MODINFO);
	}
      }
      close(MODULES);

      if ($missing ne '') {
	my ($ret, $seen);
	my $text = "${package_name}/postinst/missing-firmware-${version}";

	($ret, $seen) = subst($text, 'runningversion', $running_version);
	die "Error setting debconf substitutions in $text: $seen" if $ret;

	($ret, $seen) = subst($text, 'version', $version);
	die "Error setting debconf substitutions in $text: $seen" if $ret;

	($ret, $seen) = subst($text, 'missing', $missing);
	die "Error setting debconf substitutions in $text: $seen" if $ret;

	($ret, $seen) = input('high', $text);
	if ($ret && $ret != 30) {
	  die "Error setting debconf question $text: $seen";
	}

	($ret, $seen) = go();
	if ($ret && $ret != 30) {
	  die "Error asking debconf question $text: $seen";
	}
      }
    }
  }
}

# We may not have any modules installed
if (-d "$modules_base/$version") {
  &do_modules();
}


sub find_initramfs_tool {
	my $ramdisk = shift;
	my (@tools, $initramfs_cmd);

	foreach $initramfs_cmd  (split(/[:,\s]+/, $ramdisk)) {
		if (system("test -x \"\$(command -v $initramfs_cmd)\"") == 0) {
			push(@tools, $initramfs_cmd);
		}
        }
	return @tools;
}


if ($initrd) {
my @ramdisklist;
@ramdisklist = find_initramfs_tool($ramdisk) if $ramdisk;
die "Failed to find suitable initramfs generation tool in $ramdisk\n"
      if $#ramdisklist < 0;
my $success = 0;
for $ramdisk_cmd (@ramdisklist) {
    print STDERR "Running $ramdisk_cmd.\n";
    print STDERR "Other valid candidates: @ramdisklist\n" if $#ramdisklist > 0;

    my $initrd_path = $realimageloc . "initrd.img-$version";
    my $ret = system("$ramdisk_cmd " .
                     ($mkimage ? "-m '$mkimage' " : "") .
                     "-c -t -k $version >&2");
    if ($ret) {
      warn "$ramdisk_cmd failed to create initrd image.\n";
    } else {
	$success = 1;
	last;
    }
}
die "Failed to create initrd image.\n" unless $success;
if (! defined $ARGV[1] || ! $ARGV[1] || $ARGV[1] =~ m/<unknown>/og) {
    image_magic("initrd.img", $image_dest);
} else {
    if (! -e "initrd.img") {
      handle_missing_link("initrd.img", $image_dest, "initrd.img-$version",
                          $realimageloc);
    }
}
}

# Only change the symlinks if we are not being upgraded
if (! defined $ARGV[1] || ! $ARGV[1] || $ARGV[1] =~ m/<unknown>/og) {
  image_magic($kimage, $image_dest);
}
else {
  if (! -e "$kimage") {
    handle_missing_link($kimage, $image_dest, "$kimage-$version", 
                        $realimageloc);
  }
}

# set the env var stem
$ENV{'STEM'} = "=ST";
sub run_hook {
  my $type   = shift;
  my $script = shift;

  print STDERR "Running $script.\n";
  system ("$script $version $realimageloc$kimage-$version") &&
    print STDERR "User $type hook script [$script] ";
  if ($?) {
    if ($? == -1) {
      print STDERR "failed to execute: $!\n";
    }
    elsif ($? & 127) {
      printf STDERR "died with signal %d, %s coredump\n",
        ($? & 127),  ($? & 128) ? 'with' : 'without';
    }
    else {
      printf STDERR "exited with value %d\n", $? >> 8;
    }
    exit $? >> 8;
  }
}

my $options;
for (@ARGV) {
	s,','\\'',g;
	$options .= " '$_'";
}
$ENV{'DEB_MAINT_PARAMS'}="$options";

## Run user hook script here, if any
if ($postinst_hook) {
  &run_hook("postinst", $postinst_hook);
}

if (-d "/etc/kernel/postinst.d") {
  print STDERR "Examining /etc/kernel/postinst.d.\n";
  system ("run-parts --verbose --exit-on-error --arg=$version " .
          "--arg=$realimageloc$kimage-$version " .
          "/etc/kernel/postinst.d") &&
            die "Failed to process /etc/kernel/postinst.d";
}

if (-d "/etc/kernel/postinst.d/$version") {
  print STDERR "Examining /etc/kernel/postinst.d/$version.\n";
  system ("run-parts --verbose --exit-on-error --arg=$version " .
          "--arg=$realimageloc$kimage-$version " .
          "/etc/kernel/postinst.d/$version") &&
            die "Failed to process /etc/kernel/postinst.d/$version";
}

LOADER: {
  last unless $do_boot_enable; # Exit if explicitly asked to

  last if $loader =~ /silo/i; # SILO does not have to be executed.
  last if $loader =~ /yaboot/i; # yaboot does not have to be executed.
  last if $loader =~ /milo/i; # MILO does not have to be executed.
  last if $loader =~ /nettrom/i; # NETTROM does not have to be executed.
  last if $loader =~ /arcboot/i; # ARCBOOT does not have to be executed.
  last if $loader =~ /delo/i; # DELO does not have to be executed.
  last if $loader =~ /quik/i; # maintainer asked quik invocation to be ignored

  last unless $loaderloc;
  last unless -x $loaderloc;
  last unless $do_bootloader;

  if (-T "/etc/$loader.conf") {
    # Trust and use the existing lilo.conf.
    print STDERR "You already have a $Loader configuration in /etc/$loader.conf\n";
    my $ret = &run_lilo();
    exit $ret if $ret;
  }
}


sub run_lilo (){
  my $ret;
  # Try and figure out if the user really wants lilo to be run --
  # since the default is to run the boot laoder, which is ! grub -- but
  # the user may be using grub now, and not changed the default.

  # So, if the user has explicitly asked for the loader to be run, or
  # if there is no postinst hook, or if there is no grub installed --
  # we are OK. Or else, we ask.
  if ($explicit_do_loader || (! ($postinst_hook && -x '/sbin/grub')))  {
    print STDERR "Running boot loader as requested\n";
  }
  else {
    # Ask the user
    my $seen;
    my $question = "shared/kernel-image/really-run-bootloader";

    print STDERR "Do we really want to run bootloader $loader?\n";

    ($ret,$seen) = fset ("$question", 'seen', 'false');
    die "Error setting debconf flags in $question: $seen" if $ret;

    $ret = subst("$question", 'loader', "$loader");
    die "Error setting debconf substitutions in $question: $seen" if $ret;

    ($ret,$seen) = input('critical', "$question");
    if ($ret && $ret != 30 ) {
      die "Error setting debconf question $question: $seen";
    }

    ($ret,$seen) = go ();
    if ($ret && $ret != 30 ) {
      die "Error asking debconf question $question: $seen";
    }

    ($ret,$answer) = get("$question");
    die "Error retreiving answer for $question: $answer" if $ret;

    if ($answer =~ /^(y|t)/i) {
      print STDERR "Ok, not running $loader\n";
      return 0;
    }
    else {
      print STDERR "Ok, continuing as directed.\n";
    }

  }
  if ($loader =~ /^lilo/io or $loader =~ /vmelilo/io) {
    print STDERR "Testing $loader.conf ... \n";
    unlink $temp_file_name;     # security
    $ret = system("$loaderloc -t >$temp_file_name 2>&1");
    if ($ret) {
      my $seen;
      my $note = "${package_name}/postinst/bootloader-test-error-$version";

      print STDERR "Failed test for bootloader $loader\n";

      ($ret,$seen) = fset ("$note", 'seen', 'false');
      die "Error setting debconf flags in $note: $seen" if $ret;

      $ret = subst("$note", 'loader', "$loader");
      die "Error setting debconf substitutions in $note: $seen" if $ret;

      $ret = subst("$note", 'temp_file_name', "$temp_file_name");
      die "Error setting debconf substitutions in $note: $seen" if $ret;

      ($ret,$seen) = input('critical', "$note");
      if ($ret && $ret != 30 ) {
        die "Error setting debconf note $note: $seen";
      }

      ($ret,$seen) = go ();
      if ($ret && $ret != 30 ) {
        die "Error showing debconf note $note: $seen";
      }
      return $ret;
    }
    unlink "$temp_file_name";
    print STDERR "Testing successful.\n";
    print STDERR "Installing the ";
    print STDERR "partition " if $loader =~ /^lilo/io;
    print STDERR "boot sector... \n";
  }

  print STDERR "Running $loaderloc  ... \n";
  if ($loader =~ /^elilo/io) {
    $ret = system("$loaderloc 2>&1 | tee $temp_file_name");
  } else {
    $ret = system("$loaderloc >$temp_file_name 2>&1");
  }
  if ($ret) {
    my $ret;
    my $seen;
    my $note = "${package_name}/postinst/bootloader-error-$version";

    ($ret,$seen) = fset ("$note", 'seen', 'false');
    die "Error setting debconf flags in $note: $seen" if $ret;

    $ret = subst("$note", 'locader', "$loader");
    die "Error setting debconf substitutions in $note: $seen" if $ret;

    $ret = subst("$note", 'temp_file_name', "$temp_file_name");
    die "Error setting debconf substitutions in $note: $seen" if $ret;

    ($ret,$seen) = input('critical', "$note");
    if ($ret && $ret != 30 ) {
      die "Error setting debconf note $note: $seen";
    }

    ($ret,$seen) = go ();
    if ($ret && $ret != 30 ) {
      die "Error asking debconf question $note: $seen";
    }
    return $ret;
  }
  unlink $temp_file_name;
  print STDERR "Installation successful.\n";
  return 0;
}

exit 0;

__END__