scripts/mkknlimg

   1 #!/usr/bin/env perl
   2
   3 use strict;
   4 use integer;
   5
   6 my $trailer_magic = 'RPTL';
   7
   8 my $tmpfile1 = "/tmp/mkknlimg_$$.1";
   9 my $tmpfile2 = "/tmp/mkknlimg_$$.2";
  10
  11 my $dtok = 0;
  12
  13 while ($ARGV[0] =~ /^-/)
  14 {
  15     my $arg = shift(@ARGV);
  16     if ($arg eq '--dtok')
  17     {
  18         $dtok = 1;
  19     }
  20     else
  21     {
  22         print ("* Unknown option '$arg'\n");
  23         usage();
  24     }
  25 }
  26
  27 usage() if (@ARGV != 2);
  28
  29 my $kernel_file = $ARGV[0];
  30 my $out_file = $ARGV[1];
  31
  32 if (! -r $kernel_file)
  33 {
  34     print ("* File '$kernel_file' not found\n");
  35     usage();
  36 }
  37
  38 my @wanted_config_lines =
  39 (
  40         'CONFIG_BCM2708_DT'
  41 );
  42
  43 my @wanted_strings =
  44 (
  45         'bcm2708_fb',
  46         'brcm,bcm2708-pinctrl',
  47         'brcm,bcm2835-gpio',
  48         'of_find_property'
  49 );
  50
  51 my $res = try_extract($kernel_file, $tmpfile1);
  52 $res = try_decompress('\037\213\010', 'xy',    'gunzip', 0,
  53                       $kernel_file, $tmpfile1, $tmpfile2) if (!$res);
  54 $res = try_decompress('\3757zXZ\000', 'abcde', 'unxz --single-stream', -1,
  55                       $kernel_file, $tmpfile1, $tmpfile2) if (!$res);
  56 $res = try_decompress('BZh',          'xy',    'bunzip2', 0,
  57                       $kernel_file, $tmpfile1, $tmpfile2) if (!$res);
  58 $res = try_decompress('\135\0\0\0',   'xxx',   'unlzma', 0,
  59                       $kernel_file, $tmpfile1, $tmpfile2) if (!$res);
  60 $res = try_decompress('\211\114\132', 'xy',    'lzop -d', 0,
  61                       $kernel_file, $tmpfile1, $tmpfile2) if (!$res);
  62 $res = try_decompress('\002\041\114\030', 'xy',    'lz4 -d', 1,
  63                       $kernel_file, $tmpfile1, $tmpfile2) if (!$res);
  64
  65 my $append_trailer;
  66 my $trailer;
  67
  68 $append_trailer = $dtok;
  69
  70 if ($res)
  71 {
  72     print("Version: $res->{''}\n");
  73
  74     $append_trailer = $dtok;
  75     if (!$dtok)
  76     {
  77         if (config_bool($res, 'bcm2708_fb'))
  78         {
  79             $dtok ||= config_bool($res, 'CONFIG_BCM2708_DT');
  80             $dtok ||= config_bool($res, 'brcm,bcm2708-pinctrl');
  81             $dtok ||= config_bool($res, 'brcm,bcm2835-gpio');
  82             $append_trailer = 1;
  83         }
  84         else
  85         {
  86             print ("* This doesn't look like a Raspberry Pi kernel. In pass-through mode.\n");
  87         }
  88     }
  89 }
  90 elsif (!$dtok)
  91 {
  92     print ("* Is this a valid kernel? In pass-through mode.\n");
  93 }
  94
  95 if ($append_trailer)
  96 {
  97     printf("DT: %s\n", $dtok ? "y" : "n");
  98
  99     my @atoms;
 100
 101     push @atoms, [ $trailer_magic, pack('V', 0) ];
 102     push @atoms, [ 'KVer', $res->{''} ];
 103     push @atoms, [ 'DTOK', pack('V', $dtok) ];
 104
 105     $trailer = pack_trailer(\@atoms);
 106     $atoms[0]->[1] = pack('V', length($trailer));
 107
 108     $trailer = pack_trailer(\@atoms);
 109 }
 110
 111 my $ofh;
 112 my $total_len = 0;
 113
 114 if ($out_file eq $kernel_file)
 115 {
 116     die "* Failed to open '$out_file' for append\n"
 117         if (!open($ofh, '>>', $out_file));
 118     $total_len = tell($ofh);
 119 }
 120 else
 121 {
 122     die "* Failed to open '$kernel_file'\n"
 123         if (!open(my $ifh, '<', $kernel_file));
 124     die "* Failed to create '$out_file'\n"
 125         if (!open($ofh, '>', $out_file));
 126
 127     my $copybuf;
 128     while (1)
 129     {
 130         my $bytes = sysread($ifh, $copybuf, 64*1024);
 131         last if (!$bytes);
 132         syswrite($ofh, $copybuf, $bytes);
 133         $total_len += $bytes;
 134     }
 135     close($ifh);
 136 }
 137
 138 if ($trailer)
 139 {
 140     # Pad to word-alignment
 141     syswrite($ofh, "\x000\x000\x000", (-$total_len & 0x3));
 142     syswrite($ofh, $trailer);
 143 }
 144
 145 close($ofh);
 146
 147 exit($trailer ? 0 : 1);
 148
 149 END {
 150         unlink($tmpfile1) if ($tmpfile1);
 151         unlink($tmpfile2) if ($tmpfile2);
 152 }
 153
 154
 155 sub usage
 156 {
 157         print ("Usage: mkknlimg [--dtok] <vmlinux|zImage|bzImage> <outfile>\n");
 158         exit(1);
 159 }
 160
 161 sub try_extract
 162 {
 163         my ($knl, $tmp) = @_;
 164
 165         my $ver = `strings "$knl" | grep -a -E "^Linux version [1-9]"`;
 166
 167         return undef if (!$ver);
 168
 169         chomp($ver);
 170
 171         my $res = { ''=>$ver };
 172         my $string_pattern = '^('.join('|', @wanted_strings).')$';
 173
 174         my @matches = `strings \"$knl\" | grep -E \"$string_pattern\"`;
 175         foreach my $match (@matches)
 176         {
 177             chomp($match);
 178             $res->{$match} = 1;
 179         }
 180
 181         my $config_pattern = '^('.join('|', @wanted_config_lines).')=(.*)$';
 182         my $cf1 = 'IKCFG_ST\037\213\010';
 183         my $cf2 = '0123456789';
 184
 185         my $pos = `tr "$cf1\n$cf2" "\n$cf2=" < "$knl" | grep -abo "^$cf2"`;
 186         if ($pos)
 187         {
 188                 $pos =~ s/:.*[\r\n]*$//s;
 189                 $pos += 8;
 190                 my $err = (system("tail -c+$pos \"$knl\" | zcat > $tmp 2> /dev/null") >> 8);
 191                 if (($err == 0) || ($err == 2))
 192                 {
 193                         if (open(my $fh, '<', $tmp))
 194                         {
 195                                 while (my $line = <$fh>)
 196                                 {
 197                                         chomp($line);
 198                                         $res->{$1} = $2 if ($line =~ /$config_pattern/);
 199                                 }
 200
 201                                 close($fh);
 202                         }
 203                 }
 204         }
 205
 206         return $res;
 207 }
 208
 209
 210 sub try_decompress
 211 {
 212         my ($magic, $subst, $zcat, $idx, $knl, $tmp1, $tmp2) = @_;
 213
 214         my $pos = `tr "$magic\n$subst" "\n$subst=" < "$knl" | grep -abo "^$subst"`;
 215         if ($pos)
 216         {
 217                 chomp($pos);
 218                 $pos = (split(/[\r\n]+/, $pos))[$idx];
 219                 $pos =~ s/:.*[\r\n]*$//s;
 220                 my $cmd = "tail -c+$pos \"$knl\" | $zcat > $tmp2 2> /dev/null";
 221                 my $err = (system($cmd) >> 8);
 222                 return undef if (($err != 0) && ($err != 2));
 223
 224                 return try_extract($tmp2, $tmp1);
 225         }
 226
 227         return undef;
 228 }
 229
 230 sub pack_trailer
 231 {
 232         my ($atoms) = @_;
 233         my $trailer = pack('VV', 0, 0);
 234         for (my $i = $#$atoms; $i>=0; $i--)
 235         {
 236                 my $atom = $atoms->[$i];
 237                 $trailer .= pack('a*x!4Va4', $atom->[1], length($atom->[1]), $atom->[0]);
 238         }
 239         return $trailer;
 240 }
 241
 242 sub config_bool
 243 {
 244         my ($configs, $wanted) = @_;
 245         return (($configs->{$wanted} eq 'y') || ($configs->{$wanted} eq '1'));
 246 }