scripts/kconfig/streamline_config.pl

   1 #!/usr/bin/perl -w
   2 #
   3 # Copywrite 2005-2009 - Steven Rostedt
   4 # Licensed under the terms of the GNU GPL License version 2
   5 #
   6 #  It's simple enough to figure out how this works.
   7 #  If not, then you can ask me at stripconfig@goodmis.org
   8 #
   9 # What it does?
  10 #
  11 #   If you have installed a Linux kernel from a distribution
  12 #   that turns on way too many modules than you need, and
  13 #   you only want the modules you use, then this program
  14 #   is perfect for you.
  15 #
  16 #   It gives you the ability to turn off all the modules that are
  17 #   not loaded on your system.
  18 #
  19 # Howto:
  20 #
  21 #  1. Boot up the kernel that you want to stream line the config on.
  22 #  2. Change directory to the directory holding the source of the
  23 #       kernel that you just booted.
  24 #  3. Copy the configuraton file to this directory as .config
  25 #  4. Have all your devices that you need modules for connected and
  26 #      operational (make sure that their corresponding modules are loaded)
  27 #  5. Run this script redirecting the output to some other file
  28 #       like config_strip.
  29 #  6. Back up your old config (if you want too).
  30 #  7. copy the config_strip file to .config
  31 #  8. Run "make oldconfig"
  32 #
  33 #  Now your kernel is ready to be built with only the modules that
  34 #  are loaded.
  35 #
  36 # Here's what I did with my Debian distribution.
  37 #
  38 #    cd /usr/src/linux-2.6.10
  39 #    cp /boot/config-2.6.10-1-686-smp .config
  40 #    ~/bin/streamline_config > config_strip
  41 #    mv .config config_sav
  42 #    mv config_strip .config
  43 #    make oldconfig
  44 #
  45 my $config = ".config";
  46 my $linuxpath = ".";
  47
  48 my $uname = `uname -r`;
  49 chomp $uname;
  50
  51 my @searchconfigs = (
  52         {
  53             "file" => ".config",
  54             "exec" => "cat",
  55         },
  56         {
  57             "file" => "/proc/config.gz",
  58             "exec" => "zcat",
  59         },
  60         {
  61             "file" => "/boot/config-$uname",
  62             "exec" => "cat",
  63         },
  64         {
  65             "file" => "/boot/vmlinuz-$uname",
  66             "exec" => "scripts/extract-ikconfig",
  67             "test" => "scripts/extract-ikconfig",
  68         },
  69         {
  70             "file" => "vmlinux",
  71             "exec" => "scripts/extract-ikconfig",
  72             "test" => "scripts/extract-ikconfig",
  73         },
  74         {
  75             "file" => "/lib/modules/$uname/kernel/kernel/configs.ko",
  76             "exec" => "scripts/extract-ikconfig",
  77             "test" => "scripts/extract-ikconfig",
  78         },
  79         {
  80             "file" => "kernel/configs.ko",
  81             "exec" => "scripts/extract-ikconfig",
  82             "test" => "scripts/extract-ikconfig",
  83         },
  84         {
  85             "file" => "kernel/configs.o",
  86             "exec" => "scripts/extract-ikconfig",
  87             "test" => "scripts/extract-ikconfig",
  88         },
  89 );
  90
  91 sub find_config {
  92     foreach my $conf (@searchconfigs) {
  93         my $file = $conf->{"file"};
  94
  95         next if ( ! -f "$file");
  96
  97         if (defined($conf->{"test"})) {
  98             `$conf->{"test"} $conf->{"file"} 2>/dev/null`;
  99             next if ($?);
 100         }
 101
 102         my $exec = $conf->{"exec"};
 103
 104         print STDERR "using config: '$file'\n";
 105
 106         open(CIN, "$exec $file |") || die "Failed to run $exec $file";
 107         return;
 108     }
 109     die "No config file found";
 110 }
 111
 112 find_config;
 113
 114 my @makefiles = `find $linuxpath -name Makefile`;
 115 my %depends;
 116 my %selects;
 117 my %prompts;
 118 my %objects;
 119 my $var;
 120 my $cont = 0;
 121
 122 # Get the top level Kconfig file (passed in)
 123 my $kconfig = $ARGV[0];
 124
 125 # prevent recursion
 126 my %read_kconfigs;
 127
 128 sub read_kconfig {
 129     my ($kconfig) = @_;
 130
 131     my $state = "NONE";
 132     my $config;
 133     my @kconfigs;
 134
 135     open(KIN, $kconfig) || die "Can't open $kconfig";
 136     while (<KIN>) {
 137         chomp;
 138
 139         # collect any Kconfig sources
 140         if (/^source\s*"(.*)"/) {
 141             $kconfigs[$#kconfigs+1] = $1;
 142         }
 143
 144         # configs found
 145         if (/^\s*config\s+(\S+)\s*$/) {
 146             $state = "NEW";
 147             $config = $1;
 148
 149         # collect the depends for the config
 150         } elsif ($state eq "NEW" && /^\s*depends\s+on\s+(.*)$/) {
 151             $state = "DEP";
 152             $depends{$config} = $1;
 153         } elsif ($state eq "DEP" && /^\s*depends\s+on\s+(.*)$/) {
 154             $depends{$config} .= " " . $1;
 155
 156         # Get the configs that select this config
 157         } elsif ($state ne "NONE" && /^\s*select\s+(\S+)/) {
 158             if (defined($selects{$1})) {
 159                 $selects{$1} .= " " . $config;
 160             } else {
 161                 $selects{$1} = $config;
 162             }
 163
 164         # configs without prompts must be selected
 165         } elsif ($state ne "NONE" && /^\s*tristate\s\S/) {
 166             # note if the config has a prompt
 167             $prompt{$config} = 1;
 168
 169         # stop on "help"
 170         } elsif (/^\s*help\s*$/) {
 171             $state = "NONE";
 172         }
 173     }
 174     close(KIN);
 175
 176     # read in any configs that were found.
 177     foreach $kconfig (@kconfigs) {
 178         if (!defined($read_kconfigs{$kconfig})) {
 179             $read_kconfigs{$kconfig} = 1;
 180             read_kconfig($kconfig);
 181         }
 182     }
 183 }
 184
 185 if ($kconfig) {
 186     read_kconfig($kconfig);
 187 }
 188
 189 # Read all Makefiles to map the configs to the objects
 190 foreach my $makefile (@makefiles) {
 191     chomp $makefile;
 192
 193     open(MIN,$makefile) || die "Can't open $makefile";
 194     while (<MIN>) {
 195         my $objs;
 196
 197         # is this a line after a line with a backslash?
 198         if ($cont && /(\S.*)$/) {
 199             $objs = $1;
 200         }
 201         $cont = 0;
 202
 203         # collect objects after obj-$(CONFIG_FOO_BAR)
 204         if (/obj-\$\((CONFIG_[^\)]*)\)\s*[+:]?=\s*(.*)/) {
 205             $var = $1;
 206             $objs = $2;
 207         }
 208         if (defined($objs)) {
 209             # test if the line ends with a backslash
 210             if ($objs =~ m,(.*)\\$,) {
 211                 $objs = $1;
 212                 $cont = 1;
 213             }
 214
 215             foreach my $obj (split /\s+/,$objs) {
 216                 $obj =~ s/-/_/g;
 217                 if ($obj =~ /(.*)\.o$/) {
 218                     # Objects may bes enabled by more than one config.
 219                     # Store configs in an array.
 220                     my @arr;
 221
 222                     if (defined($objects{$1})) {
 223                         @arr = @{$objects{$1}};
 224                     }
 225
 226                     $arr[$#arr+1] = $var;
 227
 228                     # The objects have a hash mapping to a reference
 229                     # of an array of configs.
 230                     $objects{$1} = \@arr;
 231                 }
 232             }
 233         }
 234     }
 235     close(MIN);
 236 }
 237
 238 my %modules;
 239
 240 # see what modules are loaded on this system
 241 open(LIN,"/sbin/lsmod|") || die "Cant lsmod";
 242 while (<LIN>) {
 243         next if (/^Module/);  # Skip the first line.
 244         if (/^(\S+)/) {
 245                 $modules{$1} = 1;
 246         }
 247 }
 248 close (LIN);
 249
 250 # add to the configs hash all configs that are needed to enable
 251 # a loaded module.
 252 my %configs;
 253 foreach my $module (keys(%modules)) {
 254     if (defined($objects{$module})) {
 255         @arr = @{$objects{$module}};
 256         foreach my $conf (@arr) {
 257             $configs{$conf} = $module;
 258         }
 259     } else {
 260         # Most likely, someone has a custom (binary?) module loaded.
 261         print STDERR "$module config not found!!\n";
 262     }
 263 }
 264
 265 my $valid = "A-Za-z_0-9";
 266 my $repeat = 1;
 267
 268 #
 269 # Note, we do not care about operands (like: &&, ||, !) we want to add any
 270 # config that is in the depend list of another config. This script does
 271 # not enable configs that are not already enabled. If we come across a
 272 # config A that depends on !B, we can still add B to the list of depends
 273 # to keep on. If A was on in the original config, B would not have been
 274 # and B would not be turned on by this script.
 275 #
 276 sub parse_config_dep_select
 277 {
 278     my ($p) = @_;
 279
 280     while ($p =~ /[$valid]/) {
 281
 282         if ($p =~ /^[^$valid]*([$valid]+)/) {
 283             my $conf = "CONFIG_" . $1;
 284
 285             $p =~ s/^[^$valid]*[$valid]+//;
 286
 287             if (!defined($configs{$conf})) {
 288                 # We must make sure that this config has its
 289                 # dependencies met.
 290                 $repeat = 1; # do again
 291                 $configs{$conf} = 1;
 292             }
 293         } else {
 294             die "this should never happen";
 295         }
 296     }
 297 }
 298
 299 while ($repeat) {
 300     $repeat = 0;
 301
 302     foreach my $config (keys %configs) {
 303         $config =~ s/^CONFIG_//;
 304
 305         if (defined($depends{$config})) {
 306             # This config has dependencies. Make sure they are also included
 307             parse_config_dep_select $depends{$config};
 308         }
 309
 310         if (defined($prompt{$config}) || !defined($selects{$config})) {
 311             next;
 312         }
 313
 314         # config has no prompt and must be selected.
 315         parse_config_dep_select $selects{$config};
 316     }
 317 }
 318
 319 my %setconfigs;
 320
 321 # Finally, read the .config file and turn off any module enabled that
 322 # we could not find a reason to keep enabled.
 323 while(<CIN>) {
 324
 325     if (/CONFIG_IKCONFIG/) {
 326         if (/# CONFIG_IKCONFIG is not set/) {
 327             # enable IKCONFIG at least as a module
 328             print "CONFIG_IKCONFIG=m\n";
 329             # don't ask about PROC
 330             print "# CONFIG_IKCONFIG_PROC is not set\n";
 331         } else {
 332             print;
 333         }
 334         next;
 335     }
 336
 337     if (/^(CONFIG.*)=(m|y)/) {
 338         if (defined($configs{$1})) {
 339             $setconfigs{$1} = $2;
 340         } elsif ($2 eq "m") {
 341             print "# $1 is not set\n";
 342             next;
 343         }
 344     }
 345     print;
 346 }
 347 close(CIN);
 348
 349 # Integrity check, make sure all modules that we want enabled do
 350 # indeed have their configs set.
 351 loop:
 352 foreach my $module (keys(%modules)) {
 353     if (defined($objects{$module})) {
 354         my @arr = @{$objects{$module}};
 355         foreach my $conf (@arr) {
 356             if (defined($setconfigs{$conf})) {
 357                 next loop;
 358             }
 359         }
 360         print STDERR "module $module did not have configs";
 361         foreach my $conf (@arr) {
 362             print STDERR " " , $conf;
 363         }
 364         print STDERR "\n";
 365     }
 366 }