1#!/usr/bin/perl -w 2# 3# Copyright 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# 45use strict; 46 47my $config = ".config"; 48 49my $uname = `uname -r`; 50chomp $uname; 51 52my @searchconfigs = ( 53 { 54 "file" => ".config", 55 "exec" => "cat", 56 }, 57 { 58 "file" => "/proc/config.gz", 59 "exec" => "zcat", 60 }, 61 { 62 "file" => "/boot/config-$uname", 63 "exec" => "cat", 64 }, 65 { 66 "file" => "/boot/vmlinuz-$uname", 67 "exec" => "scripts/extract-ikconfig", 68 "test" => "scripts/extract-ikconfig", 69 }, 70 { 71 "file" => "vmlinux", 72 "exec" => "scripts/extract-ikconfig", 73 "test" => "scripts/extract-ikconfig", 74 }, 75 { 76 "file" => "/lib/modules/$uname/kernel/kernel/configs.ko", 77 "exec" => "scripts/extract-ikconfig", 78 "test" => "scripts/extract-ikconfig", 79 }, 80 { 81 "file" => "kernel/configs.ko", 82 "exec" => "scripts/extract-ikconfig", 83 "test" => "scripts/extract-ikconfig", 84 }, 85 { 86 "file" => "kernel/configs.o", 87 "exec" => "scripts/extract-ikconfig", 88 "test" => "scripts/extract-ikconfig", 89 }, 90); 91 92sub find_config { 93 foreach my $conf (@searchconfigs) { 94 my $file = $conf->{"file"}; 95 96 next if ( ! -f "$file"); 97 98 if (defined($conf->{"test"})) { 99 `$conf->{"test"} $conf->{"file"} 2>/dev/null`; 100 next if ($?); 101 } 102 103 my $exec = $conf->{"exec"}; 104 105 print STDERR "using config: '$file'\n"; 106 107 open(CIN, "$exec $file |") || die "Failed to run $exec $file"; 108 return; 109 } 110 die "No config file found"; 111} 112 113find_config; 114 115# Get the build source and top level Kconfig file (passed in) 116my $ksource = $ARGV[0]; 117my $kconfig = $ARGV[1]; 118my $lsmod_file = $ARGV[2]; 119 120my @makefiles = `find $ksource -name Makefile 2>/dev/null`; 121chomp @makefiles; 122 123my %depends; 124my %selects; 125my %prompts; 126my %objects; 127my $var; 128my $iflevel = 0; 129my @ifdeps; 130 131# prevent recursion 132my %read_kconfigs; 133 134sub read_kconfig { 135 my ($kconfig) = @_; 136 137 my $state = "NONE"; 138 my $config; 139 my @kconfigs; 140 141 my $cont = 0; 142 my $line; 143 144 my $source = "$ksource/$kconfig"; 145 my $last_source = ""; 146 147 # Check for any environment variables used 148 while ($source =~ /\$(\w+)/ && $last_source ne $source) { 149 my $env = $1; 150 $last_source = $source; 151 $source =~ s/\$$env/$ENV{$env}/; 152 } 153 154 open(KIN, "$source") || die "Can't open $kconfig"; 155 while (<KIN>) { 156 chomp; 157 158 # Make sure that lines ending with \ continue 159 if ($cont) { 160 $_ = $line . " " . $_; 161 } 162 163 if (s/\\$//) { 164 $cont = 1; 165 $line = $_; 166 next; 167 } 168 169 $cont = 0; 170 171 # collect any Kconfig sources 172 if (/^source\s*"(.*)"/) { 173 $kconfigs[$#kconfigs+1] = $1; 174 } 175 176 # configs found 177 if (/^\s*(menu)?config\s+(\S+)\s*$/) { 178 $state = "NEW"; 179 $config = $2; 180 181 for (my $i = 0; $i < $iflevel; $i++) { 182 if ($i) { 183 $depends{$config} .= " " . $ifdeps[$i]; 184 } else { 185 $depends{$config} = $ifdeps[$i]; 186 } 187 $state = "DEP"; 188 } 189 190 # collect the depends for the config 191 } elsif ($state eq "NEW" && /^\s*depends\s+on\s+(.*)$/) { 192 $state = "DEP"; 193 $depends{$config} = $1; 194 } elsif ($state eq "DEP" && /^\s*depends\s+on\s+(.*)$/) { 195 $depends{$config} .= " " . $1; 196 197 # Get the configs that select this config 198 } elsif ($state ne "NONE" && /^\s*select\s+(\S+)/) { 199 if (defined($selects{$1})) { 200 $selects{$1} .= " " . $config; 201 } else { 202 $selects{$1} = $config; 203 } 204 205 # configs without prompts must be selected 206 } elsif ($state ne "NONE" && /^\s*tristate\s\S/) { 207 # note if the config has a prompt 208 $prompts{$config} = 1; 209 210 # Check for if statements 211 } elsif (/^if\s+(.*\S)\s*$/) { 212 my $deps = $1; 213 # remove beginning and ending non text 214 $deps =~ s/^[^a-zA-Z0-9_]*//; 215 $deps =~ s/[^a-zA-Z0-9_]*$//; 216 217 my @deps = split /[^a-zA-Z0-9_]+/, $deps; 218 219 $ifdeps[$iflevel++] = join ':', @deps; 220 221 } elsif (/^endif/) { 222 223 $iflevel-- if ($iflevel); 224 225 # stop on "help" 226 } elsif (/^\s*help\s*$/) { 227 $state = "NONE"; 228 } 229 } 230 close(KIN); 231 232 # read in any configs that were found. 233 foreach $kconfig (@kconfigs) { 234 if (!defined($read_kconfigs{$kconfig})) { 235 $read_kconfigs{$kconfig} = 1; 236 read_kconfig($kconfig); 237 } 238 } 239} 240 241if ($kconfig) { 242 read_kconfig($kconfig); 243} 244 245sub convert_vars { 246 my ($line, %vars) = @_; 247 248 my $process = ""; 249 250 while ($line =~ s/^(.*?)(\$\((.*?)\))//) { 251 my $start = $1; 252 my $variable = $2; 253 my $var = $3; 254 255 if (defined($vars{$var})) { 256 $process .= $start . $vars{$var}; 257 } else { 258 $process .= $start . $variable; 259 } 260 } 261 262 $process .= $line; 263 264 return $process; 265} 266 267# Read all Makefiles to map the configs to the objects 268foreach my $makefile (@makefiles) { 269 270 my $line = ""; 271 my %make_vars; 272 273 open(MIN,$makefile) || die "Can't open $makefile"; 274 while (<MIN>) { 275 # if this line ends with a backslash, continue 276 chomp; 277 if (/^(.*)\\$/) { 278 $line .= $1; 279 next; 280 } 281 282 $line .= $_; 283 $_ = $line; 284 $line = ""; 285 286 my $objs; 287 288 $_ = convert_vars($_, %make_vars); 289 290 # collect objects after obj-$(CONFIG_FOO_BAR) 291 if (/obj-\$\((CONFIG_[^\)]*)\)\s*[+:]?=\s*(.*)/) { 292 $var = $1; 293 $objs = $2; 294 295 # check if variables are set 296 } elsif (/^\s*(\S+)\s*[:]?=\s*(.*\S)/) { 297 $make_vars{$1} = $2; 298 } 299 if (defined($objs)) { 300 foreach my $obj (split /\s+/,$objs) { 301 $obj =~ s/-/_/g; 302 if ($obj =~ /(.*)\.o$/) { 303 # Objects may be enabled by more than one config. 304 # Store configs in an array. 305 my @arr; 306 307 if (defined($objects{$1})) { 308 @arr = @{$objects{$1}}; 309 } 310 311 $arr[$#arr+1] = $var; 312 313 # The objects have a hash mapping to a reference 314 # of an array of configs. 315 $objects{$1} = \@arr; 316 } 317 } 318 } 319 } 320 close(MIN); 321} 322 323my %modules; 324 325if (defined($lsmod_file)) { 326 if ( ! -f $lsmod_file) { 327 die "$lsmod_file not found"; 328 } 329 if ( -x $lsmod_file) { 330 # the file is executable, run it 331 open(LIN, "$lsmod_file|"); 332 } else { 333 # Just read the contents 334 open(LIN, "$lsmod_file"); 335 } 336} else { 337 338 # see what modules are loaded on this system 339 my $lsmod; 340 341 foreach my $dir ( ("/sbin", "/bin", "/usr/sbin", "/usr/bin") ) { 342 if ( -x "$dir/lsmod" ) { 343 $lsmod = "$dir/lsmod"; 344 last; 345 } 346} 347 if (!defined($lsmod)) { 348 # try just the path 349 $lsmod = "lsmod"; 350 } 351 352 open(LIN,"$lsmod|") || die "Can not call lsmod with $lsmod"; 353} 354 355while (<LIN>) { 356 next if (/^Module/); # Skip the first line. 357 if (/^(\S+)/) { 358 $modules{$1} = 1; 359 } 360} 361close (LIN); 362 363# add to the configs hash all configs that are needed to enable 364# a loaded module. 365my %configs; 366foreach my $module (keys(%modules)) { 367 if (defined($objects{$module})) { 368 my @arr = @{$objects{$module}}; 369 foreach my $conf (@arr) { 370 $configs{$conf} = $module; 371 } 372 } else { 373 # Most likely, someone has a custom (binary?) module loaded. 374 print STDERR "$module config not found!!\n"; 375 } 376} 377 378my $valid = "A-Za-z_0-9"; 379my $repeat = 1; 380 381# 382# Note, we do not care about operands (like: &&, ||, !) we want to add any 383# config that is in the depend list of another config. This script does 384# not enable configs that are not already enabled. If we come across a 385# config A that depends on !B, we can still add B to the list of depends 386# to keep on. If A was on in the original config, B would not have been 387# and B would not be turned on by this script. 388# 389sub parse_config_dep_select 390{ 391 my ($p) = @_; 392 393 while ($p =~ /[$valid]/) { 394 395 if ($p =~ /^[^$valid]*([$valid]+)/) { 396 my $conf = "CONFIG_" . $1; 397 398 $p =~ s/^[^$valid]*[$valid]+//; 399 400 if (!defined($configs{$conf})) { 401 # We must make sure that this config has its 402 # dependencies met. 403 $repeat = 1; # do again 404 $configs{$conf} = 1; 405 } 406 } else { 407 die "this should never happen"; 408 } 409 } 410} 411 412while ($repeat) { 413 $repeat = 0; 414 415 foreach my $config (keys %configs) { 416 $config =~ s/^CONFIG_//; 417 418 if (defined($depends{$config})) { 419 # This config has dependencies. Make sure they are also included 420 parse_config_dep_select $depends{$config}; 421 } 422 423 if (defined($prompts{$config}) || !defined($selects{$config})) { 424 next; 425 } 426 427 # config has no prompt and must be selected. 428 parse_config_dep_select $selects{$config}; 429 } 430} 431 432my %setconfigs; 433 434# Finally, read the .config file and turn off any module enabled that 435# we could not find a reason to keep enabled. 436while(<CIN>) { 437 438 if (/CONFIG_IKCONFIG/) { 439 if (/# CONFIG_IKCONFIG is not set/) { 440 # enable IKCONFIG at least as a module 441 print "CONFIG_IKCONFIG=m\n"; 442 # don't ask about PROC 443 print "# CONFIG_IKCONFIG_PROC is not set\n"; 444 } else { 445 print; 446 } 447 next; 448 } 449 450 if (/^(CONFIG.*)=(m|y)/) { 451 if (defined($configs{$1})) { 452 $setconfigs{$1} = $2; 453 } elsif ($2 eq "m") { 454 print "# $1 is not set\n"; 455 next; 456 } 457 } 458 print; 459} 460close(CIN); 461 462# Integrity check, make sure all modules that we want enabled do 463# indeed have their configs set. 464loop: 465foreach my $module (keys(%modules)) { 466 if (defined($objects{$module})) { 467 my @arr = @{$objects{$module}}; 468 foreach my $conf (@arr) { 469 if (defined($setconfigs{$conf})) { 470 next loop; 471 } 472 } 473 print STDERR "module $module did not have configs"; 474 foreach my $conf (@arr) { 475 print STDERR " " , $conf; 476 } 477 print STDERR "\n"; 478 } 479} 480