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