3 # Copyright 2005-2009 - Steven Rostedt
4 # Licensed under the terms of the GNU GPL License version 2
6 # It's simple enough to figure out how this works.
7 # If not, then you can ask me at stripconfig@goodmis.org
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
16 # It gives you the ability to turn off all the modules that are
17 # not loaded on your system.
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
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"
33 # Now your kernel is ready to be built with only the modules that
36 # Here's what I did with my Debian distribution.
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
48 # set the environment variable LOCALMODCONFIG_DEBUG to get
51 $debugprint = 1 if (defined($ENV{LOCALMODCONFIG_DEBUG
}));
54 return if (!$debugprint);
58 my $config = ".config";
60 my $uname = `uname -r`;
69 "file" => "/proc/config.gz",
73 "file" => "/boot/config-$uname",
77 "file" => "/boot/vmlinuz-$uname",
78 "exec" => "scripts/extract-ikconfig",
79 "test" => "scripts/extract-ikconfig",
83 "exec" => "scripts/extract-ikconfig",
84 "test" => "scripts/extract-ikconfig",
87 "file" => "/lib/modules/$uname/kernel/kernel/configs.ko",
88 "exec" => "scripts/extract-ikconfig",
89 "test" => "scripts/extract-ikconfig",
92 "file" => "kernel/configs.ko",
93 "exec" => "scripts/extract-ikconfig",
94 "test" => "scripts/extract-ikconfig",
97 "file" => "kernel/configs.o",
98 "exec" => "scripts/extract-ikconfig",
99 "test" => "scripts/extract-ikconfig",
104 foreach my $conf (@searchconfigs) {
105 my $file = $conf->{"file"};
107 next if ( ! -f
"$file");
109 if (defined($conf->{"test"})) {
110 `$conf->{"test"} $conf->{"file"} 2>/dev/null`;
114 my $exec = $conf->{"exec"};
116 print STDERR
"using config: '$file'\n";
118 open(my $infile, '-|', "$exec $file") || die "Failed to run $exec $file";
123 die "No config file found";
126 my @config_file = read_config
;
129 my $localmodconfig = 0;
130 my $localyesconfig = 0;
132 GetOptions
("localmodconfig" => \
$localmodconfig,
133 "localyesconfig" => \
$localyesconfig);
135 # Get the build source and top level Kconfig file (passed in)
136 my $ksource = ($ARGV[0] ?
$ARGV[0] : '.');
137 my $kconfig = $ARGV[1];
138 my $lsmod_file = $ENV{'LSMOD'};
140 my @makefiles = `find $ksource -name Makefile 2>/dev/null`;
163 my $source = "$ksource/$kconfig";
164 my $last_source = "";
166 # Check for any environment variables used
167 while ($source =~ /\$(\w+)/ && $last_source ne $source) {
169 $last_source = $source;
170 $source =~ s/\$$env/$ENV{$env}/;
173 open(my $kinfile, '<', $source) || die "Can't open $kconfig";
177 # Make sure that lines ending with \ continue
179 $_ = $line . " " . $_;
190 # collect any Kconfig sources
191 if (/^source\s*"(.*)"/) {
193 # prevent reading twice.
194 if (!defined($read_kconfigs{$kconfig})) {
195 $read_kconfigs{$kconfig} = 1;
196 read_kconfig
($kconfig);
202 if (/^\s*(menu)?config\s+(\S+)\s*$/) {
206 # Add depends for 'if' nesting
207 for (my $i = 0; $i < $iflevel; $i++) {
209 $depends{$config} .= " " . $ifdeps[$i];
211 $depends{$config} = $ifdeps[$i];
216 # collect the depends for the config
217 } elsif ($state eq "NEW" && /^\s*depends\s+on\s+(.*)$/) {
219 $depends{$config} = $1;
220 } elsif ($state eq "DEP" && /^\s*depends\s+on\s+(.*)$/) {
221 $depends{$config} .= " " . $1;
222 } elsif ($state eq "DEP" && /^\s*def(_(bool|tristate)|ault)\s+(\S.*)$/) {
224 if ($dep !~ /^\s*(y|m|n)\s*$/) {
225 $dep =~ s/.*\sif\s+//;
226 $depends{$config} .= " " . $dep;
227 dprint
"Added default depends $dep to $config\n";
230 # Get the configs that select this config
231 } elsif ($state ne "NONE" && /^\s*select\s+(\S+)/) {
233 if (defined($selects{$conf})) {
234 $selects{$conf} .= " " . $config;
236 $selects{$conf} = $config;
239 # configs without prompts must be selected
240 } elsif ($state ne "NONE" && /^\s*tristate\s\S/) {
241 # note if the config has a prompt
242 $prompts{$config} = 1;
244 # Check for if statements
245 } elsif (/^if\s+(.*\S)\s*$/) {
247 # remove beginning and ending non text
248 $deps =~ s/^[^a-zA-Z0-9_]*//;
249 $deps =~ s/[^a-zA-Z0-9_]*$//;
251 my @deps = split /[^a-zA-Z0-9_]+/, $deps;
253 $ifdeps[$iflevel++] = join ':', @deps;
257 $iflevel-- if ($iflevel);
260 } elsif (/^\s*help\s*$/) {
268 read_kconfig
($kconfig);
271 # Makefiles can use variables to define their dependencies
273 my ($line, %vars) = @_;
277 while ($line =~ s/^(.*?)(\$\((.*?)\))//) {
282 if (defined($vars{$var})) {
283 $process .= $start . $vars{$var};
285 $process .= $start . $variable;
294 # Read all Makefiles to map the configs to the objects
295 foreach my $makefile (@makefiles) {
300 open(my $infile, '<', $makefile) || die "Can't open $makefile";
302 # if this line ends with a backslash, continue
315 # Convert variables in a line (could define configs)
316 $_ = convert_vars
($_, %make_vars);
318 # collect objects after obj-$(CONFIG_FOO_BAR)
319 if (/obj-\$\((CONFIG_[^\)]*)\)\s*[+:]?=\s*(.*)/) {
323 # check if variables are set
324 } elsif (/^\s*(\S+)\s*[:]?=\s*(.*\S)/) {
327 if (defined($objs)) {
328 foreach my $obj (split /\s+/,$objs) {
330 if ($obj =~ /(.*)\.o$/) {
331 # Objects may be enabled by more than one config.
332 # Store configs in an array.
335 if (defined($objects{$1})) {
336 @arr = @
{$objects{$1}};
339 $arr[$#arr+1] = $var;
341 # The objects have a hash mapping to a reference
342 # of an array of configs.
343 $objects{$1} = \
@arr;
354 if (defined($lsmod_file)) {
355 if ( ! -f
$lsmod_file) {
356 if ( -f
$ENV{'objtree'}."/".$lsmod_file) {
357 $lsmod_file = $ENV{'objtree'}."/".$lsmod_file;
359 die "$lsmod_file not found";
363 my $otype = ( -x
$lsmod_file) ?
'-|' : '<';
364 open($linfile, $otype, $lsmod_file);
368 # see what modules are loaded on this system
371 foreach my $dir ( ("/sbin", "/bin", "/usr/sbin", "/usr/bin") ) {
372 if ( -x
"$dir/lsmod" ) {
373 $lsmod = "$dir/lsmod";
377 if (!defined($lsmod)) {
382 open($linfile, '-|', $lsmod) || die "Can not call lsmod with $lsmod";
386 next if (/^Module/); # Skip the first line.
393 # add to the configs hash all configs that are needed to enable
394 # a loaded module. This is a direct obj-${CONFIG_FOO} += bar.o
395 # where we know we need bar.o so we add FOO to the list.
397 foreach my $module (keys(%modules)) {
398 if (defined($objects{$module})) {
399 my @arr = @
{$objects{$module}};
400 foreach my $conf (@arr) {
401 $configs{$conf} = $module;
402 dprint
"$conf added by direct ($module)\n";
406 if (defined($depends{$c})) {
407 dprint
" deps = $depends{$c}\n";
414 # Most likely, someone has a custom (binary?) module loaded.
415 print STDERR
"$module config not found!!\n";
419 # Read the current config, and see what is enabled. We want to
420 # ignore configs that we would not enable anyway.
423 my $valid = "A-Za-z_0-9";
425 foreach my $line (@config_file) {
428 if (/(CONFIG_[$valid]*)=(m|y)/) {
429 $orig_configs{$1} = $2;
438 # Note, we do not care about operands (like: &&, ||, !) we want to add any
439 # config that is in the depend list of another config. This script does
440 # not enable configs that are not already enabled. If we come across a
441 # config A that depends on !B, we can still add B to the list of depends
442 # to keep on. If A was on in the original config, B would not have been
443 # and B would not be turned on by this script.
445 sub parse_config_depends
449 while ($p =~ /[$valid]/) {
451 if ($p =~ /^[^$valid]*([$valid]+)/) {
452 my $conf = "CONFIG_" . $1;
454 $p =~ s/^[^$valid]*[$valid]+//;
456 # We only need to process if the depend config is a module
457 if (!defined($orig_configs{$conf}) || !$orig_configs{conf
} eq "m") {
461 if (!defined($configs{$conf})) {
462 # We must make sure that this config has its
464 $repeat = 1; # do again
465 dprint
"$conf selected by depend $depconfig\n";
469 die "this should never happen";
474 # Select is treated a bit differently than depends. We call this
475 # when a config has no prompt and requires another config to be
476 # selected. We use to just select all configs that selected this
477 # config, but found that that can balloon into enabling hundreds
478 # of configs that we do not care about.
480 # The idea is we look at all the configs that select it. If one
481 # is already in our list of configs to enable, then there's nothing
482 # else to do. If there isn't, we pick the first config that was
483 # enabled in the orignal config and use that.
484 sub parse_config_selects
486 my ($config, $p) = @_;
490 while ($p =~ /[$valid]/) {
492 if ($p =~ /^[^$valid]*([$valid]+)/) {
493 my $conf = "CONFIG_" . $1;
495 $p =~ s/^[^$valid]*[$valid]+//;
497 # Make sure that this config exists in the current .config file
498 if (!defined($orig_configs{$conf})) {
499 dprint
"$conf not set for $config select\n";
503 # Check if something other than a module selects this config
504 if (defined($orig_configs{$conf}) && $orig_configs{$conf} ne "m") {
505 dprint
"$conf (non module) selects config, we are good\n";
506 # we are good with this
509 if (defined($configs{$conf})) {
510 dprint
"$conf selects $config so we are good\n";
511 # A set config selects this config, we are good
514 # Set this config to be selected
515 if (!defined($next_config)) {
516 $next_config = $conf;
519 die "this should never happen";
523 # If no possible config selected this, then something happened.
524 if (!defined($next_config)) {
525 print STDERR
"WARNING: $config is required, but nothing in the\n";
526 print STDERR
" current config selects it.\n";
530 # If we are here, then we found no config that is set and
531 # selects this config. Repeat.
533 # Make this config need to be selected
534 $configs{$next_config} = 1;
535 dprint
"$next_config selected by select $config\n";
540 # loop through all configs, select their dependencies.
548 foreach my $config (keys %configs) {
550 # If this config is not a module, we do not need to process it
551 if (defined($orig_configs{$config}) && $orig_configs{$config} ne "m") {
555 $config =~ s/^CONFIG_//;
556 $depconfig = $config;
558 if (defined($depends{$config})) {
559 # This config has dependencies. Make sure they are also included
560 parse_config_depends
$depends{$config};
563 # If the config has no prompt, then we need to check if a config
564 # that is enabled selected it. Or if we need to enable one.
565 if (!defined($prompts{$config}) && defined($selects{$config})) {
566 $process_selects{$config} = 1;
574 foreach my $config (keys %process_selects) {
575 $config =~ s/^CONFIG_//;
577 dprint
"Process select $config\n";
579 # config has no prompt and must be selected.
580 parse_config_selects
$config, $selects{$config};
585 # Get the first set of configs and their dependencies.
590 # Now we need to see if we have to check selects;
596 # Finally, read the .config file and turn off any module enabled that
597 # we could not find a reason to keep enabled.
598 foreach my $line (@config_file) {
601 if (/CONFIG_IKCONFIG/) {
602 if (/# CONFIG_IKCONFIG is not set/) {
603 # enable IKCONFIG at least as a module
604 print "CONFIG_IKCONFIG=m\n";
605 # don't ask about PROC
606 print "# CONFIG_IKCONFIG_PROC is not set\n";
613 if (/^(CONFIG.*)=(m|y)/) {
614 if (defined($configs{$1})) {
615 if ($localyesconfig) {
616 $setconfigs{$1} = 'y';
620 $setconfigs{$1} = $2;
622 } elsif ($2 eq "m") {
623 print "# $1 is not set\n";
630 # Integrity check, make sure all modules that we want enabled do
631 # indeed have their configs set.
633 foreach my $module (keys(%modules)) {
634 if (defined($objects{$module})) {
635 my @arr = @
{$objects{$module}};
636 foreach my $conf (@arr) {
637 if (defined($setconfigs{$conf})) {
641 print STDERR
"module $module did not have configs";
642 foreach my $conf (@arr) {
643 print STDERR
" " , $conf;