2 # SPDX-License-Identifier: GPL-2.0-only
4 # Copyright 2005-2009 - Steven Rostedt
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 configuration 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
49 # set the environment variable LOCALMODCONFIG_DEBUG to get
52 $debugprint = 1 if (defined($ENV{LOCALMODCONFIG_DEBUG
}));
55 return if (!$debugprint);
59 my $uname = `uname -r`;
68 "file" => "/proc/config.gz",
72 "file" => "/boot/config-$uname",
76 "file" => "/boot/vmlinuz-$uname",
77 "exec" => "scripts/extract-ikconfig",
78 "test" => "scripts/extract-ikconfig",
82 "exec" => "scripts/extract-ikconfig",
83 "test" => "scripts/extract-ikconfig",
86 "file" => "/lib/modules/$uname/kernel/kernel/configs.ko",
87 "exec" => "scripts/extract-ikconfig",
88 "test" => "scripts/extract-ikconfig",
91 "file" => "kernel/configs.ko",
92 "exec" => "scripts/extract-ikconfig",
93 "test" => "scripts/extract-ikconfig",
96 "file" => "kernel/configs.o",
97 "exec" => "scripts/extract-ikconfig",
98 "test" => "scripts/extract-ikconfig",
103 foreach my $conf (@searchconfigs) {
104 my $file = $conf->{"file"};
106 next if ( ! -f
"$file");
108 if (defined($conf->{"test"})) {
109 `$conf->{"test"} $conf->{"file"} 2>/dev/null`;
113 my $exec = $conf->{"exec"};
115 print STDERR
"using config: '$file'\n";
117 open(my $infile, '-|', "$exec $file") || die "Failed to run $exec $file";
122 die "No config file found";
125 my @config_file = read_config
;
128 my $localmodconfig = 0;
129 my $localyesconfig = 0;
131 GetOptions
("localmodconfig" => \
$localmodconfig,
132 "localyesconfig" => \
$localyesconfig);
134 # Get the build source and top level Kconfig file (passed in)
135 my $ksource = ($ARGV[0] ?
$ARGV[0] : '.');
136 my $kconfig = $ARGV[1];
137 my $lsmod_file = $ENV{'LSMOD'};
139 my @makefiles = `find $ksource -name Makefile -or -name Kbuild 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 $source";
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
($kconfig);
202 if (/^\s*(menu)?config\s+(\S+)\s*$/) {
205 $config2kfile{"CONFIG_$config"} = $kconfig;
207 # Add depends for 'if' nesting
208 for (my $i = 0; $i < $iflevel; $i++) {
210 $depends{$config} .= " " . $ifdeps[$i];
212 $depends{$config} = $ifdeps[$i];
217 # collect the depends for the config
218 } elsif ($state eq "NEW" && /^\s*depends\s+on\s+(.*)$/) {
220 $depends{$config} = $1;
221 } elsif ($state eq "DEP" && /^\s*depends\s+on\s+(.*)$/) {
222 $depends{$config} .= " " . $1;
223 } elsif ($state eq "DEP" && /^\s*def(_(bool|tristate)|ault)\s+(\S.*)$/) {
225 if ($dep !~ /^\s*(y|m|n)\s*$/) {
226 $dep =~ s/.*\sif\s+//;
227 $depends{$config} .= " " . $dep;
228 dprint
"Added default depends $dep to $config\n";
231 # Get the configs that select this config
232 } elsif ($state ne "NONE" && /^\s*select\s+(\S+)/) {
234 if (defined($selects{$conf})) {
235 $selects{$conf} .= " " . $config;
237 $selects{$conf} = $config;
240 # configs without prompts must be selected
241 } elsif ($state ne "NONE" && /^\s*(tristate\s+\S|prompt\b)/) {
242 # note if the config has a prompt
243 $prompts{$config} = 1;
245 # Check for if statements
246 } elsif (/^if\s+(.*\S)\s*$/) {
248 # remove beginning and ending non text
249 $deps =~ s/^[^a-zA-Z0-9_]*//;
250 $deps =~ s/[^a-zA-Z0-9_]*$//;
252 my @deps = split /[^a-zA-Z0-9_]+/, $deps;
254 $ifdeps[$iflevel++] = join ':', @deps;
258 $iflevel-- if ($iflevel);
260 # stop on "help" and keywords that end a menu entry
261 } elsif (/^\s*(---)?help(---)?\s*$/ || /^(comment|choice|menu)\b/) {
269 read_kconfig
($kconfig);
272 # Makefiles can use variables to define their dependencies
274 my ($line, %vars) = @_;
278 while ($line =~ s/^(.*?)(\$\((.*?)\))//) {
283 if (defined($vars{$var})) {
284 $process .= $start . $vars{$var};
286 $process .= $start . $variable;
295 # Read all Makefiles to map the configs to the objects
296 foreach my $makefile (@makefiles) {
301 open(my $infile, '<', $makefile) || die "Can't open $makefile";
303 # if this line ends with a backslash, continue
316 # Convert variables in a line (could define configs)
317 $_ = convert_vars
($_, %make_vars);
319 # collect objects after obj-$(CONFIG_FOO_BAR)
320 if (/obj-\$[({](CONFIG_[^})]*)[)}]\s*[+:]?=\s*(.*)/) {
324 # check if variables are set
325 } elsif (/^\s*(\S+)\s*[:]?=\s*(.*\S)/) {
328 if (defined($objs)) {
329 foreach my $obj (split /\s+/,$objs) {
331 if ($obj =~ /(.*)\.o$/) {
332 # Objects may be enabled by more than one config.
333 # Store configs in an array.
336 if (defined($objects{$1})) {
337 @arr = @
{$objects{$1}};
340 $arr[$#arr+1] = $var;
342 # The objects have a hash mapping to a reference
343 # of an array of configs.
344 $objects{$1} = \
@arr;
355 if (defined($lsmod_file)) {
356 if ( ! -f
$lsmod_file) {
357 if ( -f
$ENV{'objtree'}."/".$lsmod_file) {
358 $lsmod_file = $ENV{'objtree'}."/".$lsmod_file;
360 die "$lsmod_file not found";
364 my $otype = ( -x
$lsmod_file) ?
'-|' : '<';
365 open($linfile, $otype, $lsmod_file);
369 # see what modules are loaded on this system
372 foreach my $dir ( ("/sbin", "/bin", "/usr/sbin", "/usr/bin") ) {
373 if ( -x
"$dir/lsmod" ) {
374 $lsmod = "$dir/lsmod";
378 if (!defined($lsmod)) {
383 open($linfile, '-|', $lsmod) || die "Can not call lsmod with $lsmod";
387 next if (/^Module/); # Skip the first line.
394 # add to the configs hash all configs that are needed to enable
395 # a loaded module. This is a direct obj-${CONFIG_FOO} += bar.o
396 # where we know we need bar.o so we add FOO to the list.
398 foreach my $module (keys(%modules)) {
399 if (defined($objects{$module})) {
400 my @arr = @
{$objects{$module}};
401 foreach my $conf (@arr) {
402 $configs{$conf} = $module;
403 dprint
"$conf added by direct ($module)\n";
407 if (defined($depends{$c})) {
408 dprint
" deps = $depends{$c}\n";
415 # Most likely, someone has a custom (binary?) module loaded.
416 print STDERR
"$module config not found!!\n";
420 # Read the current config, and see what is enabled. We want to
421 # ignore configs that we would not enable anyway.
424 my $valid = "A-Za-z_0-9";
426 foreach my $line (@config_file) {
429 if (/(CONFIG_[$valid]*)=(m|y)/) {
430 $orig_configs{$1} = $2;
439 # Note, we do not care about operands (like: &&, ||, !) we want to add any
440 # config that is in the depend list of another config. This script does
441 # not enable configs that are not already enabled. If we come across a
442 # config A that depends on !B, we can still add B to the list of depends
443 # to keep on. If A was on in the original config, B would not have been
444 # and B would not be turned on by this script.
446 sub parse_config_depends
450 while ($p =~ /[$valid]/) {
452 if ($p =~ /^[^$valid]*([$valid]+)/) {
453 my $conf = "CONFIG_" . $1;
455 $p =~ s/^[^$valid]*[$valid]+//;
457 # We only need to process if the depend config is a module
458 if (!defined($orig_configs{$conf}) || $orig_configs{$conf} eq "y") {
462 if (!defined($configs{$conf})) {
463 # We must make sure that this config has its
465 $repeat = 1; # do again
466 dprint
"$conf selected by depend $depconfig\n";
470 die "this should never happen";
475 # Select is treated a bit differently than depends. We call this
476 # when a config has no prompt and requires another config to be
477 # selected. We use to just select all configs that selected this
478 # config, but found that that can balloon into enabling hundreds
479 # of configs that we do not care about.
481 # The idea is we look at all the configs that select it. If one
482 # is already in our list of configs to enable, then there's nothing
483 # else to do. If there isn't, we pick the first config that was
484 # enabled in the original config and use that.
485 sub parse_config_selects
487 my ($config, $p) = @_;
491 while ($p =~ /[$valid]/) {
493 if ($p =~ /^[^$valid]*([$valid]+)/) {
494 my $conf = "CONFIG_" . $1;
496 $p =~ s/^[^$valid]*[$valid]+//;
498 # Make sure that this config exists in the current .config file
499 if (!defined($orig_configs{$conf})) {
500 dprint
"$conf not set for $config select\n";
504 # Check if something other than a module selects this config
505 if (defined($orig_configs{$conf}) && $orig_configs{$conf} ne "m") {
506 dprint
"$conf (non module) selects config, we are good\n";
507 # we are good with this
510 if (defined($configs{$conf})) {
511 dprint
"$conf selects $config so we are good\n";
512 # A set config selects this config, we are good
515 # Set this config to be selected
516 if (!defined($next_config)) {
517 $next_config = $conf;
520 die "this should never happen";
524 # If no possible config selected this, then something happened.
525 if (!defined($next_config)) {
526 print STDERR
"WARNING: $config is required, but nothing in the\n";
527 print STDERR
" current config selects it.\n";
531 # If we are here, then we found no config that is set and
532 # selects this config. Repeat.
534 # Make this config need to be selected
535 $configs{$next_config} = 1;
536 dprint
"$next_config selected by select $config\n";
541 # loop through all configs, select their dependencies.
549 foreach my $config (keys %configs) {
551 # If this config is not a module, we do not need to process it
552 if (defined($orig_configs{$config}) && $orig_configs{$config} ne "m") {
556 $config =~ s/^CONFIG_//;
557 $depconfig = $config;
559 if (defined($depends{$config})) {
560 # This config has dependencies. Make sure they are also included
561 parse_config_depends
$depends{$config};
564 # If the config has no prompt, then we need to check if a config
565 # that is enabled selected it. Or if we need to enable one.
566 if (!defined($prompts{$config}) && defined($selects{$config})) {
567 $process_selects{$config} = 1;
575 foreach my $config (keys %process_selects) {
576 $config =~ s/^CONFIG_//;
578 dprint
"Process select $config\n";
580 # config has no prompt and must be selected.
581 parse_config_selects
$config, $selects{$config};
586 # Get the first set of configs and their dependencies.
591 # Now we need to see if we have to check selects;
596 my @preserved_kconfigs;
597 if (defined($ENV{'LMC_KEEP'})) {
598 @preserved_kconfigs = split(/:/,$ENV{LMC_KEEP
});
601 sub in_preserved_kconfigs
{
602 my $kconfig = $config2kfile{$_[0]};
603 if (!defined($kconfig)) {
606 foreach my $excl (@preserved_kconfigs) {
607 if($kconfig =~ /^$excl/) {
614 # Finally, read the .config file and turn off any module enabled that
615 # we could not find a reason to keep enabled.
616 foreach my $line (@config_file) {
619 if (/CONFIG_IKCONFIG/) {
620 if (/# CONFIG_IKCONFIG is not set/) {
621 # enable IKCONFIG at least as a module
622 print "CONFIG_IKCONFIG=m\n";
623 # don't ask about PROC
624 print "# CONFIG_IKCONFIG_PROC is not set\n";
631 if (/CONFIG_MODULE_SIG_KEY="(.+)"/) {
633 my $default_cert = "certs/signing_key.pem";
635 # Check that the logic in this script still matches the one in Kconfig
636 if (!defined($depends{"MODULE_SIG_KEY"}) ||
637 $depends{"MODULE_SIG_KEY"} !~ /"\Q$default_cert\E"/) {
638 print STDERR
"WARNING: MODULE_SIG_KEY assertion failure, ",
639 "update needed to ", __FILE__
, " line ", __LINE__
, "\n";
641 } elsif ($orig_cert ne $default_cert && ! -f
$orig_cert) {
642 print STDERR
"Module signature verification enabled but ",
643 "module signing key \"$orig_cert\" not found. Resetting ",
644 "signing key to default value.\n";
645 print "CONFIG_MODULE_SIG_KEY=\"$default_cert\"\n";
652 if (/CONFIG_SYSTEM_TRUSTED_KEYS="(.+)"/) {
655 if (! -f
$orig_keys) {
656 print STDERR
"System keyring enabled but keys \"$orig_keys\" ",
657 "not found. Resetting keys to default value.\n";
658 print "CONFIG_SYSTEM_TRUSTED_KEYS=\"\"\n";
665 if (/^(CONFIG.*)=(m|y)/) {
666 if (in_preserved_kconfigs
($1)) {
667 dprint
"Preserve config $1";
671 if (defined($configs{$1})) {
672 if ($localyesconfig) {
673 $setconfigs{$1} = 'y';
677 $setconfigs{$1} = $2;
679 } elsif ($2 eq "m") {
680 print "# $1 is not set\n";
687 # Integrity check, make sure all modules that we want enabled do
688 # indeed have their configs set.
690 foreach my $module (keys(%modules)) {
691 if (defined($objects{$module})) {
692 my @arr = @
{$objects{$module}};
693 foreach my $conf (@arr) {
694 if (defined($setconfigs{$conf})) {
698 print STDERR
"module $module did not have configs";
699 foreach my $conf (@arr) {
700 print STDERR
" " , $conf;