3 # Copywrite 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
45 my $config = ".config";
48 open(CIN,$config) || die "Can't open current config file: $config";
49 my @makefiles = `find $linuxpath -name Makefile`;
57 # Get the top level Kconfig file (passed in)
58 my $kconfig = $ARGV[0];
70 open(KIN, $kconfig) || die "Can't open $kconfig";
74 # collect any Kconfig sources
75 if (/^source\s*"(.*)"/) {
76 $kconfigs[$#kconfigs+1] = $1;
80 if (/^\s*config\s+(\S+)\s*$/) {
84 # collect the depends for the config
85 } elsif ($state eq "NEW" && /^\s*depends\s+on\s+(.*)$/) {
87 $depends{$config} = $1;
88 } elsif ($state eq "DEP" && /^\s*depends\s+on\s+(.*)$/) {
89 $depends{$config} .= " " . $1;
91 # Get the configs that select this config
92 } elsif ($state ne "NONE" && /^\s*select\s+(\S+)/) {
93 if (defined($selects{$1})) {
94 $selects{$1} .= " " . $config;
96 $selects{$1} = $config;
99 # configs without prompts must be selected
100 } elsif ($state ne "NONE" && /^\s*tristate\s\S/) {
101 # note if the config has a prompt
102 $prompt{$config} = 1;
105 } elsif (/^\s*help\s*$/) {
111 # read in any configs that were found.
112 foreach $kconfig (@kconfigs) {
113 if (!defined($read_kconfigs{$kconfig})) {
114 $read_kconfigs{$kconfig} = 1;
115 read_kconfig($kconfig);
121 read_kconfig($kconfig);
124 # Read all Makefiles to map the configs to the objects
125 foreach my $makefile (@makefiles) {
128 open(MIN,$makefile) || die "Can't open $makefile";
132 # is this a line after a line with a backslash?
133 if ($cont && /(\S.*)$/) {
138 # collect objects after obj-$(CONFIG_FOO_BAR)
139 if (/obj-\$\((CONFIG_[^\)]*)\)\s*[+:]?=\s*(.*)/) {
143 if (defined($objs)) {
144 # test if the line ends with a backslash
145 if ($objs =~ m,(.*)\\$,) {
150 foreach my $obj (split /\s+/,$objs) {
152 if ($obj =~ /(.*)\.o$/) {
153 # Objects may bes enabled by more than one config.
154 # Store configs in an array.
157 if (defined($objects{$1})) {
158 @arr = @{$objects{$1}};
161 $arr[$#arr+1] = $var;
163 # The objects have a hash mapping to a reference
164 # of an array of configs.
165 $objects{$1} = \@arr;
175 # see what modules are loaded on this system
176 open(LIN,"/sbin/lsmod|") || die "Cant lsmod";
178 next if (/^Module/); # Skip the first line.
185 # add to the configs hash all configs that are needed to enable
188 foreach my $module (keys(%modules)) {
189 if (defined($objects{$module})) {
190 @arr = @{$objects{$module}};
191 foreach my $conf (@arr) {
192 $configs{$conf} = $module;
195 # Most likely, someone has a custom (binary?) module loaded.
196 print STDERR "$module config not found!!\n";
200 my $valid = "A-Za-z_0-9";
204 # Note, we do not care about operands (like: &&, ||, !) we want to add any
205 # config that is in the depend list of another config. This script does
206 # not enable configs that are not already enabled. If we come across a
207 # config A that depends on !B, we can still add B to the list of depends
208 # to keep on. If A was on in the original config, B would not have been
209 # and B would not be turned on by this script.
211 sub parse_config_dep_select
215 while ($p =~ /[$valid]/) {
217 if ($p =~ /^[^$valid]*([$valid]+)/) {
218 my $conf = "CONFIG_" . $1;
220 $p =~ s/^[^$valid]*[$valid]+//;
222 if (!defined($configs{$conf})) {
223 # We must make sure that this config has its
225 $repeat = 1; # do again
229 die "this should never happen";
237 foreach my $config (keys %configs) {
238 $config =~ s/^CONFIG_//;
240 if (!defined($depends{$config})) {
244 # This config has dependencies. Make sure they are also included
245 parse_config_dep_select $depends{$config};
247 if (defined($prompt{$config}) || !defined($selects{$config})) {
251 # config has no prompt and must be selected.
252 parse_config_dep_select $selects{$config};
258 # Finally, read the .config file and turn off any module enabled that
259 # we could not find a reason to keep enabled.
261 if (/^(CONFIG.*)=m/) {
262 if (defined($configs{$1})) {
266 print "# $1 is not set\n";
274 # Integrity check, make sure all modules that we want enabled do
275 # indeed have their configs set.
277 foreach my $module (keys(%modules)) {
278 if (defined($objects{$module})) {
279 my @arr = @{$objects{$module}};
280 foreach my $conf (@arr) {
281 if (defined($setconfigs{$conf})) {
285 print STDERR "module $module did not have configs";
286 foreach my $conf (@arr) {
287 print STDERR " " , $conf;