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Steven Rostedtdcc60242009-04-29 22:52:21 -04001#!/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";
46my $linuxpath = ".";
47
Steven Rostedtcdfc4792009-04-30 14:39:48 -040048my $uname = `uname -r`;
49chomp $uname;
50
51my @searchconfigs = (
52 {
Steven Rostedta9024832009-05-07 11:01:34 -040053 "file" => ".config",
54 "exec" => "cat",
55 },
56 {
Steven Rostedtcdfc4792009-04-30 14:39:48 -040057 "file" => "/proc/config.gz",
58 "exec" => "zcat",
59 },
60 {
Steven Rostedt810b2be2009-04-30 19:30:04 -040061 "file" => "/boot/config-$uname",
62 "exec" => "cat",
63 },
64 {
Steven Rostedtcdfc4792009-04-30 14:39:48 -040065 "file" => "/boot/vmlinuz-$uname",
66 "exec" => "scripts/extract-ikconfig",
67 "test" => "scripts/extract-ikconfig",
68 },
69 {
70 "file" => "vmlinux",
71 "exec" => "scripts/extract-ikconfig",
72 "test" => "scripts/extract-ikconfig",
73 },
74 {
75 "file" => "/lib/modules/$uname/kernel/kernel/configs.ko",
76 "exec" => "scripts/extract-ikconfig",
77 "test" => "scripts/extract-ikconfig",
78 },
79 {
80 "file" => "kernel/configs.ko",
81 "exec" => "scripts/extract-ikconfig",
82 "test" => "scripts/extract-ikconfig",
83 },
84 {
85 "file" => "kernel/configs.o",
86 "exec" => "scripts/extract-ikconfig",
87 "test" => "scripts/extract-ikconfig",
88 },
Steven Rostedtcdfc4792009-04-30 14:39:48 -040089);
90
91sub find_config {
92 foreach my $conf (@searchconfigs) {
93 my $file = $conf->{"file"};
94
95 next if ( ! -f "$file");
96
97 if (defined($conf->{"test"})) {
98 `$conf->{"test"} $conf->{"file"} 2>/dev/null`;
99 next if ($?);
100 }
101
102 my $exec = $conf->{"exec"};
103
104 print STDERR "using config: '$file'\n";
105
106 open(CIN, "$exec $file |") || die "Failed to run $exec $file";
107 return;
108 }
109 die "No config file found";
110}
111
112find_config;
113
Steven Rostedtdcc60242009-04-29 22:52:21 -0400114my @makefiles = `find $linuxpath -name Makefile`;
115my %depends;
116my %selects;
117my %prompts;
118my %objects;
119my $var;
120my $cont = 0;
121
122# Get the top level Kconfig file (passed in)
123my $kconfig = $ARGV[0];
124
125# prevent recursion
126my %read_kconfigs;
127
128sub read_kconfig {
129 my ($kconfig) = @_;
130
131 my $state = "NONE";
132 my $config;
133 my @kconfigs;
134
135 open(KIN, $kconfig) || die "Can't open $kconfig";
136 while (<KIN>) {
137 chomp;
138
139 # collect any Kconfig sources
140 if (/^source\s*"(.*)"/) {
141 $kconfigs[$#kconfigs+1] = $1;
142 }
143
144 # configs found
145 if (/^\s*config\s+(\S+)\s*$/) {
146 $state = "NEW";
147 $config = $1;
148
149 # collect the depends for the config
150 } elsif ($state eq "NEW" && /^\s*depends\s+on\s+(.*)$/) {
151 $state = "DEP";
152 $depends{$config} = $1;
153 } elsif ($state eq "DEP" && /^\s*depends\s+on\s+(.*)$/) {
154 $depends{$config} .= " " . $1;
155
156 # Get the configs that select this config
157 } elsif ($state ne "NONE" && /^\s*select\s+(\S+)/) {
158 if (defined($selects{$1})) {
159 $selects{$1} .= " " . $config;
160 } else {
161 $selects{$1} = $config;
162 }
163
164 # configs without prompts must be selected
165 } elsif ($state ne "NONE" && /^\s*tristate\s\S/) {
166 # note if the config has a prompt
167 $prompt{$config} = 1;
168
169 # stop on "help"
170 } elsif (/^\s*help\s*$/) {
171 $state = "NONE";
172 }
173 }
174 close(KIN);
175
176 # read in any configs that were found.
177 foreach $kconfig (@kconfigs) {
178 if (!defined($read_kconfigs{$kconfig})) {
179 $read_kconfigs{$kconfig} = 1;
180 read_kconfig($kconfig);
181 }
182 }
183}
184
185if ($kconfig) {
186 read_kconfig($kconfig);
187}
188
189# Read all Makefiles to map the configs to the objects
190foreach my $makefile (@makefiles) {
191 chomp $makefile;
192
193 open(MIN,$makefile) || die "Can't open $makefile";
194 while (<MIN>) {
195 my $objs;
196
197 # is this a line after a line with a backslash?
198 if ($cont && /(\S.*)$/) {
199 $objs = $1;
200 }
201 $cont = 0;
202
203 # collect objects after obj-$(CONFIG_FOO_BAR)
204 if (/obj-\$\((CONFIG_[^\)]*)\)\s*[+:]?=\s*(.*)/) {
205 $var = $1;
206 $objs = $2;
207 }
208 if (defined($objs)) {
209 # test if the line ends with a backslash
210 if ($objs =~ m,(.*)\\$,) {
211 $objs = $1;
212 $cont = 1;
213 }
214
215 foreach my $obj (split /\s+/,$objs) {
216 $obj =~ s/-/_/g;
217 if ($obj =~ /(.*)\.o$/) {
218 # Objects may bes enabled by more than one config.
219 # Store configs in an array.
220 my @arr;
221
222 if (defined($objects{$1})) {
223 @arr = @{$objects{$1}};
224 }
225
226 $arr[$#arr+1] = $var;
227
228 # The objects have a hash mapping to a reference
229 # of an array of configs.
230 $objects{$1} = \@arr;
231 }
232 }
233 }
234 }
235 close(MIN);
236}
237
238my %modules;
239
240# see what modules are loaded on this system
241open(LIN,"/sbin/lsmod|") || die "Cant lsmod";
242while (<LIN>) {
243 next if (/^Module/); # Skip the first line.
244 if (/^(\S+)/) {
245 $modules{$1} = 1;
246 }
247}
248close (LIN);
249
250# add to the configs hash all configs that are needed to enable
251# a loaded module.
252my %configs;
253foreach my $module (keys(%modules)) {
254 if (defined($objects{$module})) {
255 @arr = @{$objects{$module}};
256 foreach my $conf (@arr) {
257 $configs{$conf} = $module;
258 }
259 } else {
260 # Most likely, someone has a custom (binary?) module loaded.
261 print STDERR "$module config not found!!\n";
262 }
263}
264
265my $valid = "A-Za-z_0-9";
266my $repeat = 1;
267
268#
269# Note, we do not care about operands (like: &&, ||, !) we want to add any
270# config that is in the depend list of another config. This script does
271# not enable configs that are not already enabled. If we come across a
272# config A that depends on !B, we can still add B to the list of depends
273# to keep on. If A was on in the original config, B would not have been
274# and B would not be turned on by this script.
275#
276sub parse_config_dep_select
277{
278 my ($p) = @_;
279
280 while ($p =~ /[$valid]/) {
281
282 if ($p =~ /^[^$valid]*([$valid]+)/) {
283 my $conf = "CONFIG_" . $1;
284
285 $p =~ s/^[^$valid]*[$valid]+//;
286
287 if (!defined($configs{$conf})) {
288 # We must make sure that this config has its
289 # dependencies met.
290 $repeat = 1; # do again
291 $configs{$conf} = 1;
292 }
293 } else {
294 die "this should never happen";
295 }
296 }
297}
298
299while ($repeat) {
300 $repeat = 0;
301
302 foreach my $config (keys %configs) {
303 $config =~ s/^CONFIG_//;
304
Steven Rostedt74398d32009-04-30 10:17:51 -0400305 if (defined($depends{$config})) {
306 # This config has dependencies. Make sure they are also included
307 parse_config_dep_select $depends{$config};
Steven Rostedtdcc60242009-04-29 22:52:21 -0400308 }
309
Steven Rostedtdcc60242009-04-29 22:52:21 -0400310 if (defined($prompt{$config}) || !defined($selects{$config})) {
311 next;
312 }
313
314 # config has no prompt and must be selected.
315 parse_config_dep_select $selects{$config};
316 }
317}
318
319my %setconfigs;
320
321# Finally, read the .config file and turn off any module enabled that
322# we could not find a reason to keep enabled.
323while(<CIN>) {
Steven Rostedt744ffcb2009-04-30 12:15:10 -0400324
325 if (/CONFIG_IKCONFIG/) {
326 if (/# CONFIG_IKCONFIG is not set/) {
327 # enable IKCONFIG at least as a module
328 print "CONFIG_IKCONFIG=m\n";
329 # don't ask about PROC
Steven Rostedtd08ca272009-04-30 19:24:00 -0400330 print "# CONFIG_IKCONFIG_PROC is not set\n";
Steven Rostedtdcc60242009-04-29 22:52:21 -0400331 } else {
Steven Rostedt744ffcb2009-04-30 12:15:10 -0400332 print;
Steven Rostedtdcc60242009-04-29 22:52:21 -0400333 }
Steven Rostedt744ffcb2009-04-30 12:15:10 -0400334 next;
335 }
336
337 if (/^(CONFIG.*)=(m|y)/) {
338 if (defined($configs{$1})) {
339 $setconfigs{$1} = $2;
Steven Rostedt744ffcb2009-04-30 12:15:10 -0400340 } elsif ($2 eq "m") {
341 print "# $1 is not set\n";
Steven Rostedtd08ca272009-04-30 19:24:00 -0400342 next;
Steven Rostedt744ffcb2009-04-30 12:15:10 -0400343 }
Steven Rostedt744ffcb2009-04-30 12:15:10 -0400344 }
Steven Rostedtd08ca272009-04-30 19:24:00 -0400345 print;
Steven Rostedtdcc60242009-04-29 22:52:21 -0400346}
347close(CIN);
348
349# Integrity check, make sure all modules that we want enabled do
350# indeed have their configs set.
351loop:
352foreach my $module (keys(%modules)) {
353 if (defined($objects{$module})) {
354 my @arr = @{$objects{$module}};
355 foreach my $conf (@arr) {
356 if (defined($setconfigs{$conf})) {
357 next loop;
358 }
359 }
360 print STDERR "module $module did not have configs";
361 foreach my $conf (@arr) {
362 print STDERR " " , $conf;
363 }
364 print STDERR "\n";
365 }
366}