Root/scripts/kconfig/streamline_config.pl

1#!/usr/bin/perl -w
2#
3# Copyright 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#
45use strict;
46
47my $config = ".config";
48
49my $uname = `uname -r`;
50chomp $uname;
51
52my @searchconfigs = (
53    {
54        "file" => ".config",
55        "exec" => "cat",
56    },
57    {
58        "file" => "/proc/config.gz",
59        "exec" => "zcat",
60    },
61    {
62        "file" => "/boot/config-$uname",
63        "exec" => "cat",
64    },
65    {
66        "file" => "/boot/vmlinuz-$uname",
67        "exec" => "scripts/extract-ikconfig",
68        "test" => "scripts/extract-ikconfig",
69    },
70    {
71        "file" => "vmlinux",
72        "exec" => "scripts/extract-ikconfig",
73        "test" => "scripts/extract-ikconfig",
74    },
75    {
76        "file" => "/lib/modules/$uname/kernel/kernel/configs.ko",
77        "exec" => "scripts/extract-ikconfig",
78        "test" => "scripts/extract-ikconfig",
79    },
80    {
81        "file" => "kernel/configs.ko",
82        "exec" => "scripts/extract-ikconfig",
83        "test" => "scripts/extract-ikconfig",
84    },
85    {
86        "file" => "kernel/configs.o",
87        "exec" => "scripts/extract-ikconfig",
88        "test" => "scripts/extract-ikconfig",
89    },
90);
91
92sub find_config {
93    foreach my $conf (@searchconfigs) {
94    my $file = $conf->{"file"};
95
96    next if ( ! -f "$file");
97
98    if (defined($conf->{"test"})) {
99        `$conf->{"test"} $conf->{"file"} 2>/dev/null`;
100        next if ($?);
101    }
102
103    my $exec = $conf->{"exec"};
104
105    print STDERR "using config: '$file'\n";
106
107    open(CIN, "$exec $file |") || die "Failed to run $exec $file";
108    return;
109    }
110    die "No config file found";
111}
112
113find_config;
114
115# Get the build source and top level Kconfig file (passed in)
116my $ksource = $ARGV[0];
117my $kconfig = $ARGV[1];
118my $lsmod_file = $ARGV[2];
119
120my @makefiles = `find $ksource -name Makefile 2>/dev/null`;
121chomp @makefiles;
122
123my %depends;
124my %selects;
125my %prompts;
126my %objects;
127my $var;
128my $iflevel = 0;
129my @ifdeps;
130
131# prevent recursion
132my %read_kconfigs;
133
134sub read_kconfig {
135    my ($kconfig) = @_;
136
137    my $state = "NONE";
138    my $config;
139    my @kconfigs;
140
141    my $cont = 0;
142    my $line;
143
144    my $source = "$ksource/$kconfig";
145    my $last_source = "";
146
147    # Check for any environment variables used
148    while ($source =~ /\$(\w+)/ && $last_source ne $source) {
149    my $env = $1;
150    $last_source = $source;
151    $source =~ s/\$$env/$ENV{$env}/;
152    }
153
154    open(KIN, "$source") || die "Can't open $kconfig";
155    while (<KIN>) {
156    chomp;
157
158    # Make sure that lines ending with \ continue
159    if ($cont) {
160        $_ = $line . " " . $_;
161    }
162
163    if (s/\\$//) {
164        $cont = 1;
165        $line = $_;
166        next;
167    }
168
169    $cont = 0;
170
171    # collect any Kconfig sources
172    if (/^source\s*"(.*)"/) {
173        $kconfigs[$#kconfigs+1] = $1;
174    }
175
176    # configs found
177    if (/^\s*(menu)?config\s+(\S+)\s*$/) {
178        $state = "NEW";
179        $config = $2;
180
181        for (my $i = 0; $i < $iflevel; $i++) {
182        if ($i) {
183            $depends{$config} .= " " . $ifdeps[$i];
184        } else {
185            $depends{$config} = $ifdeps[$i];
186        }
187        $state = "DEP";
188        }
189
190    # collect the depends for the config
191    } elsif ($state eq "NEW" && /^\s*depends\s+on\s+(.*)$/) {
192        $state = "DEP";
193        $depends{$config} = $1;
194    } elsif ($state eq "DEP" && /^\s*depends\s+on\s+(.*)$/) {
195        $depends{$config} .= " " . $1;
196
197    # Get the configs that select this config
198    } elsif ($state ne "NONE" && /^\s*select\s+(\S+)/) {
199        if (defined($selects{$1})) {
200        $selects{$1} .= " " . $config;
201        } else {
202        $selects{$1} = $config;
203        }
204
205    # configs without prompts must be selected
206    } elsif ($state ne "NONE" && /^\s*tristate\s\S/) {
207        # note if the config has a prompt
208        $prompts{$config} = 1;
209
210    # Check for if statements
211    } elsif (/^if\s+(.*\S)\s*$/) {
212        my $deps = $1;
213        # remove beginning and ending non text
214        $deps =~ s/^[^a-zA-Z0-9_]*//;
215        $deps =~ s/[^a-zA-Z0-9_]*$//;
216
217        my @deps = split /[^a-zA-Z0-9_]+/, $deps;
218
219        $ifdeps[$iflevel++] = join ':', @deps;
220
221    } elsif (/^endif/) {
222
223        $iflevel-- if ($iflevel);
224
225    # stop on "help"
226    } elsif (/^\s*help\s*$/) {
227        $state = "NONE";
228    }
229    }
230    close(KIN);
231
232    # read in any configs that were found.
233    foreach $kconfig (@kconfigs) {
234    if (!defined($read_kconfigs{$kconfig})) {
235        $read_kconfigs{$kconfig} = 1;
236        read_kconfig($kconfig);
237    }
238    }
239}
240
241if ($kconfig) {
242    read_kconfig($kconfig);
243}
244
245# Read all Makefiles to map the configs to the objects
246foreach my $makefile (@makefiles) {
247
248    my $cont = 0;
249
250    open(MIN,$makefile) || die "Can't open $makefile";
251    while (<MIN>) {
252    my $objs;
253
254    # is this a line after a line with a backslash?
255    if ($cont && /(\S.*)$/) {
256        $objs = $1;
257    }
258    $cont = 0;
259
260    # collect objects after obj-$(CONFIG_FOO_BAR)
261    if (/obj-\$\((CONFIG_[^\)]*)\)\s*[+:]?=\s*(.*)/) {
262        $var = $1;
263        $objs = $2;
264    }
265    if (defined($objs)) {
266        # test if the line ends with a backslash
267        if ($objs =~ m,(.*)\\$,) {
268        $objs = $1;
269        $cont = 1;
270        }
271
272        foreach my $obj (split /\s+/,$objs) {
273        $obj =~ s/-/_/g;
274        if ($obj =~ /(.*)\.o$/) {
275            # Objects may be enabled by more than one config.
276            # Store configs in an array.
277            my @arr;
278
279            if (defined($objects{$1})) {
280            @arr = @{$objects{$1}};
281            }
282
283            $arr[$#arr+1] = $var;
284
285            # The objects have a hash mapping to a reference
286            # of an array of configs.
287            $objects{$1} = \@arr;
288        }
289        }
290    }
291    }
292    close(MIN);
293}
294
295my %modules;
296
297if (defined($lsmod_file)) {
298    if ( ! -f $lsmod_file) {
299    die "$lsmod_file not found";
300    }
301    if ( -x $lsmod_file) {
302    # the file is executable, run it
303    open(LIN, "$lsmod_file|");
304    } else {
305    # Just read the contents
306    open(LIN, "$lsmod_file");
307    }
308} else {
309
310    # see what modules are loaded on this system
311    my $lsmod;
312
313    foreach my $dir ( ("/sbin", "/bin", "/usr/sbin", "/usr/bin") ) {
314    if ( -x "$dir/lsmod" ) {
315        $lsmod = "$dir/lsmod";
316        last;
317    }
318}
319    if (!defined($lsmod)) {
320    # try just the path
321    $lsmod = "lsmod";
322    }
323
324    open(LIN,"$lsmod|") || die "Can not call lsmod with $lsmod";
325}
326
327while (<LIN>) {
328    next if (/^Module/); # Skip the first line.
329    if (/^(\S+)/) {
330        $modules{$1} = 1;
331    }
332}
333close (LIN);
334
335# add to the configs hash all configs that are needed to enable
336# a loaded module.
337my %configs;
338foreach my $module (keys(%modules)) {
339    if (defined($objects{$module})) {
340    my @arr = @{$objects{$module}};
341    foreach my $conf (@arr) {
342        $configs{$conf} = $module;
343    }
344    } else {
345    # Most likely, someone has a custom (binary?) module loaded.
346    print STDERR "$module config not found!!\n";
347    }
348}
349
350my $valid = "A-Za-z_0-9";
351my $repeat = 1;
352
353#
354# Note, we do not care about operands (like: &&, ||, !) we want to add any
355# config that is in the depend list of another config. This script does
356# not enable configs that are not already enabled. If we come across a
357# config A that depends on !B, we can still add B to the list of depends
358# to keep on. If A was on in the original config, B would not have been
359# and B would not be turned on by this script.
360#
361sub parse_config_dep_select
362{
363    my ($p) = @_;
364
365    while ($p =~ /[$valid]/) {
366
367    if ($p =~ /^[^$valid]*([$valid]+)/) {
368        my $conf = "CONFIG_" . $1;
369
370        $p =~ s/^[^$valid]*[$valid]+//;
371
372        if (!defined($configs{$conf})) {
373        # We must make sure that this config has its
374        # dependencies met.
375        $repeat = 1; # do again
376        $configs{$conf} = 1;
377        }
378    } else {
379        die "this should never happen";
380    }
381    }
382}
383
384while ($repeat) {
385    $repeat = 0;
386
387    foreach my $config (keys %configs) {
388    $config =~ s/^CONFIG_//;
389
390    if (defined($depends{$config})) {
391        # This config has dependencies. Make sure they are also included
392        parse_config_dep_select $depends{$config};
393    }
394
395    if (defined($prompts{$config}) || !defined($selects{$config})) {
396        next;
397    }
398
399    # config has no prompt and must be selected.
400    parse_config_dep_select $selects{$config};
401    }
402}
403
404my %setconfigs;
405
406# Finally, read the .config file and turn off any module enabled that
407# we could not find a reason to keep enabled.
408while(<CIN>) {
409
410    if (/CONFIG_IKCONFIG/) {
411    if (/# CONFIG_IKCONFIG is not set/) {
412        # enable IKCONFIG at least as a module
413        print "CONFIG_IKCONFIG=m\n";
414        # don't ask about PROC
415        print "# CONFIG_IKCONFIG_PROC is not set\n";
416    } else {
417        print;
418    }
419    next;
420    }
421
422    if (/^(CONFIG.*)=(m|y)/) {
423    if (defined($configs{$1})) {
424        $setconfigs{$1} = $2;
425    } elsif ($2 eq "m") {
426        print "# $1 is not set\n";
427        next;
428    }
429    }
430    print;
431}
432close(CIN);
433
434# Integrity check, make sure all modules that we want enabled do
435# indeed have their configs set.
436loop:
437foreach my $module (keys(%modules)) {
438    if (defined($objects{$module})) {
439    my @arr = @{$objects{$module}};
440    foreach my $conf (@arr) {
441        if (defined($setconfigs{$conf})) {
442        next loop;
443        }
444    }
445    print STDERR "module $module did not have configs";
446    foreach my $conf (@arr) {
447        print STDERR " " , $conf;
448    }
449    print STDERR "\n";
450    }
451}
452

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