/scripts/kconfig/streamline_config.pl

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