Commit dcc60243 authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
Browse files

kconfig: add streamline_config.pl to scripts 



streamline_config.pl is a very powerful tool. For those that install
a kernel to a new box using the config file from the distribution know that
it can take forever to compile the kernel.

Making a custom config file that will still boot your box, but bring
down the compile time of the kernel can be quit painful, and to ask
someone that reported a bug to do this can be a large burdon since that
person may not even know how to build a kernel.

This script will perform "lsmod" to find all the modules loaded on the
current running system. It will read all the Makefiles to map which
CONFIG enables a module. It will read the Kconfig files to find the
dependencies and selects that may be needed to support a CONFIG.
Finally, it reads the .config file and removes any module "=m" that is
not needed to enable the currently loaded modules. The output goes to
standard out.

Here's a way to run the script. From the Linux directory that holds
a distribution .config.

 $ scripts/kconfig/streamline_config.pl arch/x86/Kconfig > config-sl
 $ mv .config config-save
 $ mv config-sl .config
 $ make oldconfig

Now you have a .config that will still build all your modules, but also
take much less time to build the kernel.

Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent dc8ed71e

scripts/kconfig/streamline_config.pl

0 → 100644
+291 −0
Original line number Diff line number Diff line 
#!/usr/bin/perl -w

#

# Copywrite 2005-2009 - Steven Rostedt

# Licensed under the terms of the GNU GPL License version 2

#

#  It's simple enough to figure out how this works.

#  If not, then you can ask me at stripconfig@goodmis.org

#

# What it does?

#

#   If you have installed a Linux kernel from a distribution

#   that turns on way too many modules than you need, and

#   you only want the modules you use, then this program

#   is perfect for you.

#

#   It gives you the ability to turn off all the modules that are

#   not loaded on your system.

#

# Howto:

#

#  1. Boot up the kernel that you want to stream line the config on.

#  2. Change directory to the directory holding the source of the

#       kernel that you just booted.

#  3. Copy the configuraton file to this directory as .config

#  4. Have all your devices that you need modules for connected and

#      operational (make sure that their corresponding modules are loaded)

#  5. Run this script redirecting the output to some other file

#       like config_strip.

#  6. Back up your old config (if you want too).

#  7. copy the config_strip file to .config

#  8. Run "make oldconfig"

#

#  Now your kernel is ready to be built with only the modules that

#  are loaded.

#

# Here's what I did with my Debian distribution.

#

#    cd /usr/src/linux-2.6.10

#    cp /boot/config-2.6.10-1-686-smp .config

#    ~/bin/streamline_config > config_strip

#    mv .config config_sav

#    mv config_strip .config

#    make oldconfig

#

my $config = ".config";

my $linuxpath = ".";



open(CIN,$config) || die "Can't open current config file: $config";

my @makefiles = `find $linuxpath -name Makefile`;

my %depends;

my %selects;

my %prompts;

my %objects;

my $var;

my $cont = 0;



# Get the top level Kconfig file (passed in)

my $kconfig = $ARGV[0];



# prevent recursion

my %read_kconfigs;



sub read_kconfig {

    my ($kconfig) = @_;



    my $state = "NONE";

    my $config;

    my @kconfigs;



    open(KIN, $kconfig) || die "Can't open $kconfig";

    while (<KIN>) {

	chomp;



	# collect any Kconfig sources

	if (/^source\s*"(.*)"/) {

	    $kconfigs[$#kconfigs+1] = $1;

	}



	# configs found

	if (/^\s*config\s+(\S+)\s*$/) {

	    $state = "NEW";

	    $config = $1;



	# collect the depends for the config

	} elsif ($state eq "NEW" && /^\s*depends\s+on\s+(.*)$/) {

	    $state = "DEP";

	    $depends{$config} = $1;

	} elsif ($state eq "DEP" && /^\s*depends\s+on\s+(.*)$/) {

	    $depends{$config} .= " " . $1;



	# Get the configs that select this config

	} elsif ($state ne "NONE" && /^\s*select\s+(\S+)/) {

	    if (defined($selects{$1})) {

		$selects{$1} .= " " . $config;

	    } else {

		$selects{$1} = $config;

	    }



	# configs without prompts must be selected

	} elsif ($state ne "NONE" && /^\s*tristate\s\S/) {

	    # note if the config has a prompt

	    $prompt{$config} = 1;



	# stop on "help"

	} elsif (/^\s*help\s*$/) {

	    $state = "NONE";

	}

    }

    close(KIN);



    # read in any configs that were found.

    foreach $kconfig (@kconfigs) {

	if (!defined($read_kconfigs{$kconfig})) {

	    $read_kconfigs{$kconfig} = 1;

	    read_kconfig($kconfig);

	}

    }

}



if ($kconfig) {

    read_kconfig($kconfig);

}



# Read all Makefiles to map the configs to the objects

foreach my $makefile (@makefiles) {

    chomp $makefile;



    open(MIN,$makefile) || die "Can't open $makefile";

    while (<MIN>) {

	my $objs;



	# is this a line after a line with a backslash?

	if ($cont && /(\S.*)$/) {

	    $objs = $1;

	}

	$cont = 0;



	# collect objects after obj-$(CONFIG_FOO_BAR)

	if (/obj-\$\((CONFIG_[^\)]*)\)\s*[+:]?=\s*(.*)/) {

	    $var = $1;

	    $objs = $2;

	}

	if (defined($objs)) {

	    # test if the line ends with a backslash

	    if ($objs =~ m,(.*)\\$,) {

		$objs = $1;

		$cont = 1;

	    }



	    foreach my $obj (split /\s+/,$objs) {

		$obj =~ s/-/_/g;

		if ($obj =~ /(.*)\.o$/) {

		    # Objects may bes enabled by more than one config.

		    # Store configs in an array.

		    my @arr;



		    if (defined($objects{$1})) {

			@arr = @{$objects{$1}};

		    }



		    $arr[$#arr+1] = $var;



		    # The objects have a hash mapping to a reference

		    # of an array of configs.

		    $objects{$1} = \@arr;

		}

	    }

	}

    }

    close(MIN);

}



my %modules;



# see what modules are loaded on this system

open(LIN,"/sbin/lsmod|") || die "Cant lsmod";

while (<LIN>) {

	next if (/^Module/);  # Skip the first line.

	if (/^(\S+)/) {

		$modules{$1} = 1;

	}

}

close (LIN);



# add to the configs hash all configs that are needed to enable

# a loaded module.

my %configs;

foreach my $module (keys(%modules)) {

    if (defined($objects{$module})) {

	@arr = @{$objects{$module}};

	foreach my $conf (@arr) {

	    $configs{$conf} = $module;

	}

    } else {

	# Most likely, someone has a custom (binary?) module loaded.

	print STDERR "$module config not found!!\n";

    }

}



my $valid = "A-Za-z_0-9";

my $repeat = 1;



#

# Note, we do not care about operands (like: &&, ||, !) we want to add any

# config that is in the depend list of another config. This script does

# not enable configs that are not already enabled. If we come across a

# config A that depends on !B, we can still add B to the list of depends

# to keep on. If A was on in the original config, B would not have been

# and B would not be turned on by this script.

#

sub parse_config_dep_select

{

    my ($p) = @_;



    while ($p =~ /[$valid]/) {



	if ($p =~ /^[^$valid]*([$valid]+)/) {

	    my $conf = "CONFIG_" . $1;



	    $p =~ s/^[^$valid]*[$valid]+//;



	    if (!defined($configs{$conf})) {

		# We must make sure that this config has its

		# dependencies met.

		$repeat = 1; # do again

		$configs{$conf} = 1;

	    }

	} else {

	    die "this should never happen";

	}

    }

}



while ($repeat) {

    $repeat = 0;



    foreach my $config (keys %configs) {

	$config =~ s/^CONFIG_//;



	if (!defined($depends{$config})) {

	    next;

	}



	# This config has dependencies. Make sure they are also included

	parse_config_dep_select $depends{$config};



	if (defined($prompt{$config}) || !defined($selects{$config})) {

	    next;

	}



	# config has no prompt and must be selected.

	parse_config_dep_select $selects{$config};

    }

}



my %setconfigs;



# Finally, read the .config file and turn off any module enabled that

# we could not find a reason to keep enabled.

while(<CIN>) {

	if (/^(CONFIG.*)=m/) {

		if (defined($configs{$1})) {

		    $setconfigs{$1} = 1;

		    print;

		} else {

		    print "# $1 is not set\n";

		}

	} else {

		print;

	}

}

close(CIN);



# Integrity check, make sure all modules that we want enabled do

# indeed have their configs set.

loop:

foreach my $module (keys(%modules)) {

    if (defined($objects{$module})) {

	my @arr = @{$objects{$module}};

	foreach my $conf (@arr) {

	    if (defined($setconfigs{$conf})) {

		next loop;

	    }

	}

	print STDERR "module $module did not have configs";

	foreach my $conf (@arr) {

	    print STDERR " " , $conf;

	}

	print STDERR "\n";

    }

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE