| #!/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 $uname = `uname -r`; | 
 | chomp $uname; | 
 |  | 
 | my @searchconfigs = ( | 
 | 	{ | 
 | 	    "file" => ".config", | 
 | 	    "exec" => "cat", | 
 | 	}, | 
 | 	{ | 
 | 	    "file" => "/proc/config.gz", | 
 | 	    "exec" => "zcat", | 
 | 	}, | 
 | 	{ | 
 | 	    "file" => "/boot/config-$uname", | 
 | 	    "exec" => "cat", | 
 | 	}, | 
 | 	{ | 
 | 	    "file" => "/boot/vmlinuz-$uname", | 
 | 	    "exec" => "scripts/extract-ikconfig", | 
 | 	    "test" => "scripts/extract-ikconfig", | 
 | 	}, | 
 | 	{ | 
 | 	    "file" => "vmlinux", | 
 | 	    "exec" => "scripts/extract-ikconfig", | 
 | 	    "test" => "scripts/extract-ikconfig", | 
 | 	}, | 
 | 	{ | 
 | 	    "file" => "/lib/modules/$uname/kernel/kernel/configs.ko", | 
 | 	    "exec" => "scripts/extract-ikconfig", | 
 | 	    "test" => "scripts/extract-ikconfig", | 
 | 	}, | 
 | 	{ | 
 | 	    "file" => "kernel/configs.ko", | 
 | 	    "exec" => "scripts/extract-ikconfig", | 
 | 	    "test" => "scripts/extract-ikconfig", | 
 | 	}, | 
 | 	{ | 
 | 	    "file" => "kernel/configs.o", | 
 | 	    "exec" => "scripts/extract-ikconfig", | 
 | 	    "test" => "scripts/extract-ikconfig", | 
 | 	}, | 
 | ); | 
 |  | 
 | sub find_config { | 
 |     foreach my $conf (@searchconfigs) { | 
 | 	my $file = $conf->{"file"}; | 
 |  | 
 | 	next if ( ! -f "$file"); | 
 |  | 
 | 	if (defined($conf->{"test"})) { | 
 | 	    `$conf->{"test"} $conf->{"file"} 2>/dev/null`; | 
 | 	    next if ($?); | 
 | 	} | 
 |  | 
 | 	my $exec = $conf->{"exec"}; | 
 |  | 
 | 	print STDERR "using config: '$file'\n"; | 
 |  | 
 | 	open(CIN, "$exec $file |") || die "Failed to run $exec $file"; | 
 | 	return; | 
 |     } | 
 |     die "No config file found"; | 
 | } | 
 |  | 
 | find_config; | 
 |  | 
 | # Get the build source and top level Kconfig file (passed in) | 
 | my $ksource = $ARGV[0]; | 
 | my $kconfig = $ARGV[1]; | 
 | my $lsmod_file = $ARGV[2]; | 
 |  | 
 | my @makefiles = `find $ksource -name Makefile 2>/dev/null`; | 
 | chomp @makefiles; | 
 |  | 
 | my %depends; | 
 | my %selects; | 
 | my %prompts; | 
 | my %objects; | 
 | my $var; | 
 | my $cont = 0; | 
 | my $iflevel = 0; | 
 | my @ifdeps; | 
 |  | 
 | # prevent recursion | 
 | my %read_kconfigs; | 
 |  | 
 | sub read_kconfig { | 
 |     my ($kconfig) = @_; | 
 |  | 
 |     my $state = "NONE"; | 
 |     my $config; | 
 |     my @kconfigs; | 
 |  | 
 |     open(KIN, "$ksource/$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; | 
 |  | 
 | 	    for (my $i = 0; $i < $iflevel; $i++) { | 
 | 		if ($i) { | 
 | 		    $depends{$config} .= " " . $ifdeps[$i]; | 
 | 		} else { | 
 | 		    $depends{$config} = $ifdeps[$i]; | 
 | 		} | 
 | 		$state = "DEP"; | 
 | 	    } | 
 |  | 
 | 	# collect the depends for the config | 
 | 	} elsif ($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; | 
 |  | 
 | 	# Check for if statements | 
 | 	} elsif (/^if\s+(.*\S)\s*$/) { | 
 | 	    my $deps = $1; | 
 | 	    # remove beginning and ending non text | 
 | 	    $deps =~ s/^[^a-zA-Z0-9_]*//; | 
 | 	    $deps =~ s/[^a-zA-Z0-9_]*$//; | 
 |  | 
 | 	    my @deps = split /[^a-zA-Z0-9_]+/, $deps; | 
 |  | 
 | 	    $ifdeps[$iflevel++] = join ':', @deps; | 
 |  | 
 | 	} elsif (/^endif/) { | 
 |  | 
 | 	    $iflevel-- if ($iflevel); | 
 |  | 
 | 	# 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 $makefile (@makefiles) { | 
 |  | 
 |     open(MIN,$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$/) { | 
 | 		    # Objects may be enabled by more than one config. | 
 | 		    # Store configs in an array. | 
 | 		    my @arr; | 
 |  | 
 | 		    if (defined($objects{$1})) { | 
 | 			@arr = @{$objects{$1}}; | 
 | 		    } | 
 |  | 
 | 		    $arr[$#arr+1] = $var; | 
 |  | 
 | 		    # The objects have a hash mapping to a reference | 
 | 		    # of an array of configs. | 
 | 		    $objects{$1} = \@arr; | 
 | 		} | 
 | 	    } | 
 | 	} | 
 |     } | 
 |     close(MIN); | 
 | } | 
 |  | 
 | my %modules; | 
 |  | 
 | if (defined($lsmod_file)) { | 
 |     if ( ! -f $lsmod_file) { | 
 | 	die "$lsmod_file not found"; | 
 |     } | 
 |     if ( -x $lsmod_file) { | 
 | 	# the file is executable, run it | 
 | 	open(LIN, "$lsmod_file|"); | 
 |     } else { | 
 | 	# Just read the contents | 
 | 	open(LIN, "$lsmod_file"); | 
 |     } | 
 | } else { | 
 |  | 
 |     # see what modules are loaded on this system | 
 |     my $lsmod; | 
 |  | 
 |     foreach $dir ( ("/sbin", "/bin", "/usr/sbin", "/usr/bin") ) { | 
 | 	if ( -x "$dir/lsmod" ) { | 
 | 	    $lsmod = "$dir/lsmod"; | 
 | 	    last; | 
 | 	} | 
 | } | 
 |     if (!defined($lsmod)) { | 
 | 	# try just the path | 
 | 	$lsmod = "lsmod"; | 
 |     } | 
 |  | 
 |     open(LIN,"$lsmod|") || die "Can not call lsmod with $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{$module})) { | 
 | 	my @arr = @{$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})) { | 
 | 	    # 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_IKCONFIG/) { | 
 | 	if (/# CONFIG_IKCONFIG is not set/) { | 
 | 	    # enable IKCONFIG at least as a module | 
 | 	    print "CONFIG_IKCONFIG=m\n"; | 
 | 	    # don't ask about PROC | 
 | 	    print "# CONFIG_IKCONFIG_PROC is not set\n"; | 
 | 	} else { | 
 | 	    print; | 
 | 	} | 
 | 	next; | 
 |     } | 
 |  | 
 |     if (/^(CONFIG.*)=(m|y)/) { | 
 | 	if (defined($configs{$1})) { | 
 | 	    $setconfigs{$1} = $2; | 
 | 	} elsif ($2 eq "m") { | 
 | 	    print "# $1 is not set\n"; | 
 | 	    next; | 
 | 	} | 
 |     } | 
 |     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"; | 
 |     } | 
 | } |