root/scripts/Configure

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#! /bin/sh
#
# This script is used to configure the linux kernel.
#
# It was inspired by the challenge in the original Configure script
# to ``do something better'', combined with the actual need to ``do
# something better'' because the old configure script wasn't flexible
# enough.
#
# Please send comments / questions / bug fixes to raymondc@microsoft.com.
#
#              ***** IMPORTANT COMPATIBILITY NOTE ****
# If configuration changes are made which might adversely effect 
# Menuconfig or xconfig, please notify the respective authors so that 
# those utilities can be updated in parallel.
#
# Menuconfig:  <roadcapw@cfw.com>
# xconfig:     <apenwarr@foxnet.net>  <eric@aib.com>
#              ****************************************
#
# Each line in the config file is a command.
#
# 050793 - use IFS='@' to get around a bug in a pre-version of bash-1.13
# with an empty IFS.
#
# 030995 (storner@osiris.ping.dk) - added support for tri-state answers,
# for selecting modules to compile.
#
# 180995 Bernhard Kaindl (bkaindl@ping.at) - added dummy functions for
# use with a config.in modified for make menuconfig.
#
# 301195 (boldt@math.ucsb.edu) - added help text support
#
# 281295 Paul Gortmaker - make tri_state functions collapse to boolean
# if module support is not enabled.
#
# 010296 Aaron Ucko (ucko@vax1.rockhurst.edu) - fix int and hex to accept
# arbitrary ranges
#
# 150296 Dick Streefland (dicks@tasking.nl) - report new configuration
# items and ask for a value even when doing a "make oldconfig"
#
# 200396 Tom Dyas (tdyas@eden.rutgers.edu) - when the module option is
# chosen for an item, define the macro <option_name>_MODULE

#
# Make sure we're really running bash.
#
# I would really have preferred to write this script in a language with
# better string handling, but alas, bash is the only scripting language
# that I can be reasonable sure everybody has on their linux machine.
#
[ -z "$BASH" ] && { echo "Configure requires bash" 1>&2; exit 1; }

# Disable filename globbing once and for all.
# Enable function cacheing.
set -f -h

#
# Dummy functions for use with a config.in modified for menuconf
#
function mainmenu_option () {
        :
}
function mainmenu_name () {
        :
}
function endmenu () {
        :
}

#
# help prints the corresponding help text from Configure.help to stdout
#
#       help variable
#
function help () {
  if [ -f Documentation/Configure.help ]
  then
     #first escape regexp special characters in the argument:
     var=$(echo "$1"|sed 's/[][\/.^$*]/\\&/g')
     #now pick out the right help text:
     text=$(sed -n "/^$var[     ]*\$/,\${
                        /^$var[         ]*\$/b
                        /^#.*/b
                        /^[     ]*\$/q
                        p
                    }" Documentation/Configure.help)
     if [ -z "$text" ]
     then
          echo; echo "  Sorry, no help available for this option yet.";echo
     else
          (echo; echo "$text"; echo) | more
     fi
  else
     echo;
     echo "  Can't access the file Documentation/Configure.help which"
     echo "  should contain the help texts."
     echo
  fi
}


#
# readln reads a line into $ans.
#
#       readln prompt default oldval
#
function readln () {
        if [ "$DEFAULT" = "-d" -a -n "$3" ]; then
                echo "$1"
                ans=$2
        else
                echo -n "$1"
                [ -z "$3" ] && echo -n "(NEW) "
                IFS='@' read ans </dev/tty || exit 1
                [ -z "$ans" ] && ans=$2
        fi
}

#
# comment does some pretty-printing
#
#       comment 'xxx'
# 
function comment () {
        echo "*"; echo "* $1" ; echo "*"
        (echo "" ; echo "#"; echo "# $1" ; echo "#") >>$CONFIG
        (echo "" ; echo "/*"; echo " * $1" ; echo " */") >>$CONFIG_H
}

#
# define_bool sets the value of a boolean argument
#
#       define_bool define value
#
function define_bool () {
        case "$2" in
         "y")
                echo "$1=y" >>$CONFIG
                echo "#define $1 1" >>$CONFIG_H
                ;;

         "m")
                echo "$1=m" >>$CONFIG
                echo "#undef  $1" >>$CONFIG_H
                echo "#define $1_MODULE 1" >>$CONFIG_H
                ;;

         "n")
                echo "# $1 is not set" >>$CONFIG
                echo "#undef  $1" >>$CONFIG_H
                ;;
        esac
        eval "$1=$2"
}

#
# bool processes a boolean argument
#
#       bool question define
#
function bool () {
        old=$(eval echo "\${$2}")
        def=${old:-'n'}
        case "$def" in
         "y" | "m") defprompt="Y/n/?"
              def="y"
              ;;
         "n") defprompt="N/y/?"
              ;;
        esac
        while :; do
          readln "$1 ($2) [$defprompt] " "$def" "$old"
          case "$ans" in
            [yY] | [yY]es ) define_bool "$2" "y"
                            break;;
            [nN] | [nN]o )  define_bool "$2" "n"
                            break;;
            * )             help "$2"
                            ;;
          esac
        done
}

#
# tristate processes a tristate argument
#
#       tristate question define
#
function tristate () {
        if [ "$CONFIG_MODULES" != "y" ]; then
          bool "$1" "$2"
        else 
          old=$(eval echo "\${$2}")
          def=${old:-'n'}
          case "$def" in
           "y") defprompt="Y/m/n/?"
                ;;
           "m") defprompt="M/n/y/?"
                ;;
           "n") defprompt="N/y/m/?"
                ;;
          esac
          while :; do
            readln "$1 ($2) [$defprompt] " "$def" "$old"
            case "$ans" in
              [yY] | [yY]es ) define_bool "$2" "y"
                              break ;;
              [nN] | [nN]o )  define_bool "$2" "n"
                              break ;;
              [mM] )          define_bool "$2" "m"
                              break ;;
              * )             help "$2"
                              ;;
            esac
          done
        fi
}

#
# dep_tristate processes a tristate argument that depends upon
# another option.  If the option we depend upon is a module,
# then the only allowable options are M or N.  If Y, then
# this is a normal tristate.  This is used in cases where modules
# are nested, and one module requires the presence of something
# else in the kernel.
#
#       tristate question define default
#
function dep_tristate () {
        old=$(eval echo "\${$2}")
        def=${old:-'n'}
        if [ "$3" = "n" ]; then
                define_bool "$2" "n"
        elif [ "$3" = "y" ]; then
                tristate "$1" "$2"
        else
           if [ "$CONFIG_MODULES" = "y" ]; then
                case "$def" in
                 "y" | "m") defprompt="M/n/?"
                      def="m"
                      ;;
                 "n") defprompt="N/m/?"
                      ;;
                esac
                while :; do
                  readln "$1 ($2) [$defprompt] " "$def" "$old"
                  case "$ans" in
                      [nN] | [nN]o )  define_bool "$2" "n"
                                      break ;;
                      [mM] )          define_bool "$2" "m"
                                      break ;;
                      [yY] | [yY]es ) echo 
   echo "  This answer is not allowed, because it is not consistent with"
   echo "  your other choices."
   echo "  This driver depends on another one which you chose to compile"
   echo "  as a module. This means that you can either compile this one"
   echo "  as a module as well (with M) or leave it out altogether (N)."
                                      echo
                                      ;;
                      * )             help "$2"
                                      ;;
                  esac
                done
           fi
        fi
}

#
# define_int sets the value of a integer argument
#
#       define_int define value
#
function define_int () {
        echo "$1=$2" >>$CONFIG
        echo "#define $1 ($2)" >>$CONFIG_H
        eval "$1=$2"
}

#
# int processes an integer argument
#
#       int question define default
#
function int () {
        old=$(eval echo "\${$2}")
        def=${old:-$3}
        while :; do
          readln "$1 ($2) [$def] " "$def" "$old"
          if expr "$ans" : '0$\|-?[1-9][0-9]*$' > /dev/null; then
            define_int "$2" "$ans"
            break
          else
            help "$2"
          fi
        done
}
#
# define_hex sets the value of a hexadecimal argument
#
#       define_hex define value
#
function define_hex () {
        echo "$1=$2" >>$CONFIG
        echo "#define $1 0x${2#*[x,X]}" >>$CONFIG_H
        eval "$1=$2"
}

#
# hex processes an hexadecimal argument
#
#       hex question define default
#
function hex () {
        old=$(eval echo "\${$2}")
        def=${old:-$3}
        def=${def#*[x,X]}
        while :; do
          readln "$1 ($2) [$def] " "$def" "$old"
          ans=${ans#*[x,X]}
         if expr "$ans" : '[0-9a-fA-F]+$' > /dev/null; then
           define_hex "$2" "$ans"
           break
         else
            help "$2"
         fi
        done
}

#
# choice processes a choice list (1-out-of-n)
#
#       choice question choice-list default
#
# The choice list has a syntax of:
#       NAME WHITESPACE VALUE { WHITESPACE NAME WHITESPACE VALUE }
# The user may enter any unique prefix of one of the NAMEs and
# choice will define VALUE as if it were a boolean option.
# VALUE must be in all uppercase.  Normally, VALUE is of the
# form CONFIG_<something>.  Thus, if the user selects <something>,
# the CPP symbol CONFIG_<something> will be defined and the
# shell variable CONFIG_<something> will be set to "y".
#
function choice () {
        question="$1"
        choices="$2"
        old=
        def=$3

        # determine default answer:
        names=""
        set -- $choices
        firstvar=$2
        while [ -n "$2" ]; do
                if [ -n "$names" ]; then
                        names="$names, $1"
                else
                        names="$1"
                fi
                if [ "$(eval echo \"\${$2}\")" = "y" ]; then
                        old=$1
                        def=$1
                fi
                shift; shift
        done

        val=""
        while [ -z "$val" ]; do
                ambg=n
                readln "$question ($names) [$def] " "$def" "$old"
                ans=$(echo $ans | tr a-z A-Z)
                set -- $choices
                while [ -n "$1" ]; do
                        name=$(echo $1 | tr a-z A-Z)
                        case "$name" in
                                "$ans"* )
                                        if [ "$name" = "$ans" ]; then
                                                val="$2"
                                                break   # stop on exact match
                                        fi
                                        if [ -n "$val" ]; then
                                                echo;echo \
                "  Sorry, \"$ans\" is ambiguous; please enter a longer string."
                                                echo
                                                val=""
                                                ambg=y
                                                break
                                        else
                                                val="$2"
                                        fi;;
                        esac
                        shift; shift
                done
                if [ "$val" = "" -a "$ambg" = "n" ]; then
                        help "$firstvar"
                fi
        done
        set -- $choices
        while [ -n "$2" ]; do
                if [ "$2" = "$val" ]; then
                        echo "  defined $val"
                        define_bool "$2" "y"
                else
                        define_bool "$2" "n"
                fi
                shift; shift
        done
}

CONFIG=.tmpconfig
CONFIG_H=.tmpconfig.h
trap "rm -f $CONFIG $CONFIG_H ; exit 1" 1 2

#
# Make sure we start out with a clean slate.
#
echo "#" > $CONFIG
echo "# Automatically generated make config: don't edit" >> $CONFIG
echo "#" >> $CONFIG

echo "/*" > $CONFIG_H
echo " * Automatically generated C config: don't edit" >> $CONFIG_H
echo " */" >> $CONFIG_H

DEFAULT=""
if [ "$1" = "-d" ] ; then
        DEFAULT="-d"
        shift
fi

CONFIG_IN=./config.in
if [ "$1" != "" ] ; then
        CONFIG_IN=$1
fi

DEFAULTS=arch/$ARCH/defconfig
if [ -f .config ]; then
  DEFAULTS=.config
fi

if [ -f $DEFAULTS ]; then
  echo "#"
  echo "# Using defaults found in" $DEFAULTS
  echo "#"
  . $DEFAULTS
  sed -e 's/# \(.*\) is not.*/\1=n/' < $DEFAULTS > /tmp/conf.$$
  . /tmp/conf.$$
  rm /tmp/conf.$$
else
  echo "#"
  echo "# No defaults found"
  echo "#"
fi

. $CONFIG_IN

rm -f .config.old
if [ -f .config ]; then
        mv .config .config.old
fi
mv .tmpconfig .config
mv .tmpconfig.h include/linux/autoconf.h

echo
echo "The linux kernel is now hopefully configured for your setup."
echo "Check the top-level Makefile for additional configuration,"
echo "and do a 'make dep ; make clean' if you want to be sure all"
echo "the files are correctly re-made"
echo

exit 0

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