1 #!/bin/bash

2

3 # miniconfig.sh copyright 2005 by Rob Landley <rob@landley.net>

4 # Licensed under the GNU General Public License version 2.

5

6 # Run this in the linux kernel build directory with a starting file, and

7 # it creates a file called mini.config with all the redundant lines of that

8 # .config removed. The starting file must match what the kernel outputs.

9 # If it doesn't, then run "make oldconfig" on it to get one that does.

10

11 # A miniconfig file is essentially the list of symbols you'd have to switch

12 # on if you started from "allnoconfig" and then went through menuconfig

13 # selecting what you wanted. It's just the list of symbols you're interested

14 # in, without including the ones set automatically by dependency checking.

15

16 # To use a miniconfig: make allnoconfig KCONFIG_ALLCONFIG=/path/to/mini.conf

17

18 # Miniconfig is more easily human-readable than a full .config file, and in

19 # some ways more version-independent than full .config files. On the other

20 # hand, when you update to a new kernel it won't get default values for newly

21 # created symbols (they'll be off if they didn't exist before and thus weren't

22 # in your "I need this and this and this" checklist), which can cause problems.

23

24 # See sources/more/migrate_kernel.sh for a script that expands a miniconfig

25 # to a .config under an old kernel version, copies it to a new version,

26 # runs "make oldconfig" to update it, creates a new mini.config from the

27 # result, and then shows a diff so you can see whether you want the new symbols.

28

29 export KCONFIG_NOTIMESTAMP=1

30

31 if [ $# -ne 1 ]

32 then

33 echo "Usage: miniconfig.sh configfile"

34 exit 1

35 fi

36

37 if [ ! -f "$1" ]

38 then

39 echo "Couldn't find "'"'"$1"'"'

40 exit 1

41 fi

42

43 if [ "$1" == ".config" ]

44 then

45 echo "It overwrites .config, rename it and try again."

46 exit 1

47 fi

48

49 make allnoconfig KCONFIG_ALLCONFIG="$1" > /dev/null

50 # Shouldn't need this, but kconfig goes "boing" at times...

51 yes "" | make oldconfig > /dev/null

52 if ! cmp .config "$1"

53 then

54 echo Sanity test failed, normalizing starting configuration...

55 diff -u "$1" .config

56 fi

57 cp .config .big.config

58

59 # Speed heuristic: remove all blank/comment lines

60 grep -v '^[#$]' .config | grep -v '^$' > mini.config

61 # This should never fail, but kconfig is so broken it does sometimes.

62 make allnoconfig KCONFIG_ALLCONFIG=mini.config > /dev/null

63 if ! cmp .config "$1"

64 then

65 echo Insanity test failed: reversing blank line removal heuristic.

66 cp .big.config mini.config

67 fi

68 #cp .config mini.config

69

70 echo "Calculating mini.config..."

71

72 LENGTH=`cat mini.config | wc -l`

73 OLDLENGTH=$LENGTH

74

75 # Loop through all lines in the file

76 I=1

77 while true

78 do

79 [ $I -gt $LENGTH ] && break

80 sed -n "$I,$(($I+${STRIDE:-1}-1))!p" mini.config > .config.test

81 # Do a config with this file

82 rm .config

83 make allnoconfig KCONFIG_ALLCONFIG=.config.test 2>/dev/null | head -n 1000000 > /dev/null

84 # Compare. Because we normalized at the start, the files should be identical.

85 if cmp -s .config .big.config

86 then

87 # Found unneeded line(s)

88 mv .config.test mini.config

89 LENGTH=$(($LENGTH-${STRIDE:-1}))

90 # Cosmetic: if stride tests off the end don't show total length less

91 # than number of entries found.

92 [ $I -gt $LENGTH ] && LENGTH=$(($I-1))

93 # Special case where we know the next line _is_ needed: stride 2 failed

94 # but we discarded the first line

95 [ -z "$STRIDE" ] && [ ${OLDSTRIDE:-1} -eq 2 ] && I=$(($I+1))

96 STRIDE=$(($STRIDE+1))

97 OLDSTRIDE=$STRIDE

98 else

99 # That hunk was needed

100 if [ ${STRIDE:-1} -le 1 ]

101 then

102 I=$(($I+1))

103 OLDSTRIDE=

104 fi

105 STRIDE=

106 fi

107 echo -n -e "\r[${STRIDE:-1}] $[$I-1]/$LENGTH lines $(cat mini.config | wc -c) bytes $[100-((($LENGTH-$I)*100)/$OLDLENGTH)]% "

108 done

109 rm .big.config

110 echo