#!/bin/sh
#
# kprune: An interactive script that allows selective pruning
# of the kernel source tree, based on user input, and
# on the information contained in the ".config" file.
#
# Options:
# -a Automatic prune mode based on .config file data.
# -d Debug mode, don't delete anything. (implies "-t")
# -h Give help
# -t Keep a tally/total of kB deleted.
# -q quiet delete mode (implies "-a")
#
# The v2.0 kernel tree is now about 23MB in total and I hacked up
# this script to address that. It only targets whole directories and
# a handful of large (>50k) drivers. If that isn't good enough then
# you can do additional pruning by hand, or buy another hard disk. :)
# Use at own risk, no warranty, distributed under GPL, etc. etc.
#
# Paul Gortmaker

VERBOSE=y
AUDIT=n
AUTO=n
DEBUG=n
DISKSPACE=0
NAME=kprune

# Are we using bash (Can we *not* be ?)
if [ -z "$BASH" ];then
echo "$NAME requires bash" 1>&2
exit 1
fi

# Report some hocus-pocus usage message with optional error message to stderr
usage () {
if [ -n "$1" ];then
echo $NAME: Illegal option \"$1\" 1>&2
EXITVAL=1
else
EXITVAL=0
fi
echo "Usage: $NAME [-a] [-d] [-q] [-t]"
echo Prunes kernel of unused source based on user input and .config file.
echo -e \\t\-a\\tauto mode, delete only based on \".config\" file info.
echo -e \\t\-d\\tdebug mode, only report what would have been deleted.
echo -e \\t\-h\\tprint this help message.
echo -e \\t\-q\\tquiet mode, implies non-interactive \"-a\" mode.
echo -e \\t\-t\\ttally mode, report on total kB of files deleted.
exit $EXITVAL
}

# Delete funciton with auditing ability.
# DEBUG is for testing the script w/o untarring the kernel 50 times...
# usage: delete file1 [file2] [file3] ... [fileN]
#
function delete () {
if [ "$AUDIT" = "y" ]; then
SAVING=`du -csk $* 2> /dev/null | tail -n1 | sed 's/[ ]total//'`
DISKSPACE=$[$DISKSPACE+$SAVING]
fi
if [ "$DEBUG" = "y" ];then
echo Debug mode, would have deleted "$SAVING"kB in file\(s\):
for i in $*
do
echo -e \\t $i
done
echo Currently tagged "$DISKSPACE"kB of files.
echo
else
rm -rf $@
fi
}

# Grab some user input.
# usage: readln prompt default
#
function readln () {
if [ "$AUTO" = "y" ]; then
if [ "$VERBOSE" = "y" ]; then
echo -e "$1":\\tDefault="$2"
fi
ans=$2
else
case "$2" in
"y") defprompt="Y/n"
;;
"n") defprompt="N/y"
;;
esac

echo -n "$1" [$defprompt]
IFS='@' read ans </dev/tty || exit 1
[ -z "$ans" ] && ans=$2
fi
}

#
# Print a option group comment
# usage: comment txt_arg
#
function comment () {
if [ "$VERBOSE" = "y" ]; then
echo
echo "***" $1 "***"
echo
fi
}

# Walk a list of CONFIG_XXX;xxx;yyy;zzz args and offer to delete the file(s)
# xxx, yyy and zzz if CONFIG_XXX is not defined.
# usage: walklist "CONFIG_ABC;abc CONFIG_DEF;def1;def2 .... "
#
function walklist () {

for i in $@
do
FILES=""
OLDIFS=$IFS
IFS=\;
read OPT FILELIST <<-EOF
$i
EOF
for j in $FILELIST
do
FILES="$FILES $j"
done
IFS=$OLDIFS
OPTVAL=$(eval echo "\${$OPT}")
if [ -z "$OPTVAL" ]; then
readln "Delete $OPT files ($FILELIST)" y
if [ $ans = "y" ];then
delete $FILES
fi
fi
done

}

# Parse the user options and call them an idiot if they supply bogus opts.
for i in $*
do
case $i in
-a) AUTO="y"; continue;;
-d) DEBUG="y"; AUDIT="y"; continue;;
-h) usage;;
-t) AUDIT="y"; continue;;
-q) VERBOSE="n"; AUTO="y"; continue;;
*) usage $i;;
esac
done

# Has the user created a ".config" file yet via make {x,menu,""}config?
if [ ! -f .config ]; then
echo You must run \"make config\" before running $NAME. 1>&2
exit 1
fi

# See what the user has enabled at the moment
source .config

# The "make dep" step will barf if we prune the tree before it
# is run, so we make sure that is done before pruning as well.
if [ ! -f .depend ]; then
echo You must run \"make depend\" before using $NAME. 1>&2
exit 1
fi

# This implictly assumes that the asm dirs have the name "asm-$ARCH"
ARCHDIRS="alpha i386 m68k mips ppc sparc"

# There is no magic CONFIG_XXX that will give us the arch as easy as this.
# Using "uname -m" is ugly because it can be i[3456]86, etc.
unalias ls 2> /dev/null
ARCH=`ls -l include/asm | sed 's/^.*asm-//'`

# Lists of big architechture specific files that *aren't* tied to a
# CONFIG_XXX option. Nothing for some of these guys at the moment.
FILES_i386=""
FILES_mips=""
FILES_ppc=""
FILES_alpha="drivers/char/tga.c"
FILES_sparc="drivers/sbus"
FILES_m68k="\
drivers/block/amiflop.c \
drivers/block/ataflop.c \
drivers/scsi/atari_* "

comment "Unused Processor Architecture Specific Files"
for i in $ARCHDIRS
do
if [ $i != $ARCH ]; then
ARCH_LIST=FILES_$i
ARCH_FILES=$(eval echo "\${$ARCH_LIST}")
readln "Delete files for $i architecture" y
if [ $ans = "y" ]; then
delete arch/"$i" include/asm-"$i" $ARCH_FILES
fi
fi
done

# Various unused filesystems can be deleted as well
FSLIST="\
CONFIG_AFFS_FS;fs/affs \
CONFIG_FAT_FS;fs/msdos \
CONFIG_EXT_FS;fs/ext \
CONFIG_EXT2_FS;fs/ext2 \
CONFIG_HPFS_FS;fs/hpfs \
CONFIG_ISO9660_FS;fs/isofs \
CONFIG_MINIX_FS;fs/minix \
CONFIG_NFS_FS;fs/nfs \
CONFIG_PROC_FS;fs/proc \
CONFIG_SMB_FS;fs/smbfs \
CONFIG_UMSDOS_FS;fs/umsdos \
CONFIG_VFAT_FS;fs/vfat \
CONFIG_XIA_FS;fs/xiafs "

comment "Unused file systems"
walklist $FSLIST

# Can also nuke SCSI or at least some large drivers if not being used.
# Only the real monsters are targeted at the moment
SCSIDRVRS="\
CONFIG_BLK_DEV_SD;drivers/scsi/sd.c \
CONFIG_CHR_DEV_ST;drivers/scsi/st.c \
CONFIG_BLK_DEV_SR;drivers/scsi/sr.c \
CONFIG_CHR_DEV_SG;drivers/scsi/sg.c \
CONFIG_SCSI_ADVANSYS;drivers/scsi/advansys.* \
CONFIG_SCSI_BUSLOGIC;drivers/scsi/BusLogic.* \
CONFIG_SCSI_NCR53C7xx;drivers/scsi/53c[78]* \
CONFIG_SCSI_AIC7XXX;drivers/scsi/aic7xxx* \
CONFIG_SCSI_AM53C974;drivers/scsi/AM53C974.* \
CONFIG_SCSI_QLOGIC_ISP;drivers/scsi/qlogicisp* "

comment "Unused SCSI support/drivers"
if [ -z "$CONFIG_SCSI" ];then
walklist "CONFIG_SCSI;drivers/scsi"
else
walklist $SCSIDRVRS
fi

# drivers/char is a mess. (i.e. no subdirs). Target large files anyway.
CHARDRVRS="\
CONFIG_BAYCOM;drivers/char/baycom.c \
CONFIG_CYCLADES;drivers/char/cyclades.c \
CONFIG_DIGI;drivers/char/pcxx*;drivers/char/digi* \
CONFIG_FTAPE;drivers/char/ftape \
CONFIG_ISTALLION;drivers/char/istallion.c \
CONFIG_RISCOM8;drivers/char/riscom8* \
CONFIG_SCC;drivers/char/scc.c \
CONFIG_SERIAL;drivers/char/serial.c \
CONFIG_STALLION;drivers/char/stallion.c \
CONFIG_QIC02_TAPE;drivers/char/tpqic02.c "

comment "Unused Character Devices"
walklist $CHARDRVRS

# drivers/block is a mess. (i.e. no subdirs). Target large files anyway.
BLKDRVRS="\
CONFIG_BLK_DEV_FD;drivers/block/floppy.c \
CONFIG_BLK_DEV_IDE;drivers/block/ide.* \
CONFIG_BLK_DEV_IDECD;drivers/block/ide-cd.c \
CONFIG_BLK_DEV_IDETAPE;drivers/block/ide-tape.* "

comment "Unused Block Drivers"
walklist $BLKDRVRS

# drivers/net is a mess. (i.e. no subdirs). Target large files anyway.
# The dgrs firmware is good for 1/2 MB!!
NETDRVRS="\
CONFIG_ARCNET;drivers/net/arcnet.c \
CONFIG_DE4X5;drivers/net/de4x5.* \
CONFIG_DEPCA;drivers/net/depca.* \
CONFIG_DGRS;drivers/net/dgrs* \
CONFIG_EWRK3;drivers/net/ewrk3.* \
CONFIG_PPP;drivers/net/ppp.c \
CONFIG_PT;drivers/net/pt.* \
CONFIG_SMC9194;drivers/net/smc9194.* \
CONFIG_SK_G16;drivers/net/sk_g16.* \
CONFIG_WAVELAN;drivers/net/wavelan.* "

comment "Unused Network Device Drivers"
if [ -z "$CONFIG_NETDEVICES" ];then
walklist "CONFIG_NETDEVICES;drivers/net"
else
walklist $NETDRVRS
fi

# drivers/cdrom is a mess. (i.e. no subdirs). Target large files anyway.
CDROMDRVRS="\
CONFIG_AZTCD;drivers/cdrom/aztcd.c \
CONFIG_CDU31A;drivers/cdrom/cdu31a.c \
CONFIG_CDU535;drivers/cdrom/sonycd535.c \
CONFIG_MCDX;drivers/cdrom/mcdx.c \
CONFIG_OPTCD;drivers/cdrom/optcd.c \
CONFIG_SBPCD;drivers/cdrom/sbpcd.c "

comment "Unused CD-ROM Drivers (non IDE/SCSI)"
if [ -z "$CONFIG_CD_NO_IDESCSI" ];then
walklist "CONFIG_CD_NO_IDESCSI;drivers/cdrom"
else
walklist $CDROMDRVRS
fi

# ISDN is nice and tidy with drivers in subdirs :-)
ISDNDRVRS="\
CONFIG_ISDN_DRV_TELES;drivers/isdn/teles \
CONFIG_ISDN_DRV_ICN;drivers/isdn/icn \
CONFIG_ISDN_DRV_PCBIT;drivers/isdn/pcbit "

comment "Unused ISDN Drivers"
if [ -z "$CONFIG_ISDN" ];then
walklist "CONFIG_ISDN;drivers/isdn"
else
walklist $ISDNDRVRS
fi

# Unused net protocols, etc
NETPROTS="\
CONFIG_ATALK;net/appletalk \
CONFIG_AX25;net/ax25 \
CONFIG_BRIDGE;net/bridge \
CONFIG_INET;net/ipv4 \
CONFIG_IPX;net/ipx \
CONFIG_NET;net/802 \
CONFIG_NETROM;net/netrom "

comment "Unused Networking Protocols/Functionality"
walklist $NETPROTS

# Nuke other driver subdirs as an all or nothing approach.
comment "Misc. Other Drivers, documentation, etc."
walklist "CONFIG_SOUND;drivers/sound"
walklist "CONFIG_PCI;drivers/pci"

# Don't blast the Documentation dir unless user explicitly says "y"
# Also offer to clean up misc README files, Changelog, etc.
readln "Delete Documentation directory and all README/Changelog files" n
if [ $ans = "y" ];then
delete Documentation
READMES=`find . -name 'README*' -print`
if [ -n "$READMES" ];then
delete $READMES
fi
CHANGELOG=`find . -name 'Change*' -print`
if [ -n "$CHANGELOG" ];then
delete $CHANGELOG
fi
fi

if [ "$AUDIT" = "y" ];then
echo; echo "There was a total of "$DISKSPACE"kB of deleted files."
fi

if [ "$VERBOSE" = "y" ];then
echo
echo "After compiling and installing the kernel, you may wish to do:"
echo -e \\t"rm -f vmlinux"
echo -e \\t"rm -f arch/i386/boot/compressed/piggy.o"
echo -e \\t"rm -f arch/i386/boot/compressed/vmlinux"
echo -e \\t"rm -f arch/i386/boot/zImage"
echo -e \\t"rm -f core \`find . -name '*.a' -print\`"
echo "to recover 2 -> 3MB without sacrificing future rebuild times."
echo
fi