#!/bin/bash
# Bob Johnson, 23 March 2003 <livewire@gentoo.org>
# Daniel Robbins, ? 2003 <drobbins@gentoo.org>
# Robin Johnson, 28 September 2003 <robbat2@gentoo.org>
# Copyright 2002 Gentoo Technologies, Inc; http://www.gentoo.org
# Released under the GNU General Public License version 2

die() {
        [ -n "$1" ] && echo "$1"
        exit 1
}

GK_VERSION=1.9
GK_SHARE=/usr/share/genkernel
[ ! -e /sbin/functions.sh ] && die "Can't find /sbin/functions.sh; exiting."
source /sbin/functions.sh
TEMP=/tmp
CONFIG=/etc/kernels
[ ! -e /etc/kernels/settings ] && die "Can't find /etc/kernels/settings; exiting."
source /etc/kernels/settings
BUSYBOX_TARBALL=${GK_SHARE}/busybox-0.60.5.tar.bz2
BUSYBOX_DIR=busybox-0.60.5
CLOOP_TARBALL=cloop_0.68-2.tar.gz
CLOOP_DIR=cloop-0.68
MAKEOPTS="$(portageq envvar MAKEOPTS)"

doheader() {
cat <<EOF
Gentoo Linux genkernel, version ${GK_VERSION}
 Copyright 2003 Gentoo Technologies, Inc., Bob Johnson, Daniel Robbins, Robin Johnson
 Distributed under the GNU General Public License version 2
EOF
}

dohelp() {
doheader 1>&2
cat 1>&2 <<EOF
Syntax:
genkernel [-c|--config] [-B|--bootsplash] [-d|--kernel-directory DIRECTORY] \\
	  [-h|--help] [-k|--kernel-version VERSION] [-b|--buildpkg] [-s|--skip-mrproper] \\
	  [-l|--livecd] [--myconfig]
Parameters:
 -c|--config - Provides the ncurses configuration for the kernel.
 -B|--bootsplash - Build bootsplash support into the initrd.
 -d|--kernel-directory DIRECTORY - Specify a non-standard path to the kernel sources.
 -h|--help - This page.
 -k|--kernel-version VERSION - Run genkernel against a specific kernel version.
 -b|--buildpkg - Create a tarball of the kernel et al after building it.
 -s|--skip-mrproper - Skip the 'make mrproper' stage of the kernel build (useful for kernel tweaking).
 -l|--livecd - build a kernel and initrd for livecd usage
 --myconfig - will use a personal config file /etc/kernels/myconfig
 
EOF
}

# parameter defaults
MENUCONFIG="no"
MRPROPER="yes"
PACKAGE="no"
BOOTSPLASH="no"
NOINSTALL="no"
MYCONFIG="no"
KD=""
KV=""

# special vars
KD_GENERATED="yes"
KV_GENERATED="yes"

GETOPT_TEMP=`getopt -o cbBd:hk:ls --long config,bootsplash,help,kernel-version:,kernel-directory:,buildpkg,skip-mrproper,livecd,myconfig -- "$@"`
if [ $? != 0 ] ; then die "getopt error!" ; fi
# Note the quotes around `$GETOPT_TEMP': they are essential!
eval set -- "${GETOPT_TEMP}"
while true; do
	case "${1}" in
		-c|--config) MENUCONFIG="yes" ; shift ;;
		--myconfig) MYCONFIG="yes" ; shift ;;
		-B|--bootsplash) BOOTSPLASH="yes" ; shift 2 ;;
		-l|--livecd) LIVECD="yes" ; NOINSTALL="yes" ; shift ;;
		-d|--kernel-directory) KD="${2}" ; KD_GENERATED="no" ; shift 2 ;;
		-h|--help) dohelp ; die ;;
		-k|--kernel-version) KV="${2}" ; KV_GENERATED="no" ; shift 2 ;;
		-b|--buildpkg) PACKAGE="yes" ; NOINSTALL="yes" ; shift ;;
		-s|--skip-mrproper) MRPROPER="no" ; shift ;;
		--) shift ; break ;;
		*) die "Invalid argument!" ;;
	esac
done

# this is the usual case when no KD/KV is provided
generate_KV() {
	if [ ! -e /usr/src/linux ]
	then
		echo "/usr/src/linux doesn't seem to exist. Please emerge your favorite"
		echo "kernel source tree first."
		die
	fi
	
	if [ ! -h /usr/src/linux ]
	then
		echo "/usr/src/linux is not a symbolic link. Please make sure it is a"
		echo "symbolic link to your preferred kernel source tree."
		die
	fi
	
	KD=`readlink -f /usr/src/linux`
	KV="${KD##*/}"
	KV="${KV##linux-}"
}

# this is the special case when KV/KD were specified
check_KV() {
	# KV was specified but not KD, so we generate KD
	[ -z "${KD}" ] && KD="/usr/src/linux-${KV}"
	# KD was specified but not KV, so we generate KV
	if [ -z "${KV}" -a -n "${KD}" ]
	then
		KV="${KD##*/}"
		KV="${KV##linux-}"
	fi
	# check KD value
	if [ ! -d "${KD}" ]
	then
		echo "The specified kernel directory (${KD}) does not exist!"
		if [ "${KD_GENERATED}" == "yes" ]
		then
		echo "Use the --kernel-directory option if your source is not at ${KD}"
		else
		echo "Please correct your parameter to --kernel-directory"
		fi
		die
	fi
}

if [ "${KD_GENERATED}" = "yes" -a "${KV_GENERATED}" = "yes" ]
then
	generate_KV 
else
	check_KV
fi

check_bootsplash() {
	if [ ! -e "${BOOT_SPLASH_INITRD}" ]; then
		eerror "BOOT_SPLASH_INITRD must be the path to the bootsplash initrd commands"
		die
	fi
}
[ "${BOOTSPLASH}" = "yes" ] && check_bootsplash 

root_device() {
	local myroot
	local mylink
	myroot=`awk '/^[ \t]*[^#]/ { if ($2 == "/") { print $1; }}' /etc/fstab`
	if [ ! -e "$myroot" ]
	then
		echo "I can't find the root device specified in /etc/fstab: ${myroot}."
		echo "Please configure your /etc/fstab file correctly, and then try again. "
		die
	fi
	mylink="`readlink $myroot`"
	if [ $? -eq 0 ]
	then
		#expanded a symlink....
		myroot="$mylink"
	fi
	ROOT_DEVICE=$myroot
}

configuration() {
	doheader
	echo
	echo "Settings:"
#	echo " root device: ${ROOT_DEVICE}"
	if [ "$MAKEOPTS" = "" ]
	then
		echo " make options: (none) (set in make.conf)"
	else
		echo " make options: ${MAKEOPTS} (from Portage/make.conf)"
	fi
	echo " source tree: ${KD}"
	echo -n " config type: "

	if [ "$MYCONFIG" = "yes" ]
	then 
		echo -e "user supplied\n config loc: ${CONFIG}/myconfig"
	elif [ -e ${CONFIG}/config-${KV} ]
    	then
	    	echo -e "gentoo (customized)\n config loc: ${CONFIG}/config-${KV}"
    	elif [ -e ${KD}/kernel-config ]
	then
		echo -e "gentoo (default)\n config loc: ${KD}/kernel-config"
	else
		echo -e "non-gentoo (default)\n config loc: ${CONFIG}/default-config"
	fi

	echo -n " initrd config: "
	if [ -e ${KD}/settings ]
    	then
		echo "(kernel) ${KD}/settings"
    		source ${KD}/settings || die "Error sourcing ${KD}/settings; exiting."
	else
		echo "(default) ${CONFIG}/settings"
		source ${CONFIG}/settings || die "Error sourcing ${CONFIG}/settings; exiting."
	fi
	echo
	cd ${KD}
	if [ "${MRPROPER}" = "yes" ]; then
		ebegin "Running \"make mrproper\""
		#running make mrproper fixes unresolved symbol stuff when switching CPU types with
		#the custom configure option.
		make mrproper > /dev/null
		eend
	else
		einfo "Skipping mrproper as requested"
		ewarn "If you have problems compiling or running the kernel,"
		ewarn "it is recommended that you ensure mrproper is run again"
	fi
	if [ "$MYCONFIG" = "yes" ]
	then
		cp -f ${CONFIG}/myconfig ${KD}/.config || die "couldn't copy myconfig"
	elif [ -e ${CONFIG}/config-${KV} ]
    	then
    		cp -f ${CONFIG}/config-${KV} ${KD}/.config || die "couldn't copy 1"
    	elif [ -e ${KD}/kernel-config ]
	then
		cp -f ${KD}/kernel-config ${KD}/.config || die "couldn't copy 2"
	else
		cp -f ${CONFIG}/default-config ${KD}/.config || die "couldn't copy 3"
	fi
	ebegin "Running \"make oldconfig\""
	while true;do echo -e "\n";done|make oldconfig >/dev/null
	eend
	if [ "$MENUCONFIG" = "yes" ]
     	then
        	echo
		echo "You will now be able to make customizations to your kernel configuration."
		echo "Any changes you make will be saved in ${CONFIG}/config-${KV}."
		echo "Your changes will also be used automatically the next time you use"
		echo "genkernel to build the ${KV} kernel."
		echo
		echo "Hit enter to begin."
		read
		make menuconfig
		if [ $? -eq 0 ]
		then
			cp ${KD}/.config ${CONFIG}/config-${KV}
		else
			echo "Error running \"make menuconfig\"; exiting."
			die
		fi
	fi
}

compile() {
	local compile
	ebegin "Logging to /var/log/genkernel.log"; eend;
	ebegin "Starting ${KV} build"; eend
	ebegin "Running \"make dep\""
	make dep  >/var/log/genkernel.log 2>&1 ||die; eend
        ebegin "Running \"make bzImage\""
	make $MAKEOPTS bzImage >/var/log/genkernel.log 2>&1 || die; eend
	ebegin "Running \"make modules\""
	make $MAKEOPTS modules >/var/log/genkernel.log 2>&1 || die; eend
        ebegin "Running \"make modules_install\""

	if [ "$PACKAGE" = "yes" ]
	then
		install -d ${TEMP}/modules
		INSTALL_MOD_PATH="${TEMP}/modules" make modules_install >/var/log/genkernel.log 2>&1 || die; eend
		mkdir ${TEMP}/genkernel
		cp -rf ${TEMP}/modules/lib/modules/${KV} ${TEMP}/genkernel
		rm -rf ${TEMP}/modules
	else
		make modules_install >/var/log/genkernel.log 2>&1 || die; eend
	fi

	local BOOT_MOUNTED="no"
	if [ "$NOINSTALL" = "no" ]
	then
		ebegin "Mounting /boot"
		[ -z "$(mount |egrep 'on /boot')" ] && BOOT_MOUNTED="yes"
		[ "${BOOT_MOUNTED}" = "no" ] && mount /boot > /dev/null 2>&1
		retval=$?
		[ $retval -eq 0 ] && BOOT_MOUNTED="yes"
		eend $retval
	fi

	local BZIMAGE_SRC=arch/i386/boot/bzImage
	local BZIMAGE_DST=/boot/kernel-${KV}
	if [ "$LIVECD" = "yes" ]
	then
		BZIMAGE_DST=/kernel-${KV}-livecd
	elif [ "$NOINSTALL" = "yes" ]
	then
		BZIMAGE_DST=${TEMP}/kernel-${KV}
	fi

	ebegin "Moving bzImage to ${BZIMAGE_DST}"
	cp ${BZIMAGE_SRC} ${BZIMAGE_DST} || die ; eend

	# now we handle System.map

	local SYSTEMMAP_SRC=System.map
	local SYSTEMMAP_DST=/boot/System.map-${KV}
	if [ "$LIVECD" = "yes" ]
	then
		SYSTEMMAP_DST=/System.map-${KV}-livecd
	elif [ "$NOINSTALL" = "yes" ]
	then
		SYSTEMMAP_DST=${TEMP}/System.map-${KV}
	fi
	
	ebegin "Copying System.map to ${SYSTEMMAP_DST}"
	cp -f System.map ${SYSTEMMAP_DST}
		
	if [ "$NOINSTALL" = "no" ]
	then
		rm -f /boot/System.map.old
		if [ -L /boot/System.map ]
		then
			rm /boot/System.map
		elif [ -e /boot/System.map ]
		then
			mv -f /boot/System.map /boot/System.map.old
		fi
		ln -s ${SYSTEMMAP_DST} /boot/System.map
	fi

	eend
}

busybox() {
	local busy
	ebegin "Building busybox"
	cd ${TEMP}
	rm -rf ${BUSYBOX_DIR}
	tar -xjf ${BUSYBOX_TARBALL}
	cd ${BUSYBOX_DIR}
	cp Config.h Config.h.orig
	sed -e "s://#define BB_INSMOD:#define BB_INSMOD:" \
	-e "s://#define BB_PIVOT_ROOT:#define BB_PIVOT_ROOT:" \
	-e "s://#define BB_LOADKMAP:#define BB_LOADKMAP:" \
	-e "s://#define BB_LOSETUP:#define BB_LOSETUP:" \
	-e "s://#define BB_RMMOD:#define BB_RMMOD:" Config.h.orig > Config.h
	make clean
	make DOSTATIC=true
        install -d ${TEMP}/kernel-initrd
        dd if=/dev/zero of=${TEMP}/initrd bs=1k count=${INITRD_SIZE}
        mke2fs -F -q -N5000 ${TEMP}/initrd
        mount -t ext2 -o loop ${TEMP}/initrd ${TEMP}/kernel-initrd
        install -d ${TEMP}/kernel-initrd/{bin,etc,usr,proc,tmp,.initrd,new_root}
        ln -s bin ${TEMP}/kernel-initrd/sbin
        ln -s ../bin ${TEMP}/kernel-initrd/usr/bin
        ln -s ../bin ${TEMP}/kernel-initrd/usr/sbin
        install -d ${TEMP}/kernel-initrd/keymaps
        cp ${GK_SHARE}/key.lst ${TEMP}/kernel-initrd/keymaps
        tar xzf ${GK_SHARE}/bin-keymaps.tar.gz -C ${TEMP}/kernel-initrd/keymaps
        (mkdir ${TEMP}/kernel-initrd/dev;cd ${TEMP}/kernel-initrd/dev;MAKEDEV generic-i386;MAKEDEV scd)
        cat >${TEMP}/kernel-initrd/etc/fstab <<EOF
/dev/ram0       /             cramfs defaults
proc            /proc         proc   defaults  0 0
EOF
        cp ${TEMP}/${BUSYBOX_DIR}/busybox ${TEMP}/kernel-initrd/bin
        for i in '[' ash basename cat chroot clear cp dirname echo env false find \
        grep gunzip gzip insmod ln ls loadkmap losetup lsmod mkdir mknod modprobe more mount mv \
        pivot_root ps awk pwd rm rmdir rmmod sh sleep tar test touch true umount uname \
        xargs yes zcat chmod chown; do
               rm -f ${TEMP}/kernel-initrd/bin/$i
               ln  ${TEMP}/kernel-initrd/bin/busybox ${TEMP}/kernel-initrd/bin/$i
        done
	eend
}

initrd() {
        ebegin "Creating initrd"
	local modc i mods mymod
	for modc in storage firewire ataraid pcmcia usb
        do
		install -d ${TEMP}/kernel-initrd/modules/${modc}
		mods=`echo $modc | tr [:lower:] [:upper:]`_MODULES
		for i in ${!mods}
		do
			mymod=`find /lib/modules/${KV} -name "${i}.o"`
			if [ -z "${mymod}" ]
			then
				echo "Warning: ${i}.o not found; skipping..."
				continue
			fi
			cp $mymod ${TEMP}/kernel-initrd/modules/${modc}
		done
	done
        #tweak our storage module settings based on our initrd
	local LINUXRC_SRC=${GK_SHARE}/linuxrc
	if [ "$LIVECD" = "yes" ]
	then
		cd ${TEMP}
		rm -rf ${CLOOP_DIR}
		tar xzf ${GK_SHARE}/${CLOOP_TARBALL} || die "unable to extract cloop"
		cd ${CLOOP_DIR}
		make KERNEL_DIR=${KD} || die "cloop failed to build"
		cd ..
		cp ${TEMP}/${CLOOP_DIR}/cloop.o ${TEMP}/kernel-initrd/modules/cloop.o
		rm -rf ${TEMP}/${CLOOP_DIR}
		LINUXRC_SRC=${GK_SHARE}/livecdrc
	fi
        cat ${LINUXRC_SRC} | sed -e "s/##STORAGE_MODULES##/${STORAGE_MODULES}/" \
				-e "s/##FIREWIRE_MODULES##/${FIREWIRE_MODULES}/" \
				-e "s/##ATARAID_MODULES##/${ATARAID_MODULES}/" \
        			-e "s/##PCMCIA_MODULES##/${PCMCIA_MODULES}/" \
				-e "s/##USB_MODULES##/${USB_MODULES}/" \
				> ${TEMP}/kernel-initrd/linuxrc

        chmod +x ${TEMP}/kernel-initrd/linuxrc
	umount ${TEMP}/kernel-initrd
	gzip -f -9 ${TEMP}/initrd
}

bootsplash() {
	local INITRD_SRC=${TEMP}/initrd.gz
	local INITRD_DST=/boot/initrd-${KV}
	if [ "${BOOTSPLASH}" = "yes" ]
	then
		ebegin "Adding Bootsplash Initrd"
        	cat ${BOOT_SPLASH_INITRD} >> ${INITRD_SRC} 
		eend 
	fi
	if [ "$LIVECD" = "yes" ]
	then
		INITRD_DST=/initrd-${KV}-livecd
	elif [ "$NOINSTALL" = "yes" ]
	then
		INITRD_DST=${TEMP}/initrd-${KV}
	fi
	ebegin "Moving initrd to ${INITRD_DST}"
	mv -f ${INITRD_SRC} ${INITRD_DST}
	eend
	
}

buildpkg() {
	if [ "${PACKAGE}" = "yes" ]
	then
		ebegin "Building Kernel Package"
		mv ${TEMP}/kernel-${KV} ${TEMP}/genkernel || die "cannot copy kernel"
		mv ${TEMP}/initrd-${KV} ${TEMP}/genkernel || die "cannot copy initrd"
		eend
		cp -f ${KD}/.config ${TEMP}/genkernel/config >/var/log/genkernel.log 2>&1
		cd ${TEMP}
		ebegin "Copying Kernel package to /kernel-${KV}.tar.bz2"
		tar -jcvf /kernel-${KV}.tar.bz2 genkernel >/var/log/genkernel.log 2>&1 || die
		eend
		rm -rf ${TEMP}/genkernel
	fi
}

finish() {
	echo
	einfo "Build completed successfully!"
	echo
	einfo "Please specify /boot/kernel-${KV} and /boot/initrd-${KV}"
	einfo "when customizing your boot loader configuration files."
	echo
	einfo "A detailed log can be found at /var/log/genkernel.log."
	umount ${TEMP}/kernel-initrd >/var/log/genkernel.log 2>&1
	rm -rf /tmp/KV
	rm -rf ${TEMP}/kernel-initrd
	rm -rf ${TEMP}/${BUSYBOX_DIR}
}

#root_device
configuration
compile
ebegin "Building busybox"
busybox >/var/log/genkernel.log 2>&1
eend
ebegin "Creating initrd"
initrd >/var/log/genkernel.log 2>&1
eend
bootsplash
buildpkg
finish
exit 0