#!/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=1.8
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=${GK_SHARE}/busybox-0.60.5.tar.bz2
BUSYBOX_DIR=busybox-0.60.5
MAKEOPTS="$(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 BOOTSPLASHINITRD] [-d|--kernel-directory DIRECTORY] \\
	  [-h|--help] [-k|--kernel-version VERSION] [-p|--package] [-s|--skip-mrproper]
Parameters:
 -c|--config - Provides the ncurses configuration for the kernel.
 -b|--bootsplash BOOTSPLASHINITRD - 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.
 -p|--package - 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).
 
EOF
}

# this was in the old code, seems obsolete as it isn't used
#KERNEL=$1

# parameter defaults
MENUCONFIG="no"
SKIP_MRPROPER="no"
PACKAGE="no"
BOOTSPLASH="no"
KD=""
KV=""

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

GETOPT_TEMP=`getopt -o cb:d:hk:ps --long config,bootsplash:,help,kernel-version:,kernel-directory:,package,skip-mrproper -- "$@"`
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 ;;
		-b|--bootsplash) BOOT_SPLASH_INITRD="${2}" ; BOOTSPLASH="yes" ; shift 2 ;;
		-d|--kernel-directory) KD="${2}" ; KD_GENERATED="no" ; shift 2 ;;
		-h|--help) dohelp ; die ;;
		-k|--kernel-version) KV="${2}" ; KV_GENERATED="no" ; shift 2 ;;
		-p|--package) PACKAGE="yes" ; shift ;;
		-s|--skip-mrproper) SKIP_MRPROPER="yes" ; 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 [ ! -s "${BOOT_SPLASH_INITRD}" ]; then
		eerror "BOOT_SPLASH_INITRD must be the path to the bootsplash initrd commands"
		die
	fi
}
[ "${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 [ -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 ${KD}
	if [ "${SKIP_MRPROPER}" = "no" ]; 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 [ -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 $MAKEOPTS modules >/var/log/genkernel.log 2>&1 || die; eend
        ebegin "Running \"make modules_install\""
	make modules_install >/var/log/genkernel.log 2>&1 || die; eend
	local BOOT_MOUNTED="no"
	[ -z "$(mount |egrep 'on /boot\>')" ] && BOOT_MOUNTED="yes"
	[ "${BOOT_MOUNTED}" = "no" ] && mount /boot > /dev/null 2>&1
	ebegin "Moving bzImage to /boot/kernel-${KV}"
        cp arch/i386/boot/bzImage /boot/kernel-${KV} || die; eend
	ebegin "Copying System.map to /boot/System.map-${KV}"
	cp System.map /boot/System.map-${KV}
	rm -f /boot/System.map.old
	if [ -L /boot/System.map ]
	then
		rm /boot/System.map
	elif [ -e /boot/System.map ]
	then
		mv -f /boot/System.map /boot/System.map.old
	fi
	ln -s System.map-${KV} /boot/System.map
	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=5000
        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}/keymaps/key.lst ${TEMP}/kernel-initrd/keymaps
        tar xzf ${GK_SHARE}/keymaps/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       /             auto 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
        cat ${GK_SHARE}/linuxrc | sed -e "s/##STORAGE_MODULES##/${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 ${TEMP}/initrd
	if [ "${BOOTSPLASH}" = "yes" ]
	then
		ebegin "Adding Bootsplash Initrd"
        	cat ${BOOT_SPLASH_INITRD} >> ${TEMP}/initrd || die
        	cp -f ${TEMP}/initrd /boot/initrd-${KV}
		eend
	else
		gzip -f -9 ${TEMP}/initrd
        	mv -f ${TEMP}/initrd.gz /boot/initrd-${KV}
		eend
	fi
}
buildpkg() {
	local build
	if [ "${PACKAGE}" = "yes" ]
	then
		ebegin "Building Kernel Package"
		mkdir ${TEMP}/genkernel
		cp /boot/kernel-${KV} ${TEMP}/genkernel
		cp /boot/initrd-${KV} ${TEMP}/genkernel
		cp -rf /lib/modules/${KV} ${TEMP}/genkernel
		cp -f /usr/src/linux-${KV}/.config ${TEMP}/genkernel/config
		cd ${TEMP}
		tar -jcvf /root/kernel-${KV}.tar.bz2 genkernel 2>&1 || die
		rm -rf ${TEMP}/genkernel
		echo $WARN " *  Copied Kernel package to /root/kernel-${KV}.tar.bz2"
		eend
	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."
	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
buildpkg
finish
exit 0