#!/bin/bash

source /etc/make.conf
progname=cl-kernel
OVERLAY_DIRECTORY="/usr/local/portage/layman/calculate"
KERNEL_CONFIG_DIR="${OVERLAY_DIRECTORY}/profiles/kernel"

SHORTOPTS="k:c:t:n:v:e:rho"
LONGOPTS="help,no-install,kerneldir:,kernel-config:,make-tarball:,kernel-name:,kernel-version:,kernel-extraversion:,remove-splash,no-clean,menuconfig,use-own-config"

print_help() {
	cat <<'EOF'
Usage: cl-kernel [options] [-c FILE|-o] [destination]

Make kernel.

Options:
  -h, --help                 Print this help message
  -k, --kerneldir DIR        Location of the kernel sources
  -c, --kernel-config FILE   Kernel configuration file to use for compilation
  -t, --make-tarball FILE    Make archive containing kernel,initramfs and modules.
  -n, --kernel-name NAME     Tag the kernel and ramdisk with a name:
                             If not defined the option defaults to
                             'calculate'
  -e, --extraversion VER     Specify extraversion for kernel
  -v, --kernel-version VER   Specify version for kernel
  -r, --remove-splash        Remove splash images from initramfs.
  -o, --use-own-config       Use config from kernel directory.
  --no-clean                 Do not run make clean before compilation
  --menuconfig               Run menuconfig after oldconfig

Examples:

The most common use is to run it like this, which build and install current kernel.

  $ cl-kernel
  
  $ cl-kernel --menuconfig --kerneldir /usr/src/linux-2.6.31-gentoo-r6

EOF
}

# Using: rm_link_with_file filename
rm_link_with_file() {
	[[ -L $1 ]] && rm -f `readlink -f $1`
	rm -f $1
}

# Using: cp_link_with_file filename suffix
cp_link_with_file() {
	if [[ -L $1 ]]
	then
		rm -f `readlink -f ${1}`$2
		cp -aH ${1} `readlink -f ${1}`$2
		ln -sf `readlink ${1}`${2} ${1}${2}
	else
		rm -f ${1}${2}
		cp -aH ${1} ${1}${2}
	fi
}

# Using: make_old_file filename (result filename.old)
# Description: move filename to filename.old (support symlinking)
make_old_file() {
	if [[ -e $1 ]]
	then
		rm_link_with_file $1.old
		cp_link_with_file $1 .old
	fi
	rm_link_with_file $1
}

parse_kernel_version() {
	if [[ ${KERNEL_VERSION} =~ ^([0-9]+)\.([0-9]+)\.([0-9]+)([-.].+)?$ ]] 
	then
		# version kernel
		KV_MAJOR=${BASH_REMATCH[1]}
		KV_MINOR=${BASH_REMATCH[2]}
		KV_PATCH=${BASH_REMATCH[3]}
		[[ -z $1 ]] && KV_TYPE=${BASH_REMATCH[4]} || KV_TYPE=$1
		OKV=${KV_MAJOR}.${KV_MINOR}.${KV_PATCH}
		KERNEL_VERSION=${OKV}${KV_TYPE}
	else
		echo "Wrong kernel version: ${KERNEL_VERSION}"
		exit 0
	fi
}

warning() {
	echo "Warning: "$1 1>&2
}

die() {
	echo  1>&2
	echo "Error: "$1 1>&2
	exit 1
}

set_kernel_version() {
	sed -ri "s/^VERSION = .*$/VERSION = $KV_MAJOR/" \
		${KERNEL_DIR}/Makefile
	sed -ri "s/^PATCHLEVEL = .*$/PATCHLEVEL = $KV_MINOR/" \
		${KERNEL_DIR}/Makefile
	sed -ri "s/^SUBLEVEL = .*$/SUBLEVEL = $KV_PATCH/" \
		${KERNEL_DIR}/Makefile
	sed -ri "s/^EXTRAVERSION = .*$/EXTRAVERSION = $KV_TYPE/" \
		${KERNEL_DIR}/Makefile
}

initramfs_unpack() {
	mkdir -p tmp/initramfs || 
		die "Catn't create temporary directory for initramfs"
	pushd tmp/initramfs >/dev/null
	# unpack initramfs
	arcmd="gzip"
	# check may be initramfs packed by lzma
	lzma -dc ${BOOT_DIR}/initramfs-${KERNEL_NAME}-*-${KERNEL_VERSION} \
		&>/dev/null && arcmd="lzma"
	${arcmd} -dc ${BOOT_DIR}/initramfs-${KERNEL_NAME}-*-${KERNEL_VERSION} |
		cpio -di &>/dev/null || die "Cann't unpack initramfs" 
	# remove old initramfs
	rm ${BOOT_DIR}/initramfs-${KERNEL_NAME}-*-${KERNEL_VERSION} ||
		warning "Cann't remove old initramfs"
}

initramfs_clean() {
	# remove sound moudles
	find -name sound -exec rm -rf {} \; &>/dev/null
	# remove splash images if need
	[[ ${REMOVE_SPLASH} == 'true' ]] &&
		rm etc/splash/tty1/images/* >/dev/null
}

initramfs_pack() {
	make_old_file ${BOOT_DIR}/initrd
	# pack new initramfs
	find * | cpio -o --quiet -H newc | 
	    gzip -9 >${BOOT_DIR}/initramfs-${KERNEL_NAME}-${KERNEL_VERSION} ||
	    die "Cann't pack initramfs"
	popd &>/dev/null
	rm -rf tmp/initramfs ||
		warning "Cann't remove temporary directory contenting initramfs"
}

rename_kernel_systemmap() {
	# rename kernel (remove arch from name)
	mv ${BOOT_DIR}/kernel-${KERNEL_NAME}-*-${KERNEL_VERSION} \
		${BOOT_DIR}/linux-${KERNEL_NAME}-${KERNEL_VERSION} ||
		die "Cann't rename kernel"
	# rename systemmap (remove arch from name)
	mv ${BOOT_DIR}/System.map-${KERNEL_NAME}-*-${KERNEL_VERSION} \
		${BOOT_DIR}/System.map-${KERNEL_NAME}-${KERNEL_VERSION} ||
		die "Cann't rename System.map"
}


install_kernel() {
	make_old_file ${BOOT_DIR}/System.map
	make_old_file ${BOOT_DIR}/vmlinuz
	rename_kernel_systemmap
	# change kernel (make symlink)
	ln -sf linux-${KERNEL_NAME}-${KERNEL_VERSION} ${BOOT_DIR}/vmlinuz ||
		warning "Cann't make vmlinuz link"
	# change System.map (make symlink)
	ln -sf System.map-${KERNEL_NAME}-${KERNEL_VERSION} \
		${BOOT_DIR}/System.map || warning "Cann't make System.map link"
	# change initramfs (make symlink)
	ln -sf initramfs-${KERNEL_NAME}-${KERNEL_VERSION} ${BOOT_DIR}/initrd ||
		warning "Cann't make initrd link"
	# copy config
	make_old_file ${BOOT_DIR}/config-${KERNEL_NAME}-${KERNEL_VERSION}
	cp ${KERNEL_CONFIG} ${BOOT_DIR}/config-${KERNEL_NAME}-${KERNEL_VERSION}
	set_new_current_kernel
	calculate --initrd
}

set_new_current_kernel() {
	# set new current kernel
	if [[ ${KERNEL_DIR} != '/usr/src/linux' ]]
	then
		# if source place in /usr/src
		if [[ ${KERNEL_DIR} =~ ^/usr/src/([^/]+)$ ]]
		then 
			rm /usr/src/linux &&
				ln -sf ${BASH_REMATCH[1]} /usr/src/linux
		else
			# is specifed absolutly path
			if [[ ${KERNEL_DIR:0:1} == '/' ]]
			then
				rm /usr/src/linux &&
					ln -sf ${KERNEL_DIR} /usr/src/linux
			fi
		fi
	fi
}

make_tarball() {
	rename_kernel_systemmap
	# remove symlink for tarball
	find lib -type l -delete || 
		warning "Cann't delete symbolic links"
	# get some files from kernel sources
	ABSKERNEL_DIR="$(dirname `readlink -f $KERNEL_DIR/Makefile`)"
	mkdir -p `pwd`${ABSKERNEL_DIR}/include/linux ||
		die "Cann't create kernel sources directory"
	pushd `pwd`${ABSKERNEL_DIR} &>/dev/null
	cp ${ABSKERNEL_DIR}/.config . ||
		die "Cann't copy kernel config"
	cp ${ABSKERNEL_DIR}/System.map . ||
		die "Cann't copy System.map"
	cp ${ABSKERNEL_DIR}/Module.symvers . ||
		die "Cann't copy Module.symvers"
	cd include/linux
	cp ${ABSKERNEL_DIR}/include/linux/version.h . ||
		die "Cann't copy version header"
	popd &>/dev/null
	tar cjf ${KERNEL_TARBALL} boot lib usr ||
		die "Cann't create kernel tarbal"
}

KERNEL_DIR=/usr/src/linux
KERNEL_CONFIG=
USE_OWN_CONFIG=false
KERNEL_TARBALL=
SYSTEMNAME=$(sed -nr '/^system/ s/^[^=]+=(.*)$/\1/p' \
	/etc/calculate/calculate.ini)
KERNEL_NAME=${SYSTEMNAME}
KERNEL_VERSION=
DESTINATION=
KERNEL_EXTRAVERSION=
REMOVE_SPLASH=false
ARCH=`arch`
NO_INSTALL=false
NOCLEAN=""
MENUCONFIG=""

OPTS=$(getopt -o $SHORTOPTS --long $LONGOPTS -n "$progname" -- "$@")

if [ $? -ne 0 ]; then
	echo "'$progname --help' for more information" 1>&2
	exit 1
fi
eval set -- "$OPTS"

while [ $# -gt 0 ]; do
	case $1 in
	-h|--help)
		print_help
		exit 0
		;;
	--menuconfig)
		MENUCONFIG="--menuconfig"
		shift 
		;;
	--no-clean)
		NOCLEAN="--no-clean"
		shift 
		;;
	-o|--use-own-config)
		[[ -n $KERNEL_CONFIG ]] && 
			die "Option '$1' cannot be used in conjunction with '--kernel-config'"
		USE_OWN_CONFIG=true
		shift
		;;
	-k|--kerneldir)
		KERNEL_DIR=$2
		shift 2
		;;
	-c|--kernel-config)
		[[ $USE_OWN_CONFIG == "true" ]] && 
			die "Option '$1' cannot be used in conjunction with '--use-own-config'"
		KERNEL_CONFIG=$2
		shift 2
		;;
	-t|--make-tarball)
		KERNEL_TARBALL=$2
		shift 2
		;;
	-r|--remove-splash)
		REMOVE_SPLASH=true
		shift
		;;
	-n|--kernel-name)
		KERNEL_NAME=$2
		shift 2
		;;
	-v|--kernel-version)
		KERNEL_VERSION=$2
		shift 2
		;;
	-e|--extraversion)
		KERNEL_EXTRAVERSION=$2
		shift 2
		;;
	--no-install)
		NO_INSTALL=true
		shift
		;;
	--)
		shift
		;;
	*)
		if [[ -z ${DESTINATION} ]]
		then
			DESTINATION=$1
			shift
		else
			die "unknown second option: $1"
		fi 
		;;
	esac
done

# check kernel directory
[[ -e ${KERNEL_DIR}/Makefile ]] ||
	die "Wrong kernel sources directory: ${KERNEL_DIR}"

[[ -z ${DESTINATION} ]] && DESTINATION="/"

# if kernel_version not defined get it from Makefile of sources
[[ -z ${KERNEL_VERSION} ]] && \
	KERNEL_VERSION=`grep \
		-e ^VERSION -e ^PATCHLEVEL -e ^SUBLEVEL -e ^EXTRAVERSION \
		${KERNEL_DIR}/Makefile \
		| sed -rn "{N;N;N;s/PATCHLEVEL = |SUBLEVEL = /./g;
			    s/EXTRAVERSION = |VERSION = |\n//g;p}"`

MODULE_INS_PATH=${DESTINATION}
mkdir -p ${DESTINATION}
# tarball should be created in empty directory
if [[ -n ${KERNEL_TARBALL} ]] && [[ $(ls $DESTINATION | wc -l ) -gt 2 ]];
then
	die "tarball should be created in empty directory, need specify destination"
fi
BOOT_DIR=${DESTINATION%/}/boot

# if specify extraversion add - or . before extraversion if it is missed
if [[ -n ${KERNEL_EXTRAVERSION} ]] && [[ ${KERNEL_EXTRAVERSION:0:1} != [.-]  ]]
then
	if [[ ${KERNEL_EXTRAVERSION:0:1} == [0-9] ]]
	then
		# dot before number
		KERNEL_EXTRAVERSION=.${KERNEL_EXTRAVERSION} 
	else
		# else - minus
		KERNEL_EXTRAVERSION=-${KERNEL_EXTRAVERSION} 
	fi
fi

parse_kernel_version ${KERNEL_EXTRAVERSION}
set_kernel_version 

# select kernel config (in kernel dir, own config or overlay kernel config)
# .config.bak used instead .config, because genkernel copy specified kernel
# config to "kernel directory/.config"
if [[ ${USE_OWN_CONFIG} != "false" ]] ||
	[[ $( readlink -f "${KERNEL_CONFIG}" ) == \
	   $( readlink -f "${KERNEL_DIR}/.config" ) ]]
then
	KERNEL_CONFIG="${KERNEL_DIR}/.config.bak"
	[[ -e ${KERNEL_DIR}/.config ]] &&
		cp ${KERNEL_DIR}/.config ${KERNEL_CONFIG} ||
			die "Not found .config in ${KERNEL_DIR}"
fi
[[ -z ${KERNEL_CONFIG} ]] && 
	KERNEL_CONFIG="${KERNEL_CONFIG_DIR}/config-${SYSTEMNAME}-${ARCH}-${OKV}"

[[ -e ${KERNEL_CONFIG} ]] ||
	die "Kernel config not found in ${KERNEL_CONFIG}"

mkdir -p ${BOOT_DIR}


# run generating kernel
genkernel --splash=tty1 --unionfs --all-ramdisk-modules --disklabel \
	--slowusb --kerneldir=${KERNEL_DIR} \
	--module-prefix=${MODULE_INS_PATH} --makeopts=${MAKEOPTS} \
	${NOCLEAN} ${MENUCONFIG} --no-save-config \
	--kernel-config=${KERNEL_CONFIG} --kernname=${KERNEL_NAME} \
	--bootdir=${BOOT_DIR} all || die "kernel was not builded"

pushd ${DESTINATION} &>/dev/null
initramfs_unpack
initramfs_clean
initramfs_pack
# if specified tarball then make archive else install kernel
[[ -n ${KERNEL_TARBALL} ]] && make_tarball || install_kernel