#!/bin/bash
# $Header: /root/magellan-cvs/src/virtualbox/vboxguest.sh,v 1.1 2010-08-09 20:31:47 niro Exp $
# Compiles vboxguest module for given kernel

die() { echo -e "${COLRED}$@${COLDEFAULT}"; exit 1; }
mecho() { echo -e "${COLGREEN}$@${COLDEFAULT}"; }

kernel_major_version()
{
	local ksrc="$@"
	local kv

	if [[ -z ${ksrc} ]]
	then
		kv="$(uname -r|cut -d. -f1-2)"
	else
		local version
		local patchlevel

		# get version from makefile
		version=$(grep "^VERSION[[:space:]]*=[[:space:]]*[[:digit:]]" ${ksrc}/Makefile | sed "s/^.*=[[:space:]]*\([[:digit:]]\+\)/\1/g")
		# get patchlevel from makefile
		patchlevel=$(grep "^PATCHLEVEL[[:space:]]*=[[:space:]]*[[:digit:]]" ${ksrc}/Makefile | sed "s/^.*=[[:space:]]*\([[:digit:]]\+\)/\1/g")
		# kernelversion
		kv="${version}.${patchlevel}"
	fi

	echo "${kv}"
}

mod_suffix()
{
	local ksrc="$@"
	local mod_suffix

	if [[ $(kernel_major_version ${ksrc}) = 2.6 ]]
	then
		mod_suffix="ko"
	else
		mod_suffix="o"
	fi

	echo "${mod_suffix}"
}

PVER="@@PVER@@"
BUILDROOT="$(mktemp -d)"
SRCTARBALL="/usr/src/vboxguest/vboxguest-${PVER}.tar.bz2"
SRCDIR="${BUILDROOT}/vboxguest"
KERNEL_MODULE="vboxguest"

COLRED="\033[1;6m\033[31m"
COLGREEN="\033[1;6m\033[32m"
COLDEFAULT="\033[0m"

if [[ ${NOCOLORS} = true ]]
then
	COLRED=""
	COLGREEN=""
	COLDEFAULT=""
fi

# must be root
[[ $(id -u) != 0 ]] && die "You must be r00t!"

# check for given argvs
for i in $*
do
	case $1 in
		--kernel-version) shift; KERNEL_VERSION="$1" ;;
		--kernel-sources) shift; KERNEL_SOURCES="$1" ;;
	esac
	shift
done

# some sane defaults
[[ -z ${KERNEL_VERSION} ]] && KERNEL_VERSION="$(uname -r)"
[[ -z ${KERNEL_SOURCES} ]] && KERNEL_SOURCES="/lib/modules/${KERNEL_VERSION}/source"
KERNEL_MODULE_DEST="/lib/modules/${KERNEL_VERSION}/video"
KERNEL_MODULE_SUFFIX="$(mod_suffix ${KERNEL_SOURCES})"

if [[ -f ${KERNEL_MODULE_DEST}/${KERNEL_MODULE}.${KERNEL_MODULE_SUFFIX} ]]
then
	mecho "Removing old ${KERNEL_MODULE}-module ..."
	# try to unload the module
	if [[ -n $(grep "${KERNEL_MODULE} " /proc/modules 2> /dev/null) ]]
	then
		modprobe -r ${KERNEL_MODULE}
	fi
	rm -f ${KERNEL_MODULE_DEST}/${KERNEL_MODULE}.${KERNEL_MODULE_SUFFIX}
fi

# unpack src-tarball
mecho "Uncompressing src-tarball ..."
tar xjpf ${SRCTARBALL} -C ${BUILDROOT} || die
cd ${SRCDIR}

mecho "Compiling ${KERNEL_MODULE}-module for kernel ${KERNEL_VERSION} ..."
gcc_major="$(gcc --version | grep gcc | cut -d' ' -f3|cut -d. -f1)"
export _POSIX2_VERSION="199209"
[[ $(kernel_major_version ${KERNEL_SOURCES}) = 2.6 ]] && cp 2.6.x/Makefile ${SRCDIR}
make -C ${KERNEL_SOURCES} V=0 M="$(pwd)" GCC_VER_MAJ="${gcc_major}" modules || die

mecho "Installing ${KERNEL_MODULE}-module into ${KERNEL_MODULE_DEST} ..."
install -d ${KERNEL_MODULE_DEST} || die
install -m0644 ${KERNEL_MODULE}.${KERNEL_MODULE_SUFFIX} ${KERNEL_MODULE_DEST} || die

mecho "Calculating module dependencies ..."
depmod -ae ${KERNEL_VERSION}

exit 0