#!/bin/bash

function usage()
{
    echo "Usage: $0 [option ...]"
    echo ""
    echo "Where 'option' can be one of the following:"
    echo "  -kinc <path>                 Kernel header files."
    echo "  -kpath <path>                Kernel sources."
    echo "  -kver <version>              Kernel version."
    echo "  -p <install folder>          Prefix for installing the kernel module."
}

this_dir=`pwd`

ARCH=""
TARGET="linux"
LINUX_KERNEL="/lib/modules/`uname -r`/build"
KVER=""
LIBPATH=""
INSTALL_PREFIX=""
CONFIG_FILE="Makefile.config"


while (($# > 0)) ; do
    if [ "$1" == "-help" ] || [ "$1" == "-h" ] ; then
        usage
	exit 0   
    elif [ "$1" == "-kinc" ] ; then
	if [ "$2" == "" ] ; then
	    usage
	    exit 1
	fi
        LINUX_INCLUDE="$2"
	shift 2
    elif [ "$1" == "-kpath" ] ; then
	if [ "$2" == "" ] ; then
	    usage
	    exit 1
	fi
        LINUX_KERNEL="$2"
	shift 2
    elif [ "$1" == "-kver" ] ; then
	if [ "$2" == "" ] ; then
	    usage
	    exit 1
	fi
	KVER="$2"
	shift 2
    elif [ "$1" == "-p" ] ; then
	if [ "$2" == "" ] ; then
	    usage
	    exit 1
	fi
        INSTALL_PREFIX="$2"
	shift 2
    else
        echo "ERROR: Unknown option $1"
        exit 1
    fi
done

if [ "$LINUX_INCLUDE" == "" ] ; then
    LINUX_INCLUDE="$LINUX_KERNEL/include"
fi

if [ ! -d "$LINUX_KERNEL" ] ; then
	echo "ERROR: $LINUX_KERNEL was not found."
	exit 1
fi

if [ ! -d "$LINUX_INCLUDE" ] ; then
	echo "ERROR: $LINUX_INCLUDE was not found."
	exit 1
fi

if [ "$KVER" == "" ] ; then
    if [ -f "$LINUX_INCLUDE/linux/version.h" ] ; then
	KVER=`grep UTS_RELEASE $LINUX_INCLUDE/linux/version.h | awk -- '{ if (FNR==1) { print $3 } }'`
	KVER=`echo $KVER | sed -e 's/"//g'`
    else
	echo "ERROR: $LINUX_INCLUDE/linux/version.h was not found. Configured kernel?"
	exit 1
    fi
fi

KVER1=`echo $KVER | awk -F . -- '{ print $1 }'`
KVER2=`echo $KVER | awk -F . -- '{ print $2 }'`
KVER3=`echo $KVER | sed -e "s/$KVER1\\.$KVER2\\.//g"`

case $KVER2 in
    4)
	makefile="Makefile24"
	EXT=".o"
	;;
    6)
	makefile="Makefile26"
	EXT=".ko"
	;;
esac

echo "Kernel version        : $KVER1.$KVER2.$KVER3"
echo "Module extension      : $EXT"
echo "Kernel directory      : $LINUX_KERNEL"
echo "Include directory     : $LINUX_INCLUDE"
echo "Module install prefix : $INSTALL_PREFIX"


rm -f $CONFIG_FILE
echo "# Makefile.config" >>$CONFIG_FILE
echo "# Automatically generated" >>$CONFIG_FILE
echo "KVER1=$KVER1" >>$CONFIG_FILE
echo "KVER2=$KVER2" >>$CONFIG_FILE
echo "KVER3=$KVER3" >>$CONFIG_FILE
echo "EXT=$EXT" >>$CONFIG_FILE
echo "LINUX_KERNEL=$LINUX_KERNEL" >>$CONFIG_FILE
echo "LINUX_INCLUDE=$LINUX_INCLUDE" >>$CONFIG_FILE
echo "INSTALL_PREFIX=$INSTALL_PREFIX" >>$CONFIG_FILE