#!/bin/bash

if [ "$OMK_VERBOSE" == "1" ]; then
  CMD_ECHO=echo
else
  CMD_ECHO=true
fi

if [ $# -lt 1 ] ; then
  echo "kernelcfg2mk: requires linux kernel directory as the first argument"
  exit 2
fi

LINUX_DIR="$1"

if [ $# -gt 1 ] ; then
  KERN_MODULES_DIR="$2"
fi

if [ ! -e $LINUX_DIR/.config ] ; then
  echo "kernelcfg2mk: the provided location does not point to configured kernel sources"
  echo "        check directory $LINUX_DIR"
  exit 2
fi

if [ ! -e $LINUX_DIR/.config ] ; then
  echo "kernelcfg2mk: the provided location does not point to configured kernel sources"
  echo "        check directory $LINUX_DIR"
  exit 2
fi

if [ -z "$KERN_BUILD_DIR" ]  ; then
  KERN_BUILD_DIR=`pwd`
fi

if [ -z "$KERN_MODULES_DIR" ]  ; then
  KERN_MODULES_DIR=`pwd`
fi


if [ -z "$MAKE" ]  ; then
  MAKE="make"
fi


KERN_TEST_DIR="$KERN_BUILD_DIR/kern-test-mk"

mkdir -p $KERN_TEST_DIR

$CMD_ECHO MAKERULES_DIR='$MAKERULES_DIR'
$CMD_ECHO LINUX_DIR='$LINUX_DIR'
$CMD_ECHO KERN_BUILD_DIR='$KERN_BUILD_DIR'
$CMD_ECHO KERN_MODULES_DIR='$KERN_MODULES_DIR'
$CMD_ECHO KERN_TEST_DIR='$KERN_TEST_DIR'

RETVAL="0"

LINUX_VERSION=$(grep UTS_RELEASE ${LINUX_DIR}/include/linux/version.h | \
               sed 's/[^"]*"\(.*\)\{1\}"/\1/')
if [ -z "$LINUX_VERSION" ] ; then
  LINUX_VERSION=$(grep UTS_RELEASE ${LINUX_DIR}/include/linux/utsrelease.h | \
                 sed 's/[^"]*"\(.*\)\{1\}"/\1/')
fi

LINUX_VERSION_MAJOR=$(echo ${LINUX_VERSION} | cut -d. -f1)
LINUX_VERSION_MINOR=$(echo ${LINUX_VERSION} | cut -d. -f2)

$CMD_ECHO Detected LINUX_VERSION=$LINUX_VERSION
$CMD_ECHO Detected LINUX_VERSION_MAJOR=$LINUX_VERSION_MAJOR
$CMD_ECHO Detected LINUX_VERSION_MINOR=$LINUX_VERSION_MINOR


case $LINUX_VERSION_MAJOR.$LINUX_VERSION_MINOR in


#=====================================================================
# test for 2.4.x kernels
    2.[01234])

	rm -f ${KERN_BUILD_DIR}/kernel.mk
	rm -rf ${KERN_TEST_DIR}
	mkdir ${KERN_TEST_DIR}
	if [ $? -ne 0 ] ; then
		echo "Cannot create Linux kernel test build directory \"${KERN_TEST_DIR}\""
		exit 3
	fi
	cd ${KERN_TEST_DIR}

	$CMD_ECHO Writing `pwd`/Makefile
	cat >${KERN_TEST_DIR}/Makefile <<EOF
include $LINUX_DIR/include/config/auto.conf

MODPOST_OPTS =			                 \\
 \$(if \$(CONFIG_MODVERSIONS),-m)                  \\
 \$(if \$(CONFIG_MODULE_SRCVERSION_ALL),-a,)       \\
 \$(if \$(KBUILD_EXTMOD),-i,-o) \$(kernelsymfile)   \\
 \$(if \$(KBUILD_EXTMOD),-I \$(modulesymfile))      \\
 \$(if \$(KBUILD_EXTRA_SYMBOLS), \$(patsubst %, -e %,\$(EXTRA_SYMBOLS))) \\
 \$(if \$(KBUILD_EXTMOD),-o \$(modulesymfile))      \\
 \$(if \$(CONFIG_DEBUG_SECTION_MISMATCH),,-S)      \\
 \$(if \$(CONFIG_MARKERS),-K \$(kernelmarkersfile)) \\
 \$(if \$(CONFIG_MARKERS),-M \$(markersfile))	 \\
 \$(if \$(KBUILD_EXTMOD)\$(KBUILD_MODPOST_WARN),-w) \\
 \$(if \$(cross_build),-c)

.PHONY: modules
modules:
	if [ "$OMK_VERBOSE" = "1" ]; then env; fi
	@echo LINUX_ARCH="\$(ARCH)" >>flags
	@echo LINUX_LDFLAGS="" >>flags
	@echo LINUX_ARFLAGS="\$(ARFLAGS)" >>flags
	@echo LINUX_CROSS_COMPILE="\$(CROSS_COMPILE)" >>flags
	@echo LINUX_KERNELRELEASE="\$(KERNELRELEASE)" >>flags
	@$CMD_ECHO LINUX_AFLAGS="\$(AFLAGS)"
	@echo LINUX_AFLAGS="\$(AFLAGS)" | sed 's#Iinclude#I"\$(LINUXDIR)/include"#g'>>flags
	@$CMD_ECHO LINUX_CFLAGS="\$(CFLAGS)"
	@echo LINUX_CFLAGS="\$(CFLAGS)" | sed 's#Iinclude#I"\$(LINUXDIR)/include"#g'>>flags
	@echo LINUX_MODFLAGS="\$(MODFLAGS)"
	@echo LINUX_CC="\$(CC)" >>flags
	@echo LINUX_LD="\$(LD) \$(LDFLAGS)" >>flags
	@echo LINUX_AS="\$(AS)" >>flags
	@echo LINUX_AR="\$(AR)" >>flags
	@echo LINUX_MODULE_EXT=".o" >>flags
	@echo MODPOST_OPTS="\$(MODPOST_OPTS)" >>flags

EOF

	$CMD_ECHO ${MAKE} -C ${LINUX_DIR} SUBDIRS=${KERN_TEST_DIR} modules
	${MAKE} -C ${LINUX_DIR} SUBDIRS=${KERN_TEST_DIR} modules
	if [ $? == 0 ] ; then
		cp -v flags ${KERN_MODULES_DIR}/kernel.mk	
		if [ ! $? == 0 ] ; then
			RETVAL="2"
		fi
	else
		RETVAL="1"
	fi

	cd ${KERN_BUILD_DIR}
	if [ "$OMK_VERBOSE" != "1" ]; then rm -rf ${KERN_TEST_DIR}; fi
	;;

#=====================================================================
# test for 2.6.x kernels

    2.6)

	rm -f ${KERN_BUILD_DIR}/kernel.mk
	rm -rf ${KERN_TEST_DIR}
	mkdir ${KERN_TEST_DIR}
	if [ $? -ne 0 ] ; then
		echo "Cannot create Linux kernel test build directory \"${KERN_TEST_DIR}\""
		exit 3
	fi
	cd ${KERN_TEST_DIR}

	$CMD_ECHO Writing `pwd`/Makefile
	cat >${KERN_TEST_DIR}/Makefile <<EOF
include $LINUX_DIR/include/config/auto.conf

MODPOST_OPTS =			                 \\
 \$(if \$(CONFIG_MODVERSIONS),-m)                  \\
 \$(if \$(CONFIG_MODULE_SRCVERSION_ALL),-a,)       \\
 \$(if \$(KBUILD_EXTMOD),-i,-o) \$(kernelsymfile)   \\
 \$(if \$(KBUILD_EXTMOD),-I \$(modulesymfile))      \\
 \$(if \$(KBUILD_EXTRA_SYMBOLS), \$(patsubst %, -e %,\$(EXTRA_SYMBOLS))) \\
 \$(if \$(KBUILD_EXTMOD),-o \$(modulesymfile))      \\
 \$(if \$(CONFIG_DEBUG_SECTION_MISMATCH),,-S)      \\
 \$(if \$(CONFIG_MARKERS),-K \$(kernelmarkersfile)) \\
 \$(if \$(CONFIG_MARKERS),-M \$(markersfile))	 \\
 \$(if \$(KBUILD_EXTMOD)\$(KBUILD_MODPOST_WARN),-w) \\
 \$(if \$(cross_build),-c)

obj-m += fake.o

\$(obj)/fake.c: flags
	touch \$(obj)/fake.c

ifeq (\$(KBUILD_SRC),)
  OMK_LINUX_SRC = \$(LINUXDIR)
else
  OMK_LINUX_SRC = \$(KBUILD_SRC)
endif
#\$(warning Test \$OMK_LINUX_SRC)

.PHONY: flags
flags:
	if [ "$OMK_VERBOSE" = "1" ]; then echo "Environment:" && env; fi
	@echo LINUX_SRC="\$(OMK_LINUX_SRC)" >>\$(obj)/flags
	@echo LINUX_ARCH="\$(ARCH)" >>\$(obj)/flags
	@echo LINUX_BUILDHOST="\$(KBUILD_BUILDHOST)" >>\$(obj)/flags
	@echo LINUX_LDFLAGS="" >>\$(obj)/flags
	@echo LINUX_ARFLAGS="\$(ARFLAGS)" >>\$(obj)/flags
	@echo LINUX_CROSS_COMPILE="\$(CROSS_COMPILE)" >>\$(obj)/flags
	@echo LINUX_KERNELRELEASE="\$(KERNELRELEASE)" >>\$(obj)/flags
	@$CMD_ECHO CPPFLAGS="\$(CPPFLAGS)"
	@$CMD_ECHO KBUILD_CPPFLAGS="\$(KBUILD_CPPFLAGS)"
	@$CMD_ECHO AFLAGS="\$(AFLAGS)"
	@$CMD_ECHO CFLAGS="\$(CFLAGS)"
	@$CMD_ECHO KBUILD_CFLAGS="\$(KBUILD_CFLAGS)"
	@$CMD_ECHO LINUXINCLUDE="\$(LINUXINCLUDE)"
	@$CMD_ECHO CFLAGS_MODULE="\$(CFLAGS_MODULE)"
ifdef KBUILD_CFLAGS
	@echo LINUX_CPPFLAGS="\$(KBUILD_CPPFLAGS)" | sed 's#-\(I\|include\) \?\(include\|arch\)#-\1 "\$(OMK_LINUX_SRC)/\2"#g'>>\$(obj)/flags
	@echo LINUX_CPPFLAGS+="\$(LINUXINCLUDE)" | sed 's#-\(I\|include\) \?\(include\|arch\)#-\1 "\$(OMK_LINUX_SRC)/\2"#g'>>\$(obj)/flags
	@echo LINUX_AFLAGS="\$(KBUILD_AFLAGS)" | sed 's#-I\(include\|arch\)#-I"\$(OMK_LINUX_SRC)/\1"#g'>>\$(obj)/flags
	@echo LINUX_CFLAGS="\$(KBUILD_CFLAGS)" | sed 's#-I\(include\|arch\)#-I"\$(OMK_LINUX_SRC)/\1"#g'>>\$(obj)/flags
else
	@echo LINUX_CPPFLAGS="\$(CPPFLAGS)" | sed 's#Iinclude#I"\$(OMK_LINUX_SRC)/include"#g'>>\$(obj)/flags
	@echo LINUX_AFLAGS="\$(AFLAGS)" | sed 's#Iinclude#I"\$(OMK_LINUX_SRC)/include"#g'>>\$(obj)/flags
	@echo LINUX_CFLAGS="\$(CFLAGS)" | sed 's#Iinclude#I"\$(OMK_LINUX_SRC)/include"#g'>>\$(obj)/flags
endif
	@echo LINUX_CFLAGS_MODULE="\$(CFLAGS_MODULE)" >>\$(obj)/flags
	@echo LINUX_CC="\$(CC)" >>\$(obj)/flags
	@echo LINUX_LD="\$(LD) \$(LDFLAGS) \$(LDFLAGS_MODULE)" | sed 's#\(\<arch/[^ ]*\.o\>\)#"\$(OMK_LINUX_SRC)/\1"#g' >>\$(obj)/flags
	@echo LINUX_AS="\$(AS)" >>\$(obj)/flags
	@echo LINUX_AR="\$(AR)" >>\$(obj)/flags
	@echo LINUX_MODULE_EXT=".ko" >>\$(obj)/flags
	@echo LINUX_QUOTE_MODNAME=\$(if \$(findstring KBUILD_STR,\$(basename_flags)),y,) >>\$(obj)/flags
	@echo LINUX_CONFIG_MODVERSIONS=\$(CONFIG_MODVERSIONS) >>\$(obj)/flags
	@echo LINUX_CONFIG_MODULE_SRCVERSION_ALL=\$(CONFIG_MODULE_SRCVERSION_ALL) >>\$(obj)/flags
	@echo LINUX_CONFIG_DEBUG_SECTION_MISMATCH=\$(CONFIG_DEBUG_SECTION_MISMATCH) >>\$(obj)/flags
	@echo LINUX_CONFIG_MARKERS=\$(CONFIG_MARKERS) >>\$(obj)/flags
	@echo LINUX_KBUILD_EXTMOD=\$(KBUILD_EXTMOD) >>\$(obj)/flags
	@echo LINUX_KBUILD_EXTRA_SYMBOLS=\$(KBUILD_EXTRA_SYMBOLS) >>\$(obj)/flags
	@echo LINUX_KBUILD_MODPOST_WARN=\$(KBUILD_MODPOST_WARN) >>\$(obj)/flags
	@echo LINUX_CROSS_BUILD=\$(cross_build) >>\$(obj)/flags
	@echo MODPOST_OPTS="\$(MODPOST_OPTS)" >> \$(obj)/flags

EOF

#	${MAKE} -C ${LINUX_DIR} SUBDIRS=${KERN_TEST_DIR} LINUXDIR=${LINUX_DIR} MODVERDIR=${KERN_TEST_DIR} KBUILD_VERBOSE=1 modules
	${MAKE} -C ${LINUX_DIR} M=${KERN_TEST_DIR} LINUXDIR=${LINUX_DIR} MODVERDIR=${KERN_TEST_DIR}/modver KBUILD_VERBOSE=$OMK_VERBOSE modules
	#if [ $? == 0 ] ; then
		cp -v flags ${KERN_MODULES_DIR}/kernel.mk	
		if [ ! $? == 0 ] ; then
			RETVAL="2"
		fi
	#else
	#	RETVAL="1"
	#fi

	cd ${KERN_BUILD_DIR}
	if [ "$OMK_VERBOSE" != "1" ]; then rm -rf ${KERN_TEST_DIR}; fi
	;;

#=====================================================================

    *)
	echo "Unsupported Linux version $LINUX_VERSION_MAJOR.$LINUX_VERSION_MINOR"
    ;;
esac


exit ${RETVAL}