path: root/eclass/linux-mod.eclass

# Copyright 1999-2021 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2

# @ECLASS: linux-mod.eclass
# @MAINTAINER:
# kernel@gentoo.org
# @AUTHOR:
# John Mylchreest <johnm@gentoo.org>,
# Stefan Schweizer <genstef@gentoo.org>
# @SUPPORTED_EAPIS: 5 6 7
# @PROVIDES: linux-info
# @BLURB: It provides the functionality required to install external modules against a kernel source tree.
# @DESCRIPTION:
# This eclass is used to interface with linux-info.eclass in such a way
# to provide the functionality and initial functions
# required to install external modules against a kernel source
# tree.

# A Couple of env vars are available to effect usage of this eclass
# These are as follows:

# @ECLASS-VARIABLE: MODULES_OPTIONAL_USE
# @PRE_INHERIT
# @DEFAULT_UNSET
# @DESCRIPTION:
# A string containing the USE flag to use for making this eclass optional
# The recommended non-empty value is 'modules'

# @ECLASS-VARIABLE: MODULES_OPTIONAL_USE_IUSE_DEFAULT
# @PRE_INHERIT
# @DEFAULT_UNSET
# @DESCRIPTION:
# A boolean to control the IUSE default state for the MODULES_OPTIONAL_USE USE
# flag. Default value is unset (false). True represented by 1 or 'on', other
# values including unset treated as false.

# @ECLASS-VARIABLE: KERNEL_DIR
# @DESCRIPTION:
# A string containing the directory of the target kernel sources. The default value is
# "/usr/src/linux"
: ${KERNEL_DIR:=/usr/src/linux}

# @ECLASS-VARIABLE: ECONF_PARAMS
# @DEFAULT_UNSET
# @DESCRIPTION:
# It's a string containing the parameters to pass to econf.
# If this is not set, then econf isn't run.

# @ECLASS-VARIABLE: BUILD_PARAMS
# @DEFAULT_UNSET
# @DESCRIPTION:
# It's a string with the parameters to pass to emake.

# @ECLASS-VARIABLE: BUILD_TARGETS
# @DESCRIPTION:
# It's a string with the build targets to pass to make. The default value is "clean module"
: ${BUILD_TARGETS:=clean module}

# @ECLASS-VARIABLE: MODULE_NAMES
# @DEFAULT_UNSET
# @DESCRIPTION:
# It's a string containing the modules to be built automatically using the default
# src_compile/src_install. It will only make ${BUILD_TARGETS} once in any directory.
#
# The structure of each MODULE_NAMES entry is as follows:
#
#   modulename(libdir:srcdir:objdir)
#
# where:
#
#   modulename = name of the module file excluding the .ko
#   libdir     = place in system modules directory where module is installed (by default it's misc)
#   srcdir     = place for ebuild to cd to before running make (by default it's ${S})
#   objdir     = place the .ko and objects are located after make runs (by default it's set to srcdir)
#
# To get an idea of how these variables are used, here's a few lines
# of code from around line 540 in this eclass:
#
#	einfo "Installing ${modulename} module"
#	cd ${objdir} || die "${objdir} does not exist"
#	insinto /lib/modules/${KV_FULL}/${libdir}
#	doins ${modulename}.${KV_OBJ} || die "doins ${modulename}.${KV_OBJ} failed"
#
# For example:
#   MODULE_NAMES="module_pci(pci:${S}/pci:${S}) module_usb(usb:${S}/usb:${S})"
#
# what this would do is
#
#   cd "${S}"/pci
#   make ${BUILD_PARAMS} ${BUILD_TARGETS}
#   cd "${S}"
#   insinto /lib/modules/${KV_FULL}/pci
#   doins module_pci.${KV_OBJ}
#
#   cd "${S}"/usb
#   make ${BUILD_PARAMS} ${BUILD_TARGETS}
#   cd "${S}"
#   insinto /lib/modules/${KV_FULL}/usb
#   doins module_usb.${KV_OBJ}

# There is also support for automated modprobe.d file generation.
# This can be explicitly enabled by setting any of the following variables.

# @ECLASS-VARIABLE: MODULESD_<modulename>_ENABLED
# @DEFAULT_UNSET
# @DESCRIPTION:
# This is used to disable the modprobe.d file generation otherwise the file will be
# always generated (unless no MODULESD_<modulename>_* variable is provided). Set to "no" to disable
# the generation of the file and the installation of the documentation.

# @ECLASS-VARIABLE: MODULESD_<modulename>_EXAMPLES
# @DEFAULT_UNSET
# @DESCRIPTION:
# This is a bash array containing a list of examples which should
# be used. If you want us to try and take a guess set this to "guess".
#
# For each array_component it's added an options line in the modprobe.d file
#
#   options array_component
#
# where array_component is "<modulename> options" (see modprobe.conf(5))

# @ECLASS-VARIABLE: MODULESD_<modulename>_ALIASES
# @DEFAULT_UNSET
# @DESCRIPTION:
# This is a bash array containing a list of associated aliases.
#
# For each array_component it's added an alias line in the modprobe.d file
#
#   alias array_component
#
# where array_component is "wildcard <modulename>" (see modprobe.conf(5))

# @ECLASS-VARIABLE: MODULESD_<modulename>_ADDITIONS
# @DEFAULT_UNSET
# @DESCRIPTION:
# This is a bash array containing a list of additional things to
# add to the bottom of the file. This can be absolutely anything.
# Each entry is a new line.

# @ECLASS-VARIABLE: MODULESD_<modulename>_DOCS
# @DEFAULT_UNSET
# @DESCRIPTION:
# This is a string list which contains the full path to any associated
# documents for <modulename>. These files are installed in the live tree.

# @ECLASS-VARIABLE: KV_OBJ
# @INTERNAL
# @DESCRIPTION:
# It's a read-only variable. It contains the extension of the kernel modules.

case ${EAPI:-0} in
	[567]) inherit eutils ;;
	*) die "${ECLASS}: EAPI ${EAPI:-0} not supported" ;;
esac

if [[ -z ${_LINUX_MOD_ECLASS} ]] ; then
_LINUX_MOD_ECLASS=1

# TODO: When adding support for future EAPIs, please audit this list
# for unused inherits and conditionalise them.
inherit linux-info multilib toolchain-funcs

case ${MODULES_OPTIONAL_USE_IUSE_DEFAULT:-n} in
  [nNfF]*|[oO][fF]*|0|-) _modules_optional_use_iuse_default='' ;;
  *) _modules_optional_use_iuse_default='+' ;;
esac

[[ -n "${_modules_optional_use_iuse_default}" ]] && case ${EAPI:-0} in
	0) die "EAPI=${EAPI} is not supported with MODULES_OPTIONAL_USE_IUSE_DEFAULT due to lack of IUSE defaults" ;;
esac

IUSE="kernel_linux dist-kernel
	${MODULES_OPTIONAL_USE:+${_modules_optional_use_iuse_default}}${MODULES_OPTIONAL_USE}"
SLOT="0"
RDEPEND="
	${MODULES_OPTIONAL_USE}${MODULES_OPTIONAL_USE:+? (}
		kernel_linux? (
			sys-apps/kmod[tools]
			dist-kernel? ( virtual/dist-kernel:= )
		)
	${MODULES_OPTIONAL_USE:+)}"
DEPEND="${RDEPEND}
    ${MODULES_OPTIONAL_USE}${MODULES_OPTIONAL_USE:+? (}
	sys-apps/sed
	kernel_linux? ( virtual/linux-sources virtual/libelf )
	${MODULES_OPTIONAL_USE:+)}"

# eclass utilities
# ----------------------------------

check_vermagic() {
	debug-print-function ${FUNCNAME} $*

	local curr_gcc_ver=$(gcc -dumpversion)
	local tmpfile old_chost old_gcc_ver result=0
	[ -n "${MODULES_OPTIONAL_USE}" ] && use !${MODULES_OPTIONAL_USE} && return

	tmpfile=`find "${KV_DIR}/" -iname "*.o.cmd" -exec grep usr/lib/gcc {} \; -quit`
	tmpfile=${tmpfile//*usr/lib}
	tmpfile=${tmpfile//\/include*}
	old_chost=${tmpfile//*gcc\/}
	old_chost=${old_chost//\/*}
	old_gcc_ver=${tmpfile//*\/}

	if [[ -z ${old_gcc_ver} || -z ${old_chost} ]]; then
		ewarn ""
		ewarn "Unable to detect what version of GCC was used to compile"
		ewarn "the kernel. Build will continue, but you may experience problems."
	elif [[ ${curr_gcc_ver} != ${old_gcc_ver} ]]; then
		ewarn ""
		ewarn "The version of GCC you are using (${curr_gcc_ver}) does"
		ewarn "not match the version of GCC used to compile the"
		ewarn "kernel (${old_gcc_ver})."
		result=1
	elif [[ ${CHOST} != ${old_chost} ]]; then
		ewarn ""
		ewarn "The current CHOST (${CHOST}) does not match the chost"
		ewarn "used when compiling the kernel (${old_chost})."
		result=1
	fi

	if [[ ${result} -gt 0 ]]; then
		ewarn ""
		ewarn "Build will not continue, because you will experience problems."
		ewarn "To fix this either change the version of GCC you wish to use"
		ewarn "to match the kernel, or recompile the kernel first."
		die "GCC Version Mismatch."
	fi
}

# @FUNCTION: use_m
# @RETURN: true or false
# @DESCRIPTION:
# It checks if the kernel version is greater than 2.6.5.
use_m() {
	debug-print-function ${FUNCNAME} $*

	# if we haven't determined the version yet, we need too.
	get_version;

	# if the kernel version is greater than 2.6.6 then we should use
	# M= instead of SUBDIRS=
	[ ${KV_MAJOR} -ge 3 ] && return 0
	[ ${KV_MAJOR} -eq 2 -a ${KV_MINOR} -gt 5 -a ${KV_PATCH} -gt 5 ] && \
		return 0 || return 1
}

# @FUNCTION: convert_to_m
# @USAGE: </path/to/the/file>
# @DESCRIPTION:
# It converts a file (e.g. a makefile) to use M= instead of SUBDIRS=
convert_to_m() {
	debug-print-function ${FUNCNAME} $*

	if use_m
	then
		[ ! -f "${1}" ] && \
			die "convert_to_m() requires a filename as an argument"
		ebegin "Converting ${1/${WORKDIR}\//} to use M= instead of SUBDIRS="
		sed -i 's:SUBDIRS=:M=:g' "${1}"
		eend $?
	fi
}

# internal function
#
# FUNCTION: update_depmod
# DESCRIPTION:
# It updates the modules.dep file for the current kernel.
update_depmod() {
	debug-print-function ${FUNCNAME} $*

	# if we haven't determined the version yet, we need too.
	get_version;

	ebegin "Updating module dependencies for ${KV_FULL}"
	if [ -r "${KV_OUT_DIR}"/System.map ]
	then
		depmod -ae -F "${KV_OUT_DIR}"/System.map -b "${ROOT:-/}" ${KV_FULL}
		eend $?
	else
		ewarn
		ewarn "${KV_OUT_DIR}/System.map not found."
		ewarn "You must manually update the kernel module dependencies using depmod."
		eend 1
		ewarn
	fi
}

# internal function
#
# FUNCTION: move_old_moduledb
# DESCRIPTION:
# It updates the location of the database used by the module-rebuild utility.
move_old_moduledb() {
	debug-print-function ${FUNCNAME} $*

	local OLDDIR="${ROOT%/}"/usr/share/module-rebuild
	local NEWDIR="${ROOT%/}"/var/lib/module-rebuild

	if [[ -f "${OLDDIR}"/moduledb ]]; then
		[[ ! -d "${NEWDIR}" ]] && mkdir -p "${NEWDIR}"
		[[ ! -f "${NEWDIR}"/moduledb ]] && \
			mv "${OLDDIR}"/moduledb "${NEWDIR}"/moduledb
		rm -f "${OLDDIR}"/*
		rmdir "${OLDDIR}"
	fi
}

# internal function
#
# FUNCTION: update_moduledb
# DESCRIPTION:
# It adds the package to the /var/lib/module-rebuild/moduledb database used by the module-rebuild utility.
update_moduledb() {
	debug-print-function ${FUNCNAME} $*

	local MODULEDB_DIR="${ROOT%/}"/var/lib/module-rebuild
	move_old_moduledb

	if [[ ! -f "${MODULEDB_DIR}"/moduledb ]]; then
		[[ ! -d "${MODULEDB_DIR}" ]] && mkdir -p "${MODULEDB_DIR}"
		touch "${MODULEDB_DIR}"/moduledb
	fi

	if ! grep -qs ${CATEGORY}/${PN}-${PVR} "${MODULEDB_DIR}"/moduledb ; then
		einfo "Adding module to moduledb."
		echo "a:1:${CATEGORY}/${PN}-${PVR}" >> "${MODULEDB_DIR}"/moduledb
	fi
}

# internal function
#
# FUNCTION: remove_moduledb
# DESCRIPTION:
# It removes the package from the /var/lib/module-rebuild/moduledb database used by
# the module-rebuild utility.
remove_moduledb() {
	debug-print-function ${FUNCNAME} $*

	local MODULEDB_DIR="${ROOT%/}"/var/lib/module-rebuild
	move_old_moduledb

	if grep -qs ${CATEGORY}/${PN}-${PVR} "${MODULEDB_DIR}"/moduledb ; then
		einfo "Removing ${CATEGORY}/${PN}-${PVR} from moduledb."
		sed -i -e "/.*${CATEGORY}\/${PN}-${PVR}.*/d" "${MODULEDB_DIR}"/moduledb
	fi
}

# @FUNCTION: set_kvobj
# @DESCRIPTION:
# It sets the KV_OBJ variable.
set_kvobj() {
	debug-print-function ${FUNCNAME} $*

	if kernel_is ge 2 6
	then
		KV_OBJ="ko"
	else
		KV_OBJ="o"
	fi
	# Do we really need to know this?
	# Lets silence it.
	# einfo "Using KV_OBJ=${KV_OBJ}"
}

get-KERNEL_CC() {
	debug-print-function ${FUNCNAME} $*

	if [[ -n ${KERNEL_CC} ]] ; then
		echo "${KERNEL_CC}"
		return
	fi

	local kernel_cc
	if [ -n "${KERNEL_ABI}" ]; then
		# In future, an arch might want to define CC_$ABI
		#kernel_cc="$(get_abi_CC)"
		#[ -z "${kernel_cc}" ] &&
		kernel_cc="$(tc-getCC $(ABI=${KERNEL_ABI} get_abi_CHOST))"
	else
		kernel_cc=$(tc-getCC)
	fi
	echo "${kernel_cc}"
}

# internal function
#
# FUNCTION:
# USAGE: /path/to/the/modulename_without_extension
# RETURN: A file in /etc/modprobe.d
# DESCRIPTION:
# This function will generate and install the neccessary modprobe.d file from the
# information contained in the modules exported parms.
# (see the variables MODULESD_<modulename>_ENABLED, MODULESD_<modulename>_EXAMPLES,
# MODULESD_<modulename>_ALIASES, MODULESD_<modulename>_ADDITION and MODULESD_<modulename>_DOCS).
#
# At the end the documentation specified with MODULESD_<modulename>_DOCS is installed.
generate_modulesd() {
	debug-print-function ${FUNCNAME} $*
	[ -n "${MODULES_OPTIONAL_USE}" ] && use !${MODULES_OPTIONAL_USE} && return

	local 	currm_path currm currm_t t myIFS myVAR
	local 	module_docs module_enabled module_aliases \
			module_additions module_examples module_modinfo module_opts

	for currm_path in ${@}
	do
		currm=${currm_path//*\/}
		currm=$(echo ${currm} | tr '[:lower:]' '[:upper:]')
		currm_t=${currm}
		while [[ -z ${currm_t//*-*} ]]; do
			currm_t=${currm_t/-/_}
		done

		module_docs="$(eval echo \${MODULESD_${currm_t}_DOCS})"
		module_enabled="$(eval echo \${MODULESD_${currm_t}_ENABLED})"
		module_aliases="$(eval echo \${#MODULESD_${currm_t}_ALIASES[*]})"
		module_additions="$(eval echo \${#MODULESD_${currm_t}_ADDITIONS[*]})"
		module_examples="$(eval echo \${#MODULESD_${currm_t}_EXAMPLES[*]})"

		[[ ${module_aliases} -eq 0 ]] 	&& unset module_aliases
		[[ ${module_additions} -eq 0 ]]	&& unset module_additions
		[[ ${module_examples} -eq 0 ]] 	&& unset module_examples

		# If we specify we dont want it, then lets exit, otherwise we assume
		# that if its set, we do want it.
		[[ ${module_enabled} == no ]] && return 0

		# unset any unwanted variables.
		for t in ${!module_*}
		do
			[[ -z ${!t} ]] && unset ${t}
		done

		[[ -z ${!module_*} ]] && return 0

		# OK so now if we have got this far, then we know we want to continue
		# and generate the modprobe.d file.
		module_modinfo="$(modinfo -p ${currm_path}.${KV_OBJ})"
		module_config="${T}/modulesd-${currm}"

		ebegin "Preparing file for modprobe.d"
		#-----------------------------------------------------------------------
		echo "# modprobe.d configuration file for ${currm}" >> "${module_config}"
		#-----------------------------------------------------------------------
		[[ -n ${module_docs} ]] && \
			echo "# For more information please read:" >> "${module_config}"
		for t in ${module_docs}
		do
			echo "#    ${t//*\/}" >> "${module_config}"
		done
		echo >> "${module_config}"

		#-----------------------------------------------------------------------
		if [[ ${module_aliases} -gt 0 ]]
		then
			echo  "# Internal Aliases - Do not edit" >> "${module_config}"
			echo  "# ------------------------------" >> "${module_config}"

			for((t=0; t<${module_aliases}; t++))
			do
				echo "alias $(eval echo \${MODULESD_${currm}_ALIASES[$t]})" \
					>> "${module_config}"
			done
			echo '' >> "${module_config}"
		fi

		#-----------------------------------------------------------------------
		if [[ -n ${module_modinfo} ]]
		then
			echo >> "${module_config}"
			echo  "# Configurable module parameters" >> "${module_config}"
			echo  "# ------------------------------" >> "${module_config}"
			myIFS="${IFS}"
			IFS="$(echo -en "\n\b")"

			for t in ${module_modinfo}
			do
				myVAR="$(echo ${t#*:}  | grep -o "[^ ]*[0-9][ =][^ ]*" | tail -1  | grep -o "[0-9]")"
				if [[ -n ${myVAR} ]]
				then
					module_opts="${module_opts} ${t%%:*}:${myVAR}"
				fi
				echo -e "# ${t%%:*}:\t${t#*:}" >> "${module_config}"
			done
			IFS="${myIFS}"
			echo '' >> "${module_config}"
		fi

		#-----------------------------------------------------------------------
		if [[ $(eval echo \${MODULESD_${currm}_ALIASES[0]}) == guess ]]
		then
			# So lets do some guesswork eh?
			if [[ -n ${module_opts} ]]
			then
				echo "# For Example..." >> "${module_config}"
				echo "# --------------" >> "${module_config}"
				for t in ${module_opts}
				do
					echo "# options ${currm} ${t//:*}=${t//*:}" >> "${module_config}"
				done
				echo '' >> "${module_config}"
			fi
		elif [[ ${module_examples} -gt 0 ]]
		then
			echo "# For Example..." >> "${module_config}"
			echo "# --------------" >> "${module_config}"
			for((t=0; t<${module_examples}; t++))
			do
				echo "options $(eval echo \${MODULESD_${currm}_EXAMPLES[$t]})" \
					>> "${module_config}"
			done
			echo '' >> "${module_config}"
		fi

		#-----------------------------------------------------------------------
		if [[ ${module_additions} -gt 0 ]]
		then
			for((t=0; t<${module_additions}; t++))
			do
				echo "$(eval echo \${MODULESD_${currm}_ADDITIONS[$t]})" \
					>> "${module_config}"
			done
			echo '' >> "${module_config}"
		fi

		#-----------------------------------------------------------------------

		# then we install it
		insinto /etc/modprobe.d
		newins "${module_config}" "${currm_path//*\/}.conf"

		# and install any documentation we might have.
		[[ -n ${module_docs} ]] && dodoc ${module_docs}
	done
	eend 0
	return 0
}

# internal function
#
# FUNCTION: find_module_params
# USAGE: A string "NAME(LIBDIR:SRCDIR:OBJDIR)"
# RETURN: The string "modulename:NAME libdir:LIBDIR srcdir:SRCDIR objdir:OBJDIR"
# DESCRIPTION:
# Analyze the specification NAME(LIBDIR:SRCDIR:OBJDIR) of one module as described in MODULE_NAMES.
find_module_params() {
	debug-print-function ${FUNCNAME} $*

	local matched_offset=0 matched_opts=0 test="${@}" temp_var result
	local i=0 y=0 z=0

	for((i=0; i<=${#test}; i++))
	do
		case ${test:${i}:1} in
			\()		matched_offset[0]=${i};;
			\:)		matched_opts=$((${matched_opts} + 1));
					matched_offset[${matched_opts}]="${i}";;
			\))		matched_opts=$((${matched_opts} + 1));
					matched_offset[${matched_opts}]="${i}";;
		esac
	done

	for((i=0; i<=${matched_opts}; i++))
	do
		# i			= offset were working on
		# y			= last offset
		# z			= current offset - last offset
		# temp_var	= temporary name
		case ${i} in
			0)	tempvar=${test:0:${matched_offset[0]}};;
			*)	y=$((${matched_offset[$((${i} - 1))]} + 1))
				z=$((${matched_offset[${i}]} - ${matched_offset[$((${i} - 1))]}));
				z=$((${z} - 1))
				tempvar=${test:${y}:${z}};;
		esac

		case ${i} in
			0)	result="${result} modulename:${tempvar}";;
			1)	result="${result} libdir:${tempvar}";;
			2)	result="${result} srcdir:${tempvar}";;
			3)	result="${result} objdir:${tempvar}";;
		esac
	done

	echo ${result}
}

# default ebuild functions
# --------------------------------

# @FUNCTION: linux-mod_pkg_setup
# @DESCRIPTION:
# It checks the CONFIG_CHECK options (see linux-info.eclass(5)), verifies that the kernel is
# configured, verifies that the sources are prepared, verifies that the modules support is builtin
# in the kernel and sets the object extension KV_OBJ.
linux-mod_pkg_setup() {
	debug-print-function ${FUNCNAME} $*
	[ -n "${MODULES_OPTIONAL_USE}" ] && use !${MODULES_OPTIONAL_USE} && return

	local is_bin="${MERGE_TYPE}"

	# If we are installing a binpkg, take a different path.
	# use MERGE_TYPE if available (eapi>=4); else use non-PMS EMERGE_FROM (eapi<4)
	if has ${EAPI} 0 1 2 3; then
		is_bin=${EMERGE_FROM}
	fi

	if [[ ${is_bin} == binary ]]; then
		linux-mod_pkg_setup_binary
		return
	fi

	# External modules use kernel symbols (bug #591832)
	CONFIG_CHECK+=" !TRIM_UNUSED_KSYMS"

	linux-info_pkg_setup;
	require_configured_kernel
	check_kernel_built;
	strip_modulenames;
	[[ -n ${MODULE_NAMES} ]] && check_modules_supported
	set_kvobj;
	# Commented out with permission from johnm until a fixed version for arches
	# who intentionally use different kernel and userland compilers can be
	# introduced - Jason Wever <weeve@gentoo.org>, 23 Oct 2005
	#check_vermagic;
}

# @FUNCTION: linux-mod_pkg_setup_binary
# @DESCRIPTION:
# Perform all kernel option checks non-fatally, as the .config and
# /proc/config.gz might not be present. Do not do anything that requires kernel
# sources.
linux-mod_pkg_setup_binary() {
	debug-print-function ${FUNCNAME} $*
	local new_CONFIG_CHECK
	# ~ needs always to be quoted, else bash expands it.
	for config in $CONFIG_CHECK ; do
		optional='~'
		[[ ${config:0:1} == "~" ]] && optional=''
		new_CONFIG_CHECK="${new_CONFIG_CHECK} ${optional}${config}"
	done
	CONFIG_CHECK="${new_CONFIG_CHECK}"
	linux-info_pkg_setup;
}

strip_modulenames() {
	debug-print-function ${FUNCNAME} $*

	local i
	for i in ${MODULE_IGNORE}; do
		MODULE_NAMES=${MODULE_NAMES//${i}(*}
	done
}

# @FUNCTION: linux-mod_src_compile
# @DESCRIPTION:
# It compiles all the modules specified in MODULE_NAMES. For each module the econf command is
# executed only if ECONF_PARAMS is defined, the name of the target is specified by BUILD_TARGETS
# while the options are in BUILD_PARAMS (all the modules share these variables). The compilation
# happens inside ${srcdir}.
#
# Look at the description of these variables for more details.
linux-mod_src_compile() {
	debug-print-function ${FUNCNAME} $*
	[ -n "${MODULES_OPTIONAL_USE}" ] && use !${MODULES_OPTIONAL_USE} && return

	local modulename libdir srcdir objdir i n myABI="${ABI}"
	set_arch_to_kernel
	ABI="${KERNEL_ABI}"

	[[ -n ${KERNEL_DIR} ]] && addpredict "${KERNEL_DIR}/null.dwo"

	# Set CROSS_COMPILE in the environment.
	# This allows it to be overridden in local Makefiles.
	# https://bugs.gentoo.org/550428
	local -x CROSS_COMPILE=${CROSS_COMPILE-${CHOST}-}

	BUILD_TARGETS=${BUILD_TARGETS:-clean module}
	strip_modulenames;
	cd "${S}"
	touch Module.symvers
	for i in ${MODULE_NAMES}
	do
		unset libdir srcdir objdir
		for n in $(find_module_params ${i})
		do
			eval ${n/:*}=${n/*:/}
		done
		libdir=${libdir:-misc}
		srcdir=${srcdir:-${S}}
		objdir=${objdir:-${srcdir}}

		if [ ! -f "${srcdir}/.built" ];
		then
			cd "${srcdir}"
			ln -s "${S}"/Module.symvers Module.symvers
			einfo "Preparing ${modulename} module"
			if [[ -n ${ECONF_PARAMS} ]]
			then
				econf ${ECONF_PARAMS} || \
				die "Unable to run econf ${ECONF_PARAMS}"
			fi

			# This looks messy, but it is needed to handle multiple variables
			# being passed in the BUILD_* stuff where the variables also have
			# spaces that must be preserved. If don't do this, then the stuff
			# inside the variables gets used as targets for Make, which then
			# fails.
			eval "emake HOSTCC=\"$(tc-getBUILD_CC)\" \
						LDFLAGS=\"$(get_abi_LDFLAGS)\" \
						${BUILD_FIXES} \
						${BUILD_PARAMS} \
						${BUILD_TARGETS} " \
				|| die "Unable to emake HOSTCC="$(tc-getBUILD_CC)" LDFLAGS="$(get_abi_LDFLAGS)" ${BUILD_FIXES} ${BUILD_PARAMS} ${BUILD_TARGETS}"
			cd "${OLDPWD}"
			touch "${srcdir}"/.built
		fi
	done

	set_arch_to_portage
	ABI="${myABI}"
}

# @FUNCTION: linux-mod_src_install
# @DESCRIPTION:
# It install the modules specified in MODULES_NAME. The modules should be inside the ${objdir}
# directory and they are installed inside /lib/modules/${KV_FULL}/${libdir}.
#
# The modprobe.d configuration file is automatically generated if the
# MODULESD_<modulename>_* variables are defined. The only way to stop this process is by
# setting MODULESD_<modulename>_ENABLED=no. At the end the documentation specified via
# MODULESD_<modulename>_DOCS is also installed.
#
# Look at the description of these variables for more details.
linux-mod_src_install() {
	debug-print-function ${FUNCNAME} $*
	[ -n "${MODULES_OPTIONAL_USE}" ] && use !${MODULES_OPTIONAL_USE} && return

	local modulename libdir srcdir objdir i n

	[[ -n ${KERNEL_DIR} ]] && addpredict "${KERNEL_DIR}/null.dwo"

	strip_modulenames;
	for i in ${MODULE_NAMES}
	do
		unset libdir srcdir objdir
		for n in $(find_module_params ${i})
		do
			eval ${n/:*}=${n/*:/}
		done
		libdir=${libdir:-misc}
		srcdir=${srcdir:-${S}}
		objdir=${objdir:-${srcdir}}

		einfo "Installing ${modulename} module"
		cd "${objdir}" || die "${objdir} does not exist"
		insinto "${INSTALL_MOD_PATH}"/lib/modules/${KV_FULL}/${libdir}
		doins ${modulename}.${KV_OBJ} || die "doins ${modulename}.${KV_OBJ} failed"
		cd "${OLDPWD}"

		generate_modulesd "${objdir}/${modulename}"
	done
}

# @FUNCTION: linux-mod_pkg_preinst
# @DESCRIPTION:
# It checks what to do after having merged the package.
linux-mod_pkg_preinst() {
	debug-print-function ${FUNCNAME} $*
	[ -n "${MODULES_OPTIONAL_USE}" ] && use !${MODULES_OPTIONAL_USE} && return

	[ -d "${D%/}/lib/modules" ] && UPDATE_DEPMOD=true || UPDATE_DEPMOD=false
	[ -d "${D%/}/lib/modules" ] && UPDATE_MODULEDB=true || UPDATE_MODULEDB=false
}

# @FUNCTION: linux-mod_pkg_postinst
# @DESCRIPTION:
# It executes /sbin/depmod and adds the package to the /var/lib/module-rebuild/moduledb
# database (if ${D}/lib/modules is created)"
linux-mod_pkg_postinst() {
	debug-print-function ${FUNCNAME} $*
	[ -n "${MODULES_OPTIONAL_USE}" ] && use !${MODULES_OPTIONAL_USE} && return

	${UPDATE_DEPMOD} && update_depmod;
	${UPDATE_MODULEDB} && update_moduledb;
}

# @FUNCTION: linux-mod_pkg_postrm
# @DESCRIPTION:
# It removes the package from the /var/lib/module-rebuild/moduledb database but it doens't
# call /sbin/depmod because the modules are still installed.
linux-mod_pkg_postrm() {
	debug-print-function ${FUNCNAME} $*
	[ -n "${MODULES_OPTIONAL_USE}" ] && use !${MODULES_OPTIONAL_USE} && return
	remove_moduledb;
}

fi

EXPORT_FUNCTIONS pkg_setup src_compile src_install \
	pkg_preinst pkg_postinst pkg_postrm