freebsd-dev/sys/conf/kern.pre.mk
Mike Smith 0b3178a45c Eliminate the use of commons in the kernel and modules,
simplifying the module linking process and eliminating the risks
associated with doubly-defined variables.

Cases where commons were legitimately used (detection of
compiled-in subsystems) have been converted to use sysinits, and
any new code should use this or an equivalent practice as a
matter of course.

Modules can override this behaviour by substituting -fno-common
out of ${CFLAGS} in cases where commons are necessary
(eg. third-party object modules).  Commons will be resolved and
allocated space when the kld is linked as part of the module
build process, so they will not pose a risk to the kernel or
other modules.

Provide a mechanism for controlling the export of symbols from
the module namespace.  The EXPORT_SYMS variable may be set in the
Makefile to NO (export no symbols), a list of symbols to export,
or the name of a file containing a newline-seperated list of
symbols to be exported.  Non-exported symbols are converted to
local symbols.  If EXPORT_SYMS is not set, all global symbols are
currently exported.  This behaviour is expected to change (to
exporting no symbols) once modules have been converted.

Reviewed by:	peter (in principle)
Obtained from:	green (kmod_syms.awk)
2002-01-10 03:52:01 +00:00

97 lines
2.7 KiB
Makefile

# kern.pre.mk
#
# Unified Makefile for building kenrels. This includes all the definitions
# that need to be included before %BEFORE_DEPEND
#
# $FreeBSD$
#
# Can be overridden by makeoptions or /etc/make.conf
KERNEL_KO?= kernel
KERNEL?= kernel
KODIR?= /boot/${KERNEL}
M= ${MACHINE_ARCH}
NM?= nm
OBJCOPY?= objcopy
SIZE?= size
COPTFLAGS?=-O -pipe
.if !defined(NO_CPU_COPTFLAGS)
COPTFLAGS+= ${_CPUCFLAGS}
.endif
INCLUDES= -nostdinc -I- ${INCLMAGIC} -I. -I$S -I$S/dev
# This hack lets us use the Intel ACPICA code without spamming a new
# include path into 100+ source files.
INCLUDES+= -I$S/contrib/dev/acpica
# ... and the same for ipfilter
INCLUDES+= -I$S/contrib/ipfilter
# This hack is to allow kernel compiles to succeed on machines w/out srcdist
.if exists($S/../include)
INCLUDES+= -I$S/../include
.else
INCLUDES+= -I/usr/include
.endif
COPTS= ${INCLUDES} ${IDENT} -D_KERNEL -ffreestanding -include opt_global.h
CFLAGS= ${COPTFLAGS} ${CWARNFLAGS} ${DEBUG} ${COPTS} -fno-common
# XXX LOCORE means "don't declare C stuff" not "for locore.s".
ASM_CFLAGS= -x assembler-with-cpp -DLOCORE ${CFLAGS}
# Select the correct set of tools. Can't set OBJFORMAT here because it
# doesn't get exported into the environment, and if it were exported
# then it might break building of utilities.
FMT?= -elf
CFLAGS+= ${FMT}
DEFINED_PROF= ${PROF}
.if defined(PROF)
CFLAGS+= -malign-functions=4
.if ${PROFLEVEL} >= 2
IDENT+= -DGPROF4 -DGUPROF
PROF+= -mprofiler-epilogue
.endif
.endif
# Put configuration-specific C flags last (except for ${PROF}) so that they
# can override the others.
CFLAGS+= ${CONF_CFLAGS}
NORMAL_C= ${CC} -c ${CFLAGS} ${PROF} ${.IMPSRC}
NORMAL_C_C= ${CC} -c ${CFLAGS} ${PROF} ${.IMPSRC}
NORMAL_S= ${CC} -c ${ASM_CFLAGS} ${.IMPSRC}
PROFILE_C= ${CC} -c ${CFLAGS} ${.IMPSRC}
NORMAL_M= perl5 $S/kern/makeobjops.pl -c $<; \
${CC} -c ${CFLAGS} ${PROF} ${.PREFIX}.c
GEN_CFILES= $S/$M/$M/genassym.c
SYSTEM_CFILES= vnode_if.c hints.c env.c config.c
SYSTEM_SFILES= $S/$M/$M/locore.s
SYSTEM_DEP= Makefile ${SYSTEM_OBJS}
SYSTEM_OBJS= locore.o vnode_if.o ${OBJS} hints.o env.o config.o hack.So
SYSTEM_LD= @${LD} ${FMT} -Bdynamic -T $S/conf/ldscript.$M \
-warn-common -export-dynamic -dynamic-linker /red/herring \
-o ${.TARGET} -X ${SYSTEM_OBJS} vers.o
SYSTEM_LD_TAIL= @${OBJCOPY} --strip-symbol gcc2_compiled. ${.TARGET} ; \
${SIZE} ${FMT} ${.TARGET} ; chmod 755 ${.TARGET}
SYSTEM_DEP+= $S/conf/ldscript.$M
# MKMODULESENV is set here so that port makefiles can augment
# them.
MKMODULESENV= MAKEOBJDIRPREFIX=${.OBJDIR}/modules KMODDIR=${KODIR}
.if defined(MODULES_OVERRIDE)
MKMODULESENV+= MODULES_OVERRIDE="${MODULES_OVERRIDE}"
.endif
.if defined(DEBUG)
MKMODULESENV+= DEBUG="${DEBUG}" DEBUG_FLAGS="${DEBUG}"
.endif
all: ${KERNEL_KO}