To: torvalds@transmeta.com Subject: [Patch] module compilation infrastructure Date: Mon, 17 Apr 2000 23:46:38 +0200 From: Olaf Titz <olaf@bigred.inka.de> Hi Linus, please consider the following patch (against 2.3.99-pre3) or a similar thing for inclusion into the kernel. It fixes the long-standing problem of finding out the right compiler options to compile external modules. This patch causes "make dep" to write a makefile fragment which can be included from a module makefile. Documentation (a little) included. Olaf --- Makefile.orig Wed Mar 22 08:38:26 2000 +++ Makefile Mon Apr 17 22:14:46 2000 @@ -347,6 +347,26 @@ rm -f $$MODLIB/.misc $$MODLIB/.allmods; \ ) +include/config/module.mak: dummy + @echo VERSION = $(VERSION) > .ver + @echo PATCHLEVEL = $(PATCHLEVEL) >> .ver + @echo SUBLEVEL = $(SUBLEVEL) >> .ver + @echo EXTRAVERSION = $(EXTRAVERSION) >> .ver + @echo ARCH = $(ARCH) >> .ver + @echo CC = $(CC) >> .ver + @echo LD = $(LD) >> .ver + @echo GENKSYMS = $(GENKSYMS) >> .ver +ifdef CONFIG_SMP + @echo CONFIG_SMP = 1 >> .ver +endif +ifdef CONFIG_MODVERSIONS + @echo CONFIG_MODVERSIONS = 1 >> .ver +endif + @(echo CFLAGS = $(CFLAGS) $(MODFLAGS) | sed 's,$(TOPDIR)/include,$$(KINCDIR),g') >> .ver + @echo LINUX_COMPILER = \"`$(CC) -v 2>&1 | tail -1`\" >> .ver + @echo include '$$(KINCDIR)/linux/module.mak' >> .ver + @mv -f .ver $@ + # modules disabled.... else @@ -357,6 +377,12 @@ @echo "Then build a kernel with module support enabled." @echo @exit 1 + +include/config/module.mak: dummy + @echo modules modules_install: > .ver + @$(MAKE) -n modules | sed -n "s/^e/ @e/p" >> .ver + @mv -f .ver $@ + endif clean: archclean @@ -376,7 +402,7 @@ rm -rf modules mrproper: clean archmrproper - rm -f include/linux/autoconf.h include/linux/version.h + rm -f include/linux/autoconf.h include/linux/version.h include/config/module.mak rm -f drivers/net/hamradio/soundmodem/sm_tbl_{afsk1200,afsk2666,fsk9600}.h rm -f drivers/net/hamradio/soundmodem/sm_tbl_{hapn4800,psk4800}.h rm -f drivers/net/hamradio/soundmodem/sm_tbl_{afsk2400_7,afsk2400_8}.h @@ -427,7 +453,7 @@ endif export MODVERFILE -depend dep: dep-files $(MODVERFILE) +depend dep: dep-files $(MODVERFILE) include/config/module.mak # make checkconfig: Prune 'scripts' directory to avoid "false positives". checkconfig: --- /dev/null Mon Jan 10 00:08:22 2000 +++ Documentation/compiling-modules.txt Mon Apr 17 23:20:18 2000 @@ -0,0 +1,33 @@ +To compile external modules, you need the include tree of a configured +kernel (after doing at least "make dep"). + +Set up a Makefile in the module's directory which contains at least +these lines: + + # Object files which make up the module: without exported symbols + M_OBJS=foo.o bar.o + # ...and with exported symbols + MX_OBJS=fred.o + # Target into which the .o files are linked + M_TARGET=squish.o + + # set this to your kernel include directory + KINCDIR=/var/export/src/linux-2.3.99-pre3/include + include $(KINCDIR)/config/module.mak + + +Then you can do... to do... + +make dep update the ksym tables if needed, + generate a dependencies file +make modules compile the objects and link them into a module +make modules_install install the module into its final location +make clean to clean up everything + +The module Makefile can define other variables, such as: + +EXTRA_CFLAGS additional CFLAGS for all objects +CFLAGS_foo.o additional CFLAGS for foo.o +PRE_CFLAGS additional CFLAGS for all objects, set first on + CC command line +INSTALL_MOD_PATH module installation root (default /) --- /dev/null Mon Jan 10 00:08:22 2000 +++ include/linux/module.mak Sun Apr 16 21:02:45 2000 @@ -0,0 +1,114 @@ +KERNELRELEASE = $(VERSION).$(PATCHLEVEL).$(SUBLEVEL)$(EXTRAVERSION) + +.PHONY: dummy + +ALL_OBJS = $(M_OBJS) $(MX_OBJS) +ifdef M_TARGET +I_OBJ = $(M_TARGET) +else +I_OBJ = $(ALL_OBJS) +endif + +# Generate dependencies first if necessary + +ifeq (.depend, $(wildcard .depend)) +all modules: modules_compile +include .depend +else +all modules: + $(MAKE) depend + $(MAKE) modules_compile +endif + +dep fastdep depend:: .depend + +.depend: $(wildcard *.[hc]) + @$(CC) $(CFLAGS) -M $(ALL_OBJS:.o=.c) > .tmp + @for i in $(SYMTAB_OBJS); do echo CFLAGS_$$i += -DEXPORT_SYMTAB; done >> .tmp + @mv -f .tmp .depend + +# Compilation targets + +modules_compile: check_compiler_version $(I_OBJ) + +modules_install: modules + @( \ + if [ "$(MOD_GROUP)" ]; then \ + MODLIB=$(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)/$(MOD_GROUP);\ + else \ + MODLIB=$(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)/misc;\ + fi; \ + echo Installing modules under $$MODLIB; \ + mkdir -p $$MODLIB; \ + cp $(I_OBJ) $$MODLIB; \ + ) + +check_compiler_version: + @if [ "`$(CC) -v 2>&1 | tail -1`" != $(LINUX_COMPILER) ]; \ + then echo WARNING: compiler mismatch; \ + fi + +dummy $(M_TARGET): $(ALL_OBJS) + $(LD) -r -o $(M_TARGET) $(ALL_OBJS) + +%.s: %.c + $(CC) $(PRE_CFLAGS) $(CFLAGS) $(EXTRA_CFLAGS) $(CFLAGS_$@) -S $< -o $@ + +%.i: %.c + $(CC) $(PRE_CFLAGS) $(CFLAGS) $(EXTRA_CFLAGS) $(CFLAGS_$@) -E $< > $@ + +%.o: %.c + $(CC) $(PRE_CFLAGS) $(CFLAGS) $(EXTRA_CFLAGS) $(CFLAGS_$@) -c -o $@ $< + +%.o: %.S + $(CC) $(PRE_CFLAGS) $(CFLAGS) $(EXTRA_CFLAGS) $(CFLAGS_$@) -c -o $@ $< + +# Update the symbol version tables + +SYMTAB_OBJS = $(MX_OBJS) + +ifdef CONFIG_MODVERSIONS +ifneq "$(strip $(SYMTAB_OBJS))" "" + +MODINCL = $(KINCDIR)/linux/modules + +ifdef CONFIG_SMP + genksyms_smp_prefix := -p smp_ +else + genksyms_smp_prefix := +endif + +$(MODINCL)/%.ver: %.c + @if [ ! -r $(MODINCL)/$*.stamp -o $(MODINCL)/$*.stamp -ot $< ]; then \ + echo '$(CC) $(CFLAGS) -E -D__GENKSYMS__ $<'; \ + echo '| $(GENKSYMS) $(genksyms_smp_prefix) -k $(VERSION).$(PATCHLEVEL).$(SUBLEVEL) > $@.tmp'; \ + $(CC) $(CFLAGS) -E -D__GENKSYMS__ $< \ + | $(GENKSYMS) $(genksyms_smp_prefix) -k $(VERSION).$(PATCHLEVEL).$(SUBLEVEL) > $@.tmp; \ + if [ -r $@ ] && cmp -s $@ $@.tmp; then echo $@ is unchanged; rm -f $@.tmp; \ + else echo mv $@.tmp $@; mv -f $@.tmp $@; fi; \ + fi; touch $(MODINCL)/$*.stamp + +$(addprefix $(MODINCL)/,$(SYMTAB_OBJS:.o=.ver)): $(KINCDIR)/linux/autoconf.h + +$(KINCDIR)/linux/modversions.h: $(addprefix $(MODINCL)/,$(SYMTAB_OBJS:.o=.ver)) + @echo updating $(KINCDIR)/linux/modversions.h + @(echo "#ifndef _LINUX_MODVERSIONS_H";\ + echo "#define _LINUX_MODVERSIONS_H"; \ + echo "#include <linux/modsetver.h>"; \ + cd $(KINCDIR)/linux/modules; \ + for f in *.ver; do \ + if [ -f $$f ]; then echo "#include <linux/modules/$${f}>"; fi; \ + done; \ + echo "#endif"; \ + ) > $@ + +dep fastdep depend:: $(KINCDIR)/linux/modversions.h + +endif +endif + +# Clean + +clean mrproper:: + -rm -f *.o *.a .depend + - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/