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Makefile | 2009-09-09 | 5.4 KB | 165 lines |
- # ===========================================================================
- # Module versions
- # ===========================================================================
- #
- # Stage one of module building created the following:
- # a) The individual .o files used for the module
- # b) A <module>.o file which is the .o files above linked together
- # c) A <module>.mod file in $(MODVERDIR)/, listing the name of the
- # the preliminary <module>.o file, plus all .o files
-
- # Stage 2 is handled by this file and does the following
- # 1) Find all modules from the files listed in $(MODVERDIR)/
- # 2) modpost is then used to
- # 3) create one <module>.mod.c file pr. module
- # 4) create one Module.symvers file with CRC for all exported symbols
- # 4a) [CONFIG_MARKERS] create one Module.markers file listing defined markers
- # 5) compile all <module>.mod.c files
- # 6) final link of the module to a <module.ko> file
-
- # Step 3 is used to place certain information in the module's ELF
- # section, including information such as:
- # Version magic (see include/vermagic.h for full details)
- # - Kernel release
- # - SMP is CONFIG_SMP
- # - PREEMPT is CONFIG_PREEMPT
- # - GCC Version
- # Module info
- # - Module version (MODULE_VERSION)
- # - Module alias'es (MODULE_ALIAS)
- # - Module license (MODULE_LICENSE)
- # - See include/linux/module.h for more details
-
- # Step 4 is solely used to allow module versioning in external modules,
- # where the CRC of each module is retrieved from the Module.symers file.
-
- # KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined
- # symbols in the final module linking stage
- # KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
- # This is solely usefull to speed up test compiles
- PHONY := _modpost
- _modpost: __modpost
-
- include include/config/auto.conf
- include scripts/Kbuild.include
-
- # When building external modules load the Kbuild file to retreive EXTRA_SYMBOLS info
- ifneq ($(KBUILD_EXTMOD),)
-
- # set src + obj - they may be used when building the .mod.c file
- obj := $(KBUILD_EXTMOD)
- src := $(obj)
-
- # Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
- include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
- $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
- endif
-
- include scripts/Makefile.lib
-
- kernelsymfile := $(objtree)/Module.symvers
- modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
- kernelmarkersfile := $(objtree)/Module.markers
- modulemarkersfile := $(firstword $(KBUILD_EXTMOD))/Module.markers
-
- markersfile = $(if $(KBUILD_EXTMOD),$(modulemarkersfile),$(kernelmarkersfile))
-
- # Step 1), find all modules listed in $(MODVERDIR)/
- __modules := $(sort $(shell grep -h '\.ko' /dev/null $(wildcard $(MODVERDIR)/*.mod)))
- modules := $(patsubst %.o,%.ko, $(wildcard $(__modules:.ko=.o)))
-
- # Stop after building .o files if NOFINAL is set. Makes compile tests quicker
- _modpost: $(if $(KBUILD_MODPOST_NOFINAL), $(modules:.ko:.o),$(modules))
-
- ifneq ($(KBUILD_BUILDHOST),$(ARCH))
- cross_build := 1
- endif
-
- # Step 2), invoke modpost
- # Includes step 3,4
- modpost = scripts/mod/modpost \
- $(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), $(patsubst %, -e %,$(KBUILD_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)
-
- quiet_cmd_modpost = MODPOST $(words $(filter-out vmlinux FORCE, $^)) modules
- cmd_modpost = $(modpost) -s
-
- PHONY += __modpost
- __modpost: $(modules:.ko=.o) FORCE
- $(call cmd,modpost) $(wildcard vmlinux) $(filter-out FORCE,$^)
-
- quiet_cmd_kernel-mod = MODPOST $@
- cmd_kernel-mod = $(modpost) $@
-
- vmlinux.o: FORCE
- @rm -fr $(kernelmarkersfile)
- $(call cmd,kernel-mod)
-
- # Declare generated files as targets for modpost
- $(symverfile): __modpost ;
- $(modules:.ko=.mod.c): __modpost ;
-
- ifdef CONFIG_MARKERS
- $(markersfile): __modpost ;
- endif
-
-
- # Step 5), compile all *.mod.c files
-
- # modname is set to make c_flags define KBUILD_MODNAME
- modname = $(notdir $(@:.mod.o=))
-
- quiet_cmd_cc_o_c = CC $@
- cmd_cc_o_c = $(CC) $(c_flags) $(CFLAGS_MODULE) \
- -c -o $@ $<
-
- $(modules:.ko=.mod.o): %.mod.o: %.mod.c FORCE
- $(call if_changed_dep,cc_o_c)
-
- targets += $(modules:.ko=.mod.o)
-
- # Step 6), final link of the modules
- quiet_cmd_ld_ko_o = LD [M] $@
- cmd_ld_ko_o = $(LD) -r $(LDFLAGS) $(LDFLAGS_MODULE) -o $@ \
- $(filter-out FORCE,$^)
-
- $(modules): %.ko :%.o %.mod.o FORCE
- $(call if_changed,ld_ko_o)
-
- targets += $(modules)
-
-
- # Add FORCE to the prequisites of a target to force it to be always rebuilt.
- # ---------------------------------------------------------------------------
-
- PHONY += FORCE
-
- FORCE:
-
- # Read all saved command lines and dependencies for the $(targets) we
- # may be building above, using $(if_changed{,_dep}). As an
- # optimization, we don't need to read them if the target does not
- # exist, we will rebuild anyway in that case.
-
- targets := $(wildcard $(sort $(targets)))
- cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
-
- ifneq ($(cmd_files),)
- include $(cmd_files)
- endif
-
-
- # Declare the contents of the .PHONY variable as phony. We keep that
- # information in a variable se we can use it in if_changed and friends.
-
- .PHONY: $(PHONY)
-