# ===========================================================================
# 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 $(MODVERDIR)/
+# 2) modpost is then used to
+# 3) create one <module>.mod.c file pr. module
+# 4) create one Module.symvers file with CRC for all exported symbols
+# 5) compile all <module>.mod.c files
+# 6) final link of the module to a <module.ko> file
+
+# Step 3 is used to place certain information in the module's ELF
+# section, including information such as:
+# Version magic (see include/linux/vermagic.h for full details)
+# - Kernel release
+# - SMP is CONFIG_SMP
+# - PREEMPT is CONFIG_PREEMPT
+# - GCC Version
+# Module info
+# - Module version (MODULE_VERSION)
+# - Module alias'es (MODULE_ALIAS)
+# - Module license (MODULE_LICENSE)
+# - See include/linux/module.h for more details
+
+# Step 4 is solely used to allow module versioning in external modules,
+# where the CRC of each module is retrieved from the Module.symvers file.
+
+# KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined
+# symbols in the final module linking stage
+# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
+# This is solely useful to speed up test compiles
+PHONY := _modpost
+_modpost: __modpost
+
+include include/config/auto.conf
+include scripts/Kbuild.include
+
+# When building external modules load the Kbuild file to retrieve EXTRA_SYMBOLS info
+ifneq ($(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
-.PHONY: __modversions
-__modversions:
-
-include .config
include scripts/Makefile.lib
-#
-
-__modules := $(shell cat /dev/null $(wildcard $(MODVERDIR)/*.mod))
-modules := $(patsubst %.o,%.ko,$(wildcard $(__modules:.ko=.o)))
+kernelsymfile := $(objtree)/Module.symvers
+modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
-ifneq ($(filter-out $(modules),$(__modules)),)
- $(warning *** Uh-oh, you have stale module entries. You messed with SUBDIRS,)
- $(warning do not complain if something goes wrong.)
-endif
+# 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)))
-__modversions: $(modules)
- @:
+# Stop after building .o files if NOFINAL is set. Makes compile tests quicker
+_modpost: $(if $(KBUILD_MODPOST_NOFINAL), $(modules:.ko:.o),$(modules))
-# The final module link
+ifneq ($(KBUILD_BUILDHOST),$(ARCH))
+ cross_build := 1
+endif
-quiet_cmd_ld_ko_o = LD [M] $@
- cmd_ld_ko_o = $(LD) $(LDFLAGS) $(LDFLAGS_MODULE) -o $@ \
- $(filter-out FORCE,$^)
+# 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 $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w) \
+ $(if $(cross_build),-c) \
+ $(if $(CONFIG_ENTERPRISE_SUPPORT), \
+ -N $(firstword $(wildcard $(dir $(MODVERDIR))/Module.supported \
+ $(objtree)/Module.supported \
+ $(srctree)/Module.supported /dev/null)))
+
+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
+ $(call cmd,kernel-mod)
+
+# Declare generated files as targets for modpost
+$(symverfile): __modpost ;
+$(modules:.ko=.mod.c): __modpost ;
-$(modules): %.ko :%.o %.mod.o FORCE
- $(call if_changed,ld_ko_o)
-targets += $(modules)
+# Step 5), compile all *.mod.c files
-# Compile version info for unresolved symbols
+# 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) \
+ cmd_cc_o_c = $(CC) $(c_flags) $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE) \
-c -o $@ $<
$(modules:.ko=.mod.o): %.mod.o: %.mod.c FORCE
targets += $(modules:.ko=.mod.o)
-# All the .mod.c files are generated using the helper "modpost"
-
-.PHONY: __modpost
+# Step 6), final link of the modules
+quiet_cmd_ld_ko_o = LD [M] $@
+ cmd_ld_ko_o = $(LD) -r $(LDFLAGS) \
+ $(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE) \
+ -o $@ $(filter-out FORCE,$^)
-$(modules:.ko=.mod.c): __modpost ;
+$(modules): %.ko :%.o %.mod.o FORCE
+ $(call if_changed,ld_ko_o)
-# Extract all checksums for all exported symbols
-
-# Are we building out-of-tree modules?
-
-ifeq ($(filter ../% /%,$(SUBDIRS)),)
-modver_file := modversions.$(shell echo $(CONFIG_CFGNAME))
-quiet_cmd_modpost = MODPOST
- cmd_modpost = scripts/modpost $(filter-out FORCE,$^) -o $(modver_file)
-__modpost: $(wildcard vmlinux) $(modules:.ko=.o) FORCE
- $(call if_changed,modpost)
-else
-modver_file := $(wildcard modversions.$(shell echo $(CONFIG_CFGNAME)))
-quiet_cmd_modpost = MODPOST
- cmd_modpost = scripts/modpost $^ $(if $(modver_file),-i $(modver_file))
-__modpost: $(modules:.ko=.o)
- $(call exec_cmd,modpost)
-endif
+targets += $(modules)
-targets += __modpost
# Add FORCE to the prequisites of a target to force it to be always rebuilt.
# ---------------------------------------------------------------------------
-.PHONY: FORCE
+PHONY += FORCE
FORCE:
ifneq ($(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)