summaryrefslogtreecommitdiff
path: root/scripts/Makefile.modpost
diff options
context:
space:
mode:
Diffstat (limited to 'scripts/Makefile.modpost')
-rw-r--r--scripts/Makefile.modpost110
1 files changed, 110 insertions, 0 deletions
diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
new file mode 100644
index 000000000000..94b550e21be8
--- /dev/null
+++ b/scripts/Makefile.modpost
@@ -0,0 +1,110 @@
+# ===========================================================================
+# Module versions
+# ===========================================================================
+#
+# Stage one of module building created the following:
+# a) The individual .o files used for the module
+# b) A <module>.o file wich 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/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 retreived from the Module.symers file.
+
+.PHONY: _modpost
+_modpost: __modpost
+
+include .config
+include scripts/Makefile.lib
+
+symverfile := $(objtree)/Module.symvers
+
+# 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)))
+
+_modpost: $(modules)
+
+
+# Step 2), invoke modpost
+# Includes step 3,4
+quiet_cmd_modpost = MODPOST
+ cmd_modpost = scripts/mod/modpost \
+ $(if $(CONFIG_MODVERSIONS),-m) \
+ $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a,) \
+ $(if $(KBUILD_EXTMOD),-i,-o) $(symverfile) \
+ $(filter-out FORCE,$^)
+
+.PHONY: __modpost
+__modpost: $(wildcard vmlinux) $(modules:.ko=.o) FORCE
+ $(call cmd,modpost)
+
+# Declare generated files as targets for modpost
+$(symverfile): __modpost ;
+$(modules:.ko=.mod.c): __modpost ;
+
+
+# Step 5), compile all *.mod.c files
+
+# modname is set to make c_flags define KBUILD_MODNAME
+modname = $(*F)
+
+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) $(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