1 # SPDX-License-Identifier: GPL-2.0
2 # ===========================================================================
4 # ===========================================================================
6 # Stage one of module building created the following:
7 # a) The individual .o files used for the module
8 # b) A <module>.o file which is the .o files above linked together
9 # c) A <module>.mod file, listing the name of the preliminary <module>.o file,
11 # d) modules.order, which lists all the modules
13 # Stage 2 is handled by this file and does the following
14 # 1) Find all modules listed in modules.order
15 # 2) modpost is then used to
16 # 3) create one <module>.mod.c file per module
17 # 4) create one Module.symvers file with CRC for all exported symbols
19 # Step 3 is used to place certain information in the module's ELF
20 # section, including information such as:
21 # Version magic (see include/linux/vermagic.h for full details)
24 # - PREEMPT is CONFIG_PREEMPT[_RT]
27 # - Module version (MODULE_VERSION)
28 # - Module alias'es (MODULE_ALIAS)
29 # - Module license (MODULE_LICENSE)
30 # - See include/linux/module.h for more details
32 # Step 4 is solely used to allow module versioning in external modules,
33 # where the CRC of each module is retrieved from the Module.symvers file.
38 include include/config/auto.conf
39 include $(srctree)/scripts/Kbuild.include
42 $(if $(CONFIG_MODVERSIONS),-m) \
43 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \
44 $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \
45 $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \
46 $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N) \
47 $(if $(findstring 1, $(KBUILD_EXTRA_WARN)),-W) \
50 # 'make -i -k' ignores compile errors, and builds as many modules as possible.
51 ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),)
55 ifeq ($(KBUILD_EXTMOD),)
57 # Generate the list of in-tree objects in vmlinux
58 # ---------------------------------------------------------------------------
60 # This is used to retrieve symbol versions generated by genksyms.
61 ifdef CONFIG_MODVERSIONS
62 vmlinux.symvers Module.symvers: .vmlinux.objs
66 # Some architectures do '$(CC) --print-libgcc-file-name' to borrow libgcc.a
67 # from the toolchain, but there is no EXPORT_SYMBOL in it.
69 quiet_cmd_vmlinux_objs = GEN $@
71 for f in $(real-prereqs); do \
78 targets += .vmlinux.objs
79 .vmlinux.objs: vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
80 $(call if_changed,vmlinux_objs)
82 vmlinux.o-if-present := $(wildcard vmlinux.o)
83 output-symdump := vmlinux.symvers
86 output-symdump := $(if $(vmlinux.o-if-present), Module.symvers, modules-only.symvers)
87 missing-input := $(filter-out $(vmlinux.o-if-present),vmlinux.o)
92 # set src + obj - they may be used in the modules's Makefile
93 obj := $(KBUILD_EXTMOD)
96 # Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
97 include $(or $(wildcard $(src)/Kbuild), $(src)/Makefile)
99 module.symvers-if-present := $(wildcard Module.symvers)
100 output-symdump := $(KBUILD_EXTMOD)/Module.symvers
101 missing-input := $(filter-out $(module.symvers-if-present), Module.symvers)
103 modpost-args += -e $(addprefix -i ,$(module.symvers-if-present) $(KBUILD_EXTRA_SYMBOLS))
105 endif # ($(KBUILD_EXTMOD),)
107 ifneq ($(KBUILD_MODPOST_WARN)$(missing-input),)
111 modorder-if-needed := $(if $(KBUILD_MODULES), $(MODORDER))
113 MODPOST = scripts/mod/modpost
115 # Read out modules.order to pass in modpost.
116 # Otherwise, allmodconfig would fail with "Argument list too long".
117 quiet_cmd_modpost = MODPOST $@
119 $(if $(missing-input), \
120 echo >&2 "WARNING: $(missing-input) is missing."; \
121 echo >&2 " Modules may not have dependencies or modversions."; \
122 echo >&2 " You may get many unresolved symbol warnings.";) \
123 sed 's/ko$$/o/' $(or $(modorder-if-needed), /dev/null) | $(MODPOST) $(modpost-args) -T - $(vmlinux.o-if-present)
125 targets += $(output-symdump)
126 $(output-symdump): $(modorder-if-needed) $(vmlinux.o-if-present) $(module.symvers-if-present) $(MODPOST) FORCE
127 $(call if_changed,modpost)
129 __modpost: $(output-symdump)
133 existing-targets := $(wildcard $(sort $(targets)))
135 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)