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 pr. 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.
35 # KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined
36 # symbols in the final module linking stage
37 # KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
38 # This is solely useful to speed up test compiles
43 include include/config/auto.conf
44 include scripts/Kbuild.include
46 MODPOST = scripts/mod/modpost \
47 $(if $(CONFIG_MODVERSIONS),-m) \
48 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \
49 $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \
50 $(if $(KBUILD_MODPOST_WARN),-w) \
55 quiet_cmd_modpost = MODPOST $@
56 cmd_modpost = $(MODPOST) $<
58 vmlinux.symvers: vmlinux.o
61 __modpost: vmlinux.symvers
66 $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS))
68 ifeq ($(KBUILD_EXTMOD),)
70 input-symdump := vmlinux.symvers
71 output-symdump := Module.symvers
75 # set src + obj - they may be used in the modules's Makefile
76 obj := $(KBUILD_EXTMOD)
79 # Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
80 include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
81 $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
83 # modpost option for external modules
86 input-symdump := Module.symvers $(KBUILD_EXTRA_SYMBOLS)
87 output-symdump := $(KBUILD_EXTMOD)/Module.symvers
91 # modpost options for modules (both in-kernel and external)
93 $(addprefix -i ,$(wildcard $(input-symdump))) \
94 $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N)
96 # 'make -i -k' ignores compile errors, and builds as many modules as possible.
97 ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),)
101 # Clear VPATH to not search for *.symvers in $(srctree). Check only $(objtree).
104 @echo >&2 'WARNING: Symbol version dump "$@" is missing.'
105 @echo >&2 ' Modules may not have dependencies or modversions.'
107 # Read out modules.order to pass in modpost.
108 # Otherwise, allmodconfig would fail with "Argument list too long".
109 quiet_cmd_modpost = MODPOST $@
110 cmd_modpost = sed 's/ko$$/o/' $< | $(MODPOST) -T -
112 $(output-symdump): $(MODORDER) $(input-symdump) FORCE
113 $(call if_changed,modpost)
115 targets += $(output-symdump)
117 __modpost: $(output-symdump)
118 ifneq ($(KBUILD_MODPOST_NOFINAL),1)
119 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
125 existing-targets := $(wildcard $(sort $(targets)))
127 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)