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 kernelsymfile := $(objtree)/Module.symvers
47 modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
49 MODPOST = scripts/mod/modpost \
50 $(if $(CONFIG_MODVERSIONS),-m) \
51 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \
52 $(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \
53 $(if $(KBUILD_EXTMOD),$(addprefix -e ,$(KBUILD_EXTRA_SYMBOLS))) \
54 $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \
55 $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \
56 $(if $(KBUILD_MODPOST_WARN),-w)
60 quiet_cmd_modpost = MODPOST vmlinux.o
61 cmd_modpost = $(MODPOST) vmlinux.o
68 MODPOST += $(subst -i,-n,$(filter -i,$(MAKEFLAGS))) -s -T - \
69 $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS))
71 ifeq ($(KBUILD_EXTMOD),)
72 MODPOST += $(wildcard vmlinux)
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)
84 # find all modules listed in modules.order
85 modules := $(sort $(shell cat $(MODORDER)))
87 # Read out modules.order instead of expanding $(modules) to pass in modpost.
88 # Otherwise, allmodconfig would fail with "Argument list too long".
89 quiet_cmd_modpost = MODPOST $(words $(modules)) modules
90 cmd_modpost = sed 's/ko$$/o/' $(MODORDER) | $(MODPOST)
94 ifneq ($(KBUILD_MODPOST_NOFINAL),1)
95 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal