blob: 952fff4855467fb9cadeea2c767ffe902f9e9c0e [file] [log] [blame]
# SPDX-License-Identifier: GPL-2.0
# ===========================================================================
# 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, listing the name of the preliminary <module>.o file,
# plus all .o files
# d) modules.order, which lists all the modules
# Stage 2 is handled by this file and does the following
# 1) Find all modules listed in modules.order
# 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
# 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
# - 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
include include/config/auto.conf
include scripts/Kbuild.include
kernelsymfile := $(objtree)/Module.symvers
modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
MODPOST = scripts/mod/modpost \
$(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \
$(if $(KBUILD_EXTMOD),-I $(modulesymfile)) \
$(if $(KBUILD_EXTMOD),$(addprefix -e ,$(KBUILD_EXTRA_SYMBOLS))) \
$(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \
$(if $(filter nsdeps,$(MAKECMDGOALS)),-d)
quiet_cmd_modpost = MODPOST vmlinux.o
cmd_modpost = $(MODPOST) vmlinux.o
$(call cmd,modpost)
# When building external modules load the Kbuild file to retrieve EXTRA_SYMBOLS info
ifneq ($(KBUILD_EXTMOD),)
# set src + obj - they may be used when building the .mod.c file
src := $(obj)
# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
MODPOST += $(subst -i,-n,$(filter -i,$(MAKEFLAGS))) -s -T - $(wildcard vmlinux)
# find all modules listed in modules.order
modules := $(sort $(shell cat $(MODORDER)))
# Read out modules.order instead of expanding $(modules) to pass in modpost.
# Otherwise, allmodconfig would fail with "Argument list too long".
quiet_cmd_modpost = MODPOST $(words $(modules)) modules
cmd_modpost = sed 's/ko$$/o/' $(MODORDER) | $(MODPOST)
@$(kecho) ' Building modules, stage 2.'
$(call cmd,modpost)
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
nsdeps: __modpost