1# SPDX-License-Identifier: GPL-2.0 2# =========================================================================== 3# Module versions 4# =========================================================================== 5# 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, 10# plus all .o files 11# d) modules.order, which lists all the modules 12 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 18 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) 22# - Kernel release 23# - SMP is CONFIG_SMP 24# - PREEMPT is CONFIG_PREEMPT[_RT] 25# - GCC Version 26# Module info 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 31 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. 34 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 39 40PHONY := __modpost 41__modpost: 42 43include include/config/auto.conf 44include scripts/Kbuild.include 45 46kernelsymfile := $(objtree)/Module.symvers 47modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers 48 49MODPOST = 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),-I $(modulesymfile)) \ 54 $(if $(KBUILD_EXTMOD),$(addprefix -e ,$(KBUILD_EXTRA_SYMBOLS))) \ 55 $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \ 56 $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ 57 $(if $(KBUILD_MODPOST_WARN),-w) \ 58 $(if $(filter nsdeps,$(MAKECMDGOALS)),-d) 59 60ifdef MODPOST_VMLINUX 61 62quiet_cmd_modpost = MODPOST vmlinux.o 63 cmd_modpost = $(MODPOST) vmlinux.o 64 65__modpost: 66 $(call cmd,modpost) 67 68else 69 70# When building external modules load the Kbuild file to retrieve EXTRA_SYMBOLS info 71ifneq ($(KBUILD_EXTMOD),) 72 73# set src + obj - they may be used when building the .mod.c file 74obj := $(KBUILD_EXTMOD) 75src := $(obj) 76 77# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS 78include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \ 79 $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile) 80endif 81 82MODPOST += $(subst -i,-n,$(filter -i,$(MAKEFLAGS))) -s -T - $(wildcard vmlinux) 83 84# find all modules listed in modules.order 85modules := $(sort $(shell cat $(MODORDER))) 86 87# Read out modules.order instead of expanding $(modules) to pass in modpost. 88# Otherwise, allmodconfig would fail with "Argument list too long". 89quiet_cmd_modpost = MODPOST $(words $(modules)) modules 90 cmd_modpost = sed 's/ko$$/o/' $(MODORDER) | $(MODPOST) 91 92__modpost: 93 @$(kecho) ' Building modules, stage 2.' 94 $(call cmd,modpost) 95ifneq ($(KBUILD_MODPOST_NOFINAL),1) 96 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal 97endif 98 99nsdeps: __modpost 100 101endif 102 103.PHONY: $(PHONY) 104