1# =========================================================================== 2# Module versions 3# =========================================================================== 4# 5# Stage one of module building created the following: 6# a) The individual .o files used for the module 7# b) A <module>.o file which is the .o files above linked together 8# c) A <module>.mod file in $(MODVERDIR)/, listing the name of the 9# the preliminary <module>.o file, plus all .o files 10 11# Stage 2 is handled by this file and does the following 12# 1) Find all modules from the files listed in $(MODVERDIR)/ 13# 2) modpost is then used to 14# 3) create one <module>.mod.c file pr. module 15# 4) create one Module.symvers file with CRC for all exported symbols 16# 4a) [CONFIG_MARKERS] create one Module.markers file listing defined markers 17# 5) compile all <module>.mod.c files 18# 6) final link of the module to a <module.ko> file 19 20# Step 3 is used to place certain information in the module's ELF 21# section, including information such as: 22# Version magic (see include/vermagic.h for full details) 23# - Kernel release 24# - SMP is CONFIG_SMP 25# - PREEMPT is CONFIG_PREEMPT 26# - GCC Version 27# Module info 28# - Module version (MODULE_VERSION) 29# - Module alias'es (MODULE_ALIAS) 30# - Module license (MODULE_LICENSE) 31# - See include/linux/module.h for more details 32 33# Step 4 is solely used to allow module versioning in external modules, 34# where the CRC of each module is retrieved from the Module.symers file. 35 36# KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined 37# symbols in the final module linking stage 38# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules. 39# This is solely usefull to speed up test compiles 40PHONY := _modpost 41_modpost: __modpost 42 43include include/config/auto.conf 44include scripts/Kbuild.include 45 46ifneq ($(KBUILD_EXTMOD),) 47# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS 48include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \ 49 $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile) 50endif 51 52include scripts/Makefile.lib 53 54kernelsymfile := $(objtree)/Module.symvers 55modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers 56kernelmarkersfile := $(objtree)/Module.markers 57modulemarkersfile := $(firstword $(KBUILD_EXTMOD))/Module.markers 58 59markersfile = $(if $(KBUILD_EXTMOD),$(modulemarkersfile),$(kernelmarkersfile)) 60 61# Step 1), find all modules listed in $(MODVERDIR)/ 62__modules := $(sort $(shell grep -h '\.ko' /dev/null $(wildcard $(MODVERDIR)/*.mod))) 63modules := $(patsubst %.o,%.ko, $(wildcard $(__modules:.ko=.o))) 64 65# Stop after building .o files if NOFINAL is set. Makes compile tests quicker 66_modpost: $(if $(KBUILD_MODPOST_NOFINAL), $(modules:.ko:.o),$(modules)) 67 68ifneq ($(KBUILD_BUILDHOST),$(ARCH)) 69 cross_build := 1 70endif 71 72# Step 2), invoke modpost 73# Includes step 3,4 74modpost = scripts/mod/modpost \ 75 $(if $(CONFIG_MODVERSIONS),-m) \ 76 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a,) \ 77 $(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \ 78 $(if $(KBUILD_EXTMOD),-I $(modulesymfile)) \ 79 $(if $(KBUILD_EXTRA_SYMBOLS), $(patsubst %, -e %,$(EXTRA_SYMBOLS))) \ 80 $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \ 81 $(if $(CONFIG_DEBUG_SECTION_MISMATCH),,-S) \ 82 $(if $(CONFIG_MARKERS),-K $(kernelmarkersfile)) \ 83 $(if $(CONFIG_MARKERS),-M $(markersfile)) \ 84 $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w) \ 85 $(if $(cross_build),-c) 86 87quiet_cmd_modpost = MODPOST $(words $(filter-out vmlinux FORCE, $^)) modules 88 cmd_modpost = $(modpost) -s 89 90PHONY += __modpost 91__modpost: $(modules:.ko=.o) FORCE 92 $(call cmd,modpost) $(wildcard vmlinux) $(filter-out FORCE,$^) 93 94quiet_cmd_kernel-mod = MODPOST $@ 95 cmd_kernel-mod = $(modpost) $@ 96 97vmlinux.o: FORCE 98 $(call cmd,kernel-mod) 99 100# Declare generated files as targets for modpost 101$(symverfile): __modpost ; 102$(modules:.ko=.mod.c): __modpost ; 103 104ifdef CONFIG_MARKERS 105$(markersfile): __modpost ; 106endif 107 108 109# Step 5), compile all *.mod.c files 110 111# modname is set to make c_flags define KBUILD_MODNAME 112modname = $(notdir $(@:.mod.o=)) 113 114quiet_cmd_cc_o_c = CC $@ 115 cmd_cc_o_c = $(CC) $(c_flags) $(CFLAGS_MODULE) \ 116 -c -o $@ $< 117 118$(modules:.ko=.mod.o): %.mod.o: %.mod.c FORCE 119 $(call if_changed_dep,cc_o_c) 120 121targets += $(modules:.ko=.mod.o) 122 123# Step 6), final link of the modules 124quiet_cmd_ld_ko_o = LD [M] $@ 125 cmd_ld_ko_o = $(LD) -r $(LDFLAGS) $(LDFLAGS_MODULE) -o $@ \ 126 $(filter-out FORCE,$^) 127 128$(modules): %.ko :%.o %.mod.o FORCE 129 $(call if_changed,ld_ko_o) 130 131targets += $(modules) 132 133 134# Add FORCE to the prequisites of a target to force it to be always rebuilt. 135# --------------------------------------------------------------------------- 136 137PHONY += FORCE 138 139FORCE: 140 141# Read all saved command lines and dependencies for the $(targets) we 142# may be building above, using $(if_changed{,_dep}). As an 143# optimization, we don't need to read them if the target does not 144# exist, we will rebuild anyway in that case. 145 146targets := $(wildcard $(sort $(targets))) 147cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) 148 149ifneq ($(cmd_files),) 150 include $(cmd_files) 151endif 152 153 154# Declare the contents of the .PHONY variable as phony. We keep that 155# information in a variable se we can use it in if_changed and friends. 156 157.PHONY: $(PHONY) 158