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 $(MODVERDIR)/ 13# 2) modpost is then used to 14# 3) create one <module>.mod.c file pr. module 15# 4) create one Module.symvers file with CRC for all exported symbols 16# 4a) [CONFIG_MARKERS] create one Module.markers file listing defined markers 17# 5) compile all <module>.mod.c files 18# 6) final link of the module to a <module.ko> file 19 20# Step 3 is used to place certain information in the module's ELF 21# section, including information such as: 22# Version magic (see include/vermagic.h for full details) 23# - Kernel release 24# - SMP is CONFIG_SMP 25# - PREEMPT is CONFIG_PREEMPT 26# - GCC Version 27# Module info 28# - Module version (MODULE_VERSION) 29# - Module alias'es (MODULE_ALIAS) 30# - Module license (MODULE_LICENSE) 31# - See include/linux/module.h for more details 32 33# Step 4 is solely used to allow module versioning in external modules, 34# where the CRC of each module is retrieved from the Module.symers file. 35 36# KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined 37# symbols in the final module linking stage 38# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules. 39# This is solely usefull to speed up test compiles 40PHONY := _modpost 41_modpost: __modpost 42 43include include/config/auto.conf 44include scripts/Kbuild.include 45 46# When building external modules load the Kbuild file to retreive EXTRA_SYMBOLS info 47ifneq ($(KBUILD_EXTMOD),) 48 49# set src + obj - they may be used when building the .mod.c file 50obj := $(KBUILD_EXTMOD) 51src := $(obj) 52 53# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS 54include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \ 55 $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile) 56endif 57 58include scripts/Makefile.lib 59 60kernelsymfile := $(objtree)/Module.symvers 61modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers 62kernelmarkersfile := $(objtree)/Module.markers 63modulemarkersfile := $(firstword $(KBUILD_EXTMOD))/Module.markers 64 65markersfile = $(if $(KBUILD_EXTMOD),$(modulemarkersfile),$(kernelmarkersfile)) 66 67# Step 1), find all modules listed in $(MODVERDIR)/ 68__modules := $(sort $(shell grep -h '\.ko' /dev/null $(wildcard $(MODVERDIR)/*.mod))) 69modules := $(patsubst %.o,%.ko, $(wildcard $(__modules:.ko=.o))) 70 71# Stop after building .o files if NOFINAL is set. Makes compile tests quicker 72_modpost: $(if $(KBUILD_MODPOST_NOFINAL), $(modules:.ko:.o),$(modules)) 73 74ifneq ($(KBUILD_BUILDHOST),$(ARCH)) 75 cross_build := 1 76endif 77 78# Step 2), invoke modpost 79# Includes step 3,4 80modpost = scripts/mod/modpost \ 81 $(if $(CONFIG_MODVERSIONS),-m) \ 82 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a,) \ 83 $(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \ 84 $(if $(KBUILD_EXTMOD),-I $(modulesymfile)) \ 85 $(if $(KBUILD_EXTRA_SYMBOLS), $(patsubst %, -e %,$(KBUILD_EXTRA_SYMBOLS))) \ 86 $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \ 87 $(if $(CONFIG_DEBUG_SECTION_MISMATCH),,-S) \ 88 $(if $(CONFIG_MARKERS),-K $(kernelmarkersfile)) \ 89 $(if $(CONFIG_MARKERS),-M $(markersfile)) \ 90 $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w) \ 91 $(if $(cross_build),-c) 92 93quiet_cmd_modpost = MODPOST $(words $(filter-out vmlinux FORCE, $^)) modules 94 cmd_modpost = $(modpost) -s 95 96PHONY += __modpost 97__modpost: $(modules:.ko=.o) FORCE 98 $(call cmd,modpost) $(wildcard vmlinux) $(filter-out FORCE,$^) 99 100quiet_cmd_kernel-mod = MODPOST $@ 101 cmd_kernel-mod = $(modpost) $@ 102 103vmlinux.o: FORCE 104 @rm -fr $(kernelmarkersfile) 105 $(call cmd,kernel-mod) 106 107# Declare generated files as targets for modpost 108$(symverfile): __modpost ; 109$(modules:.ko=.mod.c): __modpost ; 110 111ifdef CONFIG_MARKERS 112$(markersfile): __modpost ; 113endif 114 115 116# Step 5), compile all *.mod.c files 117 118# modname is set to make c_flags define KBUILD_MODNAME 119modname = $(notdir $(@:.mod.o=)) 120 121quiet_cmd_cc_o_c = CC $@ 122 cmd_cc_o_c = $(CC) $(c_flags) $(CFLAGS_MODULE) \ 123 -c -o $@ $< 124 125$(modules:.ko=.mod.o): %.mod.o: %.mod.c FORCE 126 $(call if_changed_dep,cc_o_c) 127 128targets += $(modules:.ko=.mod.o) 129 130# Step 6), final link of the modules 131quiet_cmd_ld_ko_o = LD [M] $@ 132 cmd_ld_ko_o = $(LD) -r $(LDFLAGS) $(LDFLAGS_MODULE) -o $@ \ 133 $(filter-out FORCE,$^) 134 135$(modules): %.ko :%.o %.mod.o FORCE 136 $(call if_changed,ld_ko_o) 137 138targets += $(modules) 139 140 141# Add FORCE to the prequisites of a target to force it to be always rebuilt. 142# --------------------------------------------------------------------------- 143 144PHONY += FORCE 145 146FORCE: 147 148# Read all saved command lines and dependencies for the $(targets) we 149# may be building above, using $(if_changed{,_dep}). As an 150# optimization, we don't need to read them if the target does not 151# exist, we will rebuild anyway in that case. 152 153targets := $(wildcard $(sort $(targets))) 154cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) 155 156ifneq ($(cmd_files),) 157 include $(cmd_files) 158endif 159 160 161# Declare the contents of the .PHONY variable as phony. We keep that 162# information in a variable se we can use it in if_changed and friends. 163 164.PHONY: $(PHONY) 165