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# 5) compile all <module>.mod.c files 17# 6) final link of the module to a <module.ko> file 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/vermagic.h for full details) 22# - Kernel release 23# - SMP is CONFIG_SMP 24# - PREEMPT is CONFIG_PREEMPT 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.symers file. 34 35PHONY := _modpost 36_modpost: __modpost 37 38include include/config/auto.conf 39include scripts/Kbuild.include 40include scripts/Makefile.lib 41 42kernelsymfile := $(objtree)/Module.symvers 43modulesymfile := $(KBUILD_EXTMOD)/Module.symvers 44 45# Step 1), find all modules listed in $(MODVERDIR)/ 46__modules := $(sort $(shell grep -h '\.ko' /dev/null $(wildcard $(MODVERDIR)/*.mod))) 47modules := $(patsubst %.o,%.ko, $(wildcard $(__modules:.ko=.o))) 48 49_modpost: $(modules) 50 51 52# Step 2), invoke modpost 53# Includes step 3,4 54quiet_cmd_modpost = MODPOST $(words $(filter-out vmlinux FORCE, $^)) modules 55 cmd_modpost = scripts/mod/modpost \ 56 $(if $(CONFIG_MODVERSIONS),-m) \ 57 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a,) \ 58 $(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \ 59 $(if $(KBUILD_EXTMOD),-I $(modulesymfile)) \ 60 $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \ 61 $(if $(KBUILD_EXTMOD),-w) \ 62 $(wildcard vmlinux) $(filter-out FORCE,$^) 63 64PHONY += __modpost 65__modpost: $(modules:.ko=.o) FORCE 66 $(call cmd,modpost) 67 68quiet_cmd_kernel-mod = MODPOST $@ 69 cmd_kernel-mod = $(cmd_modpost) 70 71vmlinux: FORCE 72 $(call cmd,kernel-mod) 73 74# Declare generated files as targets for modpost 75$(symverfile): __modpost ; 76$(modules:.ko=.mod.c): __modpost ; 77 78 79# Step 5), compile all *.mod.c files 80 81# modname is set to make c_flags define KBUILD_MODNAME 82modname = $(notdir $(@:.mod.o=)) 83 84quiet_cmd_cc_o_c = CC $@ 85 cmd_cc_o_c = $(CC) $(c_flags) $(CFLAGS_MODULE) \ 86 -c -o $@ $< 87 88$(modules:.ko=.mod.o): %.mod.o: %.mod.c FORCE 89 $(call if_changed_dep,cc_o_c) 90 91targets += $(modules:.ko=.mod.o) 92 93# Step 6), final link of the modules 94quiet_cmd_ld_ko_o = LD [M] $@ 95 cmd_ld_ko_o = $(LD) $(LDFLAGS) $(LDFLAGS_MODULE) -o $@ \ 96 $(filter-out FORCE,$^) 97 98$(modules): %.ko :%.o %.mod.o FORCE 99 $(call if_changed,ld_ko_o) 100 101targets += $(modules) 102 103 104# Add FORCE to the prequisites of a target to force it to be always rebuilt. 105# --------------------------------------------------------------------------- 106 107PHONY += FORCE 108 109FORCE: 110 111# Read all saved command lines and dependencies for the $(targets) we 112# may be building above, using $(if_changed{,_dep}). As an 113# optimization, we don't need to read them if the target does not 114# exist, we will rebuild anyway in that case. 115 116targets := $(wildcard $(sort $(targets))) 117cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) 118 119ifneq ($(cmd_files),) 120 include $(cmd_files) 121endif 122 123 124# Declare the contents of the .PHONY variable as phony. We keep that 125# information in a variable se we can use it in if_changed and friends. 126 127.PHONY: $(PHONY) 128