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Linus Torvalds1da177e2005-04-16 15:20:36 -07001# ===========================================================================
2# Module versions
3# ===========================================================================
4#
5# Stage one of module building created the following:
6# a) The individual .o files used for the module
Uwe Zeisbergerc30fe7f2006-03-24 18:23:14 +01007# b) A <module>.o file which is the .o files above linked together
Linus Torvalds1da177e2005-04-16 15:20:36 -07008# 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,
Adrian Bunk943ffb52006-01-10 00:10:13 +010033# where the CRC of each module is retrieved from the Module.symers file.
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
Sam Ravnborgea837f12006-10-01 11:35:24 +020035# 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 usefull to speed up test compiles
Paul Smith4f193362006-03-05 17:14:10 -050039PHONY := _modpost
Linus Torvalds1da177e2005-04-16 15:20:36 -070040_modpost: __modpost
41
Roman Zippelc955cca2006-06-08 22:12:39 -070042include include/config/auto.conf
Sam Ravnborg8ec4b4f2005-07-25 20:10:36 +000043include scripts/Kbuild.include
Linus Torvalds1da177e2005-04-16 15:20:36 -070044include scripts/Makefile.lib
45
Sam Ravnborg040fcc82006-01-28 22:15:55 +010046kernelsymfile := $(objtree)/Module.symvers
Greg Banks3f3fd3c2006-10-17 00:10:30 -070047modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
Linus Torvalds1da177e2005-04-16 15:20:36 -070048
49# Step 1), find all modules listed in $(MODVERDIR)/
50__modules := $(sort $(shell grep -h '\.ko' /dev/null $(wildcard $(MODVERDIR)/*.mod)))
51modules := $(patsubst %.o,%.ko, $(wildcard $(__modules:.ko=.o)))
52
Sam Ravnborgea837f12006-10-01 11:35:24 +020053# Stop after building .o files if NOFINAL is set. Makes compile tests quicker
54_modpost: $(if $(KBUILD_MODPOST_NOFINAL), $(modules:.ko:.o),$(modules))
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
56
57# Step 2), invoke modpost
58# Includes step 3,4
Sam Ravnborg8d8d8282007-07-20 22:36:56 +020059modpost = scripts/mod/modpost \
60 $(if $(CONFIG_MODVERSIONS),-m) \
61 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a,) \
62 $(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \
63 $(if $(KBUILD_EXTMOD),-I $(modulesymfile)) \
64 $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \
65 $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w)
66
Sam Ravnborg12715d22006-08-08 20:43:39 +020067quiet_cmd_modpost = MODPOST $(words $(filter-out vmlinux FORCE, $^)) modules
Sam Ravnborg8d8d8282007-07-20 22:36:56 +020068 cmd_modpost = $(modpost) -s
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
Paul Smith4f193362006-03-05 17:14:10 -050070PHONY += __modpost
Sam Ravnborg12715d22006-08-08 20:43:39 +020071__modpost: $(modules:.ko=.o) FORCE
Sam Ravnborg85bd2fd2007-02-26 15:33:52 +010072 $(call cmd,modpost) $(wildcard vmlinux) $(filter-out FORCE,$^)
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
Sam Ravnborg12715d22006-08-08 20:43:39 +020074quiet_cmd_kernel-mod = MODPOST $@
Sam Ravnborg8d8d8282007-07-20 22:36:56 +020075 cmd_kernel-mod = $(modpost) $@
Sam Ravnborg12715d22006-08-08 20:43:39 +020076
Sam Ravnborg741f98f2007-07-17 10:54:06 +020077vmlinux.o: FORCE
Sam Ravnborg12715d22006-08-08 20:43:39 +020078 $(call cmd,kernel-mod)
79
Linus Torvalds1da177e2005-04-16 15:20:36 -070080# Declare generated files as targets for modpost
81$(symverfile): __modpost ;
82$(modules:.ko=.mod.c): __modpost ;
83
84
85# Step 5), compile all *.mod.c files
86
87# modname is set to make c_flags define KBUILD_MODNAME
Sam Ravnborg5e8d7802006-07-01 09:58:02 +020088modname = $(notdir $(@:.mod.o=))
Linus Torvalds1da177e2005-04-16 15:20:36 -070089
90quiet_cmd_cc_o_c = CC $@
91 cmd_cc_o_c = $(CC) $(c_flags) $(CFLAGS_MODULE) \
92 -c -o $@ $<
93
94$(modules:.ko=.mod.o): %.mod.o: %.mod.c FORCE
95 $(call if_changed_dep,cc_o_c)
96
97targets += $(modules:.ko=.mod.o)
98
99# Step 6), final link of the modules
100quiet_cmd_ld_ko_o = LD [M] $@
Sam Ravnborgea837f12006-10-01 11:35:24 +0200101 cmd_ld_ko_o = $(LD) $(LDFLAGS) $(LDFLAGS_MODULE) -o $@ \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 $(filter-out FORCE,$^)
103
104$(modules): %.ko :%.o %.mod.o FORCE
105 $(call if_changed,ld_ko_o)
106
107targets += $(modules)
108
109
110# Add FORCE to the prequisites of a target to force it to be always rebuilt.
111# ---------------------------------------------------------------------------
112
Paul Smith4f193362006-03-05 17:14:10 -0500113PHONY += FORCE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
115FORCE:
116
117# Read all saved command lines and dependencies for the $(targets) we
118# may be building above, using $(if_changed{,_dep}). As an
119# optimization, we don't need to read them if the target does not
120# exist, we will rebuild anyway in that case.
121
122targets := $(wildcard $(sort $(targets)))
123cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
124
125ifneq ($(cmd_files),)
126 include $(cmd_files)
127endif
Paul Smith4f193362006-03-05 17:14:10 -0500128
129
130# Declare the contents of the .PHONY variable as phony. We keep that
131# information in a variable se we can use it in if_changed and friends.
132
133.PHONY: $(PHONY)