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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 $(MODVERDIR)/
13# 2) modpost is then used to
14# 3) create one <module>.mod.c file pr. module
15# 4) create one Module.symvers file with CRC for all exported symbols
16# 5) compile all <module>.mod.c files
17# 6) final link of the module to a <module.ko> file
18
19# Step 3 is used to place certain information in the module's ELF
20# section, including information such as:
Geert Uytterhoeven163d3fe2011-05-25 11:09:59 +020021# Version magic (see include/linux/vermagic.h for full details)
Linus Torvalds1da177e2005-04-16 15:20:36 -070022# - Kernel release
23# - SMP is CONFIG_SMP
24# - PREEMPT is CONFIG_PREEMPT
25# - GCC Version
26# Module info
27# - Module version (MODULE_VERSION)
28# - Module alias'es (MODULE_ALIAS)
29# - Module license (MODULE_LICENSE)
30# - See include/linux/module.h for more details
31
32# Step 4 is solely used to allow module versioning in external modules,
Uwe Kleine-König4696e292010-07-30 20:43:20 +020033# where the CRC of each module is retrieved from the Module.symvers file.
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
Sam Ravnborgea837f12006-10-01 11:35:24 +020035# KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined
36# symbols in the final module linking stage
37# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
Lucas De Marchi25985ed2011-03-30 22:57:33 -030038# This is solely useful to speed up test compiles
Paul Smith4f193362006-03-05 17:14:10 -050039PHONY := _modpost
Linus Torvalds1da177e2005-04-16 15:20:36 -070040_modpost: __modpost
41
Roman Zippelc955cca2006-06-08 22:12:39 -070042include include/config/auto.conf
Sam Ravnborg8ec4b4f2005-07-25 20:10:36 +000043include scripts/Kbuild.include
Richard Hacker0d96fb22008-02-28 09:40:58 +010044
Lucas De Marchi25985ed2011-03-30 22:57:33 -030045# When building external modules load the Kbuild file to retrieve EXTRA_SYMBOLS info
Richard Hacker0d96fb22008-02-28 09:40:58 +010046ifneq ($(KBUILD_EXTMOD),)
Sam Ravnborg96d97f22008-05-31 22:28:40 +020047
48# set src + obj - they may be used when building the .mod.c file
49obj := $(KBUILD_EXTMOD)
50src := $(obj)
51
Richard Hacker0d96fb22008-02-28 09:40:58 +010052# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
53include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
54 $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
55endif
56
Linus Torvalds1da177e2005-04-16 15:20:36 -070057include scripts/Makefile.lib
58
Sam Ravnborg040fcc82006-01-28 22:15:55 +010059kernelsymfile := $(objtree)/Module.symvers
Greg Banks3f3fd3c2006-10-17 00:10:30 -070060modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
Linus Torvalds1da177e2005-04-16 15:20:36 -070061
62# Step 1), find all modules listed in $(MODVERDIR)/
63__modules := $(sort $(shell grep -h '\.ko' /dev/null $(wildcard $(MODVERDIR)/*.mod)))
64modules := $(patsubst %.o,%.ko, $(wildcard $(__modules:.ko=.o)))
65
Sam Ravnborgea837f12006-10-01 11:35:24 +020066# Stop after building .o files if NOFINAL is set. Makes compile tests quicker
67_modpost: $(if $(KBUILD_MODPOST_NOFINAL), $(modules:.ko:.o),$(modules))
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
Sam Ravnborg4ce6efe2008-03-23 21:38:54 +010069ifneq ($(KBUILD_BUILDHOST),$(ARCH))
70 cross_build := 1
71endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
73# Step 2), invoke modpost
74# Includes step 3,4
Sam Ravnborg8d8d8282007-07-20 22:36:56 +020075modpost = scripts/mod/modpost \
76 $(if $(CONFIG_MODVERSIONS),-m) \
77 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a,) \
78 $(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \
79 $(if $(KBUILD_EXTMOD),-I $(modulesymfile)) \
Peter Volkov92f83cc2008-10-25 15:02:52 -070080 $(if $(KBUILD_EXTRA_SYMBOLS), $(patsubst %, -e %,$(KBUILD_EXTRA_SYMBOLS))) \
Sam Ravnborg8d8d8282007-07-20 22:36:56 +020081 $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \
Sam Ravnborg588ccd72008-01-24 21:12:37 +010082 $(if $(CONFIG_DEBUG_SECTION_MISMATCH),,-S) \
Sam Ravnborg4ce6efe2008-03-23 21:38:54 +010083 $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w) \
84 $(if $(cross_build),-c)
Sam Ravnborg8d8d8282007-07-20 22:36:56 +020085
Sam Ravnborg12715d22006-08-08 20:43:39 +020086quiet_cmd_modpost = MODPOST $(words $(filter-out vmlinux FORCE, $^)) modules
Sam Ravnborg8d8d8282007-07-20 22:36:56 +020087 cmd_modpost = $(modpost) -s
Linus Torvalds1da177e2005-04-16 15:20:36 -070088
Paul Smith4f193362006-03-05 17:14:10 -050089PHONY += __modpost
Sam Ravnborg12715d22006-08-08 20:43:39 +020090__modpost: $(modules:.ko=.o) FORCE
Sam Ravnborg85bd2fd2007-02-26 15:33:52 +010091 $(call cmd,modpost) $(wildcard vmlinux) $(filter-out FORCE,$^)
Linus Torvalds1da177e2005-04-16 15:20:36 -070092
Sam Ravnborg12715d22006-08-08 20:43:39 +020093quiet_cmd_kernel-mod = MODPOST $@
Sam Ravnborg8d8d8282007-07-20 22:36:56 +020094 cmd_kernel-mod = $(modpost) $@
Sam Ravnborg12715d22006-08-08 20:43:39 +020095
Sam Ravnborg741f98f2007-07-17 10:54:06 +020096vmlinux.o: FORCE
Sam Ravnborg12715d22006-08-08 20:43:39 +020097 $(call cmd,kernel-mod)
98
Linus Torvalds1da177e2005-04-16 15:20:36 -070099# Declare generated files as targets for modpost
100$(symverfile): __modpost ;
101$(modules:.ko=.mod.c): __modpost ;
102
103
104# Step 5), compile all *.mod.c files
105
106# modname is set to make c_flags define KBUILD_MODNAME
Sam Ravnborg5e8d7802006-07-01 09:58:02 +0200107modname = $(notdir $(@:.mod.o=))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108
109quiet_cmd_cc_o_c = CC $@
Sam Ravnborg65881692010-07-28 17:33:09 +0200110 cmd_cc_o_c = $(CC) $(c_flags) $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 -c -o $@ $<
112
113$(modules:.ko=.mod.o): %.mod.o: %.mod.c FORCE
114 $(call if_changed_dep,cc_o_c)
115
116targets += $(modules:.ko=.mod.o)
117
118# Step 6), final link of the modules
119quiet_cmd_ld_ko_o = LD [M] $@
Sam Ravnborg65881692010-07-28 17:33:09 +0200120 cmd_ld_ko_o = $(LD) -r $(LDFLAGS) \
121 $(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE) \
122 -o $@ $(filter-out FORCE,$^)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123
124$(modules): %.ko :%.o %.mod.o FORCE
125 $(call if_changed,ld_ko_o)
126
127targets += $(modules)
128
129
130# Add FORCE to the prequisites of a target to force it to be always rebuilt.
131# ---------------------------------------------------------------------------
132
Paul Smith4f193362006-03-05 17:14:10 -0500133PHONY += FORCE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
135FORCE:
136
137# Read all saved command lines and dependencies for the $(targets) we
138# may be building above, using $(if_changed{,_dep}). As an
139# optimization, we don't need to read them if the target does not
140# exist, we will rebuild anyway in that case.
141
142targets := $(wildcard $(sort $(targets)))
143cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
144
145ifneq ($(cmd_files),)
146 include $(cmd_files)
147endif
Paul Smith4f193362006-03-05 17:14:10 -0500148
149
150# Declare the contents of the .PHONY variable as phony. We keep that
151# information in a variable se we can use it in if_changed and friends.
152
153.PHONY: $(PHONY)