Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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)