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b2441318 | 1 | # SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | # =========================================================================== |
3 | # Module versions | |
4 | # =========================================================================== | |
5 | # | |
6 | # Stage one of module building created the following: | |
7 | # a) The individual .o files used for the module | |
c30fe7f7 | 8 | # b) A <module>.o file which is the .o files above linked together |
b7dca6dd MY |
9 | # c) A <module>.mod file, listing the name of the preliminary <module>.o file, |
10 | # plus all .o files | |
ff9b45c5 | 11 | # d) modules.order, which lists all the modules |
1da177e4 LT |
12 | |
13 | # Stage 2 is handled by this file and does the following | |
ff9b45c5 | 14 | # 1) Find all modules listed in modules.order |
1da177e4 LT |
15 | # 2) modpost is then used to |
16 | # 3) create one <module>.mod.c file pr. module | |
17 | # 4) create one Module.symvers file with CRC for all exported symbols | |
18 | # 5) compile all <module>.mod.c files | |
e2a666d5 | 19 | # 6) final link of the module to a <module.ko> file |
1da177e4 LT |
20 | |
21 | # Step 3 is used to place certain information in the module's ELF | |
22 | # section, including information such as: | |
163d3fe6 | 23 | # Version magic (see include/linux/vermagic.h for full details) |
1da177e4 LT |
24 | # - Kernel release |
25 | # - SMP is CONFIG_SMP | |
26 | # - PREEMPT is CONFIG_PREEMPT | |
27 | # - GCC Version | |
28 | # Module info | |
29 | # - Module version (MODULE_VERSION) | |
30 | # - Module alias'es (MODULE_ALIAS) | |
31 | # - Module license (MODULE_LICENSE) | |
32 | # - See include/linux/module.h for more details | |
33 | ||
34 | # Step 4 is solely used to allow module versioning in external modules, | |
4696e295 | 35 | # where the CRC of each module is retrieved from the Module.symvers file. |
1da177e4 | 36 | |
ea837f1c SR |
37 | # KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined |
38 | # symbols in the final module linking stage | |
39 | # KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules. | |
25985edc | 40 | # This is solely useful to speed up test compiles |
a721588d MY |
41 | |
42 | PHONY := __modpost | |
43 | __modpost: | |
1da177e4 | 44 | |
c955ccaf | 45 | include include/config/auto.conf |
8ec4b4ff | 46 | include scripts/Kbuild.include |
0d96fb20 | 47 | |
a721588d MY |
48 | kernelsymfile := $(objtree)/Module.symvers |
49 | modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers | |
50 | ||
51 | MODPOST = scripts/mod/modpost \ | |
52 | $(if $(CONFIG_MODVERSIONS),-m) \ | |
53 | $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \ | |
54 | $(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \ | |
55 | $(if $(KBUILD_EXTMOD),-I $(modulesymfile)) \ | |
56 | $(if $(KBUILD_EXTMOD),$(addprefix -e ,$(KBUILD_EXTRA_SYMBOLS))) \ | |
57 | $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \ | |
58 | $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ | |
59 | $(if $(KBUILD_MODPOST_WARN),-w) | |
60 | ||
61 | ifdef MODPOST_VMLINUX | |
62 | ||
63 | __modpost: vmlinux.o | |
64 | ||
65 | quiet_cmd_modpost = MODPOST $@ | |
66 | cmd_modpost = $(MODPOST) $@ | |
67 | ||
68 | PHONY += vmlinux.o | |
69 | vmlinux.o: | |
70 | $(call cmd,modpost) | |
71 | ||
72 | else | |
73 | ||
25985edc | 74 | # When building external modules load the Kbuild file to retrieve EXTRA_SYMBOLS info |
0d96fb20 | 75 | ifneq ($(KBUILD_EXTMOD),) |
96d97f26 SR |
76 | |
77 | # set src + obj - they may be used when building the .mod.c file | |
78 | obj := $(KBUILD_EXTMOD) | |
79 | src := $(obj) | |
80 | ||
0d96fb20 RH |
81 | # Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS |
82 | include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \ | |
83 | $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile) | |
84 | endif | |
85 | ||
1da177e4 LT |
86 | include scripts/Makefile.lib |
87 | ||
a721588d | 88 | # find all modules listed in modules.order |
47801c97 | 89 | modules := $(sort $(shell cat $(MODORDER))) |
1da177e4 | 90 | |
ea837f1c | 91 | # Stop after building .o files if NOFINAL is set. Makes compile tests quicker |
a721588d MY |
92 | __modpost: $(if $(KBUILD_MODPOST_NOFINAL), $(modules:.ko:.o),$(modules)) |
93 | @: | |
94 | ||
95 | MODPOST += $(subst -i,-n,$(filter -i,$(MAKEFLAGS))) -s -T - $(wildcard vmlinux) | |
eed380f3 | 96 | |
ea4054a2 | 97 | # We can go over command line length here, so be careful. |
acf2a139 | 98 | quiet_cmd_modpost = MODPOST $(words $(modules)) modules |
47801c97 | 99 | cmd_modpost = sed 's/ko$$/o/' $(MODORDER) | $(MODPOST) |
1da177e4 | 100 | |
a721588d MY |
101 | PHONY += modules-modpost |
102 | modules-modpost: | |
103 | $(call cmd,modpost) | |
12715d20 | 104 | |
1da177e4 | 105 | # Declare generated files as targets for modpost |
a721588d | 106 | $(modules:.ko=.mod.c): modules-modpost |
1da177e4 LT |
107 | |
108 | # Step 5), compile all *.mod.c files | |
109 | ||
110 | # modname is set to make c_flags define KBUILD_MODNAME | |
5e8d780d | 111 | modname = $(notdir $(@:.mod.o=)) |
1da177e4 LT |
112 | |
113 | quiet_cmd_cc_o_c = CC $@ | |
6588169d | 114 | cmd_cc_o_c = $(CC) $(c_flags) $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE) \ |
1da177e4 LT |
115 | -c -o $@ $< |
116 | ||
117 | $(modules:.ko=.mod.o): %.mod.o: %.mod.c FORCE | |
118 | $(call if_changed_dep,cc_o_c) | |
119 | ||
120 | targets += $(modules:.ko=.mod.o) | |
121 | ||
fbe6e37d NP |
122 | ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink) |
123 | ||
124 | # Step 6), final link of the modules with optional arch pass after final link | |
1da177e4 | 125 | quiet_cmd_ld_ko_o = LD [M] $@ |
fbe6e37d | 126 | cmd_ld_ko_o = \ |
d503ac53 | 127 | $(LD) -r $(KBUILD_LDFLAGS) \ |
fbe6e37d | 128 | $(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE) \ |
afa974b7 | 129 | -o $@ $(real-prereqs) ; \ |
fbe6e37d | 130 | $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true) |
1da177e4 LT |
131 | |
132 | $(modules): %.ko :%.o %.mod.o FORCE | |
fbe6e37d | 133 | +$(call if_changed,ld_ko_o) |
1da177e4 LT |
134 | |
135 | targets += $(modules) | |
136 | ||
137 | ||
138 | # Add FORCE to the prequisites of a target to force it to be always rebuilt. | |
139 | # --------------------------------------------------------------------------- | |
140 | ||
4f193362 | 141 | PHONY += FORCE |
1da177e4 LT |
142 | |
143 | FORCE: | |
144 | ||
145 | # Read all saved command lines and dependencies for the $(targets) we | |
146 | # may be building above, using $(if_changed{,_dep}). As an | |
147 | # optimization, we don't need to read them if the target does not | |
148 | # exist, we will rebuild anyway in that case. | |
149 | ||
944cfe9b | 150 | existing-targets := $(wildcard $(sort $(targets))) |
1da177e4 | 151 | |
944cfe9b | 152 | -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd) |
4f193362 | 153 | |
a721588d MY |
154 | endif |
155 | ||
4f193362 | 156 | .PHONY: $(PHONY) |