Makefile.modpost 5.5 KB

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  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. # Stage 2 is handled by this file and does the following
  11. # 1) Find all modules from the files listed in $(MODVERDIR)/
  12. # 2) modpost is then used to
  13. # 3) create one <module>.mod.c file pr. module
  14. # 4) create one Module.symvers file with CRC for all exported symbols
  15. # 5) compile all <module>.mod.c files
  16. # 6) final link of the module to a <module.ko> file
  17. # Step 3 is used to place certain information in the module's ELF
  18. # section, including information such as:
  19. # Version magic (see include/linux/vermagic.h for full details)
  20. # - Kernel release
  21. # - SMP is CONFIG_SMP
  22. # - PREEMPT is CONFIG_PREEMPT
  23. # - GCC Version
  24. # Module info
  25. # - Module version (MODULE_VERSION)
  26. # - Module alias'es (MODULE_ALIAS)
  27. # - Module license (MODULE_LICENSE)
  28. # - See include/linux/module.h for more details
  29. # Step 4 is solely used to allow module versioning in external modules,
  30. # where the CRC of each module is retrieved from the Module.symvers file.
  31. # KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined
  32. # symbols in the final module linking stage
  33. # KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
  34. # This is solely useful to speed up test compiles
  35. PHONY := _modpost
  36. _modpost: __modpost
  37. include include/config/auto.conf
  38. include scripts/Kbuild.include
  39. # When building external modules load the Kbuild file to retrieve EXTRA_SYMBOLS info
  40. ifneq ($(KBUILD_EXTMOD),)
  41. # set src + obj - they may be used when building the .mod.c file
  42. obj := $(KBUILD_EXTMOD)
  43. src := $(obj)
  44. # Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
  45. include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
  46. $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
  47. endif
  48. include scripts/Makefile.lib
  49. kernelsymfile := $(objtree)/Module.symvers
  50. modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
  51. # Step 1), find all modules listed in $(MODVERDIR)/
  52. MODLISTCMD := find $(MODVERDIR) -name '*.mod' | xargs -r grep -h '\.ko$$' | sort -u
  53. __modules := $(shell $(MODLISTCMD))
  54. modules := $(patsubst %.o,%.ko, $(wildcard $(__modules:.ko=.o)))
  55. # Stop after building .o files if NOFINAL is set. Makes compile tests quicker
  56. _modpost: $(if $(KBUILD_MODPOST_NOFINAL), $(modules:.ko:.o),$(modules))
  57. # Step 2), invoke modpost
  58. # Includes step 3,4
  59. modpost = scripts/mod/modpost \
  60. $(if $(CONFIG_MODVERSIONS),-m) \
  61. $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a,) \
  62. $(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \
  63. $(if $(KBUILD_EXTMOD),-I $(modulesymfile)) \
  64. $(if $(KBUILD_EXTRA_SYMBOLS), $(patsubst %, -e %,$(KBUILD_EXTRA_SYMBOLS))) \
  65. $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \
  66. $(if $(CONFIG_DEBUG_SECTION_MISMATCH),,-S) \
  67. $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \
  68. $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w)
  69. MODPOST_OPT=$(subst -i,-n,$(filter -i,$(MAKEFLAGS)))
  70. # We can go over command line length here, so be careful.
  71. quiet_cmd_modpost = MODPOST $(words $(filter-out vmlinux FORCE, $^)) modules
  72. cmd_modpost = $(MODLISTCMD) | sed 's/\.ko$$/.o/' | $(modpost) $(MODPOST_OPT) -s -T -
  73. PHONY += __modpost
  74. __modpost: $(modules:.ko=.o) FORCE
  75. $(call cmd,modpost) $(wildcard vmlinux)
  76. quiet_cmd_kernel-mod = MODPOST $@
  77. cmd_kernel-mod = $(modpost) $@
  78. vmlinux.o: FORCE
  79. $(call cmd,kernel-mod)
  80. # Declare generated files as targets for modpost
  81. $(symverfile): __modpost ;
  82. $(modules:.ko=.mod.c): __modpost ;
  83. # Step 5), compile all *.mod.c files
  84. # modname is set to make c_flags define KBUILD_MODNAME
  85. modname = $(notdir $(@:.mod.o=))
  86. quiet_cmd_cc_o_c = CC $@
  87. cmd_cc_o_c = $(CC) $(c_flags) $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE) \
  88. -c -o $@ $<
  89. $(modules:.ko=.mod.o): %.mod.o: %.mod.c FORCE
  90. $(call if_changed_dep,cc_o_c)
  91. targets += $(modules:.ko=.mod.o)
  92. ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
  93. # Step 6), final link of the modules with optional arch pass after final link
  94. quiet_cmd_ld_ko_o = LD [M] $@
  95. cmd_ld_ko_o = \
  96. $(LD) -r $(LDFLAGS) \
  97. $(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE) \
  98. -o $@ $(filter-out FORCE,$^) ; \
  99. $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
  100. $(modules): %.ko :%.o %.mod.o FORCE
  101. +$(call if_changed,ld_ko_o)
  102. targets += $(modules)
  103. # Add FORCE to the prequisites of a target to force it to be always rebuilt.
  104. # ---------------------------------------------------------------------------
  105. PHONY += FORCE
  106. FORCE:
  107. # Read all saved command lines and dependencies for the $(targets) we
  108. # may be building above, using $(if_changed{,_dep}). As an
  109. # optimization, we don't need to read them if the target does not
  110. # exist, we will rebuild anyway in that case.
  111. targets := $(wildcard $(sort $(targets)))
  112. cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
  113. ifneq ($(cmd_files),)
  114. include $(cmd_files)
  115. endif
  116. # Declare the contents of the .PHONY variable as phony. We keep that
  117. # information in a variable se we can use it in if_changed and friends.
  118. .PHONY: $(PHONY)