Makefile.modpost 4.3 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/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.symers 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 usefull to speed up test compiles
  35. PHONY := _modpost
  36. _modpost: __modpost
  37. include include/config/auto.conf
  38. include scripts/Kbuild.include
  39. include scripts/Makefile.lib
  40. kernelsymfile := $(objtree)/Module.symvers
  41. modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
  42. # Step 1), find all modules listed in $(MODVERDIR)/
  43. __modules := $(sort $(shell grep -h '\.ko' /dev/null $(wildcard $(MODVERDIR)/*.mod)))
  44. modules := $(patsubst %.o,%.ko, $(wildcard $(__modules:.ko=.o)))
  45. # Stop after building .o files if NOFINAL is set. Makes compile tests quicker
  46. _modpost: $(if $(KBUILD_MODPOST_NOFINAL), $(modules:.ko:.o),$(modules))
  47. # Step 2), invoke modpost
  48. # Includes step 3,4
  49. quiet_cmd_modpost = MODPOST $(words $(filter-out vmlinux FORCE, $^)) modules
  50. cmd_modpost = scripts/mod/modpost \
  51. $(if $(CONFIG_MODVERSIONS),-m) \
  52. $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a,) \
  53. $(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \
  54. $(if $(KBUILD_EXTMOD),-I $(modulesymfile)) \
  55. $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \
  56. $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w) \
  57. $(wildcard vmlinux) $(filter-out FORCE,$^)
  58. PHONY += __modpost
  59. __modpost: $(modules:.ko=.o) FORCE
  60. $(call cmd,modpost)
  61. quiet_cmd_kernel-mod = MODPOST $@
  62. cmd_kernel-mod = $(cmd_modpost)
  63. vmlinux: FORCE
  64. $(call cmd,kernel-mod)
  65. # Declare generated files as targets for modpost
  66. $(symverfile): __modpost ;
  67. $(modules:.ko=.mod.c): __modpost ;
  68. # Step 5), compile all *.mod.c files
  69. # modname is set to make c_flags define KBUILD_MODNAME
  70. modname = $(notdir $(@:.mod.o=))
  71. quiet_cmd_cc_o_c = CC $@
  72. cmd_cc_o_c = $(CC) $(c_flags) $(CFLAGS_MODULE) \
  73. -c -o $@ $<
  74. $(modules:.ko=.mod.o): %.mod.o: %.mod.c FORCE
  75. $(call if_changed_dep,cc_o_c)
  76. targets += $(modules:.ko=.mod.o)
  77. # Step 6), final link of the modules
  78. quiet_cmd_ld_ko_o = LD [M] $@
  79. cmd_ld_ko_o = $(LD) $(LDFLAGS) $(LDFLAGS_MODULE) -o $@ \
  80. $(filter-out FORCE,$^)
  81. $(modules): %.ko :%.o %.mod.o FORCE
  82. $(call if_changed,ld_ko_o)
  83. targets += $(modules)
  84. # Add FORCE to the prequisites of a target to force it to be always rebuilt.
  85. # ---------------------------------------------------------------------------
  86. PHONY += FORCE
  87. FORCE:
  88. # Read all saved command lines and dependencies for the $(targets) we
  89. # may be building above, using $(if_changed{,_dep}). As an
  90. # optimization, we don't need to read them if the target does not
  91. # exist, we will rebuild anyway in that case.
  92. targets := $(wildcard $(sort $(targets)))
  93. cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
  94. ifneq ($(cmd_files),)
  95. include $(cmd_files)
  96. endif
  97. # Declare the contents of the .PHONY variable as phony. We keep that
  98. # information in a variable se we can use it in if_changed and friends.
  99. .PHONY: $(PHONY)