Makefile.build 11 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368
  1. # ==========================================================================
  2. # Building
  3. # ==========================================================================
  4. src := $(obj)
  5. PHONY := __build
  6. __build:
  7. # Init all relevant variables used in kbuild files so
  8. # 1) they have correct type
  9. # 2) they do not inherit any value from the environment
  10. obj-y :=
  11. obj-m :=
  12. lib-y :=
  13. lib-m :=
  14. always :=
  15. targets :=
  16. subdir-y :=
  17. subdir-m :=
  18. EXTRA_AFLAGS :=
  19. EXTRA_CFLAGS :=
  20. EXTRA_CPPFLAGS :=
  21. EXTRA_LDFLAGS :=
  22. asflags-y :=
  23. ccflags-y :=
  24. cppflags-y :=
  25. ldflags-y :=
  26. # Read .config if it exist, otherwise ignore
  27. -include include/config/auto.conf
  28. include scripts/Kbuild.include
  29. # For backward compatibility check that these variables does not change
  30. save-cflags := $(CFLAGS)
  31. # The filename Kbuild has precedence over Makefile
  32. kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
  33. kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
  34. include $(kbuild-file)
  35. # If the save-* variables changed error out
  36. ifeq ($(KBUILD_NOPEDANTIC),)
  37. ifneq ("$(save-cflags)","$(CFLAGS)")
  38. $(error CFLAGS was changed in "$(kbuild-file)". Fix it to use EXTRA_CFLAGS)
  39. endif
  40. endif
  41. include scripts/Makefile.lib
  42. ifdef host-progs
  43. ifneq ($(hostprogs-y),$(host-progs))
  44. $(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
  45. hostprogs-y += $(host-progs)
  46. endif
  47. endif
  48. # Do not include host rules unles needed
  49. ifneq ($(hostprogs-y)$(hostprogs-m),)
  50. include scripts/Makefile.host
  51. endif
  52. ifneq ($(KBUILD_SRC),)
  53. # Create output directory if not already present
  54. _dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
  55. # Create directories for object files if directory does not exist
  56. # Needed when obj-y := dir/file.o syntax is used
  57. _dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))
  58. endif
  59. ifndef obj
  60. $(warning kbuild: Makefile.build is included improperly)
  61. endif
  62. # ===========================================================================
  63. ifneq ($(strip $(lib-y) $(lib-m) $(lib-n) $(lib-)),)
  64. lib-target := $(obj)/lib.a
  65. endif
  66. ifneq ($(strip $(obj-y) $(obj-m) $(obj-n) $(obj-) $(lib-target)),)
  67. builtin-target := $(obj)/built-in.o
  68. endif
  69. modorder-target := $(obj)/modules.order
  70. # We keep a list of all modules in $(MODVERDIR)
  71. __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
  72. $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
  73. $(subdir-ym) $(always)
  74. @:
  75. # Linus' kernel sanity checking tool
  76. ifneq ($(KBUILD_CHECKSRC),0)
  77. ifeq ($(KBUILD_CHECKSRC),2)
  78. quiet_cmd_force_checksrc = CHECK $<
  79. cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
  80. else
  81. quiet_cmd_checksrc = CHECK $<
  82. cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
  83. endif
  84. endif
  85. # Compile C sources (.c)
  86. # ---------------------------------------------------------------------------
  87. # Default is built-in, unless we know otherwise
  88. modkern_cflags := $(CFLAGS_KERNEL)
  89. quiet_modtag := $(empty) $(empty)
  90. $(real-objs-m) : modkern_cflags := $(CFLAGS_MODULE)
  91. $(real-objs-m:.o=.i) : modkern_cflags := $(CFLAGS_MODULE)
  92. $(real-objs-m:.o=.s) : modkern_cflags := $(CFLAGS_MODULE)
  93. $(real-objs-m:.o=.lst): modkern_cflags := $(CFLAGS_MODULE)
  94. $(real-objs-m) : quiet_modtag := [M]
  95. $(real-objs-m:.o=.i) : quiet_modtag := [M]
  96. $(real-objs-m:.o=.s) : quiet_modtag := [M]
  97. $(real-objs-m:.o=.lst): quiet_modtag := [M]
  98. $(obj-m) : quiet_modtag := [M]
  99. # Default for not multi-part modules
  100. modname = $(basetarget)
  101. $(multi-objs-m) : modname = $(modname-multi)
  102. $(multi-objs-m:.o=.i) : modname = $(modname-multi)
  103. $(multi-objs-m:.o=.s) : modname = $(modname-multi)
  104. $(multi-objs-m:.o=.lst) : modname = $(modname-multi)
  105. $(multi-objs-y) : modname = $(modname-multi)
  106. $(multi-objs-y:.o=.i) : modname = $(modname-multi)
  107. $(multi-objs-y:.o=.s) : modname = $(modname-multi)
  108. $(multi-objs-y:.o=.lst) : modname = $(modname-multi)
  109. quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
  110. cmd_cc_s_c = $(CC) $(c_flags) -fverbose-asm -S -o $@ $<
  111. $(obj)/%.s: $(src)/%.c FORCE
  112. $(call if_changed_dep,cc_s_c)
  113. quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
  114. cmd_cc_i_c = $(CPP) $(c_flags) -o $@ $<
  115. $(obj)/%.i: $(src)/%.c FORCE
  116. $(call if_changed_dep,cc_i_c)
  117. quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
  118. cmd_cc_symtypes_c = \
  119. $(CPP) -D__GENKSYMS__ $(c_flags) $< \
  120. | $(GENKSYMS) -T $@ >/dev/null; \
  121. test -s $@ || rm -f $@
  122. $(obj)/%.symtypes : $(src)/%.c FORCE
  123. $(call if_changed_dep,cc_symtypes_c)
  124. # C (.c) files
  125. # The C file is compiled and updated dependency information is generated.
  126. # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
  127. quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
  128. ifndef CONFIG_MODVERSIONS
  129. cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
  130. else
  131. # When module versioning is enabled the following steps are executed:
  132. # o compile a .tmp_<file>.o from <file>.c
  133. # o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
  134. # not export symbols, we just rename .tmp_<file>.o to <file>.o and
  135. # are done.
  136. # o otherwise, we calculate symbol versions using the good old
  137. # genksyms on the preprocessed source and postprocess them in a way
  138. # that they are usable as a linker script
  139. # o generate <file>.o from .tmp_<file>.o using the linker to
  140. # replace the unresolved symbols __crc_exported_symbol with
  141. # the actual value of the checksum generated by genksyms
  142. cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
  143. cmd_modversions = \
  144. if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
  145. $(CPP) -D__GENKSYMS__ $(c_flags) $< \
  146. | $(GENKSYMS) $(if $(KBUILD_SYMTYPES), \
  147. -T $(@D)/$(@F:.o=.symtypes)) -a $(ARCH) \
  148. > $(@D)/.tmp_$(@F:.o=.ver); \
  149. \
  150. $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
  151. -T $(@D)/.tmp_$(@F:.o=.ver); \
  152. rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
  153. else \
  154. mv -f $(@D)/.tmp_$(@F) $@; \
  155. fi;
  156. endif
  157. define rule_cc_o_c
  158. $(call echo-cmd,checksrc) $(cmd_checksrc) \
  159. $(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \
  160. $(cmd_modversions) \
  161. scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \
  162. $(dot-target).tmp; \
  163. rm -f $(depfile); \
  164. mv -f $(dot-target).tmp $(dot-target).cmd
  165. endef
  166. # Built-in and composite module parts
  167. $(obj)/%.o: $(src)/%.c FORCE
  168. $(call cmd,force_checksrc)
  169. $(call if_changed_rule,cc_o_c)
  170. # Single-part modules are special since we need to mark them in $(MODVERDIR)
  171. $(single-used-m): $(obj)/%.o: $(src)/%.c FORCE
  172. $(call cmd,force_checksrc)
  173. $(call if_changed_rule,cc_o_c)
  174. @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
  175. quiet_cmd_cc_lst_c = MKLST $@
  176. cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
  177. $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
  178. System.map $(OBJDUMP) > $@
  179. $(obj)/%.lst: $(src)/%.c FORCE
  180. $(call if_changed_dep,cc_lst_c)
  181. # Compile assembler sources (.S)
  182. # ---------------------------------------------------------------------------
  183. modkern_aflags := $(AFLAGS_KERNEL)
  184. $(real-objs-m) : modkern_aflags := $(AFLAGS_MODULE)
  185. $(real-objs-m:.o=.s): modkern_aflags := $(AFLAGS_MODULE)
  186. quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
  187. cmd_as_s_S = $(CPP) $(a_flags) -o $@ $<
  188. $(obj)/%.s: $(src)/%.S FORCE
  189. $(call if_changed_dep,as_s_S)
  190. quiet_cmd_as_o_S = AS $(quiet_modtag) $@
  191. cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
  192. $(obj)/%.o: $(src)/%.S FORCE
  193. $(call if_changed_dep,as_o_S)
  194. targets += $(real-objs-y) $(real-objs-m) $(lib-y)
  195. targets += $(extra-y) $(MAKECMDGOALS) $(always)
  196. # Linker scripts preprocessor (.lds.S -> .lds)
  197. # ---------------------------------------------------------------------------
  198. quiet_cmd_cpp_lds_S = LDS $@
  199. cmd_cpp_lds_S = $(CPP) $(cpp_flags) -D__ASSEMBLY__ -o $@ $<
  200. $(obj)/%.lds: $(src)/%.lds.S FORCE
  201. $(call if_changed_dep,cpp_lds_S)
  202. # Build the compiled-in targets
  203. # ---------------------------------------------------------------------------
  204. # To build objects in subdirs, we need to descend into the directories
  205. $(sort $(subdir-obj-y)): $(subdir-ym) ;
  206. #
  207. # Rule to compile a set of .o files into one .o file
  208. #
  209. ifdef builtin-target
  210. quiet_cmd_link_o_target = LD $@
  211. # If the list of objects to link is empty, just create an empty built-in.o
  212. cmd_link_o_target = $(if $(strip $(obj-y)),\
  213. $(LD) $(ld_flags) -r -o $@ $(filter $(obj-y), $^),\
  214. rm -f $@; $(AR) rcs $@)
  215. $(builtin-target): $(obj-y) FORCE
  216. $(call if_changed,link_o_target)
  217. targets += $(builtin-target)
  218. endif # builtin-target
  219. #
  220. # Rule to create modules.order file
  221. #
  222. # Create commands to either record .ko file or cat modules.order from
  223. # a subdirectory
  224. modorder-cmds = \
  225. $(foreach m, $(modorder), \
  226. $(if $(filter %/modules.order, $m), \
  227. cat $m;, echo kernel/$m;))
  228. $(modorder-target): $(subdir-ym) FORCE
  229. $(Q)(cat /dev/null; $(modorder-cmds)) > $@
  230. #
  231. # Rule to compile a set of .o files into one .a file
  232. #
  233. ifdef lib-target
  234. quiet_cmd_link_l_target = AR $@
  235. cmd_link_l_target = rm -f $@; $(AR) rcs $@ $(lib-y)
  236. $(lib-target): $(lib-y) FORCE
  237. $(call if_changed,link_l_target)
  238. targets += $(lib-target)
  239. endif
  240. #
  241. # Rule to link composite objects
  242. #
  243. # Composite objects are specified in kbuild makefile as follows:
  244. # <composite-object>-objs := <list of .o files>
  245. # or
  246. # <composite-object>-y := <list of .o files>
  247. link_multi_deps = \
  248. $(filter $(addprefix $(obj)/, \
  249. $($(subst $(obj)/,,$(@:.o=-objs))) \
  250. $($(subst $(obj)/,,$(@:.o=-y)))), $^)
  251. quiet_cmd_link_multi-y = LD $@
  252. cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps)
  253. quiet_cmd_link_multi-m = LD [M] $@
  254. cmd_link_multi-m = $(cmd_link_multi-y)
  255. # We would rather have a list of rules like
  256. # foo.o: $(foo-objs)
  257. # but that's not so easy, so we rather make all composite objects depend
  258. # on the set of all their parts
  259. $(multi-used-y) : %.o: $(multi-objs-y) FORCE
  260. $(call if_changed,link_multi-y)
  261. $(multi-used-m) : %.o: $(multi-objs-m) FORCE
  262. $(call if_changed,link_multi-m)
  263. @{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod)
  264. targets += $(multi-used-y) $(multi-used-m)
  265. # Descending
  266. # ---------------------------------------------------------------------------
  267. PHONY += $(subdir-ym)
  268. $(subdir-ym):
  269. $(Q)$(MAKE) $(build)=$@
  270. # Add FORCE to the prequisites of a target to force it to be always rebuilt.
  271. # ---------------------------------------------------------------------------
  272. PHONY += FORCE
  273. FORCE:
  274. # Read all saved command lines and dependencies for the $(targets) we
  275. # may be building above, using $(if_changed{,_dep}). As an
  276. # optimization, we don't need to read them if the target does not
  277. # exist, we will rebuild anyway in that case.
  278. targets := $(wildcard $(sort $(targets)))
  279. cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
  280. ifneq ($(cmd_files),)
  281. include $(cmd_files)
  282. endif
  283. # Declare the contents of the .PHONY variable as phony. We keep that
  284. # information in a variable se we can use it in if_changed and friends.
  285. .PHONY: $(PHONY)