scripts/Makefile.build

   1 # ==========================================================================
   2 # Building
   3 # ==========================================================================
   4
   5 src := $(obj)
   6
   7 PHONY := __build
   8 __build:
   9
  10 # Init all relevant variables used in kbuild files so
  11 # 1) they have correct type
  12 # 2) they do not inherit any value from the environment
  13 obj-y :=
  14 obj-m :=
  15 lib-y :=
  16 lib-m :=
  17 always :=
  18 targets :=
  19 subdir-y :=
  20 subdir-m :=
  21 EXTRA_AFLAGS   :=
  22 EXTRA_CFLAGS   :=
  23 EXTRA_CPPFLAGS :=
  24 EXTRA_LDFLAGS  :=
  25 asflags-y  :=
  26 ccflags-y  :=
  27 cppflags-y :=
  28 ldflags-y  :=
  29
  30 # Read auto.conf if it exists, otherwise ignore
  31 -include include/config/auto.conf
  32
  33 include scripts/Kbuild.include
  34
  35 # For backward compatibility check that these variables do not change
  36 save-cflags := $(CFLAGS)
  37
  38 # The filename Kbuild has precedence over Makefile
  39 kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
  40 kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
  41 include $(kbuild-file)
  42
  43 # If the save-* variables changed error out
  44 ifeq ($(KBUILD_NOPEDANTIC),)
  45         ifneq ("$(save-cflags)","$(CFLAGS)")
  46                 $(error CFLAGS was changed in "$(kbuild-file)". Fix it to use EXTRA_CFLAGS)
  47         endif
  48 endif
  49 include scripts/Makefile.lib
  50
  51 ifdef host-progs
  52 ifneq ($(hostprogs-y),$(host-progs))
  53 $(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
  54 hostprogs-y += $(host-progs)
  55 endif
  56 endif
  57
  58 # Do not include host rules unless needed
  59 ifneq ($(hostprogs-y)$(hostprogs-m),)
  60 include scripts/Makefile.host
  61 endif
  62
  63 ifneq ($(KBUILD_SRC),)
  64 # Create output directory if not already present
  65 _dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
  66
  67 # Create directories for object files if directory does not exist
  68 # Needed when obj-y := dir/file.o syntax is used
  69 _dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))
  70 endif
  71
  72 ifndef obj
  73 $(warning kbuild: Makefile.build is included improperly)
  74 endif
  75
  76 # ===========================================================================
  77
  78 ifneq ($(strip $(lib-y) $(lib-m) $(lib-n) $(lib-)),)
  79 lib-target := $(obj)/lib.a
  80 endif
  81
  82 ifneq ($(strip $(obj-y) $(obj-m) $(obj-n) $(obj-) $(lib-target)),)
  83 builtin-target := $(obj)/built-in.o
  84 endif
  85
  86 modorder-target := $(obj)/modules.order
  87
  88 # We keep a list of all modules in $(MODVERDIR)
  89
  90 __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
  91          $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
  92          $(subdir-ym) $(always)
  93         @:
  94
  95 # Linus' kernel sanity checking tool
  96 ifneq ($(KBUILD_CHECKSRC),0)
  97   ifeq ($(KBUILD_CHECKSRC),2)
  98     quiet_cmd_force_checksrc = CHECK   $<
  99           cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
 100   else
 101       quiet_cmd_checksrc     = CHECK   $<
 102             cmd_checksrc     = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
 103   endif
 104 endif
 105
 106 # Do section mismatch analysis for each module/built-in.o
 107 ifdef CONFIG_DEBUG_SECTION_MISMATCH
 108   cmd_secanalysis = ; scripts/mod/modpost $@
 109 endif
 110
 111 # Compile C sources (.c)
 112 # ---------------------------------------------------------------------------
 113
 114 # Default is built-in, unless we know otherwise
 115 modkern_cflags := $(CFLAGS_KERNEL)
 116 quiet_modtag := $(empty)   $(empty)
 117
 118 $(real-objs-m)        : modkern_cflags := $(CFLAGS_MODULE)
 119 $(real-objs-m:.o=.i)  : modkern_cflags := $(CFLAGS_MODULE)
 120 $(real-objs-m:.o=.s)  : modkern_cflags := $(CFLAGS_MODULE)
 121 $(real-objs-m:.o=.lst): modkern_cflags := $(CFLAGS_MODULE)
 122
 123 $(real-objs-m)        : quiet_modtag := [M]
 124 $(real-objs-m:.o=.i)  : quiet_modtag := [M]
 125 $(real-objs-m:.o=.s)  : quiet_modtag := [M]
 126 $(real-objs-m:.o=.lst): quiet_modtag := [M]
 127
 128 $(obj-m)              : quiet_modtag := [M]
 129
 130 # Default for not multi-part modules
 131 modname = $(basetarget)
 132
 133 $(multi-objs-m)         : modname = $(modname-multi)
 134 $(multi-objs-m:.o=.i)   : modname = $(modname-multi)
 135 $(multi-objs-m:.o=.s)   : modname = $(modname-multi)
 136 $(multi-objs-m:.o=.lst) : modname = $(modname-multi)
 137 $(multi-objs-y)         : modname = $(modname-multi)
 138 $(multi-objs-y:.o=.i)   : modname = $(modname-multi)
 139 $(multi-objs-y:.o=.s)   : modname = $(modname-multi)
 140 $(multi-objs-y:.o=.lst) : modname = $(modname-multi)
 141
 142 quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
 143 cmd_cc_s_c       = $(CC) $(c_flags) -fverbose-asm -S -o $@ $<
 144
 145 $(obj)/%.s: $(src)/%.c FORCE
 146         $(call if_changed_dep,cc_s_c)
 147
 148 quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
 149 cmd_cc_i_c       = $(CPP) $(c_flags)   -o $@ $<
 150
 151 $(obj)/%.i: $(src)/%.c FORCE
 152         $(call if_changed_dep,cc_i_c)
 153
 154 cmd_genksyms =                                                              \
 155     $(CPP) -D__GENKSYMS__ $(c_flags) $< |                                   \
 156     $(GENKSYMS) -T $@ -A -a $(ARCH)                                         \
 157      $(if $(KBUILD_PRESERVE),-p)                                            \
 158      $(if $(1),-r $(firstword $(wildcard $(@:.symtypes=.symref) /dev/null)))
 159
 160 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
 161 cmd_cc_symtypes_c =                                                         \
 162     set -e;                                                                 \
 163     $(call cmd_genksyms, true) >/dev/null;                                  \
 164     test -s $@ || rm -f $@
 165
 166 $(obj)/%.symtypes : $(src)/%.c FORCE
 167         $(call cmd,cc_symtypes_c)
 168
 169 # C (.c) files
 170 # The C file is compiled and updated dependency information is generated.
 171 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
 172
 173 quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@
 174
 175 ifndef CONFIG_MODVERSIONS
 176 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
 177
 178 else
 179 # When module versioning is enabled the following steps are executed:
 180 # o compile a .tmp_<file>.s from <file>.c
 181 # o if .tmp_<file>.s doesn't contain a __ksymtab version, i.e. does
 182 #   not export symbols, we just assemble .tmp_<file>.s to <file>.o and
 183 #   are done.
 184 # o otherwise, we calculate symbol versions using the good old
 185 #   genksyms on the preprocessed source and postprocess them in a way
 186 #   that they are usable as assembly source
 187 # o assemble <file>.o from .tmp_<file>.s forcing inclusion of directives
 188 #   defining the actual values of __crc_*, followed by objcopy-ing them
 189 #   to force these symbols to be local to permit stripping them later.
 190 s_file = $(@D)/.tmp_$(@F:.o=.s)
 191 v_file = $(@D)/.tmp_$(@F:.o=.v)
 192 tmp_o_file = $(@D)/.tmp_$(@F)
 193 no_g_c_flags = $(filter-out -g%,$(c_flags))
 194
 195 cmd_cc_o_c = $(CC) $(c_flags) -S -o $(s_file) $<
 196
 197 cmd_modversions =                                                       \
 198         if grep -q __ksymtab $(s_file); then                            \
 199                 if $(call cmd_genksyms, $(KBUILD_SYMTYPES)) > $(v_file) \
 200                    && $(CC) $(no_g_c_flags) -c -Wa,$(v_file)            \
 201                             -o $(tmp_o_file) $(s_file)                  \
 202                    && $(OBJCOPY) -L '__crc_*' -L '___crc_*' -w          \
 203                                  $(tmp_o_file) $@;                      \
 204                 then                                                    \
 205                         : ;                                             \
 206                 else                                                    \
 207                         rm -f $@; exit 1;                               \
 208                 fi;                                                     \
 209         else                                                            \
 210                 rm -f $(v_file);                                        \
 211                 $(CC) $(no_g_c_flags) -c -o $@ $(s_file);               \
 212         fi;
 213 endif
 214
 215 ifdef CONFIG_64BIT
 216 arch_bits = 64
 217 else
 218 arch_bits = 32
 219 endif
 220
 221 ifdef CONFIG_FTRACE_MCOUNT_RECORD
 222 cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl \
 223         "$(ARCH)" "$(arch_bits)" "$(OBJDUMP)" "$(OBJCOPY)" "$(CC)" "$(LD)" \
 224         "$(NM)" "$(RM)" "$(MV)" "$(@)";
 225 endif
 226
 227 define rule_cc_o_c
 228         $(call echo-cmd,checksrc) $(cmd_checksrc)                         \
 229         $(call echo-cmd,cc_o_c) $(cmd_cc_o_c);                            \
 230         $(cmd_modversions)                                                \
 231         $(cmd_record_mcount)                                              \
 232         scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' >    \
 233                                                       $(dot-target).tmp;  \
 234         if [ -r $(@D)/.tmp_$(@F:.o=.v) ]; then                            \
 235                 echo >> $(dot-target).tmp;                                \
 236                 echo '$@: $(GENKSYMS)' >> $(dot-target).tmp;              \
 237                 echo '$(GENKSYMS):: ;' >> $(dot-target).tmp;              \
 238         fi;                                                               \
 239         rm -f $(depfile) $(@D)/.tmp_$(@F:.o=.?);                          \
 240         mv -f $(dot-target).tmp $(dot-target).cmd
 241 endef
 242
 243 # Built-in and composite module parts
 244 $(obj)/%.o: $(src)/%.c FORCE
 245         $(call cmd,force_checksrc)
 246         $(call if_changed_rule,cc_o_c)
 247
 248 # Single-part modules are special since we need to mark them in $(MODVERDIR)
 249
 250 $(single-used-m): $(obj)/%.o: $(src)/%.c FORCE
 251         $(call cmd,force_checksrc)
 252         $(call if_changed_rule,cc_o_c)
 253         @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
 254
 255 quiet_cmd_cc_lst_c = MKLST   $@
 256       cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
 257                      $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
 258                                      System.map $(OBJDUMP) > $@
 259
 260 $(obj)/%.lst: $(src)/%.c FORCE
 261         $(call if_changed_dep,cc_lst_c)
 262
 263 # Compile assembler sources (.S)
 264 # ---------------------------------------------------------------------------
 265
 266 modkern_aflags := $(AFLAGS_KERNEL)
 267
 268 $(real-objs-m)      : modkern_aflags := $(AFLAGS_MODULE)
 269 $(real-objs-m:.o=.s): modkern_aflags := $(AFLAGS_MODULE)
 270
 271 quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
 272 cmd_as_s_S       = $(CPP) $(a_flags)   -o $@ $<
 273
 274 $(obj)/%.s: $(src)/%.S FORCE
 275         $(call if_changed_dep,as_s_S)
 276
 277 quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
 278 cmd_as_o_S       = $(CC) $(a_flags) -c -o $@ $<
 279
 280 $(obj)/%.o: $(src)/%.S FORCE
 281         $(call if_changed_dep,as_o_S)
 282
 283 targets += $(real-objs-y) $(real-objs-m) $(lib-y)
 284 targets += $(extra-y) $(MAKECMDGOALS) $(always)
 285
 286 # Linker scripts preprocessor (.lds.S -> .lds)
 287 # ---------------------------------------------------------------------------
 288 quiet_cmd_cpp_lds_S = LDS     $@
 289       cmd_cpp_lds_S = $(CPP) $(cpp_flags) -D__ASSEMBLY__ -o $@ $<
 290
 291 $(obj)/%.lds: $(src)/%.lds.S FORCE
 292         $(call if_changed_dep,cpp_lds_S)
 293
 294 # Build the compiled-in targets
 295 # ---------------------------------------------------------------------------
 296
 297 # To build objects in subdirs, we need to descend into the directories
 298 $(sort $(subdir-obj-y)): $(subdir-ym) ;
 299
 300 #
 301 # Rule to compile a set of .o files into one .o file
 302 #
 303 ifdef builtin-target
 304 quiet_cmd_link_o_target = LD      $@
 305 # If the list of objects to link is empty, just create an empty built-in.o
 306 cmd_link_o_target = $(if $(strip $(obj-y)),\
 307                       $(LD) $(ld_flags) -r -o $@ $(filter $(obj-y), $^) \
 308                       $(cmd_secanalysis),\
 309                       rm -f $@; $(AR) rcs $@)
 310
 311 $(builtin-target): $(obj-y) FORCE
 312         $(call if_changed,link_o_target)
 313
 314 targets += $(builtin-target)
 315 endif # builtin-target
 316
 317 #
 318 # Rule to create modules.order file
 319 #
 320 # Create commands to either record .ko file or cat modules.order from
 321 # a subdirectory
 322 modorder-cmds =                                         \
 323         $(foreach m, $(modorder),                       \
 324                 $(if $(filter %/modules.order, $m),     \
 325                         cat $m;, echo kernel/$m;))
 326
 327 $(modorder-target): $(subdir-ym) FORCE
 328         $(Q)(cat /dev/null; $(modorder-cmds)) > $@
 329
 330 #
 331 # Rule to compile a set of .o files into one .a file
 332 #
 333 ifdef lib-target
 334 quiet_cmd_link_l_target = AR      $@
 335 cmd_link_l_target = rm -f $@; $(AR) rcs $@ $(lib-y)
 336
 337 $(lib-target): $(lib-y) FORCE
 338         $(call if_changed,link_l_target)
 339
 340 targets += $(lib-target)
 341 endif
 342
 343 #
 344 # Rule to link composite objects
 345 #
 346 #  Composite objects are specified in kbuild makefile as follows:
 347 #    <composite-object>-objs := <list of .o files>
 348 #  or
 349 #    <composite-object>-y    := <list of .o files>
 350 link_multi_deps =                     \
 351 $(filter $(addprefix $(obj)/,         \
 352 $($(subst $(obj)/,,$(@:.o=-objs)))    \
 353 $($(subst $(obj)/,,$(@:.o=-y)))), $^)
 354
 355 quiet_cmd_link_multi-y = LD      $@
 356 cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
 357
 358 quiet_cmd_link_multi-m = LD [M]  $@
 359 cmd_link_multi-m = $(cmd_link_multi-y)
 360
 361 # We would rather have a list of rules like
 362 #       foo.o: $(foo-objs)
 363 # but that's not so easy, so we rather make all composite objects depend
 364 # on the set of all their parts
 365 $(multi-used-y) : %.o: $(multi-objs-y) FORCE
 366         $(call if_changed,link_multi-y)
 367
 368 $(multi-used-m) : %.o: $(multi-objs-m) FORCE
 369         $(call if_changed,link_multi-m)
 370         @{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod)
 371
 372 targets += $(multi-used-y) $(multi-used-m)
 373
 374
 375 # Descending
 376 # ---------------------------------------------------------------------------
 377
 378 PHONY += $(subdir-ym)
 379 $(subdir-ym):
 380         $(Q)$(MAKE) $(build)=$@
 381
 382 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
 383 # ---------------------------------------------------------------------------
 384
 385 PHONY += FORCE
 386
 387 FORCE:
 388
 389 # Read all saved command lines and dependencies for the $(targets) we
 390 # may be building above, using $(if_changed{,_dep}). As an
 391 # optimization, we don't need to read them if the target does not
 392 # exist, we will rebuild anyway in that case.
 393
 394 targets := $(wildcard $(sort $(targets)))
 395 cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
 396
 397 ifneq ($(cmd_files),)
 398   include $(cmd_files)
 399 endif
 400
 401
 402 # Declare the contents of the .PHONY variable as phony.  We keep that
 403 # information in a variable se we can use it in if_changed and friends.
 404
 405 .PHONY: $(PHONY)