scripts/Makefile.build

   1 # ==========================================================================
   2 # Building
   3 # ==========================================================================
   4
   5 src := $(obj)
   6
   7 .PHONY: __build
   8 __build:
   9
  10 # Read .config if it exist, otherwise ignore
  11 -include .config
  12
  13 # The filename Kbuild has precedence over Makefile
  14 kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
  15 include $(if $(wildcard $(kbuild-dir)/Kbuild), $(kbuild-dir)/Kbuild, $(kbuild-dir)/Makefile)
  16
  17 include scripts/Kbuild.include
  18 include scripts/Makefile.lib
  19
  20 ifdef host-progs
  21 ifneq ($(hostprogs-y),$(host-progs))
  22 $(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
  23 hostprogs-y += $(host-progs)
  24 endif
  25 endif
  26
  27 # Do not include host rules unles needed
  28 ifneq ($(hostprogs-y)$(hostprogs-m),)
  29 include scripts/Makefile.host
  30 endif
  31
  32 ifneq ($(KBUILD_SRC),)
  33 # Create output directory if not already present
  34 _dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
  35
  36 # Create directories for object files if directory does not exist
  37 # Needed when obj-y := dir/file.o syntax is used
  38 _dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))
  39 endif
  40
  41
  42 ifdef EXTRA_TARGETS
  43 $(warning kbuild: $(obj)/Makefile - Usage of EXTRA_TARGETS is obsolete in 2.6. Please fix!)
  44 endif
  45
  46 ifdef build-targets
  47 $(warning kbuild: $(obj)/Makefile - Usage of build-targets is obsolete in 2.6. Please fix!)
  48 endif
  49
  50 ifdef export-objs
  51 $(warning kbuild: $(obj)/Makefile - Usage of export-objs is obsolete in 2.6. Please fix!)
  52 endif
  53
  54 ifdef O_TARGET
  55 $(warning kbuild: $(obj)/Makefile - Usage of O_TARGET := $(O_TARGET) is obsolete in 2.6. Please fix!)
  56 endif
  57
  58 ifdef L_TARGET
  59 $(error kbuild: $(obj)/Makefile - Use of L_TARGET is replaced by lib-y in 2.6. Please fix!)
  60 endif
  61
  62 ifdef list-multi
  63 $(warning kbuild: $(obj)/Makefile - list-multi := $(list-multi) is obsolete in 2.6. Please fix!)
  64 endif
  65
  66 ifndef obj
  67 $(warning kbuild: Makefile.build is included improperly)
  68 endif
  69
  70 # ===========================================================================
  71
  72 ifneq ($(strip $(lib-y) $(lib-m) $(lib-n) $(lib-)),)
  73 lib-target := $(obj)/lib.a
  74 endif
  75
  76 ifneq ($(strip $(obj-y) $(obj-m) $(obj-n) $(obj-) $(lib-target)),)
  77 builtin-target := $(obj)/built-in.o
  78 endif
  79
  80 # We keep a list of all modules in $(MODVERDIR)
  81
  82 __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
  83          $(if $(KBUILD_MODULES),$(obj-m)) \
  84          $(subdir-ym) $(always)
  85         @:
  86
  87 # Linus' kernel sanity checking tool
  88 ifneq ($(KBUILD_CHECKSRC),0)
  89   ifeq ($(KBUILD_CHECKSRC),2)
  90     quiet_cmd_force_checksrc = CHECK   $<
  91           cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
  92   else
  93       quiet_cmd_checksrc     = CHECK   $<
  94             cmd_checksrc     = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
  95   endif
  96 endif
  97
  98
  99 # Compile C sources (.c)
 100 # ---------------------------------------------------------------------------
 101
 102 # Default is built-in, unless we know otherwise
 103 modkern_cflags := $(CFLAGS_KERNEL)
 104 quiet_modtag := $(empty)   $(empty)
 105
 106 $(real-objs-m)        : modkern_cflags := $(CFLAGS_MODULE)
 107 $(real-objs-m:.o=.i)  : modkern_cflags := $(CFLAGS_MODULE)
 108 $(real-objs-m:.o=.s)  : modkern_cflags := $(CFLAGS_MODULE)
 109 $(real-objs-m:.o=.lst): modkern_cflags := $(CFLAGS_MODULE)
 110
 111 $(real-objs-m)        : quiet_modtag := [M]
 112 $(real-objs-m:.o=.i)  : quiet_modtag := [M]
 113 $(real-objs-m:.o=.s)  : quiet_modtag := [M]
 114 $(real-objs-m:.o=.lst): quiet_modtag := [M]
 115
 116 $(obj-m)              : quiet_modtag := [M]
 117
 118 # Default for not multi-part modules
 119 modname = $(*F)
 120
 121 $(multi-objs-m)         : modname = $(modname-multi)
 122 $(multi-objs-m:.o=.i)   : modname = $(modname-multi)
 123 $(multi-objs-m:.o=.s)   : modname = $(modname-multi)
 124 $(multi-objs-m:.o=.lst) : modname = $(modname-multi)
 125 $(multi-objs-y)         : modname = $(modname-multi)
 126 $(multi-objs-y:.o=.i)   : modname = $(modname-multi)
 127 $(multi-objs-y:.o=.s)   : modname = $(modname-multi)
 128 $(multi-objs-y:.o=.lst) : modname = $(modname-multi)
 129
 130 quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
 131 cmd_cc_s_c       = $(CC) $(c_flags) -S -o $@ $<
 132
 133 %.s: %.c FORCE
 134         $(call if_changed_dep,cc_s_c)
 135
 136 quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
 137 cmd_cc_i_c       = $(CPP) $(c_flags)   -o $@ $<
 138
 139 %.i: %.c FORCE
 140         $(call if_changed_dep,cc_i_c)
 141
 142 # C (.c) files
 143 # The C file is compiled and updated dependency information is generated.
 144 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
 145
 146 quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@
 147
 148 ifndef CONFIG_MODVERSIONS
 149 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
 150
 151 else
 152 # When module versioning is enabled the following steps are executed:
 153 # o compile a .tmp_<file>.o from <file>.c
 154 # o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
 155 #   not export symbols, we just rename .tmp_<file>.o to <file>.o and
 156 #   are done.
 157 # o otherwise, we calculate symbol versions using the good old
 158 #   genksyms on the preprocessed source and postprocess them in a way
 159 #   that they are usable as a linker script
 160 # o generate <file>.o from .tmp_<file>.o using the linker to
 161 #   replace the unresolved symbols __crc_exported_symbol with
 162 #   the actual value of the checksum generated by genksyms
 163
 164 cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
 165 cmd_modversions =                                                       \
 166         if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then     \
 167                 $(CPP) -D__GENKSYMS__ $(c_flags) $<                     \
 168                 | $(GENKSYMS)                                           \
 169                 > $(@D)/.tmp_$(@F:.o=.ver);                             \
 170                                                                         \
 171                 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F)              \
 172                         -T $(@D)/.tmp_$(@F:.o=.ver);                    \
 173                 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver);        \
 174         else                                                            \
 175                 mv -f $(@D)/.tmp_$(@F) $@;                              \
 176         fi;
 177 endif
 178
 179 define rule_cc_o_c
 180         $(if $($(quiet)cmd_checksrc),echo '  $($(quiet)cmd_checksrc)';)   \
 181         $(cmd_checksrc)                                                   \
 182         $(if $($(quiet)cmd_cc_o_c),echo '  $(call escsq,$($(quiet)cmd_cc_o_c))';)  \
 183         $(cmd_cc_o_c);                                                    \
 184         $(cmd_modversions)                                                \
 185         scripts/basic/fixdep $(depfile) $@ '$(call escsq,$(cmd_cc_o_c))' > $(@D)/.$(@F).tmp;  \
 186         rm -f $(depfile);                                                 \
 187         mv -f $(@D)/.$(@F).tmp $(@D)/.$(@F).cmd
 188 endef
 189
 190 # Built-in and composite module parts
 191
 192 %.o: %.c FORCE
 193         $(call cmd,force_checksrc)
 194         $(call if_changed_rule,cc_o_c)
 195
 196 # Single-part modules are special since we need to mark them in $(MODVERDIR)
 197
 198 $(single-used-m): %.o: %.c FORCE
 199         $(call cmd,force_checksrc)
 200         $(call if_changed_rule,cc_o_c)
 201         @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
 202
 203 quiet_cmd_cc_lst_c = MKLST   $@
 204       cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
 205                      $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
 206                                      System.map $(OBJDUMP) > $@
 207
 208 %.lst: %.c FORCE
 209         $(call if_changed_dep,cc_lst_c)
 210
 211 # Compile assembler sources (.S)
 212 # ---------------------------------------------------------------------------
 213
 214 modkern_aflags := $(AFLAGS_KERNEL)
 215
 216 $(real-objs-m)      : modkern_aflags := $(AFLAGS_MODULE)
 217 $(real-objs-m:.o=.s): modkern_aflags := $(AFLAGS_MODULE)
 218
 219 quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
 220 cmd_as_s_S       = $(CPP) $(a_flags)   -o $@ $<
 221
 222 %.s: %.S FORCE
 223         $(call if_changed_dep,as_s_S)
 224
 225 quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
 226 cmd_as_o_S       = $(CC) $(a_flags) -c -o $@ $<
 227
 228 %.o: %.S FORCE
 229         $(call if_changed_dep,as_o_S)
 230
 231 targets += $(real-objs-y) $(real-objs-m) $(lib-y)
 232 targets += $(extra-y) $(MAKECMDGOALS) $(always)
 233
 234 # Linker scripts preprocessor (.lds.S -> .lds)
 235 # ---------------------------------------------------------------------------
 236 quiet_cmd_cpp_lds_S = LDS     $@
 237       cmd_cpp_lds_S = $(CPP) $(cpp_flags) -D__ASSEMBLY__ -o $@ $<
 238
 239 %.lds: %.lds.S FORCE
 240         $(call if_changed_dep,cpp_lds_S)
 241
 242 # Build the compiled-in targets
 243 # ---------------------------------------------------------------------------
 244
 245 # To build objects in subdirs, we need to descend into the directories
 246 $(sort $(subdir-obj-y)): $(subdir-ym) ;
 247
 248 #
 249 # Rule to compile a set of .o files into one .o file
 250 #
 251 ifdef builtin-target
 252 quiet_cmd_link_o_target = LD      $@
 253 # If the list of objects to link is empty, just create an empty built-in.o
 254 cmd_link_o_target = $(if $(strip $(obj-y)),\
 255                       $(LD) $(ld_flags) -r -o $@ $(filter $(obj-y), $^),\
 256                       rm -f $@; $(AR) rcs $@)
 257
 258 $(builtin-target): $(obj-y) FORCE
 259         $(call if_changed,link_o_target)
 260
 261 targets += $(builtin-target)
 262 endif # builtin-target
 263
 264 #
 265 # Rule to compile a set of .o files into one .a file
 266 #
 267 ifdef lib-target
 268 quiet_cmd_link_l_target = AR      $@
 269 cmd_link_l_target = rm -f $@; $(AR) $(EXTRA_ARFLAGS) rcs $@ $(lib-y)
 270
 271 $(lib-target): $(lib-y) FORCE
 272         $(call if_changed,link_l_target)
 273
 274 targets += $(lib-target)
 275 endif
 276
 277 #
 278 # Rule to link composite objects
 279 #
 280 #  Composite objects are specified in kbuild makefile as follows:
 281 #    <composite-object>-objs := <list of .o files>
 282 #  or
 283 #    <composite-object>-y    := <list of .o files>
 284 link_multi_deps =                     \
 285 $(filter $(addprefix $(obj)/,         \
 286 $($(subst $(obj)/,,$(@:.o=-objs)))    \
 287 $($(subst $(obj)/,,$(@:.o=-y)))), $^)
 288
 289 quiet_cmd_link_multi-y = LD      $@
 290 cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps)
 291
 292 quiet_cmd_link_multi-m = LD [M]  $@
 293 cmd_link_multi-m = $(LD) $(ld_flags) $(LDFLAGS_MODULE) -o $@ $(link_multi_deps)
 294
 295 # We would rather have a list of rules like
 296 #       foo.o: $(foo-objs)
 297 # but that's not so easy, so we rather make all composite objects depend
 298 # on the set of all their parts
 299 $(multi-used-y) : %.o: $(multi-objs-y) FORCE
 300         $(call if_changed,link_multi-y)
 301
 302 $(multi-used-m) : %.o: $(multi-objs-m) FORCE
 303         $(call if_changed,link_multi-m)
 304         @{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod)
 305
 306 targets += $(multi-used-y) $(multi-used-m)
 307
 308
 309 # Descending
 310 # ---------------------------------------------------------------------------
 311
 312 .PHONY: $(subdir-ym)
 313 $(subdir-ym):
 314         $(Q)$(MAKE) $(build)=$@
 315
 316 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
 317 # ---------------------------------------------------------------------------
 318
 319 .PHONY: FORCE
 320
 321 FORCE:
 322
 323 # Read all saved command lines and dependencies for the $(targets) we
 324 # may be building above, using $(if_changed{,_dep}). As an
 325 # optimization, we don't need to read them if the target does not
 326 # exist, we will rebuild anyway in that case.
 327
 328 targets := $(wildcard $(sort $(targets)))
 329 cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
 330
 331 ifneq ($(cmd_files),)
 332   include $(cmd_files)
 333 endif