1# ========================================================================== 2# Building 3# ========================================================================== 4 5src := $(obj) 6 7PHONY := __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 13obj-y := 14obj-m := 15lib-y := 16lib-m := 17always := 18targets := 19subdir-y := 20subdir-m := 21EXTRA_AFLAGS := 22EXTRA_CFLAGS := 23EXTRA_CPPFLAGS := 24EXTRA_LDFLAGS := 25asflags-y := 26ccflags-y := 27cppflags-y := 28ldflags-y := 29 30subdir-asflags-y := 31subdir-ccflags-y := 32 33# Read auto.conf if it exists, otherwise ignore 34-include include/config/auto.conf 35 36include scripts/Kbuild.include 37 38# For backward compatibility check that these variables do not change 39save-cflags := $(CFLAGS) 40 41# The filename Kbuild has precedence over Makefile 42kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src)) 43kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile) 44include $(kbuild-file) 45 46# If the save-* variables changed error out 47ifeq ($(KBUILD_NOPEDANTIC),) 48 ifneq ("$(save-cflags)","$(CFLAGS)") 49 $(error CFLAGS was changed in "$(kbuild-file)". Fix it to use ccflags-y) 50 endif 51endif 52 53include scripts/Makefile.lib 54 55ifdef host-progs 56ifneq ($(hostprogs-y),$(host-progs)) 57$(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!) 58hostprogs-y += $(host-progs) 59endif 60endif 61 62# Do not include host rules unless needed 63ifneq ($(hostprogs-y)$(hostprogs-m),) 64include scripts/Makefile.host 65endif 66 67ifneq ($(KBUILD_SRC),) 68# Create output directory if not already present 69_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj)) 70 71# Create directories for object files if directory does not exist 72# Needed when obj-y := dir/file.o syntax is used 73_dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d))) 74endif 75 76ifndef obj 77$(warning kbuild: Makefile.build is included improperly) 78endif 79 80# =========================================================================== 81 82ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),) 83lib-target := $(obj)/lib.a 84endif 85 86ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib-target)),) 87builtin-target := $(obj)/built-in.o 88endif 89 90modorder-target := $(obj)/modules.order 91 92# We keep a list of all modules in $(MODVERDIR) 93 94__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \ 95 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \ 96 $(subdir-ym) $(always) 97 @: 98 99# Linus' kernel sanity checking tool 100ifneq ($(KBUILD_CHECKSRC),0) 101 ifeq ($(KBUILD_CHECKSRC),2) 102 quiet_cmd_force_checksrc = CHECK $< 103 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ; 104 else 105 quiet_cmd_checksrc = CHECK $< 106 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ; 107 endif 108endif 109 110# Do section mismatch analysis for each module/built-in.o 111ifdef CONFIG_DEBUG_SECTION_MISMATCH 112 cmd_secanalysis = ; scripts/mod/modpost $@ 113endif 114 115# Compile C sources (.c) 116# --------------------------------------------------------------------------- 117 118# Default is built-in, unless we know otherwise 119modkern_cflags = \ 120 $(if $(part-of-module), \ 121 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \ 122 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL)) 123quiet_modtag := $(empty) $(empty) 124 125$(real-objs-m) : part-of-module := y 126$(real-objs-m:.o=.i) : part-of-module := y 127$(real-objs-m:.o=.s) : part-of-module := y 128$(real-objs-m:.o=.lst): part-of-module := y 129 130$(real-objs-m) : quiet_modtag := [M] 131$(real-objs-m:.o=.i) : quiet_modtag := [M] 132$(real-objs-m:.o=.s) : quiet_modtag := [M] 133$(real-objs-m:.o=.lst): quiet_modtag := [M] 134 135$(obj-m) : quiet_modtag := [M] 136 137# Default for not multi-part modules 138modname = $(basetarget) 139 140$(multi-objs-m) : modname = $(modname-multi) 141$(multi-objs-m:.o=.i) : modname = $(modname-multi) 142$(multi-objs-m:.o=.s) : modname = $(modname-multi) 143$(multi-objs-m:.o=.lst) : modname = $(modname-multi) 144$(multi-objs-y) : modname = $(modname-multi) 145$(multi-objs-y:.o=.i) : modname = $(modname-multi) 146$(multi-objs-y:.o=.s) : modname = $(modname-multi) 147$(multi-objs-y:.o=.lst) : modname = $(modname-multi) 148 149quiet_cmd_cc_s_c = CC $(quiet_modtag) $@ 150cmd_cc_s_c = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $< 151 152$(obj)/%.s: $(src)/%.c FORCE 153 $(call if_changed_dep,cc_s_c) 154 155quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@ 156cmd_cc_i_c = $(CPP) $(c_flags) -o $@ $< 157 158$(obj)/%.i: $(src)/%.c FORCE 159 $(call if_changed_dep,cc_i_c) 160 161cmd_gensymtypes = \ 162 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \ 163 $(GENKSYMS) $(if $(1), -T $(2)) \ 164 $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \ 165 $(if $(KBUILD_PRESERVE),-p) \ 166 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null)) 167 168quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@ 169cmd_cc_symtypes_c = \ 170 set -e; \ 171 $(call cmd_gensymtypes,true,$@) >/dev/null; \ 172 test -s $@ || rm -f $@ 173 174$(obj)/%.symtypes : $(src)/%.c FORCE 175 $(call cmd,cc_symtypes_c) 176 177# C (.c) files 178# The C file is compiled and updated dependency information is generated. 179# (See cmd_cc_o_c + relevant part of rule_cc_o_c) 180 181quiet_cmd_cc_o_c = CC $(quiet_modtag) $@ 182 183ifndef CONFIG_MODVERSIONS 184cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< 185 186else 187# When module versioning is enabled the following steps are executed: 188# o compile a .tmp_<file>.o from <file>.c 189# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does 190# not export symbols, we just rename .tmp_<file>.o to <file>.o and 191# are done. 192# o otherwise, we calculate symbol versions using the good old 193# genksyms on the preprocessed source and postprocess them in a way 194# that they are usable as a linker script 195# o generate <file>.o from .tmp_<file>.o using the linker to 196# replace the unresolved symbols __crc_exported_symbol with 197# the actual value of the checksum generated by genksyms 198 199cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $< 200cmd_modversions = \ 201 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \ 202 $(call cmd_gensymtypes,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ 203 > $(@D)/.tmp_$(@F:.o=.ver); \ 204 \ 205 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \ 206 -T $(@D)/.tmp_$(@F:.o=.ver); \ 207 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \ 208 else \ 209 mv -f $(@D)/.tmp_$(@F) $@; \ 210 fi; 211endif 212 213ifdef CONFIG_FTRACE_MCOUNT_RECORD 214ifdef BUILD_C_RECORDMCOUNT 215ifeq ("$(origin RECORDMCOUNT_WARN)", "command line") 216 RECORDMCOUNT_FLAGS = -w 217endif 218# Due to recursion, we must skip empty.o. 219# The empty.o file is created in the make process in order to determine 220# the target endianness and word size. It is made before all other C 221# files, including recordmcount. 222sub_cmd_record_mcount = \ 223 if [ $(@) != "scripts/mod/empty.o" ]; then \ 224 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \ 225 fi; 226recordmcount_source := $(srctree)/scripts/recordmcount.c \ 227 $(srctree)/scripts/recordmcount.h 228else 229sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \ 230 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \ 231 "$(if $(CONFIG_64BIT),64,32)" \ 232 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \ 233 "$(LD)" "$(NM)" "$(RM)" "$(MV)" \ 234 "$(if $(part-of-module),1,0)" "$(@)"; 235recordmcount_source := $(srctree)/scripts/recordmcount.pl 236endif 237cmd_record_mcount = \ 238 if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \ 239 "$(CC_FLAGS_FTRACE)" ]; then \ 240 $(sub_cmd_record_mcount) \ 241 fi; 242endif 243 244define rule_cc_o_c 245 $(call echo-cmd,checksrc) $(cmd_checksrc) \ 246 $(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \ 247 $(cmd_modversions) \ 248 $(call echo-cmd,record_mcount) \ 249 $(cmd_record_mcount) \ 250 scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \ 251 $(dot-target).tmp; \ 252 rm -f $(depfile); \ 253 mv -f $(dot-target).tmp $(dot-target).cmd 254endef 255 256# Built-in and composite module parts 257$(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE 258 $(call cmd,force_checksrc) 259 $(call if_changed_rule,cc_o_c) 260 261# Single-part modules are special since we need to mark them in $(MODVERDIR) 262 263$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE 264 $(call cmd,force_checksrc) 265 $(call if_changed_rule,cc_o_c) 266 @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod) 267 268quiet_cmd_cc_lst_c = MKLST $@ 269 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \ 270 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \ 271 System.map $(OBJDUMP) > $@ 272 273$(obj)/%.lst: $(src)/%.c FORCE 274 $(call if_changed_dep,cc_lst_c) 275 276# Compile assembler sources (.S) 277# --------------------------------------------------------------------------- 278 279modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL) 280 281$(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE) 282$(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE) 283 284quiet_cmd_as_s_S = CPP $(quiet_modtag) $@ 285cmd_as_s_S = $(CPP) $(a_flags) -o $@ $< 286 287$(obj)/%.s: $(src)/%.S FORCE 288 $(call if_changed_dep,as_s_S) 289 290quiet_cmd_as_o_S = AS $(quiet_modtag) $@ 291cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< 292 293$(obj)/%.o: $(src)/%.S FORCE 294 $(call if_changed_dep,as_o_S) 295 296targets += $(real-objs-y) $(real-objs-m) $(lib-y) 297targets += $(extra-y) $(MAKECMDGOALS) $(always) 298 299# Linker scripts preprocessor (.lds.S -> .lds) 300# --------------------------------------------------------------------------- 301quiet_cmd_cpp_lds_S = LDS $@ 302 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \ 303 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $< 304 305$(obj)/%.lds: $(src)/%.lds.S FORCE 306 $(call if_changed_dep,cpp_lds_S) 307 308# ASN.1 grammar 309# --------------------------------------------------------------------------- 310quiet_cmd_asn1_compiler = ASN.1 $@ 311 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \ 312 $(subst .h,.c,$@) $(subst .c,.h,$@) 313 314.PRECIOUS: $(objtree)/$(obj)/%-asn1.c $(objtree)/$(obj)/%-asn1.h 315 316$(obj)/%-asn1.c $(obj)/%-asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler 317 $(call cmd,asn1_compiler) 318 319# Build the compiled-in targets 320# --------------------------------------------------------------------------- 321 322# To build objects in subdirs, we need to descend into the directories 323$(sort $(subdir-obj-y)): $(subdir-ym) ; 324 325# 326# Rule to compile a set of .o files into one .o file 327# 328ifdef builtin-target 329quiet_cmd_link_o_target = LD $@ 330# If the list of objects to link is empty, just create an empty built-in.o 331cmd_link_o_target = $(if $(strip $(obj-y)),\ 332 $(LD) $(ld_flags) -r -o $@ $(filter $(obj-y), $^) \ 333 $(cmd_secanalysis),\ 334 rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@) 335 336$(builtin-target): $(obj-y) FORCE 337 $(call if_changed,link_o_target) 338 339targets += $(builtin-target) 340endif # builtin-target 341 342# 343# Rule to create modules.order file 344# 345# Create commands to either record .ko file or cat modules.order from 346# a subdirectory 347modorder-cmds = \ 348 $(foreach m, $(modorder), \ 349 $(if $(filter %/modules.order, $m), \ 350 cat $m;, echo kernel/$m;)) 351 352$(modorder-target): $(subdir-ym) FORCE 353 $(Q)(cat /dev/null; $(modorder-cmds)) > $@ 354 355# 356# Rule to compile a set of .o files into one .a file 357# 358ifdef lib-target 359quiet_cmd_link_l_target = AR $@ 360cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y) 361 362$(lib-target): $(lib-y) FORCE 363 $(call if_changed,link_l_target) 364 365targets += $(lib-target) 366endif 367 368# 369# Rule to link composite objects 370# 371# Composite objects are specified in kbuild makefile as follows: 372# <composite-object>-objs := <list of .o files> 373# or 374# <composite-object>-y := <list of .o files> 375link_multi_deps = \ 376$(filter $(addprefix $(obj)/, \ 377$($(subst $(obj)/,,$(@:.o=-objs))) \ 378$($(subst $(obj)/,,$(@:.o=-y)))), $^) 379 380quiet_cmd_link_multi-y = LD $@ 381cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis) 382 383quiet_cmd_link_multi-m = LD [M] $@ 384cmd_link_multi-m = $(cmd_link_multi-y) 385 386$(multi-used-y): FORCE 387 $(call if_changed,link_multi-y) 388$(call multi_depend, $(multi-used-y), .o, -objs -y) 389 390$(multi-used-m): FORCE 391 $(call if_changed,link_multi-m) 392 @{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod) 393$(call multi_depend, $(multi-used-m), .o, -objs -y) 394 395targets += $(multi-used-y) $(multi-used-m) 396 397 398# Descending 399# --------------------------------------------------------------------------- 400 401PHONY += $(subdir-ym) 402$(subdir-ym): 403 $(Q)$(MAKE) $(build)=$@ 404 405# Add FORCE to the prequisites of a target to force it to be always rebuilt. 406# --------------------------------------------------------------------------- 407 408PHONY += FORCE 409 410FORCE: 411 412# Read all saved command lines and dependencies for the $(targets) we 413# may be building above, using $(if_changed{,_dep}). As an 414# optimization, we don't need to read them if the target does not 415# exist, we will rebuild anyway in that case. 416 417targets := $(wildcard $(sort $(targets))) 418cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) 419 420ifneq ($(cmd_files),) 421 include $(cmd_files) 422endif 423 424# Declare the contents of the .PHONY variable as phony. We keep that 425# information in a variable se we can use it in if_changed and friends. 426 427.PHONY: $(PHONY) 428