1 # SPDX-License-Identifier: GPL-2.0
9 # To see a list of typical targets execute "make help"
10 # More info can be located in ./README
11 # Comments in this file are targeted only to the developer, do not
12 # expect to learn how to build the kernel reading this file.
14 # That's our default target when none is given on the command line
18 # We are using a recursive build, so we need to do a little thinking
19 # to get the ordering right.
21 # Most importantly: sub-Makefiles should only ever modify files in
22 # their own directory. If in some directory we have a dependency on
23 # a file in another dir (which doesn't happen often, but it's often
24 # unavoidable when linking the built-in.a targets which finally
25 # turn into vmlinux), we will call a sub make in that other dir, and
26 # after that we are sure that everything which is in that other dir
29 # The only cases where we need to modify files which have global
30 # effects are thus separated out and done before the recursive
31 # descending is started. They are now explicitly listed as the
34 ifneq ($(sub_make_done),1)
36 # Do not use make's built-in rules and variables
37 # (this increases performance and avoids hard-to-debug behaviour)
40 # Avoid funny character set dependencies
44 export LC_COLLATE LC_NUMERIC
46 # Avoid interference with shell env settings
50 # ---------------------------------------------------------------------------
52 # Normally, we echo the whole command before executing it. By making
53 # that echo $($(quiet)$(cmd)), we now have the possibility to set
54 # $(quiet) to choose other forms of output instead, e.g.
56 # quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
57 # cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
59 # If $(quiet) is empty, the whole command will be printed.
60 # If it is set to "quiet_", only the short version will be printed.
61 # If it is set to "silent_", nothing will be printed at all, since
62 # the variable $(silent_cmd_cc_o_c) doesn't exist.
64 # A simple variant is to prefix commands with $(Q) - that's useful
65 # for commands that shall be hidden in non-verbose mode.
69 # If KBUILD_VERBOSE equals 0 then the above command will be hidden.
70 # If KBUILD_VERBOSE equals 1 then the above command is displayed.
72 # To put more focus on warnings, be less verbose as default
73 # Use 'make V=1' to see the full commands
75 ifeq ("$(origin V)", "command line")
82 ifeq ($(KBUILD_VERBOSE),1)
90 # If the user is running make -s (silent mode), suppress echoing of
93 ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
97 export quiet Q KBUILD_VERBOSE
99 # Kbuild will save output files in the current working directory.
100 # This does not need to match to the root of the kernel source tree.
102 # For example, you can do this:
104 # cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
106 # If you want to save output files in a different location, there are
107 # two syntaxes to specify it.
110 # Use "make O=dir/to/store/output/files/"
112 # 2) Set KBUILD_OUTPUT
113 # Set the environment variable KBUILD_OUTPUT to point to the output directory.
114 # export KBUILD_OUTPUT=dir/to/store/output/files/; make
116 # The O= assignment takes precedence over the KBUILD_OUTPUT environment
119 # Do we want to change the working directory?
120 ifeq ("$(origin O)", "command line")
121 KBUILD_OUTPUT := $(O)
124 ifneq ($(KBUILD_OUTPUT),)
125 # Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
126 # expand a shell special character '~'. We use a somewhat tedious way here.
127 abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
128 $(if $(abs_objtree),, \
129 $(error failed to create output directory "$(KBUILD_OUTPUT)"))
131 # $(realpath ...) resolves symlinks
132 abs_objtree := $(realpath $(abs_objtree))
134 abs_objtree := $(CURDIR)
135 endif # ifneq ($(KBUILD_OUTPUT),)
137 ifeq ($(abs_objtree),$(CURDIR))
138 # Suppress "Entering directory ..." unless we are changing the work directory.
139 MAKEFLAGS += --no-print-directory
144 abs_srctree := $(realpath $(dir $(lastword $(MAKEFILE_LIST))))
146 ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
147 $(error source directory cannot contain spaces or colons)
150 ifneq ($(abs_srctree),$(abs_objtree))
151 # Look for make include files relative to root of kernel src
153 # This does not become effective immediately because MAKEFLAGS is re-parsed
154 # once after the Makefile is read. We need to invoke sub-make.
155 MAKEFLAGS += --include-dir=$(abs_srctree)
159 ifneq ($(filter 3.%,$(MAKE_VERSION)),)
160 # 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
161 # We need to invoke sub-make to avoid implicit rules in the top Makefile.
163 # Cancel implicit rules for this Makefile.
164 $(lastword $(MAKEFILE_LIST)): ;
167 export abs_srctree abs_objtree
168 export sub_make_done := 1
170 ifeq ($(need-sub-make),1)
172 PHONY += $(MAKECMDGOALS) sub-make
174 $(filter-out _all sub-make $(lastword $(MAKEFILE_LIST)), $(MAKECMDGOALS)) _all: sub-make
177 # Invoke a second make in the output directory, passing relevant variables
179 $(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
181 endif # need-sub-make
182 endif # sub_make_done
184 # We process the rest of the Makefile if this is the final invocation of make
185 ifeq ($(need-sub-make),)
187 # Do not print "Entering directory ...",
188 # but we want to display it when entering to the output directory
189 # so that IDEs/editors are able to understand relative filenames.
190 MAKEFLAGS += --no-print-directory
192 # Call a source code checker (by default, "sparse") as part of the
195 # Use 'make C=1' to enable checking of only re-compiled files.
196 # Use 'make C=2' to enable checking of *all* source files, regardless
197 # of whether they are re-compiled or not.
199 # See the file "Documentation/dev-tools/sparse.rst" for more details,
200 # including where to get the "sparse" utility.
202 ifeq ("$(origin C)", "command line")
203 KBUILD_CHECKSRC = $(C)
205 ifndef KBUILD_CHECKSRC
209 # Use make M=dir to specify directory of external module to build
210 # Old syntax make ... SUBDIRS=$PWD is still supported
211 # Setting the environment variable KBUILD_EXTMOD take precedence
213 $(warning ================= WARNING ================)
214 $(warning 'SUBDIRS' will be removed after Linux 5.3)
216 $(warning If you are building an individual subdirectory)
217 $(warning in the kernel tree, you can do like this:)
218 $(warning $$ make path/to/dir/you/want/to/build/)
219 $(warning (Do not forget the trailing slash))
221 $(warning If you are building an external module,)
222 $(warning Please use 'M=' or 'KBUILD_EXTMOD' instead)
223 $(warning ==========================================)
224 KBUILD_EXTMOD ?= $(SUBDIRS)
227 ifeq ("$(origin M)", "command line")
228 KBUILD_EXTMOD := $(M)
231 export KBUILD_CHECKSRC KBUILD_EXTMOD
233 ifeq ($(abs_srctree),$(abs_objtree))
234 # building in the source tree
236 building_out_of_srctree :=
238 ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
239 # building in a subdirectory of the source tree
242 srctree := $(abs_srctree)
244 building_out_of_srctree := 1
247 ifneq ($(KBUILD_ABS_SRCTREE),)
248 srctree := $(abs_srctree)
254 export building_out_of_srctree srctree objtree VPATH
256 # To make sure we do not include .config for any of the *config targets
257 # catch them early, and hand them over to scripts/kconfig/Makefile
258 # It is allowed to specify more targets when calling make, including
259 # mixing *config targets and build targets.
260 # For example 'make oldconfig all'.
261 # Detect when mixed targets is specified, and make a second invocation
262 # of make so .config is not included in this case either (for *config).
264 version_h := include/generated/uapi/linux/version.h
265 old_version_h := include/linux/version.h
267 clean-targets := %clean mrproper cleandocs
268 no-dot-config-targets := $(clean-targets) \
269 cscope gtags TAGS tags help% %docs check% coccicheck \
270 $(version_h) headers headers_% archheaders archscripts \
271 %asm-generic kernelversion %src-pkg
272 no-sync-config-targets := $(no-dot-config-targets) install %install \
280 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
281 ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
286 ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
287 ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
292 ifneq ($(KBUILD_EXTMOD),)
296 ifeq ($(KBUILD_EXTMOD),)
297 ifneq ($(filter config %config,$(MAKECMDGOALS)),)
299 ifneq ($(words $(MAKECMDGOALS)),1)
305 # For "make -j clean all", "make -j mrproper defconfig all", etc.
306 ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
307 ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
312 # install and modules_install need also be processed one by one
313 ifneq ($(filter install,$(MAKECMDGOALS)),)
314 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
319 ifeq ($(mixed-targets),1)
320 # ===========================================================================
321 # We're called with mixed targets (*config and build targets).
322 # Handle them one by one.
324 PHONY += $(MAKECMDGOALS) __build_one_by_one
326 $(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
331 for i in $(MAKECMDGOALS); do \
332 $(MAKE) -f $(srctree)/Makefile $$i; \
337 include scripts/Kbuild.include
339 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
340 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
341 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
342 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
344 include scripts/subarch.include
346 # Cross compiling and selecting different set of gcc/bin-utils
347 # ---------------------------------------------------------------------------
349 # When performing cross compilation for other architectures ARCH shall be set
350 # to the target architecture. (See arch/* for the possibilities).
351 # ARCH can be set during invocation of make:
353 # Another way is to have ARCH set in the environment.
354 # The default ARCH is the host where make is executed.
356 # CROSS_COMPILE specify the prefix used for all executables used
357 # during compilation. Only gcc and related bin-utils executables
358 # are prefixed with $(CROSS_COMPILE).
359 # CROSS_COMPILE can be set on the command line
360 # make CROSS_COMPILE=ia64-linux-
361 # Alternatively CROSS_COMPILE can be set in the environment.
362 # Default value for CROSS_COMPILE is not to prefix executables
363 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
366 # Architecture as present in compile.h
367 UTS_MACHINE := $(ARCH)
370 # Additional ARCH settings for x86
374 ifeq ($(ARCH),x86_64)
378 # Additional ARCH settings for sparc
379 ifeq ($(ARCH),sparc32)
382 ifeq ($(ARCH),sparc64)
386 # Additional ARCH settings for sh
391 KCONFIG_CONFIG ?= .config
392 export KCONFIG_CONFIG
394 # SHELL used by kbuild
395 CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
396 else if [ -x /bin/bash ]; then echo /bin/bash; \
397 else echo sh; fi ; fi)
399 HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
400 HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
401 HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
405 KBUILD_HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 \
406 -fomit-frame-pointer -std=gnu89 $(HOST_LFS_CFLAGS) \
408 KBUILD_HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
409 KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
410 KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
412 # Make variables (CC, etc...)
413 AS = $(CROSS_COMPILE)as
414 LD = $(CROSS_COMPILE)ld
415 CC = $(CROSS_COMPILE)gcc
417 AR = $(CROSS_COMPILE)ar
418 NM = $(CROSS_COMPILE)nm
419 STRIP = $(CROSS_COMPILE)strip
420 OBJCOPY = $(CROSS_COMPILE)objcopy
421 OBJDUMP = $(CROSS_COMPILE)objdump
426 INSTALLKERNEL := installkernel
427 DEPMOD = /sbin/depmod
434 CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
435 -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
444 # Use USERINCLUDE when you must reference the UAPI directories only.
446 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
447 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
448 -I$(srctree)/include/uapi \
449 -I$(objtree)/include/generated/uapi \
450 -include $(srctree)/include/linux/kconfig.h
452 # Use LINUXINCLUDE when you must reference the include/ directory.
453 # Needed to be compatible with the O= option
455 -I$(srctree)/arch/$(SRCARCH)/include \
456 -I$(objtree)/arch/$(SRCARCH)/include/generated \
457 $(if $(building_out_of_srctree),-I$(srctree)/include) \
458 -I$(objtree)/include \
461 KBUILD_AFLAGS := -D__ASSEMBLY__ -fno-PIE
462 KBUILD_CFLAGS := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
463 -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
464 -Werror=implicit-function-declaration -Werror=implicit-int \
465 -Wno-format-security \
467 KBUILD_CPPFLAGS := -D__KERNEL__
468 KBUILD_AFLAGS_KERNEL :=
469 KBUILD_CFLAGS_KERNEL :=
470 KBUILD_AFLAGS_MODULE := -DMODULE
471 KBUILD_CFLAGS_MODULE := -DMODULE
472 KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
474 GCC_PLUGINS_CFLAGS :=
476 export ARCH SRCARCH CONFIG_SHELL HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE AS LD CC
477 export CPP AR NM STRIP OBJCOPY OBJDUMP PAHOLE KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS
478 export MAKE LEX YACC AWK INSTALLKERNEL PERL PYTHON PYTHON2 PYTHON3 UTS_MACHINE
479 export HOSTCXX KBUILD_HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
481 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
482 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
483 export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN
484 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
485 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
486 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
487 export KBUILD_ARFLAGS
489 # Files to ignore in find ... statements
491 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
492 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
494 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
495 --exclude CVS --exclude .pc --exclude .hg --exclude .git
497 # ===========================================================================
498 # Rules shared between *config targets and build targets
500 # Basic helpers built in scripts/basic/
501 PHONY += scripts_basic
503 $(Q)$(MAKE) $(build)=scripts/basic
504 $(Q)rm -f .tmp_quiet_recordmcount
506 PHONY += outputmakefile
507 # outputmakefile generates a Makefile in the output directory, if using a
508 # separate output directory. This allows convenient use of make in the
510 # At the same time when output Makefile generated, generate .gitignore to
511 # ignore whole output directory
513 ifdef building_out_of_srctree
514 $(Q)ln -fsn $(srctree) source
515 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
516 $(Q)test -e .gitignore || \
517 { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
520 ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
521 ifneq ($(CROSS_COMPILE),)
522 CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE:%-=%))
523 GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
524 CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)
525 GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..)
527 ifneq ($(GCC_TOOLCHAIN),)
528 CLANG_FLAGS += --gcc-toolchain=$(GCC_TOOLCHAIN)
530 ifeq ($(shell $(AS) --version 2>&1 | head -n 1 | grep clang),)
531 CLANG_FLAGS += -no-integrated-as
533 CLANG_FLAGS += -Werror=unknown-warning-option
534 KBUILD_CFLAGS += $(CLANG_FLAGS)
535 KBUILD_AFLAGS += $(CLANG_FLAGS)
539 # The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
540 # Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
541 # CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
542 # and from include/config/auto.conf.cmd to detect the compiler upgrade.
543 CC_VERSION_TEXT = $(shell $(CC) --version 2>/dev/null | head -n 1)
545 ifeq ($(config-targets),1)
546 # ===========================================================================
547 # *config targets only - make sure prerequisites are updated, and descend
548 # in scripts/kconfig to make the *config target
550 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
551 # KBUILD_DEFCONFIG may point out an alternative default configuration
552 # used for 'make defconfig'
553 include arch/$(SRCARCH)/Makefile
554 export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
556 config: scripts_basic outputmakefile FORCE
557 $(Q)$(MAKE) $(build)=scripts/kconfig $@
559 %config: scripts_basic outputmakefile FORCE
560 $(Q)$(MAKE) $(build)=scripts/kconfig $@
563 # ===========================================================================
564 # Build targets only - this includes vmlinux, arch specific targets, clean
565 # targets and others. In general all targets except *config targets.
567 # If building an external module we do not care about the all: rule
568 # but instead _all depend on modules
570 ifeq ($(KBUILD_EXTMOD),)
576 # Decide whether to build built-in, modular, or both.
577 # Normally, just do built-in.
582 # If we have only "make modules", don't compile built-in objects.
583 # When we're building modules with modversions, we need to consider
584 # the built-in objects during the descend as well, in order to
585 # make sure the checksums are up to date before we record them.
587 ifeq ($(MAKECMDGOALS),modules)
588 KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
591 # If we have "make <whatever> modules", compile modules
592 # in addition to whatever we do anyway.
593 # Just "make" or "make all" shall build modules as well
595 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
599 ifeq ($(MAKECMDGOALS),)
603 export KBUILD_MODULES KBUILD_BUILTIN
605 ifeq ($(dot-config),1)
606 include include/config/auto.conf
609 ifeq ($(KBUILD_EXTMOD),)
610 # Objects we will link into vmlinux / subdirs we need to visit
612 drivers-y := drivers/ sound/
613 drivers-$(CONFIG_SAMPLES) += samples/
614 drivers-$(CONFIG_KERNEL_HEADER_TEST) += include/
619 endif # KBUILD_EXTMOD
621 # The all: target is the default when no target is given on the
623 # This allow a user to issue only 'make' to build a kernel including modules
624 # Defaults to vmlinux, but the arch makefile usually adds further targets
627 CFLAGS_GCOV := -fprofile-arcs -ftest-coverage \
628 $(call cc-option,-fno-tree-loop-im) \
629 $(call cc-disable-warning,maybe-uninitialized,)
632 # The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
633 ifdef CONFIG_FUNCTION_TRACER
634 CC_FLAGS_FTRACE := -pg
637 RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
638 RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
639 RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
640 RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
641 RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
642 RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
643 export RETPOLINE_CFLAGS
644 export RETPOLINE_VDSO_CFLAGS
646 # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
647 # values of the respective KBUILD_* variables
651 include arch/$(SRCARCH)/Makefile
653 ifeq ($(dot-config),1)
654 ifeq ($(may-sync-config),1)
655 # Read in dependencies to all Kconfig* files, make sure to run syncconfig if
656 # changes are detected. This should be included after arch/$(SRCARCH)/Makefile
657 # because some architectures define CROSS_COMPILE there.
658 include include/config/auto.conf.cmd
662 @echo >&2 '*** Configuration file "$@" not found!'
664 @echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
665 @echo >&2 '*** "make menuconfig" or "make xconfig").'
669 # The actual configuration files used during the build are stored in
670 # include/generated/ and include/config/. Update them if .config is newer than
671 # include/config/auto.conf (which mirrors .config).
673 # This exploits the 'multi-target pattern rule' trick.
674 # The syncconfig should be executed only once to make all the targets.
675 %/auto.conf %/auto.conf.cmd %/tristate.conf: $(KCONFIG_CONFIG)
676 $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
678 # External modules and some install targets need include/generated/autoconf.h
679 # and include/config/auto.conf but do not care if they are up-to-date.
680 # Use auto.conf to trigger the test
681 PHONY += include/config/auto.conf
683 include/config/auto.conf:
684 $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
686 echo >&2 " ERROR: Kernel configuration is invalid."; \
687 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
688 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
692 endif # may-sync-config
693 endif # $(dot-config)
695 KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
696 KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
697 KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
698 KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
699 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
701 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
707 ifdef CONFIG_CC_DISABLE_WARN_MAYBE_UNINITIALIZED
708 KBUILD_CFLAGS += -Wno-maybe-uninitialized
711 # Tell gcc to never replace conditional load with a non-conditional one
712 KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
714 include scripts/Makefile.kcov
715 include scripts/Makefile.gcc-plugins
717 ifdef CONFIG_READABLE_ASM
718 # Disable optimizations that make assembler listings hard to read.
719 # reorder blocks reorders the control in the function
720 # ipa clone creates specialized cloned functions
721 # partial inlining inlines only parts of functions
722 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
723 $(call cc-option,-fno-ipa-cp-clone,) \
724 $(call cc-option,-fno-partial-inlining)
727 ifneq ($(CONFIG_FRAME_WARN),0)
728 KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
731 stackp-flags-$(CONFIG_CC_HAS_STACKPROTECTOR_NONE) := -fno-stack-protector
732 stackp-flags-$(CONFIG_STACKPROTECTOR) := -fstack-protector
733 stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong
735 KBUILD_CFLAGS += $(stackp-flags-y)
737 ifdef CONFIG_CC_IS_CLANG
738 KBUILD_CPPFLAGS += -Qunused-arguments
739 KBUILD_CFLAGS += -Wno-format-invalid-specifier
740 KBUILD_CFLAGS += -Wno-gnu
741 # Quiet clang warning: comparison of unsigned expression < 0 is always false
742 KBUILD_CFLAGS += -Wno-tautological-compare
743 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
744 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
745 # See modpost pattern 2
746 KBUILD_CFLAGS += -mno-global-merge
749 # These warnings generated too much noise in a regular build.
750 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
751 KBUILD_CFLAGS += -Wno-unused-but-set-variable
754 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
755 ifdef CONFIG_FRAME_POINTER
756 KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
758 # Some targets (ARM with Thumb2, for example), can't be built with frame
759 # pointers. For those, we don't have FUNCTION_TRACER automatically
760 # select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
761 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
762 # -fomit-frame-pointer with FUNCTION_TRACER.
763 ifndef CONFIG_FUNCTION_TRACER
764 KBUILD_CFLAGS += -fomit-frame-pointer
768 # Initialize all stack variables with a pattern, if desired.
769 ifdef CONFIG_INIT_STACK_ALL
770 KBUILD_CFLAGS += -ftrivial-auto-var-init=pattern
773 DEBUG_CFLAGS := $(call cc-option, -fno-var-tracking-assignments)
775 ifdef CONFIG_DEBUG_INFO
776 ifdef CONFIG_DEBUG_INFO_SPLIT
777 DEBUG_CFLAGS += -gsplit-dwarf
781 KBUILD_AFLAGS += -Wa,-gdwarf-2
783 ifdef CONFIG_DEBUG_INFO_DWARF4
784 DEBUG_CFLAGS += -gdwarf-4
787 ifdef CONFIG_DEBUG_INFO_REDUCED
788 DEBUG_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
789 $(call cc-option,-fno-var-tracking)
792 KBUILD_CFLAGS += $(DEBUG_CFLAGS)
795 ifdef CONFIG_FUNCTION_TRACER
796 ifdef CONFIG_FTRACE_MCOUNT_RECORD
797 # gcc 5 supports generating the mcount tables directly
798 ifeq ($(call cc-option-yn,-mrecord-mcount),y)
799 CC_FLAGS_FTRACE += -mrecord-mcount
800 export CC_USING_RECORD_MCOUNT := 1
802 ifdef CONFIG_HAVE_NOP_MCOUNT
803 ifeq ($(call cc-option-yn, -mnop-mcount),y)
804 CC_FLAGS_FTRACE += -mnop-mcount
805 CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
809 ifdef CONFIG_HAVE_FENTRY
810 ifeq ($(call cc-option-yn, -mfentry),y)
811 CC_FLAGS_FTRACE += -mfentry
812 CC_FLAGS_USING += -DCC_USING_FENTRY
815 export CC_FLAGS_FTRACE
816 KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
817 KBUILD_AFLAGS += $(CC_FLAGS_USING)
818 ifdef CONFIG_DYNAMIC_FTRACE
819 ifdef CONFIG_HAVE_C_RECORDMCOUNT
820 BUILD_C_RECORDMCOUNT := y
821 export BUILD_C_RECORDMCOUNT
826 # We trigger additional mismatches with less inlining
827 ifdef CONFIG_DEBUG_SECTION_MISMATCH
828 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
831 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
832 KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
833 LDFLAGS_vmlinux += --gc-sections
836 ifdef CONFIG_LIVEPATCH
837 KBUILD_CFLAGS += $(call cc-option, -flive-patching=inline-clone)
840 # arch Makefile may override CC so keep this after arch Makefile is included
841 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
843 # warn about C99 declaration after statement
844 KBUILD_CFLAGS += -Wdeclaration-after-statement
846 # Warn about unmarked fall-throughs in switch statement.
847 KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough=3,)
849 # Variable Length Arrays (VLAs) should not be used anywhere in the kernel
850 KBUILD_CFLAGS += -Wvla
852 # disable pointer signed / unsigned warnings in gcc 4.0
853 KBUILD_CFLAGS += -Wno-pointer-sign
855 # disable stringop warnings in gcc 8+
856 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
858 # disable invalid "can't wrap" optimizations for signed / pointers
859 KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
861 # clang sets -fmerge-all-constants by default as optimization, but this
862 # is non-conforming behavior for C and in fact breaks the kernel, so we
863 # need to disable it here generally.
864 KBUILD_CFLAGS += $(call cc-option,-fno-merge-all-constants)
866 # for gcc -fno-merge-all-constants disables everything, but it is fine
867 # to have actual conforming behavior enabled.
868 KBUILD_CFLAGS += $(call cc-option,-fmerge-constants)
870 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
871 KBUILD_CFLAGS += $(call cc-option,-fno-stack-check,)
873 # conserve stack if available
874 KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
876 # Prohibit date/time macros, which would make the build non-deterministic
877 KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
879 # enforce correct pointer usage
880 KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
882 # Require designated initializers for all marked structures
883 KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
885 # change __FILE__ to the relative path from the srctree
886 KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
888 # ensure -fcf-protection is disabled when using retpoline as it is
889 # incompatible with -mindirect-branch=thunk-extern
890 ifdef CONFIG_RETPOLINE
891 KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none)
894 # use the deterministic mode of AR if available
895 KBUILD_ARFLAGS := $(call ar-option,D)
897 include scripts/Makefile.kasan
898 include scripts/Makefile.extrawarn
899 include scripts/Makefile.ubsan
901 # Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
903 KBUILD_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS)
904 KBUILD_AFLAGS += $(ARCH_AFLAGS) $(KAFLAGS)
905 KBUILD_CFLAGS += $(ARCH_CFLAGS) $(KCFLAGS)
907 KBUILD_LDFLAGS_MODULE += --build-id
908 LDFLAGS_vmlinux += --build-id
910 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
911 LDFLAGS_vmlinux += $(call ld-option, -X,)
914 # insure the checker run with the right endianness
915 CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
917 # the checker needs the correct machine size
918 CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
920 # Default kernel image to build when no specific target is given.
921 # KBUILD_IMAGE may be overruled on the command line or
922 # set in the environment
923 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
925 export KBUILD_IMAGE ?= vmlinux
928 # INSTALL_PATH specifies where to place the updated kernel and system map
929 # images. Default is /boot, but you can set it to other values
930 export INSTALL_PATH ?= /boot
933 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
934 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
935 # an argument if needed. Otherwise it defaults to the kernel install path
937 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
940 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
941 # relocations required by build roots. This is not defined in the
942 # makefile but the argument can be passed to make if needed.
945 MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
949 # INSTALL_MOD_STRIP, if defined, will cause modules to be
950 # stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
951 # the default option --strip-debug will be used. Otherwise,
952 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
954 ifdef INSTALL_MOD_STRIP
955 ifeq ($(INSTALL_MOD_STRIP),1)
956 mod_strip_cmd = $(STRIP) --strip-debug
958 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
959 endif # INSTALL_MOD_STRIP=1
962 endif # INSTALL_MOD_STRIP
965 # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
966 # after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
967 # or CONFIG_MODULE_COMPRESS_XZ.
969 mod_compress_cmd = true
970 ifdef CONFIG_MODULE_COMPRESS
971 ifdef CONFIG_MODULE_COMPRESS_GZIP
972 mod_compress_cmd = gzip -n -f
973 endif # CONFIG_MODULE_COMPRESS_GZIP
974 ifdef CONFIG_MODULE_COMPRESS_XZ
975 mod_compress_cmd = xz -f
976 endif # CONFIG_MODULE_COMPRESS_XZ
977 endif # CONFIG_MODULE_COMPRESS
978 export mod_compress_cmd
980 ifdef CONFIG_MODULE_SIG_ALL
981 $(eval $(call config_filename,MODULE_SIG_KEY))
983 mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
989 HOST_LIBELF_LIBS = $(shell pkg-config libelf --libs 2>/dev/null || echo -lelf)
991 ifdef CONFIG_STACK_VALIDATION
992 has_libelf := $(call try-run,\
993 echo "int main() {}" | $(HOSTCC) -xc -o /dev/null $(HOST_LIBELF_LIBS) -,1,0)
994 ifeq ($(has_libelf),1)
995 objtool_target := tools/objtool FORCE
997 SKIP_STACK_VALIDATION := 1
998 export SKIP_STACK_VALIDATION
1004 ifeq ($(KBUILD_EXTMOD),)
1005 core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
1007 vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
1008 $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1009 $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
1011 vmlinux-alldirs := $(sort $(vmlinux-dirs) Documentation \
1012 $(patsubst %/,%,$(filter %/, $(init-) $(core-) \
1013 $(drivers-) $(net-) $(libs-) $(virt-))))
1015 init-y := $(patsubst %/, %/built-in.a, $(init-y))
1016 core-y := $(patsubst %/, %/built-in.a, $(core-y))
1017 drivers-y := $(patsubst %/, %/built-in.a, $(drivers-y))
1018 net-y := $(patsubst %/, %/built-in.a, $(net-y))
1019 libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
1020 libs-y2 := $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y)))
1021 virt-y := $(patsubst %/, %/built-in.a, $(virt-y))
1023 # Externally visible symbols (used by link-vmlinux.sh)
1024 export KBUILD_VMLINUX_OBJS := $(head-y) $(init-y) $(core-y) $(libs-y2) \
1025 $(drivers-y) $(net-y) $(virt-y)
1026 export KBUILD_VMLINUX_LIBS := $(libs-y1)
1027 export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
1028 export LDFLAGS_vmlinux
1029 # used by scripts/package/Makefile
1030 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1032 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1034 # Recurse until adjust_autoksyms.sh is satisfied
1035 PHONY += autoksyms_recursive
1036 ifdef CONFIG_TRIM_UNUSED_KSYMS
1037 autoksyms_recursive: $(vmlinux-deps) modules.order
1038 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1039 "$(MAKE) -f $(srctree)/Makefile vmlinux"
1042 # For the kernel to actually contain only the needed exported symbols,
1043 # we have to build modules as well to determine what those symbols are.
1044 # (this can be evaluated only once include/config/auto.conf has been included)
1045 ifdef CONFIG_TRIM_UNUSED_KSYMS
1049 autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1052 $(Q)mkdir -p $(dir $@)
1055 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1057 # Final link of vmlinux with optional arch pass after final link
1058 cmd_link-vmlinux = \
1059 $(CONFIG_SHELL) $< $(LD) $(KBUILD_LDFLAGS) $(LDFLAGS_vmlinux) ; \
1060 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1062 vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1063 +$(call if_changed,link-vmlinux)
1067 # The actual objects are generated when descending,
1068 # make sure no implicit rule kicks in
1069 $(sort $(vmlinux-deps)): $(vmlinux-dirs) ;
1071 # Handle descending into subdirectories listed in $(vmlinux-dirs)
1072 # Preset locale variables to speed up the build process. Limit locale
1073 # tweaks to this spot to avoid wrong language settings when running
1074 # make menuconfig etc.
1075 # Error messages still appears in the original language
1077 PHONY += $(vmlinux-dirs)
1078 $(vmlinux-dirs): prepare
1079 $(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1
1081 filechk_kernel.release = \
1082 echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1084 # Store (new) KERNELRELEASE string in include/config/kernel.release
1085 include/config/kernel.release: FORCE
1086 $(call filechk,kernel.release)
1088 # Additional helpers built in scripts/
1089 # Carefully list dependencies so we do not try to build scripts twice
1092 scripts: scripts_basic scripts_dtc
1093 $(Q)$(MAKE) $(build)=$(@)
1095 # Things we need to do before we recursively start building the kernel
1096 # or the modules are listed in "prepare".
1097 # A multi level approach is used. prepareN is processed before prepareN-1.
1098 # archprepare is used in arch Makefiles and when processed asm symlink,
1099 # version.h and scripts_basic is processed / created.
1101 PHONY += prepare archprepare prepare3
1103 # prepare3 is used to check if we are building in a separate output directory,
1105 # 1) Check that make has not been executed in the kernel src $(srctree)
1106 prepare3: include/config/kernel.release
1107 ifdef building_out_of_srctree
1108 @$(kecho) ' Using $(srctree) as source for kernel'
1109 $(Q)if [ -f $(srctree)/.config -o \
1110 -d $(srctree)/include/config -o \
1111 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
1112 echo >&2 " $(srctree) is not clean, please run 'make ARCH=$(ARCH) mrproper'"; \
1113 echo >&2 " in the '$(srctree)' directory.";\
1118 archprepare: archheaders archscripts scripts prepare3 outputmakefile \
1119 asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h
1121 prepare0: archprepare
1122 $(Q)$(MAKE) $(build)=scripts/mod
1123 $(Q)$(MAKE) $(build)=.
1125 # All the preparing..
1126 prepare: prepare0 prepare-objtool
1128 # Support for using generic headers in asm-generic
1129 asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1131 PHONY += asm-generic uapi-asm-generic
1132 asm-generic: uapi-asm-generic
1133 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1134 generic=include/asm-generic
1136 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1137 generic=include/uapi/asm-generic
1139 PHONY += prepare-objtool
1140 prepare-objtool: $(objtool_target)
1141 ifeq ($(SKIP_STACK_VALIDATION),1)
1142 ifdef CONFIG_UNWINDER_ORC
1143 @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1146 @echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1150 # Generate some files
1151 # ---------------------------------------------------------------------------
1153 # KERNELRELEASE can change from a few different places, meaning version.h
1154 # needs to be updated, so this check is forced on all builds
1157 define filechk_utsrelease.h
1158 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1159 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1162 echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1165 define filechk_version.h
1166 echo \#define LINUX_VERSION_CODE $(shell \
1167 expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
1168 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))'
1172 $(call filechk,version.h)
1173 $(Q)rm -f $(old_version_h)
1175 include/generated/utsrelease.h: include/config/kernel.release FORCE
1176 $(call filechk,utsrelease.h)
1180 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1181 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1183 # ---------------------------------------------------------------------------
1186 #Default location for installed headers
1187 export INSTALL_HDR_PATH = $(objtree)/usr
1189 quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1190 cmd_headers_install = \
1191 mkdir -p $(INSTALL_HDR_PATH); \
1192 rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1193 usr/include $(INSTALL_HDR_PATH)
1195 PHONY += headers_install
1196 headers_install: headers
1197 $(call cmd,headers_install)
1199 PHONY += archheaders archscripts
1201 hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1204 headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1205 $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1206 $(error Headers not exportable for the $(SRCARCH) architecture))
1207 $(Q)$(MAKE) $(hdr-inst)=include/uapi
1208 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1210 PHONY += headers_check
1211 headers_check: headers
1212 $(Q)$(MAKE) $(hdr-inst)=include/uapi HDRCHECK=1
1213 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi HDRCHECK=1
1215 ifdef CONFIG_HEADERS_INSTALL
1219 ifdef CONFIG_HEADERS_CHECK
1223 PHONY += scripts_unifdef
1224 scripts_unifdef: scripts_basic
1225 $(Q)$(MAKE) $(build)=scripts scripts/unifdef
1227 # ---------------------------------------------------------------------------
1232 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1234 PHONY += kselftest-clean
1236 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests clean
1238 PHONY += kselftest-merge
1240 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1241 $(Q)find $(srctree)/tools/testing/selftests -name config | \
1242 xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1243 +$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1245 # ---------------------------------------------------------------------------
1248 ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1249 dtstree := arch/$(SRCARCH)/boot/dts
1254 %.dtb: prepare3 scripts_dtc
1255 $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1257 PHONY += dtbs dtbs_install dt_binding_check
1258 dtbs dtbs_check: prepare3 scripts_dtc
1259 $(Q)$(MAKE) $(build)=$(dtstree)
1261 dtbs_check: export CHECK_DTBS=1
1262 dtbs_check: dt_binding_check
1265 $(Q)$(MAKE) $(dtbinst)=$(dtstree)
1267 ifdef CONFIG_OF_EARLY_FLATTREE
1273 PHONY += scripts_dtc
1274 scripts_dtc: scripts_basic
1275 $(Q)$(MAKE) $(build)=scripts/dtc
1277 dt_binding_check: scripts_dtc
1278 $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1280 # ---------------------------------------------------------------------------
1283 ifdef CONFIG_MODULES
1285 # By default, build modules as well
1291 # A module can be listed more than once in obj-m resulting in
1292 # duplicate lines in modules.order files. Those are removed
1293 # using awk while concatenating to the final file.
1296 modules: $(if $(KBUILD_BUILTIN),vmlinux) modules.order modules.builtin
1297 @$(kecho) ' Building modules, stage 2.';
1298 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1299 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh
1301 modules.order: $(vmlinux-dirs)
1302 $(Q)$(AWK) '!x[$$0]++' $(addsuffix /$@, $(vmlinux-dirs)) > $@
1304 modbuiltin-dirs := $(addprefix _modbuiltin_, $(vmlinux-dirs))
1306 modules.builtin: $(modbuiltin-dirs)
1307 $(Q)$(AWK) '!x[$$0]++' $(addsuffix /$@, $(vmlinux-dirs)) > $@
1309 PHONY += $(modbuiltin-dirs)
1310 # tristate.conf is not included from this Makefile. Add it as a prerequisite
1311 # here to make it self-healing in case somebody accidentally removes it.
1312 $(modbuiltin-dirs): include/config/tristate.conf
1313 $(Q)$(MAKE) $(modbuiltin)=$(patsubst _modbuiltin_%,%,$@)
1315 # Target to prepare building external modules
1316 PHONY += modules_prepare
1317 modules_prepare: prepare
1319 # Target to install modules
1320 PHONY += modules_install
1321 modules_install: _modinst_ _modinst_post
1325 @rm -rf $(MODLIB)/kernel
1326 @rm -f $(MODLIB)/source
1327 @mkdir -p $(MODLIB)/kernel
1328 @ln -s $(abspath $(srctree)) $(MODLIB)/source
1329 @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
1330 rm -f $(MODLIB)/build ; \
1331 ln -s $(CURDIR) $(MODLIB)/build ; \
1333 @sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1334 @sed 's:^:kernel/:' modules.builtin > $(MODLIB)/modules.builtin
1335 @cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1336 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1338 # This depmod is only for convenience to give the initial
1339 # boot a modules.dep even before / is mounted read-write. However the
1340 # boot script depmod is the master version.
1341 PHONY += _modinst_post
1342 _modinst_post: _modinst_
1345 ifeq ($(CONFIG_MODULE_SIG), y)
1346 PHONY += modules_sign
1348 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1351 else # CONFIG_MODULES
1353 # Modules not configured
1354 # ---------------------------------------------------------------------------
1356 PHONY += modules modules_install
1357 modules modules_install:
1359 @echo >&2 "The present kernel configuration has modules disabled."
1360 @echo >&2 "Type 'make config' and enable loadable module support."
1361 @echo >&2 "Then build a kernel with module support enabled."
1365 endif # CONFIG_MODULES
1368 # Cleaning is done on three levels.
1369 # make clean Delete most generated files
1370 # Leave enough to build external modules
1371 # make mrproper Delete the current configuration, and all generated files
1372 # make distclean Remove editor backup files, patch leftover files and the like
1374 # Directories & files removed with 'make clean'
1375 CLEAN_DIRS += include/ksym
1376 CLEAN_FILES += modules.builtin.modinfo
1378 # Directories & files removed with 'make mrproper'
1379 MRPROPER_DIRS += include/config include/generated \
1380 arch/$(SRCARCH)/include/generated .tmp_objdiff
1381 MRPROPER_FILES += .config .config.old .version \
1383 signing_key.pem signing_key.priv signing_key.x509 \
1384 x509.genkey extra_certificates signing_key.x509.keyid \
1385 signing_key.x509.signer vmlinux-gdb.py
1387 # Directories & files removed with 'make distclean'
1389 DISTCLEAN_FILES += tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS
1391 # clean - Delete most, but leave enough to build external modules
1393 clean: rm-dirs := $(CLEAN_DIRS)
1394 clean: rm-files := $(CLEAN_FILES)
1395 clean-dirs := $(addprefix _clean_, . $(vmlinux-alldirs))
1397 PHONY += $(clean-dirs) clean archclean vmlinuxclean
1399 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1402 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1403 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1405 clean: archclean vmlinuxclean
1407 # mrproper - Delete all generated files, including .config
1409 mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS))
1410 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1411 mrproper-dirs := $(addprefix _mrproper_,scripts)
1413 PHONY += $(mrproper-dirs) mrproper
1415 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1417 mrproper: clean $(mrproper-dirs)
1423 distclean: rm-dirs := $(wildcard $(DISTCLEAN_DIRS))
1424 distclean: rm-files := $(wildcard $(DISTCLEAN_FILES))
1431 @find $(srctree) $(RCS_FIND_IGNORE) \
1432 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1433 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1434 -o -name 'core' \) \
1435 -type f -print | xargs rm -f
1438 # Packaging of the kernel to various formats
1439 # ---------------------------------------------------------------------------
1440 package-dir := scripts/package
1443 $(Q)$(MAKE) $(build)=$(package-dir) $@
1444 %pkg: include/config/kernel.release FORCE
1445 $(Q)$(MAKE) $(build)=$(package-dir) $@
1448 # Brief documentation of the typical targets used
1449 # ---------------------------------------------------------------------------
1451 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1452 boards := $(sort $(notdir $(boards)))
1453 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1454 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1458 @echo 'Cleaning targets:'
1459 @echo ' clean - Remove most generated files but keep the config and'
1460 @echo ' enough build support to build external modules'
1461 @echo ' mrproper - Remove all generated files + config + various backup files'
1462 @echo ' distclean - mrproper + remove editor backup and patch files'
1464 @echo 'Configuration targets:'
1465 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1467 @echo 'Other generic targets:'
1468 @echo ' all - Build all targets marked with [*]'
1469 @echo '* vmlinux - Build the bare kernel'
1470 @echo '* modules - Build all modules'
1471 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1472 @echo ' dir/ - Build all files in dir and below'
1473 @echo ' dir/file.[ois] - Build specified target only'
1474 @echo ' dir/file.ll - Build the LLVM assembly file'
1475 @echo ' (requires compiler support for LLVM assembly generation)'
1476 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1477 @echo ' (requires a recent binutils and recent build (System.map))'
1478 @echo ' dir/file.ko - Build module including final link'
1479 @echo ' modules_prepare - Set up for building external modules'
1480 @echo ' tags/TAGS - Generate tags file for editors'
1481 @echo ' cscope - Generate cscope index'
1482 @echo ' gtags - Generate GNU GLOBAL index'
1483 @echo ' kernelrelease - Output the release version string (use with make -s)'
1484 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1485 @echo ' image_name - Output the image name (use with make -s)'
1486 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1487 echo ' (default: $(INSTALL_HDR_PATH))'; \
1489 @echo 'Static analysers:'
1490 @echo ' checkstack - Generate a list of stack hogs'
1491 @echo ' namespacecheck - Name space analysis on compiled kernel'
1492 @echo ' versioncheck - Sanity check on version.h usage'
1493 @echo ' includecheck - Check for duplicate included header files'
1494 @echo ' export_report - List the usages of all exported symbols'
1495 @echo ' headers_check - Sanity check on exported headers'
1496 @echo ' headerdep - Detect inclusion cycles in headers'
1497 @echo ' coccicheck - Check with Coccinelle'
1499 @echo 'Kernel selftest:'
1500 @echo ' kselftest - Build and run kernel selftest (run as root)'
1501 @echo ' Build, install, and boot kernel before'
1502 @echo ' running kselftest on it'
1503 @echo ' kselftest-clean - Remove all generated kselftest files'
1504 @echo ' kselftest-merge - Merge all the config dependencies of kselftest to existing'
1508 echo 'Devicetree:'; \
1509 echo '* dtbs - Build device tree blobs for enabled boards'; \
1510 echo ' dtbs_install - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1513 @echo 'Userspace tools targets:'
1514 @echo ' use "make tools/help"'
1515 @echo ' or "cd tools; make help"'
1517 @echo 'Kernel packaging:'
1518 @$(MAKE) $(build)=$(package-dir) help
1520 @echo 'Documentation targets:'
1521 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1523 @echo 'Architecture specific targets ($(SRCARCH)):'
1524 @$(if $(archhelp),$(archhelp),\
1525 echo ' No architecture specific help defined for $(SRCARCH)')
1528 $(foreach b, $(boards), \
1529 printf " %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1531 @$(if $(board-dirs), \
1532 $(foreach b, $(board-dirs), \
1533 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1534 printf " %-16s - Show all of the above\\n" help-boards; \
1537 @echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1538 @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
1539 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1540 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK (sparse by default)'
1541 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1542 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1543 @echo ' make W=n [targets] Enable extra gcc checks, n=1,2,3 where'
1544 @echo ' 1: warnings which may be relevant and do not occur too often'
1545 @echo ' 2: warnings which occur quite often but may still be relevant'
1546 @echo ' 3: more obscure warnings, can most likely be ignored'
1547 @echo ' Multiple levels can be combined with W=12 or W=123'
1549 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1550 @echo 'For further info see the ./README file'
1553 help-board-dirs := $(addprefix help-,$(board-dirs))
1555 help-boards: $(help-board-dirs)
1557 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1559 $(help-board-dirs): help-%:
1560 @echo 'Architecture specific targets ($(SRCARCH) $*):'
1561 @$(if $(boards-per-dir), \
1562 $(foreach b, $(boards-per-dir), \
1563 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1567 # Documentation targets
1568 # ---------------------------------------------------------------------------
1569 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1570 linkcheckdocs dochelp refcheckdocs
1571 PHONY += $(DOC_TARGETS)
1572 $(DOC_TARGETS): scripts_basic FORCE
1573 $(Q)$(MAKE) $(build)=Documentation $@
1576 # ---------------------------------------------------------------------------
1578 PHONY += scripts_gdb
1579 scripts_gdb: prepare0
1580 $(Q)$(MAKE) $(build)=scripts/gdb
1581 $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1583 ifdef CONFIG_GDB_SCRIPTS
1587 else # KBUILD_EXTMOD
1590 # External module support.
1591 # When building external modules the kernel used as basis is considered
1592 # read-only, and no consistency checks are made and the make
1593 # system is not used on the basis kernel. If updates are required
1594 # in the basis kernel ordinary make commands (without M=...) must
1597 # The following are the only valid targets when building external
1599 # make M=dir clean Delete all automatically generated files
1600 # make M=dir modules Make all modules in specified dir
1601 # make M=dir Same as 'make M=dir modules'
1602 # make M=dir modules_install
1603 # Install the modules built in the module directory
1604 # Assumes install directory is already created
1606 # We are always building modules
1609 PHONY += $(objtree)/Module.symvers
1610 $(objtree)/Module.symvers:
1611 @test -e $(objtree)/Module.symvers || ( \
1613 echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1614 echo " is missing; modules will have no dependencies and modversions."; \
1617 module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
1618 PHONY += $(module-dirs) modules
1619 $(module-dirs): prepare $(objtree)/Module.symvers
1620 $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@) need-modorder=1
1622 modules: $(module-dirs)
1623 @$(kecho) ' Building modules, stage 2.';
1624 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1626 PHONY += modules_install
1627 modules_install: _emodinst_ _emodinst_post
1629 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1632 $(Q)mkdir -p $(MODLIB)/$(install-dir)
1633 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1635 PHONY += _emodinst_post
1636 _emodinst_post: _emodinst_
1639 clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))
1641 PHONY += $(clean-dirs) clean
1643 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1645 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1649 @echo ' Building external modules.'
1650 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1652 @echo ' modules - default target, build the module(s)'
1653 @echo ' modules_install - install the module'
1654 @echo ' clean - remove generated files in module directory only'
1658 endif # KBUILD_EXTMOD
1660 clean: $(clean-dirs)
1663 @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1664 \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1666 -o -name '*.dtb' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1667 -o -name '*.dwo' -o -name '*.lst' \
1668 -o -name '*.su' -o -name '*.mod' \
1669 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1670 -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1671 -o -name '*.asn1.[ch]' \
1672 -o -name '*.symtypes' -o -name 'modules.order' \
1673 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1674 -o -name '*.c.[012]*.*' \
1676 -o -name '*.gcno' \) -type f -print | xargs rm -f
1678 # Generate tags for editors
1679 # ---------------------------------------------------------------------------
1680 quiet_cmd_tags = GEN $@
1681 cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
1683 tags TAGS cscope gtags: FORCE
1686 # Scripts to check various things for consistency
1687 # ---------------------------------------------------------------------------
1689 PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1692 find $(srctree)/* $(RCS_FIND_IGNORE) \
1693 -name '*.[hcS]' -type f -print | sort \
1694 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1697 find $(srctree)/* $(RCS_FIND_IGNORE) \
1698 -name '*.[hcS]' -type f -print | sort \
1699 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1702 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1705 $(PERL) $(srctree)/scripts/namespace.pl
1708 $(PERL) $(srctree)/scripts/export_report.pl
1710 PHONY += checkstack kernelrelease kernelversion image_name
1712 # UML needs a little special treatment here. It wants to use the host
1713 # toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
1714 # else wants $(ARCH), including people doing cross-builds, which means
1715 # that $(SUBARCH) doesn't work here.
1717 CHECKSTACK_ARCH := $(SUBARCH)
1719 CHECKSTACK_ARCH := $(ARCH)
1722 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1723 $(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1726 @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1729 @echo $(KERNELVERSION)
1732 @echo $(KBUILD_IMAGE)
1734 # Clear a bunch of variables before executing the submake
1736 ifeq ($(quiet),silent_)
1741 $(Q)mkdir -p $(objtree)/tools
1742 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1745 $(Q)mkdir -p $(objtree)/tools
1746 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1749 # ---------------------------------------------------------------------------
1750 # Single targets are compatible with:
1751 # - build with mixed source and output
1752 # - build with separate output dir 'make O=...'
1753 # - external modules
1755 # target-dir => where to store outputfile
1756 # build-dir => directory in kernel source tree to use
1758 build-target = $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD)/)$@
1759 build-dir = $(patsubst %/,%,$(dir $(build-target)))
1762 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1764 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1765 %.lst: prepare FORCE
1766 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1768 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1770 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1771 %.symtypes: prepare FORCE
1772 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1779 $(Q)$(MAKE) KBUILD_MODULES=1 $(build)=$(build-dir)
1781 # FIXME Should go into a make.lib or something
1782 # ===========================================================================
1784 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs)))
1785 cmd_rmdirs = rm -rf $(rm-dirs)
1787 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
1788 cmd_rmfiles = rm -f $(rm-files)
1790 # Run depmod only if we have System.map and depmod is executable
1791 quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
1792 cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1795 # read saved command lines for existing targets
1796 existing-targets := $(wildcard $(sort $(targets)))
1798 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1800 endif # ifeq ($(config-targets),1)
1801 endif # ifeq ($(mixed-targets),1)
1802 endif # need-sub-make
1807 # Declare the contents of the PHONY variable as phony. We keep that
1808 # information in a variable so we can use it in if_changed and friends.