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 extmod-prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
235 ifeq ($(abs_srctree),$(abs_objtree))
236 # building in the source tree
238 building_out_of_srctree :=
240 ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
241 # building in a subdirectory of the source tree
244 srctree := $(abs_srctree)
246 building_out_of_srctree := 1
249 ifneq ($(KBUILD_ABS_SRCTREE),)
250 srctree := $(abs_srctree)
256 export building_out_of_srctree srctree objtree VPATH
258 # To make sure we do not include .config for any of the *config targets
259 # catch them early, and hand them over to scripts/kconfig/Makefile
260 # It is allowed to specify more targets when calling make, including
261 # mixing *config targets and build targets.
262 # For example 'make oldconfig all'.
263 # Detect when mixed targets is specified, and make a second invocation
264 # of make so .config is not included in this case either (for *config).
266 version_h := include/generated/uapi/linux/version.h
267 old_version_h := include/linux/version.h
269 clean-targets := %clean mrproper cleandocs
270 no-dot-config-targets := $(clean-targets) \
271 cscope gtags TAGS tags help% %docs check% coccicheck \
272 $(version_h) headers headers_% archheaders archscripts \
273 %asm-generic kernelversion %src-pkg
274 no-sync-config-targets := $(no-dot-config-targets) install %install \
276 single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/
284 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
285 ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
290 ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
291 ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
296 ifneq ($(KBUILD_EXTMOD),)
300 ifeq ($(KBUILD_EXTMOD),)
301 ifneq ($(filter config %config,$(MAKECMDGOALS)),)
303 ifneq ($(words $(MAKECMDGOALS)),1)
309 # We cannot build single targets and the others at the same time
310 ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
312 ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
317 # For "make -j clean all", "make -j mrproper defconfig all", etc.
318 ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
319 ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
324 # install and modules_install need also be processed one by one
325 ifneq ($(filter install,$(MAKECMDGOALS)),)
326 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
332 # ===========================================================================
333 # We're called with mixed targets (*config and build targets).
334 # Handle them one by one.
336 PHONY += $(MAKECMDGOALS) __build_one_by_one
338 $(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
343 for i in $(MAKECMDGOALS); do \
344 $(MAKE) -f $(srctree)/Makefile $$i; \
349 include scripts/Kbuild.include
351 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
352 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
353 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
354 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
356 include scripts/subarch.include
358 # Cross compiling and selecting different set of gcc/bin-utils
359 # ---------------------------------------------------------------------------
361 # When performing cross compilation for other architectures ARCH shall be set
362 # to the target architecture. (See arch/* for the possibilities).
363 # ARCH can be set during invocation of make:
365 # Another way is to have ARCH set in the environment.
366 # The default ARCH is the host where make is executed.
368 # CROSS_COMPILE specify the prefix used for all executables used
369 # during compilation. Only gcc and related bin-utils executables
370 # are prefixed with $(CROSS_COMPILE).
371 # CROSS_COMPILE can be set on the command line
372 # make CROSS_COMPILE=ia64-linux-
373 # Alternatively CROSS_COMPILE can be set in the environment.
374 # Default value for CROSS_COMPILE is not to prefix executables
375 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
378 # Architecture as present in compile.h
379 UTS_MACHINE := $(ARCH)
382 # Additional ARCH settings for x86
386 ifeq ($(ARCH),x86_64)
390 # Additional ARCH settings for sparc
391 ifeq ($(ARCH),sparc32)
394 ifeq ($(ARCH),sparc64)
398 # Additional ARCH settings for sh
403 KCONFIG_CONFIG ?= .config
404 export KCONFIG_CONFIG
406 # SHELL used by kbuild
409 HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
410 HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
411 HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
415 KBUILD_HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 \
416 -fomit-frame-pointer -std=gnu89 $(HOST_LFS_CFLAGS) \
418 KBUILD_HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
419 KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
420 KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
422 # Make variables (CC, etc...)
423 AS = $(CROSS_COMPILE)as
424 LD = $(CROSS_COMPILE)ld
425 CC = $(CROSS_COMPILE)gcc
427 AR = $(CROSS_COMPILE)ar
428 NM = $(CROSS_COMPILE)nm
429 STRIP = $(CROSS_COMPILE)strip
430 OBJCOPY = $(CROSS_COMPILE)objcopy
431 OBJDUMP = $(CROSS_COMPILE)objdump
432 OBJSIZE = $(CROSS_COMPILE)size
437 INSTALLKERNEL := installkernel
438 DEPMOD = /sbin/depmod
446 CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
447 -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
456 # Use USERINCLUDE when you must reference the UAPI directories only.
458 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
459 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
460 -I$(srctree)/include/uapi \
461 -I$(objtree)/include/generated/uapi \
462 -include $(srctree)/include/linux/kconfig.h
464 # Use LINUXINCLUDE when you must reference the include/ directory.
465 # Needed to be compatible with the O= option
467 -I$(srctree)/arch/$(SRCARCH)/include \
468 -I$(objtree)/arch/$(SRCARCH)/include/generated \
469 $(if $(building_out_of_srctree),-I$(srctree)/include) \
470 -I$(objtree)/include \
473 KBUILD_AFLAGS := -D__ASSEMBLY__ -fno-PIE
474 KBUILD_CFLAGS := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
475 -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
476 -Werror=implicit-function-declaration -Werror=implicit-int \
477 -Wno-format-security \
479 KBUILD_CPPFLAGS := -D__KERNEL__
480 KBUILD_AFLAGS_KERNEL :=
481 KBUILD_CFLAGS_KERNEL :=
482 KBUILD_AFLAGS_MODULE := -DMODULE
483 KBUILD_CFLAGS_MODULE := -DMODULE
484 KBUILD_LDFLAGS_MODULE :=
485 export KBUILD_LDS_MODULE := $(srctree)/scripts/module-common.lds
487 GCC_PLUGINS_CFLAGS :=
490 export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE AS LD CC
491 export CPP AR NM STRIP OBJCOPY OBJDUMP OBJSIZE PAHOLE LEX YACC AWK INSTALLKERNEL
492 export PERL PYTHON PYTHON2 PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
493 export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
495 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
496 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
497 export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN
498 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
499 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
500 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
501 export KBUILD_ARFLAGS
503 # Files to ignore in find ... statements
505 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
506 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
508 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
509 --exclude CVS --exclude .pc --exclude .hg --exclude .git
511 # ===========================================================================
512 # Rules shared between *config targets and build targets
514 # Basic helpers built in scripts/basic/
515 PHONY += scripts_basic
517 $(Q)$(MAKE) $(build)=scripts/basic
518 $(Q)rm -f .tmp_quiet_recordmcount
520 PHONY += outputmakefile
521 # Before starting out-of-tree build, make sure the source tree is clean.
522 # outputmakefile generates a Makefile in the output directory, if using a
523 # separate output directory. This allows convenient use of make in the
525 # At the same time when output Makefile generated, generate .gitignore to
526 # ignore whole output directory
528 ifdef building_out_of_srctree
529 $(Q)if [ -f $(srctree)/.config -o \
530 -d $(srctree)/include/config -o \
531 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
533 echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
534 echo >&2 "*** in $(abs_srctree)";\
538 $(Q)ln -fsn $(srctree) source
539 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
540 $(Q)test -e .gitignore || \
541 { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
544 ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
545 ifneq ($(CROSS_COMPILE),)
546 CLANG_FLAGS += --target=$(notdir $(CROSS_COMPILE:%-=%))
547 GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
548 CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)
549 GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..)
551 ifneq ($(GCC_TOOLCHAIN),)
552 CLANG_FLAGS += --gcc-toolchain=$(GCC_TOOLCHAIN)
554 ifeq ($(shell $(AS) --version 2>&1 | head -n 1 | grep clang),)
555 CLANG_FLAGS += -no-integrated-as
557 CLANG_FLAGS += -Werror=unknown-warning-option
558 KBUILD_CFLAGS += $(CLANG_FLAGS)
559 KBUILD_AFLAGS += $(CLANG_FLAGS)
563 # The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
564 # Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
565 # CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
566 # and from include/config/auto.conf.cmd to detect the compiler upgrade.
567 CC_VERSION_TEXT = $(shell $(CC) --version 2>/dev/null | head -n 1)
570 # ===========================================================================
571 # *config targets only - make sure prerequisites are updated, and descend
572 # in scripts/kconfig to make the *config target
574 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
575 # KBUILD_DEFCONFIG may point out an alternative default configuration
576 # used for 'make defconfig'
577 include arch/$(SRCARCH)/Makefile
578 export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
580 config: outputmakefile scripts_basic FORCE
581 $(Q)$(MAKE) $(build)=scripts/kconfig $@
583 %config: outputmakefile scripts_basic FORCE
584 $(Q)$(MAKE) $(build)=scripts/kconfig $@
587 # ===========================================================================
588 # Build targets only - this includes vmlinux, arch specific targets, clean
589 # targets and others. In general all targets except *config targets.
591 # If building an external module we do not care about the all: rule
592 # but instead _all depend on modules
594 ifeq ($(KBUILD_EXTMOD),)
600 # Decide whether to build built-in, modular, or both.
601 # Normally, just do built-in.
606 # If we have only "make modules", don't compile built-in objects.
607 # When we're building modules with modversions, we need to consider
608 # the built-in objects during the descend as well, in order to
609 # make sure the checksums are up to date before we record them.
611 ifeq ($(MAKECMDGOALS),modules)
612 KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
615 # If we have "make <whatever> modules", compile modules
616 # in addition to whatever we do anyway.
617 # Just "make" or "make all" shall build modules as well
619 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
623 ifeq ($(MAKECMDGOALS),)
627 export KBUILD_MODULES KBUILD_BUILTIN
630 include include/config/auto.conf
633 ifeq ($(KBUILD_EXTMOD),)
634 # Objects we will link into vmlinux / subdirs we need to visit
636 drivers-y := drivers/ sound/
637 drivers-$(CONFIG_SAMPLES) += samples/
638 drivers-$(CONFIG_KERNEL_HEADER_TEST) += include/
643 endif # KBUILD_EXTMOD
645 # The all: target is the default when no target is given on the
647 # This allow a user to issue only 'make' to build a kernel including modules
648 # Defaults to vmlinux, but the arch makefile usually adds further targets
651 CFLAGS_GCOV := -fprofile-arcs -ftest-coverage \
652 $(call cc-option,-fno-tree-loop-im) \
653 $(call cc-disable-warning,maybe-uninitialized,)
656 # The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
657 ifdef CONFIG_FUNCTION_TRACER
658 CC_FLAGS_FTRACE := -pg
661 RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
662 RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
663 RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
664 RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
665 RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
666 RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
667 export RETPOLINE_CFLAGS
668 export RETPOLINE_VDSO_CFLAGS
670 include arch/$(SRCARCH)/Makefile
673 ifdef may-sync-config
674 # Read in dependencies to all Kconfig* files, make sure to run syncconfig if
675 # changes are detected. This should be included after arch/$(SRCARCH)/Makefile
676 # because some architectures define CROSS_COMPILE there.
677 include include/config/auto.conf.cmd
681 @echo >&2 '*** Configuration file "$@" not found!'
683 @echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
684 @echo >&2 '*** "make menuconfig" or "make xconfig").'
688 # The actual configuration files used during the build are stored in
689 # include/generated/ and include/config/. Update them if .config is newer than
690 # include/config/auto.conf (which mirrors .config).
692 # This exploits the 'multi-target pattern rule' trick.
693 # The syncconfig should be executed only once to make all the targets.
694 %/auto.conf %/auto.conf.cmd %/tristate.conf: $(KCONFIG_CONFIG)
695 $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
696 else # !may-sync-config
697 # External modules and some install targets need include/generated/autoconf.h
698 # and include/config/auto.conf but do not care if they are up-to-date.
699 # Use auto.conf to trigger the test
700 PHONY += include/config/auto.conf
702 include/config/auto.conf:
703 $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
705 echo >&2 " ERROR: Kernel configuration is invalid."; \
706 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
707 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
711 endif # may-sync-config
714 KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
715 KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
716 KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
717 KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
718 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
720 ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
722 else ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3
724 else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
728 ifdef CONFIG_CC_DISABLE_WARN_MAYBE_UNINITIALIZED
729 KBUILD_CFLAGS += -Wno-maybe-uninitialized
732 # Tell gcc to never replace conditional load with a non-conditional one
733 KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
735 include scripts/Makefile.kcov
736 include scripts/Makefile.gcc-plugins
738 ifdef CONFIG_READABLE_ASM
739 # Disable optimizations that make assembler listings hard to read.
740 # reorder blocks reorders the control in the function
741 # ipa clone creates specialized cloned functions
742 # partial inlining inlines only parts of functions
743 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
744 $(call cc-option,-fno-ipa-cp-clone,) \
745 $(call cc-option,-fno-partial-inlining)
748 ifneq ($(CONFIG_FRAME_WARN),0)
749 KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
752 stackp-flags-$(CONFIG_CC_HAS_STACKPROTECTOR_NONE) := -fno-stack-protector
753 stackp-flags-$(CONFIG_STACKPROTECTOR) := -fstack-protector
754 stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong
756 KBUILD_CFLAGS += $(stackp-flags-y)
758 ifdef CONFIG_CC_IS_CLANG
759 KBUILD_CPPFLAGS += -Qunused-arguments
760 KBUILD_CFLAGS += -Wno-format-invalid-specifier
761 KBUILD_CFLAGS += -Wno-gnu
762 # Quiet clang warning: comparison of unsigned expression < 0 is always false
763 KBUILD_CFLAGS += -Wno-tautological-compare
764 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
765 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
766 # See modpost pattern 2
767 KBUILD_CFLAGS += -mno-global-merge
770 # These warnings generated too much noise in a regular build.
771 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
772 KBUILD_CFLAGS += -Wno-unused-but-set-variable
774 # Warn about unmarked fall-throughs in switch statement.
775 # Disabled for clang while comment to attribute conversion happens and
776 # https://github.com/ClangBuiltLinux/linux/issues/636 is discussed.
777 KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough,)
780 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
781 ifdef CONFIG_FRAME_POINTER
782 KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
784 # Some targets (ARM with Thumb2, for example), can't be built with frame
785 # pointers. For those, we don't have FUNCTION_TRACER automatically
786 # select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
787 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
788 # -fomit-frame-pointer with FUNCTION_TRACER.
789 ifndef CONFIG_FUNCTION_TRACER
790 KBUILD_CFLAGS += -fomit-frame-pointer
794 # Initialize all stack variables with a pattern, if desired.
795 ifdef CONFIG_INIT_STACK_ALL
796 KBUILD_CFLAGS += -ftrivial-auto-var-init=pattern
799 DEBUG_CFLAGS := $(call cc-option, -fno-var-tracking-assignments)
801 ifdef CONFIG_DEBUG_INFO
802 ifdef CONFIG_DEBUG_INFO_SPLIT
803 DEBUG_CFLAGS += -gsplit-dwarf
807 KBUILD_AFLAGS += -Wa,-gdwarf-2
809 ifdef CONFIG_DEBUG_INFO_DWARF4
810 DEBUG_CFLAGS += -gdwarf-4
813 ifdef CONFIG_DEBUG_INFO_REDUCED
814 DEBUG_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
815 $(call cc-option,-fno-var-tracking)
818 KBUILD_CFLAGS += $(DEBUG_CFLAGS)
821 ifdef CONFIG_FUNCTION_TRACER
822 ifdef CONFIG_FTRACE_MCOUNT_RECORD
823 # gcc 5 supports generating the mcount tables directly
824 ifeq ($(call cc-option-yn,-mrecord-mcount),y)
825 CC_FLAGS_FTRACE += -mrecord-mcount
826 export CC_USING_RECORD_MCOUNT := 1
828 ifdef CONFIG_HAVE_NOP_MCOUNT
829 ifeq ($(call cc-option-yn, -mnop-mcount),y)
830 CC_FLAGS_FTRACE += -mnop-mcount
831 CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
835 ifdef CONFIG_HAVE_FENTRY
836 ifeq ($(call cc-option-yn, -mfentry),y)
837 CC_FLAGS_FTRACE += -mfentry
838 CC_FLAGS_USING += -DCC_USING_FENTRY
841 export CC_FLAGS_FTRACE
842 KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
843 KBUILD_AFLAGS += $(CC_FLAGS_USING)
844 ifdef CONFIG_DYNAMIC_FTRACE
845 ifdef CONFIG_HAVE_C_RECORDMCOUNT
846 BUILD_C_RECORDMCOUNT := y
847 export BUILD_C_RECORDMCOUNT
852 # We trigger additional mismatches with less inlining
853 ifdef CONFIG_DEBUG_SECTION_MISMATCH
854 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
857 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
858 KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
859 LDFLAGS_vmlinux += --gc-sections
862 ifdef CONFIG_LIVEPATCH
863 KBUILD_CFLAGS += $(call cc-option, -flive-patching=inline-clone)
866 # arch Makefile may override CC so keep this after arch Makefile is included
867 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
869 # warn about C99 declaration after statement
870 KBUILD_CFLAGS += -Wdeclaration-after-statement
872 # Variable Length Arrays (VLAs) should not be used anywhere in the kernel
873 KBUILD_CFLAGS += -Wvla
875 # disable pointer signed / unsigned warnings in gcc 4.0
876 KBUILD_CFLAGS += -Wno-pointer-sign
878 # disable stringop warnings in gcc 8+
879 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
881 # disable invalid "can't wrap" optimizations for signed / pointers
882 KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
884 # clang sets -fmerge-all-constants by default as optimization, but this
885 # is non-conforming behavior for C and in fact breaks the kernel, so we
886 # need to disable it here generally.
887 KBUILD_CFLAGS += $(call cc-option,-fno-merge-all-constants)
889 # for gcc -fno-merge-all-constants disables everything, but it is fine
890 # to have actual conforming behavior enabled.
891 KBUILD_CFLAGS += $(call cc-option,-fmerge-constants)
893 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
894 KBUILD_CFLAGS += $(call cc-option,-fno-stack-check,)
896 # conserve stack if available
897 KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
899 # Prohibit date/time macros, which would make the build non-deterministic
900 KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
902 # enforce correct pointer usage
903 KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
905 # Require designated initializers for all marked structures
906 KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
908 # change __FILE__ to the relative path from the srctree
909 KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
911 # ensure -fcf-protection is disabled when using retpoline as it is
912 # incompatible with -mindirect-branch=thunk-extern
913 ifdef CONFIG_RETPOLINE
914 KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none)
917 # use the deterministic mode of AR if available
918 KBUILD_ARFLAGS := $(call ar-option,D)
920 include scripts/Makefile.kasan
921 include scripts/Makefile.extrawarn
922 include scripts/Makefile.ubsan
924 # Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
925 KBUILD_CPPFLAGS += $(KCPPFLAGS)
926 KBUILD_AFLAGS += $(KAFLAGS)
927 KBUILD_CFLAGS += $(KCFLAGS)
929 KBUILD_LDFLAGS_MODULE += --build-id
930 LDFLAGS_vmlinux += --build-id
932 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
933 LDFLAGS_vmlinux += $(call ld-option, -X,)
936 ifeq ($(CONFIG_RELR),y)
937 LDFLAGS_vmlinux += --pack-dyn-relocs=relr
940 # insure the checker run with the right endianness
941 CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
943 # the checker needs the correct machine size
944 CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
946 # Default kernel image to build when no specific target is given.
947 # KBUILD_IMAGE may be overruled on the command line or
948 # set in the environment
949 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
951 export KBUILD_IMAGE ?= vmlinux
954 # INSTALL_PATH specifies where to place the updated kernel and system map
955 # images. Default is /boot, but you can set it to other values
956 export INSTALL_PATH ?= /boot
959 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
960 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
961 # an argument if needed. Otherwise it defaults to the kernel install path
963 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
966 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
967 # relocations required by build roots. This is not defined in the
968 # makefile but the argument can be passed to make if needed.
971 MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
975 # INSTALL_MOD_STRIP, if defined, will cause modules to be
976 # stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
977 # the default option --strip-debug will be used. Otherwise,
978 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
980 ifdef INSTALL_MOD_STRIP
981 ifeq ($(INSTALL_MOD_STRIP),1)
982 mod_strip_cmd = $(STRIP) --strip-debug
984 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
985 endif # INSTALL_MOD_STRIP=1
988 endif # INSTALL_MOD_STRIP
991 # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
992 # after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
993 # or CONFIG_MODULE_COMPRESS_XZ.
995 mod_compress_cmd = true
996 ifdef CONFIG_MODULE_COMPRESS
997 ifdef CONFIG_MODULE_COMPRESS_GZIP
998 mod_compress_cmd = gzip -n -f
999 endif # CONFIG_MODULE_COMPRESS_GZIP
1000 ifdef CONFIG_MODULE_COMPRESS_XZ
1001 mod_compress_cmd = xz -f
1002 endif # CONFIG_MODULE_COMPRESS_XZ
1003 endif # CONFIG_MODULE_COMPRESS
1004 export mod_compress_cmd
1006 ifdef CONFIG_MODULE_SIG_ALL
1007 $(eval $(call config_filename,MODULE_SIG_KEY))
1009 mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
1015 HOST_LIBELF_LIBS = $(shell pkg-config libelf --libs 2>/dev/null || echo -lelf)
1017 ifdef CONFIG_STACK_VALIDATION
1018 has_libelf := $(call try-run,\
1019 echo "int main() {}" | $(HOSTCC) -xc -o /dev/null $(HOST_LIBELF_LIBS) -,1,0)
1020 ifeq ($(has_libelf),1)
1021 objtool_target := tools/objtool FORCE
1023 SKIP_STACK_VALIDATION := 1
1024 export SKIP_STACK_VALIDATION
1030 export MODORDER := $(extmod-prefix)modules.order
1032 ifeq ($(KBUILD_EXTMOD),)
1033 core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
1035 vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
1036 $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1037 $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
1039 vmlinux-alldirs := $(sort $(vmlinux-dirs) Documentation \
1040 $(patsubst %/,%,$(filter %/, $(init-) $(core-) \
1041 $(drivers-) $(net-) $(libs-) $(virt-))))
1043 build-dirs := $(vmlinux-dirs)
1044 clean-dirs := $(vmlinux-alldirs)
1046 init-y := $(patsubst %/, %/built-in.a, $(init-y))
1047 core-y := $(patsubst %/, %/built-in.a, $(core-y))
1048 drivers-y := $(patsubst %/, %/built-in.a, $(drivers-y))
1049 net-y := $(patsubst %/, %/built-in.a, $(net-y))
1050 libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
1051 libs-y2 := $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y)))
1052 virt-y := $(patsubst %/, %/built-in.a, $(virt-y))
1054 # Externally visible symbols (used by link-vmlinux.sh)
1055 export KBUILD_VMLINUX_OBJS := $(head-y) $(init-y) $(core-y) $(libs-y2) \
1056 $(drivers-y) $(net-y) $(virt-y)
1057 export KBUILD_VMLINUX_LIBS := $(libs-y1)
1058 export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
1059 export LDFLAGS_vmlinux
1060 # used by scripts/package/Makefile
1061 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1063 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1065 # Recurse until adjust_autoksyms.sh is satisfied
1066 PHONY += autoksyms_recursive
1067 ifdef CONFIG_TRIM_UNUSED_KSYMS
1068 autoksyms_recursive: descend modules.order
1069 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1070 "$(MAKE) -f $(srctree)/Makefile vmlinux"
1073 # For the kernel to actually contain only the needed exported symbols,
1074 # we have to build modules as well to determine what those symbols are.
1075 # (this can be evaluated only once include/config/auto.conf has been included)
1076 ifdef CONFIG_TRIM_UNUSED_KSYMS
1080 autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1083 $(Q)mkdir -p $(dir $@)
1086 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1088 # Final link of vmlinux with optional arch pass after final link
1089 cmd_link-vmlinux = \
1090 $(CONFIG_SHELL) $< $(LD) $(KBUILD_LDFLAGS) $(LDFLAGS_vmlinux) ; \
1091 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1093 vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1094 +$(call if_changed,link-vmlinux)
1098 # The actual objects are generated when descending,
1099 # make sure no implicit rule kicks in
1100 $(sort $(vmlinux-deps)): descend ;
1102 filechk_kernel.release = \
1103 echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1105 # Store (new) KERNELRELEASE string in include/config/kernel.release
1106 include/config/kernel.release: FORCE
1107 $(call filechk,kernel.release)
1109 # Additional helpers built in scripts/
1110 # Carefully list dependencies so we do not try to build scripts twice
1113 scripts: scripts_basic scripts_dtc
1114 $(Q)$(MAKE) $(build)=$(@)
1116 # Things we need to do before we recursively start building the kernel
1117 # or the modules are listed in "prepare".
1118 # A multi level approach is used. prepareN is processed before prepareN-1.
1119 # archprepare is used in arch Makefiles and when processed asm symlink,
1120 # version.h and scripts_basic is processed / created.
1122 PHONY += prepare archprepare
1124 archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1125 asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h
1127 prepare0: archprepare
1128 $(Q)$(MAKE) $(build)=scripts/mod
1129 $(Q)$(MAKE) $(build)=.
1131 # All the preparing..
1132 prepare: prepare0 prepare-objtool
1134 # Support for using generic headers in asm-generic
1135 asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1137 PHONY += asm-generic uapi-asm-generic
1138 asm-generic: uapi-asm-generic
1139 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1140 generic=include/asm-generic
1142 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1143 generic=include/uapi/asm-generic
1145 PHONY += prepare-objtool
1146 prepare-objtool: $(objtool_target)
1147 ifeq ($(SKIP_STACK_VALIDATION),1)
1148 ifdef CONFIG_UNWINDER_ORC
1149 @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1152 @echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1156 # Generate some files
1157 # ---------------------------------------------------------------------------
1159 # KERNELRELEASE can change from a few different places, meaning version.h
1160 # needs to be updated, so this check is forced on all builds
1163 define filechk_utsrelease.h
1164 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1165 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1168 echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1171 define filechk_version.h
1172 echo \#define LINUX_VERSION_CODE $(shell \
1173 expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
1174 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))'
1178 $(call filechk,version.h)
1179 $(Q)rm -f $(old_version_h)
1181 include/generated/utsrelease.h: include/config/kernel.release FORCE
1182 $(call filechk,utsrelease.h)
1186 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1187 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1189 # ---------------------------------------------------------------------------
1192 #Default location for installed headers
1193 export INSTALL_HDR_PATH = $(objtree)/usr
1195 quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1196 cmd_headers_install = \
1197 mkdir -p $(INSTALL_HDR_PATH); \
1198 rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1199 usr/include $(INSTALL_HDR_PATH)
1201 PHONY += headers_install
1202 headers_install: headers
1203 $(call cmd,headers_install)
1205 PHONY += archheaders archscripts
1207 hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1210 headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1211 $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1212 $(error Headers not exportable for the $(SRCARCH) architecture))
1213 $(Q)$(MAKE) $(hdr-inst)=include/uapi
1214 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1216 PHONY += headers_check
1217 headers_check: headers
1218 $(Q)$(MAKE) $(hdr-inst)=include/uapi HDRCHECK=1
1219 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi HDRCHECK=1
1221 ifdef CONFIG_HEADERS_INSTALL
1225 ifdef CONFIG_HEADERS_CHECK
1229 PHONY += scripts_unifdef
1230 scripts_unifdef: scripts_basic
1231 $(Q)$(MAKE) $(build)=scripts scripts/unifdef
1233 # ---------------------------------------------------------------------------
1238 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1240 PHONY += kselftest-clean
1242 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests clean
1244 PHONY += kselftest-merge
1246 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1247 $(Q)find $(srctree)/tools/testing/selftests -name config | \
1248 xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1249 $(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1251 # ---------------------------------------------------------------------------
1254 ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1255 dtstree := arch/$(SRCARCH)/boot/dts
1260 %.dtb: include/config/kernel.release scripts_dtc
1261 $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1263 PHONY += dtbs dtbs_install dt_binding_check
1264 dtbs dtbs_check: include/config/kernel.release scripts_dtc
1265 $(Q)$(MAKE) $(build)=$(dtstree)
1267 dtbs_check: export CHECK_DTBS=1
1268 dtbs_check: dt_binding_check
1271 $(Q)$(MAKE) $(dtbinst)=$(dtstree)
1273 ifdef CONFIG_OF_EARLY_FLATTREE
1279 PHONY += scripts_dtc
1280 scripts_dtc: scripts_basic
1281 $(Q)$(MAKE) $(build)=scripts/dtc
1283 dt_binding_check: scripts_dtc
1284 $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1286 # ---------------------------------------------------------------------------
1289 ifdef CONFIG_MODULES
1291 # By default, build modules as well
1297 # A module can be listed more than once in obj-m resulting in
1298 # duplicate lines in modules.order files. Those are removed
1299 # using awk while concatenating to the final file.
1302 modules: $(if $(KBUILD_BUILTIN),vmlinux) modules.order modules.builtin
1303 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1304 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh
1306 modules.order: descend
1307 $(Q)$(AWK) '!x[$$0]++' $(addsuffix /$@, $(build-dirs)) > $@
1309 modbuiltin-dirs := $(addprefix _modbuiltin_, $(build-dirs))
1311 modules.builtin: $(modbuiltin-dirs)
1312 $(Q)$(AWK) '!x[$$0]++' $(addsuffix /$@, $(build-dirs)) > $@
1314 PHONY += $(modbuiltin-dirs)
1315 # tristate.conf is not included from this Makefile. Add it as a prerequisite
1316 # here to make it self-healing in case somebody accidentally removes it.
1317 $(modbuiltin-dirs): include/config/tristate.conf
1318 $(Q)$(MAKE) $(modbuiltin)=$(patsubst _modbuiltin_%,%,$@)
1320 # Target to prepare building external modules
1321 PHONY += modules_prepare
1322 modules_prepare: prepare
1324 # Target to install modules
1325 PHONY += modules_install
1326 modules_install: _modinst_ _modinst_post
1330 @rm -rf $(MODLIB)/kernel
1331 @rm -f $(MODLIB)/source
1332 @mkdir -p $(MODLIB)/kernel
1333 @ln -s $(abspath $(srctree)) $(MODLIB)/source
1334 @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
1335 rm -f $(MODLIB)/build ; \
1336 ln -s $(CURDIR) $(MODLIB)/build ; \
1338 @sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1339 @sed 's:^:kernel/:' modules.builtin > $(MODLIB)/modules.builtin
1340 @cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1341 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1343 # This depmod is only for convenience to give the initial
1344 # boot a modules.dep even before / is mounted read-write. However the
1345 # boot script depmod is the master version.
1346 PHONY += _modinst_post
1347 _modinst_post: _modinst_
1350 ifeq ($(CONFIG_MODULE_SIG), y)
1351 PHONY += modules_sign
1353 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1356 else # CONFIG_MODULES
1358 # Modules not configured
1359 # ---------------------------------------------------------------------------
1361 PHONY += modules modules_install
1362 modules modules_install:
1364 @echo >&2 "The present kernel configuration has modules disabled."
1365 @echo >&2 "Type 'make config' and enable loadable module support."
1366 @echo >&2 "Then build a kernel with module support enabled."
1370 endif # CONFIG_MODULES
1373 # Cleaning is done on three levels.
1374 # make clean Delete most generated files
1375 # Leave enough to build external modules
1376 # make mrproper Delete the current configuration, and all generated files
1377 # make distclean Remove editor backup files, patch leftover files and the like
1379 # Directories & files removed with 'make clean'
1380 CLEAN_DIRS += include/ksym
1381 CLEAN_FILES += modules.builtin.modinfo
1383 # Directories & files removed with 'make mrproper'
1384 MRPROPER_DIRS += include/config include/generated \
1385 arch/$(SRCARCH)/include/generated .tmp_objdiff \
1386 debian/ snap/ tar-install/
1387 MRPROPER_FILES += .config .config.old .version \
1389 signing_key.pem signing_key.priv signing_key.x509 \
1390 x509.genkey extra_certificates signing_key.x509.keyid \
1391 signing_key.x509.signer vmlinux-gdb.py \
1394 # Directories & files removed with 'make distclean'
1396 DISTCLEAN_FILES += tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS
1398 # clean - Delete most, but leave enough to build external modules
1400 clean: rm-dirs := $(CLEAN_DIRS)
1401 clean: rm-files := $(CLEAN_FILES)
1403 PHONY += archclean vmlinuxclean
1406 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1407 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1409 clean: archclean vmlinuxclean
1411 # mrproper - Delete all generated files, including .config
1413 mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS))
1414 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1415 mrproper-dirs := $(addprefix _mrproper_,scripts)
1417 PHONY += $(mrproper-dirs) mrproper
1419 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1421 mrproper: clean $(mrproper-dirs)
1427 distclean: rm-dirs := $(wildcard $(DISTCLEAN_DIRS))
1428 distclean: rm-files := $(wildcard $(DISTCLEAN_FILES))
1435 @find $(srctree) $(RCS_FIND_IGNORE) \
1436 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1437 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1438 -o -name 'core' \) \
1439 -type f -print | xargs rm -f
1442 # Packaging of the kernel to various formats
1443 # ---------------------------------------------------------------------------
1446 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1447 %pkg: include/config/kernel.release FORCE
1448 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1450 # Brief documentation of the typical targets used
1451 # ---------------------------------------------------------------------------
1453 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1454 boards := $(sort $(notdir $(boards)))
1455 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1456 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1460 @echo 'Cleaning targets:'
1461 @echo ' clean - Remove most generated files but keep the config and'
1462 @echo ' enough build support to build external modules'
1463 @echo ' mrproper - Remove all generated files + config + various backup files'
1464 @echo ' distclean - mrproper + remove editor backup and patch files'
1466 @echo 'Configuration targets:'
1467 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1469 @echo 'Other generic targets:'
1470 @echo ' all - Build all targets marked with [*]'
1471 @echo '* vmlinux - Build the bare kernel'
1472 @echo '* modules - Build all modules'
1473 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1474 @echo ' dir/ - Build all files in dir and below'
1475 @echo ' dir/file.[ois] - Build specified target only'
1476 @echo ' dir/file.ll - Build the LLVM assembly file'
1477 @echo ' (requires compiler support for LLVM assembly generation)'
1478 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1479 @echo ' (requires a recent binutils and recent build (System.map))'
1480 @echo ' dir/file.ko - Build module including final link'
1481 @echo ' modules_prepare - Set up for building external modules'
1482 @echo ' tags/TAGS - Generate tags file for editors'
1483 @echo ' cscope - Generate cscope index'
1484 @echo ' gtags - Generate GNU GLOBAL index'
1485 @echo ' kernelrelease - Output the release version string (use with make -s)'
1486 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1487 @echo ' image_name - Output the image name (use with make -s)'
1488 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1489 echo ' (default: $(INSTALL_HDR_PATH))'; \
1491 @echo 'Static analysers:'
1492 @echo ' checkstack - Generate a list of stack hogs'
1493 @echo ' namespacecheck - Name space analysis on compiled kernel'
1494 @echo ' versioncheck - Sanity check on version.h usage'
1495 @echo ' includecheck - Check for duplicate included header files'
1496 @echo ' export_report - List the usages of all exported symbols'
1497 @echo ' headers_check - Sanity check on exported headers'
1498 @echo ' headerdep - Detect inclusion cycles in headers'
1499 @echo ' coccicheck - Check with Coccinelle'
1502 @echo ' nsdeps - Generate missing symbol namespace dependencies'
1504 @echo 'Kernel selftest:'
1505 @echo ' kselftest - Build and run kernel selftest (run as root)'
1506 @echo ' Build, install, and boot kernel before'
1507 @echo ' running kselftest on it'
1508 @echo ' kselftest-clean - Remove all generated kselftest files'
1509 @echo ' kselftest-merge - Merge all the config dependencies of kselftest to existing'
1513 echo 'Devicetree:'; \
1514 echo '* dtbs - Build device tree blobs for enabled boards'; \
1515 echo ' dtbs_install - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1516 echo ' dt_binding_check - Validate device tree binding documents'; \
1517 echo ' dtbs_check - Validate device tree source files';\
1520 @echo 'Userspace tools targets:'
1521 @echo ' use "make tools/help"'
1522 @echo ' or "cd tools; make help"'
1524 @echo 'Kernel packaging:'
1525 @$(MAKE) -f $(srctree)/scripts/Makefile.package help
1527 @echo 'Documentation targets:'
1528 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1530 @echo 'Architecture specific targets ($(SRCARCH)):'
1531 @$(if $(archhelp),$(archhelp),\
1532 echo ' No architecture specific help defined for $(SRCARCH)')
1535 $(foreach b, $(boards), \
1536 printf " %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1538 @$(if $(board-dirs), \
1539 $(foreach b, $(board-dirs), \
1540 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1541 printf " %-16s - Show all of the above\\n" help-boards; \
1544 @echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1545 @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
1546 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1547 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK (sparse by default)'
1548 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1549 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1550 @echo ' make W=n [targets] Enable extra build checks, n=1,2,3 where'
1551 @echo ' 1: warnings which may be relevant and do not occur too often'
1552 @echo ' 2: warnings which occur quite often but may still be relevant'
1553 @echo ' 3: more obscure warnings, can most likely be ignored'
1554 @echo ' Multiple levels can be combined with W=12 or W=123'
1556 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1557 @echo 'For further info see the ./README file'
1560 help-board-dirs := $(addprefix help-,$(board-dirs))
1562 help-boards: $(help-board-dirs)
1564 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1566 $(help-board-dirs): help-%:
1567 @echo 'Architecture specific targets ($(SRCARCH) $*):'
1568 @$(if $(boards-per-dir), \
1569 $(foreach b, $(boards-per-dir), \
1570 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1574 # Documentation targets
1575 # ---------------------------------------------------------------------------
1576 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1577 linkcheckdocs dochelp refcheckdocs
1578 PHONY += $(DOC_TARGETS)
1580 $(Q)$(MAKE) $(build)=Documentation $@
1583 # ---------------------------------------------------------------------------
1585 PHONY += scripts_gdb
1586 scripts_gdb: prepare0
1587 $(Q)$(MAKE) $(build)=scripts/gdb
1588 $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1590 ifdef CONFIG_GDB_SCRIPTS
1594 else # KBUILD_EXTMOD
1597 # External module support.
1598 # When building external modules the kernel used as basis is considered
1599 # read-only, and no consistency checks are made and the make
1600 # system is not used on the basis kernel. If updates are required
1601 # in the basis kernel ordinary make commands (without M=...) must
1604 # The following are the only valid targets when building external
1606 # make M=dir clean Delete all automatically generated files
1607 # make M=dir modules Make all modules in specified dir
1608 # make M=dir Same as 'make M=dir modules'
1609 # make M=dir modules_install
1610 # Install the modules built in the module directory
1611 # Assumes install directory is already created
1613 # We are always building modules
1616 PHONY += $(objtree)/Module.symvers
1617 $(objtree)/Module.symvers:
1618 @test -e $(objtree)/Module.symvers || ( \
1620 echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1621 echo " is missing; modules will have no dependencies and modversions."; \
1624 build-dirs := $(KBUILD_EXTMOD)
1626 modules: descend $(objtree)/Module.symvers
1627 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1629 PHONY += modules_install
1630 modules_install: _emodinst_ _emodinst_post
1632 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1635 $(Q)mkdir -p $(MODLIB)/$(install-dir)
1636 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1638 PHONY += _emodinst_post
1639 _emodinst_post: _emodinst_
1642 clean-dirs := $(KBUILD_EXTMOD)
1643 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1647 @echo >&2 '"$(MAKE) /" is no longer supported. Please use "$(MAKE) ./" instead.'
1651 @echo ' Building external modules.'
1652 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1654 @echo ' modules - default target, build the module(s)'
1655 @echo ' modules_install - install the module'
1656 @echo ' clean - remove generated files in module directory only'
1660 endif # KBUILD_EXTMOD
1662 # Handle descending into subdirectories listed in $(build-dirs)
1663 # Preset locale variables to speed up the build process. Limit locale
1664 # tweaks to this spot to avoid wrong language settings when running
1665 # make menuconfig etc.
1666 # Error messages still appears in the original language
1667 PHONY += descend $(build-dirs)
1668 descend: $(build-dirs)
1669 $(build-dirs): prepare
1670 $(Q)$(MAKE) $(build)=$@ single-build=$(single-build) need-builtin=1 need-modorder=1
1672 clean-dirs := $(addprefix _clean_, $(clean-dirs))
1673 PHONY += $(clean-dirs) clean
1675 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1677 clean: $(clean-dirs)
1680 @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1681 \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1683 -o -name '*.dtb' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1684 -o -name '*.dwo' -o -name '*.lst' \
1685 -o -name '*.su' -o -name '*.mod' -o -name '*.ns_deps' \
1686 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1687 -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1688 -o -name '*.asn1.[ch]' \
1689 -o -name '*.symtypes' -o -name 'modules.order' \
1690 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1691 -o -name '*.c.[012]*.*' \
1693 -o -name '*.gcno' \) -type f -print | xargs rm -f
1695 # Generate tags for editors
1696 # ---------------------------------------------------------------------------
1697 quiet_cmd_tags = GEN $@
1698 cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1700 tags TAGS cscope gtags: FORCE
1703 # Script to generate missing namespace dependencies
1704 # ---------------------------------------------------------------------------
1709 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost nsdeps
1710 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1712 # Scripts to check various things for consistency
1713 # ---------------------------------------------------------------------------
1715 PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1718 find $(srctree)/* $(RCS_FIND_IGNORE) \
1719 -name '*.[hcS]' -type f -print | sort \
1720 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1723 find $(srctree)/* $(RCS_FIND_IGNORE) \
1724 -name '*.[hcS]' -type f -print | sort \
1725 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1728 $(Q)$(BASH) $(srctree)/scripts/$@
1731 $(PERL) $(srctree)/scripts/namespace.pl
1734 $(PERL) $(srctree)/scripts/export_report.pl
1736 PHONY += checkstack kernelrelease kernelversion image_name
1738 # UML needs a little special treatment here. It wants to use the host
1739 # toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
1740 # else wants $(ARCH), including people doing cross-builds, which means
1741 # that $(SUBARCH) doesn't work here.
1743 CHECKSTACK_ARCH := $(SUBARCH)
1745 CHECKSTACK_ARCH := $(ARCH)
1748 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1749 $(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1752 @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1755 @echo $(KERNELVERSION)
1758 @echo $(KBUILD_IMAGE)
1760 # Clear a bunch of variables before executing the submake
1762 ifeq ($(quiet),silent_)
1767 $(Q)mkdir -p $(objtree)/tools
1768 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1771 $(Q)mkdir -p $(objtree)/tools
1772 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1775 # ---------------------------------------------------------------------------
1776 # To build individual files in subdirectories, you can do like this:
1778 # make foo/bar/baz.s
1780 # The supported suffixes for single-target are listed in 'single-targets'
1782 # To build only under specific subdirectories, you can do like this:
1788 single-all := $(filter $(single-targets), $(MAKECMDGOALS))
1790 # .ko is special because modpost is needed
1791 single-ko := $(sort $(filter %.ko, $(single-all)))
1792 single-no-ko := $(sort $(patsubst %.ko,%.mod, $(single-all)))
1794 $(single-ko): single_modpost
1796 $(single-no-ko): descend
1799 ifeq ($(KBUILD_EXTMOD),)
1800 # For the single build of in-tree modules, use a temporary file to avoid
1801 # the situation of modules_install installing an invalid modules.order.
1802 MODORDER := .modules.tmp
1805 PHONY += single_modpost
1806 single_modpost: $(single-no-ko)
1807 $(Q){ $(foreach m, $(single-ko), echo $(extmod-prefix)$m;) } > $(MODORDER)
1808 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1812 export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod-prefix), $(single-no-ko))
1814 single-build = $(if $(filter-out $@/, $(single-no-ko)),1)
1818 # FIXME Should go into a make.lib or something
1819 # ===========================================================================
1821 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs)))
1822 cmd_rmdirs = rm -rf $(rm-dirs)
1824 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
1825 cmd_rmfiles = rm -f $(rm-files)
1827 # Run depmod only if we have System.map and depmod is executable
1828 quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
1829 cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1832 # read saved command lines for existing targets
1833 existing-targets := $(wildcard $(sort $(targets)))
1835 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1837 endif # config-targets
1839 endif # need-sub-make
1844 # Declare the contents of the PHONY variable as phony. We keep that
1845 # information in a variable so we can use it in if_changed and friends.