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
407 CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
408 else if [ -x /bin/bash ]; then echo /bin/bash; \
409 else echo sh; fi ; fi)
411 HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
412 HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
413 HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
417 KBUILD_HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 \
418 -fomit-frame-pointer -std=gnu89 $(HOST_LFS_CFLAGS) \
420 KBUILD_HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
421 KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
422 KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
424 # Make variables (CC, etc...)
425 AS = $(CROSS_COMPILE)as
426 LD = $(CROSS_COMPILE)ld
427 CC = $(CROSS_COMPILE)gcc
429 AR = $(CROSS_COMPILE)ar
430 NM = $(CROSS_COMPILE)nm
431 STRIP = $(CROSS_COMPILE)strip
432 OBJCOPY = $(CROSS_COMPILE)objcopy
433 OBJDUMP = $(CROSS_COMPILE)objdump
434 OBJSIZE = $(CROSS_COMPILE)size
439 INSTALLKERNEL := installkernel
440 DEPMOD = /sbin/depmod
447 CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
448 -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
457 # Use USERINCLUDE when you must reference the UAPI directories only.
459 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
460 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
461 -I$(srctree)/include/uapi \
462 -I$(objtree)/include/generated/uapi \
463 -include $(srctree)/include/linux/kconfig.h
465 # Use LINUXINCLUDE when you must reference the include/ directory.
466 # Needed to be compatible with the O= option
468 -I$(srctree)/arch/$(SRCARCH)/include \
469 -I$(objtree)/arch/$(SRCARCH)/include/generated \
470 $(if $(building_out_of_srctree),-I$(srctree)/include) \
471 -I$(objtree)/include \
474 KBUILD_AFLAGS := -D__ASSEMBLY__ -fno-PIE
475 KBUILD_CFLAGS := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
476 -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
477 -Werror=implicit-function-declaration -Werror=implicit-int \
478 -Wno-format-security \
480 KBUILD_CPPFLAGS := -D__KERNEL__
481 KBUILD_AFLAGS_KERNEL :=
482 KBUILD_CFLAGS_KERNEL :=
483 KBUILD_AFLAGS_MODULE := -DMODULE
484 KBUILD_CFLAGS_MODULE := -DMODULE
485 KBUILD_LDFLAGS_MODULE :=
486 export KBUILD_LDS_MODULE := $(srctree)/scripts/module-common.lds
488 GCC_PLUGINS_CFLAGS :=
491 export ARCH SRCARCH CONFIG_SHELL HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE AS LD CC
492 export CPP AR NM STRIP OBJCOPY OBJDUMP OBJSIZE PAHOLE LEX YACC AWK INSTALLKERNEL
493 export PERL PYTHON PYTHON2 PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
494 export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
496 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
497 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
498 export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN
499 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
500 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
501 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
502 export KBUILD_ARFLAGS
504 # Files to ignore in find ... statements
506 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
507 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
509 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
510 --exclude CVS --exclude .pc --exclude .hg --exclude .git
512 # ===========================================================================
513 # Rules shared between *config targets and build targets
515 # Basic helpers built in scripts/basic/
516 PHONY += scripts_basic
518 $(Q)$(MAKE) $(build)=scripts/basic
519 $(Q)rm -f .tmp_quiet_recordmcount
521 PHONY += outputmakefile
522 # Before starting out-of-tree build, make sure the source tree is clean.
523 # outputmakefile generates a Makefile in the output directory, if using a
524 # separate output directory. This allows convenient use of make in the
526 # At the same time when output Makefile generated, generate .gitignore to
527 # ignore whole output directory
529 ifdef building_out_of_srctree
530 $(Q)if [ -f $(srctree)/.config -o \
531 -d $(srctree)/include/config -o \
532 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
534 echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
535 echo >&2 "*** in $(abs_srctree)";\
539 $(Q)ln -fsn $(srctree) source
540 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
541 $(Q)test -e .gitignore || \
542 { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
545 ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
546 ifneq ($(CROSS_COMPILE),)
547 CLANG_FLAGS += --target=$(notdir $(CROSS_COMPILE:%-=%))
548 GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
549 CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)
550 GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..)
552 ifneq ($(GCC_TOOLCHAIN),)
553 CLANG_FLAGS += --gcc-toolchain=$(GCC_TOOLCHAIN)
555 ifeq ($(shell $(AS) --version 2>&1 | head -n 1 | grep clang),)
556 CLANG_FLAGS += -no-integrated-as
558 CLANG_FLAGS += -Werror=unknown-warning-option
559 KBUILD_CFLAGS += $(CLANG_FLAGS)
560 KBUILD_AFLAGS += $(CLANG_FLAGS)
564 # The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
565 # Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
566 # CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
567 # and from include/config/auto.conf.cmd to detect the compiler upgrade.
568 CC_VERSION_TEXT = $(shell $(CC) --version 2>/dev/null | head -n 1)
571 # ===========================================================================
572 # *config targets only - make sure prerequisites are updated, and descend
573 # in scripts/kconfig to make the *config target
575 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
576 # KBUILD_DEFCONFIG may point out an alternative default configuration
577 # used for 'make defconfig'
578 include arch/$(SRCARCH)/Makefile
579 export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
581 config: outputmakefile scripts_basic FORCE
582 $(Q)$(MAKE) $(build)=scripts/kconfig $@
584 %config: outputmakefile scripts_basic FORCE
585 $(Q)$(MAKE) $(build)=scripts/kconfig $@
588 # ===========================================================================
589 # Build targets only - this includes vmlinux, arch specific targets, clean
590 # targets and others. In general all targets except *config targets.
592 # If building an external module we do not care about the all: rule
593 # but instead _all depend on modules
595 ifeq ($(KBUILD_EXTMOD),)
601 # Decide whether to build built-in, modular, or both.
602 # Normally, just do built-in.
607 # If we have only "make modules", don't compile built-in objects.
608 # When we're building modules with modversions, we need to consider
609 # the built-in objects during the descend as well, in order to
610 # make sure the checksums are up to date before we record them.
612 ifeq ($(MAKECMDGOALS),modules)
613 KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
616 # If we have "make <whatever> modules", compile modules
617 # in addition to whatever we do anyway.
618 # Just "make" or "make all" shall build modules as well
620 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
624 ifeq ($(MAKECMDGOALS),)
628 export KBUILD_MODULES KBUILD_BUILTIN
631 include include/config/auto.conf
634 ifeq ($(KBUILD_EXTMOD),)
635 # Objects we will link into vmlinux / subdirs we need to visit
637 drivers-y := drivers/ sound/
638 drivers-$(CONFIG_SAMPLES) += samples/
639 drivers-$(CONFIG_KERNEL_HEADER_TEST) += include/
644 endif # KBUILD_EXTMOD
646 # The all: target is the default when no target is given on the
648 # This allow a user to issue only 'make' to build a kernel including modules
649 # Defaults to vmlinux, but the arch makefile usually adds further targets
652 CFLAGS_GCOV := -fprofile-arcs -ftest-coverage \
653 $(call cc-option,-fno-tree-loop-im) \
654 $(call cc-disable-warning,maybe-uninitialized,)
657 # The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
658 ifdef CONFIG_FUNCTION_TRACER
659 CC_FLAGS_FTRACE := -pg
662 RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
663 RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
664 RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
665 RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
666 RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
667 RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
668 export RETPOLINE_CFLAGS
669 export RETPOLINE_VDSO_CFLAGS
671 # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
672 # values of the respective KBUILD_* variables
676 include arch/$(SRCARCH)/Makefile
679 ifdef may-sync-config
680 # Read in dependencies to all Kconfig* files, make sure to run syncconfig if
681 # changes are detected. This should be included after arch/$(SRCARCH)/Makefile
682 # because some architectures define CROSS_COMPILE there.
683 include include/config/auto.conf.cmd
687 @echo >&2 '*** Configuration file "$@" not found!'
689 @echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
690 @echo >&2 '*** "make menuconfig" or "make xconfig").'
694 # The actual configuration files used during the build are stored in
695 # include/generated/ and include/config/. Update them if .config is newer than
696 # include/config/auto.conf (which mirrors .config).
698 # This exploits the 'multi-target pattern rule' trick.
699 # The syncconfig should be executed only once to make all the targets.
700 %/auto.conf %/auto.conf.cmd %/tristate.conf: $(KCONFIG_CONFIG)
701 $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
702 else # !may-sync-config
703 # External modules and some install targets need include/generated/autoconf.h
704 # and include/config/auto.conf but do not care if they are up-to-date.
705 # Use auto.conf to trigger the test
706 PHONY += include/config/auto.conf
708 include/config/auto.conf:
709 $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
711 echo >&2 " ERROR: Kernel configuration is invalid."; \
712 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
713 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
717 endif # may-sync-config
720 KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
721 KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
722 KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
723 KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
724 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
726 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
732 ifdef CONFIG_CC_DISABLE_WARN_MAYBE_UNINITIALIZED
733 KBUILD_CFLAGS += -Wno-maybe-uninitialized
736 # Tell gcc to never replace conditional load with a non-conditional one
737 KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
739 include scripts/Makefile.kcov
740 include scripts/Makefile.gcc-plugins
742 ifdef CONFIG_READABLE_ASM
743 # Disable optimizations that make assembler listings hard to read.
744 # reorder blocks reorders the control in the function
745 # ipa clone creates specialized cloned functions
746 # partial inlining inlines only parts of functions
747 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
748 $(call cc-option,-fno-ipa-cp-clone,) \
749 $(call cc-option,-fno-partial-inlining)
752 ifneq ($(CONFIG_FRAME_WARN),0)
753 KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
756 stackp-flags-$(CONFIG_CC_HAS_STACKPROTECTOR_NONE) := -fno-stack-protector
757 stackp-flags-$(CONFIG_STACKPROTECTOR) := -fstack-protector
758 stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong
760 KBUILD_CFLAGS += $(stackp-flags-y)
762 ifdef CONFIG_CC_IS_CLANG
763 KBUILD_CPPFLAGS += -Qunused-arguments
764 KBUILD_CFLAGS += -Wno-format-invalid-specifier
765 KBUILD_CFLAGS += -Wno-gnu
766 # Quiet clang warning: comparison of unsigned expression < 0 is always false
767 KBUILD_CFLAGS += -Wno-tautological-compare
768 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
769 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
770 # See modpost pattern 2
771 KBUILD_CFLAGS += -mno-global-merge
774 # These warnings generated too much noise in a regular build.
775 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
776 KBUILD_CFLAGS += -Wno-unused-but-set-variable
778 # Warn about unmarked fall-throughs in switch statement.
779 # Disabled for clang while comment to attribute conversion happens and
780 # https://github.com/ClangBuiltLinux/linux/issues/636 is discussed.
781 KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough,)
784 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
785 ifdef CONFIG_FRAME_POINTER
786 KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
788 # Some targets (ARM with Thumb2, for example), can't be built with frame
789 # pointers. For those, we don't have FUNCTION_TRACER automatically
790 # select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
791 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
792 # -fomit-frame-pointer with FUNCTION_TRACER.
793 ifndef CONFIG_FUNCTION_TRACER
794 KBUILD_CFLAGS += -fomit-frame-pointer
798 # Initialize all stack variables with a pattern, if desired.
799 ifdef CONFIG_INIT_STACK_ALL
800 KBUILD_CFLAGS += -ftrivial-auto-var-init=pattern
803 DEBUG_CFLAGS := $(call cc-option, -fno-var-tracking-assignments)
805 ifdef CONFIG_DEBUG_INFO
806 ifdef CONFIG_DEBUG_INFO_SPLIT
807 DEBUG_CFLAGS += -gsplit-dwarf
811 KBUILD_AFLAGS += -Wa,-gdwarf-2
813 ifdef CONFIG_DEBUG_INFO_DWARF4
814 DEBUG_CFLAGS += -gdwarf-4
817 ifdef CONFIG_DEBUG_INFO_REDUCED
818 DEBUG_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
819 $(call cc-option,-fno-var-tracking)
822 KBUILD_CFLAGS += $(DEBUG_CFLAGS)
825 ifdef CONFIG_FUNCTION_TRACER
826 ifdef CONFIG_FTRACE_MCOUNT_RECORD
827 # gcc 5 supports generating the mcount tables directly
828 ifeq ($(call cc-option-yn,-mrecord-mcount),y)
829 CC_FLAGS_FTRACE += -mrecord-mcount
830 export CC_USING_RECORD_MCOUNT := 1
832 ifdef CONFIG_HAVE_NOP_MCOUNT
833 ifeq ($(call cc-option-yn, -mnop-mcount),y)
834 CC_FLAGS_FTRACE += -mnop-mcount
835 CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
839 ifdef CONFIG_HAVE_FENTRY
840 ifeq ($(call cc-option-yn, -mfentry),y)
841 CC_FLAGS_FTRACE += -mfentry
842 CC_FLAGS_USING += -DCC_USING_FENTRY
845 export CC_FLAGS_FTRACE
846 KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
847 KBUILD_AFLAGS += $(CC_FLAGS_USING)
848 ifdef CONFIG_DYNAMIC_FTRACE
849 ifdef CONFIG_HAVE_C_RECORDMCOUNT
850 BUILD_C_RECORDMCOUNT := y
851 export BUILD_C_RECORDMCOUNT
856 # We trigger additional mismatches with less inlining
857 ifdef CONFIG_DEBUG_SECTION_MISMATCH
858 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
861 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
862 KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
863 LDFLAGS_vmlinux += --gc-sections
866 ifdef CONFIG_LIVEPATCH
867 KBUILD_CFLAGS += $(call cc-option, -flive-patching=inline-clone)
870 # arch Makefile may override CC so keep this after arch Makefile is included
871 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
873 # warn about C99 declaration after statement
874 KBUILD_CFLAGS += -Wdeclaration-after-statement
876 # Variable Length Arrays (VLAs) should not be used anywhere in the kernel
877 KBUILD_CFLAGS += -Wvla
879 # disable pointer signed / unsigned warnings in gcc 4.0
880 KBUILD_CFLAGS += -Wno-pointer-sign
882 # disable stringop warnings in gcc 8+
883 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
885 # disable invalid "can't wrap" optimizations for signed / pointers
886 KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
888 # clang sets -fmerge-all-constants by default as optimization, but this
889 # is non-conforming behavior for C and in fact breaks the kernel, so we
890 # need to disable it here generally.
891 KBUILD_CFLAGS += $(call cc-option,-fno-merge-all-constants)
893 # for gcc -fno-merge-all-constants disables everything, but it is fine
894 # to have actual conforming behavior enabled.
895 KBUILD_CFLAGS += $(call cc-option,-fmerge-constants)
897 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
898 KBUILD_CFLAGS += $(call cc-option,-fno-stack-check,)
900 # conserve stack if available
901 KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
903 # Prohibit date/time macros, which would make the build non-deterministic
904 KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
906 # enforce correct pointer usage
907 KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
909 # Require designated initializers for all marked structures
910 KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
912 # change __FILE__ to the relative path from the srctree
913 KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
915 # ensure -fcf-protection is disabled when using retpoline as it is
916 # incompatible with -mindirect-branch=thunk-extern
917 ifdef CONFIG_RETPOLINE
918 KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none)
921 # use the deterministic mode of AR if available
922 KBUILD_ARFLAGS := $(call ar-option,D)
924 include scripts/Makefile.kasan
925 include scripts/Makefile.extrawarn
926 include scripts/Makefile.ubsan
928 # Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
930 KBUILD_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS)
931 KBUILD_AFLAGS += $(ARCH_AFLAGS) $(KAFLAGS)
932 KBUILD_CFLAGS += $(ARCH_CFLAGS) $(KCFLAGS)
934 KBUILD_LDFLAGS_MODULE += --build-id
935 LDFLAGS_vmlinux += --build-id
937 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
938 LDFLAGS_vmlinux += $(call ld-option, -X,)
941 # insure the checker run with the right endianness
942 CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
944 # the checker needs the correct machine size
945 CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
947 # Default kernel image to build when no specific target is given.
948 # KBUILD_IMAGE may be overruled on the command line or
949 # set in the environment
950 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
952 export KBUILD_IMAGE ?= vmlinux
955 # INSTALL_PATH specifies where to place the updated kernel and system map
956 # images. Default is /boot, but you can set it to other values
957 export INSTALL_PATH ?= /boot
960 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
961 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
962 # an argument if needed. Otherwise it defaults to the kernel install path
964 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
967 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
968 # relocations required by build roots. This is not defined in the
969 # makefile but the argument can be passed to make if needed.
972 MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
976 # INSTALL_MOD_STRIP, if defined, will cause modules to be
977 # stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
978 # the default option --strip-debug will be used. Otherwise,
979 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
981 ifdef INSTALL_MOD_STRIP
982 ifeq ($(INSTALL_MOD_STRIP),1)
983 mod_strip_cmd = $(STRIP) --strip-debug
985 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
986 endif # INSTALL_MOD_STRIP=1
989 endif # INSTALL_MOD_STRIP
992 # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
993 # after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
994 # or CONFIG_MODULE_COMPRESS_XZ.
996 mod_compress_cmd = true
997 ifdef CONFIG_MODULE_COMPRESS
998 ifdef CONFIG_MODULE_COMPRESS_GZIP
999 mod_compress_cmd = gzip -n -f
1000 endif # CONFIG_MODULE_COMPRESS_GZIP
1001 ifdef CONFIG_MODULE_COMPRESS_XZ
1002 mod_compress_cmd = xz -f
1003 endif # CONFIG_MODULE_COMPRESS_XZ
1004 endif # CONFIG_MODULE_COMPRESS
1005 export mod_compress_cmd
1007 ifdef CONFIG_MODULE_SIG_ALL
1008 $(eval $(call config_filename,MODULE_SIG_KEY))
1010 mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
1016 HOST_LIBELF_LIBS = $(shell pkg-config libelf --libs 2>/dev/null || echo -lelf)
1018 ifdef CONFIG_STACK_VALIDATION
1019 has_libelf := $(call try-run,\
1020 echo "int main() {}" | $(HOSTCC) -xc -o /dev/null $(HOST_LIBELF_LIBS) -,1,0)
1021 ifeq ($(has_libelf),1)
1022 objtool_target := tools/objtool FORCE
1024 SKIP_STACK_VALIDATION := 1
1025 export SKIP_STACK_VALIDATION
1031 export MODORDER := $(extmod-prefix)modules.order
1033 ifeq ($(KBUILD_EXTMOD),)
1034 core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
1036 vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
1037 $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1038 $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
1040 vmlinux-alldirs := $(sort $(vmlinux-dirs) Documentation \
1041 $(patsubst %/,%,$(filter %/, $(init-) $(core-) \
1042 $(drivers-) $(net-) $(libs-) $(virt-))))
1044 build-dirs := $(vmlinux-dirs)
1045 clean-dirs := $(vmlinux-alldirs)
1047 init-y := $(patsubst %/, %/built-in.a, $(init-y))
1048 core-y := $(patsubst %/, %/built-in.a, $(core-y))
1049 drivers-y := $(patsubst %/, %/built-in.a, $(drivers-y))
1050 net-y := $(patsubst %/, %/built-in.a, $(net-y))
1051 libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
1052 libs-y2 := $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y)))
1053 virt-y := $(patsubst %/, %/built-in.a, $(virt-y))
1055 # Externally visible symbols (used by link-vmlinux.sh)
1056 export KBUILD_VMLINUX_OBJS := $(head-y) $(init-y) $(core-y) $(libs-y2) \
1057 $(drivers-y) $(net-y) $(virt-y)
1058 export KBUILD_VMLINUX_LIBS := $(libs-y1)
1059 export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
1060 export LDFLAGS_vmlinux
1061 # used by scripts/package/Makefile
1062 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1064 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1066 # Recurse until adjust_autoksyms.sh is satisfied
1067 PHONY += autoksyms_recursive
1068 ifdef CONFIG_TRIM_UNUSED_KSYMS
1069 autoksyms_recursive: descend modules.order
1070 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1071 "$(MAKE) -f $(srctree)/Makefile vmlinux"
1074 # For the kernel to actually contain only the needed exported symbols,
1075 # we have to build modules as well to determine what those symbols are.
1076 # (this can be evaluated only once include/config/auto.conf has been included)
1077 ifdef CONFIG_TRIM_UNUSED_KSYMS
1081 autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1084 $(Q)mkdir -p $(dir $@)
1087 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1089 # Final link of vmlinux with optional arch pass after final link
1090 cmd_link-vmlinux = \
1091 $(CONFIG_SHELL) $< $(LD) $(KBUILD_LDFLAGS) $(LDFLAGS_vmlinux) ; \
1092 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1094 vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1095 +$(call if_changed,link-vmlinux)
1099 # The actual objects are generated when descending,
1100 # make sure no implicit rule kicks in
1101 $(sort $(vmlinux-deps)): descend ;
1103 filechk_kernel.release = \
1104 echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1106 # Store (new) KERNELRELEASE string in include/config/kernel.release
1107 include/config/kernel.release: FORCE
1108 $(call filechk,kernel.release)
1110 # Additional helpers built in scripts/
1111 # Carefully list dependencies so we do not try to build scripts twice
1114 scripts: scripts_basic scripts_dtc
1115 $(Q)$(MAKE) $(build)=$(@)
1117 # Things we need to do before we recursively start building the kernel
1118 # or the modules are listed in "prepare".
1119 # A multi level approach is used. prepareN is processed before prepareN-1.
1120 # archprepare is used in arch Makefiles and when processed asm symlink,
1121 # version.h and scripts_basic is processed / created.
1123 PHONY += prepare archprepare
1125 archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1126 asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h
1128 prepare0: archprepare
1129 $(Q)$(MAKE) $(build)=scripts/mod
1130 $(Q)$(MAKE) $(build)=.
1132 # All the preparing..
1133 prepare: prepare0 prepare-objtool
1135 # Support for using generic headers in asm-generic
1136 asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1138 PHONY += asm-generic uapi-asm-generic
1139 asm-generic: uapi-asm-generic
1140 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1141 generic=include/asm-generic
1143 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1144 generic=include/uapi/asm-generic
1146 PHONY += prepare-objtool
1147 prepare-objtool: $(objtool_target)
1148 ifeq ($(SKIP_STACK_VALIDATION),1)
1149 ifdef CONFIG_UNWINDER_ORC
1150 @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1153 @echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1157 # Generate some files
1158 # ---------------------------------------------------------------------------
1160 # KERNELRELEASE can change from a few different places, meaning version.h
1161 # needs to be updated, so this check is forced on all builds
1164 define filechk_utsrelease.h
1165 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1166 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1169 echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1172 define filechk_version.h
1173 echo \#define LINUX_VERSION_CODE $(shell \
1174 expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
1175 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))'
1179 $(call filechk,version.h)
1180 $(Q)rm -f $(old_version_h)
1182 include/generated/utsrelease.h: include/config/kernel.release FORCE
1183 $(call filechk,utsrelease.h)
1187 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1188 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1190 # ---------------------------------------------------------------------------
1193 #Default location for installed headers
1194 export INSTALL_HDR_PATH = $(objtree)/usr
1196 quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1197 cmd_headers_install = \
1198 mkdir -p $(INSTALL_HDR_PATH); \
1199 rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1200 usr/include $(INSTALL_HDR_PATH)
1202 PHONY += headers_install
1203 headers_install: headers
1204 $(call cmd,headers_install)
1206 PHONY += archheaders archscripts
1208 hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1211 headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1212 $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1213 $(error Headers not exportable for the $(SRCARCH) architecture))
1214 $(Q)$(MAKE) $(hdr-inst)=include/uapi
1215 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1217 PHONY += headers_check
1218 headers_check: headers
1219 $(Q)$(MAKE) $(hdr-inst)=include/uapi HDRCHECK=1
1220 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi HDRCHECK=1
1222 ifdef CONFIG_HEADERS_INSTALL
1226 ifdef CONFIG_HEADERS_CHECK
1230 PHONY += scripts_unifdef
1231 scripts_unifdef: scripts_basic
1232 $(Q)$(MAKE) $(build)=scripts scripts/unifdef
1234 # ---------------------------------------------------------------------------
1239 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1241 PHONY += kselftest-clean
1243 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests clean
1245 PHONY += kselftest-merge
1247 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1248 $(Q)find $(srctree)/tools/testing/selftests -name config | \
1249 xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1250 $(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1252 # ---------------------------------------------------------------------------
1255 ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1256 dtstree := arch/$(SRCARCH)/boot/dts
1261 %.dtb: include/config/kernel.release scripts_dtc
1262 $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1264 PHONY += dtbs dtbs_install dt_binding_check
1265 dtbs dtbs_check: include/config/kernel.release scripts_dtc
1266 $(Q)$(MAKE) $(build)=$(dtstree)
1268 dtbs_check: export CHECK_DTBS=1
1269 dtbs_check: dt_binding_check
1272 $(Q)$(MAKE) $(dtbinst)=$(dtstree)
1274 ifdef CONFIG_OF_EARLY_FLATTREE
1280 PHONY += scripts_dtc
1281 scripts_dtc: scripts_basic
1282 $(Q)$(MAKE) $(build)=scripts/dtc
1284 dt_binding_check: scripts_dtc
1285 $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1287 # ---------------------------------------------------------------------------
1290 ifdef CONFIG_MODULES
1292 # By default, build modules as well
1298 # A module can be listed more than once in obj-m resulting in
1299 # duplicate lines in modules.order files. Those are removed
1300 # using awk while concatenating to the final file.
1303 modules: $(if $(KBUILD_BUILTIN),vmlinux) modules.order modules.builtin
1304 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1305 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh
1307 modules.order: descend
1308 $(Q)$(AWK) '!x[$$0]++' $(addsuffix /$@, $(build-dirs)) > $@
1310 modbuiltin-dirs := $(addprefix _modbuiltin_, $(build-dirs))
1312 modules.builtin: $(modbuiltin-dirs)
1313 $(Q)$(AWK) '!x[$$0]++' $(addsuffix /$@, $(build-dirs)) > $@
1315 PHONY += $(modbuiltin-dirs)
1316 # tristate.conf is not included from this Makefile. Add it as a prerequisite
1317 # here to make it self-healing in case somebody accidentally removes it.
1318 $(modbuiltin-dirs): include/config/tristate.conf
1319 $(Q)$(MAKE) $(modbuiltin)=$(patsubst _modbuiltin_%,%,$@)
1321 # Target to prepare building external modules
1322 PHONY += modules_prepare
1323 modules_prepare: prepare
1325 # Target to install modules
1326 PHONY += modules_install
1327 modules_install: _modinst_ _modinst_post
1331 @rm -rf $(MODLIB)/kernel
1332 @rm -f $(MODLIB)/source
1333 @mkdir -p $(MODLIB)/kernel
1334 @ln -s $(abspath $(srctree)) $(MODLIB)/source
1335 @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
1336 rm -f $(MODLIB)/build ; \
1337 ln -s $(CURDIR) $(MODLIB)/build ; \
1339 @sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1340 @sed 's:^:kernel/:' modules.builtin > $(MODLIB)/modules.builtin
1341 @cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1342 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1344 # This depmod is only for convenience to give the initial
1345 # boot a modules.dep even before / is mounted read-write. However the
1346 # boot script depmod is the master version.
1347 PHONY += _modinst_post
1348 _modinst_post: _modinst_
1351 ifeq ($(CONFIG_MODULE_SIG), y)
1352 PHONY += modules_sign
1354 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1357 else # CONFIG_MODULES
1359 # Modules not configured
1360 # ---------------------------------------------------------------------------
1362 PHONY += modules modules_install
1363 modules modules_install:
1365 @echo >&2 "The present kernel configuration has modules disabled."
1366 @echo >&2 "Type 'make config' and enable loadable module support."
1367 @echo >&2 "Then build a kernel with module support enabled."
1371 endif # CONFIG_MODULES
1374 # Cleaning is done on three levels.
1375 # make clean Delete most generated files
1376 # Leave enough to build external modules
1377 # make mrproper Delete the current configuration, and all generated files
1378 # make distclean Remove editor backup files, patch leftover files and the like
1380 # Directories & files removed with 'make clean'
1381 CLEAN_DIRS += include/ksym
1382 CLEAN_FILES += modules.builtin.modinfo
1384 # Directories & files removed with 'make mrproper'
1385 MRPROPER_DIRS += include/config include/generated \
1386 arch/$(SRCARCH)/include/generated .tmp_objdiff \
1387 debian/ snap/ tar-install/
1388 MRPROPER_FILES += .config .config.old .version \
1390 signing_key.pem signing_key.priv signing_key.x509 \
1391 x509.genkey extra_certificates signing_key.x509.keyid \
1392 signing_key.x509.signer vmlinux-gdb.py \
1395 # Directories & files removed with 'make distclean'
1397 DISTCLEAN_FILES += tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS
1399 # clean - Delete most, but leave enough to build external modules
1401 clean: rm-dirs := $(CLEAN_DIRS)
1402 clean: rm-files := $(CLEAN_FILES)
1404 PHONY += archclean vmlinuxclean
1407 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1408 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1410 clean: archclean vmlinuxclean
1412 # mrproper - Delete all generated files, including .config
1414 mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS))
1415 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1416 mrproper-dirs := $(addprefix _mrproper_,scripts)
1418 PHONY += $(mrproper-dirs) mrproper
1420 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1422 mrproper: clean $(mrproper-dirs)
1428 distclean: rm-dirs := $(wildcard $(DISTCLEAN_DIRS))
1429 distclean: rm-files := $(wildcard $(DISTCLEAN_FILES))
1436 @find $(srctree) $(RCS_FIND_IGNORE) \
1437 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1438 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1439 -o -name 'core' \) \
1440 -type f -print | xargs rm -f
1443 # Packaging of the kernel to various formats
1444 # ---------------------------------------------------------------------------
1447 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1448 %pkg: include/config/kernel.release FORCE
1449 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1451 # Brief documentation of the typical targets used
1452 # ---------------------------------------------------------------------------
1454 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1455 boards := $(sort $(notdir $(boards)))
1456 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1457 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1461 @echo 'Cleaning targets:'
1462 @echo ' clean - Remove most generated files but keep the config and'
1463 @echo ' enough build support to build external modules'
1464 @echo ' mrproper - Remove all generated files + config + various backup files'
1465 @echo ' distclean - mrproper + remove editor backup and patch files'
1467 @echo 'Configuration targets:'
1468 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1470 @echo 'Other generic targets:'
1471 @echo ' all - Build all targets marked with [*]'
1472 @echo '* vmlinux - Build the bare kernel'
1473 @echo '* modules - Build all modules'
1474 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1475 @echo ' dir/ - Build all files in dir and below'
1476 @echo ' dir/file.[ois] - Build specified target only'
1477 @echo ' dir/file.ll - Build the LLVM assembly file'
1478 @echo ' (requires compiler support for LLVM assembly generation)'
1479 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1480 @echo ' (requires a recent binutils and recent build (System.map))'
1481 @echo ' dir/file.ko - Build module including final link'
1482 @echo ' modules_prepare - Set up for building external modules'
1483 @echo ' tags/TAGS - Generate tags file for editors'
1484 @echo ' cscope - Generate cscope index'
1485 @echo ' gtags - Generate GNU GLOBAL index'
1486 @echo ' kernelrelease - Output the release version string (use with make -s)'
1487 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1488 @echo ' image_name - Output the image name (use with make -s)'
1489 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1490 echo ' (default: $(INSTALL_HDR_PATH))'; \
1492 @echo 'Static analysers:'
1493 @echo ' checkstack - Generate a list of stack hogs'
1494 @echo ' namespacecheck - Name space analysis on compiled kernel'
1495 @echo ' versioncheck - Sanity check on version.h usage'
1496 @echo ' includecheck - Check for duplicate included header files'
1497 @echo ' export_report - List the usages of all exported symbols'
1498 @echo ' headers_check - Sanity check on exported headers'
1499 @echo ' headerdep - Detect inclusion cycles in headers'
1500 @echo ' coccicheck - Check with Coccinelle'
1502 @echo 'Kernel selftest:'
1503 @echo ' kselftest - Build and run kernel selftest (run as root)'
1504 @echo ' Build, install, and boot kernel before'
1505 @echo ' running kselftest on it'
1506 @echo ' kselftest-clean - Remove all generated kselftest files'
1507 @echo ' kselftest-merge - Merge all the config dependencies of kselftest to existing'
1511 echo 'Devicetree:'; \
1512 echo '* dtbs - Build device tree blobs for enabled boards'; \
1513 echo ' dtbs_install - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1516 @echo 'Userspace tools targets:'
1517 @echo ' use "make tools/help"'
1518 @echo ' or "cd tools; make help"'
1520 @echo 'Kernel packaging:'
1521 @$(MAKE) -f $(srctree)/scripts/Makefile.package help
1523 @echo 'Documentation targets:'
1524 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1526 @echo 'Architecture specific targets ($(SRCARCH)):'
1527 @$(if $(archhelp),$(archhelp),\
1528 echo ' No architecture specific help defined for $(SRCARCH)')
1531 $(foreach b, $(boards), \
1532 printf " %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1534 @$(if $(board-dirs), \
1535 $(foreach b, $(board-dirs), \
1536 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1537 printf " %-16s - Show all of the above\\n" help-boards; \
1540 @echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1541 @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
1542 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1543 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK (sparse by default)'
1544 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1545 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1546 @echo ' make W=n [targets] Enable extra gcc checks, n=1,2,3 where'
1547 @echo ' 1: warnings which may be relevant and do not occur too often'
1548 @echo ' 2: warnings which occur quite often but may still be relevant'
1549 @echo ' 3: more obscure warnings, can most likely be ignored'
1550 @echo ' Multiple levels can be combined with W=12 or W=123'
1552 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1553 @echo 'For further info see the ./README file'
1556 help-board-dirs := $(addprefix help-,$(board-dirs))
1558 help-boards: $(help-board-dirs)
1560 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1562 $(help-board-dirs): help-%:
1563 @echo 'Architecture specific targets ($(SRCARCH) $*):'
1564 @$(if $(boards-per-dir), \
1565 $(foreach b, $(boards-per-dir), \
1566 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1570 # Documentation targets
1571 # ---------------------------------------------------------------------------
1572 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1573 linkcheckdocs dochelp refcheckdocs
1574 PHONY += $(DOC_TARGETS)
1576 $(Q)$(MAKE) $(build)=Documentation $@
1579 # ---------------------------------------------------------------------------
1581 PHONY += scripts_gdb
1582 scripts_gdb: prepare0
1583 $(Q)$(MAKE) $(build)=scripts/gdb
1584 $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1586 ifdef CONFIG_GDB_SCRIPTS
1590 else # KBUILD_EXTMOD
1593 # External module support.
1594 # When building external modules the kernel used as basis is considered
1595 # read-only, and no consistency checks are made and the make
1596 # system is not used on the basis kernel. If updates are required
1597 # in the basis kernel ordinary make commands (without M=...) must
1600 # The following are the only valid targets when building external
1602 # make M=dir clean Delete all automatically generated files
1603 # make M=dir modules Make all modules in specified dir
1604 # make M=dir Same as 'make M=dir modules'
1605 # make M=dir modules_install
1606 # Install the modules built in the module directory
1607 # Assumes install directory is already created
1609 # We are always building modules
1612 PHONY += $(objtree)/Module.symvers
1613 $(objtree)/Module.symvers:
1614 @test -e $(objtree)/Module.symvers || ( \
1616 echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1617 echo " is missing; modules will have no dependencies and modversions."; \
1620 build-dirs := $(KBUILD_EXTMOD)
1622 modules: descend $(objtree)/Module.symvers
1623 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1625 PHONY += modules_install
1626 modules_install: _emodinst_ _emodinst_post
1628 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1631 $(Q)mkdir -p $(MODLIB)/$(install-dir)
1632 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1634 PHONY += _emodinst_post
1635 _emodinst_post: _emodinst_
1638 clean-dirs := $(KBUILD_EXTMOD)
1639 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1643 @echo >&2 '"$(MAKE) /" is no longer supported. Please use "$(MAKE) ./" instead.'
1647 @echo ' Building external modules.'
1648 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1650 @echo ' modules - default target, build the module(s)'
1651 @echo ' modules_install - install the module'
1652 @echo ' clean - remove generated files in module directory only'
1656 endif # KBUILD_EXTMOD
1658 # Handle descending into subdirectories listed in $(build-dirs)
1659 # Preset locale variables to speed up the build process. Limit locale
1660 # tweaks to this spot to avoid wrong language settings when running
1661 # make menuconfig etc.
1662 # Error messages still appears in the original language
1663 PHONY += descend $(build-dirs)
1664 descend: $(build-dirs)
1665 $(build-dirs): prepare
1666 $(Q)$(MAKE) $(build)=$@ single-build=$(single-build) need-builtin=1 need-modorder=1
1668 clean-dirs := $(addprefix _clean_, $(clean-dirs))
1669 PHONY += $(clean-dirs) clean
1671 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1673 clean: $(clean-dirs)
1676 @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1677 \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1679 -o -name '*.dtb' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1680 -o -name '*.dwo' -o -name '*.lst' \
1681 -o -name '*.su' -o -name '*.mod' \
1682 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1683 -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1684 -o -name '*.asn1.[ch]' \
1685 -o -name '*.symtypes' -o -name 'modules.order' \
1686 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1687 -o -name '*.c.[012]*.*' \
1689 -o -name '*.gcno' \) -type f -print | xargs rm -f
1691 # Generate tags for editors
1692 # ---------------------------------------------------------------------------
1693 quiet_cmd_tags = GEN $@
1694 cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
1696 tags TAGS cscope gtags: FORCE
1699 # Scripts to check various things for consistency
1700 # ---------------------------------------------------------------------------
1702 PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1705 find $(srctree)/* $(RCS_FIND_IGNORE) \
1706 -name '*.[hcS]' -type f -print | sort \
1707 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1710 find $(srctree)/* $(RCS_FIND_IGNORE) \
1711 -name '*.[hcS]' -type f -print | sort \
1712 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1715 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1718 $(PERL) $(srctree)/scripts/namespace.pl
1721 $(PERL) $(srctree)/scripts/export_report.pl
1723 PHONY += checkstack kernelrelease kernelversion image_name
1725 # UML needs a little special treatment here. It wants to use the host
1726 # toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
1727 # else wants $(ARCH), including people doing cross-builds, which means
1728 # that $(SUBARCH) doesn't work here.
1730 CHECKSTACK_ARCH := $(SUBARCH)
1732 CHECKSTACK_ARCH := $(ARCH)
1735 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1736 $(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1739 @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1742 @echo $(KERNELVERSION)
1745 @echo $(KBUILD_IMAGE)
1747 # Clear a bunch of variables before executing the submake
1749 ifeq ($(quiet),silent_)
1754 $(Q)mkdir -p $(objtree)/tools
1755 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1758 $(Q)mkdir -p $(objtree)/tools
1759 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1762 # ---------------------------------------------------------------------------
1763 # To build individual files in subdirectories, you can do like this:
1765 # make foo/bar/baz.s
1767 # The supported suffixes for single-target are listed in 'single-targets'
1769 # To build only under specific subdirectories, you can do like this:
1775 single-all := $(filter $(single-targets), $(MAKECMDGOALS))
1777 # .ko is special because modpost is needed
1778 single-ko := $(sort $(filter %.ko, $(single-all)))
1779 single-no-ko := $(sort $(patsubst %.ko,%.mod, $(single-all)))
1781 $(single-ko): single_modpost
1783 $(single-no-ko): descend
1786 ifeq ($(KBUILD_EXTMOD),)
1787 # For the single build of in-tree modules, use a temporary file to avoid
1788 # the situation of modules_install installing an invalid modules.order.
1789 MODORDER := .modules.tmp
1792 PHONY += single_modpost
1793 single_modpost: $(single-no-ko)
1794 $(Q){ $(foreach m, $(single-ko), echo $(extmod-prefix)$m;) } > $(MODORDER)
1795 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1799 export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod-prefix), $(single-no-ko))
1801 single-build = $(if $(filter-out $@/, $(single-no-ko)),1)
1805 # FIXME Should go into a make.lib or something
1806 # ===========================================================================
1808 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs)))
1809 cmd_rmdirs = rm -rf $(rm-dirs)
1811 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
1812 cmd_rmfiles = rm -f $(rm-files)
1814 # Run depmod only if we have System.map and depmod is executable
1815 quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
1816 cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1819 # read saved command lines for existing targets
1820 existing-targets := $(wildcard $(sort $(targets)))
1822 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1824 endif # config-targets
1826 endif # need-sub-make
1831 # Declare the contents of the PHONY variable as phony. We keep that
1832 # information in a variable so we can use it in if_changed and friends.