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)
215 $(warning Please use 'M=' or 'KBUILD_EXTMOD' instead)
216 $(warning ==========================================)
217 KBUILD_EXTMOD ?= $(SUBDIRS)
220 ifeq ("$(origin M)", "command line")
221 KBUILD_EXTMOD := $(M)
224 ifeq ($(abs_srctree),$(abs_objtree))
225 # building in the source tree
228 ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
229 # building in a subdirectory of the source tree
232 srctree := $(abs_srctree)
236 # KBUILD_SRC is only used to distinguish in-tree/out-of-tree build.
237 # Replace it with $(srctree) or something.
238 KBUILD_SRC := $(abs_srctree)
241 export KBUILD_CHECKSRC KBUILD_EXTMOD KBUILD_SRC
249 export srctree objtree VPATH
251 # To make sure we do not include .config for any of the *config targets
252 # catch them early, and hand them over to scripts/kconfig/Makefile
253 # It is allowed to specify more targets when calling make, including
254 # mixing *config targets and build targets.
255 # For example 'make oldconfig all'.
256 # Detect when mixed targets is specified, and make a second invocation
257 # of make so .config is not included in this case either (for *config).
259 version_h := include/generated/uapi/linux/version.h
260 old_version_h := include/linux/version.h
262 clean-targets := %clean mrproper cleandocs
263 no-dot-config-targets := $(clean-targets) \
264 cscope gtags TAGS tags help% %docs check% coccicheck \
265 $(version_h) headers_% archheaders archscripts \
266 %asm-generic kernelversion %src-pkg
267 no-sync-config-targets := $(no-dot-config-targets) install %install \
275 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
276 ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
281 ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
282 ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
287 ifneq ($(KBUILD_EXTMOD),)
291 ifeq ($(KBUILD_EXTMOD),)
292 ifneq ($(filter config %config,$(MAKECMDGOALS)),)
294 ifneq ($(words $(MAKECMDGOALS)),1)
300 # For "make -j clean all", "make -j mrproper defconfig all", etc.
301 ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
302 ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
307 # install and modules_install need also be processed one by one
308 ifneq ($(filter install,$(MAKECMDGOALS)),)
309 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
314 ifeq ($(mixed-targets),1)
315 # ===========================================================================
316 # We're called with mixed targets (*config and build targets).
317 # Handle them one by one.
319 PHONY += $(MAKECMDGOALS) __build_one_by_one
321 $(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
326 for i in $(MAKECMDGOALS); do \
327 $(MAKE) -f $(srctree)/Makefile $$i; \
332 include scripts/Kbuild.include
334 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
335 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
336 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
337 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
339 include scripts/subarch.include
341 # Cross compiling and selecting different set of gcc/bin-utils
342 # ---------------------------------------------------------------------------
344 # When performing cross compilation for other architectures ARCH shall be set
345 # to the target architecture. (See arch/* for the possibilities).
346 # ARCH can be set during invocation of make:
348 # Another way is to have ARCH set in the environment.
349 # The default ARCH is the host where make is executed.
351 # CROSS_COMPILE specify the prefix used for all executables used
352 # during compilation. Only gcc and related bin-utils executables
353 # are prefixed with $(CROSS_COMPILE).
354 # CROSS_COMPILE can be set on the command line
355 # make CROSS_COMPILE=ia64-linux-
356 # Alternatively CROSS_COMPILE can be set in the environment.
357 # Default value for CROSS_COMPILE is not to prefix executables
358 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
361 # Architecture as present in compile.h
362 UTS_MACHINE := $(ARCH)
365 # Additional ARCH settings for x86
369 ifeq ($(ARCH),x86_64)
373 # Additional ARCH settings for sparc
374 ifeq ($(ARCH),sparc32)
377 ifeq ($(ARCH),sparc64)
381 # Additional ARCH settings for sh
386 KCONFIG_CONFIG ?= .config
387 export KCONFIG_CONFIG
389 # SHELL used by kbuild
390 CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
391 else if [ -x /bin/bash ]; then echo /bin/bash; \
392 else echo sh; fi ; fi)
394 HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
395 HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
396 HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
400 KBUILD_HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 \
401 -fomit-frame-pointer -std=gnu89 $(HOST_LFS_CFLAGS) \
403 KBUILD_HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
404 KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
405 KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
407 # Make variables (CC, etc...)
408 AS = $(CROSS_COMPILE)as
409 LD = $(CROSS_COMPILE)ld
410 CC = $(CROSS_COMPILE)gcc
412 AR = $(CROSS_COMPILE)ar
413 NM = $(CROSS_COMPILE)nm
414 STRIP = $(CROSS_COMPILE)strip
415 OBJCOPY = $(CROSS_COMPILE)objcopy
416 OBJDUMP = $(CROSS_COMPILE)objdump
420 INSTALLKERNEL := installkernel
421 DEPMOD = /sbin/depmod
428 CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
429 -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
438 # Use USERINCLUDE when you must reference the UAPI directories only.
440 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
441 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
442 -I$(srctree)/include/uapi \
443 -I$(objtree)/include/generated/uapi \
444 -include $(srctree)/include/linux/kconfig.h
446 # Use LINUXINCLUDE when you must reference the include/ directory.
447 # Needed to be compatible with the O= option
449 -I$(srctree)/arch/$(SRCARCH)/include \
450 -I$(objtree)/arch/$(SRCARCH)/include/generated \
451 $(if $(filter .,$(srctree)),,-I$(srctree)/include) \
452 -I$(objtree)/include \
455 KBUILD_AFLAGS := -D__ASSEMBLY__ -fno-PIE
456 KBUILD_CFLAGS := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
457 -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
458 -Werror=implicit-function-declaration -Werror=implicit-int \
459 -Wno-format-security \
461 KBUILD_CPPFLAGS := -D__KERNEL__
462 KBUILD_AFLAGS_KERNEL :=
463 KBUILD_CFLAGS_KERNEL :=
464 KBUILD_AFLAGS_MODULE := -DMODULE
465 KBUILD_CFLAGS_MODULE := -DMODULE
466 KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
468 GCC_PLUGINS_CFLAGS :=
470 export ARCH SRCARCH CONFIG_SHELL HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE AS LD CC
471 export CPP AR NM STRIP OBJCOPY OBJDUMP KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS
472 export MAKE LEX YACC AWK INSTALLKERNEL PERL PYTHON PYTHON2 PYTHON3 UTS_MACHINE
473 export HOSTCXX KBUILD_HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
475 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
476 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
477 export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN
478 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
479 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
480 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
481 export KBUILD_ARFLAGS
483 # When compiling out-of-tree modules, put MODVERDIR in the module
484 # tree rather than in the kernel tree. The kernel tree might
486 export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
488 # Files to ignore in find ... statements
490 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
491 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
493 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
494 --exclude CVS --exclude .pc --exclude .hg --exclude .git
496 # ===========================================================================
497 # Rules shared between *config targets and build targets
499 # Basic helpers built in scripts/basic/
500 PHONY += scripts_basic
502 $(Q)$(MAKE) $(build)=scripts/basic
503 $(Q)rm -f .tmp_quiet_recordmcount
505 PHONY += outputmakefile
506 # outputmakefile generates a Makefile in the output directory, if using a
507 # separate output directory. This allows convenient use of make in the
509 # At the same time when output Makefile generated, generate .gitignore to
510 # ignore whole output directory
513 $(Q)ln -fsn $(srctree) source
514 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
515 $(Q)test -e .gitignore || \
516 { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
519 ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
520 ifneq ($(CROSS_COMPILE),)
521 CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE:%-=%))
522 GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
523 CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)
524 GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..)
526 ifneq ($(GCC_TOOLCHAIN),)
527 CLANG_FLAGS += --gcc-toolchain=$(GCC_TOOLCHAIN)
529 CLANG_FLAGS += -no-integrated-as
530 KBUILD_CFLAGS += $(CLANG_FLAGS)
531 KBUILD_AFLAGS += $(CLANG_FLAGS)
535 # The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
536 # Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
537 # CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
538 # and from include/config/auto.conf.cmd to detect the compiler upgrade.
539 CC_VERSION_TEXT = $(shell $(CC) --version | head -n 1)
541 ifeq ($(config-targets),1)
542 # ===========================================================================
543 # *config targets only - make sure prerequisites are updated, and descend
544 # in scripts/kconfig to make the *config target
546 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
547 # KBUILD_DEFCONFIG may point out an alternative default configuration
548 # used for 'make defconfig'
549 include arch/$(SRCARCH)/Makefile
550 export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
552 config: scripts_basic outputmakefile FORCE
553 $(Q)$(MAKE) $(build)=scripts/kconfig $@
555 %config: scripts_basic outputmakefile FORCE
556 $(Q)$(MAKE) $(build)=scripts/kconfig $@
559 # ===========================================================================
560 # Build targets only - this includes vmlinux, arch specific targets, clean
561 # targets and others. In general all targets except *config targets.
563 # If building an external module we do not care about the all: rule
564 # but instead _all depend on modules
566 ifeq ($(KBUILD_EXTMOD),)
572 # Decide whether to build built-in, modular, or both.
573 # Normally, just do built-in.
578 # If we have only "make modules", don't compile built-in objects.
579 # When we're building modules with modversions, we need to consider
580 # the built-in objects during the descend as well, in order to
581 # make sure the checksums are up to date before we record them.
583 ifeq ($(MAKECMDGOALS),modules)
584 KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
587 # If we have "make <whatever> modules", compile modules
588 # in addition to whatever we do anyway.
589 # Just "make" or "make all" shall build modules as well
591 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
595 ifeq ($(MAKECMDGOALS),)
599 export KBUILD_MODULES KBUILD_BUILTIN
601 ifeq ($(dot-config),1)
602 include include/config/auto.conf
605 ifeq ($(KBUILD_EXTMOD),)
606 # Objects we will link into vmlinux / subdirs we need to visit
608 drivers-y := drivers/ sound/
609 drivers-$(CONFIG_SAMPLES) += samples/
614 endif # KBUILD_EXTMOD
616 # The all: target is the default when no target is given on the
618 # This allow a user to issue only 'make' to build a kernel including modules
619 # Defaults to vmlinux, but the arch makefile usually adds further targets
622 CFLAGS_GCOV := -fprofile-arcs -ftest-coverage \
623 $(call cc-option,-fno-tree-loop-im) \
624 $(call cc-disable-warning,maybe-uninitialized,)
627 # The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
628 ifdef CONFIG_FUNCTION_TRACER
629 CC_FLAGS_FTRACE := -pg
632 RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
633 RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
634 RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
635 RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
636 RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
637 RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
638 export RETPOLINE_CFLAGS
639 export RETPOLINE_VDSO_CFLAGS
641 # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
642 # values of the respective KBUILD_* variables
646 include arch/$(SRCARCH)/Makefile
648 ifeq ($(dot-config),1)
649 ifeq ($(may-sync-config),1)
650 # Read in dependencies to all Kconfig* files, make sure to run syncconfig if
651 # changes are detected. This should be included after arch/$(SRCARCH)/Makefile
652 # because some architectures define CROSS_COMPILE there.
653 -include include/config/auto.conf.cmd
657 @echo >&2 '*** Configuration file "$@" not found!'
659 @echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
660 @echo >&2 '*** "make menuconfig" or "make xconfig").'
664 # The actual configuration files used during the build are stored in
665 # include/generated/ and include/config/. Update them if .config is newer than
666 # include/config/auto.conf (which mirrors .config).
668 # This exploits the 'multi-target pattern rule' trick.
669 # The syncconfig should be executed only once to make all the targets.
670 %/auto.conf %/auto.conf.cmd %/tristate.conf: $(KCONFIG_CONFIG)
671 $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
673 # External modules and some install targets need include/generated/autoconf.h
674 # and include/config/auto.conf but do not care if they are up-to-date.
675 # Use auto.conf to trigger the test
676 PHONY += include/config/auto.conf
678 include/config/auto.conf:
679 $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
681 echo >&2 " ERROR: Kernel configuration is invalid."; \
682 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
683 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
687 endif # may-sync-config
688 endif # $(dot-config)
690 KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
691 KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
692 KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
693 KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
694 KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context)
696 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
702 ifdef CONFIG_CC_DISABLE_WARN_MAYBE_UNINITIALIZED
703 KBUILD_CFLAGS += -Wno-maybe-uninitialized
706 # Tell gcc to never replace conditional load with a non-conditional one
707 KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
709 include scripts/Makefile.kcov
710 include scripts/Makefile.gcc-plugins
712 ifdef CONFIG_READABLE_ASM
713 # Disable optimizations that make assembler listings hard to read.
714 # reorder blocks reorders the control in the function
715 # ipa clone creates specialized cloned functions
716 # partial inlining inlines only parts of functions
717 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
718 $(call cc-option,-fno-ipa-cp-clone,) \
719 $(call cc-option,-fno-partial-inlining)
722 ifneq ($(CONFIG_FRAME_WARN),0)
723 KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
726 stackp-flags-$(CONFIG_CC_HAS_STACKPROTECTOR_NONE) := -fno-stack-protector
727 stackp-flags-$(CONFIG_STACKPROTECTOR) := -fstack-protector
728 stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong
730 KBUILD_CFLAGS += $(stackp-flags-y)
732 ifdef CONFIG_CC_IS_CLANG
733 KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
734 KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
735 KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
736 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
737 # Quiet clang warning: comparison of unsigned expression < 0 is always false
738 KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
739 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
740 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
741 # See modpost pattern 2
742 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
743 KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
746 # These warnings generated too much noise in a regular build.
747 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
748 KBUILD_CFLAGS += -Wno-unused-but-set-variable
751 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
752 ifdef CONFIG_FRAME_POINTER
753 KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
755 # Some targets (ARM with Thumb2, for example), can't be built with frame
756 # pointers. For those, we don't have FUNCTION_TRACER automatically
757 # select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
758 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
759 # -fomit-frame-pointer with FUNCTION_TRACER.
760 ifndef CONFIG_FUNCTION_TRACER
761 KBUILD_CFLAGS += -fomit-frame-pointer
765 DEBUG_CFLAGS := $(call cc-option, -fno-var-tracking-assignments)
767 ifdef CONFIG_DEBUG_INFO
768 ifdef CONFIG_DEBUG_INFO_SPLIT
769 DEBUG_CFLAGS += -gsplit-dwarf
773 KBUILD_AFLAGS += -Wa,-gdwarf-2
775 ifdef CONFIG_DEBUG_INFO_DWARF4
776 DEBUG_CFLAGS += -gdwarf-4
779 ifdef CONFIG_DEBUG_INFO_REDUCED
780 DEBUG_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
781 $(call cc-option,-fno-var-tracking)
784 KBUILD_CFLAGS += $(DEBUG_CFLAGS)
787 ifdef CONFIG_FUNCTION_TRACER
788 ifdef CONFIG_FTRACE_MCOUNT_RECORD
789 # gcc 5 supports generating the mcount tables directly
790 ifeq ($(call cc-option-yn,-mrecord-mcount),y)
791 CC_FLAGS_FTRACE += -mrecord-mcount
792 export CC_USING_RECORD_MCOUNT := 1
794 ifdef CONFIG_HAVE_NOP_MCOUNT
795 ifeq ($(call cc-option-yn, -mnop-mcount),y)
796 CC_FLAGS_FTRACE += -mnop-mcount
797 CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
801 ifdef CONFIG_HAVE_FENTRY
802 ifeq ($(call cc-option-yn, -mfentry),y)
803 CC_FLAGS_FTRACE += -mfentry
804 CC_FLAGS_USING += -DCC_USING_FENTRY
807 export CC_FLAGS_FTRACE
808 KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
809 KBUILD_AFLAGS += $(CC_FLAGS_USING)
810 ifdef CONFIG_DYNAMIC_FTRACE
811 ifdef CONFIG_HAVE_C_RECORDMCOUNT
812 BUILD_C_RECORDMCOUNT := y
813 export BUILD_C_RECORDMCOUNT
818 # We trigger additional mismatches with less inlining
819 ifdef CONFIG_DEBUG_SECTION_MISMATCH
820 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
823 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
824 KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
825 LDFLAGS_vmlinux += --gc-sections
828 # arch Makefile may override CC so keep this after arch Makefile is included
829 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
831 # warn about C99 declaration after statement
832 KBUILD_CFLAGS += -Wdeclaration-after-statement
834 # Variable Length Arrays (VLAs) should not be used anywhere in the kernel
835 KBUILD_CFLAGS += $(call cc-option,-Wvla)
837 # disable pointer signed / unsigned warnings in gcc 4.0
838 KBUILD_CFLAGS += -Wno-pointer-sign
840 # disable stringop warnings in gcc 8+
841 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
843 # disable invalid "can't wrap" optimizations for signed / pointers
844 KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
846 # clang sets -fmerge-all-constants by default as optimization, but this
847 # is non-conforming behavior for C and in fact breaks the kernel, so we
848 # need to disable it here generally.
849 KBUILD_CFLAGS += $(call cc-option,-fno-merge-all-constants)
851 # for gcc -fno-merge-all-constants disables everything, but it is fine
852 # to have actual conforming behavior enabled.
853 KBUILD_CFLAGS += $(call cc-option,-fmerge-constants)
855 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
856 KBUILD_CFLAGS += $(call cc-option,-fno-stack-check,)
858 # conserve stack if available
859 KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
861 # Prohibit date/time macros, which would make the build non-deterministic
862 KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
864 # enforce correct pointer usage
865 KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
867 # Require designated initializers for all marked structures
868 KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
870 # change __FILE__ to the relative path from the srctree
871 KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
873 # use the deterministic mode of AR if available
874 KBUILD_ARFLAGS := $(call ar-option,D)
876 include scripts/Makefile.kasan
877 include scripts/Makefile.extrawarn
878 include scripts/Makefile.ubsan
880 # Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
882 KBUILD_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS)
883 KBUILD_AFLAGS += $(ARCH_AFLAGS) $(KAFLAGS)
884 KBUILD_CFLAGS += $(ARCH_CFLAGS) $(KCFLAGS)
886 # Use --build-id when available.
887 LDFLAGS_BUILD_ID := $(call ld-option, --build-id)
888 KBUILD_LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
889 LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
891 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
892 LDFLAGS_vmlinux += $(call ld-option, -X,)
895 # insure the checker run with the right endianness
896 CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
898 # the checker needs the correct machine size
899 CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
901 # Default kernel image to build when no specific target is given.
902 # KBUILD_IMAGE may be overruled on the command line or
903 # set in the environment
904 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
906 export KBUILD_IMAGE ?= vmlinux
909 # INSTALL_PATH specifies where to place the updated kernel and system map
910 # images. Default is /boot, but you can set it to other values
911 export INSTALL_PATH ?= /boot
914 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
915 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
916 # an argument if needed. Otherwise it defaults to the kernel install path
918 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
921 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
922 # relocations required by build roots. This is not defined in the
923 # makefile but the argument can be passed to make if needed.
926 MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
930 # INSTALL_MOD_STRIP, if defined, will cause modules to be
931 # stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
932 # the default option --strip-debug will be used. Otherwise,
933 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
935 ifdef INSTALL_MOD_STRIP
936 ifeq ($(INSTALL_MOD_STRIP),1)
937 mod_strip_cmd = $(STRIP) --strip-debug
939 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
940 endif # INSTALL_MOD_STRIP=1
943 endif # INSTALL_MOD_STRIP
946 # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
947 # after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
948 # or CONFIG_MODULE_COMPRESS_XZ.
950 mod_compress_cmd = true
951 ifdef CONFIG_MODULE_COMPRESS
952 ifdef CONFIG_MODULE_COMPRESS_GZIP
953 mod_compress_cmd = gzip -n -f
954 endif # CONFIG_MODULE_COMPRESS_GZIP
955 ifdef CONFIG_MODULE_COMPRESS_XZ
956 mod_compress_cmd = xz -f
957 endif # CONFIG_MODULE_COMPRESS_XZ
958 endif # CONFIG_MODULE_COMPRESS
959 export mod_compress_cmd
961 ifdef CONFIG_MODULE_SIG_ALL
962 $(eval $(call config_filename,MODULE_SIG_KEY))
964 mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
970 HOST_LIBELF_LIBS = $(shell pkg-config libelf --libs 2>/dev/null || echo -lelf)
972 ifdef CONFIG_STACK_VALIDATION
973 has_libelf := $(call try-run,\
974 echo "int main() {}" | $(HOSTCC) -xc -o /dev/null $(HOST_LIBELF_LIBS) -,1,0)
975 ifeq ($(has_libelf),1)
976 objtool_target := tools/objtool FORCE
978 SKIP_STACK_VALIDATION := 1
979 export SKIP_STACK_VALIDATION
985 ifeq ($(KBUILD_EXTMOD),)
986 core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
988 vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
989 $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
990 $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
992 vmlinux-alldirs := $(sort $(vmlinux-dirs) Documentation \
993 $(patsubst %/,%,$(filter %/, $(init-) $(core-) \
994 $(drivers-) $(net-) $(libs-) $(virt-))))
996 init-y := $(patsubst %/, %/built-in.a, $(init-y))
997 core-y := $(patsubst %/, %/built-in.a, $(core-y))
998 drivers-y := $(patsubst %/, %/built-in.a, $(drivers-y))
999 net-y := $(patsubst %/, %/built-in.a, $(net-y))
1000 libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
1001 libs-y2 := $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y)))
1002 virt-y := $(patsubst %/, %/built-in.a, $(virt-y))
1004 # Externally visible symbols (used by link-vmlinux.sh)
1005 export KBUILD_VMLINUX_OBJS := $(head-y) $(init-y) $(core-y) $(libs-y2) \
1006 $(drivers-y) $(net-y) $(virt-y)
1007 export KBUILD_VMLINUX_LIBS := $(libs-y1)
1008 export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
1009 export LDFLAGS_vmlinux
1010 # used by scripts/package/Makefile
1011 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch include scripts tools)
1013 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1015 # Recurse until adjust_autoksyms.sh is satisfied
1016 PHONY += autoksyms_recursive
1017 autoksyms_recursive: $(vmlinux-deps)
1018 ifdef CONFIG_TRIM_UNUSED_KSYMS
1019 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1020 "$(MAKE) -f $(srctree)/Makefile vmlinux"
1023 # For the kernel to actually contain only the needed exported symbols,
1024 # we have to build modules as well to determine what those symbols are.
1025 # (this can be evaluated only once include/config/auto.conf has been included)
1026 ifdef CONFIG_TRIM_UNUSED_KSYMS
1030 autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1033 $(Q)mkdir -p $(dir $@)
1036 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1038 # Final link of vmlinux with optional arch pass after final link
1039 cmd_link-vmlinux = \
1040 $(CONFIG_SHELL) $< $(LD) $(KBUILD_LDFLAGS) $(LDFLAGS_vmlinux) ; \
1041 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1043 vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1044 +$(call if_changed,link-vmlinux)
1048 # Some samples need headers_install.
1049 samples: headers_install
1051 # The actual objects are generated when descending,
1052 # make sure no implicit rule kicks in
1053 $(sort $(vmlinux-deps)): $(vmlinux-dirs) ;
1055 # Handle descending into subdirectories listed in $(vmlinux-dirs)
1056 # Preset locale variables to speed up the build process. Limit locale
1057 # tweaks to this spot to avoid wrong language settings when running
1058 # make menuconfig etc.
1059 # Error messages still appears in the original language
1061 PHONY += $(vmlinux-dirs)
1062 $(vmlinux-dirs): prepare
1063 $(Q)$(MAKE) $(build)=$@ need-builtin=1
1065 filechk_kernel.release = \
1066 echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1068 # Store (new) KERNELRELEASE string in include/config/kernel.release
1069 include/config/kernel.release: FORCE
1070 $(call filechk,kernel.release)
1072 # Additional helpers built in scripts/
1073 # Carefully list dependencies so we do not try to build scripts twice
1076 scripts: scripts_basic scripts_dtc
1077 $(Q)$(MAKE) $(build)=$(@)
1079 # Things we need to do before we recursively start building the kernel
1080 # or the modules are listed in "prepare".
1081 # A multi level approach is used. prepareN is processed before prepareN-1.
1082 # archprepare is used in arch Makefiles and when processed asm symlink,
1083 # version.h and scripts_basic is processed / created.
1085 PHONY += prepare archprepare prepare1 prepare3
1087 # prepare3 is used to check if we are building in a separate output directory,
1089 # 1) Check that make has not been executed in the kernel src $(srctree)
1090 prepare3: include/config/kernel.release
1091 ifneq ($(srctree),.)
1092 @$(kecho) ' Using $(srctree) as source for kernel'
1093 $(Q)if [ -f $(srctree)/.config -o \
1094 -d $(srctree)/include/config -o \
1095 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
1096 echo >&2 " $(srctree) is not clean, please run 'make mrproper'"; \
1097 echo >&2 " in the '$(srctree)' directory.";\
1102 prepare1: prepare3 outputmakefile asm-generic $(version_h) $(autoksyms_h) \
1103 include/generated/utsrelease.h
1106 archprepare: archheaders archscripts prepare1 scripts
1108 prepare0: archprepare
1109 $(Q)$(MAKE) $(build)=scripts/mod
1110 $(Q)$(MAKE) $(build)=.
1112 # All the preparing..
1113 prepare: prepare0 prepare-objtool
1115 # Support for using generic headers in asm-generic
1116 asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1118 PHONY += asm-generic uapi-asm-generic
1119 asm-generic: uapi-asm-generic
1120 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1121 generic=include/asm-generic
1123 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1124 generic=include/uapi/asm-generic
1126 PHONY += prepare-objtool
1127 prepare-objtool: $(objtool_target)
1128 ifeq ($(SKIP_STACK_VALIDATION),1)
1129 ifdef CONFIG_UNWINDER_ORC
1130 @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1133 @echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1137 # Generate some files
1138 # ---------------------------------------------------------------------------
1140 # KERNELRELEASE can change from a few different places, meaning version.h
1141 # needs to be updated, so this check is forced on all builds
1144 define filechk_utsrelease.h
1145 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1146 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1149 echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1152 define filechk_version.h
1153 echo \#define LINUX_VERSION_CODE $(shell \
1154 expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
1155 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))'
1159 $(call filechk,version.h)
1160 $(Q)rm -f $(old_version_h)
1162 include/generated/utsrelease.h: include/config/kernel.release FORCE
1163 $(call filechk,utsrelease.h)
1167 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1168 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1170 # ---------------------------------------------------------------------------
1173 #Default location for installed headers
1174 export INSTALL_HDR_PATH = $(objtree)/usr
1176 # If we do an all arch process set dst to include/arch-$(SRCARCH)
1177 hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(SRCARCH), dst=include)
1179 PHONY += archheaders archscripts
1182 __headers: $(version_h) scripts_basic uapi-asm-generic archheaders archscripts
1183 $(Q)$(MAKE) $(build)=scripts build_unifdef
1185 PHONY += headers_install_all
1186 headers_install_all:
1187 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh install
1189 PHONY += headers_install
1190 headers_install: __headers
1191 $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1192 $(error Headers not exportable for the $(SRCARCH) architecture))
1193 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include
1194 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst)
1196 PHONY += headers_check_all
1197 headers_check_all: headers_install_all
1198 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh check
1200 PHONY += headers_check
1201 headers_check: headers_install
1202 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include HDRCHECK=1
1203 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst) HDRCHECK=1
1205 ifdef CONFIG_HEADERS_CHECK
1209 # ---------------------------------------------------------------------------
1214 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1216 PHONY += kselftest-clean
1218 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests clean
1220 PHONY += kselftest-merge
1222 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1223 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \
1224 -m $(objtree)/.config \
1225 $(srctree)/tools/testing/selftests/*/config
1226 +$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1228 # ---------------------------------------------------------------------------
1231 ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1232 dtstree := arch/$(SRCARCH)/boot/dts
1237 %.dtb: prepare3 scripts_dtc
1238 $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1240 PHONY += dtbs dtbs_install dt_binding_check
1241 dtbs dtbs_check: prepare3 scripts_dtc
1242 $(Q)$(MAKE) $(build)=$(dtstree)
1244 dtbs_check: export CHECK_DTBS=1
1245 dtbs_check: dt_binding_check
1248 $(Q)$(MAKE) $(dtbinst)=$(dtstree)
1250 ifdef CONFIG_OF_EARLY_FLATTREE
1256 PHONY += scripts_dtc
1257 scripts_dtc: scripts_basic
1258 $(Q)$(MAKE) $(build)=scripts/dtc
1260 dt_binding_check: scripts_dtc
1261 $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1263 # ---------------------------------------------------------------------------
1266 ifdef CONFIG_MODULES
1268 # By default, build modules as well
1274 # A module can be listed more than once in obj-m resulting in
1275 # duplicate lines in modules.order files. Those are removed
1276 # using awk while concatenating to the final file.
1279 modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
1280 $(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
1281 @$(kecho) ' Building modules, stage 2.';
1282 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1284 modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
1285 $(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
1287 %/modules.builtin: include/config/auto.conf include/config/tristate.conf
1288 $(Q)$(MAKE) $(modbuiltin)=$*
1291 # Target to prepare building external modules
1292 PHONY += modules_prepare
1293 modules_prepare: prepare
1295 # Target to install modules
1296 PHONY += modules_install
1297 modules_install: _modinst_ _modinst_post
1301 @rm -rf $(MODLIB)/kernel
1302 @rm -f $(MODLIB)/source
1303 @mkdir -p $(MODLIB)/kernel
1304 @ln -s $(abspath $(srctree)) $(MODLIB)/source
1305 @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
1306 rm -f $(MODLIB)/build ; \
1307 ln -s $(CURDIR) $(MODLIB)/build ; \
1309 @cp -f $(objtree)/modules.order $(MODLIB)/
1310 @cp -f $(objtree)/modules.builtin $(MODLIB)/
1311 @cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1312 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1314 # This depmod is only for convenience to give the initial
1315 # boot a modules.dep even before / is mounted read-write. However the
1316 # boot script depmod is the master version.
1317 PHONY += _modinst_post
1318 _modinst_post: _modinst_
1321 ifeq ($(CONFIG_MODULE_SIG), y)
1322 PHONY += modules_sign
1324 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1327 else # CONFIG_MODULES
1329 # Modules not configured
1330 # ---------------------------------------------------------------------------
1332 PHONY += modules modules_install
1333 modules modules_install:
1335 @echo >&2 "The present kernel configuration has modules disabled."
1336 @echo >&2 "Type 'make config' and enable loadable module support."
1337 @echo >&2 "Then build a kernel with module support enabled."
1341 endif # CONFIG_MODULES
1344 # Cleaning is done on three levels.
1345 # make clean Delete most generated files
1346 # Leave enough to build external modules
1347 # make mrproper Delete the current configuration, and all generated files
1348 # make distclean Remove editor backup files, patch leftover files and the like
1350 # Directories & files removed with 'make clean'
1351 CLEAN_DIRS += $(MODVERDIR) include/ksym
1352 CLEAN_FILES += modules.builtin.modinfo
1354 # Directories & files removed with 'make mrproper'
1355 MRPROPER_DIRS += include/config usr/include include/generated \
1356 arch/$(SRCARCH)/include/generated .tmp_objdiff
1357 MRPROPER_FILES += .config .config.old .version \
1358 Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
1359 signing_key.pem signing_key.priv signing_key.x509 \
1360 x509.genkey extra_certificates signing_key.x509.keyid \
1361 signing_key.x509.signer vmlinux-gdb.py
1363 # clean - Delete most, but leave enough to build external modules
1365 clean: rm-dirs := $(CLEAN_DIRS)
1366 clean: rm-files := $(CLEAN_FILES)
1367 clean-dirs := $(addprefix _clean_, . $(vmlinux-alldirs))
1369 PHONY += $(clean-dirs) clean archclean vmlinuxclean
1371 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1374 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1375 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1377 clean: archclean vmlinuxclean
1379 # mrproper - Delete all generated files, including .config
1381 mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS))
1382 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1383 mrproper-dirs := $(addprefix _mrproper_,scripts)
1385 PHONY += $(mrproper-dirs) mrproper
1387 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1389 mrproper: clean $(mrproper-dirs)
1398 @find $(srctree) $(RCS_FIND_IGNORE) \
1399 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1400 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1401 -o -name 'core' \) \
1402 -type f -print | xargs rm -f
1405 # Packaging of the kernel to various formats
1406 # ---------------------------------------------------------------------------
1407 package-dir := scripts/package
1410 $(Q)$(MAKE) $(build)=$(package-dir) $@
1411 %pkg: include/config/kernel.release FORCE
1412 $(Q)$(MAKE) $(build)=$(package-dir) $@
1415 # Brief documentation of the typical targets used
1416 # ---------------------------------------------------------------------------
1418 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1419 boards := $(sort $(notdir $(boards)))
1420 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1421 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1425 @echo 'Cleaning targets:'
1426 @echo ' clean - Remove most generated files but keep the config and'
1427 @echo ' enough build support to build external modules'
1428 @echo ' mrproper - Remove all generated files + config + various backup files'
1429 @echo ' distclean - mrproper + remove editor backup and patch files'
1431 @echo 'Configuration targets:'
1432 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1434 @echo 'Other generic targets:'
1435 @echo ' all - Build all targets marked with [*]'
1436 @echo '* vmlinux - Build the bare kernel'
1437 @echo '* modules - Build all modules'
1438 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1439 @echo ' dir/ - Build all files in dir and below'
1440 @echo ' dir/file.[ois] - Build specified target only'
1441 @echo ' dir/file.ll - Build the LLVM assembly file'
1442 @echo ' (requires compiler support for LLVM assembly generation)'
1443 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1444 @echo ' (requires a recent binutils and recent build (System.map))'
1445 @echo ' dir/file.ko - Build module including final link'
1446 @echo ' modules_prepare - Set up for building external modules'
1447 @echo ' tags/TAGS - Generate tags file for editors'
1448 @echo ' cscope - Generate cscope index'
1449 @echo ' gtags - Generate GNU GLOBAL index'
1450 @echo ' kernelrelease - Output the release version string (use with make -s)'
1451 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1452 @echo ' image_name - Output the image name (use with make -s)'
1453 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1454 echo ' (default: $(INSTALL_HDR_PATH))'; \
1456 @echo 'Static analysers:'
1457 @echo ' checkstack - Generate a list of stack hogs'
1458 @echo ' namespacecheck - Name space analysis on compiled kernel'
1459 @echo ' versioncheck - Sanity check on version.h usage'
1460 @echo ' includecheck - Check for duplicate included header files'
1461 @echo ' export_report - List the usages of all exported symbols'
1462 @echo ' headers_check - Sanity check on exported headers'
1463 @echo ' headerdep - Detect inclusion cycles in headers'
1464 @echo ' coccicheck - Check with Coccinelle'
1466 @echo 'Kernel selftest:'
1467 @echo ' kselftest - Build and run kernel selftest (run as root)'
1468 @echo ' Build, install, and boot kernel before'
1469 @echo ' running kselftest on it'
1470 @echo ' kselftest-clean - Remove all generated kselftest files'
1471 @echo ' kselftest-merge - Merge all the config dependencies of kselftest to existing'
1475 echo 'Devicetree:'; \
1476 echo '* dtbs - Build device tree blobs for enabled boards'; \
1477 echo ' dtbs_install - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1480 @echo 'Userspace tools targets:'
1481 @echo ' use "make tools/help"'
1482 @echo ' or "cd tools; make help"'
1484 @echo 'Kernel packaging:'
1485 @$(MAKE) $(build)=$(package-dir) help
1487 @echo 'Documentation targets:'
1488 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1490 @echo 'Architecture specific targets ($(SRCARCH)):'
1491 @$(if $(archhelp),$(archhelp),\
1492 echo ' No architecture specific help defined for $(SRCARCH)')
1495 $(foreach b, $(boards), \
1496 printf " %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1498 @$(if $(board-dirs), \
1499 $(foreach b, $(board-dirs), \
1500 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1501 printf " %-16s - Show all of the above\\n" help-boards; \
1504 @echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1505 @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
1506 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1507 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK (sparse by default)'
1508 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1509 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1510 @echo ' make W=n [targets] Enable extra gcc checks, n=1,2,3 where'
1511 @echo ' 1: warnings which may be relevant and do not occur too often'
1512 @echo ' 2: warnings which occur quite often but may still be relevant'
1513 @echo ' 3: more obscure warnings, can most likely be ignored'
1514 @echo ' Multiple levels can be combined with W=12 or W=123'
1516 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1517 @echo 'For further info see the ./README file'
1520 help-board-dirs := $(addprefix help-,$(board-dirs))
1522 help-boards: $(help-board-dirs)
1524 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1526 $(help-board-dirs): help-%:
1527 @echo 'Architecture specific targets ($(SRCARCH) $*):'
1528 @$(if $(boards-per-dir), \
1529 $(foreach b, $(boards-per-dir), \
1530 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1534 # Documentation targets
1535 # ---------------------------------------------------------------------------
1536 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1537 linkcheckdocs dochelp refcheckdocs
1538 PHONY += $(DOC_TARGETS)
1539 $(DOC_TARGETS): scripts_basic FORCE
1540 $(Q)$(MAKE) $(build)=Documentation $@
1543 # ---------------------------------------------------------------------------
1545 PHONY += scripts_gdb
1546 scripts_gdb: prepare
1547 $(Q)$(MAKE) $(build)=scripts/gdb
1548 $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1550 ifdef CONFIG_GDB_SCRIPTS
1554 else # KBUILD_EXTMOD
1557 # External module support.
1558 # When building external modules the kernel used as basis is considered
1559 # read-only, and no consistency checks are made and the make
1560 # system is not used on the basis kernel. If updates are required
1561 # in the basis kernel ordinary make commands (without M=...) must
1564 # The following are the only valid targets when building external
1566 # make M=dir clean Delete all automatically generated files
1567 # make M=dir modules Make all modules in specified dir
1568 # make M=dir Same as 'make M=dir modules'
1569 # make M=dir modules_install
1570 # Install the modules built in the module directory
1571 # Assumes install directory is already created
1573 # We are always building modules
1576 PHONY += $(objtree)/Module.symvers
1577 $(objtree)/Module.symvers:
1578 @test -e $(objtree)/Module.symvers || ( \
1580 echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1581 echo " is missing; modules will have no dependencies and modversions."; \
1584 module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
1585 PHONY += $(module-dirs) modules
1586 $(module-dirs): prepare $(objtree)/Module.symvers
1587 $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
1589 modules: $(module-dirs)
1590 @$(kecho) ' Building modules, stage 2.';
1591 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1593 PHONY += modules_install
1594 modules_install: _emodinst_ _emodinst_post
1596 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1599 $(Q)mkdir -p $(MODLIB)/$(install-dir)
1600 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1602 PHONY += _emodinst_post
1603 _emodinst_post: _emodinst_
1606 clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))
1608 PHONY += $(clean-dirs) clean
1610 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1612 clean: rm-dirs := $(MODVERDIR)
1613 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1617 @echo ' Building external modules.'
1618 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1620 @echo ' modules - default target, build the module(s)'
1621 @echo ' modules_install - install the module'
1622 @echo ' clean - remove generated files in module directory only'
1628 endif # KBUILD_EXTMOD
1630 clean: $(clean-dirs)
1633 @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1634 \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1636 -o -name '*.dtb' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1637 -o -name '*.dwo' -o -name '*.lst' \
1639 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1640 -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1641 -o -name '*.asn1.[ch]' \
1642 -o -name '*.symtypes' -o -name 'modules.order' \
1643 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1644 -o -name '*.c.[012]*.*' \
1646 -o -name '*.gcno' \) -type f -print | xargs rm -f
1648 # Generate tags for editors
1649 # ---------------------------------------------------------------------------
1650 quiet_cmd_tags = GEN $@
1651 cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
1653 tags TAGS cscope gtags: FORCE
1656 # Scripts to check various things for consistency
1657 # ---------------------------------------------------------------------------
1659 PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1662 find $(srctree)/* $(RCS_FIND_IGNORE) \
1663 -name '*.[hcS]' -type f -print | sort \
1664 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1667 find $(srctree)/* $(RCS_FIND_IGNORE) \
1668 -name '*.[hcS]' -type f -print | sort \
1669 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1672 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1675 $(PERL) $(srctree)/scripts/namespace.pl
1678 $(PERL) $(srctree)/scripts/export_report.pl
1680 PHONY += checkstack kernelrelease kernelversion image_name
1682 # UML needs a little special treatment here. It wants to use the host
1683 # toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
1684 # else wants $(ARCH), including people doing cross-builds, which means
1685 # that $(SUBARCH) doesn't work here.
1687 CHECKSTACK_ARCH := $(SUBARCH)
1689 CHECKSTACK_ARCH := $(ARCH)
1692 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1693 $(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1696 @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1699 @echo $(KERNELVERSION)
1702 @echo $(KBUILD_IMAGE)
1704 # Clear a bunch of variables before executing the submake
1706 ifeq ($(quiet),silent_)
1711 $(Q)mkdir -p $(objtree)/tools
1712 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/
1715 $(Q)mkdir -p $(objtree)/tools
1716 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/ $*
1719 # ---------------------------------------------------------------------------
1720 # Single targets are compatible with:
1721 # - build with mixed source and output
1722 # - build with separate output dir 'make O=...'
1723 # - external modules
1725 # target-dir => where to store outputfile
1726 # build-dir => directory in kernel source tree to use
1728 build-target = $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD)/)$@
1729 build-dir = $(patsubst %/,%,$(dir $(build-target)))
1732 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1734 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1735 %.lst: prepare FORCE
1736 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1738 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1740 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1741 %.symtypes: prepare FORCE
1742 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1744 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1750 # Make sure the latest headers are built for Documentation
1751 Documentation/ samples/: headers_install
1753 $(Q)$(MAKE) KBUILD_MODULES=1 $(build)=$(build-dir)
1755 # FIXME Should go into a make.lib or something
1756 # ===========================================================================
1758 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs)))
1759 cmd_rmdirs = rm -rf $(rm-dirs)
1761 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
1762 cmd_rmfiles = rm -f $(rm-files)
1764 # Run depmod only if we have System.map and depmod is executable
1765 quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
1766 cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1769 # Create temporary dir for module support files
1770 # clean it up only when building all modules
1771 cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
1772 $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
1774 # read saved command lines for existing targets
1775 existing-targets := $(wildcard $(sort $(targets)))
1777 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1779 endif # ifeq ($(config-targets),1)
1780 endif # ifeq ($(mixed-targets),1)
1781 endif # need-sub-make
1786 # Declare the contents of the PHONY variable as phony. We keep that
1787 # information in a variable so we can use it in if_changed and friends.