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 # Do not use make's built-in rules and variables
19 # (this increases performance and avoids hard-to-debug behaviour)
22 # Avoid funny character set dependencies
26 export LC_COLLATE LC_NUMERIC
28 # Avoid interference with shell env settings
31 # We are using a recursive build, so we need to do a little thinking
32 # to get the ordering right.
34 # Most importantly: sub-Makefiles should only ever modify files in
35 # their own directory. If in some directory we have a dependency on
36 # a file in another dir (which doesn't happen often, but it's often
37 # unavoidable when linking the built-in.a targets which finally
38 # turn into vmlinux), we will call a sub make in that other dir, and
39 # after that we are sure that everything which is in that other dir
42 # The only cases where we need to modify files which have global
43 # effects are thus separated out and done before the recursive
44 # descending is started. They are now explicitly listed as the
48 # ---------------------------------------------------------------------------
50 # Normally, we echo the whole command before executing it. By making
51 # that echo $($(quiet)$(cmd)), we now have the possibility to set
52 # $(quiet) to choose other forms of output instead, e.g.
54 # quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
55 # cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
57 # If $(quiet) is empty, the whole command will be printed.
58 # If it is set to "quiet_", only the short version will be printed.
59 # If it is set to "silent_", nothing will be printed at all, since
60 # the variable $(silent_cmd_cc_o_c) doesn't exist.
62 # A simple variant is to prefix commands with $(Q) - that's useful
63 # for commands that shall be hidden in non-verbose mode.
67 # If KBUILD_VERBOSE equals 0 then the above command will be hidden.
68 # If KBUILD_VERBOSE equals 1 then the above command is displayed.
70 # To put more focus on warnings, be less verbose as default
71 # Use 'make V=1' to see the full commands
73 ifeq ("$(origin V)", "command line")
80 ifeq ($(KBUILD_VERBOSE),1)
88 # If the user is running make -s (silent mode), suppress echoing of
91 ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
96 export quiet Q KBUILD_VERBOSE
98 # kbuild supports saving output files in a separate directory.
99 # To locate output files in a separate directory two syntaxes are supported.
100 # In both cases the working directory must be the root of the kernel src.
102 # Use "make O=dir/to/store/output/files/"
104 # 2) Set KBUILD_OUTPUT
105 # Set the environment variable KBUILD_OUTPUT to point to the directory
106 # where the output files shall be placed.
107 # export KBUILD_OUTPUT=dir/to/store/output/files/
110 # The O= assignment takes precedence over the KBUILD_OUTPUT environment
113 # KBUILD_SRC is not intended to be used by the regular user (for now),
114 # it is set on invocation of make with KBUILD_OUTPUT or O= specified.
115 ifeq ($(KBUILD_SRC),)
117 # OK, Make called in directory where kernel src resides
118 # Do we want to locate output files in a separate directory?
119 ifeq ("$(origin O)", "command line")
120 KBUILD_OUTPUT := $(O)
123 # Cancel implicit rules on top Makefile
124 $(CURDIR)/Makefile Makefile: ;
126 ifneq ($(words $(subst :, ,$(CURDIR))), 1)
127 $(error main directory cannot contain spaces nor colons)
130 ifneq ($(KBUILD_OUTPUT),)
131 # check that the output directory actually exists
132 saved-output := $(KBUILD_OUTPUT)
133 KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
135 $(if $(KBUILD_OUTPUT),, \
136 $(error failed to create output directory "$(saved-output)"))
138 # Look for make include files relative to root of kernel src
140 # This does not become effective immediately because MAKEFLAGS is re-parsed
141 # once after the Makefile is read. It is OK since we are going to invoke
143 MAKEFLAGS += --include-dir=$(CURDIR)
145 PHONY += $(MAKECMDGOALS) sub-make
147 $(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
150 # Invoke a second make in the output directory, passing relevant variables
152 $(Q)$(MAKE) -C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR) \
153 -f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS))
155 # Leave processing to above invocation of make
157 endif # ifneq ($(KBUILD_OUTPUT),)
158 endif # ifeq ($(KBUILD_SRC),)
160 # We process the rest of the Makefile if this is the final invocation of make
161 ifeq ($(skip-makefile),)
163 # Do not print "Entering directory ...",
164 # but we want to display it when entering to the output directory
165 # so that IDEs/editors are able to understand relative filenames.
166 MAKEFLAGS += --no-print-directory
168 # Call a source code checker (by default, "sparse") as part of the
171 # Use 'make C=1' to enable checking of only re-compiled files.
172 # Use 'make C=2' to enable checking of *all* source files, regardless
173 # of whether they are re-compiled or not.
175 # See the file "Documentation/dev-tools/sparse.rst" for more details,
176 # including where to get the "sparse" utility.
178 ifeq ("$(origin C)", "command line")
179 KBUILD_CHECKSRC = $(C)
181 ifndef KBUILD_CHECKSRC
185 # Use make M=dir to specify directory of external module to build
186 # Old syntax make ... SUBDIRS=$PWD is still supported
187 # Setting the environment variable KBUILD_EXTMOD take precedence
189 $(warning ================= WARNING ================)
190 $(warning 'SUBDIRS' will be removed after Linux 5.3)
191 $(warning Please use 'M=' or 'KBUILD_EXTMOD' instead)
192 $(warning ==========================================)
193 KBUILD_EXTMOD ?= $(SUBDIRS)
196 ifeq ("$(origin M)", "command line")
197 KBUILD_EXTMOD := $(M)
200 ifeq ($(KBUILD_SRC),)
201 # building in the source tree
204 ifeq ($(KBUILD_SRC)/,$(dir $(CURDIR)))
205 # building in a subdirectory of the source tree
208 srctree := $(KBUILD_SRC)
212 export KBUILD_CHECKSRC KBUILD_EXTMOD KBUILD_SRC
218 VPATH := $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))
220 export srctree objtree VPATH
222 # To make sure we do not include .config for any of the *config targets
223 # catch them early, and hand them over to scripts/kconfig/Makefile
224 # It is allowed to specify more targets when calling make, including
225 # mixing *config targets and build targets.
226 # For example 'make oldconfig all'.
227 # Detect when mixed targets is specified, and make a second invocation
228 # of make so .config is not included in this case either (for *config).
230 version_h := include/generated/uapi/linux/version.h
231 old_version_h := include/linux/version.h
233 clean-targets := %clean mrproper cleandocs
234 no-dot-config-targets := $(clean-targets) \
235 cscope gtags TAGS tags help% %docs check% coccicheck \
236 $(version_h) headers_% archheaders archscripts \
237 %asm-generic kernelversion %src-pkg
238 no-sync-config-targets := $(no-dot-config-targets) install %install \
246 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
247 ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
252 ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
253 ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
258 ifneq ($(KBUILD_EXTMOD),)
262 ifeq ($(KBUILD_EXTMOD),)
263 ifneq ($(filter config %config,$(MAKECMDGOALS)),)
265 ifneq ($(words $(MAKECMDGOALS)),1)
271 # For "make -j clean all", "make -j mrproper defconfig all", etc.
272 ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
273 ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
278 # install and modules_install need also be processed one by one
279 ifneq ($(filter install,$(MAKECMDGOALS)),)
280 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
285 ifeq ($(mixed-targets),1)
286 # ===========================================================================
287 # We're called with mixed targets (*config and build targets).
288 # Handle them one by one.
290 PHONY += $(MAKECMDGOALS) __build_one_by_one
292 $(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
297 for i in $(MAKECMDGOALS); do \
298 $(MAKE) -f $(srctree)/Makefile $$i; \
303 # We need some generic definitions (do not try to remake the file).
304 scripts/Kbuild.include: ;
305 include scripts/Kbuild.include
307 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
308 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
309 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
310 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
312 include scripts/subarch.include
314 # Cross compiling and selecting different set of gcc/bin-utils
315 # ---------------------------------------------------------------------------
317 # When performing cross compilation for other architectures ARCH shall be set
318 # to the target architecture. (See arch/* for the possibilities).
319 # ARCH can be set during invocation of make:
321 # Another way is to have ARCH set in the environment.
322 # The default ARCH is the host where make is executed.
324 # CROSS_COMPILE specify the prefix used for all executables used
325 # during compilation. Only gcc and related bin-utils executables
326 # are prefixed with $(CROSS_COMPILE).
327 # CROSS_COMPILE can be set on the command line
328 # make CROSS_COMPILE=ia64-linux-
329 # Alternatively CROSS_COMPILE can be set in the environment.
330 # Default value for CROSS_COMPILE is not to prefix executables
331 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
334 # Architecture as present in compile.h
335 UTS_MACHINE := $(ARCH)
338 # Additional ARCH settings for x86
342 ifeq ($(ARCH),x86_64)
346 # Additional ARCH settings for sparc
347 ifeq ($(ARCH),sparc32)
350 ifeq ($(ARCH),sparc64)
354 # Additional ARCH settings for sh
359 KCONFIG_CONFIG ?= .config
360 export KCONFIG_CONFIG
362 # SHELL used by kbuild
363 CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
364 else if [ -x /bin/bash ]; then echo /bin/bash; \
365 else echo sh; fi ; fi)
367 HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
368 HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
369 HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
373 KBUILD_HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 \
374 -fomit-frame-pointer -std=gnu89 $(HOST_LFS_CFLAGS) \
376 KBUILD_HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
377 KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
378 KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
380 # Make variables (CC, etc...)
381 AS = $(CROSS_COMPILE)as
382 LD = $(CROSS_COMPILE)ld
383 CC = $(CROSS_COMPILE)gcc
385 AR = $(CROSS_COMPILE)ar
386 NM = $(CROSS_COMPILE)nm
387 STRIP = $(CROSS_COMPILE)strip
388 OBJCOPY = $(CROSS_COMPILE)objcopy
389 OBJDUMP = $(CROSS_COMPILE)objdump
393 GENKSYMS = scripts/genksyms/genksyms
394 INSTALLKERNEL := installkernel
395 DEPMOD = /sbin/depmod
402 CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
403 -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
412 # Use USERINCLUDE when you must reference the UAPI directories only.
414 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
415 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
416 -I$(srctree)/include/uapi \
417 -I$(objtree)/include/generated/uapi \
418 -include $(srctree)/include/linux/kconfig.h
420 # Use LINUXINCLUDE when you must reference the include/ directory.
421 # Needed to be compatible with the O= option
423 -I$(srctree)/arch/$(SRCARCH)/include \
424 -I$(objtree)/arch/$(SRCARCH)/include/generated \
425 $(if $(KBUILD_SRC), -I$(srctree)/include) \
426 -I$(objtree)/include \
429 KBUILD_AFLAGS := -D__ASSEMBLY__ -fno-PIE
430 KBUILD_CFLAGS := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
431 -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
432 -Werror-implicit-function-declaration -Werror=implicit-int \
433 -Wno-format-security \
435 KBUILD_CPPFLAGS := -D__KERNEL__
436 KBUILD_AFLAGS_KERNEL :=
437 KBUILD_CFLAGS_KERNEL :=
438 KBUILD_AFLAGS_MODULE := -DMODULE
439 KBUILD_CFLAGS_MODULE := -DMODULE
440 KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
442 GCC_PLUGINS_CFLAGS :=
444 export ARCH SRCARCH CONFIG_SHELL HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE AS LD CC
445 export CPP AR NM STRIP OBJCOPY OBJDUMP KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS
446 export MAKE LEX YACC AWK GENKSYMS INSTALLKERNEL PERL PYTHON PYTHON2 PYTHON3 UTS_MACHINE
447 export HOSTCXX KBUILD_HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
449 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
450 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
451 export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN
452 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
453 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
454 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
455 export KBUILD_ARFLAGS
457 # When compiling out-of-tree modules, put MODVERDIR in the module
458 # tree rather than in the kernel tree. The kernel tree might
460 export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
462 # Files to ignore in find ... statements
464 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
465 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
467 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
468 --exclude CVS --exclude .pc --exclude .hg --exclude .git
470 # ===========================================================================
471 # Rules shared between *config targets and build targets
473 # Basic helpers built in scripts/basic/
474 PHONY += scripts_basic
476 $(Q)$(MAKE) $(build)=scripts/basic
477 $(Q)rm -f .tmp_quiet_recordmcount
479 # To avoid any implicit rule to kick in, define an empty command.
480 scripts/basic/%: scripts_basic ;
482 PHONY += outputmakefile
483 # outputmakefile generates a Makefile in the output directory, if using a
484 # separate output directory. This allows convenient use of make in the
487 ifneq ($(KBUILD_SRC),)
488 $(Q)ln -fsn $(srctree) source
489 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
492 ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
493 ifneq ($(CROSS_COMPILE),)
494 CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE:%-=%))
495 GCC_TOOLCHAIN_DIR := $(dir $(shell which $(LD)))
496 CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)
497 GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..)
499 ifneq ($(GCC_TOOLCHAIN),)
500 CLANG_FLAGS += --gcc-toolchain=$(GCC_TOOLCHAIN)
502 CLANG_FLAGS += -no-integrated-as
503 KBUILD_CFLAGS += $(CLANG_FLAGS)
504 KBUILD_AFLAGS += $(CLANG_FLAGS)
508 RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
509 RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
510 RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
511 RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
512 RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
513 RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
514 export RETPOLINE_CFLAGS
515 export RETPOLINE_VDSO_CFLAGS
517 # check for 'asm goto'
518 ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y)
519 CC_HAVE_ASM_GOTO := 1
520 KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
521 KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO
524 # The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
525 # Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
526 # CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
527 # and from include/config/auto.conf.cmd to detect the compiler upgrade.
528 CC_VERSION_TEXT = $(shell $(CC) --version | head -n 1)
530 ifeq ($(config-targets),1)
531 # ===========================================================================
532 # *config targets only - make sure prerequisites are updated, and descend
533 # in scripts/kconfig to make the *config target
535 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
536 # KBUILD_DEFCONFIG may point out an alternative default configuration
537 # used for 'make defconfig'
538 include arch/$(SRCARCH)/Makefile
539 export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
541 config: scripts_basic outputmakefile FORCE
542 $(Q)$(MAKE) $(build)=scripts/kconfig $@
544 %config: scripts_basic outputmakefile FORCE
545 $(Q)$(MAKE) $(build)=scripts/kconfig $@
548 # ===========================================================================
549 # Build targets only - this includes vmlinux, arch specific targets, clean
550 # targets and others. In general all targets except *config targets.
552 # If building an external module we do not care about the all: rule
553 # but instead _all depend on modules
555 ifeq ($(KBUILD_EXTMOD),)
561 # Decide whether to build built-in, modular, or both.
562 # Normally, just do built-in.
567 # If we have only "make modules", don't compile built-in objects.
568 # When we're building modules with modversions, we need to consider
569 # the built-in objects during the descend as well, in order to
570 # make sure the checksums are up to date before we record them.
572 ifeq ($(MAKECMDGOALS),modules)
573 KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
576 # If we have "make <whatever> modules", compile modules
577 # in addition to whatever we do anyway.
578 # Just "make" or "make all" shall build modules as well
580 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
584 ifeq ($(MAKECMDGOALS),)
588 export KBUILD_MODULES KBUILD_BUILTIN
590 ifeq ($(KBUILD_EXTMOD),)
591 # Objects we will link into vmlinux / subdirs we need to visit
593 drivers-y := drivers/ sound/ firmware/
598 endif # KBUILD_EXTMOD
600 ifeq ($(dot-config),1)
601 include include/config/auto.conf
604 # The all: target is the default when no target is given on the
606 # This allow a user to issue only 'make' to build a kernel including modules
607 # Defaults to vmlinux, but the arch makefile usually adds further targets
610 CFLAGS_GCOV := -fprofile-arcs -ftest-coverage \
611 $(call cc-option,-fno-tree-loop-im) \
612 $(call cc-disable-warning,maybe-uninitialized,)
615 # The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
616 ifdef CONFIG_FUNCTION_TRACER
617 CC_FLAGS_FTRACE := -pg
620 # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
621 # values of the respective KBUILD_* variables
625 include arch/$(SRCARCH)/Makefile
627 ifeq ($(dot-config),1)
628 ifeq ($(may-sync-config),1)
629 # Read in dependencies to all Kconfig* files, make sure to run syncconfig if
630 # changes are detected. This should be included after arch/$(SRCARCH)/Makefile
631 # because some architectures define CROSS_COMPILE there.
632 -include include/config/auto.conf.cmd
634 # To avoid any implicit rule to kick in, define an empty command
635 $(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;
637 # The actual configuration files used during the build are stored in
638 # include/generated/ and include/config/. Update them if .config is newer than
639 # include/config/auto.conf (which mirrors .config).
640 include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
641 $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
643 # External modules and some install targets need include/generated/autoconf.h
644 # and include/config/auto.conf but do not care if they are up-to-date.
645 # Use auto.conf to trigger the test
646 PHONY += include/config/auto.conf
648 include/config/auto.conf:
649 $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
651 echo >&2 " ERROR: Kernel configuration is invalid."; \
652 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
653 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
657 endif # may-sync-config
658 endif # $(dot-config)
660 KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
661 KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
662 KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
663 KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
664 KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context)
666 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
667 KBUILD_CFLAGS += $(call cc-option,-Oz,-Os)
668 KBUILD_CFLAGS += $(call cc-disable-warning,maybe-uninitialized,)
670 ifdef CONFIG_PROFILE_ALL_BRANCHES
671 KBUILD_CFLAGS += -O2 $(call cc-disable-warning,maybe-uninitialized,)
677 KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \
678 $(call cc-disable-warning,maybe-uninitialized,))
680 # Tell gcc to never replace conditional load with a non-conditional one
681 KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
683 include scripts/Makefile.kcov
684 include scripts/Makefile.gcc-plugins
686 ifdef CONFIG_READABLE_ASM
687 # Disable optimizations that make assembler listings hard to read.
688 # reorder blocks reorders the control in the function
689 # ipa clone creates specialized cloned functions
690 # partial inlining inlines only parts of functions
691 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
692 $(call cc-option,-fno-ipa-cp-clone,) \
693 $(call cc-option,-fno-partial-inlining)
696 ifneq ($(CONFIG_FRAME_WARN),0)
697 KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
700 stackp-flags-$(CONFIG_CC_HAS_STACKPROTECTOR_NONE) := -fno-stack-protector
701 stackp-flags-$(CONFIG_STACKPROTECTOR) := -fstack-protector
702 stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong
704 KBUILD_CFLAGS += $(stackp-flags-y)
706 ifdef CONFIG_CC_IS_CLANG
707 KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
708 KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
709 KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
710 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
711 # Quiet clang warning: comparison of unsigned expression < 0 is always false
712 KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
713 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
714 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
715 # See modpost pattern 2
716 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
717 KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
720 # These warnings generated too much noise in a regular build.
721 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
722 KBUILD_CFLAGS += -Wno-unused-but-set-variable
725 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
726 ifdef CONFIG_FRAME_POINTER
727 KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
729 # Some targets (ARM with Thumb2, for example), can't be built with frame
730 # pointers. For those, we don't have FUNCTION_TRACER automatically
731 # select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
732 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
733 # -fomit-frame-pointer with FUNCTION_TRACER.
734 ifndef CONFIG_FUNCTION_TRACER
735 KBUILD_CFLAGS += -fomit-frame-pointer
739 KBUILD_CFLAGS += $(call cc-option, -fno-var-tracking-assignments)
741 ifdef CONFIG_DEBUG_INFO
742 ifdef CONFIG_DEBUG_INFO_SPLIT
743 KBUILD_CFLAGS += $(call cc-option, -gsplit-dwarf, -g)
747 KBUILD_AFLAGS += -Wa,-gdwarf-2
749 ifdef CONFIG_DEBUG_INFO_DWARF4
750 KBUILD_CFLAGS += $(call cc-option, -gdwarf-4,)
753 ifdef CONFIG_DEBUG_INFO_REDUCED
754 KBUILD_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
755 $(call cc-option,-fno-var-tracking)
758 ifdef CONFIG_FUNCTION_TRACER
759 ifdef CONFIG_FTRACE_MCOUNT_RECORD
760 # gcc 5 supports generating the mcount tables directly
761 ifeq ($(call cc-option-yn,-mrecord-mcount),y)
762 CC_FLAGS_FTRACE += -mrecord-mcount
763 export CC_USING_RECORD_MCOUNT := 1
765 ifdef CONFIG_HAVE_NOP_MCOUNT
766 ifeq ($(call cc-option-yn, -mnop-mcount),y)
767 CC_FLAGS_FTRACE += -mnop-mcount
768 CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
772 ifdef CONFIG_HAVE_FENTRY
773 ifeq ($(call cc-option-yn, -mfentry),y)
774 CC_FLAGS_FTRACE += -mfentry
775 CC_FLAGS_USING += -DCC_USING_FENTRY
778 export CC_FLAGS_FTRACE
779 KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
780 KBUILD_AFLAGS += $(CC_FLAGS_USING)
781 ifdef CONFIG_DYNAMIC_FTRACE
782 ifdef CONFIG_HAVE_C_RECORDMCOUNT
783 BUILD_C_RECORDMCOUNT := y
784 export BUILD_C_RECORDMCOUNT
789 # We trigger additional mismatches with less inlining
790 ifdef CONFIG_DEBUG_SECTION_MISMATCH
791 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
794 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
795 KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
796 LDFLAGS_vmlinux += --gc-sections
799 ifdef CONFIG_LIVEPATCH
800 KBUILD_CFLAGS += $(call cc-option, -flive-patching=inline-clone)
803 # arch Makefile may override CC so keep this after arch Makefile is included
804 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
806 # warn about C99 declaration after statement
807 KBUILD_CFLAGS += -Wdeclaration-after-statement
809 # Variable Length Arrays (VLAs) should not be used anywhere in the kernel
810 KBUILD_CFLAGS += $(call cc-option,-Wvla)
812 # disable pointer signed / unsigned warnings in gcc 4.0
813 KBUILD_CFLAGS += -Wno-pointer-sign
815 # disable stringop warnings in gcc 8+
816 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
818 # disable invalid "can't wrap" optimizations for signed / pointers
819 KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
821 # clang sets -fmerge-all-constants by default as optimization, but this
822 # is non-conforming behavior for C and in fact breaks the kernel, so we
823 # need to disable it here generally.
824 KBUILD_CFLAGS += $(call cc-option,-fno-merge-all-constants)
826 # for gcc -fno-merge-all-constants disables everything, but it is fine
827 # to have actual conforming behavior enabled.
828 KBUILD_CFLAGS += $(call cc-option,-fmerge-constants)
830 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
831 KBUILD_CFLAGS += $(call cc-option,-fno-stack-check,)
833 # conserve stack if available
834 KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
836 # Prohibit date/time macros, which would make the build non-deterministic
837 KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
839 # enforce correct pointer usage
840 KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
842 # Require designated initializers for all marked structures
843 KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
845 # change __FILE__ to the relative path from the srctree
846 KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
848 # use the deterministic mode of AR if available
849 KBUILD_ARFLAGS := $(call ar-option,D)
851 include scripts/Makefile.kasan
852 include scripts/Makefile.extrawarn
853 include scripts/Makefile.ubsan
855 # Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
857 KBUILD_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS)
858 KBUILD_AFLAGS += $(ARCH_AFLAGS) $(KAFLAGS)
859 KBUILD_CFLAGS += $(ARCH_CFLAGS) $(KCFLAGS)
861 # Use --build-id when available.
862 LDFLAGS_BUILD_ID := $(call ld-option, --build-id)
863 KBUILD_LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
864 LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
866 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
867 LDFLAGS_vmlinux += $(call ld-option, -X,)
870 # insure the checker run with the right endianness
871 CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
873 # the checker needs the correct machine size
874 CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
876 # Default kernel image to build when no specific target is given.
877 # KBUILD_IMAGE may be overruled on the command line or
878 # set in the environment
879 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
881 export KBUILD_IMAGE ?= vmlinux
884 # INSTALL_PATH specifies where to place the updated kernel and system map
885 # images. Default is /boot, but you can set it to other values
886 export INSTALL_PATH ?= /boot
889 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
890 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
891 # an argument if needed. Otherwise it defaults to the kernel install path
893 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
896 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
897 # relocations required by build roots. This is not defined in the
898 # makefile but the argument can be passed to make if needed.
901 MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
905 # INSTALL_MOD_STRIP, if defined, will cause modules to be
906 # stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
907 # the default option --strip-debug will be used. Otherwise,
908 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
910 ifdef INSTALL_MOD_STRIP
911 ifeq ($(INSTALL_MOD_STRIP),1)
912 mod_strip_cmd = $(STRIP) --strip-debug
914 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
915 endif # INSTALL_MOD_STRIP=1
918 endif # INSTALL_MOD_STRIP
921 # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
922 # after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
923 # or CONFIG_MODULE_COMPRESS_XZ.
925 mod_compress_cmd = true
926 ifdef CONFIG_MODULE_COMPRESS
927 ifdef CONFIG_MODULE_COMPRESS_GZIP
928 mod_compress_cmd = gzip -n -f
929 endif # CONFIG_MODULE_COMPRESS_GZIP
930 ifdef CONFIG_MODULE_COMPRESS_XZ
931 mod_compress_cmd = xz -f
932 endif # CONFIG_MODULE_COMPRESS_XZ
933 endif # CONFIG_MODULE_COMPRESS
934 export mod_compress_cmd
936 # Select initial ramdisk compression format, default is gzip(1).
937 # This shall be used by the dracut(8) tool while creating an initramfs image.
939 INITRD_COMPRESS-y := gzip
940 INITRD_COMPRESS-$(CONFIG_RD_BZIP2) := bzip2
941 INITRD_COMPRESS-$(CONFIG_RD_LZMA) := lzma
942 INITRD_COMPRESS-$(CONFIG_RD_XZ) := xz
943 INITRD_COMPRESS-$(CONFIG_RD_LZO) := lzo
944 INITRD_COMPRESS-$(CONFIG_RD_LZ4) := lz4
945 # do not export INITRD_COMPRESS, since we didn't actually
946 # choose a sane default compression above.
947 # export INITRD_COMPRESS := $(INITRD_COMPRESS-y)
949 ifdef CONFIG_MODULE_SIG_ALL
950 $(eval $(call config_filename,MODULE_SIG_KEY))
952 mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
958 ifdef CONFIG_STACK_VALIDATION
959 has_libelf := $(call try-run,\
960 echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0)
961 ifeq ($(has_libelf),1)
962 objtool_target := tools/objtool FORCE
964 SKIP_STACK_VALIDATION := 1
965 export SKIP_STACK_VALIDATION
970 ifeq ($(KBUILD_EXTMOD),)
971 core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
973 vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
974 $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
975 $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
977 vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
978 $(init-) $(core-) $(drivers-) $(net-) $(libs-) $(virt-))))
980 init-y := $(patsubst %/, %/built-in.a, $(init-y))
981 core-y := $(patsubst %/, %/built-in.a, $(core-y))
982 drivers-y := $(patsubst %/, %/built-in.a, $(drivers-y))
983 net-y := $(patsubst %/, %/built-in.a, $(net-y))
984 libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
985 libs-y2 := $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y)))
986 virt-y := $(patsubst %/, %/built-in.a, $(virt-y))
988 # Externally visible symbols (used by link-vmlinux.sh)
989 export KBUILD_VMLINUX_INIT := $(head-y) $(init-y)
990 export KBUILD_VMLINUX_MAIN := $(core-y) $(libs-y2) $(drivers-y) $(net-y) $(virt-y)
991 export KBUILD_VMLINUX_LIBS := $(libs-y1)
992 export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
993 export LDFLAGS_vmlinux
994 # used by scripts/package/Makefile
995 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools)
997 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_INIT) $(KBUILD_VMLINUX_MAIN) $(KBUILD_VMLINUX_LIBS)
999 # Recurse until adjust_autoksyms.sh is satisfied
1000 PHONY += autoksyms_recursive
1001 autoksyms_recursive: $(vmlinux-deps)
1002 ifdef CONFIG_TRIM_UNUSED_KSYMS
1003 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1004 "$(MAKE) -f $(srctree)/Makefile vmlinux"
1007 # For the kernel to actually contain only the needed exported symbols,
1008 # we have to build modules as well to determine what those symbols are.
1009 # (this can be evaluated only once include/config/auto.conf has been included)
1010 ifdef CONFIG_TRIM_UNUSED_KSYMS
1014 autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1017 $(Q)mkdir -p $(dir $@)
1020 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1022 # Final link of vmlinux with optional arch pass after final link
1023 cmd_link-vmlinux = \
1024 $(CONFIG_SHELL) $< $(LD) $(KBUILD_LDFLAGS) $(LDFLAGS_vmlinux) ; \
1025 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1027 vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1028 ifdef CONFIG_GDB_SCRIPTS
1029 $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1031 +$(call if_changed,link-vmlinux)
1035 # Build samples along the rest of the kernel. This needs headers_install.
1036 ifdef CONFIG_SAMPLES
1037 vmlinux-dirs += samples
1038 samples: headers_install
1041 # The actual objects are generated when descending,
1042 # make sure no implicit rule kicks in
1043 $(sort $(vmlinux-deps)): $(vmlinux-dirs) ;
1045 # Handle descending into subdirectories listed in $(vmlinux-dirs)
1046 # Preset locale variables to speed up the build process. Limit locale
1047 # tweaks to this spot to avoid wrong language settings when running
1048 # make menuconfig etc.
1049 # Error messages still appears in the original language
1051 PHONY += $(vmlinux-dirs)
1052 $(vmlinux-dirs): prepare
1053 $(Q)$(MAKE) $(build)=$@ need-builtin=1
1055 define filechk_kernel.release
1056 echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1059 # Store (new) KERNELRELEASE string in include/config/kernel.release
1060 include/config/kernel.release: $(srctree)/Makefile FORCE
1061 $(call filechk,kernel.release)
1063 # Additional helpers built in scripts/
1064 # Carefully list dependencies so we do not try to build scripts twice
1067 scripts: scripts_basic scripts_dtc
1068 $(Q)$(MAKE) $(build)=$(@)
1070 # Things we need to do before we recursively start building the kernel
1071 # or the modules are listed in "prepare".
1072 # A multi level approach is used. prepareN is processed before prepareN-1.
1073 # archprepare is used in arch Makefiles and when processed asm symlink,
1074 # version.h and scripts_basic is processed / created.
1076 # Listed in dependency order
1077 PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3
1079 # prepare3 is used to check if we are building in a separate output directory,
1081 # 1) Check that make has not been executed in the kernel src $(srctree)
1082 prepare3: include/config/kernel.release
1083 ifneq ($(KBUILD_SRC),)
1084 @$(kecho) ' Using $(srctree) as source for kernel'
1085 $(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
1086 echo >&2 " $(srctree) is not clean, please run 'make mrproper'"; \
1087 echo >&2 " in the '$(srctree)' directory.";\
1092 # prepare2 creates a makefile if using a separate output directory.
1093 # From this point forward, .config has been reprocessed, so any rules
1094 # that need to depend on updated CONFIG_* values can be checked here.
1095 prepare2: prepare3 outputmakefile asm-generic
1097 prepare1: prepare2 $(version_h) $(autoksyms_h) include/generated/utsrelease.h
1100 archprepare: archheaders archscripts prepare1 scripts
1102 prepare0: archprepare
1103 $(Q)$(MAKE) $(build)=scripts/mod
1104 $(Q)$(MAKE) $(build)=.
1106 # All the preparing..
1107 prepare: prepare0 prepare-objtool
1109 # Support for using generic headers in asm-generic
1110 asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1112 PHONY += asm-generic uapi-asm-generic
1113 asm-generic: uapi-asm-generic
1114 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm
1116 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm
1118 PHONY += prepare-objtool
1119 prepare-objtool: $(objtool_target)
1120 ifeq ($(SKIP_STACK_VALIDATION),1)
1121 ifdef CONFIG_UNWINDER_ORC
1122 @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1125 @echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1129 # Generate some files
1130 # ---------------------------------------------------------------------------
1132 # KERNELRELEASE can change from a few different places, meaning version.h
1133 # needs to be updated, so this check is forced on all builds
1136 define filechk_utsrelease.h
1137 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1138 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1141 (echo \#define UTS_RELEASE \"$(KERNELRELEASE)\";)
1144 define filechk_version.h
1145 (echo \#define LINUX_VERSION_CODE $(shell \
1146 expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
1147 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))';)
1151 $(call filechk,version.h)
1152 $(Q)rm -f $(old_version_h)
1154 include/generated/utsrelease.h: include/config/kernel.release FORCE
1155 $(call filechk,utsrelease.h)
1159 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1160 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1162 # ---------------------------------------------------------------------------
1165 #Default location for installed headers
1166 export INSTALL_HDR_PATH = $(objtree)/usr
1168 # If we do an all arch process set dst to include/arch-$(SRCARCH)
1169 hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(SRCARCH), dst=include)
1171 PHONY += archheaders
1174 PHONY += archscripts
1178 __headers: $(version_h) scripts_basic uapi-asm-generic archheaders archscripts
1179 $(Q)$(MAKE) $(build)=scripts build_unifdef
1181 PHONY += headers_install_all
1182 headers_install_all:
1183 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh install
1185 PHONY += headers_install
1186 headers_install: __headers
1187 $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1188 $(error Headers not exportable for the $(SRCARCH) architecture))
1189 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include
1190 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst)
1192 PHONY += headers_check_all
1193 headers_check_all: headers_install_all
1194 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh check
1196 PHONY += headers_check
1197 headers_check: headers_install
1198 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include HDRCHECK=1
1199 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst) HDRCHECK=1
1201 ifdef CONFIG_HEADERS_CHECK
1205 # ---------------------------------------------------------------------------
1210 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1212 PHONY += kselftest-clean
1214 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests clean
1216 PHONY += kselftest-merge
1218 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1219 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \
1220 -m $(objtree)/.config \
1221 $(srctree)/tools/testing/selftests/*/config
1222 +$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1224 # ---------------------------------------------------------------------------
1227 ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1228 dtstree := arch/$(SRCARCH)/boot/dts
1233 %.dtb: prepare3 scripts_dtc
1234 $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1236 PHONY += dtbs dtbs_install dt_binding_check
1237 dtbs dtbs_check: prepare3 scripts_dtc
1238 $(Q)$(MAKE) $(build)=$(dtstree)
1240 dtbs_check: export CHECK_DTBS=1
1241 dtbs_check: dt_binding_check
1244 $(Q)$(MAKE) $(dtbinst)=$(dtstree)
1246 ifdef CONFIG_OF_EARLY_FLATTREE
1252 PHONY += scripts_dtc
1253 scripts_dtc: scripts_basic
1254 $(Q)$(MAKE) $(build)=scripts/dtc
1256 dt_binding_check: scripts_dtc
1257 $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1259 # ---------------------------------------------------------------------------
1262 ifdef CONFIG_MODULES
1264 # By default, build modules as well
1270 # A module can be listed more than once in obj-m resulting in
1271 # duplicate lines in modules.order files. Those are removed
1272 # using awk while concatenating to the final file.
1275 modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
1276 $(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
1277 @$(kecho) ' Building modules, stage 2.';
1278 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1280 modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
1281 $(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
1283 %/modules.builtin: include/config/auto.conf include/config/tristate.conf
1284 $(Q)$(MAKE) $(modbuiltin)=$*
1287 # Target to prepare building external modules
1288 PHONY += modules_prepare
1289 modules_prepare: prepare
1291 # Target to install modules
1292 PHONY += modules_install
1293 modules_install: _modinst_ _modinst_post
1297 @rm -rf $(MODLIB)/kernel
1298 @rm -f $(MODLIB)/source
1299 @mkdir -p $(MODLIB)/kernel
1300 @ln -s $(abspath $(srctree)) $(MODLIB)/source
1301 @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
1302 rm -f $(MODLIB)/build ; \
1303 ln -s $(CURDIR) $(MODLIB)/build ; \
1305 @cp -f $(objtree)/modules.order $(MODLIB)/
1306 @cp -f $(objtree)/modules.builtin $(MODLIB)/
1307 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1309 # This depmod is only for convenience to give the initial
1310 # boot a modules.dep even before / is mounted read-write. However the
1311 # boot script depmod is the master version.
1312 PHONY += _modinst_post
1313 _modinst_post: _modinst_
1316 ifeq ($(CONFIG_MODULE_SIG), y)
1317 PHONY += modules_sign
1319 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1322 else # CONFIG_MODULES
1324 # Modules not configured
1325 # ---------------------------------------------------------------------------
1327 PHONY += modules modules_install
1328 modules modules_install:
1330 @echo >&2 "The present kernel configuration has modules disabled."
1331 @echo >&2 "Type 'make config' and enable loadable module support."
1332 @echo >&2 "Then build a kernel with module support enabled."
1336 endif # CONFIG_MODULES
1339 # Cleaning is done on three levels.
1340 # make clean Delete most generated files
1341 # Leave enough to build external modules
1342 # make mrproper Delete the current configuration, and all generated files
1343 # make distclean Remove editor backup files, patch leftover files and the like
1345 # Directories & files removed with 'make clean'
1346 CLEAN_DIRS += $(MODVERDIR) include/ksym
1348 # Directories & files removed with 'make mrproper'
1349 MRPROPER_DIRS += include/config usr/include include/generated \
1350 arch/*/include/generated .tmp_objdiff
1351 MRPROPER_FILES += .config .config.old .version \
1352 Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
1353 signing_key.pem signing_key.priv signing_key.x509 \
1354 x509.genkey extra_certificates signing_key.x509.keyid \
1355 signing_key.x509.signer vmlinux-gdb.py
1357 # clean - Delete most, but leave enough to build external modules
1359 clean: rm-dirs := $(CLEAN_DIRS)
1360 clean: rm-files := $(CLEAN_FILES)
1361 clean-dirs := $(addprefix _clean_, . $(vmlinux-alldirs) Documentation samples)
1363 PHONY += $(clean-dirs) clean archclean vmlinuxclean
1365 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1368 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1369 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1371 clean: archclean vmlinuxclean
1373 # mrproper - Delete all generated files, including .config
1375 mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS))
1376 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1377 mrproper-dirs := $(addprefix _mrproper_,scripts)
1379 PHONY += $(mrproper-dirs) mrproper archmrproper
1381 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1383 mrproper: clean archmrproper $(mrproper-dirs)
1392 @find $(srctree) $(RCS_FIND_IGNORE) \
1393 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1394 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1395 -o -name 'core' \) \
1396 -type f -print | xargs rm -f
1399 # Packaging of the kernel to various formats
1400 # ---------------------------------------------------------------------------
1401 package-dir := scripts/package
1404 $(Q)$(MAKE) $(build)=$(package-dir) $@
1405 %pkg: include/config/kernel.release FORCE
1406 $(Q)$(MAKE) $(build)=$(package-dir) $@
1409 # Brief documentation of the typical targets used
1410 # ---------------------------------------------------------------------------
1412 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1413 boards := $(sort $(notdir $(boards)))
1414 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1415 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1419 @echo 'Cleaning targets:'
1420 @echo ' clean - Remove most generated files but keep the config and'
1421 @echo ' enough build support to build external modules'
1422 @echo ' mrproper - Remove all generated files + config + various backup files'
1423 @echo ' distclean - mrproper + remove editor backup and patch files'
1425 @echo 'Configuration targets:'
1426 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1428 @echo 'Other generic targets:'
1429 @echo ' all - Build all targets marked with [*]'
1430 @echo '* vmlinux - Build the bare kernel'
1431 @echo '* modules - Build all modules'
1432 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1433 @echo ' dir/ - Build all files in dir and below'
1434 @echo ' dir/file.[ois] - Build specified target only'
1435 @echo ' dir/file.ll - Build the LLVM assembly file'
1436 @echo ' (requires compiler support for LLVM assembly generation)'
1437 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1438 @echo ' (requires a recent binutils and recent build (System.map))'
1439 @echo ' dir/file.ko - Build module including final link'
1440 @echo ' modules_prepare - Set up for building external modules'
1441 @echo ' tags/TAGS - Generate tags file for editors'
1442 @echo ' cscope - Generate cscope index'
1443 @echo ' gtags - Generate GNU GLOBAL index'
1444 @echo ' kernelrelease - Output the release version string (use with make -s)'
1445 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1446 @echo ' image_name - Output the image name (use with make -s)'
1447 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1448 echo ' (default: $(INSTALL_HDR_PATH))'; \
1450 @echo 'Static analysers:'
1451 @echo ' checkstack - Generate a list of stack hogs'
1452 @echo ' namespacecheck - Name space analysis on compiled kernel'
1453 @echo ' versioncheck - Sanity check on version.h usage'
1454 @echo ' includecheck - Check for duplicate included header files'
1455 @echo ' export_report - List the usages of all exported symbols'
1456 @echo ' headers_check - Sanity check on exported headers'
1457 @echo ' headerdep - Detect inclusion cycles in headers'
1458 @echo ' coccicheck - Check with Coccinelle'
1460 @echo 'Kernel selftest:'
1461 @echo ' kselftest - Build and run kernel selftest (run as root)'
1462 @echo ' Build, install, and boot kernel before'
1463 @echo ' running kselftest on it'
1464 @echo ' kselftest-clean - Remove all generated kselftest files'
1465 @echo ' kselftest-merge - Merge all the config dependencies of kselftest to existing'
1469 echo 'Devicetree:'; \
1470 echo '* dtbs - Build device tree blobs for enabled boards'; \
1471 echo ' dtbs_install - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1474 @echo 'Userspace tools targets:'
1475 @echo ' use "make tools/help"'
1476 @echo ' or "cd tools; make help"'
1478 @echo 'Kernel packaging:'
1479 @$(MAKE) $(build)=$(package-dir) help
1481 @echo 'Documentation targets:'
1482 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1484 @echo 'Architecture specific targets ($(SRCARCH)):'
1485 @$(if $(archhelp),$(archhelp),\
1486 echo ' No architecture specific help defined for $(SRCARCH)')
1489 $(foreach b, $(boards), \
1490 printf " %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1492 @$(if $(board-dirs), \
1493 $(foreach b, $(board-dirs), \
1494 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1495 printf " %-16s - Show all of the above\\n" help-boards; \
1498 @echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1499 @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
1500 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1501 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK (sparse by default)'
1502 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1503 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1504 @echo ' make W=n [targets] Enable extra gcc checks, n=1,2,3 where'
1505 @echo ' 1: warnings which may be relevant and do not occur too often'
1506 @echo ' 2: warnings which occur quite often but may still be relevant'
1507 @echo ' 3: more obscure warnings, can most likely be ignored'
1508 @echo ' Multiple levels can be combined with W=12 or W=123'
1510 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1511 @echo 'For further info see the ./README file'
1514 help-board-dirs := $(addprefix help-,$(board-dirs))
1516 help-boards: $(help-board-dirs)
1518 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1520 $(help-board-dirs): help-%:
1521 @echo 'Architecture specific targets ($(SRCARCH) $*):'
1522 @$(if $(boards-per-dir), \
1523 $(foreach b, $(boards-per-dir), \
1524 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1528 # Documentation targets
1529 # ---------------------------------------------------------------------------
1530 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1531 linkcheckdocs dochelp refcheckdocs
1532 PHONY += $(DOC_TARGETS)
1533 $(DOC_TARGETS): scripts_basic FORCE
1534 $(Q)$(MAKE) $(build)=Documentation $@
1536 else # KBUILD_EXTMOD
1539 # External module support.
1540 # When building external modules the kernel used as basis is considered
1541 # read-only, and no consistency checks are made and the make
1542 # system is not used on the basis kernel. If updates are required
1543 # in the basis kernel ordinary make commands (without M=...) must
1546 # The following are the only valid targets when building external
1548 # make M=dir clean Delete all automatically generated files
1549 # make M=dir modules Make all modules in specified dir
1550 # make M=dir Same as 'make M=dir modules'
1551 # make M=dir modules_install
1552 # Install the modules built in the module directory
1553 # Assumes install directory is already created
1555 # We are always building modules
1558 PHONY += $(objtree)/Module.symvers
1559 $(objtree)/Module.symvers:
1560 @test -e $(objtree)/Module.symvers || ( \
1562 echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1563 echo " is missing; modules will have no dependencies and modversions."; \
1566 module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
1567 PHONY += $(module-dirs) modules
1568 $(module-dirs): prepare $(objtree)/Module.symvers
1569 $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
1571 modules: $(module-dirs)
1572 @$(kecho) ' Building modules, stage 2.';
1573 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1575 PHONY += modules_install
1576 modules_install: _emodinst_ _emodinst_post
1578 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1581 $(Q)mkdir -p $(MODLIB)/$(install-dir)
1582 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1584 PHONY += _emodinst_post
1585 _emodinst_post: _emodinst_
1588 clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))
1590 PHONY += $(clean-dirs) clean
1592 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1594 clean: rm-dirs := $(MODVERDIR)
1595 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1599 @echo ' Building external modules.'
1600 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1602 @echo ' modules - default target, build the module(s)'
1603 @echo ' modules_install - install the module'
1604 @echo ' clean - remove generated files in module directory only'
1610 endif # KBUILD_EXTMOD
1612 clean: $(clean-dirs)
1615 @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1616 \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1618 -o -name '*.dtb' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1619 -o -name '*.dwo' -o -name '*.lst' \
1621 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1622 -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1623 -o -name '*.asn1.[ch]' \
1624 -o -name '*.symtypes' -o -name 'modules.order' \
1625 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1626 -o -name '*.c.[012]*.*' \
1628 -o -name '*.gcno' \) -type f -print | xargs rm -f
1630 # Generate tags for editors
1631 # ---------------------------------------------------------------------------
1632 quiet_cmd_tags = GEN $@
1633 cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
1635 tags TAGS cscope gtags: FORCE
1638 # Scripts to check various things for consistency
1639 # ---------------------------------------------------------------------------
1641 PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1644 find $(srctree)/* $(RCS_FIND_IGNORE) \
1645 -name '*.[hcS]' -type f -print | sort \
1646 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1649 find $(srctree)/* $(RCS_FIND_IGNORE) \
1650 -name '*.[hcS]' -type f -print | sort \
1651 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1654 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1657 $(PERL) $(srctree)/scripts/namespace.pl
1660 $(PERL) $(srctree)/scripts/export_report.pl
1662 PHONY += checkstack kernelrelease kernelversion image_name
1664 # UML needs a little special treatment here. It wants to use the host
1665 # toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
1666 # else wants $(ARCH), including people doing cross-builds, which means
1667 # that $(SUBARCH) doesn't work here.
1669 CHECKSTACK_ARCH := $(SUBARCH)
1671 CHECKSTACK_ARCH := $(ARCH)
1674 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1675 $(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1678 @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1681 @echo $(KERNELVERSION)
1684 @echo $(KBUILD_IMAGE)
1686 # Clear a bunch of variables before executing the submake
1688 $(Q)mkdir -p $(objtree)/tools
1689 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/
1692 $(Q)mkdir -p $(objtree)/tools
1693 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/ $*
1696 # ---------------------------------------------------------------------------
1697 # Single targets are compatible with:
1698 # - build with mixed source and output
1699 # - build with separate output dir 'make O=...'
1700 # - external modules
1702 # target-dir => where to store outputfile
1703 # build-dir => directory in kernel source tree to use
1705 ifeq ($(KBUILD_EXTMOD),)
1706 build-dir = $(patsubst %/,%,$(dir $@))
1707 target-dir = $(dir $@)
1709 zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
1710 build-dir = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
1711 target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@))
1714 %.s: %.c prepare FORCE
1715 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1716 %.i: %.c prepare FORCE
1717 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1718 %.o: %.c prepare FORCE
1719 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1720 %.lst: %.c prepare FORCE
1721 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1722 %.s: %.S prepare FORCE
1723 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1724 %.o: %.S prepare FORCE
1725 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1726 %.symtypes: %.c prepare FORCE
1727 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1728 %.ll: %.c prepare FORCE
1729 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1733 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1734 $(build)=$(build-dir)
1735 # Make sure the latest headers are built for Documentation
1736 Documentation/ samples/: headers_install
1738 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1739 $(build)=$(build-dir)
1741 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1742 $(build)=$(build-dir) $(@:.ko=.o)
1743 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1745 # FIXME Should go into a make.lib or something
1746 # ===========================================================================
1748 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs)))
1749 cmd_rmdirs = rm -rf $(rm-dirs)
1751 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
1752 cmd_rmfiles = rm -f $(rm-files)
1754 # Run depmod only if we have System.map and depmod is executable
1755 quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
1756 cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1759 # Create temporary dir for module support files
1760 # clean it up only when building all modules
1761 cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
1762 $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
1764 # read saved command lines for existing targets
1765 existing-targets := $(wildcard $(sort $(targets)))
1767 cmd_files := $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1768 $(cmd_files): ; # Do not try to update included dependency files
1769 -include $(cmd_files)
1771 endif # ifeq ($(config-targets),1)
1772 endif # ifeq ($(mixed-targets),1)
1773 endif # skip-makefile
1778 # Declare the contents of the PHONY variable as phony. We keep that
1779 # information in a variable so we can use it in if_changed and friends.