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 # Ugly workaround for Debian make-kpkg:
35 # make-kpkg directly includes the top Makefile of Linux kernel. In such a case,
36 # skip sub-make to support debian_* targets in ruleset/kernel_version.mk, but
37 # displays warning to discourage such abusage.
38 ifneq ($(word 2, $(MAKEFILE_LIST)),)
39 $(warning Do not include top Makefile of Linux Kernel)
44 ifneq ($(sub-make-done),1)
46 # Do not use make's built-in rules and variables
47 # (this increases performance and avoids hard-to-debug behaviour)
50 # 'MAKEFLAGS += -rR' does not become immediately effective for old
51 # GNU Make versions. Cancel implicit rules for this Makefile.
52 $(lastword $(MAKEFILE_LIST)): ;
54 # Avoid funny character set dependencies
58 export LC_COLLATE LC_NUMERIC
60 # Avoid interference with shell env settings
64 # ---------------------------------------------------------------------------
66 # Normally, we echo the whole command before executing it. By making
67 # that echo $($(quiet)$(cmd)), we now have the possibility to set
68 # $(quiet) to choose other forms of output instead, e.g.
70 # quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
71 # cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
73 # If $(quiet) is empty, the whole command will be printed.
74 # If it is set to "quiet_", only the short version will be printed.
75 # If it is set to "silent_", nothing will be printed at all, since
76 # the variable $(silent_cmd_cc_o_c) doesn't exist.
78 # A simple variant is to prefix commands with $(Q) - that's useful
79 # for commands that shall be hidden in non-verbose mode.
83 # If KBUILD_VERBOSE equals 0 then the above command will be hidden.
84 # If KBUILD_VERBOSE equals 1 then the above command is displayed.
86 # To put more focus on warnings, be less verbose as default
87 # Use 'make V=1' to see the full commands
89 ifeq ("$(origin V)", "command line")
96 ifeq ($(KBUILD_VERBOSE),1)
104 # If the user is running make -s (silent mode), suppress echoing of
107 ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
111 export quiet Q KBUILD_VERBOSE
113 # kbuild supports saving output files in a separate directory.
114 # To locate output files in a separate directory two syntaxes are supported.
115 # In both cases the working directory must be the root of the kernel src.
117 # Use "make O=dir/to/store/output/files/"
119 # 2) Set KBUILD_OUTPUT
120 # Set the environment variable KBUILD_OUTPUT to point to the directory
121 # where the output files shall be placed.
122 # export KBUILD_OUTPUT=dir/to/store/output/files/
125 # The O= assignment takes precedence over the KBUILD_OUTPUT environment
128 # KBUILD_SRC is not intended to be used by the regular user (for now),
129 # it is set on invocation of make with KBUILD_OUTPUT or O= specified.
131 # OK, Make called in directory where kernel src resides
132 # Do we want to locate output files in a separate directory?
133 ifeq ("$(origin O)", "command line")
134 KBUILD_OUTPUT := $(O)
137 ifneq ($(words $(subst :, ,$(CURDIR))), 1)
138 $(error main directory cannot contain spaces nor colons)
141 ifneq ($(KBUILD_OUTPUT),)
142 # check that the output directory actually exists
143 saved-output := $(KBUILD_OUTPUT)
144 KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
146 $(if $(KBUILD_OUTPUT),, \
147 $(error failed to create output directory "$(saved-output)"))
149 # Look for make include files relative to root of kernel src
151 # This does not become effective immediately because MAKEFLAGS is re-parsed
152 # once after the Makefile is read. It is OK since we are going to invoke
154 MAKEFLAGS += --include-dir=$(CURDIR)
158 # Do not print "Entering directory ..." at all for in-tree build.
159 MAKEFLAGS += --no-print-directory
161 endif # ifneq ($(KBUILD_OUTPUT),)
163 PHONY += $(MAKECMDGOALS) sub-make
165 $(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
168 # Invoke a second make in the output directory, passing relevant variables
170 $(Q)$(MAKE) sub-make-done=1 \
171 $(if $(KBUILD_OUTPUT),-C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR)) \
172 -f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS))
175 # We process the rest of the Makefile if this is the final invocation of make
177 # Do not print "Entering directory ...",
178 # but we want to display it when entering to the output directory
179 # so that IDEs/editors are able to understand relative filenames.
180 MAKEFLAGS += --no-print-directory
182 # Call a source code checker (by default, "sparse") as part of the
185 # Use 'make C=1' to enable checking of only re-compiled files.
186 # Use 'make C=2' to enable checking of *all* source files, regardless
187 # of whether they are re-compiled or not.
189 # See the file "Documentation/dev-tools/sparse.rst" for more details,
190 # including where to get the "sparse" utility.
192 ifeq ("$(origin C)", "command line")
193 KBUILD_CHECKSRC = $(C)
195 ifndef KBUILD_CHECKSRC
199 # Use make M=dir to specify directory of external module to build
200 # Old syntax make ... SUBDIRS=$PWD is still supported
201 # Setting the environment variable KBUILD_EXTMOD take precedence
203 $(warning ================= WARNING ================)
204 $(warning 'SUBDIRS' will be removed after Linux 5.3)
205 $(warning Please use 'M=' or 'KBUILD_EXTMOD' instead)
206 $(warning ==========================================)
207 KBUILD_EXTMOD ?= $(SUBDIRS)
210 ifeq ("$(origin M)", "command line")
211 KBUILD_EXTMOD := $(M)
214 ifeq ($(KBUILD_SRC),)
215 # building in the source tree
218 ifeq ($(KBUILD_SRC)/,$(dir $(CURDIR)))
219 # building in a subdirectory of the source tree
222 srctree := $(KBUILD_SRC)
226 export KBUILD_CHECKSRC KBUILD_EXTMOD KBUILD_SRC
234 export srctree objtree VPATH
236 # To make sure we do not include .config for any of the *config targets
237 # catch them early, and hand them over to scripts/kconfig/Makefile
238 # It is allowed to specify more targets when calling make, including
239 # mixing *config targets and build targets.
240 # For example 'make oldconfig all'.
241 # Detect when mixed targets is specified, and make a second invocation
242 # of make so .config is not included in this case either (for *config).
244 version_h := include/generated/uapi/linux/version.h
245 old_version_h := include/linux/version.h
247 clean-targets := %clean mrproper cleandocs
248 no-dot-config-targets := $(clean-targets) \
249 cscope gtags TAGS tags help% %docs check% coccicheck \
250 $(version_h) headers_% archheaders archscripts \
251 %asm-generic kernelversion %src-pkg
252 no-sync-config-targets := $(no-dot-config-targets) install %install \
260 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
261 ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
266 ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
267 ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
272 ifneq ($(KBUILD_EXTMOD),)
276 ifeq ($(KBUILD_EXTMOD),)
277 ifneq ($(filter config %config,$(MAKECMDGOALS)),)
279 ifneq ($(words $(MAKECMDGOALS)),1)
285 # For "make -j clean all", "make -j mrproper defconfig all", etc.
286 ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
287 ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
292 # install and modules_install need also be processed one by one
293 ifneq ($(filter install,$(MAKECMDGOALS)),)
294 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
299 ifeq ($(mixed-targets),1)
300 # ===========================================================================
301 # We're called with mixed targets (*config and build targets).
302 # Handle them one by one.
304 PHONY += $(MAKECMDGOALS) __build_one_by_one
306 $(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
311 for i in $(MAKECMDGOALS); do \
312 $(MAKE) -f $(srctree)/Makefile $$i; \
317 include scripts/Kbuild.include
319 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
320 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
321 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
322 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
324 include scripts/subarch.include
326 # Cross compiling and selecting different set of gcc/bin-utils
327 # ---------------------------------------------------------------------------
329 # When performing cross compilation for other architectures ARCH shall be set
330 # to the target architecture. (See arch/* for the possibilities).
331 # ARCH can be set during invocation of make:
333 # Another way is to have ARCH set in the environment.
334 # The default ARCH is the host where make is executed.
336 # CROSS_COMPILE specify the prefix used for all executables used
337 # during compilation. Only gcc and related bin-utils executables
338 # are prefixed with $(CROSS_COMPILE).
339 # CROSS_COMPILE can be set on the command line
340 # make CROSS_COMPILE=ia64-linux-
341 # Alternatively CROSS_COMPILE can be set in the environment.
342 # Default value for CROSS_COMPILE is not to prefix executables
343 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
346 # Architecture as present in compile.h
347 UTS_MACHINE := $(ARCH)
350 # Additional ARCH settings for x86
354 ifeq ($(ARCH),x86_64)
358 # Additional ARCH settings for sparc
359 ifeq ($(ARCH),sparc32)
362 ifeq ($(ARCH),sparc64)
366 # Additional ARCH settings for sh
371 KCONFIG_CONFIG ?= .config
372 export KCONFIG_CONFIG
374 # SHELL used by kbuild
375 CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
376 else if [ -x /bin/bash ]; then echo /bin/bash; \
377 else echo sh; fi ; fi)
379 HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
380 HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
381 HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
385 KBUILD_HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 \
386 -fomit-frame-pointer -std=gnu89 $(HOST_LFS_CFLAGS) \
388 KBUILD_HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
389 KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
390 KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
392 # Make variables (CC, etc...)
393 AS = $(CROSS_COMPILE)as
394 LD = $(CROSS_COMPILE)ld
395 CC = $(CROSS_COMPILE)gcc
397 AR = $(CROSS_COMPILE)ar
398 NM = $(CROSS_COMPILE)nm
399 STRIP = $(CROSS_COMPILE)strip
400 OBJCOPY = $(CROSS_COMPILE)objcopy
401 OBJDUMP = $(CROSS_COMPILE)objdump
406 INSTALLKERNEL := installkernel
407 DEPMOD = /sbin/depmod
414 CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
415 -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
424 # Use USERINCLUDE when you must reference the UAPI directories only.
426 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
427 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
428 -I$(srctree)/include/uapi \
429 -I$(objtree)/include/generated/uapi \
430 -include $(srctree)/include/linux/kconfig.h
432 # Use LINUXINCLUDE when you must reference the include/ directory.
433 # Needed to be compatible with the O= option
435 -I$(srctree)/arch/$(SRCARCH)/include \
436 -I$(objtree)/arch/$(SRCARCH)/include/generated \
437 $(if $(KBUILD_SRC), -I$(srctree)/include) \
438 -I$(objtree)/include \
441 KBUILD_AFLAGS := -D__ASSEMBLY__ -fno-PIE
442 KBUILD_CFLAGS := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
443 -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
444 -Werror=implicit-function-declaration -Werror=implicit-int \
445 -Wno-format-security \
447 KBUILD_CPPFLAGS := -D__KERNEL__
448 KBUILD_AFLAGS_KERNEL :=
449 KBUILD_CFLAGS_KERNEL :=
450 KBUILD_AFLAGS_MODULE := -DMODULE
451 KBUILD_CFLAGS_MODULE := -DMODULE
452 KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
454 GCC_PLUGINS_CFLAGS :=
456 export ARCH SRCARCH CONFIG_SHELL HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE AS LD CC
457 export CPP AR NM STRIP OBJCOPY OBJDUMP PAHOLE KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS
458 export MAKE LEX YACC AWK INSTALLKERNEL PERL PYTHON PYTHON2 PYTHON3 UTS_MACHINE
459 export HOSTCXX KBUILD_HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
461 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
462 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
463 export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN
464 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
465 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
466 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
467 export KBUILD_ARFLAGS
469 # When compiling out-of-tree modules, put MODVERDIR in the module
470 # tree rather than in the kernel tree. The kernel tree might
472 export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
474 # Files to ignore in find ... statements
476 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
477 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
479 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
480 --exclude CVS --exclude .pc --exclude .hg --exclude .git
482 # ===========================================================================
483 # Rules shared between *config targets and build targets
485 # Basic helpers built in scripts/basic/
486 PHONY += scripts_basic
488 $(Q)$(MAKE) $(build)=scripts/basic
489 $(Q)rm -f .tmp_quiet_recordmcount
491 PHONY += outputmakefile
492 # outputmakefile generates a Makefile in the output directory, if using a
493 # separate output directory. This allows convenient use of make in the
495 # At the same time when output Makefile generated, generate .gitignore to
496 # ignore whole output directory
498 ifneq ($(KBUILD_SRC),)
499 $(Q)ln -fsn $(srctree) source
500 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
501 $(Q){ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
504 ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
505 ifneq ($(CROSS_COMPILE),)
506 CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE:%-=%))
507 GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
508 CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)
509 GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..)
511 ifneq ($(GCC_TOOLCHAIN),)
512 CLANG_FLAGS += --gcc-toolchain=$(GCC_TOOLCHAIN)
514 CLANG_FLAGS += -no-integrated-as
515 KBUILD_CFLAGS += $(CLANG_FLAGS)
516 KBUILD_AFLAGS += $(CLANG_FLAGS)
520 RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
521 RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
522 RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
523 RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
524 RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
525 RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
526 export RETPOLINE_CFLAGS
527 export RETPOLINE_VDSO_CFLAGS
529 # The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
530 # Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
531 # CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
532 # and from include/config/auto.conf.cmd to detect the compiler upgrade.
533 CC_VERSION_TEXT = $(shell $(CC) --version | head -n 1)
535 ifeq ($(config-targets),1)
536 # ===========================================================================
537 # *config targets only - make sure prerequisites are updated, and descend
538 # in scripts/kconfig to make the *config target
540 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
541 # KBUILD_DEFCONFIG may point out an alternative default configuration
542 # used for 'make defconfig'
543 include arch/$(SRCARCH)/Makefile
544 export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
546 config: scripts_basic outputmakefile FORCE
547 $(Q)$(MAKE) $(build)=scripts/kconfig $@
549 %config: scripts_basic outputmakefile FORCE
550 $(Q)$(MAKE) $(build)=scripts/kconfig $@
553 # ===========================================================================
554 # Build targets only - this includes vmlinux, arch specific targets, clean
555 # targets and others. In general all targets except *config targets.
557 # If building an external module we do not care about the all: rule
558 # but instead _all depend on modules
560 ifeq ($(KBUILD_EXTMOD),)
566 # Decide whether to build built-in, modular, or both.
567 # Normally, just do built-in.
572 # If we have only "make modules", don't compile built-in objects.
573 # When we're building modules with modversions, we need to consider
574 # the built-in objects during the descend as well, in order to
575 # make sure the checksums are up to date before we record them.
577 ifeq ($(MAKECMDGOALS),modules)
578 KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
581 # If we have "make <whatever> modules", compile modules
582 # in addition to whatever we do anyway.
583 # Just "make" or "make all" shall build modules as well
585 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
589 ifeq ($(MAKECMDGOALS),)
593 export KBUILD_MODULES KBUILD_BUILTIN
595 ifeq ($(KBUILD_EXTMOD),)
596 # Objects we will link into vmlinux / subdirs we need to visit
598 drivers-y := drivers/ sound/
603 endif # KBUILD_EXTMOD
605 ifeq ($(dot-config),1)
606 include include/config/auto.conf
609 # The all: target is the default when no target is given on the
611 # This allow a user to issue only 'make' to build a kernel including modules
612 # Defaults to vmlinux, but the arch makefile usually adds further targets
615 CFLAGS_GCOV := -fprofile-arcs -ftest-coverage \
616 $(call cc-option,-fno-tree-loop-im) \
617 $(call cc-disable-warning,maybe-uninitialized,)
620 # The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
621 ifdef CONFIG_FUNCTION_TRACER
622 CC_FLAGS_FTRACE := -pg
625 # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
626 # values of the respective KBUILD_* variables
630 include arch/$(SRCARCH)/Makefile
632 ifeq ($(dot-config),1)
633 ifeq ($(may-sync-config),1)
634 # Read in dependencies to all Kconfig* files, make sure to run syncconfig if
635 # changes are detected. This should be included after arch/$(SRCARCH)/Makefile
636 # because some architectures define CROSS_COMPILE there.
637 -include include/config/auto.conf.cmd
641 @echo >&2 '*** Configuration file "$@" not found!'
643 @echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
644 @echo >&2 '*** "make menuconfig" or "make xconfig").'
648 # The actual configuration files used during the build are stored in
649 # include/generated/ and include/config/. Update them if .config is newer than
650 # include/config/auto.conf (which mirrors .config).
652 # This exploits the 'multi-target pattern rule' trick.
653 # The syncconfig should be executed only once to make all the targets.
654 %/auto.conf %/auto.conf.cmd %/tristate.conf: $(KCONFIG_CONFIG)
655 $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
657 # External modules and some install targets need include/generated/autoconf.h
658 # and include/config/auto.conf but do not care if they are up-to-date.
659 # Use auto.conf to trigger the test
660 PHONY += include/config/auto.conf
662 include/config/auto.conf:
663 $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
665 echo >&2 " ERROR: Kernel configuration is invalid."; \
666 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
667 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
671 endif # may-sync-config
672 endif # $(dot-config)
674 KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
675 KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
676 KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
677 KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
678 KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context)
680 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
681 KBUILD_CFLAGS += $(call cc-option,-Oz,-Os)
686 ifdef CONFIG_CC_DISABLE_WARN_MAYBE_UNINITIALIZED
687 KBUILD_CFLAGS += -Wno-maybe-uninitialized
690 # Tell gcc to never replace conditional load with a non-conditional one
691 KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
693 include scripts/Makefile.kcov
694 include scripts/Makefile.gcc-plugins
696 ifdef CONFIG_READABLE_ASM
697 # Disable optimizations that make assembler listings hard to read.
698 # reorder blocks reorders the control in the function
699 # ipa clone creates specialized cloned functions
700 # partial inlining inlines only parts of functions
701 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
702 $(call cc-option,-fno-ipa-cp-clone,) \
703 $(call cc-option,-fno-partial-inlining)
706 ifneq ($(CONFIG_FRAME_WARN),0)
707 KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
710 stackp-flags-$(CONFIG_CC_HAS_STACKPROTECTOR_NONE) := -fno-stack-protector
711 stackp-flags-$(CONFIG_STACKPROTECTOR) := -fstack-protector
712 stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong
714 KBUILD_CFLAGS += $(stackp-flags-y)
716 ifdef CONFIG_CC_IS_CLANG
717 KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
718 KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
719 KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
720 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
721 # Quiet clang warning: comparison of unsigned expression < 0 is always false
722 KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
723 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
724 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
725 # See modpost pattern 2
726 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
727 KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
730 # These warnings generated too much noise in a regular build.
731 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
732 KBUILD_CFLAGS += -Wno-unused-but-set-variable
735 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
736 ifdef CONFIG_FRAME_POINTER
737 KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
739 # Some targets (ARM with Thumb2, for example), can't be built with frame
740 # pointers. For those, we don't have FUNCTION_TRACER automatically
741 # select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
742 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
743 # -fomit-frame-pointer with FUNCTION_TRACER.
744 ifndef CONFIG_FUNCTION_TRACER
745 KBUILD_CFLAGS += -fomit-frame-pointer
749 DEBUG_CFLAGS := $(call cc-option, -fno-var-tracking-assignments)
751 ifdef CONFIG_DEBUG_INFO
752 ifdef CONFIG_DEBUG_INFO_SPLIT
753 DEBUG_CFLAGS += -gsplit-dwarf
757 KBUILD_AFLAGS += -Wa,-gdwarf-2
759 ifdef CONFIG_DEBUG_INFO_DWARF4
760 DEBUG_CFLAGS += -gdwarf-4
763 ifdef CONFIG_DEBUG_INFO_REDUCED
764 DEBUG_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
765 $(call cc-option,-fno-var-tracking)
768 KBUILD_CFLAGS += $(DEBUG_CFLAGS)
771 ifdef CONFIG_FUNCTION_TRACER
772 ifdef CONFIG_FTRACE_MCOUNT_RECORD
773 # gcc 5 supports generating the mcount tables directly
774 ifeq ($(call cc-option-yn,-mrecord-mcount),y)
775 CC_FLAGS_FTRACE += -mrecord-mcount
776 export CC_USING_RECORD_MCOUNT := 1
778 ifdef CONFIG_HAVE_NOP_MCOUNT
779 ifeq ($(call cc-option-yn, -mnop-mcount),y)
780 CC_FLAGS_FTRACE += -mnop-mcount
781 CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
785 ifdef CONFIG_HAVE_FENTRY
786 ifeq ($(call cc-option-yn, -mfentry),y)
787 CC_FLAGS_FTRACE += -mfentry
788 CC_FLAGS_USING += -DCC_USING_FENTRY
791 export CC_FLAGS_FTRACE
792 KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
793 KBUILD_AFLAGS += $(CC_FLAGS_USING)
794 ifdef CONFIG_DYNAMIC_FTRACE
795 ifdef CONFIG_HAVE_C_RECORDMCOUNT
796 BUILD_C_RECORDMCOUNT := y
797 export BUILD_C_RECORDMCOUNT
802 # We trigger additional mismatches with less inlining
803 ifdef CONFIG_DEBUG_SECTION_MISMATCH
804 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
807 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
808 KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
809 LDFLAGS_vmlinux += --gc-sections
812 # arch Makefile may override CC so keep this after arch Makefile is included
813 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
815 # warn about C99 declaration after statement
816 KBUILD_CFLAGS += -Wdeclaration-after-statement
818 # Variable Length Arrays (VLAs) should not be used anywhere in the kernel
819 KBUILD_CFLAGS += $(call cc-option,-Wvla)
821 # disable pointer signed / unsigned warnings in gcc 4.0
822 KBUILD_CFLAGS += -Wno-pointer-sign
824 # disable stringop warnings in gcc 8+
825 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
827 # disable invalid "can't wrap" optimizations for signed / pointers
828 KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
830 # clang sets -fmerge-all-constants by default as optimization, but this
831 # is non-conforming behavior for C and in fact breaks the kernel, so we
832 # need to disable it here generally.
833 KBUILD_CFLAGS += $(call cc-option,-fno-merge-all-constants)
835 # for gcc -fno-merge-all-constants disables everything, but it is fine
836 # to have actual conforming behavior enabled.
837 KBUILD_CFLAGS += $(call cc-option,-fmerge-constants)
839 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
840 KBUILD_CFLAGS += $(call cc-option,-fno-stack-check,)
842 # conserve stack if available
843 KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
845 # Prohibit date/time macros, which would make the build non-deterministic
846 KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
848 # enforce correct pointer usage
849 KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
851 # Require designated initializers for all marked structures
852 KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
854 # change __FILE__ to the relative path from the srctree
855 KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
857 # use the deterministic mode of AR if available
858 KBUILD_ARFLAGS := $(call ar-option,D)
860 include scripts/Makefile.kasan
861 include scripts/Makefile.extrawarn
862 include scripts/Makefile.ubsan
864 # Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
866 KBUILD_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS)
867 KBUILD_AFLAGS += $(ARCH_AFLAGS) $(KAFLAGS)
868 KBUILD_CFLAGS += $(ARCH_CFLAGS) $(KCFLAGS)
870 # Use --build-id when available.
871 LDFLAGS_BUILD_ID := $(call ld-option, --build-id)
872 KBUILD_LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
873 LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
875 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
876 LDFLAGS_vmlinux += $(call ld-option, -X,)
879 # insure the checker run with the right endianness
880 CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
882 # the checker needs the correct machine size
883 CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
885 # Default kernel image to build when no specific target is given.
886 # KBUILD_IMAGE may be overruled on the command line or
887 # set in the environment
888 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
890 export KBUILD_IMAGE ?= vmlinux
893 # INSTALL_PATH specifies where to place the updated kernel and system map
894 # images. Default is /boot, but you can set it to other values
895 export INSTALL_PATH ?= /boot
898 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
899 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
900 # an argument if needed. Otherwise it defaults to the kernel install path
902 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
905 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
906 # relocations required by build roots. This is not defined in the
907 # makefile but the argument can be passed to make if needed.
910 MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
914 # INSTALL_MOD_STRIP, if defined, will cause modules to be
915 # stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
916 # the default option --strip-debug will be used. Otherwise,
917 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
919 ifdef INSTALL_MOD_STRIP
920 ifeq ($(INSTALL_MOD_STRIP),1)
921 mod_strip_cmd = $(STRIP) --strip-debug
923 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
924 endif # INSTALL_MOD_STRIP=1
927 endif # INSTALL_MOD_STRIP
930 # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
931 # after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
932 # or CONFIG_MODULE_COMPRESS_XZ.
934 mod_compress_cmd = true
935 ifdef CONFIG_MODULE_COMPRESS
936 ifdef CONFIG_MODULE_COMPRESS_GZIP
937 mod_compress_cmd = gzip -n -f
938 endif # CONFIG_MODULE_COMPRESS_GZIP
939 ifdef CONFIG_MODULE_COMPRESS_XZ
940 mod_compress_cmd = xz -f
941 endif # CONFIG_MODULE_COMPRESS_XZ
942 endif # CONFIG_MODULE_COMPRESS
943 export mod_compress_cmd
945 ifdef CONFIG_MODULE_SIG_ALL
946 $(eval $(call config_filename,MODULE_SIG_KEY))
948 mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
954 ifdef CONFIG_STACK_VALIDATION
955 has_libelf := $(call try-run,\
956 echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0)
957 ifeq ($(has_libelf),1)
958 objtool_target := tools/objtool FORCE
960 SKIP_STACK_VALIDATION := 1
961 export SKIP_STACK_VALIDATION
967 ifeq ($(KBUILD_EXTMOD),)
968 core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
970 vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
971 $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
972 $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
974 vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
975 $(init-) $(core-) $(drivers-) $(net-) $(libs-) $(virt-))))
977 init-y := $(patsubst %/, %/built-in.a, $(init-y))
978 core-y := $(patsubst %/, %/built-in.a, $(core-y))
979 drivers-y := $(patsubst %/, %/built-in.a, $(drivers-y))
980 net-y := $(patsubst %/, %/built-in.a, $(net-y))
981 libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
982 libs-y2 := $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y)))
983 virt-y := $(patsubst %/, %/built-in.a, $(virt-y))
985 # Externally visible symbols (used by link-vmlinux.sh)
986 export KBUILD_VMLINUX_OBJS := $(head-y) $(init-y) $(core-y) $(libs-y2) \
987 $(drivers-y) $(net-y) $(virt-y)
988 export KBUILD_VMLINUX_LIBS := $(libs-y1)
989 export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
990 export LDFLAGS_vmlinux
991 # used by scripts/package/Makefile
992 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools)
994 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
996 # Recurse until adjust_autoksyms.sh is satisfied
997 PHONY += autoksyms_recursive
998 autoksyms_recursive: $(vmlinux-deps)
999 ifdef CONFIG_TRIM_UNUSED_KSYMS
1000 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1001 "$(MAKE) -f $(srctree)/Makefile vmlinux"
1004 # For the kernel to actually contain only the needed exported symbols,
1005 # we have to build modules as well to determine what those symbols are.
1006 # (this can be evaluated only once include/config/auto.conf has been included)
1007 ifdef CONFIG_TRIM_UNUSED_KSYMS
1011 autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1014 $(Q)mkdir -p $(dir $@)
1017 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1019 # Final link of vmlinux with optional arch pass after final link
1020 cmd_link-vmlinux = \
1021 $(CONFIG_SHELL) $< $(LD) $(KBUILD_LDFLAGS) $(LDFLAGS_vmlinux) ; \
1022 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1024 vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1025 +$(call if_changed,link-vmlinux)
1029 # Build samples along the rest of the kernel. This needs headers_install.
1030 ifdef CONFIG_SAMPLES
1031 vmlinux-dirs += samples
1032 samples: headers_install
1035 # The actual objects are generated when descending,
1036 # make sure no implicit rule kicks in
1037 $(sort $(vmlinux-deps)): $(vmlinux-dirs) ;
1039 # Handle descending into subdirectories listed in $(vmlinux-dirs)
1040 # Preset locale variables to speed up the build process. Limit locale
1041 # tweaks to this spot to avoid wrong language settings when running
1042 # make menuconfig etc.
1043 # Error messages still appears in the original language
1045 PHONY += $(vmlinux-dirs)
1046 $(vmlinux-dirs): prepare
1047 $(Q)$(MAKE) $(build)=$@ need-builtin=1
1049 filechk_kernel.release = \
1050 echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1052 # Store (new) KERNELRELEASE string in include/config/kernel.release
1053 include/config/kernel.release: $(srctree)/Makefile FORCE
1054 $(call filechk,kernel.release)
1056 # Additional helpers built in scripts/
1057 # Carefully list dependencies so we do not try to build scripts twice
1060 scripts: scripts_basic scripts_dtc
1061 $(Q)$(MAKE) $(build)=$(@)
1063 # Things we need to do before we recursively start building the kernel
1064 # or the modules are listed in "prepare".
1065 # A multi level approach is used. prepareN is processed before prepareN-1.
1066 # archprepare is used in arch Makefiles and when processed asm symlink,
1067 # version.h and scripts_basic is processed / created.
1069 PHONY += prepare archprepare prepare1 prepare3
1071 # prepare3 is used to check if we are building in a separate output directory,
1073 # 1) Check that make has not been executed in the kernel src $(srctree)
1074 prepare3: include/config/kernel.release
1075 ifneq ($(KBUILD_SRC),)
1076 @$(kecho) ' Using $(srctree) as source for kernel'
1077 $(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
1078 echo >&2 " $(srctree) is not clean, please run 'make mrproper'"; \
1079 echo >&2 " in the '$(srctree)' directory.";\
1084 prepare1: prepare3 outputmakefile asm-generic $(version_h) $(autoksyms_h) \
1085 include/generated/utsrelease.h
1088 archprepare: archheaders archscripts prepare1 scripts
1090 prepare0: archprepare
1091 $(Q)$(MAKE) $(build)=scripts/mod
1092 $(Q)$(MAKE) $(build)=.
1094 # All the preparing..
1095 prepare: prepare0 prepare-objtool
1097 # Support for using generic headers in asm-generic
1098 asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1100 PHONY += asm-generic uapi-asm-generic
1101 asm-generic: uapi-asm-generic
1102 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1103 generic=include/asm-generic
1105 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1106 generic=include/uapi/asm-generic
1108 PHONY += prepare-objtool
1109 prepare-objtool: $(objtool_target)
1110 ifeq ($(SKIP_STACK_VALIDATION),1)
1111 ifdef CONFIG_UNWINDER_ORC
1112 @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1115 @echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1119 # Generate some files
1120 # ---------------------------------------------------------------------------
1122 # KERNELRELEASE can change from a few different places, meaning version.h
1123 # needs to be updated, so this check is forced on all builds
1126 define filechk_utsrelease.h
1127 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1128 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1131 echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1134 define filechk_version.h
1135 echo \#define LINUX_VERSION_CODE $(shell \
1136 expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
1137 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))'
1141 $(call filechk,version.h)
1142 $(Q)rm -f $(old_version_h)
1144 include/generated/utsrelease.h: include/config/kernel.release FORCE
1145 $(call filechk,utsrelease.h)
1149 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1150 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1152 # ---------------------------------------------------------------------------
1155 #Default location for installed headers
1156 export INSTALL_HDR_PATH = $(objtree)/usr
1158 # If we do an all arch process set dst to include/arch-$(SRCARCH)
1159 hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(SRCARCH), dst=include)
1161 PHONY += archheaders archscripts
1164 __headers: $(version_h) scripts_basic uapi-asm-generic archheaders archscripts
1165 $(Q)$(MAKE) $(build)=scripts build_unifdef
1167 PHONY += headers_install_all
1168 headers_install_all:
1169 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh install
1171 PHONY += headers_install
1172 headers_install: __headers
1173 $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1174 $(error Headers not exportable for the $(SRCARCH) architecture))
1175 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include
1176 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst)
1178 PHONY += headers_check_all
1179 headers_check_all: headers_install_all
1180 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh check
1182 PHONY += headers_check
1183 headers_check: headers_install
1184 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include HDRCHECK=1
1185 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst) HDRCHECK=1
1187 ifdef CONFIG_HEADERS_CHECK
1191 # ---------------------------------------------------------------------------
1196 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1198 PHONY += kselftest-clean
1200 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests clean
1202 PHONY += kselftest-merge
1204 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1205 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \
1206 -m $(objtree)/.config \
1207 $(srctree)/tools/testing/selftests/*/config
1208 +$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1210 # ---------------------------------------------------------------------------
1213 ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1214 dtstree := arch/$(SRCARCH)/boot/dts
1219 %.dtb: prepare3 scripts_dtc
1220 $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1222 PHONY += dtbs dtbs_install dt_binding_check
1223 dtbs dtbs_check: prepare3 scripts_dtc
1224 $(Q)$(MAKE) $(build)=$(dtstree)
1226 dtbs_check: export CHECK_DTBS=1
1227 dtbs_check: dt_binding_check
1230 $(Q)$(MAKE) $(dtbinst)=$(dtstree)
1232 ifdef CONFIG_OF_EARLY_FLATTREE
1238 PHONY += scripts_dtc
1239 scripts_dtc: scripts_basic
1240 $(Q)$(MAKE) $(build)=scripts/dtc
1242 dt_binding_check: scripts_dtc
1243 $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1245 # ---------------------------------------------------------------------------
1248 ifdef CONFIG_MODULES
1250 # By default, build modules as well
1256 # A module can be listed more than once in obj-m resulting in
1257 # duplicate lines in modules.order files. Those are removed
1258 # using awk while concatenating to the final file.
1261 modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
1262 $(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
1263 @$(kecho) ' Building modules, stage 2.';
1264 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1266 modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
1267 $(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
1269 %/modules.builtin: include/config/auto.conf include/config/tristate.conf
1270 $(Q)$(MAKE) $(modbuiltin)=$*
1273 # Target to prepare building external modules
1274 PHONY += modules_prepare
1275 modules_prepare: prepare
1277 # Target to install modules
1278 PHONY += modules_install
1279 modules_install: _modinst_ _modinst_post
1283 @rm -rf $(MODLIB)/kernel
1284 @rm -f $(MODLIB)/source
1285 @mkdir -p $(MODLIB)/kernel
1286 @ln -s $(abspath $(srctree)) $(MODLIB)/source
1287 @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
1288 rm -f $(MODLIB)/build ; \
1289 ln -s $(CURDIR) $(MODLIB)/build ; \
1291 @cp -f $(objtree)/modules.order $(MODLIB)/
1292 @cp -f $(objtree)/modules.builtin $(MODLIB)/
1293 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1295 # This depmod is only for convenience to give the initial
1296 # boot a modules.dep even before / is mounted read-write. However the
1297 # boot script depmod is the master version.
1298 PHONY += _modinst_post
1299 _modinst_post: _modinst_
1302 ifeq ($(CONFIG_MODULE_SIG), y)
1303 PHONY += modules_sign
1305 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1308 else # CONFIG_MODULES
1310 # Modules not configured
1311 # ---------------------------------------------------------------------------
1313 PHONY += modules modules_install
1314 modules modules_install:
1316 @echo >&2 "The present kernel configuration has modules disabled."
1317 @echo >&2 "Type 'make config' and enable loadable module support."
1318 @echo >&2 "Then build a kernel with module support enabled."
1322 endif # CONFIG_MODULES
1325 # Cleaning is done on three levels.
1326 # make clean Delete most generated files
1327 # Leave enough to build external modules
1328 # make mrproper Delete the current configuration, and all generated files
1329 # make distclean Remove editor backup files, patch leftover files and the like
1331 # Directories & files removed with 'make clean'
1332 CLEAN_DIRS += $(MODVERDIR) include/ksym
1334 # Directories & files removed with 'make mrproper'
1335 MRPROPER_DIRS += include/config usr/include include/generated \
1336 arch/*/include/generated .tmp_objdiff
1337 MRPROPER_FILES += .config .config.old .version \
1338 Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
1339 signing_key.pem signing_key.priv signing_key.x509 \
1340 x509.genkey extra_certificates signing_key.x509.keyid \
1341 signing_key.x509.signer vmlinux-gdb.py
1343 # clean - Delete most, but leave enough to build external modules
1345 clean: rm-dirs := $(CLEAN_DIRS)
1346 clean: rm-files := $(CLEAN_FILES)
1347 clean-dirs := $(addprefix _clean_, . $(vmlinux-alldirs) Documentation samples)
1349 PHONY += $(clean-dirs) clean archclean vmlinuxclean
1351 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1354 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1355 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1357 clean: archclean vmlinuxclean
1359 # mrproper - Delete all generated files, including .config
1361 mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS))
1362 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1363 mrproper-dirs := $(addprefix _mrproper_,scripts)
1365 PHONY += $(mrproper-dirs) mrproper
1367 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1369 mrproper: clean $(mrproper-dirs)
1378 @find $(srctree) $(RCS_FIND_IGNORE) \
1379 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1380 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1381 -o -name 'core' \) \
1382 -type f -print | xargs rm -f
1385 # Packaging of the kernel to various formats
1386 # ---------------------------------------------------------------------------
1387 package-dir := scripts/package
1390 $(Q)$(MAKE) $(build)=$(package-dir) $@
1391 %pkg: include/config/kernel.release FORCE
1392 $(Q)$(MAKE) $(build)=$(package-dir) $@
1395 # Brief documentation of the typical targets used
1396 # ---------------------------------------------------------------------------
1398 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1399 boards := $(sort $(notdir $(boards)))
1400 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1401 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1405 @echo 'Cleaning targets:'
1406 @echo ' clean - Remove most generated files but keep the config and'
1407 @echo ' enough build support to build external modules'
1408 @echo ' mrproper - Remove all generated files + config + various backup files'
1409 @echo ' distclean - mrproper + remove editor backup and patch files'
1411 @echo 'Configuration targets:'
1412 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1414 @echo 'Other generic targets:'
1415 @echo ' all - Build all targets marked with [*]'
1416 @echo '* vmlinux - Build the bare kernel'
1417 @echo '* modules - Build all modules'
1418 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1419 @echo ' dir/ - Build all files in dir and below'
1420 @echo ' dir/file.[ois] - Build specified target only'
1421 @echo ' dir/file.ll - Build the LLVM assembly file'
1422 @echo ' (requires compiler support for LLVM assembly generation)'
1423 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1424 @echo ' (requires a recent binutils and recent build (System.map))'
1425 @echo ' dir/file.ko - Build module including final link'
1426 @echo ' modules_prepare - Set up for building external modules'
1427 @echo ' tags/TAGS - Generate tags file for editors'
1428 @echo ' cscope - Generate cscope index'
1429 @echo ' gtags - Generate GNU GLOBAL index'
1430 @echo ' kernelrelease - Output the release version string (use with make -s)'
1431 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1432 @echo ' image_name - Output the image name (use with make -s)'
1433 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1434 echo ' (default: $(INSTALL_HDR_PATH))'; \
1436 @echo 'Static analysers:'
1437 @echo ' checkstack - Generate a list of stack hogs'
1438 @echo ' namespacecheck - Name space analysis on compiled kernel'
1439 @echo ' versioncheck - Sanity check on version.h usage'
1440 @echo ' includecheck - Check for duplicate included header files'
1441 @echo ' export_report - List the usages of all exported symbols'
1442 @echo ' headers_check - Sanity check on exported headers'
1443 @echo ' headerdep - Detect inclusion cycles in headers'
1444 @echo ' coccicheck - Check with Coccinelle'
1446 @echo 'Kernel selftest:'
1447 @echo ' kselftest - Build and run kernel selftest (run as root)'
1448 @echo ' Build, install, and boot kernel before'
1449 @echo ' running kselftest on it'
1450 @echo ' kselftest-clean - Remove all generated kselftest files'
1451 @echo ' kselftest-merge - Merge all the config dependencies of kselftest to existing'
1455 echo 'Devicetree:'; \
1456 echo '* dtbs - Build device tree blobs for enabled boards'; \
1457 echo ' dtbs_install - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1460 @echo 'Userspace tools targets:'
1461 @echo ' use "make tools/help"'
1462 @echo ' or "cd tools; make help"'
1464 @echo 'Kernel packaging:'
1465 @$(MAKE) $(build)=$(package-dir) help
1467 @echo 'Documentation targets:'
1468 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1470 @echo 'Architecture specific targets ($(SRCARCH)):'
1471 @$(if $(archhelp),$(archhelp),\
1472 echo ' No architecture specific help defined for $(SRCARCH)')
1475 $(foreach b, $(boards), \
1476 printf " %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1478 @$(if $(board-dirs), \
1479 $(foreach b, $(board-dirs), \
1480 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1481 printf " %-16s - Show all of the above\\n" help-boards; \
1484 @echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1485 @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
1486 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1487 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK (sparse by default)'
1488 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1489 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1490 @echo ' make W=n [targets] Enable extra gcc checks, n=1,2,3 where'
1491 @echo ' 1: warnings which may be relevant and do not occur too often'
1492 @echo ' 2: warnings which occur quite often but may still be relevant'
1493 @echo ' 3: more obscure warnings, can most likely be ignored'
1494 @echo ' Multiple levels can be combined with W=12 or W=123'
1496 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1497 @echo 'For further info see the ./README file'
1500 help-board-dirs := $(addprefix help-,$(board-dirs))
1502 help-boards: $(help-board-dirs)
1504 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1506 $(help-board-dirs): help-%:
1507 @echo 'Architecture specific targets ($(SRCARCH) $*):'
1508 @$(if $(boards-per-dir), \
1509 $(foreach b, $(boards-per-dir), \
1510 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1514 # Documentation targets
1515 # ---------------------------------------------------------------------------
1516 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1517 linkcheckdocs dochelp refcheckdocs
1518 PHONY += $(DOC_TARGETS)
1519 $(DOC_TARGETS): scripts_basic FORCE
1520 $(Q)$(MAKE) $(build)=Documentation $@
1523 # ---------------------------------------------------------------------------
1525 PHONY += scripts_gdb
1526 scripts_gdb: prepare
1527 $(Q)$(MAKE) $(build)=scripts/gdb
1528 $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1530 ifdef CONFIG_GDB_SCRIPTS
1534 else # KBUILD_EXTMOD
1537 # External module support.
1538 # When building external modules the kernel used as basis is considered
1539 # read-only, and no consistency checks are made and the make
1540 # system is not used on the basis kernel. If updates are required
1541 # in the basis kernel ordinary make commands (without M=...) must
1544 # The following are the only valid targets when building external
1546 # make M=dir clean Delete all automatically generated files
1547 # make M=dir modules Make all modules in specified dir
1548 # make M=dir Same as 'make M=dir modules'
1549 # make M=dir modules_install
1550 # Install the modules built in the module directory
1551 # Assumes install directory is already created
1553 # We are always building modules
1556 PHONY += $(objtree)/Module.symvers
1557 $(objtree)/Module.symvers:
1558 @test -e $(objtree)/Module.symvers || ( \
1560 echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1561 echo " is missing; modules will have no dependencies and modversions."; \
1564 module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
1565 PHONY += $(module-dirs) modules
1566 $(module-dirs): prepare $(objtree)/Module.symvers
1567 $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
1569 modules: $(module-dirs)
1570 @$(kecho) ' Building modules, stage 2.';
1571 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1573 PHONY += modules_install
1574 modules_install: _emodinst_ _emodinst_post
1576 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1579 $(Q)mkdir -p $(MODLIB)/$(install-dir)
1580 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1582 PHONY += _emodinst_post
1583 _emodinst_post: _emodinst_
1586 clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))
1588 PHONY += $(clean-dirs) clean
1590 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1592 clean: rm-dirs := $(MODVERDIR)
1593 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1597 @echo ' Building external modules.'
1598 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1600 @echo ' modules - default target, build the module(s)'
1601 @echo ' modules_install - install the module'
1602 @echo ' clean - remove generated files in module directory only'
1608 endif # KBUILD_EXTMOD
1610 clean: $(clean-dirs)
1613 @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1614 \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1616 -o -name '*.dtb' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1617 -o -name '*.dwo' -o -name '*.lst' \
1619 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1620 -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1621 -o -name '*.asn1.[ch]' \
1622 -o -name '*.symtypes' -o -name 'modules.order' \
1623 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1624 -o -name '*.c.[012]*.*' \
1626 -o -name '*.gcno' \) -type f -print | xargs rm -f
1628 # Generate tags for editors
1629 # ---------------------------------------------------------------------------
1630 quiet_cmd_tags = GEN $@
1631 cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
1633 tags TAGS cscope gtags: FORCE
1636 # Scripts to check various things for consistency
1637 # ---------------------------------------------------------------------------
1639 PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1642 find $(srctree)/* $(RCS_FIND_IGNORE) \
1643 -name '*.[hcS]' -type f -print | sort \
1644 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1647 find $(srctree)/* $(RCS_FIND_IGNORE) \
1648 -name '*.[hcS]' -type f -print | sort \
1649 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1652 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1655 $(PERL) $(srctree)/scripts/namespace.pl
1658 $(PERL) $(srctree)/scripts/export_report.pl
1660 PHONY += checkstack kernelrelease kernelversion image_name
1662 # UML needs a little special treatment here. It wants to use the host
1663 # toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
1664 # else wants $(ARCH), including people doing cross-builds, which means
1665 # that $(SUBARCH) doesn't work here.
1667 CHECKSTACK_ARCH := $(SUBARCH)
1669 CHECKSTACK_ARCH := $(ARCH)
1672 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1673 $(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1676 @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1679 @echo $(KERNELVERSION)
1682 @echo $(KBUILD_IMAGE)
1684 # Clear a bunch of variables before executing the submake
1686 ifeq ($(quiet),silent_)
1691 $(Q)mkdir -p $(objtree)/tools
1692 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/
1695 $(Q)mkdir -p $(objtree)/tools
1696 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/ $*
1699 # ---------------------------------------------------------------------------
1700 # Single targets are compatible with:
1701 # - build with mixed source and output
1702 # - build with separate output dir 'make O=...'
1703 # - external modules
1705 # target-dir => where to store outputfile
1706 # build-dir => directory in kernel source tree to use
1708 build-target = $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD)/)$@
1709 build-dir = $(patsubst %/,%,$(dir $(build-target)))
1712 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1714 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1715 %.lst: prepare FORCE
1716 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1718 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1720 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1721 %.symtypes: prepare FORCE
1722 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1724 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1730 # Make sure the latest headers are built for Documentation
1731 Documentation/ samples/: headers_install
1733 $(Q)$(MAKE) KBUILD_MODULES=1 $(build)=$(build-dir)
1735 # FIXME Should go into a make.lib or something
1736 # ===========================================================================
1738 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs)))
1739 cmd_rmdirs = rm -rf $(rm-dirs)
1741 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
1742 cmd_rmfiles = rm -f $(rm-files)
1744 # Run depmod only if we have System.map and depmod is executable
1745 quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
1746 cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1749 # Create temporary dir for module support files
1750 # clean it up only when building all modules
1751 cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
1752 $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
1754 # read saved command lines for existing targets
1755 existing-targets := $(wildcard $(sort $(targets)))
1757 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1759 endif # ifeq ($(config-targets),1)
1760 endif # ifeq ($(mixed-targets),1)
1761 endif # sub-make-done
1766 # Declare the contents of the PHONY variable as phony. We keep that
1767 # information in a variable so we can use it in if_changed and friends.