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
405 INSTALLKERNEL := installkernel
406 DEPMOD = /sbin/depmod
413 CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
414 -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
423 # Use USERINCLUDE when you must reference the UAPI directories only.
425 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
426 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
427 -I$(srctree)/include/uapi \
428 -I$(objtree)/include/generated/uapi \
429 -include $(srctree)/include/linux/kconfig.h
431 # Use LINUXINCLUDE when you must reference the include/ directory.
432 # Needed to be compatible with the O= option
434 -I$(srctree)/arch/$(SRCARCH)/include \
435 -I$(objtree)/arch/$(SRCARCH)/include/generated \
436 $(if $(KBUILD_SRC), -I$(srctree)/include) \
437 -I$(objtree)/include \
440 KBUILD_AFLAGS := -D__ASSEMBLY__ -fno-PIE
441 KBUILD_CFLAGS := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
442 -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
443 -Werror=implicit-function-declaration -Werror=implicit-int \
444 -Wno-format-security \
446 KBUILD_CPPFLAGS := -D__KERNEL__
447 KBUILD_AFLAGS_KERNEL :=
448 KBUILD_CFLAGS_KERNEL :=
449 KBUILD_AFLAGS_MODULE := -DMODULE
450 KBUILD_CFLAGS_MODULE := -DMODULE
451 KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
453 GCC_PLUGINS_CFLAGS :=
455 export ARCH SRCARCH CONFIG_SHELL HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE AS LD CC
456 export CPP AR NM STRIP OBJCOPY OBJDUMP KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS
457 export MAKE LEX YACC AWK INSTALLKERNEL PERL PYTHON PYTHON2 PYTHON3 UTS_MACHINE
458 export HOSTCXX KBUILD_HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
460 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
461 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
462 export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN
463 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
464 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
465 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
466 export KBUILD_ARFLAGS
468 # When compiling out-of-tree modules, put MODVERDIR in the module
469 # tree rather than in the kernel tree. The kernel tree might
471 export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
473 # Files to ignore in find ... statements
475 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
476 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
478 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
479 --exclude CVS --exclude .pc --exclude .hg --exclude .git
481 # ===========================================================================
482 # Rules shared between *config targets and build targets
484 # Basic helpers built in scripts/basic/
485 PHONY += scripts_basic
487 $(Q)$(MAKE) $(build)=scripts/basic
488 $(Q)rm -f .tmp_quiet_recordmcount
490 PHONY += outputmakefile
491 # outputmakefile generates a Makefile in the output directory, if using a
492 # separate output directory. This allows convenient use of make in the
494 # At the same time when output Makefile generated, generate .gitignore to
495 # ignore whole output directory
497 ifneq ($(KBUILD_SRC),)
498 $(Q)ln -fsn $(srctree) source
499 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
500 $(Q){ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
503 ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
504 ifneq ($(CROSS_COMPILE),)
505 CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE:%-=%))
506 GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
507 CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)
508 GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..)
510 ifneq ($(GCC_TOOLCHAIN),)
511 CLANG_FLAGS += --gcc-toolchain=$(GCC_TOOLCHAIN)
513 CLANG_FLAGS += -no-integrated-as
514 KBUILD_CFLAGS += $(CLANG_FLAGS)
515 KBUILD_AFLAGS += $(CLANG_FLAGS)
519 RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
520 RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
521 RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
522 RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
523 RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
524 RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
525 export RETPOLINE_CFLAGS
526 export RETPOLINE_VDSO_CFLAGS
528 # The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
529 # Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
530 # CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
531 # and from include/config/auto.conf.cmd to detect the compiler upgrade.
532 CC_VERSION_TEXT = $(shell $(CC) --version | head -n 1)
534 ifeq ($(config-targets),1)
535 # ===========================================================================
536 # *config targets only - make sure prerequisites are updated, and descend
537 # in scripts/kconfig to make the *config target
539 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
540 # KBUILD_DEFCONFIG may point out an alternative default configuration
541 # used for 'make defconfig'
542 include arch/$(SRCARCH)/Makefile
543 export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
545 config: scripts_basic outputmakefile FORCE
546 $(Q)$(MAKE) $(build)=scripts/kconfig $@
548 %config: scripts_basic outputmakefile FORCE
549 $(Q)$(MAKE) $(build)=scripts/kconfig $@
552 # ===========================================================================
553 # Build targets only - this includes vmlinux, arch specific targets, clean
554 # targets and others. In general all targets except *config targets.
556 # If building an external module we do not care about the all: rule
557 # but instead _all depend on modules
559 ifeq ($(KBUILD_EXTMOD),)
565 # Decide whether to build built-in, modular, or both.
566 # Normally, just do built-in.
571 # If we have only "make modules", don't compile built-in objects.
572 # When we're building modules with modversions, we need to consider
573 # the built-in objects during the descend as well, in order to
574 # make sure the checksums are up to date before we record them.
576 ifeq ($(MAKECMDGOALS),modules)
577 KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
580 # If we have "make <whatever> modules", compile modules
581 # in addition to whatever we do anyway.
582 # Just "make" or "make all" shall build modules as well
584 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
588 ifeq ($(MAKECMDGOALS),)
592 export KBUILD_MODULES KBUILD_BUILTIN
594 ifeq ($(KBUILD_EXTMOD),)
595 # Objects we will link into vmlinux / subdirs we need to visit
597 drivers-y := drivers/ sound/
602 endif # KBUILD_EXTMOD
604 ifeq ($(dot-config),1)
605 include include/config/auto.conf
608 # The all: target is the default when no target is given on the
610 # This allow a user to issue only 'make' to build a kernel including modules
611 # Defaults to vmlinux, but the arch makefile usually adds further targets
614 CFLAGS_GCOV := -fprofile-arcs -ftest-coverage \
615 $(call cc-option,-fno-tree-loop-im) \
616 $(call cc-disable-warning,maybe-uninitialized,)
619 # The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
620 ifdef CONFIG_FUNCTION_TRACER
621 CC_FLAGS_FTRACE := -pg
624 # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
625 # values of the respective KBUILD_* variables
629 include arch/$(SRCARCH)/Makefile
631 ifeq ($(dot-config),1)
632 ifeq ($(may-sync-config),1)
633 # Read in dependencies to all Kconfig* files, make sure to run syncconfig if
634 # changes are detected. This should be included after arch/$(SRCARCH)/Makefile
635 # because some architectures define CROSS_COMPILE there.
636 -include include/config/auto.conf.cmd
640 @echo >&2 '*** Configuration file "$@" not found!'
642 @echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
643 @echo >&2 '*** "make menuconfig" or "make xconfig").'
647 # The actual configuration files used during the build are stored in
648 # include/generated/ and include/config/. Update them if .config is newer than
649 # include/config/auto.conf (which mirrors .config).
651 # This exploits the 'multi-target pattern rule' trick.
652 # The syncconfig should be executed only once to make all the targets.
653 %/auto.conf %/auto.conf.cmd %/tristate.conf: $(KCONFIG_CONFIG)
654 $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
656 # External modules and some install targets need include/generated/autoconf.h
657 # and include/config/auto.conf but do not care if they are up-to-date.
658 # Use auto.conf to trigger the test
659 PHONY += include/config/auto.conf
661 include/config/auto.conf:
662 $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
664 echo >&2 " ERROR: Kernel configuration is invalid."; \
665 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
666 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
670 endif # may-sync-config
671 endif # $(dot-config)
673 KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
674 KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
675 KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
676 KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
677 KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context)
679 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
680 KBUILD_CFLAGS += $(call cc-option,-Oz,-Os)
685 ifdef CONFIG_CC_DISABLE_WARN_MAYBE_UNINITIALIZED
686 KBUILD_CFLAGS += -Wno-maybe-uninitialized
689 # Tell gcc to never replace conditional load with a non-conditional one
690 KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
692 include scripts/Makefile.kcov
693 include scripts/Makefile.gcc-plugins
695 ifdef CONFIG_READABLE_ASM
696 # Disable optimizations that make assembler listings hard to read.
697 # reorder blocks reorders the control in the function
698 # ipa clone creates specialized cloned functions
699 # partial inlining inlines only parts of functions
700 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
701 $(call cc-option,-fno-ipa-cp-clone,) \
702 $(call cc-option,-fno-partial-inlining)
705 ifneq ($(CONFIG_FRAME_WARN),0)
706 KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
709 stackp-flags-$(CONFIG_CC_HAS_STACKPROTECTOR_NONE) := -fno-stack-protector
710 stackp-flags-$(CONFIG_STACKPROTECTOR) := -fstack-protector
711 stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong
713 KBUILD_CFLAGS += $(stackp-flags-y)
715 ifdef CONFIG_CC_IS_CLANG
716 KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
717 KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
718 KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
719 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
720 # Quiet clang warning: comparison of unsigned expression < 0 is always false
721 KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
722 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
723 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
724 # See modpost pattern 2
725 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
726 KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
729 # These warnings generated too much noise in a regular build.
730 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
731 KBUILD_CFLAGS += -Wno-unused-but-set-variable
734 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
735 ifdef CONFIG_FRAME_POINTER
736 KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
738 # Some targets (ARM with Thumb2, for example), can't be built with frame
739 # pointers. For those, we don't have FUNCTION_TRACER automatically
740 # select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
741 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
742 # -fomit-frame-pointer with FUNCTION_TRACER.
743 ifndef CONFIG_FUNCTION_TRACER
744 KBUILD_CFLAGS += -fomit-frame-pointer
748 DEBUG_CFLAGS := $(call cc-option, -fno-var-tracking-assignments)
750 ifdef CONFIG_DEBUG_INFO
751 ifdef CONFIG_DEBUG_INFO_SPLIT
752 DEBUG_CFLAGS += -gsplit-dwarf
756 KBUILD_AFLAGS += -Wa,-gdwarf-2
758 ifdef CONFIG_DEBUG_INFO_DWARF4
759 DEBUG_CFLAGS += -gdwarf-4
762 ifdef CONFIG_DEBUG_INFO_REDUCED
763 DEBUG_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
764 $(call cc-option,-fno-var-tracking)
767 KBUILD_CFLAGS += $(DEBUG_CFLAGS)
770 ifdef CONFIG_FUNCTION_TRACER
771 ifdef CONFIG_FTRACE_MCOUNT_RECORD
772 # gcc 5 supports generating the mcount tables directly
773 ifeq ($(call cc-option-yn,-mrecord-mcount),y)
774 CC_FLAGS_FTRACE += -mrecord-mcount
775 export CC_USING_RECORD_MCOUNT := 1
777 ifdef CONFIG_HAVE_NOP_MCOUNT
778 ifeq ($(call cc-option-yn, -mnop-mcount),y)
779 CC_FLAGS_FTRACE += -mnop-mcount
780 CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
784 ifdef CONFIG_HAVE_FENTRY
785 ifeq ($(call cc-option-yn, -mfentry),y)
786 CC_FLAGS_FTRACE += -mfentry
787 CC_FLAGS_USING += -DCC_USING_FENTRY
790 export CC_FLAGS_FTRACE
791 KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
792 KBUILD_AFLAGS += $(CC_FLAGS_USING)
793 ifdef CONFIG_DYNAMIC_FTRACE
794 ifdef CONFIG_HAVE_C_RECORDMCOUNT
795 BUILD_C_RECORDMCOUNT := y
796 export BUILD_C_RECORDMCOUNT
801 # We trigger additional mismatches with less inlining
802 ifdef CONFIG_DEBUG_SECTION_MISMATCH
803 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
806 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
807 KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
808 LDFLAGS_vmlinux += --gc-sections
811 # arch Makefile may override CC so keep this after arch Makefile is included
812 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
814 # warn about C99 declaration after statement
815 KBUILD_CFLAGS += -Wdeclaration-after-statement
817 # Variable Length Arrays (VLAs) should not be used anywhere in the kernel
818 KBUILD_CFLAGS += $(call cc-option,-Wvla)
820 # disable pointer signed / unsigned warnings in gcc 4.0
821 KBUILD_CFLAGS += -Wno-pointer-sign
823 # disable stringop warnings in gcc 8+
824 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
826 # disable invalid "can't wrap" optimizations for signed / pointers
827 KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
829 # clang sets -fmerge-all-constants by default as optimization, but this
830 # is non-conforming behavior for C and in fact breaks the kernel, so we
831 # need to disable it here generally.
832 KBUILD_CFLAGS += $(call cc-option,-fno-merge-all-constants)
834 # for gcc -fno-merge-all-constants disables everything, but it is fine
835 # to have actual conforming behavior enabled.
836 KBUILD_CFLAGS += $(call cc-option,-fmerge-constants)
838 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
839 KBUILD_CFLAGS += $(call cc-option,-fno-stack-check,)
841 # conserve stack if available
842 KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
844 # Prohibit date/time macros, which would make the build non-deterministic
845 KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
847 # enforce correct pointer usage
848 KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
850 # Require designated initializers for all marked structures
851 KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
853 # change __FILE__ to the relative path from the srctree
854 KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
856 # use the deterministic mode of AR if available
857 KBUILD_ARFLAGS := $(call ar-option,D)
859 include scripts/Makefile.kasan
860 include scripts/Makefile.extrawarn
861 include scripts/Makefile.ubsan
863 # Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
865 KBUILD_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS)
866 KBUILD_AFLAGS += $(ARCH_AFLAGS) $(KAFLAGS)
867 KBUILD_CFLAGS += $(ARCH_CFLAGS) $(KCFLAGS)
869 # Use --build-id when available.
870 LDFLAGS_BUILD_ID := $(call ld-option, --build-id)
871 KBUILD_LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
872 LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
874 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
875 LDFLAGS_vmlinux += $(call ld-option, -X,)
878 # insure the checker run with the right endianness
879 CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
881 # the checker needs the correct machine size
882 CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
884 # Default kernel image to build when no specific target is given.
885 # KBUILD_IMAGE may be overruled on the command line or
886 # set in the environment
887 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
889 export KBUILD_IMAGE ?= vmlinux
892 # INSTALL_PATH specifies where to place the updated kernel and system map
893 # images. Default is /boot, but you can set it to other values
894 export INSTALL_PATH ?= /boot
897 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
898 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
899 # an argument if needed. Otherwise it defaults to the kernel install path
901 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
904 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
905 # relocations required by build roots. This is not defined in the
906 # makefile but the argument can be passed to make if needed.
909 MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
913 # INSTALL_MOD_STRIP, if defined, will cause modules to be
914 # stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
915 # the default option --strip-debug will be used. Otherwise,
916 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
918 ifdef INSTALL_MOD_STRIP
919 ifeq ($(INSTALL_MOD_STRIP),1)
920 mod_strip_cmd = $(STRIP) --strip-debug
922 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
923 endif # INSTALL_MOD_STRIP=1
926 endif # INSTALL_MOD_STRIP
929 # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
930 # after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
931 # or CONFIG_MODULE_COMPRESS_XZ.
933 mod_compress_cmd = true
934 ifdef CONFIG_MODULE_COMPRESS
935 ifdef CONFIG_MODULE_COMPRESS_GZIP
936 mod_compress_cmd = gzip -n -f
937 endif # CONFIG_MODULE_COMPRESS_GZIP
938 ifdef CONFIG_MODULE_COMPRESS_XZ
939 mod_compress_cmd = xz -f
940 endif # CONFIG_MODULE_COMPRESS_XZ
941 endif # CONFIG_MODULE_COMPRESS
942 export mod_compress_cmd
944 ifdef CONFIG_MODULE_SIG_ALL
945 $(eval $(call config_filename,MODULE_SIG_KEY))
947 mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
953 ifdef CONFIG_STACK_VALIDATION
954 has_libelf := $(call try-run,\
955 echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0)
956 ifeq ($(has_libelf),1)
957 objtool_target := tools/objtool FORCE
959 SKIP_STACK_VALIDATION := 1
960 export SKIP_STACK_VALIDATION
966 ifeq ($(KBUILD_EXTMOD),)
967 core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
969 vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
970 $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
971 $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
973 vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
974 $(init-) $(core-) $(drivers-) $(net-) $(libs-) $(virt-))))
976 init-y := $(patsubst %/, %/built-in.a, $(init-y))
977 core-y := $(patsubst %/, %/built-in.a, $(core-y))
978 drivers-y := $(patsubst %/, %/built-in.a, $(drivers-y))
979 net-y := $(patsubst %/, %/built-in.a, $(net-y))
980 libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
981 libs-y2 := $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y)))
982 virt-y := $(patsubst %/, %/built-in.a, $(virt-y))
984 # Externally visible symbols (used by link-vmlinux.sh)
985 export KBUILD_VMLINUX_OBJS := $(head-y) $(init-y) $(core-y) $(libs-y2) \
986 $(drivers-y) $(net-y) $(virt-y)
987 export KBUILD_VMLINUX_LIBS := $(libs-y1)
988 export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
989 export LDFLAGS_vmlinux
990 # used by scripts/package/Makefile
991 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools)
993 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
995 # Recurse until adjust_autoksyms.sh is satisfied
996 PHONY += autoksyms_recursive
997 autoksyms_recursive: $(vmlinux-deps)
998 ifdef CONFIG_TRIM_UNUSED_KSYMS
999 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1000 "$(MAKE) -f $(srctree)/Makefile vmlinux"
1003 # For the kernel to actually contain only the needed exported symbols,
1004 # we have to build modules as well to determine what those symbols are.
1005 # (this can be evaluated only once include/config/auto.conf has been included)
1006 ifdef CONFIG_TRIM_UNUSED_KSYMS
1010 autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1013 $(Q)mkdir -p $(dir $@)
1016 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1018 # Final link of vmlinux with optional arch pass after final link
1019 cmd_link-vmlinux = \
1020 $(CONFIG_SHELL) $< $(LD) $(KBUILD_LDFLAGS) $(LDFLAGS_vmlinux) ; \
1021 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1023 vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1024 +$(call if_changed,link-vmlinux)
1028 # Build samples along the rest of the kernel. This needs headers_install.
1029 ifdef CONFIG_SAMPLES
1030 vmlinux-dirs += samples
1031 samples: headers_install
1034 # The actual objects are generated when descending,
1035 # make sure no implicit rule kicks in
1036 $(sort $(vmlinux-deps)): $(vmlinux-dirs) ;
1038 # Handle descending into subdirectories listed in $(vmlinux-dirs)
1039 # Preset locale variables to speed up the build process. Limit locale
1040 # tweaks to this spot to avoid wrong language settings when running
1041 # make menuconfig etc.
1042 # Error messages still appears in the original language
1044 PHONY += $(vmlinux-dirs)
1045 $(vmlinux-dirs): prepare
1046 $(Q)$(MAKE) $(build)=$@ need-builtin=1
1048 filechk_kernel.release = \
1049 echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1051 # Store (new) KERNELRELEASE string in include/config/kernel.release
1052 include/config/kernel.release: $(srctree)/Makefile FORCE
1053 $(call filechk,kernel.release)
1055 # Additional helpers built in scripts/
1056 # Carefully list dependencies so we do not try to build scripts twice
1059 scripts: scripts_basic scripts_dtc
1060 $(Q)$(MAKE) $(build)=$(@)
1062 # Things we need to do before we recursively start building the kernel
1063 # or the modules are listed in "prepare".
1064 # A multi level approach is used. prepareN is processed before prepareN-1.
1065 # archprepare is used in arch Makefiles and when processed asm symlink,
1066 # version.h and scripts_basic is processed / created.
1068 PHONY += prepare archprepare prepare1 prepare3
1070 # prepare3 is used to check if we are building in a separate output directory,
1072 # 1) Check that make has not been executed in the kernel src $(srctree)
1073 prepare3: include/config/kernel.release
1074 ifneq ($(KBUILD_SRC),)
1075 @$(kecho) ' Using $(srctree) as source for kernel'
1076 $(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
1077 echo >&2 " $(srctree) is not clean, please run 'make mrproper'"; \
1078 echo >&2 " in the '$(srctree)' directory.";\
1083 prepare1: prepare3 outputmakefile asm-generic $(version_h) $(autoksyms_h) \
1084 include/generated/utsrelease.h
1087 archprepare: archheaders archscripts prepare1 scripts
1089 prepare0: archprepare
1090 $(Q)$(MAKE) $(build)=scripts/mod
1091 $(Q)$(MAKE) $(build)=.
1093 # All the preparing..
1094 prepare: prepare0 prepare-objtool
1096 # Support for using generic headers in asm-generic
1097 asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1099 PHONY += asm-generic uapi-asm-generic
1100 asm-generic: uapi-asm-generic
1101 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1102 generic=include/asm-generic
1104 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1105 generic=include/uapi/asm-generic
1107 PHONY += prepare-objtool
1108 prepare-objtool: $(objtool_target)
1109 ifeq ($(SKIP_STACK_VALIDATION),1)
1110 ifdef CONFIG_UNWINDER_ORC
1111 @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1114 @echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1118 # Generate some files
1119 # ---------------------------------------------------------------------------
1121 # KERNELRELEASE can change from a few different places, meaning version.h
1122 # needs to be updated, so this check is forced on all builds
1125 define filechk_utsrelease.h
1126 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1127 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1130 echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1133 define filechk_version.h
1134 echo \#define LINUX_VERSION_CODE $(shell \
1135 expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
1136 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))'
1140 $(call filechk,version.h)
1141 $(Q)rm -f $(old_version_h)
1143 include/generated/utsrelease.h: include/config/kernel.release FORCE
1144 $(call filechk,utsrelease.h)
1148 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1149 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1151 # ---------------------------------------------------------------------------
1154 #Default location for installed headers
1155 export INSTALL_HDR_PATH = $(objtree)/usr
1157 # If we do an all arch process set dst to include/arch-$(SRCARCH)
1158 hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(SRCARCH), dst=include)
1160 PHONY += archheaders archscripts
1163 __headers: $(version_h) scripts_basic uapi-asm-generic archheaders archscripts
1164 $(Q)$(MAKE) $(build)=scripts build_unifdef
1166 PHONY += headers_install_all
1167 headers_install_all:
1168 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh install
1170 PHONY += headers_install
1171 headers_install: __headers
1172 $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1173 $(error Headers not exportable for the $(SRCARCH) architecture))
1174 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include
1175 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst)
1177 PHONY += headers_check_all
1178 headers_check_all: headers_install_all
1179 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh check
1181 PHONY += headers_check
1182 headers_check: headers_install
1183 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include HDRCHECK=1
1184 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst) HDRCHECK=1
1186 ifdef CONFIG_HEADERS_CHECK
1190 # ---------------------------------------------------------------------------
1195 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1197 PHONY += kselftest-clean
1199 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests clean
1201 PHONY += kselftest-merge
1203 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1204 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \
1205 -m $(objtree)/.config \
1206 $(srctree)/tools/testing/selftests/*/config
1207 +$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1209 # ---------------------------------------------------------------------------
1212 ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1213 dtstree := arch/$(SRCARCH)/boot/dts
1218 %.dtb: prepare3 scripts_dtc
1219 $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1221 PHONY += dtbs dtbs_install dt_binding_check
1222 dtbs dtbs_check: prepare3 scripts_dtc
1223 $(Q)$(MAKE) $(build)=$(dtstree)
1225 dtbs_check: export CHECK_DTBS=1
1226 dtbs_check: dt_binding_check
1229 $(Q)$(MAKE) $(dtbinst)=$(dtstree)
1231 ifdef CONFIG_OF_EARLY_FLATTREE
1237 PHONY += scripts_dtc
1238 scripts_dtc: scripts_basic
1239 $(Q)$(MAKE) $(build)=scripts/dtc
1241 dt_binding_check: scripts_dtc
1242 $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1244 # ---------------------------------------------------------------------------
1247 ifdef CONFIG_MODULES
1249 # By default, build modules as well
1255 # A module can be listed more than once in obj-m resulting in
1256 # duplicate lines in modules.order files. Those are removed
1257 # using awk while concatenating to the final file.
1260 modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
1261 $(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
1262 @$(kecho) ' Building modules, stage 2.';
1263 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1265 modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
1266 $(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
1268 %/modules.builtin: include/config/auto.conf include/config/tristate.conf
1269 $(Q)$(MAKE) $(modbuiltin)=$*
1272 # Target to prepare building external modules
1273 PHONY += modules_prepare
1274 modules_prepare: prepare
1276 # Target to install modules
1277 PHONY += modules_install
1278 modules_install: _modinst_ _modinst_post
1282 @rm -rf $(MODLIB)/kernel
1283 @rm -f $(MODLIB)/source
1284 @mkdir -p $(MODLIB)/kernel
1285 @ln -s $(abspath $(srctree)) $(MODLIB)/source
1286 @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
1287 rm -f $(MODLIB)/build ; \
1288 ln -s $(CURDIR) $(MODLIB)/build ; \
1290 @cp -f $(objtree)/modules.order $(MODLIB)/
1291 @cp -f $(objtree)/modules.builtin $(MODLIB)/
1292 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1294 # This depmod is only for convenience to give the initial
1295 # boot a modules.dep even before / is mounted read-write. However the
1296 # boot script depmod is the master version.
1297 PHONY += _modinst_post
1298 _modinst_post: _modinst_
1301 ifeq ($(CONFIG_MODULE_SIG), y)
1302 PHONY += modules_sign
1304 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1307 else # CONFIG_MODULES
1309 # Modules not configured
1310 # ---------------------------------------------------------------------------
1312 PHONY += modules modules_install
1313 modules modules_install:
1315 @echo >&2 "The present kernel configuration has modules disabled."
1316 @echo >&2 "Type 'make config' and enable loadable module support."
1317 @echo >&2 "Then build a kernel with module support enabled."
1321 endif # CONFIG_MODULES
1324 # Cleaning is done on three levels.
1325 # make clean Delete most generated files
1326 # Leave enough to build external modules
1327 # make mrproper Delete the current configuration, and all generated files
1328 # make distclean Remove editor backup files, patch leftover files and the like
1330 # Directories & files removed with 'make clean'
1331 CLEAN_DIRS += $(MODVERDIR) include/ksym
1333 # Directories & files removed with 'make mrproper'
1334 MRPROPER_DIRS += include/config usr/include include/generated \
1335 arch/*/include/generated .tmp_objdiff
1336 MRPROPER_FILES += .config .config.old .version \
1337 Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
1338 signing_key.pem signing_key.priv signing_key.x509 \
1339 x509.genkey extra_certificates signing_key.x509.keyid \
1340 signing_key.x509.signer vmlinux-gdb.py
1342 # clean - Delete most, but leave enough to build external modules
1344 clean: rm-dirs := $(CLEAN_DIRS)
1345 clean: rm-files := $(CLEAN_FILES)
1346 clean-dirs := $(addprefix _clean_, . $(vmlinux-alldirs) Documentation samples)
1348 PHONY += $(clean-dirs) clean archclean vmlinuxclean
1350 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1353 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1354 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1356 clean: archclean vmlinuxclean
1358 # mrproper - Delete all generated files, including .config
1360 mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS))
1361 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1362 mrproper-dirs := $(addprefix _mrproper_,scripts)
1364 PHONY += $(mrproper-dirs) mrproper
1366 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1368 mrproper: clean $(mrproper-dirs)
1377 @find $(srctree) $(RCS_FIND_IGNORE) \
1378 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1379 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1380 -o -name 'core' \) \
1381 -type f -print | xargs rm -f
1384 # Packaging of the kernel to various formats
1385 # ---------------------------------------------------------------------------
1386 package-dir := scripts/package
1389 $(Q)$(MAKE) $(build)=$(package-dir) $@
1390 %pkg: include/config/kernel.release FORCE
1391 $(Q)$(MAKE) $(build)=$(package-dir) $@
1394 # Brief documentation of the typical targets used
1395 # ---------------------------------------------------------------------------
1397 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1398 boards := $(sort $(notdir $(boards)))
1399 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1400 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1404 @echo 'Cleaning targets:'
1405 @echo ' clean - Remove most generated files but keep the config and'
1406 @echo ' enough build support to build external modules'
1407 @echo ' mrproper - Remove all generated files + config + various backup files'
1408 @echo ' distclean - mrproper + remove editor backup and patch files'
1410 @echo 'Configuration targets:'
1411 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1413 @echo 'Other generic targets:'
1414 @echo ' all - Build all targets marked with [*]'
1415 @echo '* vmlinux - Build the bare kernel'
1416 @echo '* modules - Build all modules'
1417 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1418 @echo ' dir/ - Build all files in dir and below'
1419 @echo ' dir/file.[ois] - Build specified target only'
1420 @echo ' dir/file.ll - Build the LLVM assembly file'
1421 @echo ' (requires compiler support for LLVM assembly generation)'
1422 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1423 @echo ' (requires a recent binutils and recent build (System.map))'
1424 @echo ' dir/file.ko - Build module including final link'
1425 @echo ' modules_prepare - Set up for building external modules'
1426 @echo ' tags/TAGS - Generate tags file for editors'
1427 @echo ' cscope - Generate cscope index'
1428 @echo ' gtags - Generate GNU GLOBAL index'
1429 @echo ' kernelrelease - Output the release version string (use with make -s)'
1430 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1431 @echo ' image_name - Output the image name (use with make -s)'
1432 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1433 echo ' (default: $(INSTALL_HDR_PATH))'; \
1435 @echo 'Static analysers:'
1436 @echo ' checkstack - Generate a list of stack hogs'
1437 @echo ' namespacecheck - Name space analysis on compiled kernel'
1438 @echo ' versioncheck - Sanity check on version.h usage'
1439 @echo ' includecheck - Check for duplicate included header files'
1440 @echo ' export_report - List the usages of all exported symbols'
1441 @echo ' headers_check - Sanity check on exported headers'
1442 @echo ' headerdep - Detect inclusion cycles in headers'
1443 @echo ' coccicheck - Check with Coccinelle'
1445 @echo 'Kernel selftest:'
1446 @echo ' kselftest - Build and run kernel selftest (run as root)'
1447 @echo ' Build, install, and boot kernel before'
1448 @echo ' running kselftest on it'
1449 @echo ' kselftest-clean - Remove all generated kselftest files'
1450 @echo ' kselftest-merge - Merge all the config dependencies of kselftest to existing'
1454 echo 'Devicetree:'; \
1455 echo '* dtbs - Build device tree blobs for enabled boards'; \
1456 echo ' dtbs_install - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1459 @echo 'Userspace tools targets:'
1460 @echo ' use "make tools/help"'
1461 @echo ' or "cd tools; make help"'
1463 @echo 'Kernel packaging:'
1464 @$(MAKE) $(build)=$(package-dir) help
1466 @echo 'Documentation targets:'
1467 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1469 @echo 'Architecture specific targets ($(SRCARCH)):'
1470 @$(if $(archhelp),$(archhelp),\
1471 echo ' No architecture specific help defined for $(SRCARCH)')
1474 $(foreach b, $(boards), \
1475 printf " %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1477 @$(if $(board-dirs), \
1478 $(foreach b, $(board-dirs), \
1479 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1480 printf " %-16s - Show all of the above\\n" help-boards; \
1483 @echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1484 @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
1485 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1486 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK (sparse by default)'
1487 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1488 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1489 @echo ' make W=n [targets] Enable extra gcc checks, n=1,2,3 where'
1490 @echo ' 1: warnings which may be relevant and do not occur too often'
1491 @echo ' 2: warnings which occur quite often but may still be relevant'
1492 @echo ' 3: more obscure warnings, can most likely be ignored'
1493 @echo ' Multiple levels can be combined with W=12 or W=123'
1495 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1496 @echo 'For further info see the ./README file'
1499 help-board-dirs := $(addprefix help-,$(board-dirs))
1501 help-boards: $(help-board-dirs)
1503 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1505 $(help-board-dirs): help-%:
1506 @echo 'Architecture specific targets ($(SRCARCH) $*):'
1507 @$(if $(boards-per-dir), \
1508 $(foreach b, $(boards-per-dir), \
1509 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1513 # Documentation targets
1514 # ---------------------------------------------------------------------------
1515 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1516 linkcheckdocs dochelp refcheckdocs
1517 PHONY += $(DOC_TARGETS)
1518 $(DOC_TARGETS): scripts_basic FORCE
1519 $(Q)$(MAKE) $(build)=Documentation $@
1522 # ---------------------------------------------------------------------------
1524 PHONY += scripts_gdb
1525 scripts_gdb: prepare
1526 $(Q)$(MAKE) $(build)=scripts/gdb
1527 $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1529 ifdef CONFIG_GDB_SCRIPTS
1533 else # KBUILD_EXTMOD
1536 # External module support.
1537 # When building external modules the kernel used as basis is considered
1538 # read-only, and no consistency checks are made and the make
1539 # system is not used on the basis kernel. If updates are required
1540 # in the basis kernel ordinary make commands (without M=...) must
1543 # The following are the only valid targets when building external
1545 # make M=dir clean Delete all automatically generated files
1546 # make M=dir modules Make all modules in specified dir
1547 # make M=dir Same as 'make M=dir modules'
1548 # make M=dir modules_install
1549 # Install the modules built in the module directory
1550 # Assumes install directory is already created
1552 # We are always building modules
1555 PHONY += $(objtree)/Module.symvers
1556 $(objtree)/Module.symvers:
1557 @test -e $(objtree)/Module.symvers || ( \
1559 echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1560 echo " is missing; modules will have no dependencies and modversions."; \
1563 module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
1564 PHONY += $(module-dirs) modules
1565 $(module-dirs): prepare $(objtree)/Module.symvers
1566 $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
1568 modules: $(module-dirs)
1569 @$(kecho) ' Building modules, stage 2.';
1570 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1572 PHONY += modules_install
1573 modules_install: _emodinst_ _emodinst_post
1575 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1578 $(Q)mkdir -p $(MODLIB)/$(install-dir)
1579 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1581 PHONY += _emodinst_post
1582 _emodinst_post: _emodinst_
1585 clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))
1587 PHONY += $(clean-dirs) clean
1589 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1591 clean: rm-dirs := $(MODVERDIR)
1592 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1596 @echo ' Building external modules.'
1597 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1599 @echo ' modules - default target, build the module(s)'
1600 @echo ' modules_install - install the module'
1601 @echo ' clean - remove generated files in module directory only'
1607 endif # KBUILD_EXTMOD
1609 clean: $(clean-dirs)
1612 @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1613 \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1615 -o -name '*.dtb' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1616 -o -name '*.dwo' -o -name '*.lst' \
1618 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1619 -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1620 -o -name '*.asn1.[ch]' \
1621 -o -name '*.symtypes' -o -name 'modules.order' \
1622 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1623 -o -name '*.c.[012]*.*' \
1625 -o -name '*.gcno' \) -type f -print | xargs rm -f
1627 # Generate tags for editors
1628 # ---------------------------------------------------------------------------
1629 quiet_cmd_tags = GEN $@
1630 cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
1632 tags TAGS cscope gtags: FORCE
1635 # Scripts to check various things for consistency
1636 # ---------------------------------------------------------------------------
1638 PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1641 find $(srctree)/* $(RCS_FIND_IGNORE) \
1642 -name '*.[hcS]' -type f -print | sort \
1643 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1646 find $(srctree)/* $(RCS_FIND_IGNORE) \
1647 -name '*.[hcS]' -type f -print | sort \
1648 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1651 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1654 $(PERL) $(srctree)/scripts/namespace.pl
1657 $(PERL) $(srctree)/scripts/export_report.pl
1659 PHONY += checkstack kernelrelease kernelversion image_name
1661 # UML needs a little special treatment here. It wants to use the host
1662 # toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
1663 # else wants $(ARCH), including people doing cross-builds, which means
1664 # that $(SUBARCH) doesn't work here.
1666 CHECKSTACK_ARCH := $(SUBARCH)
1668 CHECKSTACK_ARCH := $(ARCH)
1671 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1672 $(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1675 @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1678 @echo $(KERNELVERSION)
1681 @echo $(KBUILD_IMAGE)
1683 # Clear a bunch of variables before executing the submake
1685 ifeq ($(quiet),silent_)
1690 $(Q)mkdir -p $(objtree)/tools
1691 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/
1694 $(Q)mkdir -p $(objtree)/tools
1695 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/ $*
1698 # ---------------------------------------------------------------------------
1699 # Single targets are compatible with:
1700 # - build with mixed source and output
1701 # - build with separate output dir 'make O=...'
1702 # - external modules
1704 # target-dir => where to store outputfile
1705 # build-dir => directory in kernel source tree to use
1707 build-target = $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD)/)$@
1708 build-dir = $(patsubst %/,%,$(dir $(build-target)))
1711 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1713 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1714 %.lst: prepare FORCE
1715 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1717 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1719 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1720 %.symtypes: prepare FORCE
1721 $(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
1723 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1729 # Make sure the latest headers are built for Documentation
1730 Documentation/ samples/: headers_install
1732 $(Q)$(MAKE) KBUILD_MODULES=1 $(build)=$(build-dir)
1734 # FIXME Should go into a make.lib or something
1735 # ===========================================================================
1737 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs)))
1738 cmd_rmdirs = rm -rf $(rm-dirs)
1740 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
1741 cmd_rmfiles = rm -f $(rm-files)
1743 # Run depmod only if we have System.map and depmod is executable
1744 quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
1745 cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1748 # Create temporary dir for module support files
1749 # clean it up only when building all modules
1750 cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
1751 $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
1753 # read saved command lines for existing targets
1754 existing-targets := $(wildcard $(sort $(targets)))
1756 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1758 endif # ifeq ($(config-targets),1)
1759 endif # ifeq ($(mixed-targets),1)
1760 endif # sub-make-done
1765 # Declare the contents of the PHONY variable as phony. We keep that
1766 # information in a variable so we can use it in if_changed and friends.