1 # SPDX-License-Identifier: GPL-2.0
9 # To see a list of typical targets execute "make help"
10 # More info can be located in ./README
11 # Comments in this file are targeted only to the developer, do not
12 # expect to learn how to build the kernel reading this file.
14 # That's our default target when none is given on the command line
18 # Do not use make's built-in rules and variables
19 # (this increases performance and avoids hard-to-debug behaviour)
22 # Avoid funny character set dependencies
26 export LC_COLLATE LC_NUMERIC
28 # Avoid interference with shell env settings
31 # We are using a recursive build, so we need to do a little thinking
32 # to get the ordering right.
34 # Most importantly: sub-Makefiles should only ever modify files in
35 # their own directory. If in some directory we have a dependency on
36 # a file in another dir (which doesn't happen often, but it's often
37 # unavoidable when linking the built-in.a targets which finally
38 # turn into vmlinux), we will call a sub make in that other dir, and
39 # after that we are sure that everything which is in that other dir
42 # The only cases where we need to modify files which have global
43 # effects are thus separated out and done before the recursive
44 # descending is started. They are now explicitly listed as the
48 # ---------------------------------------------------------------------------
50 # Normally, we echo the whole command before executing it. By making
51 # that echo $($(quiet)$(cmd)), we now have the possibility to set
52 # $(quiet) to choose other forms of output instead, e.g.
54 # quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
55 # cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
57 # If $(quiet) is empty, the whole command will be printed.
58 # If it is set to "quiet_", only the short version will be printed.
59 # If it is set to "silent_", nothing will be printed at all, since
60 # the variable $(silent_cmd_cc_o_c) doesn't exist.
62 # A simple variant is to prefix commands with $(Q) - that's useful
63 # for commands that shall be hidden in non-verbose mode.
67 # If KBUILD_VERBOSE equals 0 then the above command will be hidden.
68 # If KBUILD_VERBOSE equals 1 then the above command is displayed.
70 # To put more focus on warnings, be less verbose as default
71 # Use 'make V=1' to see the full commands
73 ifeq ("$(origin V)", "command line")
80 ifeq ($(KBUILD_VERBOSE),1)
88 # If the user is running make -s (silent mode), suppress echoing of
91 ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
96 export quiet Q KBUILD_VERBOSE
98 # kbuild supports saving output files in a separate directory.
99 # To locate output files in a separate directory two syntaxes are supported.
100 # In both cases the working directory must be the root of the kernel src.
102 # Use "make O=dir/to/store/output/files/"
104 # 2) Set KBUILD_OUTPUT
105 # Set the environment variable KBUILD_OUTPUT to point to the directory
106 # where the output files shall be placed.
107 # export KBUILD_OUTPUT=dir/to/store/output/files/
110 # The O= assignment takes precedence over the KBUILD_OUTPUT environment
113 # KBUILD_SRC is not intended to be used by the regular user (for now),
114 # it is set on invocation of make with KBUILD_OUTPUT or O= specified.
115 ifeq ($(KBUILD_SRC),)
117 # OK, Make called in directory where kernel src resides
118 # Do we want to locate output files in a separate directory?
119 ifeq ("$(origin O)", "command line")
120 KBUILD_OUTPUT := $(O)
123 # Cancel implicit rules on top Makefile
124 $(CURDIR)/Makefile Makefile: ;
126 ifneq ($(words $(subst :, ,$(CURDIR))), 1)
127 $(error main directory cannot contain spaces nor colons)
130 ifneq ($(KBUILD_OUTPUT),)
131 # check that the output directory actually exists
132 saved-output := $(KBUILD_OUTPUT)
133 KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
135 $(if $(KBUILD_OUTPUT),, \
136 $(error failed to create output directory "$(saved-output)"))
138 # Look for make include files relative to root of kernel src
140 # This does not become effective immediately because MAKEFLAGS is re-parsed
141 # once after the Makefile is read. It is OK since we are going to invoke
143 MAKEFLAGS += --include-dir=$(CURDIR)
145 PHONY += $(MAKECMDGOALS) sub-make
147 $(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
150 # Invoke a second make in the output directory, passing relevant variables
152 $(Q)$(MAKE) -C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR) \
153 -f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS))
155 # Leave processing to above invocation of make
157 endif # ifneq ($(KBUILD_OUTPUT),)
158 endif # ifeq ($(KBUILD_SRC),)
160 # We process the rest of the Makefile if this is the final invocation of make
161 ifeq ($(skip-makefile),)
163 # Do not print "Entering directory ...",
164 # but we want to display it when entering to the output directory
165 # so that IDEs/editors are able to understand relative filenames.
166 MAKEFLAGS += --no-print-directory
168 # Call a source code checker (by default, "sparse") as part of the
171 # Use 'make C=1' to enable checking of only re-compiled files.
172 # Use 'make C=2' to enable checking of *all* source files, regardless
173 # of whether they are re-compiled or not.
175 # See the file "Documentation/dev-tools/sparse.rst" for more details,
176 # including where to get the "sparse" utility.
178 ifeq ("$(origin C)", "command line")
179 KBUILD_CHECKSRC = $(C)
181 ifndef KBUILD_CHECKSRC
185 # Use make M=dir to specify directory of external module to build
186 # Old syntax make ... SUBDIRS=$PWD is still supported
187 # Setting the environment variable KBUILD_EXTMOD take precedence
189 $(warning ================= WARNING ================)
190 $(warning 'SUBDIRS' will be removed after Linux 5.3)
191 $(warning Please use 'M=' or 'KBUILD_EXTMOD' instead)
192 $(warning ==========================================)
193 KBUILD_EXTMOD ?= $(SUBDIRS)
196 ifeq ("$(origin M)", "command line")
197 KBUILD_EXTMOD := $(M)
200 ifeq ($(KBUILD_SRC),)
201 # building in the source tree
204 ifeq ($(KBUILD_SRC)/,$(dir $(CURDIR)))
205 # building in a subdirectory of the source tree
208 srctree := $(KBUILD_SRC)
212 export KBUILD_CHECKSRC KBUILD_EXTMOD KBUILD_SRC
218 VPATH := $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))
220 export srctree objtree VPATH
222 # To make sure we do not include .config for any of the *config targets
223 # catch them early, and hand them over to scripts/kconfig/Makefile
224 # It is allowed to specify more targets when calling make, including
225 # mixing *config targets and build targets.
226 # For example 'make oldconfig all'.
227 # Detect when mixed targets is specified, and make a second invocation
228 # of make so .config is not included in this case either (for *config).
230 version_h := include/generated/uapi/linux/version.h
231 old_version_h := include/linux/version.h
233 clean-targets := %clean mrproper cleandocs
234 no-dot-config-targets := $(clean-targets) \
235 cscope gtags TAGS tags help% %docs check% coccicheck \
236 $(version_h) headers_% archheaders archscripts \
237 %asm-generic kernelversion %src-pkg
238 no-sync-config-targets := $(no-dot-config-targets) install %install \
246 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
247 ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
252 ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
253 ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
258 ifneq ($(KBUILD_EXTMOD),)
262 ifeq ($(KBUILD_EXTMOD),)
263 ifneq ($(filter config %config,$(MAKECMDGOALS)),)
265 ifneq ($(words $(MAKECMDGOALS)),1)
271 # For "make -j clean all", "make -j mrproper defconfig all", etc.
272 ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
273 ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
278 # install and modules_install need also be processed one by one
279 ifneq ($(filter install,$(MAKECMDGOALS)),)
280 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
285 ifeq ($(mixed-targets),1)
286 # ===========================================================================
287 # We're called with mixed targets (*config and build targets).
288 # Handle them one by one.
290 PHONY += $(MAKECMDGOALS) __build_one_by_one
292 $(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
297 for i in $(MAKECMDGOALS); do \
298 $(MAKE) -f $(srctree)/Makefile $$i; \
303 # We need some generic definitions (do not try to remake the file).
304 scripts/Kbuild.include: ;
305 include scripts/Kbuild.include
307 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
308 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
309 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
310 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
312 include scripts/subarch.include
314 # Cross compiling and selecting different set of gcc/bin-utils
315 # ---------------------------------------------------------------------------
317 # When performing cross compilation for other architectures ARCH shall be set
318 # to the target architecture. (See arch/* for the possibilities).
319 # ARCH can be set during invocation of make:
321 # Another way is to have ARCH set in the environment.
322 # The default ARCH is the host where make is executed.
324 # CROSS_COMPILE specify the prefix used for all executables used
325 # during compilation. Only gcc and related bin-utils executables
326 # are prefixed with $(CROSS_COMPILE).
327 # CROSS_COMPILE can be set on the command line
328 # make CROSS_COMPILE=ia64-linux-
329 # Alternatively CROSS_COMPILE can be set in the environment.
330 # Default value for CROSS_COMPILE is not to prefix executables
331 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
334 # Architecture as present in compile.h
335 UTS_MACHINE := $(ARCH)
338 # Additional ARCH settings for x86
342 ifeq ($(ARCH),x86_64)
346 # Additional ARCH settings for sparc
347 ifeq ($(ARCH),sparc32)
350 ifeq ($(ARCH),sparc64)
354 # Additional ARCH settings for sh
359 KCONFIG_CONFIG ?= .config
360 export KCONFIG_CONFIG
362 # SHELL used by kbuild
363 CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
364 else if [ -x /bin/bash ]; then echo /bin/bash; \
365 else echo sh; fi ; fi)
367 HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
368 HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
369 HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
373 KBUILD_HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 \
374 -fomit-frame-pointer -std=gnu89 $(HOST_LFS_CFLAGS) \
376 KBUILD_HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
377 KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
378 KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
380 # Make variables (CC, etc...)
381 AS = $(CROSS_COMPILE)as
382 LD = $(CROSS_COMPILE)ld
383 CC = $(CROSS_COMPILE)gcc
385 AR = $(CROSS_COMPILE)ar
386 NM = $(CROSS_COMPILE)nm
387 STRIP = $(CROSS_COMPILE)strip
388 OBJCOPY = $(CROSS_COMPILE)objcopy
389 OBJDUMP = $(CROSS_COMPILE)objdump
393 GENKSYMS = scripts/genksyms/genksyms
394 INSTALLKERNEL := installkernel
395 DEPMOD = /sbin/depmod
402 CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
403 -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
412 # Use USERINCLUDE when you must reference the UAPI directories only.
414 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
415 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
416 -I$(srctree)/include/uapi \
417 -I$(objtree)/include/generated/uapi \
418 -include $(srctree)/include/linux/kconfig.h
420 # Use LINUXINCLUDE when you must reference the include/ directory.
421 # Needed to be compatible with the O= option
423 -I$(srctree)/arch/$(SRCARCH)/include \
424 -I$(objtree)/arch/$(SRCARCH)/include/generated \
425 $(if $(KBUILD_SRC), -I$(srctree)/include) \
426 -I$(objtree)/include \
429 KBUILD_AFLAGS := -D__ASSEMBLY__ -fno-PIE
430 KBUILD_CFLAGS := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
431 -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
432 -Werror-implicit-function-declaration -Werror=implicit-int \
433 -Wno-format-security \
435 KBUILD_CPPFLAGS := -D__KERNEL__
436 KBUILD_AFLAGS_KERNEL :=
437 KBUILD_CFLAGS_KERNEL :=
438 KBUILD_AFLAGS_MODULE := -DMODULE
439 KBUILD_CFLAGS_MODULE := -DMODULE
440 KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
442 GCC_PLUGINS_CFLAGS :=
444 export ARCH SRCARCH CONFIG_SHELL HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE AS LD CC
445 export CPP AR NM STRIP OBJCOPY OBJDUMP KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS
446 export MAKE LEX YACC AWK GENKSYMS INSTALLKERNEL PERL PYTHON PYTHON2 PYTHON3 UTS_MACHINE
447 export HOSTCXX KBUILD_HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
449 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
450 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
451 export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN
452 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
453 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
454 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
455 export KBUILD_ARFLAGS
457 # When compiling out-of-tree modules, put MODVERDIR in the module
458 # tree rather than in the kernel tree. The kernel tree might
460 export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
462 # Files to ignore in find ... statements
464 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
465 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
467 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
468 --exclude CVS --exclude .pc --exclude .hg --exclude .git
470 # ===========================================================================
471 # Rules shared between *config targets and build targets
473 # Basic helpers built in scripts/basic/
474 PHONY += scripts_basic
476 $(Q)$(MAKE) $(build)=scripts/basic
477 $(Q)rm -f .tmp_quiet_recordmcount
479 # To avoid any implicit rule to kick in, define an empty command.
480 scripts/basic/%: scripts_basic ;
482 PHONY += outputmakefile
483 # outputmakefile generates a Makefile in the output directory, if using a
484 # separate output directory. This allows convenient use of make in the
487 ifneq ($(KBUILD_SRC),)
488 $(Q)ln -fsn $(srctree) source
489 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
492 ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
493 ifneq ($(CROSS_COMPILE),)
494 CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE:%-=%))
495 GCC_TOOLCHAIN_DIR := $(dir $(shell which $(LD)))
496 CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)
497 GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..)
499 ifneq ($(GCC_TOOLCHAIN),)
500 CLANG_FLAGS += --gcc-toolchain=$(GCC_TOOLCHAIN)
502 CLANG_FLAGS += -no-integrated-as
503 KBUILD_CFLAGS += $(CLANG_FLAGS)
504 KBUILD_AFLAGS += $(CLANG_FLAGS)
508 RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
509 RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
510 RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
511 RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
512 RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
513 RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
514 export RETPOLINE_CFLAGS
515 export RETPOLINE_VDSO_CFLAGS
517 # The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
518 # Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
519 # CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
520 # and from include/config/auto.conf.cmd to detect the compiler upgrade.
521 CC_VERSION_TEXT = $(shell $(CC) --version | head -n 1)
523 ifeq ($(config-targets),1)
524 # ===========================================================================
525 # *config targets only - make sure prerequisites are updated, and descend
526 # in scripts/kconfig to make the *config target
528 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
529 # KBUILD_DEFCONFIG may point out an alternative default configuration
530 # used for 'make defconfig'
531 include arch/$(SRCARCH)/Makefile
532 export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
534 config: scripts_basic outputmakefile FORCE
535 $(Q)$(MAKE) $(build)=scripts/kconfig $@
537 %config: scripts_basic outputmakefile FORCE
538 $(Q)$(MAKE) $(build)=scripts/kconfig $@
541 # ===========================================================================
542 # Build targets only - this includes vmlinux, arch specific targets, clean
543 # targets and others. In general all targets except *config targets.
545 # If building an external module we do not care about the all: rule
546 # but instead _all depend on modules
548 ifeq ($(KBUILD_EXTMOD),)
554 # Decide whether to build built-in, modular, or both.
555 # Normally, just do built-in.
560 # If we have only "make modules", don't compile built-in objects.
561 # When we're building modules with modversions, we need to consider
562 # the built-in objects during the descend as well, in order to
563 # make sure the checksums are up to date before we record them.
565 ifeq ($(MAKECMDGOALS),modules)
566 KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
569 # If we have "make <whatever> modules", compile modules
570 # in addition to whatever we do anyway.
571 # Just "make" or "make all" shall build modules as well
573 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
577 ifeq ($(MAKECMDGOALS),)
581 export KBUILD_MODULES KBUILD_BUILTIN
583 ifeq ($(KBUILD_EXTMOD),)
584 # Objects we will link into vmlinux / subdirs we need to visit
586 drivers-y := drivers/ sound/ firmware/
591 endif # KBUILD_EXTMOD
593 ifeq ($(dot-config),1)
594 include include/config/auto.conf
597 # The all: target is the default when no target is given on the
599 # This allow a user to issue only 'make' to build a kernel including modules
600 # Defaults to vmlinux, but the arch makefile usually adds further targets
603 CFLAGS_GCOV := -fprofile-arcs -ftest-coverage \
604 $(call cc-option,-fno-tree-loop-im) \
605 $(call cc-disable-warning,maybe-uninitialized,)
608 # The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
609 ifdef CONFIG_FUNCTION_TRACER
610 CC_FLAGS_FTRACE := -pg
613 # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
614 # values of the respective KBUILD_* variables
618 include arch/$(SRCARCH)/Makefile
620 ifeq ($(dot-config),1)
621 ifeq ($(may-sync-config),1)
622 # Read in dependencies to all Kconfig* files, make sure to run syncconfig if
623 # changes are detected. This should be included after arch/$(SRCARCH)/Makefile
624 # because some architectures define CROSS_COMPILE there.
625 -include include/config/auto.conf.cmd
627 # To avoid any implicit rule to kick in, define an empty command
628 $(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;
630 # The actual configuration files used during the build are stored in
631 # include/generated/ and include/config/. Update them if .config is newer than
632 # include/config/auto.conf (which mirrors .config).
633 include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
634 $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
636 # External modules and some install targets need include/generated/autoconf.h
637 # and include/config/auto.conf but do not care if they are up-to-date.
638 # Use auto.conf to trigger the test
639 PHONY += include/config/auto.conf
641 include/config/auto.conf:
642 $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
644 echo >&2 " ERROR: Kernel configuration is invalid."; \
645 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
646 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
650 endif # may-sync-config
651 endif # $(dot-config)
653 KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
654 KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
655 KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
656 KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
657 KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context)
659 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
660 KBUILD_CFLAGS += $(call cc-option,-Oz,-Os)
661 KBUILD_CFLAGS += $(call cc-disable-warning,maybe-uninitialized,)
663 ifdef CONFIG_PROFILE_ALL_BRANCHES
664 KBUILD_CFLAGS += -O2 $(call cc-disable-warning,maybe-uninitialized,)
670 KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \
671 $(call cc-disable-warning,maybe-uninitialized,))
673 # Tell gcc to never replace conditional load with a non-conditional one
674 KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
676 include scripts/Makefile.kcov
677 include scripts/Makefile.gcc-plugins
679 ifdef CONFIG_READABLE_ASM
680 # Disable optimizations that make assembler listings hard to read.
681 # reorder blocks reorders the control in the function
682 # ipa clone creates specialized cloned functions
683 # partial inlining inlines only parts of functions
684 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
685 $(call cc-option,-fno-ipa-cp-clone,) \
686 $(call cc-option,-fno-partial-inlining)
689 ifneq ($(CONFIG_FRAME_WARN),0)
690 KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
693 stackp-flags-$(CONFIG_CC_HAS_STACKPROTECTOR_NONE) := -fno-stack-protector
694 stackp-flags-$(CONFIG_STACKPROTECTOR) := -fstack-protector
695 stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong
697 KBUILD_CFLAGS += $(stackp-flags-y)
699 ifdef CONFIG_CC_IS_CLANG
700 KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
701 KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
702 KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
703 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
704 # Quiet clang warning: comparison of unsigned expression < 0 is always false
705 KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
706 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
707 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
708 # See modpost pattern 2
709 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
710 KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
713 # These warnings generated too much noise in a regular build.
714 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
715 KBUILD_CFLAGS += -Wno-unused-but-set-variable
718 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
719 ifdef CONFIG_FRAME_POINTER
720 KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
722 # Some targets (ARM with Thumb2, for example), can't be built with frame
723 # pointers. For those, we don't have FUNCTION_TRACER automatically
724 # select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
725 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
726 # -fomit-frame-pointer with FUNCTION_TRACER.
727 ifndef CONFIG_FUNCTION_TRACER
728 KBUILD_CFLAGS += -fomit-frame-pointer
732 KBUILD_CFLAGS += $(call cc-option, -fno-var-tracking-assignments)
734 ifdef CONFIG_DEBUG_INFO
735 ifdef CONFIG_DEBUG_INFO_SPLIT
736 KBUILD_CFLAGS += $(call cc-option, -gsplit-dwarf, -g)
740 KBUILD_AFLAGS += -Wa,-gdwarf-2
742 ifdef CONFIG_DEBUG_INFO_DWARF4
743 KBUILD_CFLAGS += $(call cc-option, -gdwarf-4,)
746 ifdef CONFIG_DEBUG_INFO_REDUCED
747 KBUILD_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
748 $(call cc-option,-fno-var-tracking)
751 ifdef CONFIG_FUNCTION_TRACER
752 ifdef CONFIG_FTRACE_MCOUNT_RECORD
753 # gcc 5 supports generating the mcount tables directly
754 ifeq ($(call cc-option-yn,-mrecord-mcount),y)
755 CC_FLAGS_FTRACE += -mrecord-mcount
756 export CC_USING_RECORD_MCOUNT := 1
758 ifdef CONFIG_HAVE_NOP_MCOUNT
759 ifeq ($(call cc-option-yn, -mnop-mcount),y)
760 CC_FLAGS_FTRACE += -mnop-mcount
761 CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
765 ifdef CONFIG_HAVE_FENTRY
766 ifeq ($(call cc-option-yn, -mfentry),y)
767 CC_FLAGS_FTRACE += -mfentry
768 CC_FLAGS_USING += -DCC_USING_FENTRY
771 export CC_FLAGS_FTRACE
772 KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
773 KBUILD_AFLAGS += $(CC_FLAGS_USING)
774 ifdef CONFIG_DYNAMIC_FTRACE
775 ifdef CONFIG_HAVE_C_RECORDMCOUNT
776 BUILD_C_RECORDMCOUNT := y
777 export BUILD_C_RECORDMCOUNT
782 # We trigger additional mismatches with less inlining
783 ifdef CONFIG_DEBUG_SECTION_MISMATCH
784 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
787 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
788 KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
789 LDFLAGS_vmlinux += --gc-sections
792 # arch Makefile may override CC so keep this after arch Makefile is included
793 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
795 # warn about C99 declaration after statement
796 KBUILD_CFLAGS += -Wdeclaration-after-statement
798 # Variable Length Arrays (VLAs) should not be used anywhere in the kernel
799 KBUILD_CFLAGS += $(call cc-option,-Wvla)
801 # disable pointer signed / unsigned warnings in gcc 4.0
802 KBUILD_CFLAGS += -Wno-pointer-sign
804 # disable stringop warnings in gcc 8+
805 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
807 # disable invalid "can't wrap" optimizations for signed / pointers
808 KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
810 # clang sets -fmerge-all-constants by default as optimization, but this
811 # is non-conforming behavior for C and in fact breaks the kernel, so we
812 # need to disable it here generally.
813 KBUILD_CFLAGS += $(call cc-option,-fno-merge-all-constants)
815 # for gcc -fno-merge-all-constants disables everything, but it is fine
816 # to have actual conforming behavior enabled.
817 KBUILD_CFLAGS += $(call cc-option,-fmerge-constants)
819 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
820 KBUILD_CFLAGS += $(call cc-option,-fno-stack-check,)
822 # conserve stack if available
823 KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
825 # Prohibit date/time macros, which would make the build non-deterministic
826 KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
828 # enforce correct pointer usage
829 KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
831 # Require designated initializers for all marked structures
832 KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
834 # change __FILE__ to the relative path from the srctree
835 KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
837 # use the deterministic mode of AR if available
838 KBUILD_ARFLAGS := $(call ar-option,D)
840 include scripts/Makefile.kasan
841 include scripts/Makefile.extrawarn
842 include scripts/Makefile.ubsan
844 # Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
846 KBUILD_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS)
847 KBUILD_AFLAGS += $(ARCH_AFLAGS) $(KAFLAGS)
848 KBUILD_CFLAGS += $(ARCH_CFLAGS) $(KCFLAGS)
850 # Use --build-id when available.
851 LDFLAGS_BUILD_ID := $(call ld-option, --build-id)
852 KBUILD_LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
853 LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
855 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
856 LDFLAGS_vmlinux += $(call ld-option, -X,)
859 # insure the checker run with the right endianness
860 CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
862 # the checker needs the correct machine size
863 CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
865 # Default kernel image to build when no specific target is given.
866 # KBUILD_IMAGE may be overruled on the command line or
867 # set in the environment
868 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
870 export KBUILD_IMAGE ?= vmlinux
873 # INSTALL_PATH specifies where to place the updated kernel and system map
874 # images. Default is /boot, but you can set it to other values
875 export INSTALL_PATH ?= /boot
878 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
879 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
880 # an argument if needed. Otherwise it defaults to the kernel install path
882 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
885 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
886 # relocations required by build roots. This is not defined in the
887 # makefile but the argument can be passed to make if needed.
890 MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
894 # INSTALL_MOD_STRIP, if defined, will cause modules to be
895 # stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
896 # the default option --strip-debug will be used. Otherwise,
897 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
899 ifdef INSTALL_MOD_STRIP
900 ifeq ($(INSTALL_MOD_STRIP),1)
901 mod_strip_cmd = $(STRIP) --strip-debug
903 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
904 endif # INSTALL_MOD_STRIP=1
907 endif # INSTALL_MOD_STRIP
910 # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
911 # after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
912 # or CONFIG_MODULE_COMPRESS_XZ.
914 mod_compress_cmd = true
915 ifdef CONFIG_MODULE_COMPRESS
916 ifdef CONFIG_MODULE_COMPRESS_GZIP
917 mod_compress_cmd = gzip -n -f
918 endif # CONFIG_MODULE_COMPRESS_GZIP
919 ifdef CONFIG_MODULE_COMPRESS_XZ
920 mod_compress_cmd = xz -f
921 endif # CONFIG_MODULE_COMPRESS_XZ
922 endif # CONFIG_MODULE_COMPRESS
923 export mod_compress_cmd
925 # Select initial ramdisk compression format, default is gzip(1).
926 # This shall be used by the dracut(8) tool while creating an initramfs image.
928 INITRD_COMPRESS-y := gzip
929 INITRD_COMPRESS-$(CONFIG_RD_BZIP2) := bzip2
930 INITRD_COMPRESS-$(CONFIG_RD_LZMA) := lzma
931 INITRD_COMPRESS-$(CONFIG_RD_XZ) := xz
932 INITRD_COMPRESS-$(CONFIG_RD_LZO) := lzo
933 INITRD_COMPRESS-$(CONFIG_RD_LZ4) := lz4
934 # do not export INITRD_COMPRESS, since we didn't actually
935 # choose a sane default compression above.
936 # export INITRD_COMPRESS := $(INITRD_COMPRESS-y)
938 ifdef CONFIG_MODULE_SIG_ALL
939 $(eval $(call config_filename,MODULE_SIG_KEY))
941 mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
947 ifdef CONFIG_STACK_VALIDATION
948 has_libelf := $(call try-run,\
949 echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0)
950 ifeq ($(has_libelf),1)
951 objtool_target := tools/objtool FORCE
953 SKIP_STACK_VALIDATION := 1
954 export SKIP_STACK_VALIDATION
960 ifeq ($(KBUILD_EXTMOD),)
961 core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
963 vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
964 $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
965 $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
967 vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
968 $(init-) $(core-) $(drivers-) $(net-) $(libs-) $(virt-))))
970 init-y := $(patsubst %/, %/built-in.a, $(init-y))
971 core-y := $(patsubst %/, %/built-in.a, $(core-y))
972 drivers-y := $(patsubst %/, %/built-in.a, $(drivers-y))
973 net-y := $(patsubst %/, %/built-in.a, $(net-y))
974 libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
975 libs-y2 := $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y)))
976 virt-y := $(patsubst %/, %/built-in.a, $(virt-y))
978 # Externally visible symbols (used by link-vmlinux.sh)
979 export KBUILD_VMLINUX_INIT := $(head-y) $(init-y)
980 export KBUILD_VMLINUX_MAIN := $(core-y) $(libs-y2) $(drivers-y) $(net-y) $(virt-y)
981 export KBUILD_VMLINUX_LIBS := $(libs-y1)
982 export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
983 export LDFLAGS_vmlinux
984 # used by scripts/package/Makefile
985 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools)
987 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_INIT) $(KBUILD_VMLINUX_MAIN) $(KBUILD_VMLINUX_LIBS)
989 # Recurse until adjust_autoksyms.sh is satisfied
990 PHONY += autoksyms_recursive
991 autoksyms_recursive: $(vmlinux-deps)
992 ifdef CONFIG_TRIM_UNUSED_KSYMS
993 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
994 "$(MAKE) -f $(srctree)/Makefile vmlinux"
997 # For the kernel to actually contain only the needed exported symbols,
998 # we have to build modules as well to determine what those symbols are.
999 # (this can be evaluated only once include/config/auto.conf has been included)
1000 ifdef CONFIG_TRIM_UNUSED_KSYMS
1004 autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1007 $(Q)mkdir -p $(dir $@)
1010 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1012 # Final link of vmlinux with optional arch pass after final link
1013 cmd_link-vmlinux = \
1014 $(CONFIG_SHELL) $< $(LD) $(KBUILD_LDFLAGS) $(LDFLAGS_vmlinux) ; \
1015 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1017 vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1018 ifdef CONFIG_GDB_SCRIPTS
1019 $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1021 +$(call if_changed,link-vmlinux)
1025 # Build samples along the rest of the kernel. This needs headers_install.
1026 ifdef CONFIG_SAMPLES
1027 vmlinux-dirs += samples
1028 samples: headers_install
1031 # The actual objects are generated when descending,
1032 # make sure no implicit rule kicks in
1033 $(sort $(vmlinux-deps)): $(vmlinux-dirs) ;
1035 # Handle descending into subdirectories listed in $(vmlinux-dirs)
1036 # Preset locale variables to speed up the build process. Limit locale
1037 # tweaks to this spot to avoid wrong language settings when running
1038 # make menuconfig etc.
1039 # Error messages still appears in the original language
1041 PHONY += $(vmlinux-dirs)
1042 $(vmlinux-dirs): prepare
1043 $(Q)$(MAKE) $(build)=$@ need-builtin=1
1045 filechk_kernel.release = \
1046 echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1048 # Store (new) KERNELRELEASE string in include/config/kernel.release
1049 include/config/kernel.release: $(srctree)/Makefile FORCE
1050 $(call filechk,kernel.release)
1052 # Additional helpers built in scripts/
1053 # Carefully list dependencies so we do not try to build scripts twice
1056 scripts: scripts_basic scripts_dtc
1057 $(Q)$(MAKE) $(build)=$(@)
1059 # Things we need to do before we recursively start building the kernel
1060 # or the modules are listed in "prepare".
1061 # A multi level approach is used. prepareN is processed before prepareN-1.
1062 # archprepare is used in arch Makefiles and when processed asm symlink,
1063 # version.h and scripts_basic is processed / created.
1065 PHONY += prepare archprepare prepare1 prepare2 prepare3
1067 # prepare3 is used to check if we are building in a separate output directory,
1069 # 1) Check that make has not been executed in the kernel src $(srctree)
1070 prepare3: include/config/kernel.release
1071 ifneq ($(KBUILD_SRC),)
1072 @$(kecho) ' Using $(srctree) as source for kernel'
1073 $(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
1074 echo >&2 " $(srctree) is not clean, please run 'make mrproper'"; \
1075 echo >&2 " in the '$(srctree)' directory.";\
1080 # prepare2 creates a makefile if using a separate output directory.
1081 # From this point forward, .config has been reprocessed, so any rules
1082 # that need to depend on updated CONFIG_* values can be checked here.
1083 prepare2: prepare3 outputmakefile asm-generic
1085 prepare1: prepare2 $(version_h) $(autoksyms_h) 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
1104 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm
1106 PHONY += prepare-objtool
1107 prepare-objtool: $(objtool_target)
1108 ifeq ($(SKIP_STACK_VALIDATION),1)
1109 ifdef CONFIG_UNWINDER_ORC
1110 @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1113 @echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1117 # Generate some files
1118 # ---------------------------------------------------------------------------
1120 # KERNELRELEASE can change from a few different places, meaning version.h
1121 # needs to be updated, so this check is forced on all builds
1124 define filechk_utsrelease.h
1125 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1126 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1129 echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1132 define filechk_version.h
1133 echo \#define LINUX_VERSION_CODE $(shell \
1134 expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
1135 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))'
1139 $(call filechk,version.h)
1140 $(Q)rm -f $(old_version_h)
1142 include/generated/utsrelease.h: include/config/kernel.release FORCE
1143 $(call filechk,utsrelease.h)
1147 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1148 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1150 # ---------------------------------------------------------------------------
1153 #Default location for installed headers
1154 export INSTALL_HDR_PATH = $(objtree)/usr
1156 # If we do an all arch process set dst to include/arch-$(SRCARCH)
1157 hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(SRCARCH), dst=include)
1159 PHONY += archheaders archscripts
1162 __headers: $(version_h) scripts_basic uapi-asm-generic archheaders archscripts
1163 $(Q)$(MAKE) $(build)=scripts build_unifdef
1165 PHONY += headers_install_all
1166 headers_install_all:
1167 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh install
1169 PHONY += headers_install
1170 headers_install: __headers
1171 $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1172 $(error Headers not exportable for the $(SRCARCH) architecture))
1173 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include
1174 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst)
1176 PHONY += headers_check_all
1177 headers_check_all: headers_install_all
1178 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh check
1180 PHONY += headers_check
1181 headers_check: headers_install
1182 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include HDRCHECK=1
1183 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst) HDRCHECK=1
1185 ifdef CONFIG_HEADERS_CHECK
1189 # ---------------------------------------------------------------------------
1194 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1196 PHONY += kselftest-clean
1198 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests clean
1200 PHONY += kselftest-merge
1202 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1203 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \
1204 -m $(objtree)/.config \
1205 $(srctree)/tools/testing/selftests/*/config
1206 +$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1208 # ---------------------------------------------------------------------------
1211 ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1212 dtstree := arch/$(SRCARCH)/boot/dts
1217 %.dtb: prepare3 scripts_dtc
1218 $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1220 PHONY += dtbs dtbs_install dt_binding_check
1221 dtbs dtbs_check: prepare3 scripts_dtc
1222 $(Q)$(MAKE) $(build)=$(dtstree)
1224 dtbs_check: export CHECK_DTBS=1
1225 dtbs_check: dt_binding_check
1228 $(Q)$(MAKE) $(dtbinst)=$(dtstree)
1230 ifdef CONFIG_OF_EARLY_FLATTREE
1236 PHONY += scripts_dtc
1237 scripts_dtc: scripts_basic
1238 $(Q)$(MAKE) $(build)=scripts/dtc
1240 dt_binding_check: scripts_dtc
1241 $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1243 # ---------------------------------------------------------------------------
1246 ifdef CONFIG_MODULES
1248 # By default, build modules as well
1254 # A module can be listed more than once in obj-m resulting in
1255 # duplicate lines in modules.order files. Those are removed
1256 # using awk while concatenating to the final file.
1259 modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
1260 $(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
1261 @$(kecho) ' Building modules, stage 2.';
1262 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1264 modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
1265 $(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
1267 %/modules.builtin: include/config/auto.conf include/config/tristate.conf
1268 $(Q)$(MAKE) $(modbuiltin)=$*
1271 # Target to prepare building external modules
1272 PHONY += modules_prepare
1273 modules_prepare: prepare
1275 # Target to install modules
1276 PHONY += modules_install
1277 modules_install: _modinst_ _modinst_post
1281 @rm -rf $(MODLIB)/kernel
1282 @rm -f $(MODLIB)/source
1283 @mkdir -p $(MODLIB)/kernel
1284 @ln -s $(abspath $(srctree)) $(MODLIB)/source
1285 @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
1286 rm -f $(MODLIB)/build ; \
1287 ln -s $(CURDIR) $(MODLIB)/build ; \
1289 @cp -f $(objtree)/modules.order $(MODLIB)/
1290 @cp -f $(objtree)/modules.builtin $(MODLIB)/
1291 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1293 # This depmod is only for convenience to give the initial
1294 # boot a modules.dep even before / is mounted read-write. However the
1295 # boot script depmod is the master version.
1296 PHONY += _modinst_post
1297 _modinst_post: _modinst_
1300 ifeq ($(CONFIG_MODULE_SIG), y)
1301 PHONY += modules_sign
1303 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1306 else # CONFIG_MODULES
1308 # Modules not configured
1309 # ---------------------------------------------------------------------------
1311 PHONY += modules modules_install
1312 modules modules_install:
1314 @echo >&2 "The present kernel configuration has modules disabled."
1315 @echo >&2 "Type 'make config' and enable loadable module support."
1316 @echo >&2 "Then build a kernel with module support enabled."
1320 endif # CONFIG_MODULES
1323 # Cleaning is done on three levels.
1324 # make clean Delete most generated files
1325 # Leave enough to build external modules
1326 # make mrproper Delete the current configuration, and all generated files
1327 # make distclean Remove editor backup files, patch leftover files and the like
1329 # Directories & files removed with 'make clean'
1330 CLEAN_DIRS += $(MODVERDIR) include/ksym
1332 # Directories & files removed with 'make mrproper'
1333 MRPROPER_DIRS += include/config usr/include include/generated \
1334 arch/*/include/generated .tmp_objdiff
1335 MRPROPER_FILES += .config .config.old .version \
1336 Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
1337 signing_key.pem signing_key.priv signing_key.x509 \
1338 x509.genkey extra_certificates signing_key.x509.keyid \
1339 signing_key.x509.signer vmlinux-gdb.py
1341 # clean - Delete most, but leave enough to build external modules
1343 clean: rm-dirs := $(CLEAN_DIRS)
1344 clean: rm-files := $(CLEAN_FILES)
1345 clean-dirs := $(addprefix _clean_, . $(vmlinux-alldirs) Documentation samples)
1347 PHONY += $(clean-dirs) clean archclean vmlinuxclean
1349 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1352 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1353 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1355 clean: archclean vmlinuxclean
1357 # mrproper - Delete all generated files, including .config
1359 mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS))
1360 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1361 mrproper-dirs := $(addprefix _mrproper_,scripts)
1363 PHONY += $(mrproper-dirs) mrproper
1365 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1367 mrproper: clean $(mrproper-dirs)
1376 @find $(srctree) $(RCS_FIND_IGNORE) \
1377 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1378 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1379 -o -name 'core' \) \
1380 -type f -print | xargs rm -f
1383 # Packaging of the kernel to various formats
1384 # ---------------------------------------------------------------------------
1385 package-dir := scripts/package
1388 $(Q)$(MAKE) $(build)=$(package-dir) $@
1389 %pkg: include/config/kernel.release FORCE
1390 $(Q)$(MAKE) $(build)=$(package-dir) $@
1393 # Brief documentation of the typical targets used
1394 # ---------------------------------------------------------------------------
1396 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1397 boards := $(sort $(notdir $(boards)))
1398 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1399 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1403 @echo 'Cleaning targets:'
1404 @echo ' clean - Remove most generated files but keep the config and'
1405 @echo ' enough build support to build external modules'
1406 @echo ' mrproper - Remove all generated files + config + various backup files'
1407 @echo ' distclean - mrproper + remove editor backup and patch files'
1409 @echo 'Configuration targets:'
1410 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1412 @echo 'Other generic targets:'
1413 @echo ' all - Build all targets marked with [*]'
1414 @echo '* vmlinux - Build the bare kernel'
1415 @echo '* modules - Build all modules'
1416 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1417 @echo ' dir/ - Build all files in dir and below'
1418 @echo ' dir/file.[ois] - Build specified target only'
1419 @echo ' dir/file.ll - Build the LLVM assembly file'
1420 @echo ' (requires compiler support for LLVM assembly generation)'
1421 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1422 @echo ' (requires a recent binutils and recent build (System.map))'
1423 @echo ' dir/file.ko - Build module including final link'
1424 @echo ' modules_prepare - Set up for building external modules'
1425 @echo ' tags/TAGS - Generate tags file for editors'
1426 @echo ' cscope - Generate cscope index'
1427 @echo ' gtags - Generate GNU GLOBAL index'
1428 @echo ' kernelrelease - Output the release version string (use with make -s)'
1429 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1430 @echo ' image_name - Output the image name (use with make -s)'
1431 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1432 echo ' (default: $(INSTALL_HDR_PATH))'; \
1434 @echo 'Static analysers:'
1435 @echo ' checkstack - Generate a list of stack hogs'
1436 @echo ' namespacecheck - Name space analysis on compiled kernel'
1437 @echo ' versioncheck - Sanity check on version.h usage'
1438 @echo ' includecheck - Check for duplicate included header files'
1439 @echo ' export_report - List the usages of all exported symbols'
1440 @echo ' headers_check - Sanity check on exported headers'
1441 @echo ' headerdep - Detect inclusion cycles in headers'
1442 @echo ' coccicheck - Check with Coccinelle'
1444 @echo 'Kernel selftest:'
1445 @echo ' kselftest - Build and run kernel selftest (run as root)'
1446 @echo ' Build, install, and boot kernel before'
1447 @echo ' running kselftest on it'
1448 @echo ' kselftest-clean - Remove all generated kselftest files'
1449 @echo ' kselftest-merge - Merge all the config dependencies of kselftest to existing'
1453 echo 'Devicetree:'; \
1454 echo '* dtbs - Build device tree blobs for enabled boards'; \
1455 echo ' dtbs_install - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1458 @echo 'Userspace tools targets:'
1459 @echo ' use "make tools/help"'
1460 @echo ' or "cd tools; make help"'
1462 @echo 'Kernel packaging:'
1463 @$(MAKE) $(build)=$(package-dir) help
1465 @echo 'Documentation targets:'
1466 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1468 @echo 'Architecture specific targets ($(SRCARCH)):'
1469 @$(if $(archhelp),$(archhelp),\
1470 echo ' No architecture specific help defined for $(SRCARCH)')
1473 $(foreach b, $(boards), \
1474 printf " %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1476 @$(if $(board-dirs), \
1477 $(foreach b, $(board-dirs), \
1478 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1479 printf " %-16s - Show all of the above\\n" help-boards; \
1482 @echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1483 @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
1484 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1485 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK (sparse by default)'
1486 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1487 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1488 @echo ' make W=n [targets] Enable extra gcc checks, n=1,2,3 where'
1489 @echo ' 1: warnings which may be relevant and do not occur too often'
1490 @echo ' 2: warnings which occur quite often but may still be relevant'
1491 @echo ' 3: more obscure warnings, can most likely be ignored'
1492 @echo ' Multiple levels can be combined with W=12 or W=123'
1494 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1495 @echo 'For further info see the ./README file'
1498 help-board-dirs := $(addprefix help-,$(board-dirs))
1500 help-boards: $(help-board-dirs)
1502 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1504 $(help-board-dirs): help-%:
1505 @echo 'Architecture specific targets ($(SRCARCH) $*):'
1506 @$(if $(boards-per-dir), \
1507 $(foreach b, $(boards-per-dir), \
1508 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1512 # Documentation targets
1513 # ---------------------------------------------------------------------------
1514 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1515 linkcheckdocs dochelp refcheckdocs
1516 PHONY += $(DOC_TARGETS)
1517 $(DOC_TARGETS): scripts_basic FORCE
1518 $(Q)$(MAKE) $(build)=Documentation $@
1520 else # KBUILD_EXTMOD
1523 # External module support.
1524 # When building external modules the kernel used as basis is considered
1525 # read-only, and no consistency checks are made and the make
1526 # system is not used on the basis kernel. If updates are required
1527 # in the basis kernel ordinary make commands (without M=...) must
1530 # The following are the only valid targets when building external
1532 # make M=dir clean Delete all automatically generated files
1533 # make M=dir modules Make all modules in specified dir
1534 # make M=dir Same as 'make M=dir modules'
1535 # make M=dir modules_install
1536 # Install the modules built in the module directory
1537 # Assumes install directory is already created
1539 # We are always building modules
1542 PHONY += $(objtree)/Module.symvers
1543 $(objtree)/Module.symvers:
1544 @test -e $(objtree)/Module.symvers || ( \
1546 echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1547 echo " is missing; modules will have no dependencies and modversions."; \
1550 module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
1551 PHONY += $(module-dirs) modules
1552 $(module-dirs): prepare $(objtree)/Module.symvers
1553 $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
1555 modules: $(module-dirs)
1556 @$(kecho) ' Building modules, stage 2.';
1557 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1559 PHONY += modules_install
1560 modules_install: _emodinst_ _emodinst_post
1562 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1565 $(Q)mkdir -p $(MODLIB)/$(install-dir)
1566 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1568 PHONY += _emodinst_post
1569 _emodinst_post: _emodinst_
1572 clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))
1574 PHONY += $(clean-dirs) clean
1576 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1578 clean: rm-dirs := $(MODVERDIR)
1579 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1583 @echo ' Building external modules.'
1584 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1586 @echo ' modules - default target, build the module(s)'
1587 @echo ' modules_install - install the module'
1588 @echo ' clean - remove generated files in module directory only'
1594 endif # KBUILD_EXTMOD
1596 clean: $(clean-dirs)
1599 @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1600 \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1602 -o -name '*.dtb' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1603 -o -name '*.dwo' -o -name '*.lst' \
1605 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1606 -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1607 -o -name '*.asn1.[ch]' \
1608 -o -name '*.symtypes' -o -name 'modules.order' \
1609 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1610 -o -name '*.c.[012]*.*' \
1612 -o -name '*.gcno' \) -type f -print | xargs rm -f
1614 # Generate tags for editors
1615 # ---------------------------------------------------------------------------
1616 quiet_cmd_tags = GEN $@
1617 cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
1619 tags TAGS cscope gtags: FORCE
1622 # Scripts to check various things for consistency
1623 # ---------------------------------------------------------------------------
1625 PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1628 find $(srctree)/* $(RCS_FIND_IGNORE) \
1629 -name '*.[hcS]' -type f -print | sort \
1630 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1633 find $(srctree)/* $(RCS_FIND_IGNORE) \
1634 -name '*.[hcS]' -type f -print | sort \
1635 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1638 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1641 $(PERL) $(srctree)/scripts/namespace.pl
1644 $(PERL) $(srctree)/scripts/export_report.pl
1646 PHONY += checkstack kernelrelease kernelversion image_name
1648 # UML needs a little special treatment here. It wants to use the host
1649 # toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
1650 # else wants $(ARCH), including people doing cross-builds, which means
1651 # that $(SUBARCH) doesn't work here.
1653 CHECKSTACK_ARCH := $(SUBARCH)
1655 CHECKSTACK_ARCH := $(ARCH)
1658 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1659 $(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1662 @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1665 @echo $(KERNELVERSION)
1668 @echo $(KBUILD_IMAGE)
1670 # Clear a bunch of variables before executing the submake
1672 $(Q)mkdir -p $(objtree)/tools
1673 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/
1676 $(Q)mkdir -p $(objtree)/tools
1677 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/ $*
1680 # ---------------------------------------------------------------------------
1681 # Single targets are compatible with:
1682 # - build with mixed source and output
1683 # - build with separate output dir 'make O=...'
1684 # - external modules
1686 # target-dir => where to store outputfile
1687 # build-dir => directory in kernel source tree to use
1689 ifeq ($(KBUILD_EXTMOD),)
1690 build-dir = $(patsubst %/,%,$(dir $@))
1691 target-dir = $(dir $@)
1693 zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
1694 build-dir = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
1695 target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@))
1698 %.s: %.c prepare FORCE
1699 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1700 %.i: %.c prepare FORCE
1701 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1702 %.o: %.c prepare FORCE
1703 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1704 %.lst: %.c prepare FORCE
1705 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1706 %.s: %.S prepare FORCE
1707 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1708 %.o: %.S prepare FORCE
1709 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1710 %.symtypes: %.c prepare FORCE
1711 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1712 %.ll: %.c prepare FORCE
1713 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1717 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1718 $(build)=$(build-dir)
1719 # Make sure the latest headers are built for Documentation
1720 Documentation/ samples/: headers_install
1722 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1723 $(build)=$(build-dir)
1725 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1726 $(build)=$(build-dir) $(@:.ko=.o)
1727 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1729 # FIXME Should go into a make.lib or something
1730 # ===========================================================================
1732 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs)))
1733 cmd_rmdirs = rm -rf $(rm-dirs)
1735 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
1736 cmd_rmfiles = rm -f $(rm-files)
1738 # Run depmod only if we have System.map and depmod is executable
1739 quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
1740 cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1743 # Create temporary dir for module support files
1744 # clean it up only when building all modules
1745 cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
1746 $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
1748 # read saved command lines for existing targets
1749 existing-targets := $(wildcard $(sort $(targets)))
1751 cmd_files := $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1752 $(cmd_files): ; # Do not try to update included dependency files
1753 -include $(cmd_files)
1755 endif # ifeq ($(config-targets),1)
1756 endif # ifeq ($(mixed-targets),1)
1757 endif # skip-makefile
1762 # Declare the contents of the PHONY variable as phony. We keep that
1763 # information in a variable so we can use it in if_changed and friends.