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 # o Do not use make's built-in rules and variables
19 # (this increases performance and avoids hard-to-debug behaviour);
20 # o Look for make include files relative to root of kernel src
21 MAKEFLAGS += -rR --include-dir=$(CURDIR)
23 # Avoid funny character set dependencies
27 export LC_COLLATE LC_NUMERIC
29 # Avoid interference with shell env settings
32 # We are using a recursive build, so we need to do a little thinking
33 # to get the ordering right.
35 # Most importantly: sub-Makefiles should only ever modify files in
36 # their own directory. If in some directory we have a dependency on
37 # a file in another dir (which doesn't happen often, but it's often
38 # unavoidable when linking the built-in.o targets which finally
39 # turn into vmlinux), we will call a sub make in that other dir, and
40 # after that we are sure that everything which is in that other dir
43 # The only cases where we need to modify files which have global
44 # effects are thus separated out and done before the recursive
45 # descending is started. They are now explicitly listed as the
49 # ---------------------------------------------------------------------------
51 # Normally, we echo the whole command before executing it. By making
52 # that echo $($(quiet)$(cmd)), we now have the possibility to set
53 # $(quiet) to choose other forms of output instead, e.g.
55 # quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
56 # cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
58 # If $(quiet) is empty, the whole command will be printed.
59 # If it is set to "quiet_", only the short version will be printed.
60 # If it is set to "silent_", nothing will be printed at all, since
61 # the variable $(silent_cmd_cc_o_c) doesn't exist.
63 # A simple variant is to prefix commands with $(Q) - that's useful
64 # for commands that shall be hidden in non-verbose mode.
68 # If KBUILD_VERBOSE equals 0 then the above command will be hidden.
69 # If KBUILD_VERBOSE equals 1 then the above command is displayed.
71 # To put more focus on warnings, be less verbose as default
72 # Use 'make V=1' to see the full commands
74 ifeq ("$(origin V)", "command line")
81 ifeq ($(KBUILD_VERBOSE),1)
89 # If the user is running make -s (silent mode), suppress echoing of
92 ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
97 export quiet Q KBUILD_VERBOSE
99 # kbuild supports saving output files in a separate directory.
100 # To locate output files in a separate directory two syntaxes are supported.
101 # In both cases the working directory must be the root of the kernel src.
103 # Use "make O=dir/to/store/output/files/"
105 # 2) Set KBUILD_OUTPUT
106 # Set the environment variable KBUILD_OUTPUT to point to the directory
107 # where the output files shall be placed.
108 # export KBUILD_OUTPUT=dir/to/store/output/files/
111 # The O= assignment takes precedence over the KBUILD_OUTPUT environment
114 # KBUILD_SRC is not intended to be used by the regular user (for now),
115 # it is set on invocation of make with KBUILD_OUTPUT or O= specified.
116 ifeq ($(KBUILD_SRC),)
118 # OK, Make called in directory where kernel src resides
119 # Do we want to locate output files in a separate directory?
120 ifeq ("$(origin O)", "command line")
121 KBUILD_OUTPUT := $(O)
124 # Cancel implicit rules on top Makefile
125 $(CURDIR)/Makefile Makefile: ;
127 ifneq ($(words $(subst :, ,$(CURDIR))), 1)
128 $(error main directory cannot contain spaces nor colons)
131 ifneq ($(KBUILD_OUTPUT),)
132 # check that the output directory actually exists
133 saved-output := $(KBUILD_OUTPUT)
134 KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
136 $(if $(KBUILD_OUTPUT),, \
137 $(error failed to create output directory "$(saved-output)"))
139 PHONY += $(MAKECMDGOALS) sub-make
141 $(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
144 # Invoke a second make in the output directory, passing relevant variables
146 $(Q)$(MAKE) -C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR) \
147 -f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS))
149 # Leave processing to above invocation of make
151 endif # ifneq ($(KBUILD_OUTPUT),)
152 endif # ifeq ($(KBUILD_SRC),)
154 # We process the rest of the Makefile if this is the final invocation of make
155 ifeq ($(skip-makefile),)
157 # Do not print "Entering directory ...",
158 # but we want to display it when entering to the output directory
159 # so that IDEs/editors are able to understand relative filenames.
160 MAKEFLAGS += --no-print-directory
162 # Call a source code checker (by default, "sparse") as part of the
165 # Use 'make C=1' to enable checking of only re-compiled files.
166 # Use 'make C=2' to enable checking of *all* source files, regardless
167 # of whether they are re-compiled or not.
169 # See the file "Documentation/dev-tools/sparse.rst" for more details,
170 # including where to get the "sparse" utility.
172 ifeq ("$(origin C)", "command line")
173 KBUILD_CHECKSRC = $(C)
175 ifndef KBUILD_CHECKSRC
179 # Use make M=dir to specify directory of external module to build
180 # Old syntax make ... SUBDIRS=$PWD is still supported
181 # Setting the environment variable KBUILD_EXTMOD take precedence
183 KBUILD_EXTMOD ?= $(SUBDIRS)
186 ifeq ("$(origin M)", "command line")
187 KBUILD_EXTMOD := $(M)
190 ifeq ($(KBUILD_SRC),)
191 # building in the source tree
194 ifeq ($(KBUILD_SRC)/,$(dir $(CURDIR)))
195 # building in a subdirectory of the source tree
198 srctree := $(KBUILD_SRC)
202 export KBUILD_CHECKSRC KBUILD_EXTMOD KBUILD_SRC
208 VPATH := $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))
210 export srctree objtree VPATH
212 # To make sure we do not include .config for any of the *config targets
213 # catch them early, and hand them over to scripts/kconfig/Makefile
214 # It is allowed to specify more targets when calling make, including
215 # mixing *config targets and build targets.
216 # For example 'make oldconfig all'.
217 # Detect when mixed targets is specified, and make a second invocation
218 # of make so .config is not included in this case either (for *config).
220 version_h := include/generated/uapi/linux/version.h
221 old_version_h := include/linux/version.h
223 no-dot-config-targets := clean mrproper distclean \
224 cscope gtags TAGS tags help% %docs check% coccicheck \
225 $(version_h) headers_% archheaders archscripts \
226 kernelversion %src-pkg
232 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
233 ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
238 ifeq ($(KBUILD_EXTMOD),)
239 ifneq ($(filter config %config,$(MAKECMDGOALS)),)
241 ifneq ($(words $(MAKECMDGOALS)),1)
246 # install and modules_install need also be processed one by one
247 ifneq ($(filter install,$(MAKECMDGOALS)),)
248 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
253 ifeq ($(mixed-targets),1)
254 # ===========================================================================
255 # We're called with mixed targets (*config and build targets).
256 # Handle them one by one.
258 PHONY += $(MAKECMDGOALS) __build_one_by_one
260 $(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
265 for i in $(MAKECMDGOALS); do \
266 $(MAKE) -f $(srctree)/Makefile $$i; \
271 # We need some generic definitions (do not try to remake the file).
272 scripts/Kbuild.include: ;
273 include scripts/Kbuild.include
275 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
276 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
277 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
278 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
280 # SUBARCH tells the usermode build what the underlying arch is. That is set
281 # first, and if a usermode build is happening, the "ARCH=um" on the command
282 # line overrides the setting of ARCH below. If a native build is happening,
283 # then ARCH is assigned, getting whatever value it gets normally, and
284 # SUBARCH is subsequently ignored.
286 SUBARCH := $(shell uname -m | sed -e s/i.86/x86/ -e s/x86_64/x86/ \
287 -e s/sun4u/sparc64/ \
288 -e s/arm.*/arm/ -e s/sa110/arm/ \
289 -e s/s390x/s390/ -e s/parisc64/parisc/ \
290 -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
291 -e s/sh[234].*/sh/ -e s/aarch64.*/arm64/ \
294 # Cross compiling and selecting different set of gcc/bin-utils
295 # ---------------------------------------------------------------------------
297 # When performing cross compilation for other architectures ARCH shall be set
298 # to the target architecture. (See arch/* for the possibilities).
299 # ARCH can be set during invocation of make:
301 # Another way is to have ARCH set in the environment.
302 # The default ARCH is the host where make is executed.
304 # CROSS_COMPILE specify the prefix used for all executables used
305 # during compilation. Only gcc and related bin-utils executables
306 # are prefixed with $(CROSS_COMPILE).
307 # CROSS_COMPILE can be set on the command line
308 # make CROSS_COMPILE=ia64-linux-
309 # Alternatively CROSS_COMPILE can be set in the environment.
310 # A third alternative is to store a setting in .config so that plain
311 # "make" in the configured kernel build directory always uses that.
312 # Default value for CROSS_COMPILE is not to prefix executables
313 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
315 CROSS_COMPILE ?= $(CONFIG_CROSS_COMPILE:"%"=%)
317 # Architecture as present in compile.h
318 UTS_MACHINE := $(ARCH)
321 # Additional ARCH settings for x86
325 ifeq ($(ARCH),x86_64)
329 # Additional ARCH settings for sparc
330 ifeq ($(ARCH),sparc32)
333 ifeq ($(ARCH),sparc64)
337 # Additional ARCH settings for sh
342 # Additional ARCH settings for tile
343 ifeq ($(ARCH),tilepro)
346 ifeq ($(ARCH),tilegx)
350 KCONFIG_CONFIG ?= .config
351 export KCONFIG_CONFIG
353 # SHELL used by kbuild
354 CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
355 else if [ -x /bin/bash ]; then echo /bin/bash; \
356 else echo sh; fi ; fi)
358 HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS)
359 HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS)
360 HOST_LFS_LIBS := $(shell getconf LFS_LIBS)
364 HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 \
365 -fomit-frame-pointer -std=gnu89 $(HOST_LFS_CFLAGS)
366 HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS)
367 HOSTLDFLAGS := $(HOST_LFS_LDFLAGS)
368 HOST_LOADLIBES := $(HOST_LFS_LIBS)
370 # Make variables (CC, etc...)
371 AS = $(CROSS_COMPILE)as
372 LD = $(CROSS_COMPILE)ld
373 CC = $(CROSS_COMPILE)gcc
375 AR = $(CROSS_COMPILE)ar
376 NM = $(CROSS_COMPILE)nm
377 STRIP = $(CROSS_COMPILE)strip
378 OBJCOPY = $(CROSS_COMPILE)objcopy
379 OBJDUMP = $(CROSS_COMPILE)objdump
381 GENKSYMS = scripts/genksyms/genksyms
382 INSTALLKERNEL := installkernel
383 DEPMOD = /sbin/depmod
388 CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
389 -Wbitwise -Wno-return-void $(CF)
398 # Use USERINCLUDE when you must reference the UAPI directories only.
400 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
401 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
402 -I$(srctree)/include/uapi \
403 -I$(objtree)/include/generated/uapi \
404 -include $(srctree)/include/linux/kconfig.h
406 # Use LINUXINCLUDE when you must reference the include/ directory.
407 # Needed to be compatible with the O= option
409 -I$(srctree)/arch/$(SRCARCH)/include \
410 -I$(objtree)/arch/$(SRCARCH)/include/generated \
411 $(if $(KBUILD_SRC), -I$(srctree)/include) \
412 -I$(objtree)/include \
415 KBUILD_AFLAGS := -D__ASSEMBLY__
416 KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
417 -fno-strict-aliasing -fno-common -fshort-wchar \
418 -Werror-implicit-function-declaration \
419 -Wno-format-security \
421 KBUILD_CPPFLAGS := -D__KERNEL__
422 KBUILD_AFLAGS_KERNEL :=
423 KBUILD_CFLAGS_KERNEL :=
424 KBUILD_AFLAGS_MODULE := -DMODULE
425 KBUILD_CFLAGS_MODULE := -DMODULE
426 KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
427 GCC_PLUGINS_CFLAGS :=
429 export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC
430 export CPP AR NM STRIP OBJCOPY OBJDUMP HOSTLDFLAGS HOST_LOADLIBES
431 export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE
432 export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
434 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
435 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_KASAN CFLAGS_UBSAN
436 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
437 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
438 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
439 export KBUILD_ARFLAGS
441 # When compiling out-of-tree modules, put MODVERDIR in the module
442 # tree rather than in the kernel tree. The kernel tree might
444 export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
446 # Files to ignore in find ... statements
448 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
449 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
451 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
452 --exclude CVS --exclude .pc --exclude .hg --exclude .git
454 # ===========================================================================
455 # Rules shared between *config targets and build targets
457 # Basic helpers built in scripts/basic/
458 PHONY += scripts_basic
460 $(Q)$(MAKE) $(build)=scripts/basic
461 $(Q)rm -f .tmp_quiet_recordmcount
463 # To avoid any implicit rule to kick in, define an empty command.
464 scripts/basic/%: scripts_basic ;
466 PHONY += outputmakefile
467 # outputmakefile generates a Makefile in the output directory, if using a
468 # separate output directory. This allows convenient use of make in the
471 ifneq ($(KBUILD_SRC),)
472 $(Q)ln -fsn $(srctree) source
473 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile \
474 $(srctree) $(objtree) $(VERSION) $(PATCHLEVEL)
477 ifeq ($(cc-name),clang)
478 ifneq ($(CROSS_COMPILE),)
479 CLANG_TARGET := --target=$(notdir $(CROSS_COMPILE:%-=%))
480 GCC_TOOLCHAIN := $(realpath $(dir $(shell which $(LD)))/..)
482 ifneq ($(GCC_TOOLCHAIN),)
483 CLANG_GCC_TC := --gcc-toolchain=$(GCC_TOOLCHAIN)
485 KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
486 KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
487 KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
488 KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable)
489 KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
490 KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
491 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
492 # Quiet clang warning: comparison of unsigned expression < 0 is always false
493 KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
494 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
495 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
496 # See modpost pattern 2
497 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
498 KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
499 KBUILD_CFLAGS += $(call cc-option, -no-integrated-as)
500 KBUILD_AFLAGS += $(call cc-option, -no-integrated-as)
503 # These warnings generated too much noise in a regular build.
504 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
505 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
506 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
509 ifeq ($(config-targets),1)
510 # ===========================================================================
511 # *config targets only - make sure prerequisites are updated, and descend
512 # in scripts/kconfig to make the *config target
514 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
515 # KBUILD_DEFCONFIG may point out an alternative default configuration
516 # used for 'make defconfig'
517 include arch/$(SRCARCH)/Makefile
518 export KBUILD_DEFCONFIG KBUILD_KCONFIG
520 config: scripts_basic outputmakefile FORCE
521 $(Q)$(MAKE) $(build)=scripts/kconfig $@
523 %config: scripts_basic outputmakefile FORCE
524 $(Q)$(MAKE) $(build)=scripts/kconfig $@
527 # ===========================================================================
528 # Build targets only - this includes vmlinux, arch specific targets, clean
529 # targets and others. In general all targets except *config targets.
531 # If building an external module we do not care about the all: rule
532 # but instead _all depend on modules
534 ifeq ($(KBUILD_EXTMOD),)
540 # Decide whether to build built-in, modular, or both.
541 # Normally, just do built-in.
546 # If we have only "make modules", don't compile built-in objects.
547 # When we're building modules with modversions, we need to consider
548 # the built-in objects during the descend as well, in order to
549 # make sure the checksums are up to date before we record them.
551 ifeq ($(MAKECMDGOALS),modules)
552 KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
555 # If we have "make <whatever> modules", compile modules
556 # in addition to whatever we do anyway.
557 # Just "make" or "make all" shall build modules as well
559 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
563 ifeq ($(MAKECMDGOALS),)
567 export KBUILD_MODULES KBUILD_BUILTIN
569 ifeq ($(KBUILD_EXTMOD),)
570 # Additional helpers built in scripts/
571 # Carefully list dependencies so we do not try to build scripts twice
574 scripts: scripts_basic include/config/auto.conf include/config/tristate.conf \
575 asm-generic gcc-plugins
576 $(Q)$(MAKE) $(build)=$(@)
578 # Objects we will link into vmlinux / subdirs we need to visit
580 drivers-y := drivers/ sound/ firmware/
585 endif # KBUILD_EXTMOD
587 ifeq ($(dot-config),1)
589 -include include/config/auto.conf
591 ifeq ($(KBUILD_EXTMOD),)
592 # Read in dependencies to all Kconfig* files, make sure to run
593 # oldconfig if changes are detected.
594 -include include/config/auto.conf.cmd
596 # To avoid any implicit rule to kick in, define an empty command
597 $(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;
599 # If .config is newer than include/config/auto.conf, someone tinkered
600 # with it and forgot to run make oldconfig.
601 # if auto.conf.cmd is missing then we are probably in a cleaned tree so
602 # we execute the config step to be sure to catch updated Kconfig files
603 include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
604 $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig
606 # external modules needs include/generated/autoconf.h and include/config/auto.conf
607 # but do not care if they are up-to-date. Use auto.conf to trigger the test
608 PHONY += include/config/auto.conf
610 include/config/auto.conf:
611 $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
613 echo >&2 " ERROR: Kernel configuration is invalid."; \
614 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
615 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
619 endif # KBUILD_EXTMOD
622 # Dummy target needed, because used as prerequisite
623 include/config/auto.conf: ;
624 endif # $(dot-config)
626 # For the kernel to actually contain only the needed exported symbols,
627 # we have to build modules as well to determine what those symbols are.
628 # (this can be evaluated only once include/config/auto.conf has been included)
629 ifdef CONFIG_TRIM_UNUSED_KSYMS
633 # The all: target is the default when no target is given on the
635 # This allow a user to issue only 'make' to build a kernel including modules
636 # Defaults to vmlinux, but the arch makefile usually adds further targets
639 KBUILD_CFLAGS += $(call cc-option,-fno-PIE)
640 KBUILD_AFLAGS += $(call cc-option,-fno-PIE)
641 CFLAGS_GCOV := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,)
642 export CFLAGS_GCOV CFLAGS_KCOV
644 # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
645 # values of the respective KBUILD_* variables
649 include arch/$(SRCARCH)/Makefile
651 KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
652 KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
653 KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
654 KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
655 KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context)
657 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
658 KBUILD_CFLAGS += $(call cc-option,-Oz,-Os)
659 KBUILD_CFLAGS += $(call cc-disable-warning,maybe-uninitialized,)
661 ifdef CONFIG_PROFILE_ALL_BRANCHES
662 KBUILD_CFLAGS += -O2 $(call cc-disable-warning,maybe-uninitialized,)
668 KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \
669 $(call cc-disable-warning,maybe-uninitialized,))
671 # Tell gcc to never replace conditional load with a non-conditional one
672 KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
674 # check for 'asm goto'
675 ifeq ($(call shell-cached,$(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y)
676 KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
677 KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO
680 include scripts/Makefile.kcov
681 include scripts/Makefile.gcc-plugins
683 ifdef CONFIG_READABLE_ASM
684 # Disable optimizations that make assembler listings hard to read.
685 # reorder blocks reorders the control in the function
686 # ipa clone creates specialized cloned functions
687 # partial inlining inlines only parts of functions
688 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
689 $(call cc-option,-fno-ipa-cp-clone,) \
690 $(call cc-option,-fno-partial-inlining)
693 ifneq ($(CONFIG_FRAME_WARN),0)
694 KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
697 # This selects the stack protector compiler flag. Testing it is delayed
698 # until after .config has been reprocessed, in the prepare-compiler-check
700 ifdef CONFIG_CC_STACKPROTECTOR_REGULAR
701 stackp-flag := -fstack-protector
702 stackp-name := REGULAR
704 ifdef CONFIG_CC_STACKPROTECTOR_STRONG
705 stackp-flag := -fstack-protector-strong
706 stackp-name := STRONG
708 # Force off for distro compilers that enable stack protector by default.
709 stackp-flag := $(call cc-option, -fno-stack-protector)
712 # Find arch-specific stack protector compiler sanity-checking script.
713 ifdef CONFIG_CC_STACKPROTECTOR
714 stackp-path := $(srctree)/scripts/gcc-$(SRCARCH)_$(BITS)-has-stack-protector.sh
715 stackp-check := $(wildcard $(stackp-path))
717 KBUILD_CFLAGS += $(stackp-flag)
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 ifndef CC_FLAGS_FTRACE
753 CC_FLAGS_FTRACE := -pg
755 export CC_FLAGS_FTRACE
756 ifdef CONFIG_HAVE_FENTRY
757 CC_USING_FENTRY := $(call cc-option, -mfentry -DCC_USING_FENTRY)
759 KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_USING_FENTRY)
760 KBUILD_AFLAGS += $(CC_USING_FENTRY)
761 ifdef CONFIG_DYNAMIC_FTRACE
762 ifdef CONFIG_HAVE_C_RECORDMCOUNT
763 BUILD_C_RECORDMCOUNT := y
764 export BUILD_C_RECORDMCOUNT
769 # We trigger additional mismatches with less inlining
770 ifdef CONFIG_DEBUG_SECTION_MISMATCH
771 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
774 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
775 KBUILD_CFLAGS += $(call cc-option,-ffunction-sections,)
776 KBUILD_CFLAGS += $(call cc-option,-fdata-sections,)
779 # arch Makefile may override CC so keep this after arch Makefile is included
780 NOSTDINC_FLAGS += -nostdinc -isystem $(call shell-cached,$(CC) -print-file-name=include)
781 CHECKFLAGS += $(NOSTDINC_FLAGS)
783 # warn about C99 declaration after statement
784 KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
786 # disable pointer signed / unsigned warnings in gcc 4.0
787 KBUILD_CFLAGS += $(call cc-disable-warning, pointer-sign)
789 # disable invalid "can't wrap" optimizations for signed / pointers
790 KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
792 # conserve stack if available
793 KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
795 # disallow errors like 'EXPORT_GPL(foo);' with missing header
796 KBUILD_CFLAGS += $(call cc-option,-Werror=implicit-int)
798 # require functions to have arguments in prototypes, not empty 'int foo()'
799 KBUILD_CFLAGS += $(call cc-option,-Werror=strict-prototypes)
801 # Prohibit date/time macros, which would make the build non-deterministic
802 KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
804 # enforce correct pointer usage
805 KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
807 # Require designated initializers for all marked structures
808 KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
810 # use the deterministic mode of AR if available
811 KBUILD_ARFLAGS := $(call ar-option,D)
813 include scripts/Makefile.kasan
814 include scripts/Makefile.extrawarn
815 include scripts/Makefile.ubsan
817 # Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
819 KBUILD_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS)
820 KBUILD_AFLAGS += $(ARCH_AFLAGS) $(KAFLAGS)
821 KBUILD_CFLAGS += $(ARCH_CFLAGS) $(KCFLAGS)
823 # Use --build-id when available.
824 LDFLAGS_BUILD_ID := $(patsubst -Wl$(comma)%,%,\
825 $(call cc-ldoption, -Wl$(comma)--build-id,))
826 KBUILD_LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
827 LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
829 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
830 LDFLAGS_vmlinux += $(call ld-option, --gc-sections,)
833 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
834 LDFLAGS_vmlinux += $(call ld-option, -X,)
837 # Default kernel image to build when no specific target is given.
838 # KBUILD_IMAGE may be overruled on the command line or
839 # set in the environment
840 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
842 export KBUILD_IMAGE ?= vmlinux
845 # INSTALL_PATH specifies where to place the updated kernel and system map
846 # images. Default is /boot, but you can set it to other values
847 export INSTALL_PATH ?= /boot
850 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
851 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
852 # an argument if needed. Otherwise it defaults to the kernel install path
854 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
857 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
858 # relocations required by build roots. This is not defined in the
859 # makefile but the argument can be passed to make if needed.
862 MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
866 # INSTALL_MOD_STRIP, if defined, will cause modules to be
867 # stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
868 # the default option --strip-debug will be used. Otherwise,
869 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
871 ifdef INSTALL_MOD_STRIP
872 ifeq ($(INSTALL_MOD_STRIP),1)
873 mod_strip_cmd = $(STRIP) --strip-debug
875 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
876 endif # INSTALL_MOD_STRIP=1
879 endif # INSTALL_MOD_STRIP
882 # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
883 # after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
884 # or CONFIG_MODULE_COMPRESS_XZ.
886 mod_compress_cmd = true
887 ifdef CONFIG_MODULE_COMPRESS
888 ifdef CONFIG_MODULE_COMPRESS_GZIP
889 mod_compress_cmd = gzip -n -f
890 endif # CONFIG_MODULE_COMPRESS_GZIP
891 ifdef CONFIG_MODULE_COMPRESS_XZ
892 mod_compress_cmd = xz -f
893 endif # CONFIG_MODULE_COMPRESS_XZ
894 endif # CONFIG_MODULE_COMPRESS
895 export mod_compress_cmd
897 # Select initial ramdisk compression format, default is gzip(1).
898 # This shall be used by the dracut(8) tool while creating an initramfs image.
900 INITRD_COMPRESS-y := gzip
901 INITRD_COMPRESS-$(CONFIG_RD_BZIP2) := bzip2
902 INITRD_COMPRESS-$(CONFIG_RD_LZMA) := lzma
903 INITRD_COMPRESS-$(CONFIG_RD_XZ) := xz
904 INITRD_COMPRESS-$(CONFIG_RD_LZO) := lzo
905 INITRD_COMPRESS-$(CONFIG_RD_LZ4) := lz4
906 # do not export INITRD_COMPRESS, since we didn't actually
907 # choose a sane default compression above.
908 # export INITRD_COMPRESS := $(INITRD_COMPRESS-y)
910 ifdef CONFIG_MODULE_SIG_ALL
911 $(eval $(call config_filename,MODULE_SIG_KEY))
913 mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
919 ifdef CONFIG_STACK_VALIDATION
920 has_libelf := $(call try-run,\
921 echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0)
922 ifeq ($(has_libelf),1)
923 objtool_target := tools/objtool FORCE
925 ifdef CONFIG_UNWINDER_ORC
926 $(error "Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel")
928 $(warning "Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel")
930 SKIP_STACK_VALIDATION := 1
931 export SKIP_STACK_VALIDATION
936 ifeq ($(KBUILD_EXTMOD),)
937 core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
939 vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
940 $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
941 $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
943 vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
944 $(init-) $(core-) $(drivers-) $(net-) $(libs-) $(virt-))))
946 init-y := $(patsubst %/, %/built-in.o, $(init-y))
947 core-y := $(patsubst %/, %/built-in.o, $(core-y))
948 drivers-y := $(patsubst %/, %/built-in.o, $(drivers-y))
949 net-y := $(patsubst %/, %/built-in.o, $(net-y))
950 libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
951 libs-y2 := $(filter-out %.a, $(patsubst %/, %/built-in.o, $(libs-y)))
952 virt-y := $(patsubst %/, %/built-in.o, $(virt-y))
954 # Externally visible symbols (used by link-vmlinux.sh)
955 export KBUILD_VMLINUX_INIT := $(head-y) $(init-y)
956 export KBUILD_VMLINUX_MAIN := $(core-y) $(libs-y2) $(drivers-y) $(net-y) $(virt-y)
957 export KBUILD_VMLINUX_LIBS := $(libs-y1)
958 export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
959 export LDFLAGS_vmlinux
960 # used by scripts/package/Makefile
961 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools)
963 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_INIT) $(KBUILD_VMLINUX_MAIN) $(KBUILD_VMLINUX_LIBS)
965 # Include targets which we want to execute sequentially if the rest of the
966 # kernel build went well. If CONFIG_TRIM_UNUSED_KSYMS is set, this might be
967 # evaluated more than once.
968 PHONY += vmlinux_prereq
969 vmlinux_prereq: $(vmlinux-deps) FORCE
970 ifdef CONFIG_HEADERS_CHECK
971 $(Q)$(MAKE) -f $(srctree)/Makefile headers_check
973 ifdef CONFIG_GDB_SCRIPTS
974 $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
976 ifdef CONFIG_TRIM_UNUSED_KSYMS
977 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
978 "$(MAKE) -f $(srctree)/Makefile vmlinux"
981 # standalone target for easier testing
982 include/generated/autoksyms.h: FORCE
983 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh true
985 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
987 # Final link of vmlinux with optional arch pass after final link
989 $(CONFIG_SHELL) $< $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) ; \
990 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
992 vmlinux: scripts/link-vmlinux.sh vmlinux_prereq $(vmlinux-deps) FORCE
993 +$(call if_changed,link-vmlinux)
995 # Build samples along the rest of the kernel
997 vmlinux-dirs += samples
1000 # The actual objects are generated when descending,
1001 # make sure no implicit rule kicks in
1002 $(sort $(vmlinux-deps)): $(vmlinux-dirs) ;
1004 # Handle descending into subdirectories listed in $(vmlinux-dirs)
1005 # Preset locale variables to speed up the build process. Limit locale
1006 # tweaks to this spot to avoid wrong language settings when running
1007 # make menuconfig etc.
1008 # Error messages still appears in the original language
1010 PHONY += $(vmlinux-dirs)
1011 $(vmlinux-dirs): prepare scripts
1012 $(Q)$(MAKE) $(build)=$@ need-builtin=1
1014 define filechk_kernel.release
1015 echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1018 # Store (new) KERNELRELEASE string in include/config/kernel.release
1019 include/config/kernel.release: include/config/auto.conf FORCE
1020 $(call filechk,kernel.release)
1023 # Things we need to do before we recursively start building the kernel
1024 # or the modules are listed in "prepare".
1025 # A multi level approach is used. prepareN is processed before prepareN-1.
1026 # archprepare is used in arch Makefiles and when processed asm symlink,
1027 # version.h and scripts_basic is processed / created.
1029 # Listed in dependency order
1030 PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3
1032 # prepare3 is used to check if we are building in a separate output directory,
1034 # 1) Check that make has not been executed in the kernel src $(srctree)
1035 prepare3: include/config/kernel.release
1036 ifneq ($(KBUILD_SRC),)
1037 @$(kecho) ' Using $(srctree) as source for kernel'
1038 $(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
1039 echo >&2 " $(srctree) is not clean, please run 'make mrproper'"; \
1040 echo >&2 " in the '$(srctree)' directory.";\
1045 # prepare2 creates a makefile if using a separate output directory.
1046 # From this point forward, .config has been reprocessed, so any rules
1047 # that need to depend on updated CONFIG_* values can be checked here.
1048 prepare2: prepare3 prepare-compiler-check outputmakefile asm-generic
1050 prepare1: prepare2 $(version_h) include/generated/utsrelease.h \
1051 include/config/auto.conf
1054 archprepare: archheaders archscripts prepare1 scripts_basic
1056 prepare0: archprepare gcc-plugins
1057 $(Q)$(MAKE) $(build)=.
1059 # All the preparing..
1060 prepare: prepare0 prepare-objtool
1062 # Support for using generic headers in asm-generic
1063 PHONY += asm-generic uapi-asm-generic
1064 asm-generic: uapi-asm-generic
1065 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
1066 src=asm obj=arch/$(SRCARCH)/include/generated/asm
1068 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
1069 src=uapi/asm obj=arch/$(SRCARCH)/include/generated/uapi/asm
1071 PHONY += prepare-objtool
1072 prepare-objtool: $(objtool_target)
1074 # Check for CONFIG flags that require compiler support. Abort the build
1075 # after .config has been processed, but before the kernel build starts.
1077 # For security-sensitive CONFIG options, we don't want to fallback and/or
1078 # silently change which compiler flags will be used, since that leads to
1079 # producing kernels with different security feature characteristics
1080 # depending on the compiler used. (For example, "But I selected
1081 # CC_STACKPROTECTOR_STRONG! Why did it build with _REGULAR?!")
1082 PHONY += prepare-compiler-check
1083 prepare-compiler-check: FORCE
1084 # Make sure compiler supports requested stack protector flag.
1086 ifeq ($(call cc-option, $(stackp-flag)),)
1087 @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1088 $(stackp-flag) not supported by compiler >&2 && exit 1
1091 # Make sure compiler does not have buggy stack-protector support.
1093 ifneq ($(shell $(CONFIG_SHELL) $(stackp-check) $(CC) $(KBUILD_CPPFLAGS) $(biarch)),y)
1094 @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1095 $(stackp-flag) available but compiler is broken >&2 && exit 1
1100 # Generate some files
1101 # ---------------------------------------------------------------------------
1103 # KERNELRELEASE can change from a few different places, meaning version.h
1104 # needs to be updated, so this check is forced on all builds
1107 define filechk_utsrelease.h
1108 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1109 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1112 (echo \#define UTS_RELEASE \"$(KERNELRELEASE)\";)
1115 define filechk_version.h
1116 (echo \#define LINUX_VERSION_CODE $(shell \
1117 expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
1118 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))';)
1121 $(version_h): $(srctree)/Makefile FORCE
1122 $(call filechk,version.h)
1123 $(Q)rm -f $(old_version_h)
1125 include/generated/utsrelease.h: include/config/kernel.release FORCE
1126 $(call filechk,utsrelease.h)
1130 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1131 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1133 # ---------------------------------------------------------------------------
1136 #Default location for installed headers
1137 export INSTALL_HDR_PATH = $(objtree)/usr
1139 # If we do an all arch process set dst to include/arch-$(SRCARCH)
1140 hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(SRCARCH), dst=include)
1142 PHONY += archheaders
1145 PHONY += archscripts
1149 __headers: $(version_h) scripts_basic uapi-asm-generic archheaders archscripts
1150 $(Q)$(MAKE) $(build)=scripts build_unifdef
1152 PHONY += headers_install_all
1153 headers_install_all:
1154 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh install
1156 PHONY += headers_install
1157 headers_install: __headers
1158 $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1159 $(error Headers not exportable for the $(SRCARCH) architecture))
1160 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include
1161 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst)
1163 PHONY += headers_check_all
1164 headers_check_all: headers_install_all
1165 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh check
1167 PHONY += headers_check
1168 headers_check: headers_install
1169 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include HDRCHECK=1
1170 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst) HDRCHECK=1
1172 # ---------------------------------------------------------------------------
1177 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1179 PHONY += kselftest-clean
1181 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests clean
1183 PHONY += kselftest-merge
1185 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1186 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \
1187 -m $(objtree)/.config \
1188 $(srctree)/tools/testing/selftests/*/config
1189 +$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1191 # ---------------------------------------------------------------------------
1194 ifdef CONFIG_MODULES
1196 # By default, build modules as well
1202 # A module can be listed more than once in obj-m resulting in
1203 # duplicate lines in modules.order files. Those are removed
1204 # using awk while concatenating to the final file.
1207 modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
1208 $(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
1209 @$(kecho) ' Building modules, stage 2.';
1210 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1212 modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
1213 $(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
1215 %/modules.builtin: include/config/auto.conf
1216 $(Q)$(MAKE) $(modbuiltin)=$*
1219 # Target to prepare building external modules
1220 PHONY += modules_prepare
1221 modules_prepare: prepare scripts
1223 # Target to install modules
1224 PHONY += modules_install
1225 modules_install: _modinst_ _modinst_post
1229 @rm -rf $(MODLIB)/kernel
1230 @rm -f $(MODLIB)/source
1231 @mkdir -p $(MODLIB)/kernel
1232 @ln -s $(abspath $(srctree)) $(MODLIB)/source
1233 @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
1234 rm -f $(MODLIB)/build ; \
1235 ln -s $(CURDIR) $(MODLIB)/build ; \
1237 @cp -f $(objtree)/modules.order $(MODLIB)/
1238 @cp -f $(objtree)/modules.builtin $(MODLIB)/
1239 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1241 # This depmod is only for convenience to give the initial
1242 # boot a modules.dep even before / is mounted read-write. However the
1243 # boot script depmod is the master version.
1244 PHONY += _modinst_post
1245 _modinst_post: _modinst_
1248 ifeq ($(CONFIG_MODULE_SIG), y)
1249 PHONY += modules_sign
1251 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1254 else # CONFIG_MODULES
1256 # Modules not configured
1257 # ---------------------------------------------------------------------------
1259 PHONY += modules modules_install
1260 modules modules_install:
1262 @echo >&2 "The present kernel configuration has modules disabled."
1263 @echo >&2 "Type 'make config' and enable loadable module support."
1264 @echo >&2 "Then build a kernel with module support enabled."
1268 endif # CONFIG_MODULES
1271 # Cleaning is done on three levels.
1272 # make clean Delete most generated files
1273 # Leave enough to build external modules
1274 # make mrproper Delete the current configuration, and all generated files
1275 # make distclean Remove editor backup files, patch leftover files and the like
1277 # Directories & files removed with 'make clean'
1278 CLEAN_DIRS += $(MODVERDIR)
1280 # Directories & files removed with 'make mrproper'
1281 MRPROPER_DIRS += include/config usr/include include/generated \
1282 arch/*/include/generated .tmp_objdiff
1283 MRPROPER_FILES += .config .config.old .version \
1284 Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
1285 signing_key.pem signing_key.priv signing_key.x509 \
1286 x509.genkey extra_certificates signing_key.x509.keyid \
1287 signing_key.x509.signer vmlinux-gdb.py
1289 # clean - Delete most, but leave enough to build external modules
1291 clean: rm-dirs := $(CLEAN_DIRS)
1292 clean: rm-files := $(CLEAN_FILES)
1293 clean-dirs := $(addprefix _clean_, . $(vmlinux-alldirs) Documentation samples)
1295 PHONY += $(clean-dirs) clean archclean vmlinuxclean
1297 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1300 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1301 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1303 clean: archclean vmlinuxclean
1305 # mrproper - Delete all generated files, including .config
1307 mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS))
1308 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1309 mrproper-dirs := $(addprefix _mrproper_,scripts)
1311 PHONY += $(mrproper-dirs) mrproper archmrproper
1313 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1315 mrproper: clean archmrproper $(mrproper-dirs)
1324 @find $(srctree) $(RCS_FIND_IGNORE) \
1325 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1326 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1327 -o -name 'core' \) \
1328 -type f -print | xargs rm -f
1331 # Packaging of the kernel to various formats
1332 # ---------------------------------------------------------------------------
1333 # rpm target kept for backward compatibility
1334 package-dir := scripts/package
1337 $(Q)$(MAKE) $(build)=$(package-dir) $@
1338 %pkg: include/config/kernel.release FORCE
1339 $(Q)$(MAKE) $(build)=$(package-dir) $@
1341 @echo " WARNING: \"rpm\" target will be removed after Linux 4.18"
1342 @echo " Please use \"rpm-pkg\" instead."
1345 # Brief documentation of the typical targets used
1346 # ---------------------------------------------------------------------------
1348 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1349 boards := $(sort $(notdir $(boards)))
1350 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1351 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1355 @echo 'Cleaning targets:'
1356 @echo ' clean - Remove most generated files but keep the config and'
1357 @echo ' enough build support to build external modules'
1358 @echo ' mrproper - Remove all generated files + config + various backup files'
1359 @echo ' distclean - mrproper + remove editor backup and patch files'
1361 @echo 'Configuration targets:'
1362 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1364 @echo 'Other generic targets:'
1365 @echo ' all - Build all targets marked with [*]'
1366 @echo '* vmlinux - Build the bare kernel'
1367 @echo '* modules - Build all modules'
1368 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1369 @echo ' dir/ - Build all files in dir and below'
1370 @echo ' dir/file.[ois] - Build specified target only'
1371 @echo ' dir/file.ll - Build the LLVM assembly file'
1372 @echo ' (requires compiler support for LLVM assembly generation)'
1373 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1374 @echo ' (requires a recent binutils and recent build (System.map))'
1375 @echo ' dir/file.ko - Build module including final link'
1376 @echo ' modules_prepare - Set up for building external modules'
1377 @echo ' tags/TAGS - Generate tags file for editors'
1378 @echo ' cscope - Generate cscope index'
1379 @echo ' gtags - Generate GNU GLOBAL index'
1380 @echo ' kernelrelease - Output the release version string (use with make -s)'
1381 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1382 @echo ' image_name - Output the image name (use with make -s)'
1383 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1384 echo ' (default: $(INSTALL_HDR_PATH))'; \
1386 @echo 'Static analysers:'
1387 @echo ' checkstack - Generate a list of stack hogs'
1388 @echo ' namespacecheck - Name space analysis on compiled kernel'
1389 @echo ' versioncheck - Sanity check on version.h usage'
1390 @echo ' includecheck - Check for duplicate included header files'
1391 @echo ' export_report - List the usages of all exported symbols'
1392 @echo ' headers_check - Sanity check on exported headers'
1393 @echo ' headerdep - Detect inclusion cycles in headers'
1394 @echo ' coccicheck - Check with Coccinelle'
1396 @echo 'Kernel selftest:'
1397 @echo ' kselftest - Build and run kernel selftest (run as root)'
1398 @echo ' Build, install, and boot kernel before'
1399 @echo ' running kselftest on it'
1400 @echo ' kselftest-clean - Remove all generated kselftest files'
1401 @echo ' kselftest-merge - Merge all the config dependencies of kselftest to existing'
1404 @echo 'Userspace tools targets:'
1405 @echo ' use "make tools/help"'
1406 @echo ' or "cd tools; make help"'
1408 @echo 'Kernel packaging:'
1409 @$(MAKE) $(build)=$(package-dir) help
1411 @echo 'Documentation targets:'
1412 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1414 @echo 'Architecture specific targets ($(SRCARCH)):'
1415 @$(if $(archhelp),$(archhelp),\
1416 echo ' No architecture specific help defined for $(SRCARCH)')
1419 $(foreach b, $(boards), \
1420 printf " %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1422 @$(if $(board-dirs), \
1423 $(foreach b, $(board-dirs), \
1424 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1425 printf " %-16s - Show all of the above\\n" help-boards; \
1428 @echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1429 @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
1430 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1431 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK (sparse by default)'
1432 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1433 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1434 @echo ' make W=n [targets] Enable extra gcc checks, n=1,2,3 where'
1435 @echo ' 1: warnings which may be relevant and do not occur too often'
1436 @echo ' 2: warnings which occur quite often but may still be relevant'
1437 @echo ' 3: more obscure warnings, can most likely be ignored'
1438 @echo ' Multiple levels can be combined with W=12 or W=123'
1440 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1441 @echo 'For further info see the ./README file'
1444 help-board-dirs := $(addprefix help-,$(board-dirs))
1446 help-boards: $(help-board-dirs)
1448 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1450 $(help-board-dirs): help-%:
1451 @echo 'Architecture specific targets ($(SRCARCH) $*):'
1452 @$(if $(boards-per-dir), \
1453 $(foreach b, $(boards-per-dir), \
1454 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1458 # Documentation targets
1459 # ---------------------------------------------------------------------------
1460 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1461 linkcheckdocs dochelp refcheckdocs
1462 PHONY += $(DOC_TARGETS)
1463 $(DOC_TARGETS): scripts_basic FORCE
1464 $(Q)$(MAKE) $(build)=Documentation $@
1466 else # KBUILD_EXTMOD
1469 # External module support.
1470 # When building external modules the kernel used as basis is considered
1471 # read-only, and no consistency checks are made and the make
1472 # system is not used on the basis kernel. If updates are required
1473 # in the basis kernel ordinary make commands (without M=...) must
1476 # The following are the only valid targets when building external
1478 # make M=dir clean Delete all automatically generated files
1479 # make M=dir modules Make all modules in specified dir
1480 # make M=dir Same as 'make M=dir modules'
1481 # make M=dir modules_install
1482 # Install the modules built in the module directory
1483 # Assumes install directory is already created
1485 # We are always building modules
1487 PHONY += crmodverdir
1491 PHONY += $(objtree)/Module.symvers
1492 $(objtree)/Module.symvers:
1493 @test -e $(objtree)/Module.symvers || ( \
1495 echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1496 echo " is missing; modules will have no dependencies and modversions."; \
1499 module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
1500 PHONY += $(module-dirs) modules
1501 $(module-dirs): crmodverdir $(objtree)/Module.symvers
1502 $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
1504 modules: $(module-dirs)
1505 @$(kecho) ' Building modules, stage 2.';
1506 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1508 PHONY += modules_install
1509 modules_install: _emodinst_ _emodinst_post
1511 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1514 $(Q)mkdir -p $(MODLIB)/$(install-dir)
1515 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1517 PHONY += _emodinst_post
1518 _emodinst_post: _emodinst_
1521 clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))
1523 PHONY += $(clean-dirs) clean
1525 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1527 clean: rm-dirs := $(MODVERDIR)
1528 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1532 @echo ' Building external modules.'
1533 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1535 @echo ' modules - default target, build the module(s)'
1536 @echo ' modules_install - install the module'
1537 @echo ' clean - remove generated files in module directory only'
1541 PHONY += prepare scripts
1544 endif # KBUILD_EXTMOD
1546 clean: $(clean-dirs)
1549 @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1550 \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1551 -o -name '*.ko.*' -o -name '*.dtb' -o -name '*.dtb.S' \
1552 -o -name '*.dwo' -o -name '*.lst' \
1554 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1555 -o -name '*.symtypes' -o -name 'modules.order' \
1556 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1557 -o -name .cache.mk \
1558 -o -name '*.c.[012]*.*' \
1560 -o -name '*.gcno' \) -type f -print | xargs rm -f
1562 # Generate tags for editors
1563 # ---------------------------------------------------------------------------
1564 quiet_cmd_tags = GEN $@
1565 cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
1567 tags TAGS cscope gtags: FORCE
1570 # Scripts to check various things for consistency
1571 # ---------------------------------------------------------------------------
1573 PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1576 find $(srctree)/* $(RCS_FIND_IGNORE) \
1577 -name '*.[hcS]' -type f -print | sort \
1578 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1581 find $(srctree)/* $(RCS_FIND_IGNORE) \
1582 -name '*.[hcS]' -type f -print | sort \
1583 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1586 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1589 $(PERL) $(srctree)/scripts/namespace.pl
1592 $(PERL) $(srctree)/scripts/export_report.pl
1594 endif #ifeq ($(config-targets),1)
1595 endif #ifeq ($(mixed-targets),1)
1597 PHONY += checkstack kernelrelease kernelversion image_name
1599 # UML needs a little special treatment here. It wants to use the host
1600 # toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
1601 # else wants $(ARCH), including people doing cross-builds, which means
1602 # that $(SUBARCH) doesn't work here.
1604 CHECKSTACK_ARCH := $(SUBARCH)
1606 CHECKSTACK_ARCH := $(ARCH)
1609 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1610 $(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1613 @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1616 @echo $(KERNELVERSION)
1619 @echo $(KBUILD_IMAGE)
1621 # Clear a bunch of variables before executing the submake
1623 $(Q)mkdir -p $(objtree)/tools
1624 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/
1627 $(Q)mkdir -p $(objtree)/tools
1628 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/ $*
1631 # ---------------------------------------------------------------------------
1632 # Single targets are compatible with:
1633 # - build with mixed source and output
1634 # - build with separate output dir 'make O=...'
1635 # - external modules
1637 # target-dir => where to store outputfile
1638 # build-dir => directory in kernel source tree to use
1640 ifeq ($(KBUILD_EXTMOD),)
1641 build-dir = $(patsubst %/,%,$(dir $@))
1642 target-dir = $(dir $@)
1644 zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
1645 build-dir = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
1646 target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@))
1649 %.s: %.c prepare scripts FORCE
1650 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1651 %.i: %.c prepare scripts FORCE
1652 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1653 %.o: %.c prepare scripts FORCE
1654 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1655 %.lst: %.c prepare scripts FORCE
1656 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1657 %.s: %.S prepare scripts FORCE
1658 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1659 %.o: %.S prepare scripts FORCE
1660 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1661 %.symtypes: %.c prepare scripts FORCE
1662 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1663 %.ll: %.c prepare scripts FORCE
1664 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1667 /: prepare scripts FORCE
1669 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1670 $(build)=$(build-dir)
1671 # Make sure the latest headers are built for Documentation
1672 Documentation/ samples/: headers_install
1673 %/: prepare scripts FORCE
1675 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1676 $(build)=$(build-dir)
1677 %.ko: prepare scripts FORCE
1679 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1680 $(build)=$(build-dir) $(@:.ko=.o)
1681 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1683 # FIXME Should go into a make.lib or something
1684 # ===========================================================================
1686 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs)))
1687 cmd_rmdirs = rm -rf $(rm-dirs)
1689 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
1690 cmd_rmfiles = rm -f $(rm-files)
1692 # Run depmod only if we have System.map and depmod is executable
1693 quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
1694 cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1695 $(KERNELRELEASE) "$(patsubst y,_,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))"
1697 # Create temporary dir for module support files
1698 # clean it up only when building all modules
1699 cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
1700 $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
1702 # read all saved command lines
1704 cmd_files := $(wildcard .*.cmd $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd))
1706 ifneq ($(cmd_files),)
1707 $(cmd_files): ; # Do not try to update included dependency files
1708 include $(cmd_files)
1711 endif # skip-makefile
1716 # Declare the contents of the .PHONY variable as phony. We keep that
1717 # information in a variable so we can use it in if_changed and friends.