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 ($(KBUILD_VERBOSE),1)
89 # If the user is running make -s (silent mode), suppress echoing of
91 # make-4.0 (and later) keep single letter options in the 1st word of MAKEFLAGS.
93 ifeq ($(filter 3.%,$(MAKE_VERSION)),)
94 silence:=$(findstring s,$(firstword -$(MAKEFLAGS)))
96 silence:=$(findstring s,$(filter-out --%,$(MAKEFLAGS)))
104 export quiet Q KBUILD_VERBOSE
106 # kbuild supports saving output files in a separate directory.
107 # To locate output files in a separate directory two syntaxes are supported.
108 # In both cases the working directory must be the root of the kernel src.
110 # Use "make O=dir/to/store/output/files/"
112 # 2) Set KBUILD_OUTPUT
113 # Set the environment variable KBUILD_OUTPUT to point to the directory
114 # where the output files shall be placed.
115 # export KBUILD_OUTPUT=dir/to/store/output/files/
118 # The O= assignment takes precedence over the KBUILD_OUTPUT environment
121 # KBUILD_SRC is not intended to be used by the regular user (for now),
122 # it is set on invocation of make with KBUILD_OUTPUT or O= specified.
123 ifeq ($(KBUILD_SRC),)
125 # OK, Make called in directory where kernel src resides
126 # Do we want to locate output files in a separate directory?
127 ifeq ("$(origin O)", "command line")
128 KBUILD_OUTPUT := $(O)
131 # Cancel implicit rules on top Makefile
132 $(CURDIR)/Makefile Makefile: ;
134 ifneq ($(words $(subst :, ,$(CURDIR))), 1)
135 $(error main directory cannot contain spaces nor colons)
138 ifneq ($(KBUILD_OUTPUT),)
139 # check that the output directory actually exists
140 saved-output := $(KBUILD_OUTPUT)
141 KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
143 $(if $(KBUILD_OUTPUT),, \
144 $(error failed to create output directory "$(saved-output)"))
146 PHONY += $(MAKECMDGOALS) sub-make
148 $(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
151 # Invoke a second make in the output directory, passing relevant variables
153 $(Q)$(MAKE) -C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR) \
154 -f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS))
156 # Leave processing to above invocation of make
158 endif # ifneq ($(KBUILD_OUTPUT),)
159 endif # ifeq ($(KBUILD_SRC),)
161 # We process the rest of the Makefile if this is the final invocation of make
162 ifeq ($(skip-makefile),)
164 # Do not print "Entering directory ...",
165 # but we want to display it when entering to the output directory
166 # so that IDEs/editors are able to understand relative filenames.
167 MAKEFLAGS += --no-print-directory
169 # Call a source code checker (by default, "sparse") as part of the
172 # Use 'make C=1' to enable checking of only re-compiled files.
173 # Use 'make C=2' to enable checking of *all* source files, regardless
174 # of whether they are re-compiled or not.
176 # See the file "Documentation/dev-tools/sparse.rst" for more details,
177 # including where to get the "sparse" utility.
179 ifeq ("$(origin C)", "command line")
180 KBUILD_CHECKSRC = $(C)
182 ifndef KBUILD_CHECKSRC
186 # Use make M=dir to specify directory of external module to build
187 # Old syntax make ... SUBDIRS=$PWD is still supported
188 # Setting the environment variable KBUILD_EXTMOD take precedence
190 KBUILD_EXTMOD ?= $(SUBDIRS)
193 ifeq ("$(origin M)", "command line")
194 KBUILD_EXTMOD := $(M)
197 ifeq ($(KBUILD_SRC),)
198 # building in the source tree
201 ifeq ($(KBUILD_SRC)/,$(dir $(CURDIR)))
202 # building in a subdirectory of the source tree
205 srctree := $(KBUILD_SRC)
209 export KBUILD_CHECKSRC KBUILD_EXTMOD KBUILD_SRC
215 VPATH := $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))
217 export srctree objtree VPATH
219 # To make sure we do not include .config for any of the *config targets
220 # catch them early, and hand them over to scripts/kconfig/Makefile
221 # It is allowed to specify more targets when calling make, including
222 # mixing *config targets and build targets.
223 # For example 'make oldconfig all'.
224 # Detect when mixed targets is specified, and make a second invocation
225 # of make so .config is not included in this case either (for *config).
227 version_h := include/generated/uapi/linux/version.h
228 old_version_h := include/linux/version.h
230 no-dot-config-targets := clean mrproper distclean \
231 cscope gtags TAGS tags help% %docs check% coccicheck \
232 $(version_h) headers_% archheaders archscripts \
233 kernelversion %src-pkg
239 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
240 ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
245 ifeq ($(KBUILD_EXTMOD),)
246 ifneq ($(filter config %config,$(MAKECMDGOALS)),)
248 ifneq ($(words $(MAKECMDGOALS)),1)
253 # install and modules_install need also be processed one by one
254 ifneq ($(filter install,$(MAKECMDGOALS)),)
255 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
260 ifeq ($(mixed-targets),1)
261 # ===========================================================================
262 # We're called with mixed targets (*config and build targets).
263 # Handle them one by one.
265 PHONY += $(MAKECMDGOALS) __build_one_by_one
267 $(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
272 for i in $(MAKECMDGOALS); do \
273 $(MAKE) -f $(srctree)/Makefile $$i; \
278 # We need some generic definitions (do not try to remake the file).
279 scripts/Kbuild.include: ;
280 include scripts/Kbuild.include
282 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
283 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
284 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
285 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
287 # SUBARCH tells the usermode build what the underlying arch is. That is set
288 # first, and if a usermode build is happening, the "ARCH=um" on the command
289 # line overrides the setting of ARCH below. If a native build is happening,
290 # then ARCH is assigned, getting whatever value it gets normally, and
291 # SUBARCH is subsequently ignored.
293 SUBARCH := $(shell uname -m | sed -e s/i.86/x86/ -e s/x86_64/x86/ \
294 -e s/sun4u/sparc64/ \
295 -e s/arm.*/arm/ -e s/sa110/arm/ \
296 -e s/s390x/s390/ -e s/parisc64/parisc/ \
297 -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
298 -e s/sh[234].*/sh/ -e s/aarch64.*/arm64/ )
300 # Cross compiling and selecting different set of gcc/bin-utils
301 # ---------------------------------------------------------------------------
303 # When performing cross compilation for other architectures ARCH shall be set
304 # to the target architecture. (See arch/* for the possibilities).
305 # ARCH can be set during invocation of make:
307 # Another way is to have ARCH set in the environment.
308 # The default ARCH is the host where make is executed.
310 # CROSS_COMPILE specify the prefix used for all executables used
311 # during compilation. Only gcc and related bin-utils executables
312 # are prefixed with $(CROSS_COMPILE).
313 # CROSS_COMPILE can be set on the command line
314 # make CROSS_COMPILE=ia64-linux-
315 # Alternatively CROSS_COMPILE can be set in the environment.
316 # A third alternative is to store a setting in .config so that plain
317 # "make" in the configured kernel build directory always uses that.
318 # Default value for CROSS_COMPILE is not to prefix executables
319 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
321 CROSS_COMPILE ?= $(CONFIG_CROSS_COMPILE:"%"=%)
323 # Architecture as present in compile.h
324 UTS_MACHINE := $(ARCH)
327 # Additional ARCH settings for x86
331 ifeq ($(ARCH),x86_64)
335 # Additional ARCH settings for sparc
336 ifeq ($(ARCH),sparc32)
339 ifeq ($(ARCH),sparc64)
343 # Additional ARCH settings for sh
348 # Additional ARCH settings for tile
349 ifeq ($(ARCH),tilepro)
352 ifeq ($(ARCH),tilegx)
356 # Where to locate arch specific headers
357 hdr-arch := $(SRCARCH)
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 HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 \
374 -fomit-frame-pointer -std=gnu89 $(HOST_LFS_CFLAGS)
375 HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS)
376 HOSTLDFLAGS := $(HOST_LFS_LDFLAGS)
377 HOST_LOADLIBES := $(HOST_LFS_LIBS)
379 # Make variables (CC, etc...)
380 AS = $(CROSS_COMPILE)as
381 LD = $(CROSS_COMPILE)ld
382 CC = $(CROSS_COMPILE)gcc
384 AR = $(CROSS_COMPILE)ar
385 NM = $(CROSS_COMPILE)nm
386 STRIP = $(CROSS_COMPILE)strip
387 OBJCOPY = $(CROSS_COMPILE)objcopy
388 OBJDUMP = $(CROSS_COMPILE)objdump
390 GENKSYMS = scripts/genksyms/genksyms
391 INSTALLKERNEL := installkernel
397 CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
398 -Wbitwise -Wno-return-void $(CF)
407 # Use USERINCLUDE when you must reference the UAPI directories only.
409 -I$(srctree)/arch/$(hdr-arch)/include/uapi \
410 -I$(objtree)/arch/$(hdr-arch)/include/generated/uapi \
411 -I$(srctree)/include/uapi \
412 -I$(objtree)/include/generated/uapi \
413 -include $(srctree)/include/linux/kconfig.h
415 # Use LINUXINCLUDE when you must reference the include/ directory.
416 # Needed to be compatible with the O= option
418 -I$(srctree)/arch/$(hdr-arch)/include \
419 -I$(objtree)/arch/$(hdr-arch)/include/generated \
420 $(if $(KBUILD_SRC), -I$(srctree)/include) \
421 -I$(objtree)/include \
424 KBUILD_AFLAGS := -D__ASSEMBLY__
425 KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
426 -fno-strict-aliasing -fno-common -fshort-wchar \
427 -Werror-implicit-function-declaration \
428 -Wno-format-security \
430 KBUILD_CPPFLAGS := -D__KERNEL__
431 KBUILD_AFLAGS_KERNEL :=
432 KBUILD_CFLAGS_KERNEL :=
433 KBUILD_AFLAGS_MODULE := -DMODULE
434 KBUILD_CFLAGS_MODULE := -DMODULE
435 KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
437 GCC_PLUGINS_CFLAGS :=
440 export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC
441 export CPP AR NM STRIP OBJCOPY OBJDUMP HOSTLDFLAGS HOST_LOADLIBES
442 export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE
443 export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
445 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
446 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
447 export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN
448 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
449 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
450 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
451 export KBUILD_ARFLAGS
453 # When compiling out-of-tree modules, put MODVERDIR in the module
454 # tree rather than in the kernel tree. The kernel tree might
456 export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
458 # Files to ignore in find ... statements
460 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
461 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
463 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
464 --exclude CVS --exclude .pc --exclude .hg --exclude .git
466 # ===========================================================================
467 # Rules shared between *config targets and build targets
469 # Basic helpers built in scripts/basic/
470 PHONY += scripts_basic
472 $(Q)$(MAKE) $(build)=scripts/basic
473 $(Q)rm -f .tmp_quiet_recordmcount
475 # To avoid any implicit rule to kick in, define an empty command.
476 scripts/basic/%: scripts_basic ;
478 PHONY += outputmakefile
479 # outputmakefile generates a Makefile in the output directory, if using a
480 # separate output directory. This allows convenient use of make in the
483 ifneq ($(KBUILD_SRC),)
484 $(Q)ln -fsn $(srctree) source
485 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile \
486 $(srctree) $(objtree) $(VERSION) $(PATCHLEVEL)
489 ifeq ($(cc-name),clang)
490 ifneq ($(CROSS_COMPILE),)
491 CLANG_FLAGS += --target=$(notdir $(CROSS_COMPILE:%-=%))
492 GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
493 CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE))
494 GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..)
496 ifneq ($(GCC_TOOLCHAIN),)
497 CLANG_FLAGS += --gcc-toolchain=$(GCC_TOOLCHAIN)
499 CLANG_FLAGS += -no-integrated-as
500 CLANG_FLAGS += -Werror=unknown-warning-option
501 KBUILD_CFLAGS += $(CLANG_FLAGS)
502 KBUILD_AFLAGS += $(CLANG_FLAGS)
506 RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
507 RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
508 RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
509 RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
510 RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
511 RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
512 export RETPOLINE_CFLAGS
513 export RETPOLINE_VDSO_CFLAGS
515 ifeq ($(config-targets),1)
516 # ===========================================================================
517 # *config targets only - make sure prerequisites are updated, and descend
518 # in scripts/kconfig to make the *config target
520 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
521 # KBUILD_DEFCONFIG may point out an alternative default configuration
522 # used for 'make defconfig'
523 include arch/$(SRCARCH)/Makefile
524 export KBUILD_DEFCONFIG KBUILD_KCONFIG
526 config: scripts_basic outputmakefile FORCE
527 $(Q)$(MAKE) $(build)=scripts/kconfig $@
529 %config: scripts_basic outputmakefile FORCE
530 $(Q)$(MAKE) $(build)=scripts/kconfig $@
533 # ===========================================================================
534 # Build targets only - this includes vmlinux, arch specific targets, clean
535 # targets and others. In general all targets except *config targets.
537 # If building an external module we do not care about the all: rule
538 # but instead _all depend on modules
540 ifeq ($(KBUILD_EXTMOD),)
546 # Decide whether to build built-in, modular, or both.
547 # Normally, just do built-in.
552 # If we have only "make modules", don't compile built-in objects.
553 ifeq ($(MAKECMDGOALS),modules)
557 # If we have "make <whatever> modules", compile modules
558 # in addition to whatever we do anyway.
559 # Just "make" or "make all" shall build modules as well
561 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
565 ifeq ($(MAKECMDGOALS),)
569 export KBUILD_MODULES KBUILD_BUILTIN
571 ifeq ($(KBUILD_EXTMOD),)
572 # Additional helpers built in scripts/
573 # Carefully list dependencies so we do not try to build scripts twice
576 scripts: scripts_basic include/config/auto.conf include/config/tristate.conf \
577 asm-generic gcc-plugins
578 $(Q)$(MAKE) $(build)=$(@)
580 # Objects we will link into vmlinux / subdirs we need to visit
582 drivers-y := drivers/ sound/ firmware/
587 endif # KBUILD_EXTMOD
589 ifeq ($(dot-config),1)
591 -include include/config/auto.conf
593 ifeq ($(KBUILD_EXTMOD),)
594 # Read in dependencies to all Kconfig* files, make sure to run
595 # oldconfig if changes are detected.
596 -include include/config/auto.conf.cmd
598 # To avoid any implicit rule to kick in, define an empty command
599 $(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;
601 # If .config is newer than include/config/auto.conf, someone tinkered
602 # with it and forgot to run make oldconfig.
603 # if auto.conf.cmd is missing then we are probably in a cleaned tree so
604 # we execute the config step to be sure to catch updated Kconfig files
605 include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
606 $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig
608 # external modules needs include/generated/autoconf.h and include/config/auto.conf
609 # but do not care if they are up-to-date. Use auto.conf to trigger the test
610 PHONY += include/config/auto.conf
612 include/config/auto.conf:
613 $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
615 echo >&2 " ERROR: Kernel configuration is invalid."; \
616 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
617 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
621 endif # KBUILD_EXTMOD
624 # Dummy target needed, because used as prerequisite
625 include/config/auto.conf: ;
626 endif # $(dot-config)
628 # For the kernel to actually contain only the needed exported symbols,
629 # we have to build modules as well to determine what those symbols are.
630 # (this can be evaluated only once include/config/auto.conf has been included)
631 ifdef CONFIG_TRIM_UNUSED_KSYMS
635 # The all: target is the default when no target is given on the
637 # This allow a user to issue only 'make' to build a kernel including modules
638 # Defaults to vmlinux, but the arch makefile usually adds further targets
641 KBUILD_CFLAGS += $(call cc-option,-fno-PIE)
642 KBUILD_AFLAGS += $(call cc-option,-fno-PIE)
643 CFLAGS_GCOV := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,)
644 CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,)
645 export CFLAGS_GCOV CFLAGS_KCOV
647 # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
648 # values of the respective KBUILD_* variables
652 include arch/$(SRCARCH)/Makefile
654 KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
655 KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
656 KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
657 KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
658 KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context)
659 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
660 KBUILD_CFLAGS += $(call cc-disable-warning, attribute-alias)
662 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
668 # Tell gcc to never replace conditional load with a non-conditional one
669 KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
670 KBUILD_CFLAGS += $(call cc-option,-fno-allow-store-data-races)
672 # check for 'asm goto'
673 ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y)
674 KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
675 KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO
678 include scripts/Makefile.gcc-plugins
680 ifdef CONFIG_READABLE_ASM
681 # Disable optimizations that make assembler listings hard to read.
682 # reorder blocks reorders the control in the function
683 # ipa clone creates specialized cloned functions
684 # partial inlining inlines only parts of functions
685 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
686 $(call cc-option,-fno-ipa-cp-clone,) \
687 $(call cc-option,-fno-partial-inlining)
690 ifneq ($(CONFIG_FRAME_WARN),0)
691 KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
694 # This selects the stack protector compiler flag. Testing it is delayed
695 # until after .config has been reprocessed, in the prepare-compiler-check
697 ifdef CONFIG_CC_STACKPROTECTOR_REGULAR
698 stackp-flag := -fstack-protector
699 stackp-name := REGULAR
701 ifdef CONFIG_CC_STACKPROTECTOR_STRONG
702 stackp-flag := -fstack-protector-strong
703 stackp-name := STRONG
705 # Force off for distro compilers that enable stack protector by default.
706 stackp-flag := $(call cc-option, -fno-stack-protector)
709 # Find arch-specific stack protector compiler sanity-checking script.
710 ifdef CONFIG_CC_STACKPROTECTOR
711 stackp-path := $(srctree)/scripts/gcc-$(SRCARCH)_$(BITS)-has-stack-protector.sh
712 stackp-check := $(wildcard $(stackp-path))
714 KBUILD_CFLAGS += $(stackp-flag)
716 ifeq ($(cc-name),clang)
717 KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
718 KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
719 KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
720 # Quiet clang warning: comparison of unsigned expression < 0 is always false
721 KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
722 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
723 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
724 # See modpost pattern 2
725 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
726 KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
729 # These warnings generated too much noise in a regular build.
730 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
731 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
733 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
734 ifdef CONFIG_FRAME_POINTER
735 KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
737 # Some targets (ARM with Thumb2, for example), can't be built with frame
738 # pointers. For those, we don't have FUNCTION_TRACER automatically
739 # select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
740 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
741 # -fomit-frame-pointer with FUNCTION_TRACER.
742 ifndef CONFIG_FUNCTION_TRACER
743 KBUILD_CFLAGS += -fomit-frame-pointer
747 KBUILD_CFLAGS += $(call cc-option, -fno-var-tracking-assignments)
749 ifdef CONFIG_DEBUG_INFO
750 ifdef CONFIG_DEBUG_INFO_SPLIT
751 KBUILD_CFLAGS += $(call cc-option, -gsplit-dwarf, -g)
755 KBUILD_AFLAGS += -Wa,-gdwarf-2
757 ifdef CONFIG_DEBUG_INFO_DWARF4
758 KBUILD_CFLAGS += $(call cc-option, -gdwarf-4,)
761 ifdef CONFIG_DEBUG_INFO_REDUCED
762 KBUILD_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
763 $(call cc-option,-fno-var-tracking)
766 ifdef CONFIG_FUNCTION_TRACER
767 ifndef CC_FLAGS_FTRACE
768 CC_FLAGS_FTRACE := -pg
770 ifdef CONFIG_FTRACE_MCOUNT_RECORD
771 # gcc 5 supports generating the mcount tables directly
772 ifeq ($(call cc-option-yn,-mrecord-mcount),y)
773 CC_FLAGS_FTRACE += -mrecord-mcount
774 export CC_USING_RECORD_MCOUNT := 1
777 export CC_FLAGS_FTRACE
778 ifdef CONFIG_HAVE_FENTRY
779 CC_USING_FENTRY := $(call cc-option, -mfentry -DCC_USING_FENTRY)
781 KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_USING_FENTRY)
782 KBUILD_AFLAGS += $(CC_USING_FENTRY)
783 ifdef CONFIG_DYNAMIC_FTRACE
784 ifdef CONFIG_HAVE_C_RECORDMCOUNT
785 BUILD_C_RECORDMCOUNT := y
786 export BUILD_C_RECORDMCOUNT
791 # We trigger additional mismatches with less inlining
792 ifdef CONFIG_DEBUG_SECTION_MISMATCH
793 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
796 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
797 KBUILD_CFLAGS += $(call cc-option,-ffunction-sections,)
798 KBUILD_CFLAGS += $(call cc-option,-fdata-sections,)
801 # arch Makefile may override CC so keep this after arch Makefile is included
802 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
803 CHECKFLAGS += $(NOSTDINC_FLAGS)
805 # warn about C99 declaration after statement
806 KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
808 # disable pointer signed / unsigned warnings in gcc 4.0
809 KBUILD_CFLAGS += $(call cc-disable-warning, pointer-sign)
811 # disable stringop warnings in gcc 8+
812 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
814 # We'll want to enable this eventually, but it's not going away for 5.7 at least
815 KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds)
816 KBUILD_CFLAGS += $(call cc-disable-warning, array-bounds)
817 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
819 # Another good warning that we'll want to enable eventually
820 KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
822 # Enabled with W=2, disabled by default as noisy
823 KBUILD_CFLAGS += $(call cc-disable-warning, maybe-uninitialized)
825 # disable invalid "can't wrap" optimizations for signed / pointers
826 KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
828 # clang sets -fmerge-all-constants by default as optimization, but this
829 # is non-conforming behavior for C and in fact breaks the kernel, so we
830 # need to disable it here generally.
831 KBUILD_CFLAGS += $(call cc-option,-fno-merge-all-constants)
833 # for gcc -fno-merge-all-constants disables everything, but it is fine
834 # to have actual conforming behavior enabled.
835 KBUILD_CFLAGS += $(call cc-option,-fmerge-constants)
837 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
838 KBUILD_CFLAGS += $(call cc-option,-fno-stack-check,)
840 # conserve stack if available
841 KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
843 # disallow errors like 'EXPORT_GPL(foo);' with missing header
844 KBUILD_CFLAGS += $(call cc-option,-Werror=implicit-int)
846 # require functions to have arguments in prototypes, not empty 'int foo()'
847 KBUILD_CFLAGS += $(call cc-option,-Werror=strict-prototypes)
849 # Prohibit date/time macros, which would make the build non-deterministic
850 KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
852 # enforce correct pointer usage
853 KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
855 # Require designated initializers for all marked structures
856 KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
858 # change __FILE__ to the relative path from the srctree
859 KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
861 # use the deterministic mode of AR if available
862 KBUILD_ARFLAGS := $(call ar-option,D)
864 include scripts/Makefile.kasan
865 include scripts/Makefile.extrawarn
866 include scripts/Makefile.ubsan
868 # Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
870 KBUILD_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS)
871 KBUILD_AFLAGS += $(ARCH_AFLAGS) $(KAFLAGS)
872 KBUILD_CFLAGS += $(ARCH_CFLAGS) $(KCFLAGS)
874 # Use --build-id when available.
875 LDFLAGS_BUILD_ID := $(patsubst -Wl$(comma)%,%,\
876 $(call cc-ldoption, -Wl$(comma)--build-id,))
877 KBUILD_LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
878 LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
880 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
881 LDFLAGS_vmlinux += $(call ld-option, --gc-sections,)
884 LDFLAGS += -z noexecstack
885 LDFLAGS += $(call ld-option,--no-warn-rwx-segments)
887 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
888 LDFLAGS_vmlinux += $(call ld-option, -X,)
891 # Default kernel image to build when no specific target is given.
892 # KBUILD_IMAGE may be overruled on the command line or
893 # set in the environment
894 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
896 export KBUILD_IMAGE ?= vmlinux
899 # INSTALL_PATH specifies where to place the updated kernel and system map
900 # images. Default is /boot, but you can set it to other values
901 export INSTALL_PATH ?= /boot
904 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
905 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
906 # an argument if needed. Otherwise it defaults to the kernel install path
908 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
911 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
912 # relocations required by build roots. This is not defined in the
913 # makefile but the argument can be passed to make if needed.
916 MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
920 # INSTALL_MOD_STRIP, if defined, will cause modules to be
921 # stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
922 # the default option --strip-debug will be used. Otherwise,
923 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
925 ifdef INSTALL_MOD_STRIP
926 ifeq ($(INSTALL_MOD_STRIP),1)
927 mod_strip_cmd = $(STRIP) --strip-debug
929 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
930 endif # INSTALL_MOD_STRIP=1
933 endif # INSTALL_MOD_STRIP
936 # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
937 # after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
938 # or CONFIG_MODULE_COMPRESS_XZ.
940 mod_compress_cmd = true
941 ifdef CONFIG_MODULE_COMPRESS
942 ifdef CONFIG_MODULE_COMPRESS_GZIP
943 mod_compress_cmd = gzip -n -f
944 endif # CONFIG_MODULE_COMPRESS_GZIP
945 ifdef CONFIG_MODULE_COMPRESS_XZ
946 mod_compress_cmd = xz -f
947 endif # CONFIG_MODULE_COMPRESS_XZ
948 endif # CONFIG_MODULE_COMPRESS
949 export mod_compress_cmd
951 # Select initial ramdisk compression format, default is gzip(1).
952 # This shall be used by the dracut(8) tool while creating an initramfs image.
954 INITRD_COMPRESS-y := gzip
955 INITRD_COMPRESS-$(CONFIG_RD_BZIP2) := bzip2
956 INITRD_COMPRESS-$(CONFIG_RD_LZMA) := lzma
957 INITRD_COMPRESS-$(CONFIG_RD_XZ) := xz
958 INITRD_COMPRESS-$(CONFIG_RD_LZO) := lzo
959 INITRD_COMPRESS-$(CONFIG_RD_LZ4) := lz4
960 # do not export INITRD_COMPRESS, since we didn't actually
961 # choose a sane default compression above.
962 # export INITRD_COMPRESS := $(INITRD_COMPRESS-y)
964 ifdef CONFIG_MODULE_SIG_ALL
965 $(eval $(call config_filename,MODULE_SIG_KEY))
967 mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
973 HOST_LIBELF_LIBS = $(shell pkg-config libelf --libs 2>/dev/null || echo -lelf)
975 ifdef CONFIG_STACK_VALIDATION
976 has_libelf := $(call try-run,\
977 echo "int main() {}" | $(HOSTCC) -xc -o /dev/null $(HOST_LIBELF_LIBS) -,1,0)
978 ifeq ($(has_libelf),1)
979 objtool_target := tools/objtool FORCE
981 SKIP_STACK_VALIDATION := 1
982 export SKIP_STACK_VALIDATION
988 ifeq ($(KBUILD_EXTMOD),)
989 core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
991 vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
992 $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
993 $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
995 vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
996 $(init-) $(core-) $(drivers-) $(net-) $(libs-) $(virt-))))
998 init-y := $(patsubst %/, %/built-in.o, $(init-y))
999 core-y := $(patsubst %/, %/built-in.o, $(core-y))
1000 drivers-y := $(patsubst %/, %/built-in.o, $(drivers-y))
1001 net-y := $(patsubst %/, %/built-in.o, $(net-y))
1002 libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
1003 libs-y2 := $(filter-out %.a, $(patsubst %/, %/built-in.o, $(libs-y)))
1004 virt-y := $(patsubst %/, %/built-in.o, $(virt-y))
1006 # Externally visible symbols (used by link-vmlinux.sh)
1007 export KBUILD_VMLINUX_INIT := $(head-y) $(init-y)
1008 export KBUILD_VMLINUX_MAIN := $(core-y) $(libs-y2) $(drivers-y) $(net-y) $(virt-y)
1009 export KBUILD_VMLINUX_LIBS := $(libs-y1)
1010 export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
1011 export LDFLAGS_vmlinux
1012 # used by scripts/package/Makefile
1013 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools)
1015 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_INIT) $(KBUILD_VMLINUX_MAIN) $(KBUILD_VMLINUX_LIBS)
1017 # Include targets which we want to execute sequentially if the rest of the
1018 # kernel build went well. If CONFIG_TRIM_UNUSED_KSYMS is set, this might be
1019 # evaluated more than once.
1020 PHONY += vmlinux_prereq
1021 vmlinux_prereq: $(vmlinux-deps) FORCE
1022 ifdef CONFIG_HEADERS_CHECK
1023 $(Q)$(MAKE) -f $(srctree)/Makefile headers_check
1025 ifdef CONFIG_GDB_SCRIPTS
1026 $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1028 ifdef CONFIG_TRIM_UNUSED_KSYMS
1029 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1030 "$(MAKE) -f $(srctree)/Makefile vmlinux"
1033 # standalone target for easier testing
1034 include/generated/autoksyms.h: FORCE
1035 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh true
1037 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1039 # Final link of vmlinux with optional arch pass after final link
1040 cmd_link-vmlinux = \
1041 $(CONFIG_SHELL) $< $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) ; \
1042 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1044 vmlinux: scripts/link-vmlinux.sh vmlinux_prereq $(vmlinux-deps) FORCE
1045 +$(call if_changed,link-vmlinux)
1047 # Build samples along the rest of the kernel
1048 ifdef CONFIG_SAMPLES
1049 vmlinux-dirs += samples
1052 # The actual objects are generated when descending,
1053 # make sure no implicit rule kicks in
1054 $(sort $(vmlinux-deps)): $(vmlinux-dirs) ;
1056 # Handle descending into subdirectories listed in $(vmlinux-dirs)
1057 # Preset locale variables to speed up the build process. Limit locale
1058 # tweaks to this spot to avoid wrong language settings when running
1059 # make menuconfig etc.
1060 # Error messages still appears in the original language
1062 PHONY += $(vmlinux-dirs)
1063 $(vmlinux-dirs): prepare scripts
1064 $(Q)$(MAKE) $(build)=$@
1066 define filechk_kernel.release
1067 echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1070 # Store (new) KERNELRELEASE string in include/config/kernel.release
1071 include/config/kernel.release: include/config/auto.conf FORCE
1072 $(call filechk,kernel.release)
1075 # Things we need to do before we recursively start building the kernel
1076 # or the modules are listed in "prepare".
1077 # A multi level approach is used. prepareN is processed before prepareN-1.
1078 # archprepare is used in arch Makefiles and when processed asm symlink,
1079 # version.h and scripts_basic is processed / created.
1081 PHONY += prepare archprepare prepare1 prepare2 prepare3
1083 # prepare3 is used to check if we are building in a separate output directory,
1085 # 1) Check that make has not been executed in the kernel src $(srctree)
1086 prepare3: include/config/kernel.release
1087 ifneq ($(KBUILD_SRC),)
1088 @$(kecho) ' Using $(srctree) as source for kernel'
1089 $(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
1090 echo >&2 " $(srctree) is not clean, please run 'make mrproper'"; \
1091 echo >&2 " in the '$(srctree)' directory.";\
1096 # prepare2 creates a makefile if using a separate output directory.
1097 # From this point forward, .config has been reprocessed, so any rules
1098 # that need to depend on updated CONFIG_* values can be checked here.
1099 prepare2: prepare3 prepare-compiler-check outputmakefile asm-generic
1101 prepare1: prepare2 $(version_h) include/generated/utsrelease.h \
1102 include/config/auto.conf
1105 archprepare: archheaders archscripts prepare1 scripts_basic
1107 prepare0: archprepare gcc-plugins
1108 $(Q)$(MAKE) $(build)=.
1110 # All the preparing..
1111 prepare: prepare0 prepare-objtool
1113 # Support for using generic headers in asm-generic
1114 PHONY += asm-generic uapi-asm-generic
1115 asm-generic: uapi-asm-generic
1116 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
1117 src=asm obj=arch/$(SRCARCH)/include/generated/asm
1119 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
1120 src=uapi/asm obj=arch/$(SRCARCH)/include/generated/uapi/asm
1122 PHONY += prepare-objtool
1123 prepare-objtool: $(objtool_target)
1124 ifeq ($(SKIP_STACK_VALIDATION),1)
1125 ifdef CONFIG_UNWINDER_ORC
1126 @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1129 @echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1133 # Check for CONFIG flags that require compiler support. Abort the build
1134 # after .config has been processed, but before the kernel build starts.
1136 # For security-sensitive CONFIG options, we don't want to fallback and/or
1137 # silently change which compiler flags will be used, since that leads to
1138 # producing kernels with different security feature characteristics
1139 # depending on the compiler used. (For example, "But I selected
1140 # CC_STACKPROTECTOR_STRONG! Why did it build with _REGULAR?!")
1141 PHONY += prepare-compiler-check
1142 prepare-compiler-check: FORCE
1143 # Make sure compiler supports requested stack protector flag.
1145 ifeq ($(call cc-option, $(stackp-flag)),)
1146 @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1147 $(stackp-flag) not supported by compiler >&2 && exit 1
1150 # Make sure compiler does not have buggy stack-protector support.
1152 ifneq ($(shell $(CONFIG_SHELL) $(stackp-check) $(CC) $(KBUILD_CPPFLAGS) $(biarch)),y)
1153 @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1154 $(stackp-flag) available but compiler is broken >&2 && exit 1
1159 # Generate some files
1160 # ---------------------------------------------------------------------------
1162 # KERNELRELEASE can change from a few different places, meaning version.h
1163 # needs to be updated, so this check is forced on all builds
1166 define filechk_utsrelease.h
1167 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1168 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1171 (echo \#define UTS_RELEASE \"$(KERNELRELEASE)\";)
1174 define filechk_version.h
1175 (echo \#define LINUX_VERSION_CODE $(shell \
1176 expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 255); \
1177 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))';)
1180 $(version_h): $(srctree)/Makefile FORCE
1181 $(call filechk,version.h)
1182 $(Q)rm -f $(old_version_h)
1184 include/generated/utsrelease.h: include/config/kernel.release FORCE
1185 $(call filechk,utsrelease.h)
1189 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1190 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1192 # ---------------------------------------------------------------------------
1195 #Default location for installed headers
1196 export INSTALL_HDR_PATH = $(objtree)/usr
1198 # If we do an all arch process set dst to include/arch-$(hdr-arch)
1199 hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(hdr-arch), dst=include)
1201 PHONY += archheaders
1204 PHONY += archscripts
1208 __headers: $(version_h) scripts_basic uapi-asm-generic archheaders archscripts
1209 $(Q)$(MAKE) $(build)=scripts build_unifdef
1211 PHONY += headers_install_all
1212 headers_install_all:
1213 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh install
1215 PHONY += headers_install
1216 headers_install: __headers
1217 $(if $(wildcard $(srctree)/arch/$(hdr-arch)/include/uapi/asm/Kbuild),, \
1218 $(error Headers not exportable for the $(SRCARCH) architecture))
1219 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include
1220 $(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/uapi $(hdr-dst)
1222 PHONY += headers_check_all
1223 headers_check_all: headers_install_all
1224 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh check
1226 PHONY += headers_check
1227 headers_check: headers_install
1228 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include HDRCHECK=1
1229 $(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/uapi $(hdr-dst) HDRCHECK=1
1231 # ---------------------------------------------------------------------------
1236 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1238 PHONY += kselftest-clean
1240 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests clean
1242 PHONY += kselftest-merge
1244 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1245 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \
1246 -m $(objtree)/.config \
1247 $(srctree)/tools/testing/selftests/*/config
1248 +$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1250 # ---------------------------------------------------------------------------
1253 ifdef CONFIG_MODULES
1255 # By default, build modules as well
1259 # When we're building modules with modversions, we need to consider
1260 # the built-in objects during the descend as well, in order to
1261 # make sure the checksums are up to date before we record them.
1262 ifdef CONFIG_MODVERSIONS
1268 # A module can be listed more than once in obj-m resulting in
1269 # duplicate lines in modules.order files. Those are removed
1270 # using awk while concatenating to the final file.
1273 modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
1274 $(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
1275 @$(kecho) ' Building modules, stage 2.';
1276 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1278 modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
1279 $(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
1281 %/modules.builtin: include/config/auto.conf
1282 $(Q)$(MAKE) $(modbuiltin)=$*
1285 # Target to prepare building external modules
1286 PHONY += modules_prepare
1287 modules_prepare: prepare scripts
1289 # Target to install modules
1290 PHONY += modules_install
1291 modules_install: _modinst_ _modinst_post
1295 @rm -rf $(MODLIB)/kernel
1296 @rm -f $(MODLIB)/source
1297 @mkdir -p $(MODLIB)/kernel
1298 @ln -s $(abspath $(srctree)) $(MODLIB)/source
1299 @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
1300 rm -f $(MODLIB)/build ; \
1301 ln -s $(CURDIR) $(MODLIB)/build ; \
1303 @cp -f $(objtree)/modules.order $(MODLIB)/
1304 @cp -f $(objtree)/modules.builtin $(MODLIB)/
1305 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1307 # This depmod is only for convenience to give the initial
1308 # boot a modules.dep even before / is mounted read-write. However the
1309 # boot script depmod is the master version.
1310 PHONY += _modinst_post
1311 _modinst_post: _modinst_
1314 ifeq ($(CONFIG_MODULE_SIG), y)
1315 PHONY += modules_sign
1317 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1320 else # CONFIG_MODULES
1322 # Modules not configured
1323 # ---------------------------------------------------------------------------
1325 PHONY += modules modules_install
1326 modules modules_install:
1328 @echo >&2 "The present kernel configuration has modules disabled."
1329 @echo >&2 "Type 'make config' and enable loadable module support."
1330 @echo >&2 "Then build a kernel with module support enabled."
1334 endif # CONFIG_MODULES
1337 # Cleaning is done on three levels.
1338 # make clean Delete most generated files
1339 # Leave enough to build external modules
1340 # make mrproper Delete the current configuration, and all generated files
1341 # make distclean Remove editor backup files, patch leftover files and the like
1343 # Directories & files removed with 'make clean'
1344 CLEAN_DIRS += $(MODVERDIR)
1346 # Directories & files removed with 'make mrproper'
1347 MRPROPER_DIRS += include/config usr/include include/generated \
1348 arch/*/include/generated .tmp_objdiff
1349 MRPROPER_FILES += .config .config.old .version .old_version \
1350 Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
1351 signing_key.pem signing_key.priv signing_key.x509 \
1352 x509.genkey extra_certificates signing_key.x509.keyid \
1353 signing_key.x509.signer vmlinux-gdb.py
1355 # clean - Delete most, but leave enough to build external modules
1357 clean: rm-dirs := $(CLEAN_DIRS)
1358 clean: rm-files := $(CLEAN_FILES)
1359 clean-dirs := $(addprefix _clean_, . $(vmlinux-alldirs) Documentation samples)
1361 PHONY += $(clean-dirs) clean archclean vmlinuxclean
1363 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1366 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1367 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1369 clean: archclean vmlinuxclean
1371 # mrproper - Delete all generated files, including .config
1373 mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS))
1374 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1375 mrproper-dirs := $(addprefix _mrproper_,scripts)
1377 PHONY += $(mrproper-dirs) mrproper archmrproper
1379 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1381 mrproper: clean archmrproper $(mrproper-dirs)
1390 @find $(srctree) $(RCS_FIND_IGNORE) \
1391 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1392 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1393 -o -name 'core' \) \
1394 -type f -print | xargs rm -f
1397 # Packaging of the kernel to various formats
1398 # ---------------------------------------------------------------------------
1399 # rpm target kept for backward compatibility
1400 package-dir := scripts/package
1403 $(Q)$(MAKE) $(build)=$(package-dir) $@
1404 %pkg: include/config/kernel.release FORCE
1405 $(Q)$(MAKE) $(build)=$(package-dir) $@
1406 rpm: include/config/kernel.release FORCE
1407 $(Q)$(MAKE) $(build)=$(package-dir) $@
1410 # Brief documentation of the typical targets used
1411 # ---------------------------------------------------------------------------
1413 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1414 boards := $(sort $(notdir $(boards)))
1415 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1416 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1420 @echo 'Cleaning targets:'
1421 @echo ' clean - Remove most generated files but keep the config and'
1422 @echo ' enough build support to build external modules'
1423 @echo ' mrproper - Remove all generated files + config + various backup files'
1424 @echo ' distclean - mrproper + remove editor backup and patch files'
1426 @echo 'Configuration targets:'
1427 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1429 @echo 'Other generic targets:'
1430 @echo ' all - Build all targets marked with [*]'
1431 @echo '* vmlinux - Build the bare kernel'
1432 @echo '* modules - Build all modules'
1433 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1434 @echo ' dir/ - Build all files in dir and below'
1435 @echo ' dir/file.[ois] - Build specified target only'
1436 @echo ' dir/file.ll - Build the LLVM assembly file'
1437 @echo ' (requires compiler support for LLVM assembly generation)'
1438 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1439 @echo ' (requires a recent binutils and recent build (System.map))'
1440 @echo ' dir/file.ko - Build module including final link'
1441 @echo ' modules_prepare - Set up for building external modules'
1442 @echo ' tags/TAGS - Generate tags file for editors'
1443 @echo ' cscope - Generate cscope index'
1444 @echo ' gtags - Generate GNU GLOBAL index'
1445 @echo ' kernelrelease - Output the release version string (use with make -s)'
1446 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1447 @echo ' image_name - Output the image name (use with make -s)'
1448 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1449 echo ' (default: $(INSTALL_HDR_PATH))'; \
1451 @echo 'Static analysers:'
1452 @echo ' checkstack - Generate a list of stack hogs'
1453 @echo ' namespacecheck - Name space analysis on compiled kernel'
1454 @echo ' versioncheck - Sanity check on version.h usage'
1455 @echo ' includecheck - Check for duplicate included header files'
1456 @echo ' export_report - List the usages of all exported symbols'
1457 @echo ' headers_check - Sanity check on exported headers'
1458 @echo ' headerdep - Detect inclusion cycles in headers'
1459 @$(MAKE) -f $(srctree)/scripts/Makefile.help checker-help
1461 @echo 'Kernel selftest:'
1462 @echo ' kselftest - Build and run kernel selftest (run as root)'
1463 @echo ' Build, install, and boot kernel before'
1464 @echo ' running kselftest on it'
1465 @echo ' kselftest-clean - Remove all generated kselftest files'
1466 @echo ' kselftest-merge - Merge all the config dependencies of kselftest to existing'
1469 @echo 'Userspace tools targets:'
1470 @echo ' use "make tools/help"'
1471 @echo ' or "cd tools; make help"'
1473 @echo 'Kernel packaging:'
1474 @$(MAKE) $(build)=$(package-dir) help
1476 @echo 'Documentation targets:'
1477 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1479 @echo 'Architecture specific targets ($(SRCARCH)):'
1480 @$(if $(archhelp),$(archhelp),\
1481 echo ' No architecture specific help defined for $(SRCARCH)')
1484 $(foreach b, $(boards), \
1485 printf " %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1487 @$(if $(board-dirs), \
1488 $(foreach b, $(board-dirs), \
1489 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1490 printf " %-16s - Show all of the above\\n" help-boards; \
1493 @echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1494 @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
1495 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1496 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK (sparse by default)'
1497 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1498 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1499 @echo ' make W=n [targets] Enable extra gcc checks, n=1,2,3 where'
1500 @echo ' 1: warnings which may be relevant and do not occur too often'
1501 @echo ' 2: warnings which occur quite often but may still be relevant'
1502 @echo ' 3: more obscure warnings, can most likely be ignored'
1503 @echo ' Multiple levels can be combined with W=12 or W=123'
1505 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1506 @echo 'For further info see the ./README file'
1509 help-board-dirs := $(addprefix help-,$(board-dirs))
1511 help-boards: $(help-board-dirs)
1513 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1515 $(help-board-dirs): help-%:
1516 @echo 'Architecture specific targets ($(SRCARCH) $*):'
1517 @$(if $(boards-per-dir), \
1518 $(foreach b, $(boards-per-dir), \
1519 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1523 # Documentation targets
1524 # ---------------------------------------------------------------------------
1525 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs linkcheckdocs
1526 PHONY += $(DOC_TARGETS)
1527 $(DOC_TARGETS): scripts_basic FORCE
1528 $(Q)$(MAKE) $(build)=Documentation $@
1530 else # KBUILD_EXTMOD
1533 # External module support.
1534 # When building external modules the kernel used as basis is considered
1535 # read-only, and no consistency checks are made and the make
1536 # system is not used on the basis kernel. If updates are required
1537 # in the basis kernel ordinary make commands (without M=...) must
1540 # The following are the only valid targets when building external
1542 # make M=dir clean Delete all automatically generated files
1543 # make M=dir modules Make all modules in specified dir
1544 # make M=dir Same as 'make M=dir modules'
1545 # make M=dir modules_install
1546 # Install the modules built in the module directory
1547 # Assumes install directory is already created
1549 # We are always building modules
1552 PHONY += $(objtree)/Module.symvers
1553 $(objtree)/Module.symvers:
1554 @test -e $(objtree)/Module.symvers || ( \
1556 echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1557 echo " is missing; modules will have no dependencies and modversions."; \
1560 module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
1561 PHONY += $(module-dirs) modules
1562 $(module-dirs): prepare $(objtree)/Module.symvers
1563 $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
1565 modules: $(module-dirs)
1566 @$(kecho) ' Building modules, stage 2.';
1567 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1569 PHONY += modules_install
1570 modules_install: _emodinst_ _emodinst_post
1572 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1575 $(Q)mkdir -p $(MODLIB)/$(install-dir)
1576 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1578 PHONY += _emodinst_post
1579 _emodinst_post: _emodinst_
1582 clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))
1584 PHONY += $(clean-dirs) clean
1586 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1588 clean: rm-dirs := $(MODVERDIR)
1589 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1593 @echo ' Building external modules.'
1594 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1596 @echo ' modules - default target, build the module(s)'
1597 @echo ' modules_install - install the module'
1598 @echo ' clean - remove generated files in module directory only'
1602 PHONY += prepare scripts
1606 endif # KBUILD_EXTMOD
1608 clean: $(clean-dirs)
1611 @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1612 \( -name '*.[oas]' -o -name '*.ko' -o -name '.*.cmd' \
1616 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1617 -o -name '*.symtypes' -o -name 'modules.order' \
1618 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1619 -o -name '*.c.[012]*.*' \
1621 -o -name '*.gcno' \) -type f -print | xargs rm -f
1623 # Generate tags for editors
1624 # ---------------------------------------------------------------------------
1625 quiet_cmd_tags = GEN $@
1626 cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
1628 tags TAGS cscope gtags: FORCE
1631 # Scripts to check various things for consistency
1632 # ---------------------------------------------------------------------------
1634 PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1637 find $(srctree)/* $(RCS_FIND_IGNORE) \
1638 -name '*.[hcS]' -type f -print | sort \
1639 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1642 find $(srctree)/* $(RCS_FIND_IGNORE) \
1643 -name '*.[hcS]' -type f -print | sort \
1644 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1647 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1650 $(PERL) $(srctree)/scripts/namespace.pl
1653 $(PERL) $(srctree)/scripts/export_report.pl
1655 endif #ifeq ($(config-targets),1)
1656 endif #ifeq ($(mixed-targets),1)
1658 PHONY += checkstack kernelrelease kernelversion image_name
1660 # UML needs a little special treatment here. It wants to use the host
1661 # toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
1662 # else wants $(ARCH), including people doing cross-builds, which means
1663 # that $(SUBARCH) doesn't work here.
1665 CHECKSTACK_ARCH := $(SUBARCH)
1667 CHECKSTACK_ARCH := $(ARCH)
1670 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1671 $(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1674 @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1677 @echo $(KERNELVERSION)
1680 @echo $(KBUILD_IMAGE)
1682 # Clear a bunch of variables before executing the submake
1684 $(Q)mkdir -p $(objtree)/tools
1685 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/
1688 $(Q)mkdir -p $(objtree)/tools
1689 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/ $*
1692 # ---------------------------------------------------------------------------
1693 # Single targets are compatible with:
1694 # - build with mixed source and output
1695 # - build with separate output dir 'make O=...'
1696 # - external modules
1698 # target-dir => where to store outputfile
1699 # build-dir => directory in kernel source tree to use
1701 ifeq ($(KBUILD_EXTMOD),)
1702 build-dir = $(patsubst %/,%,$(dir $@))
1703 target-dir = $(dir $@)
1705 zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
1706 build-dir = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
1707 target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@))
1710 %.s: %.c prepare scripts FORCE
1711 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1712 %.i: %.c prepare scripts FORCE
1713 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1714 %.o: %.c prepare scripts FORCE
1715 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1716 %.lst: %.c prepare scripts FORCE
1717 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1718 %.s: %.S prepare scripts FORCE
1719 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1720 %.o: %.S prepare scripts FORCE
1721 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1722 %.symtypes: %.c prepare scripts FORCE
1723 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1724 %.ll: %.c prepare scripts FORCE
1725 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1728 /: prepare scripts FORCE
1729 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1730 $(build)=$(build-dir)
1731 # Make sure the latest headers are built for Documentation
1732 Documentation/ samples/: headers_install
1733 %/: prepare scripts FORCE
1734 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1735 $(build)=$(build-dir)
1736 %.ko: prepare scripts FORCE
1737 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1738 $(build)=$(build-dir) $(@:.ko=.o)
1739 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1741 # FIXME Should go into a make.lib or something
1742 # ===========================================================================
1744 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs)))
1745 cmd_rmdirs = rm -rf $(rm-dirs)
1747 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
1748 cmd_rmfiles = rm -f $(rm-files)
1750 # Run depmod only if we have System.map and depmod is executable
1751 quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
1752 cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1753 $(KERNELRELEASE) "$(patsubst y,_,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))"
1755 # Create temporary dir for module support files
1756 # clean it up only when building all modules
1757 cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
1758 $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
1760 # read all saved command lines
1762 targets := $(wildcard $(sort $(targets)))
1763 cmd_files := $(wildcard .*.cmd $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
1765 ifneq ($(cmd_files),)
1766 $(cmd_files): ; # Do not try to update included dependency files
1767 include $(cmd_files)
1770 endif # skip-makefile
1775 # Declare the contents of the .PHONY variable as phony. We keep that
1776 # information in a variable so we can use it in if_changed and friends.