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.a 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 clean-targets := %clean mrproper cleandocs
224 no-dot-config-targets := $(clean-targets) \
225 cscope gtags TAGS tags help% %docs check% coccicheck \
226 $(version_h) headers_% archheaders archscripts \
227 kernelversion %src-pkg
233 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
234 ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
239 ifeq ($(KBUILD_EXTMOD),)
240 ifneq ($(filter config %config,$(MAKECMDGOALS)),)
242 ifneq ($(words $(MAKECMDGOALS)),1)
248 # For "make -j clean all", "make -j mrproper defconfig all", etc.
249 ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
250 ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
255 # install and modules_install need also be processed one by one
256 ifneq ($(filter install,$(MAKECMDGOALS)),)
257 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
262 ifeq ($(mixed-targets),1)
263 # ===========================================================================
264 # We're called with mixed targets (*config and build targets).
265 # Handle them one by one.
267 PHONY += $(MAKECMDGOALS) __build_one_by_one
269 $(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
274 for i in $(MAKECMDGOALS); do \
275 $(MAKE) -f $(srctree)/Makefile $$i; \
280 # We need some generic definitions (do not try to remake the file).
281 scripts/Kbuild.include: ;
282 include scripts/Kbuild.include
284 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
285 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
286 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
287 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
289 # SUBARCH tells the usermode build what the underlying arch is. That is set
290 # first, and if a usermode build is happening, the "ARCH=um" on the command
291 # line overrides the setting of ARCH below. If a native build is happening,
292 # then ARCH is assigned, getting whatever value it gets normally, and
293 # SUBARCH is subsequently ignored.
295 SUBARCH := $(shell uname -m | sed -e s/i.86/x86/ -e s/x86_64/x86/ \
296 -e s/sun4u/sparc64/ \
297 -e s/arm.*/arm/ -e s/sa110/arm/ \
298 -e s/s390x/s390/ -e s/parisc64/parisc/ \
299 -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
300 -e s/sh[234].*/sh/ -e s/aarch64.*/arm64/ \
303 # Cross compiling and selecting different set of gcc/bin-utils
304 # ---------------------------------------------------------------------------
306 # When performing cross compilation for other architectures ARCH shall be set
307 # to the target architecture. (See arch/* for the possibilities).
308 # ARCH can be set during invocation of make:
310 # Another way is to have ARCH set in the environment.
311 # The default ARCH is the host where make is executed.
313 # CROSS_COMPILE specify the prefix used for all executables used
314 # during compilation. Only gcc and related bin-utils executables
315 # are prefixed with $(CROSS_COMPILE).
316 # CROSS_COMPILE can be set on the command line
317 # make CROSS_COMPILE=ia64-linux-
318 # Alternatively CROSS_COMPILE can be set in the environment.
319 # Default value for CROSS_COMPILE is not to prefix executables
320 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
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 KCONFIG_CONFIG ?= .config
349 export KCONFIG_CONFIG
351 # SHELL used by kbuild
352 CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
353 else if [ -x /bin/bash ]; then echo /bin/bash; \
354 else echo sh; fi ; fi)
356 HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS)
357 HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS)
358 HOST_LFS_LIBS := $(shell getconf LFS_LIBS)
362 HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 \
363 -fomit-frame-pointer -std=gnu89 $(HOST_LFS_CFLAGS)
364 HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS)
365 HOSTLDFLAGS := $(HOST_LFS_LDFLAGS)
366 HOST_LOADLIBES := $(HOST_LFS_LIBS)
368 # Make variables (CC, etc...)
369 AS = $(CROSS_COMPILE)as
370 LD = $(CROSS_COMPILE)ld
371 CC = $(CROSS_COMPILE)gcc
373 AR = $(CROSS_COMPILE)ar
374 NM = $(CROSS_COMPILE)nm
375 STRIP = $(CROSS_COMPILE)strip
376 OBJCOPY = $(CROSS_COMPILE)objcopy
377 OBJDUMP = $(CROSS_COMPILE)objdump
381 GENKSYMS = scripts/genksyms/genksyms
382 INSTALLKERNEL := installkernel
383 DEPMOD = /sbin/depmod
390 CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
391 -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
400 # Use USERINCLUDE when you must reference the UAPI directories only.
402 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
403 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
404 -I$(srctree)/include/uapi \
405 -I$(objtree)/include/generated/uapi \
406 -include $(srctree)/include/linux/kconfig.h
408 # Use LINUXINCLUDE when you must reference the include/ directory.
409 # Needed to be compatible with the O= option
411 -I$(srctree)/arch/$(SRCARCH)/include \
412 -I$(objtree)/arch/$(SRCARCH)/include/generated \
413 $(if $(KBUILD_SRC), -I$(srctree)/include) \
414 -I$(objtree)/include \
417 KBUILD_AFLAGS := -D__ASSEMBLY__
418 KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
419 -fno-strict-aliasing -fno-common -fshort-wchar \
420 -Werror-implicit-function-declaration \
421 -Wno-format-security \
423 KBUILD_CPPFLAGS := -D__KERNEL__
424 KBUILD_AFLAGS_KERNEL :=
425 KBUILD_CFLAGS_KERNEL :=
426 KBUILD_AFLAGS_MODULE := -DMODULE
427 KBUILD_CFLAGS_MODULE := -DMODULE
428 KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
430 GCC_PLUGINS_CFLAGS :=
432 export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC
433 export CPP AR NM STRIP OBJCOPY OBJDUMP HOSTLDFLAGS HOST_LOADLIBES
434 export MAKE LEX YACC AWK GENKSYMS INSTALLKERNEL PERL PYTHON PYTHON2 PYTHON3 UTS_MACHINE
435 export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
437 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
438 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
439 export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN
440 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
441 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
442 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
443 export KBUILD_ARFLAGS
445 export CC_VERSION_TEXT := $(shell $(CC) --version | head -n 1)
447 # When compiling out-of-tree modules, put MODVERDIR in the module
448 # tree rather than in the kernel tree. The kernel tree might
450 export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
452 # Files to ignore in find ... statements
454 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
455 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
457 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
458 --exclude CVS --exclude .pc --exclude .hg --exclude .git
460 # ===========================================================================
461 # Rules shared between *config targets and build targets
463 # Basic helpers built in scripts/basic/
464 PHONY += scripts_basic
466 $(Q)$(MAKE) $(build)=scripts/basic
467 $(Q)rm -f .tmp_quiet_recordmcount
469 # To avoid any implicit rule to kick in, define an empty command.
470 scripts/basic/%: scripts_basic ;
472 PHONY += outputmakefile
473 # outputmakefile generates a Makefile in the output directory, if using a
474 # separate output directory. This allows convenient use of make in the
477 ifneq ($(KBUILD_SRC),)
478 $(Q)ln -fsn $(srctree) source
479 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile \
480 $(srctree) $(objtree) $(VERSION) $(PATCHLEVEL)
483 ifeq ($(cc-name),clang)
484 ifneq ($(CROSS_COMPILE),)
485 CLANG_TARGET := --target=$(notdir $(CROSS_COMPILE:%-=%))
486 GCC_TOOLCHAIN := $(realpath $(dir $(shell which $(LD)))/..)
488 ifneq ($(GCC_TOOLCHAIN),)
489 CLANG_GCC_TC := --gcc-toolchain=$(GCC_TOOLCHAIN)
491 KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
492 KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
493 KBUILD_CFLAGS += $(call cc-option, -no-integrated-as)
494 KBUILD_AFLAGS += $(call cc-option, -no-integrated-as)
497 RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
498 RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
499 RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
500 export RETPOLINE_CFLAGS
502 KBUILD_CFLAGS += $(call cc-option,-fno-PIE)
503 KBUILD_AFLAGS += $(call cc-option,-fno-PIE)
505 # check for 'asm goto'
506 ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y)
507 CC_HAVE_ASM_GOTO := 1
508 KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
509 KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO
512 ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/cc-can-link.sh $(CC)), y)
517 ifeq ($(config-targets),1)
518 # ===========================================================================
519 # *config targets only - make sure prerequisites are updated, and descend
520 # in scripts/kconfig to make the *config target
522 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
523 # KBUILD_DEFCONFIG may point out an alternative default configuration
524 # used for 'make defconfig'
525 include arch/$(SRCARCH)/Makefile
526 export KBUILD_DEFCONFIG KBUILD_KCONFIG
528 config: scripts_basic outputmakefile FORCE
529 $(Q)$(MAKE) $(build)=scripts/kconfig $@
531 %config: scripts_basic outputmakefile FORCE
532 $(Q)$(MAKE) $(build)=scripts/kconfig $@
535 # ===========================================================================
536 # Build targets only - this includes vmlinux, arch specific targets, clean
537 # targets and others. In general all targets except *config targets.
539 # If building an external module we do not care about the all: rule
540 # but instead _all depend on modules
542 ifeq ($(KBUILD_EXTMOD),)
548 # Decide whether to build built-in, modular, or both.
549 # Normally, just do built-in.
554 # If we have only "make modules", don't compile built-in objects.
555 # When we're building modules with modversions, we need to consider
556 # the built-in objects during the descend as well, in order to
557 # make sure the checksums are up to date before we record them.
559 ifeq ($(MAKECMDGOALS),modules)
560 KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
563 # If we have "make <whatever> modules", compile modules
564 # in addition to whatever we do anyway.
565 # Just "make" or "make all" shall build modules as well
567 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
571 ifeq ($(MAKECMDGOALS),)
575 export KBUILD_MODULES KBUILD_BUILTIN
577 ifeq ($(KBUILD_EXTMOD),)
578 # Objects we will link into vmlinux / subdirs we need to visit
580 drivers-y := drivers/ sound/ firmware/
585 endif # KBUILD_EXTMOD
587 ifeq ($(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 # The actual configuration files used during the build are stored in
600 # include/generated/ and include/config/. Update them if .config is newer than
601 # include/config/auto.conf (which mirrors .config).
602 include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
603 $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
605 # external modules needs include/generated/autoconf.h and include/config/auto.conf
606 # but do not care if they are up-to-date. Use auto.conf to trigger the test
607 PHONY += include/config/auto.conf
609 include/config/auto.conf:
610 $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
612 echo >&2 " ERROR: Kernel configuration is invalid."; \
613 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
614 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
618 endif # KBUILD_EXTMOD
621 # Dummy target needed, because used as prerequisite
622 include/config/auto.conf: ;
623 endif # $(dot-config)
625 # The all: target is the default when no target is given on the
627 # This allow a user to issue only 'make' to build a kernel including modules
628 # Defaults to vmlinux, but the arch makefile usually adds further targets
631 CFLAGS_GCOV := -fprofile-arcs -ftest-coverage \
632 $(call cc-option,-fno-tree-loop-im) \
633 $(call cc-disable-warning,maybe-uninitialized,)
634 export CFLAGS_GCOV CFLAGS_KCOV
636 # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
637 # values of the respective KBUILD_* variables
641 include arch/$(SRCARCH)/Makefile
643 KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
644 KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
645 KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
646 KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
647 KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context)
649 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
650 KBUILD_CFLAGS += $(call cc-option,-Oz,-Os)
651 KBUILD_CFLAGS += $(call cc-disable-warning,maybe-uninitialized,)
653 ifdef CONFIG_PROFILE_ALL_BRANCHES
654 KBUILD_CFLAGS += -O2 $(call cc-disable-warning,maybe-uninitialized,)
660 KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \
661 $(call cc-disable-warning,maybe-uninitialized,))
663 # Tell gcc to never replace conditional load with a non-conditional one
664 KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
666 include scripts/Makefile.kcov
667 include scripts/Makefile.gcc-plugins
669 ifdef CONFIG_READABLE_ASM
670 # Disable optimizations that make assembler listings hard to read.
671 # reorder blocks reorders the control in the function
672 # ipa clone creates specialized cloned functions
673 # partial inlining inlines only parts of functions
674 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
675 $(call cc-option,-fno-ipa-cp-clone,) \
676 $(call cc-option,-fno-partial-inlining)
679 ifneq ($(CONFIG_FRAME_WARN),0)
680 KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
683 # This selects the stack protector compiler flag. Testing it is delayed
684 # until after .config has been reprocessed, in the prepare-compiler-check
686 ifdef CONFIG_CC_STACKPROTECTOR_AUTO
687 stackp-flag := $(call cc-option,-fstack-protector-strong,$(call cc-option,-fstack-protector))
690 ifdef CONFIG_CC_STACKPROTECTOR_REGULAR
691 stackp-flag := -fstack-protector
692 stackp-name := REGULAR
694 ifdef CONFIG_CC_STACKPROTECTOR_STRONG
695 stackp-flag := -fstack-protector-strong
696 stackp-name := STRONG
698 # If either there is no stack protector for this architecture or
699 # CONFIG_CC_STACKPROTECTOR_NONE is selected, we're done, and $(stackp-name)
700 # is empty, skipping all remaining stack protector tests.
702 # Force off for distro compilers that enable stack protector by default.
703 KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector)
707 # Find arch-specific stack protector compiler sanity-checking script.
709 ifneq ($(stackp-flag),)
710 stackp-path := $(srctree)/scripts/gcc-$(SRCARCH)_$(BITS)-has-stack-protector.sh
711 stackp-check := $(wildcard $(stackp-path))
712 # If the wildcard test matches a test script, run it to check functionality.
714 ifneq ($(shell $(CONFIG_SHELL) $(stackp-check) $(CC) $(KBUILD_CPPFLAGS) $(biarch)),y)
719 # If the stack protector is functional, enable code that depends on it.
720 KBUILD_CPPFLAGS += -DCONFIG_CC_STACKPROTECTOR
721 # Either we've already detected the flag (for AUTO) or we'll fail the
722 # build in the prepare-compiler-check rule (for specific flag).
723 KBUILD_CFLAGS += $(stackp-flag)
725 # We have to make sure stack protector is unconditionally disabled if
726 # the compiler is broken (in case we're going to continue the build in
728 KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector)
733 ifeq ($(cc-name),clang)
734 KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
735 KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
736 KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
737 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
738 # Quiet clang warning: comparison of unsigned expression < 0 is always false
739 KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
740 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
741 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
742 # See modpost pattern 2
743 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
744 KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
747 # These warnings generated too much noise in a regular build.
748 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
749 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
752 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
753 ifdef CONFIG_FRAME_POINTER
754 KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
756 # Some targets (ARM with Thumb2, for example), can't be built with frame
757 # pointers. For those, we don't have FUNCTION_TRACER automatically
758 # select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
759 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
760 # -fomit-frame-pointer with FUNCTION_TRACER.
761 ifndef CONFIG_FUNCTION_TRACER
762 KBUILD_CFLAGS += -fomit-frame-pointer
766 KBUILD_CFLAGS += $(call cc-option, -fno-var-tracking-assignments)
768 ifdef CONFIG_DEBUG_INFO
769 ifdef CONFIG_DEBUG_INFO_SPLIT
770 KBUILD_CFLAGS += $(call cc-option, -gsplit-dwarf, -g)
774 KBUILD_AFLAGS += -Wa,-gdwarf-2
776 ifdef CONFIG_DEBUG_INFO_DWARF4
777 KBUILD_CFLAGS += $(call cc-option, -gdwarf-4,)
780 ifdef CONFIG_DEBUG_INFO_REDUCED
781 KBUILD_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
782 $(call cc-option,-fno-var-tracking)
785 ifdef CONFIG_FUNCTION_TRACER
786 ifndef CC_FLAGS_FTRACE
787 CC_FLAGS_FTRACE := -pg
789 export CC_FLAGS_FTRACE
790 ifdef CONFIG_HAVE_FENTRY
791 CC_USING_FENTRY := $(call cc-option, -mfentry -DCC_USING_FENTRY)
793 KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_USING_FENTRY)
794 KBUILD_AFLAGS += $(CC_USING_FENTRY)
795 ifdef CONFIG_DYNAMIC_FTRACE
796 ifdef CONFIG_HAVE_C_RECORDMCOUNT
797 BUILD_C_RECORDMCOUNT := y
798 export BUILD_C_RECORDMCOUNT
803 # We trigger additional mismatches with less inlining
804 ifdef CONFIG_DEBUG_SECTION_MISMATCH
805 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
808 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
809 KBUILD_CFLAGS_KERNEL += $(call cc-option,-ffunction-sections,)
810 KBUILD_CFLAGS_KERNEL += $(call cc-option,-fdata-sections,)
813 # arch Makefile may override CC so keep this after arch Makefile is included
814 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
816 # warn about C99 declaration after statement
817 KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
819 # disable pointer signed / unsigned warnings in gcc 4.0
820 KBUILD_CFLAGS += $(call cc-disable-warning, pointer-sign)
822 # disable invalid "can't wrap" optimizations for signed / pointers
823 KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
825 # clang sets -fmerge-all-constants by default as optimization, but this
826 # is non-conforming behavior for C and in fact breaks the kernel, so we
827 # need to disable it here generally.
828 KBUILD_CFLAGS += $(call cc-option,-fno-merge-all-constants)
830 # for gcc -fno-merge-all-constants disables everything, but it is fine
831 # to have actual conforming behavior enabled.
832 KBUILD_CFLAGS += $(call cc-option,-fmerge-constants)
834 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
835 KBUILD_CFLAGS += $(call cc-option,-fno-stack-check,)
837 # conserve stack if available
838 KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
840 # disallow errors like 'EXPORT_GPL(foo);' with missing header
841 KBUILD_CFLAGS += $(call cc-option,-Werror=implicit-int)
843 # require functions to have arguments in prototypes, not empty 'int foo()'
844 KBUILD_CFLAGS += $(call cc-option,-Werror=strict-prototypes)
846 # Prohibit date/time macros, which would make the build non-deterministic
847 KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
849 # enforce correct pointer usage
850 KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
852 # Require designated initializers for all marked structures
853 KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
855 # change __FILE__ to the relative path from the srctree
856 KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
858 # use the deterministic mode of AR if available
859 KBUILD_ARFLAGS := $(call ar-option,D)
861 include scripts/Makefile.kasan
862 include scripts/Makefile.extrawarn
863 include scripts/Makefile.ubsan
865 # Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
867 KBUILD_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS)
868 KBUILD_AFLAGS += $(ARCH_AFLAGS) $(KAFLAGS)
869 KBUILD_CFLAGS += $(ARCH_CFLAGS) $(KCFLAGS)
871 # Use --build-id when available.
872 LDFLAGS_BUILD_ID := $(call ld-option, --build-id)
873 KBUILD_LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
874 LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
876 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
877 LDFLAGS_vmlinux += $(call ld-option, --gc-sections,)
880 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
881 LDFLAGS_vmlinux += $(call ld-option, -X,)
884 # insure the checker run with the right endianness
885 CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
887 # the checker needs the correct machine size
888 CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
890 # Default kernel image to build when no specific target is given.
891 # KBUILD_IMAGE may be overruled on the command line or
892 # set in the environment
893 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
895 export KBUILD_IMAGE ?= vmlinux
898 # INSTALL_PATH specifies where to place the updated kernel and system map
899 # images. Default is /boot, but you can set it to other values
900 export INSTALL_PATH ?= /boot
903 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
904 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
905 # an argument if needed. Otherwise it defaults to the kernel install path
907 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
910 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
911 # relocations required by build roots. This is not defined in the
912 # makefile but the argument can be passed to make if needed.
915 MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
919 # INSTALL_MOD_STRIP, if defined, will cause modules to be
920 # stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
921 # the default option --strip-debug will be used. Otherwise,
922 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
924 ifdef INSTALL_MOD_STRIP
925 ifeq ($(INSTALL_MOD_STRIP),1)
926 mod_strip_cmd = $(STRIP) --strip-debug
928 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
929 endif # INSTALL_MOD_STRIP=1
932 endif # INSTALL_MOD_STRIP
935 # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
936 # after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
937 # or CONFIG_MODULE_COMPRESS_XZ.
939 mod_compress_cmd = true
940 ifdef CONFIG_MODULE_COMPRESS
941 ifdef CONFIG_MODULE_COMPRESS_GZIP
942 mod_compress_cmd = gzip -n -f
943 endif # CONFIG_MODULE_COMPRESS_GZIP
944 ifdef CONFIG_MODULE_COMPRESS_XZ
945 mod_compress_cmd = xz -f
946 endif # CONFIG_MODULE_COMPRESS_XZ
947 endif # CONFIG_MODULE_COMPRESS
948 export mod_compress_cmd
950 # Select initial ramdisk compression format, default is gzip(1).
951 # This shall be used by the dracut(8) tool while creating an initramfs image.
953 INITRD_COMPRESS-y := gzip
954 INITRD_COMPRESS-$(CONFIG_RD_BZIP2) := bzip2
955 INITRD_COMPRESS-$(CONFIG_RD_LZMA) := lzma
956 INITRD_COMPRESS-$(CONFIG_RD_XZ) := xz
957 INITRD_COMPRESS-$(CONFIG_RD_LZO) := lzo
958 INITRD_COMPRESS-$(CONFIG_RD_LZ4) := lz4
959 # do not export INITRD_COMPRESS, since we didn't actually
960 # choose a sane default compression above.
961 # export INITRD_COMPRESS := $(INITRD_COMPRESS-y)
963 ifdef CONFIG_MODULE_SIG_ALL
964 $(eval $(call config_filename,MODULE_SIG_KEY))
966 mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
972 ifdef CONFIG_STACK_VALIDATION
973 has_libelf := $(call try-run,\
974 echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0)
975 ifeq ($(has_libelf),1)
976 objtool_target := tools/objtool FORCE
978 ifdef CONFIG_UNWINDER_ORC
979 $(error "Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel")
981 $(warning "Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel")
983 SKIP_STACK_VALIDATION := 1
984 export SKIP_STACK_VALIDATION
989 ifeq ($(KBUILD_EXTMOD),)
990 core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
992 vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
993 $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
994 $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
996 vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
997 $(init-) $(core-) $(drivers-) $(net-) $(libs-) $(virt-))))
999 init-y := $(patsubst %/, %/built-in.a, $(init-y))
1000 core-y := $(patsubst %/, %/built-in.a, $(core-y))
1001 drivers-y := $(patsubst %/, %/built-in.a, $(drivers-y))
1002 net-y := $(patsubst %/, %/built-in.a, $(net-y))
1003 libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
1004 libs-y2 := $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y)))
1005 virt-y := $(patsubst %/, %/built-in.a, $(virt-y))
1007 # Externally visible symbols (used by link-vmlinux.sh)
1008 export KBUILD_VMLINUX_INIT := $(head-y) $(init-y)
1009 export KBUILD_VMLINUX_MAIN := $(core-y) $(libs-y2) $(drivers-y) $(net-y) $(virt-y)
1010 export KBUILD_VMLINUX_LIBS := $(libs-y1)
1011 export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
1012 export LDFLAGS_vmlinux
1013 # used by scripts/package/Makefile
1014 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools)
1016 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_INIT) $(KBUILD_VMLINUX_MAIN) $(KBUILD_VMLINUX_LIBS)
1018 # Recurse until adjust_autoksyms.sh is satisfied
1019 PHONY += autoksyms_recursive
1020 autoksyms_recursive: $(vmlinux-deps)
1021 ifdef CONFIG_TRIM_UNUSED_KSYMS
1022 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1023 "$(MAKE) -f $(srctree)/Makefile vmlinux"
1026 # For the kernel to actually contain only the needed exported symbols,
1027 # we have to build modules as well to determine what those symbols are.
1028 # (this can be evaluated only once include/config/auto.conf has been included)
1029 ifdef CONFIG_TRIM_UNUSED_KSYMS
1033 autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1036 $(Q)mkdir -p $(dir $@)
1039 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1041 # Final link of vmlinux with optional arch pass after final link
1042 cmd_link-vmlinux = \
1043 $(CONFIG_SHELL) $< $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) ; \
1044 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1046 vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1047 ifdef CONFIG_HEADERS_CHECK
1048 $(Q)$(MAKE) -f $(srctree)/Makefile headers_check
1050 ifdef CONFIG_GDB_SCRIPTS
1051 $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1053 +$(call if_changed,link-vmlinux)
1055 # Build samples along the rest of the kernel
1056 ifdef CONFIG_SAMPLES
1057 vmlinux-dirs += samples
1060 # The actual objects are generated when descending,
1061 # make sure no implicit rule kicks in
1062 $(sort $(vmlinux-deps)): $(vmlinux-dirs) ;
1064 # Handle descending into subdirectories listed in $(vmlinux-dirs)
1065 # Preset locale variables to speed up the build process. Limit locale
1066 # tweaks to this spot to avoid wrong language settings when running
1067 # make menuconfig etc.
1068 # Error messages still appears in the original language
1070 PHONY += $(vmlinux-dirs)
1071 $(vmlinux-dirs): prepare scripts
1072 $(Q)$(MAKE) $(build)=$@ need-builtin=1
1074 define filechk_kernel.release
1075 echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1078 # Store (new) KERNELRELEASE string in include/config/kernel.release
1079 include/config/kernel.release: include/config/auto.conf FORCE
1080 $(call filechk,kernel.release)
1082 # Additional helpers built in scripts/
1083 # Carefully list dependencies so we do not try to build scripts twice
1086 scripts: scripts_basic include/config/auto.conf include/config/tristate.conf \
1087 asm-generic gcc-plugins $(autoksyms_h)
1088 $(Q)$(MAKE) $(build)=$(@)
1090 # Things we need to do before we recursively start building the kernel
1091 # or the modules are listed in "prepare".
1092 # A multi level approach is used. prepareN is processed before prepareN-1.
1093 # archprepare is used in arch Makefiles and when processed asm symlink,
1094 # version.h and scripts_basic is processed / created.
1096 # Listed in dependency order
1097 PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3
1099 # prepare3 is used to check if we are building in a separate output directory,
1101 # 1) Check that make has not been executed in the kernel src $(srctree)
1102 prepare3: include/config/kernel.release
1103 ifneq ($(KBUILD_SRC),)
1104 @$(kecho) ' Using $(srctree) as source for kernel'
1105 $(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
1106 echo >&2 " $(srctree) is not clean, please run 'make mrproper'"; \
1107 echo >&2 " in the '$(srctree)' directory.";\
1112 # prepare2 creates a makefile if using a separate output directory.
1113 # From this point forward, .config has been reprocessed, so any rules
1114 # that need to depend on updated CONFIG_* values can be checked here.
1115 prepare2: prepare3 prepare-compiler-check outputmakefile asm-generic
1117 prepare1: prepare2 $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1118 include/config/auto.conf
1121 archprepare: archheaders archscripts prepare1 scripts_basic
1123 prepare0: archprepare gcc-plugins
1124 $(Q)$(MAKE) $(build)=.
1126 # All the preparing..
1127 prepare: prepare0 prepare-objtool
1129 # Support for using generic headers in asm-generic
1130 PHONY += asm-generic uapi-asm-generic
1131 asm-generic: uapi-asm-generic
1132 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
1133 src=asm obj=arch/$(SRCARCH)/include/generated/asm
1135 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
1136 src=uapi/asm obj=arch/$(SRCARCH)/include/generated/uapi/asm
1138 PHONY += prepare-objtool
1139 prepare-objtool: $(objtool_target)
1141 # Check for CONFIG flags that require compiler support. Abort the build
1142 # after .config has been processed, but before the kernel build starts.
1144 # For security-sensitive CONFIG options, we don't want to fallback and/or
1145 # silently change which compiler flags will be used, since that leads to
1146 # producing kernels with different security feature characteristics
1147 # depending on the compiler used. (For example, "But I selected
1148 # CC_STACKPROTECTOR_STRONG! Why did it build with _REGULAR?!")
1149 PHONY += prepare-compiler-check
1150 prepare-compiler-check: FORCE
1151 # Make sure compiler supports requested stack protector flag.
1153 # Warn about CONFIG_CC_STACKPROTECTOR_AUTO having found no option.
1154 ifeq ($(stackp-flag),)
1155 @echo CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1156 Compiler does not support any known stack-protector >&2
1158 # Fail if specifically requested stack protector is missing.
1159 ifeq ($(call cc-option, $(stackp-flag)),)
1160 @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1161 $(stackp-flag) not supported by compiler >&2 && exit 1
1165 # Make sure compiler does not have buggy stack-protector support. If a
1166 # specific stack-protector was requested, fail the build, otherwise warn.
1168 ifeq ($(stackp-name),AUTO)
1169 @echo CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1170 $(stackp-flag) available but compiler is broken: disabling >&2
1172 @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1173 $(stackp-flag) available but compiler is broken >&2 && exit 1
1178 # Generate some files
1179 # ---------------------------------------------------------------------------
1181 # KERNELRELEASE can change from a few different places, meaning version.h
1182 # needs to be updated, so this check is forced on all builds
1185 define filechk_utsrelease.h
1186 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1187 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1190 (echo \#define UTS_RELEASE \"$(KERNELRELEASE)\";)
1193 define filechk_version.h
1194 (echo \#define LINUX_VERSION_CODE $(shell \
1195 expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
1196 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))';)
1199 $(version_h): $(srctree)/Makefile FORCE
1200 $(call filechk,version.h)
1201 $(Q)rm -f $(old_version_h)
1203 include/generated/utsrelease.h: include/config/kernel.release FORCE
1204 $(call filechk,utsrelease.h)
1208 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1209 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1211 # ---------------------------------------------------------------------------
1214 #Default location for installed headers
1215 export INSTALL_HDR_PATH = $(objtree)/usr
1217 # If we do an all arch process set dst to include/arch-$(SRCARCH)
1218 hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(SRCARCH), dst=include)
1220 PHONY += archheaders
1223 PHONY += archscripts
1227 __headers: $(version_h) scripts_basic uapi-asm-generic archheaders archscripts
1228 $(Q)$(MAKE) $(build)=scripts build_unifdef
1230 PHONY += headers_install_all
1231 headers_install_all:
1232 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh install
1234 PHONY += headers_install
1235 headers_install: __headers
1236 $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1237 $(error Headers not exportable for the $(SRCARCH) architecture))
1238 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include
1239 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst)
1241 PHONY += headers_check_all
1242 headers_check_all: headers_install_all
1243 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh check
1245 PHONY += headers_check
1246 headers_check: headers_install
1247 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include HDRCHECK=1
1248 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst) HDRCHECK=1
1250 # ---------------------------------------------------------------------------
1255 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1257 PHONY += kselftest-clean
1259 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests clean
1261 PHONY += kselftest-merge
1263 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1264 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \
1265 -m $(objtree)/.config \
1266 $(srctree)/tools/testing/selftests/*/config
1267 +$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1269 # ---------------------------------------------------------------------------
1272 ifdef CONFIG_MODULES
1274 # By default, build modules as well
1280 # A module can be listed more than once in obj-m resulting in
1281 # duplicate lines in modules.order files. Those are removed
1282 # using awk while concatenating to the final file.
1285 modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
1286 $(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
1287 @$(kecho) ' Building modules, stage 2.';
1288 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1290 modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
1291 $(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
1293 %/modules.builtin: include/config/auto.conf
1294 $(Q)$(MAKE) $(modbuiltin)=$*
1297 # Target to prepare building external modules
1298 PHONY += modules_prepare
1299 modules_prepare: prepare scripts
1301 # Target to install modules
1302 PHONY += modules_install
1303 modules_install: _modinst_ _modinst_post
1307 @rm -rf $(MODLIB)/kernel
1308 @rm -f $(MODLIB)/source
1309 @mkdir -p $(MODLIB)/kernel
1310 @ln -s $(abspath $(srctree)) $(MODLIB)/source
1311 @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
1312 rm -f $(MODLIB)/build ; \
1313 ln -s $(CURDIR) $(MODLIB)/build ; \
1315 @cp -f $(objtree)/modules.order $(MODLIB)/
1316 @cp -f $(objtree)/modules.builtin $(MODLIB)/
1317 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1319 # This depmod is only for convenience to give the initial
1320 # boot a modules.dep even before / is mounted read-write. However the
1321 # boot script depmod is the master version.
1322 PHONY += _modinst_post
1323 _modinst_post: _modinst_
1326 ifeq ($(CONFIG_MODULE_SIG), y)
1327 PHONY += modules_sign
1329 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1332 else # CONFIG_MODULES
1334 # Modules not configured
1335 # ---------------------------------------------------------------------------
1337 PHONY += modules modules_install
1338 modules modules_install:
1340 @echo >&2 "The present kernel configuration has modules disabled."
1341 @echo >&2 "Type 'make config' and enable loadable module support."
1342 @echo >&2 "Then build a kernel with module support enabled."
1346 endif # CONFIG_MODULES
1349 # Cleaning is done on three levels.
1350 # make clean Delete most generated files
1351 # Leave enough to build external modules
1352 # make mrproper Delete the current configuration, and all generated files
1353 # make distclean Remove editor backup files, patch leftover files and the like
1355 # Directories & files removed with 'make clean'
1356 CLEAN_DIRS += $(MODVERDIR) include/ksym
1358 # Directories & files removed with 'make mrproper'
1359 MRPROPER_DIRS += include/config usr/include include/generated \
1360 arch/*/include/generated .tmp_objdiff
1361 MRPROPER_FILES += .config .config.old .version \
1362 Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
1363 signing_key.pem signing_key.priv signing_key.x509 \
1364 x509.genkey extra_certificates signing_key.x509.keyid \
1365 signing_key.x509.signer vmlinux-gdb.py
1367 # clean - Delete most, but leave enough to build external modules
1369 clean: rm-dirs := $(CLEAN_DIRS)
1370 clean: rm-files := $(CLEAN_FILES)
1371 clean-dirs := $(addprefix _clean_, . $(vmlinux-alldirs) Documentation samples)
1373 PHONY += $(clean-dirs) clean archclean vmlinuxclean
1375 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1378 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1379 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1381 clean: archclean vmlinuxclean
1383 # mrproper - Delete all generated files, including .config
1385 mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS))
1386 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1387 mrproper-dirs := $(addprefix _mrproper_,scripts)
1389 PHONY += $(mrproper-dirs) mrproper archmrproper
1391 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1393 mrproper: clean archmrproper $(mrproper-dirs)
1402 @find $(srctree) $(RCS_FIND_IGNORE) \
1403 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1404 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1405 -o -name 'core' \) \
1406 -type f -print | xargs rm -f
1409 # Packaging of the kernel to various formats
1410 # ---------------------------------------------------------------------------
1411 # rpm target kept for backward compatibility
1412 package-dir := scripts/package
1415 $(Q)$(MAKE) $(build)=$(package-dir) $@
1416 %pkg: include/config/kernel.release FORCE
1417 $(Q)$(MAKE) $(build)=$(package-dir) $@
1419 @echo " WARNING: \"rpm\" target will be removed after Linux 4.18"
1420 @echo " Please use \"rpm-pkg\" instead."
1423 # Brief documentation of the typical targets used
1424 # ---------------------------------------------------------------------------
1426 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1427 boards := $(sort $(notdir $(boards)))
1428 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1429 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1433 @echo 'Cleaning targets:'
1434 @echo ' clean - Remove most generated files but keep the config and'
1435 @echo ' enough build support to build external modules'
1436 @echo ' mrproper - Remove all generated files + config + various backup files'
1437 @echo ' distclean - mrproper + remove editor backup and patch files'
1439 @echo 'Configuration targets:'
1440 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1442 @echo 'Other generic targets:'
1443 @echo ' all - Build all targets marked with [*]'
1444 @echo '* vmlinux - Build the bare kernel'
1445 @echo '* modules - Build all modules'
1446 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1447 @echo ' dir/ - Build all files in dir and below'
1448 @echo ' dir/file.[ois] - Build specified target only'
1449 @echo ' dir/file.ll - Build the LLVM assembly file'
1450 @echo ' (requires compiler support for LLVM assembly generation)'
1451 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1452 @echo ' (requires a recent binutils and recent build (System.map))'
1453 @echo ' dir/file.ko - Build module including final link'
1454 @echo ' modules_prepare - Set up for building external modules'
1455 @echo ' tags/TAGS - Generate tags file for editors'
1456 @echo ' cscope - Generate cscope index'
1457 @echo ' gtags - Generate GNU GLOBAL index'
1458 @echo ' kernelrelease - Output the release version string (use with make -s)'
1459 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1460 @echo ' image_name - Output the image name (use with make -s)'
1461 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1462 echo ' (default: $(INSTALL_HDR_PATH))'; \
1464 @echo 'Static analysers:'
1465 @echo ' checkstack - Generate a list of stack hogs'
1466 @echo ' namespacecheck - Name space analysis on compiled kernel'
1467 @echo ' versioncheck - Sanity check on version.h usage'
1468 @echo ' includecheck - Check for duplicate included header files'
1469 @echo ' export_report - List the usages of all exported symbols'
1470 @echo ' headers_check - Sanity check on exported headers'
1471 @echo ' headerdep - Detect inclusion cycles in headers'
1472 @echo ' coccicheck - Check with Coccinelle'
1474 @echo 'Kernel selftest:'
1475 @echo ' kselftest - Build and run kernel selftest (run as root)'
1476 @echo ' Build, install, and boot kernel before'
1477 @echo ' running kselftest on it'
1478 @echo ' kselftest-clean - Remove all generated kselftest files'
1479 @echo ' kselftest-merge - Merge all the config dependencies of kselftest to existing'
1482 @echo 'Userspace tools targets:'
1483 @echo ' use "make tools/help"'
1484 @echo ' or "cd tools; make help"'
1486 @echo 'Kernel packaging:'
1487 @$(MAKE) $(build)=$(package-dir) help
1489 @echo 'Documentation targets:'
1490 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1492 @echo 'Architecture specific targets ($(SRCARCH)):'
1493 @$(if $(archhelp),$(archhelp),\
1494 echo ' No architecture specific help defined for $(SRCARCH)')
1497 $(foreach b, $(boards), \
1498 printf " %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1500 @$(if $(board-dirs), \
1501 $(foreach b, $(board-dirs), \
1502 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1503 printf " %-16s - Show all of the above\\n" help-boards; \
1506 @echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1507 @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
1508 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1509 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK (sparse by default)'
1510 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1511 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1512 @echo ' make W=n [targets] Enable extra gcc checks, n=1,2,3 where'
1513 @echo ' 1: warnings which may be relevant and do not occur too often'
1514 @echo ' 2: warnings which occur quite often but may still be relevant'
1515 @echo ' 3: more obscure warnings, can most likely be ignored'
1516 @echo ' Multiple levels can be combined with W=12 or W=123'
1518 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1519 @echo 'For further info see the ./README file'
1522 help-board-dirs := $(addprefix help-,$(board-dirs))
1524 help-boards: $(help-board-dirs)
1526 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1528 $(help-board-dirs): help-%:
1529 @echo 'Architecture specific targets ($(SRCARCH) $*):'
1530 @$(if $(boards-per-dir), \
1531 $(foreach b, $(boards-per-dir), \
1532 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1536 # Documentation targets
1537 # ---------------------------------------------------------------------------
1538 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1539 linkcheckdocs dochelp refcheckdocs
1540 PHONY += $(DOC_TARGETS)
1541 $(DOC_TARGETS): scripts_basic FORCE
1542 $(Q)$(MAKE) $(build)=Documentation $@
1544 else # KBUILD_EXTMOD
1547 # External module support.
1548 # When building external modules the kernel used as basis is considered
1549 # read-only, and no consistency checks are made and the make
1550 # system is not used on the basis kernel. If updates are required
1551 # in the basis kernel ordinary make commands (without M=...) must
1554 # The following are the only valid targets when building external
1556 # make M=dir clean Delete all automatically generated files
1557 # make M=dir modules Make all modules in specified dir
1558 # make M=dir Same as 'make M=dir modules'
1559 # make M=dir modules_install
1560 # Install the modules built in the module directory
1561 # Assumes install directory is already created
1563 # We are always building modules
1565 PHONY += crmodverdir
1569 PHONY += $(objtree)/Module.symvers
1570 $(objtree)/Module.symvers:
1571 @test -e $(objtree)/Module.symvers || ( \
1573 echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1574 echo " is missing; modules will have no dependencies and modversions."; \
1577 module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
1578 PHONY += $(module-dirs) modules
1579 $(module-dirs): crmodverdir $(objtree)/Module.symvers
1580 $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
1582 modules: $(module-dirs)
1583 @$(kecho) ' Building modules, stage 2.';
1584 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1586 PHONY += modules_install
1587 modules_install: _emodinst_ _emodinst_post
1589 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1592 $(Q)mkdir -p $(MODLIB)/$(install-dir)
1593 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1595 PHONY += _emodinst_post
1596 _emodinst_post: _emodinst_
1599 clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))
1601 PHONY += $(clean-dirs) clean
1603 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1605 clean: rm-dirs := $(MODVERDIR)
1606 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1610 @echo ' Building external modules.'
1611 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1613 @echo ' modules - default target, build the module(s)'
1614 @echo ' modules_install - install the module'
1615 @echo ' clean - remove generated files in module directory only'
1619 PHONY += prepare scripts
1622 endif # KBUILD_EXTMOD
1624 clean: $(clean-dirs)
1627 @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1628 \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1629 -o -name '*.ko.*' -o -name '*.dtb' -o -name '*.dtb.S' \
1630 -o -name '*.dwo' -o -name '*.lst' \
1632 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1633 -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1634 -o -name '*.asn1.[ch]' \
1635 -o -name '*.symtypes' -o -name 'modules.order' \
1636 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1637 -o -name '*.c.[012]*.*' \
1639 -o -name '*.gcno' \) -type f -print | xargs rm -f
1641 # Generate tags for editors
1642 # ---------------------------------------------------------------------------
1643 quiet_cmd_tags = GEN $@
1644 cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
1646 tags TAGS cscope gtags: FORCE
1649 # Scripts to check various things for consistency
1650 # ---------------------------------------------------------------------------
1652 PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1655 find $(srctree)/* $(RCS_FIND_IGNORE) \
1656 -name '*.[hcS]' -type f -print | sort \
1657 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1660 find $(srctree)/* $(RCS_FIND_IGNORE) \
1661 -name '*.[hcS]' -type f -print | sort \
1662 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1665 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1668 $(PERL) $(srctree)/scripts/namespace.pl
1671 $(PERL) $(srctree)/scripts/export_report.pl
1673 endif #ifeq ($(config-targets),1)
1674 endif #ifeq ($(mixed-targets),1)
1676 PHONY += checkstack kernelrelease kernelversion image_name
1678 # UML needs a little special treatment here. It wants to use the host
1679 # toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
1680 # else wants $(ARCH), including people doing cross-builds, which means
1681 # that $(SUBARCH) doesn't work here.
1683 CHECKSTACK_ARCH := $(SUBARCH)
1685 CHECKSTACK_ARCH := $(ARCH)
1688 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1689 $(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1692 @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1695 @echo $(KERNELVERSION)
1698 @echo $(KBUILD_IMAGE)
1700 # Clear a bunch of variables before executing the submake
1702 $(Q)mkdir -p $(objtree)/tools
1703 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/
1706 $(Q)mkdir -p $(objtree)/tools
1707 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/ $*
1710 # ---------------------------------------------------------------------------
1711 # Single targets are compatible with:
1712 # - build with mixed source and output
1713 # - build with separate output dir 'make O=...'
1714 # - external modules
1716 # target-dir => where to store outputfile
1717 # build-dir => directory in kernel source tree to use
1719 ifeq ($(KBUILD_EXTMOD),)
1720 build-dir = $(patsubst %/,%,$(dir $@))
1721 target-dir = $(dir $@)
1723 zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
1724 build-dir = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
1725 target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@))
1728 %.s: %.c prepare scripts FORCE
1729 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1730 %.i: %.c prepare scripts FORCE
1731 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1732 %.o: %.c prepare scripts FORCE
1733 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1734 %.lst: %.c prepare scripts FORCE
1735 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1736 %.s: %.S prepare scripts FORCE
1737 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1738 %.o: %.S prepare scripts FORCE
1739 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1740 %.symtypes: %.c prepare scripts FORCE
1741 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1742 %.ll: %.c prepare scripts FORCE
1743 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1746 /: prepare scripts FORCE
1748 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1749 $(build)=$(build-dir)
1750 # Make sure the latest headers are built for Documentation
1751 Documentation/ samples/: headers_install
1752 %/: prepare scripts FORCE
1754 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1755 $(build)=$(build-dir)
1756 %.ko: prepare scripts FORCE
1758 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1759 $(build)=$(build-dir) $(@:.ko=.o)
1760 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1762 # FIXME Should go into a make.lib or something
1763 # ===========================================================================
1765 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs)))
1766 cmd_rmdirs = rm -rf $(rm-dirs)
1768 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
1769 cmd_rmfiles = rm -f $(rm-files)
1771 # Run depmod only if we have System.map and depmod is executable
1772 quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
1773 cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1776 # Create temporary dir for module support files
1777 # clean it up only when building all modules
1778 cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
1779 $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
1781 # read all saved command lines
1783 cmd_files := $(wildcard .*.cmd $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd))
1785 ifneq ($(cmd_files),)
1786 $(cmd_files): ; # Do not try to update included dependency files
1787 include $(cmd_files)
1790 endif # skip-makefile
1795 # Declare the contents of the .PHONY variable as phony. We keep that
1796 # information in a variable so we can use it in if_changed and friends.