8 # To see a list of typical targets execute "make help"
9 # More info can be located in ./README
10 # Comments in this file are targeted only to the developer, do not
11 # expect to learn how to build the kernel reading this file.
13 # o Do not use make's built-in rules and variables
14 # (this increases performance and avoids hard-to-debug behaviour);
15 # o Look for make include files relative to root of kernel src
16 MAKEFLAGS += -rR --include-dir=$(CURDIR)
18 # Avoid funny character set dependencies
22 export LC_COLLATE LC_NUMERIC
24 # Avoid interference with shell env settings
27 # We are using a recursive build, so we need to do a little thinking
28 # to get the ordering right.
30 # Most importantly: sub-Makefiles should only ever modify files in
31 # their own directory. If in some directory we have a dependency on
32 # a file in another dir (which doesn't happen often, but it's often
33 # unavoidable when linking the built-in.o targets which finally
34 # turn into vmlinux), we will call a sub make in that other dir, and
35 # after that we are sure that everything which is in that other dir
38 # The only cases where we need to modify files which have global
39 # effects are thus separated out and done before the recursive
40 # descending is started. They are now explicitly listed as the
44 # ---------------------------------------------------------------------------
46 # Normally, we echo the whole command before executing it. By making
47 # that echo $($(quiet)$(cmd)), we now have the possibility to set
48 # $(quiet) to choose other forms of output instead, e.g.
50 # quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
51 # cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
53 # If $(quiet) is empty, the whole command will be printed.
54 # If it is set to "quiet_", only the short version will be printed.
55 # If it is set to "silent_", nothing will be printed at all, since
56 # the variable $(silent_cmd_cc_o_c) doesn't exist.
58 # A simple variant is to prefix commands with $(Q) - that's useful
59 # for commands that shall be hidden in non-verbose mode.
63 # If KBUILD_VERBOSE equals 0 then the above command will be hidden.
64 # If KBUILD_VERBOSE equals 1 then the above command is displayed.
66 # To put more focus on warnings, be less verbose as default
67 # Use 'make V=1' to see the full commands
69 ifeq ("$(origin V)", "command line")
76 ifeq ($(KBUILD_VERBOSE),1)
84 # If the user is running make -s (silent mode), suppress echoing of
87 ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
92 export quiet Q KBUILD_VERBOSE
94 # kbuild supports saving output files in a separate directory.
95 # To locate output files in a separate directory two syntaxes are supported.
96 # In both cases the working directory must be the root of the kernel src.
98 # Use "make O=dir/to/store/output/files/"
100 # 2) Set KBUILD_OUTPUT
101 # Set the environment variable KBUILD_OUTPUT to point to the directory
102 # where the output files shall be placed.
103 # export KBUILD_OUTPUT=dir/to/store/output/files/
106 # The O= assignment takes precedence over the KBUILD_OUTPUT environment
109 # KBUILD_SRC is not intended to be used by the regular user (for now),
110 # it is set on invocation of make with KBUILD_OUTPUT or O= specified.
111 ifeq ($(KBUILD_SRC),)
113 # OK, Make called in directory where kernel src resides
114 # Do we want to locate output files in a separate directory?
115 ifeq ("$(origin O)", "command line")
116 KBUILD_OUTPUT := $(O)
119 # That's our default target when none is given on the command line
123 # Cancel implicit rules on top Makefile
124 $(CURDIR)/Makefile Makefile: ;
126 ifneq ($(words $(subst :, ,$(CURDIR))), 1)
127 $(error main directory cannot contain spaces nor colons)
130 ifneq ($(KBUILD_OUTPUT),)
131 # check that the output directory actually exists
132 saved-output := $(KBUILD_OUTPUT)
133 KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
135 $(if $(KBUILD_OUTPUT),, \
136 $(error failed to create output directory "$(saved-output)"))
138 PHONY += $(MAKECMDGOALS) sub-make
140 $(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
143 # Invoke a second make in the output directory, passing relevant variables
145 $(Q)$(MAKE) -C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR) \
146 -f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS))
148 # Leave processing to above invocation of make
150 endif # ifneq ($(KBUILD_OUTPUT),)
151 endif # ifeq ($(KBUILD_SRC),)
153 # We process the rest of the Makefile if this is the final invocation of make
154 ifeq ($(skip-makefile),)
156 # Do not print "Entering directory ...",
157 # but we want to display it when entering to the output directory
158 # so that IDEs/editors are able to understand relative filenames.
159 MAKEFLAGS += --no-print-directory
161 # Call a source code checker (by default, "sparse") as part of the
164 # Use 'make C=1' to enable checking of only re-compiled files.
165 # Use 'make C=2' to enable checking of *all* source files, regardless
166 # of whether they are re-compiled or not.
168 # See the file "Documentation/dev-tools/sparse.rst" for more details,
169 # including where to get the "sparse" utility.
171 ifeq ("$(origin C)", "command line")
172 KBUILD_CHECKSRC = $(C)
174 ifndef KBUILD_CHECKSRC
178 # Use make M=dir to specify directory of external module to build
179 # Old syntax make ... SUBDIRS=$PWD is still supported
180 # Setting the environment variable KBUILD_EXTMOD take precedence
182 KBUILD_EXTMOD ?= $(SUBDIRS)
185 ifeq ("$(origin M)", "command line")
186 KBUILD_EXTMOD := $(M)
189 # If building an external module we do not care about the all: rule
190 # but instead _all depend on modules
192 ifeq ($(KBUILD_EXTMOD),)
198 ifeq ($(KBUILD_SRC),)
199 # building in the source tree
202 ifeq ($(KBUILD_SRC)/,$(dir $(CURDIR)))
203 # building in a subdirectory of the source tree
206 srctree := $(KBUILD_SRC)
213 VPATH := $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))
215 export srctree objtree VPATH
217 # SUBARCH tells the usermode build what the underlying arch is. That is set
218 # first, and if a usermode build is happening, the "ARCH=um" on the command
219 # line overrides the setting of ARCH below. If a native build is happening,
220 # then ARCH is assigned, getting whatever value it gets normally, and
221 # SUBARCH is subsequently ignored.
223 SUBARCH := $(shell uname -m | sed -e s/i.86/x86/ -e s/x86_64/x86/ \
224 -e s/sun4u/sparc64/ \
225 -e s/arm.*/arm/ -e s/sa110/arm/ \
226 -e s/s390x/s390/ -e s/parisc64/parisc/ \
227 -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
228 -e s/sh[234].*/sh/ -e s/aarch64.*/arm64/ )
230 # Cross compiling and selecting different set of gcc/bin-utils
231 # ---------------------------------------------------------------------------
233 # When performing cross compilation for other architectures ARCH shall be set
234 # to the target architecture. (See arch/* for the possibilities).
235 # ARCH can be set during invocation of make:
237 # Another way is to have ARCH set in the environment.
238 # The default ARCH is the host where make is executed.
240 # CROSS_COMPILE specify the prefix used for all executables used
241 # during compilation. Only gcc and related bin-utils executables
242 # are prefixed with $(CROSS_COMPILE).
243 # CROSS_COMPILE can be set on the command line
244 # make CROSS_COMPILE=ia64-linux-
245 # Alternatively CROSS_COMPILE can be set in the environment.
246 # A third alternative is to store a setting in .config so that plain
247 # "make" in the configured kernel build directory always uses that.
248 # Default value for CROSS_COMPILE is not to prefix executables
249 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
251 CROSS_COMPILE ?= $(CONFIG_CROSS_COMPILE:"%"=%)
253 # Architecture as present in compile.h
254 UTS_MACHINE := $(ARCH)
257 # Additional ARCH settings for x86
261 ifeq ($(ARCH),x86_64)
265 # Additional ARCH settings for sparc
266 ifeq ($(ARCH),sparc32)
269 ifeq ($(ARCH),sparc64)
273 # Additional ARCH settings for sh
278 # Additional ARCH settings for tile
279 ifeq ($(ARCH),tilepro)
282 ifeq ($(ARCH),tilegx)
286 # Where to locate arch specific headers
287 hdr-arch := $(SRCARCH)
289 KCONFIG_CONFIG ?= .config
290 export KCONFIG_CONFIG
292 # SHELL used by kbuild
293 CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
294 else if [ -x /bin/bash ]; then echo /bin/bash; \
295 else echo sh; fi ; fi)
299 HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer -std=gnu89
302 ifeq ($(shell $(HOSTCC) -v 2>&1 | grep -c "clang version"), 1)
303 HOSTCFLAGS += -Wno-unused-value -Wno-unused-parameter \
304 -Wno-missing-field-initializers -fno-delete-null-pointer-checks
307 # Decide whether to build built-in, modular, or both.
308 # Normally, just do built-in.
313 # If we have only "make modules", don't compile built-in objects.
314 # When we're building modules with modversions, we need to consider
315 # the built-in objects during the descend as well, in order to
316 # make sure the checksums are up to date before we record them.
318 ifeq ($(MAKECMDGOALS),modules)
319 KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
322 # If we have "make <whatever> modules", compile modules
323 # in addition to whatever we do anyway.
324 # Just "make" or "make all" shall build modules as well
326 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
330 ifeq ($(MAKECMDGOALS),)
334 export KBUILD_MODULES KBUILD_BUILTIN
335 export KBUILD_CHECKSRC KBUILD_SRC KBUILD_EXTMOD
337 # We need some generic definitions (do not try to remake the file).
338 scripts/Kbuild.include: ;
339 include scripts/Kbuild.include
341 # Make variables (CC, etc...)
342 AS = $(CROSS_COMPILE)as
343 LD = $(CROSS_COMPILE)ld
344 CC = $(CROSS_COMPILE)gcc
346 AR = $(CROSS_COMPILE)ar
347 NM = $(CROSS_COMPILE)nm
348 STRIP = $(CROSS_COMPILE)strip
349 OBJCOPY = $(CROSS_COMPILE)objcopy
350 OBJDUMP = $(CROSS_COMPILE)objdump
352 GENKSYMS = scripts/genksyms/genksyms
353 INSTALLKERNEL := installkernel
354 DEPMOD = /sbin/depmod
359 CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
360 -Wbitwise -Wno-return-void $(CF)
368 CFLAGS_GCOV := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,)
369 CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,)
372 # Use USERINCLUDE when you must reference the UAPI directories only.
374 -I$(srctree)/arch/$(hdr-arch)/include/uapi \
375 -I$(objtree)/arch/$(hdr-arch)/include/generated/uapi \
376 -I$(srctree)/include/uapi \
377 -I$(objtree)/include/generated/uapi \
378 -include $(srctree)/include/linux/kconfig.h
380 # Use LINUXINCLUDE when you must reference the include/ directory.
381 # Needed to be compatible with the O= option
383 -I$(srctree)/arch/$(hdr-arch)/include \
384 -I$(objtree)/arch/$(hdr-arch)/include/generated \
385 $(if $(KBUILD_SRC), -I$(srctree)/include) \
386 -I$(objtree)/include \
389 KBUILD_CPPFLAGS := -D__KERNEL__
391 KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
392 -fno-strict-aliasing -fno-common \
393 -Werror-implicit-function-declaration \
394 -Wno-format-security \
395 -std=gnu89 $(call cc-option,-fno-PIE)
398 KBUILD_AFLAGS_KERNEL :=
399 KBUILD_CFLAGS_KERNEL :=
400 KBUILD_AFLAGS := -D__ASSEMBLY__ $(call cc-option,-fno-PIE)
401 KBUILD_AFLAGS_MODULE := -DMODULE
402 KBUILD_CFLAGS_MODULE := -DMODULE
403 KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
405 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
406 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
407 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
409 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
410 export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC
411 export CPP AR NM STRIP OBJCOPY OBJDUMP
412 export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE
413 export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
415 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
416 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_GCOV CFLAGS_KCOV CFLAGS_KASAN CFLAGS_UBSAN
417 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
418 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
419 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
420 export KBUILD_ARFLAGS
422 # When compiling out-of-tree modules, put MODVERDIR in the module
423 # tree rather than in the kernel tree. The kernel tree might
425 export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
427 # Files to ignore in find ... statements
429 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
430 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
432 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
433 --exclude CVS --exclude .pc --exclude .hg --exclude .git
435 # ===========================================================================
436 # Rules shared between *config targets and build targets
438 # Basic helpers built in scripts/
439 PHONY += scripts_basic
441 $(Q)$(MAKE) $(build)=scripts/basic
442 $(Q)rm -f .tmp_quiet_recordmcount
444 # To avoid any implicit rule to kick in, define an empty command.
445 scripts/basic/%: scripts_basic ;
447 PHONY += outputmakefile
448 # outputmakefile generates a Makefile in the output directory, if using a
449 # separate output directory. This allows convenient use of make in the
452 ifneq ($(KBUILD_SRC),)
453 $(Q)ln -fsn $(srctree) source
454 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile \
455 $(srctree) $(objtree) $(VERSION) $(PATCHLEVEL)
458 # Support for using generic headers in asm-generic
461 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
462 src=asm obj=arch/$(SRCARCH)/include/generated/asm
463 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
464 src=uapi/asm obj=arch/$(SRCARCH)/include/generated/uapi/asm
466 # To make sure we do not include .config for any of the *config targets
467 # catch them early, and hand them over to scripts/kconfig/Makefile
468 # It is allowed to specify more targets when calling make, including
469 # mixing *config targets and build targets.
470 # For example 'make oldconfig all'.
471 # Detect when mixed targets is specified, and make a second invocation
472 # of make so .config is not included in this case either (for *config).
474 version_h := include/generated/uapi/linux/version.h
475 old_version_h := include/linux/version.h
477 no-dot-config-targets := clean mrproper distclean \
478 cscope gtags TAGS tags help% %docs check% coccicheck \
479 $(version_h) headers_% archheaders archscripts \
480 kernelversion %src-pkg
486 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
487 ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
492 ifeq ($(KBUILD_EXTMOD),)
493 ifneq ($(filter config %config,$(MAKECMDGOALS)),)
495 ifneq ($(words $(MAKECMDGOALS)),1)
500 # install and module_install need also be processed one by one
501 ifneq ($(filter install,$(MAKECMDGOALS)),)
502 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
507 ifeq ($(mixed-targets),1)
508 # ===========================================================================
509 # We're called with mixed targets (*config and build targets).
510 # Handle them one by one.
512 PHONY += $(MAKECMDGOALS) __build_one_by_one
514 $(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
519 for i in $(MAKECMDGOALS); do \
520 $(MAKE) -f $(srctree)/Makefile $$i; \
524 ifeq ($(config-targets),1)
525 # ===========================================================================
526 # *config targets only - make sure prerequisites are updated, and descend
527 # in scripts/kconfig to make the *config target
529 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
530 # KBUILD_DEFCONFIG may point out an alternative default configuration
531 # used for 'make defconfig'
532 include arch/$(SRCARCH)/Makefile
533 export KBUILD_DEFCONFIG KBUILD_KCONFIG
535 config: scripts_basic outputmakefile FORCE
536 $(Q)$(MAKE) $(build)=scripts/kconfig $@
538 %config: scripts_basic outputmakefile FORCE
539 $(Q)$(MAKE) $(build)=scripts/kconfig $@
542 # ===========================================================================
543 # Build targets only - this includes vmlinux, arch specific targets, clean
544 # targets and others. In general all targets except *config targets.
546 ifeq ($(KBUILD_EXTMOD),)
547 # Additional helpers built in scripts/
548 # Carefully list dependencies so we do not try to build scripts twice
551 scripts: scripts_basic include/config/auto.conf include/config/tristate.conf \
552 asm-generic gcc-plugins
553 $(Q)$(MAKE) $(build)=$(@)
555 # Objects we will link into vmlinux / subdirs we need to visit
557 drivers-y := drivers/ sound/ firmware/
562 endif # KBUILD_EXTMOD
564 ifeq ($(dot-config),1)
566 -include include/config/auto.conf
568 ifeq ($(KBUILD_EXTMOD),)
569 # Read in dependencies to all Kconfig* files, make sure to run
570 # oldconfig if changes are detected.
571 -include include/config/auto.conf.cmd
573 # To avoid any implicit rule to kick in, define an empty command
574 $(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;
576 # If .config is newer than include/config/auto.conf, someone tinkered
577 # with it and forgot to run make oldconfig.
578 # if auto.conf.cmd is missing then we are probably in a cleaned tree so
579 # we execute the config step to be sure to catch updated Kconfig files
580 include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
581 $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig
583 # external modules needs include/generated/autoconf.h and include/config/auto.conf
584 # but do not care if they are up-to-date. Use auto.conf to trigger the test
585 PHONY += include/config/auto.conf
587 include/config/auto.conf:
588 $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
590 echo >&2 " ERROR: Kernel configuration is invalid."; \
591 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
592 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
596 endif # KBUILD_EXTMOD
599 # Dummy target needed, because used as prerequisite
600 include/config/auto.conf: ;
601 endif # $(dot-config)
603 # For the kernel to actually contain only the needed exported symbols,
604 # we have to build modules as well to determine what those symbols are.
605 # (this can be evaluated only once include/config/auto.conf has been included)
606 ifdef CONFIG_TRIM_UNUSED_KSYMS
610 # The all: target is the default when no target is given on the
612 # This allow a user to issue only 'make' to build a kernel including modules
613 # Defaults to vmlinux, but the arch makefile usually adds further targets
616 # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
617 # values of the respective KBUILD_* variables
621 include arch/$(SRCARCH)/Makefile
623 KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
624 KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
626 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
627 KBUILD_CFLAGS += $(call cc-option,-Oz,-Os)
628 KBUILD_CFLAGS += $(call cc-disable-warning,maybe-uninitialized,)
630 ifdef CONFIG_PROFILE_ALL_BRANCHES
631 KBUILD_CFLAGS += -O2 $(call cc-disable-warning,maybe-uninitialized,)
637 KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \
638 $(call cc-disable-warning,maybe-uninitialized,))
640 # Tell gcc to never replace conditional load with a non-conditional one
641 KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
643 # check for 'asm goto'
644 ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y)
645 KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
646 KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO
649 include scripts/Makefile.gcc-plugins
651 ifdef CONFIG_READABLE_ASM
652 # Disable optimizations that make assembler listings hard to read.
653 # reorder blocks reorders the control in the function
654 # ipa clone creates specialized cloned functions
655 # partial inlining inlines only parts of functions
656 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
657 $(call cc-option,-fno-ipa-cp-clone,) \
658 $(call cc-option,-fno-partial-inlining)
661 ifneq ($(CONFIG_FRAME_WARN),0)
662 KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
665 # This selects the stack protector compiler flag. Testing it is delayed
666 # until after .config has been reprocessed, in the prepare-compiler-check
668 ifdef CONFIG_CC_STACKPROTECTOR_REGULAR
669 stackp-flag := -fstack-protector
670 stackp-name := REGULAR
672 ifdef CONFIG_CC_STACKPROTECTOR_STRONG
673 stackp-flag := -fstack-protector-strong
674 stackp-name := STRONG
676 # Force off for distro compilers that enable stack protector by default.
677 stackp-flag := $(call cc-option, -fno-stack-protector)
680 # Find arch-specific stack protector compiler sanity-checking script.
681 ifdef CONFIG_CC_STACKPROTECTOR
682 stackp-path := $(srctree)/scripts/gcc-$(SRCARCH)_$(BITS)-has-stack-protector.sh
683 stackp-check := $(wildcard $(stackp-path))
685 KBUILD_CFLAGS += $(stackp-flag)
687 ifeq ($(cc-name),clang)
688 ifneq ($(CROSS_COMPILE),)
689 CLANG_TARGET := -target $(notdir $(CROSS_COMPILE:%-=%))
690 GCC_TOOLCHAIN := $(realpath $(dir $(shell which $(LD)))/..)
692 ifneq ($(GCC_TOOLCHAIN),)
693 CLANG_GCC_TC := -gcc-toolchain $(GCC_TOOLCHAIN)
695 KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
696 KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
697 KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
698 KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable)
699 KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
700 KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
701 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
702 # Quiet clang warning: comparison of unsigned expression < 0 is always false
703 KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
704 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
705 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
706 # See modpost pattern 2
707 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
708 KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
709 KBUILD_CFLAGS += $(call cc-option, -no-integrated-as)
710 KBUILD_AFLAGS += $(call cc-option, -no-integrated-as)
713 # These warnings generated too much noise in a regular build.
714 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
715 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
716 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
719 ifdef CONFIG_FRAME_POINTER
720 KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
722 # Some targets (ARM with Thumb2, for example), can't be built with frame
723 # pointers. For those, we don't have FUNCTION_TRACER automatically
724 # select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
725 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
726 # -fomit-frame-pointer with FUNCTION_TRACER.
727 ifndef CONFIG_FUNCTION_TRACER
728 KBUILD_CFLAGS += -fomit-frame-pointer
732 KBUILD_CFLAGS += $(call cc-option, -fno-var-tracking-assignments)
734 ifdef CONFIG_DEBUG_INFO
735 ifdef CONFIG_DEBUG_INFO_SPLIT
736 KBUILD_CFLAGS += $(call cc-option, -gsplit-dwarf, -g)
740 KBUILD_AFLAGS += -Wa,-gdwarf-2
742 ifdef CONFIG_DEBUG_INFO_DWARF4
743 KBUILD_CFLAGS += $(call cc-option, -gdwarf-4,)
746 ifdef CONFIG_DEBUG_INFO_REDUCED
747 KBUILD_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
748 $(call cc-option,-fno-var-tracking)
751 ifdef CONFIG_FUNCTION_TRACER
752 ifndef CC_FLAGS_FTRACE
753 CC_FLAGS_FTRACE := -pg
755 export CC_FLAGS_FTRACE
756 ifdef CONFIG_HAVE_FENTRY
757 CC_USING_FENTRY := $(call cc-option, -mfentry -DCC_USING_FENTRY)
759 KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_USING_FENTRY)
760 KBUILD_AFLAGS += $(CC_USING_FENTRY)
761 ifdef CONFIG_DYNAMIC_FTRACE
762 ifdef CONFIG_HAVE_C_RECORDMCOUNT
763 BUILD_C_RECORDMCOUNT := y
764 export BUILD_C_RECORDMCOUNT
769 # We trigger additional mismatches with less inlining
770 ifdef CONFIG_DEBUG_SECTION_MISMATCH
771 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
774 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
775 KBUILD_CFLAGS += $(call cc-option,-ffunction-sections,)
776 KBUILD_CFLAGS += $(call cc-option,-fdata-sections,)
779 # arch Makefile may override CC so keep this after arch Makefile is included
780 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
781 CHECKFLAGS += $(NOSTDINC_FLAGS)
783 # warn about C99 declaration after statement
784 KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
786 # disable pointer signed / unsigned warnings in gcc 4.0
787 KBUILD_CFLAGS += $(call cc-disable-warning, pointer-sign)
789 # disable invalid "can't wrap" optimizations for signed / pointers
790 KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
792 # conserve stack if available
793 KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
795 # disallow errors like 'EXPORT_GPL(foo);' with missing header
796 KBUILD_CFLAGS += $(call cc-option,-Werror=implicit-int)
798 # require functions to have arguments in prototypes, not empty 'int foo()'
799 KBUILD_CFLAGS += $(call cc-option,-Werror=strict-prototypes)
801 # Prohibit date/time macros, which would make the build non-deterministic
802 KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
804 # enforce correct pointer usage
805 KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
807 # Require designated initializers for all marked structures
808 KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
810 # use the deterministic mode of AR if available
811 KBUILD_ARFLAGS := $(call ar-option,D)
813 include scripts/Makefile.kasan
814 include scripts/Makefile.extrawarn
815 include scripts/Makefile.ubsan
817 # Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
819 KBUILD_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS)
820 KBUILD_AFLAGS += $(ARCH_AFLAGS) $(KAFLAGS)
821 KBUILD_CFLAGS += $(ARCH_CFLAGS) $(KCFLAGS)
823 # Use --build-id when available.
824 LDFLAGS_BUILD_ID := $(patsubst -Wl$(comma)%,%,\
825 $(call cc-ldoption, -Wl$(comma)--build-id,))
826 KBUILD_LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
827 LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
829 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
830 LDFLAGS_vmlinux += $(call ld-option, --gc-sections,)
833 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
834 LDFLAGS_vmlinux += $(call ld-option, -X,)
837 # Default kernel image to build when no specific target is given.
838 # KBUILD_IMAGE may be overruled on the command line or
839 # set in the environment
840 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
842 export KBUILD_IMAGE ?= vmlinux
845 # INSTALL_PATH specifies where to place the updated kernel and system map
846 # images. Default is /boot, but you can set it to other values
847 export INSTALL_PATH ?= /boot
850 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
851 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
852 # an argument if needed. Otherwise it defaults to the kernel install path
854 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
857 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
858 # relocations required by build roots. This is not defined in the
859 # makefile but the argument can be passed to make if needed.
862 MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
866 # INSTALL_MOD_STRIP, if defined, will cause modules to be
867 # stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
868 # the default option --strip-debug will be used. Otherwise,
869 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
871 ifdef INSTALL_MOD_STRIP
872 ifeq ($(INSTALL_MOD_STRIP),1)
873 mod_strip_cmd = $(STRIP) --strip-debug
875 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
876 endif # INSTALL_MOD_STRIP=1
879 endif # INSTALL_MOD_STRIP
882 # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
883 # after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
884 # or CONFIG_MODULE_COMPRESS_XZ.
886 mod_compress_cmd = true
887 ifdef CONFIG_MODULE_COMPRESS
888 ifdef CONFIG_MODULE_COMPRESS_GZIP
889 mod_compress_cmd = gzip -n -f
890 endif # CONFIG_MODULE_COMPRESS_GZIP
891 ifdef CONFIG_MODULE_COMPRESS_XZ
892 mod_compress_cmd = xz -f
893 endif # CONFIG_MODULE_COMPRESS_XZ
894 endif # CONFIG_MODULE_COMPRESS
895 export mod_compress_cmd
897 # Select initial ramdisk compression format, default is gzip(1).
898 # This shall be used by the dracut(8) tool while creating an initramfs image.
900 INITRD_COMPRESS-y := gzip
901 INITRD_COMPRESS-$(CONFIG_RD_BZIP2) := bzip2
902 INITRD_COMPRESS-$(CONFIG_RD_LZMA) := lzma
903 INITRD_COMPRESS-$(CONFIG_RD_XZ) := xz
904 INITRD_COMPRESS-$(CONFIG_RD_LZO) := lzo
905 INITRD_COMPRESS-$(CONFIG_RD_LZ4) := lz4
906 # do not export INITRD_COMPRESS, since we didn't actually
907 # choose a sane default compression above.
908 # export INITRD_COMPRESS := $(INITRD_COMPRESS-y)
910 ifdef CONFIG_MODULE_SIG_ALL
911 $(eval $(call config_filename,MODULE_SIG_KEY))
913 mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
919 ifdef CONFIG_STACK_VALIDATION
920 has_libelf := $(call try-run,\
921 echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0)
922 ifeq ($(has_libelf),1)
923 objtool_target := tools/objtool FORCE
925 $(warning "Cannot use CONFIG_STACK_VALIDATION, please install libelf-dev, libelf-devel or elfutils-libelf-devel")
926 SKIP_STACK_VALIDATION := 1
927 export SKIP_STACK_VALIDATION
932 ifeq ($(KBUILD_EXTMOD),)
933 core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
935 vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
936 $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
937 $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
939 vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
940 $(init-) $(core-) $(drivers-) $(net-) $(libs-) $(virt-))))
942 init-y := $(patsubst %/, %/built-in.o, $(init-y))
943 core-y := $(patsubst %/, %/built-in.o, $(core-y))
944 drivers-y := $(patsubst %/, %/built-in.o, $(drivers-y))
945 net-y := $(patsubst %/, %/built-in.o, $(net-y))
946 libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
947 libs-y2 := $(filter-out %.a, $(patsubst %/, %/built-in.o, $(libs-y)))
948 virt-y := $(patsubst %/, %/built-in.o, $(virt-y))
950 # Externally visible symbols (used by link-vmlinux.sh)
951 export KBUILD_VMLINUX_INIT := $(head-y) $(init-y)
952 export KBUILD_VMLINUX_MAIN := $(core-y) $(libs-y2) $(drivers-y) $(net-y) $(virt-y)
953 export KBUILD_VMLINUX_LIBS := $(libs-y1)
954 export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
955 export LDFLAGS_vmlinux
956 # used by scripts/pacmage/Makefile
957 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools)
959 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_INIT) $(KBUILD_VMLINUX_MAIN) $(KBUILD_VMLINUX_LIBS)
961 # Include targets which we want to execute sequentially if the rest of the
962 # kernel build went well. If CONFIG_TRIM_UNUSED_KSYMS is set, this might be
963 # evaluated more than once.
964 PHONY += vmlinux_prereq
965 vmlinux_prereq: $(vmlinux-deps) FORCE
966 ifdef CONFIG_HEADERS_CHECK
967 $(Q)$(MAKE) -f $(srctree)/Makefile headers_check
969 ifdef CONFIG_GDB_SCRIPTS
970 $(Q)ln -fsn `cd $(srctree) && /bin/pwd`/scripts/gdb/vmlinux-gdb.py
972 ifdef CONFIG_TRIM_UNUSED_KSYMS
973 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
974 "$(MAKE) -f $(srctree)/Makefile vmlinux"
977 # standalone target for easier testing
978 include/generated/autoksyms.h: FORCE
979 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh true
981 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
983 # Final link of vmlinux with optional arch pass after final link
985 $(CONFIG_SHELL) $< $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) ; \
986 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
988 vmlinux: scripts/link-vmlinux.sh vmlinux_prereq $(vmlinux-deps) FORCE
989 +$(call if_changed,link-vmlinux)
991 # Build samples along the rest of the kernel
993 vmlinux-dirs += samples
996 # The actual objects are generated when descending,
997 # make sure no implicit rule kicks in
998 $(sort $(vmlinux-deps)): $(vmlinux-dirs) ;
1000 # Handle descending into subdirectories listed in $(vmlinux-dirs)
1001 # Preset locale variables to speed up the build process. Limit locale
1002 # tweaks to this spot to avoid wrong language settings when running
1003 # make menuconfig etc.
1004 # Error messages still appears in the original language
1006 PHONY += $(vmlinux-dirs)
1007 $(vmlinux-dirs): prepare scripts
1008 $(Q)$(MAKE) $(build)=$@
1010 define filechk_kernel.release
1011 echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1014 # Store (new) KERNELRELEASE string in include/config/kernel.release
1015 include/config/kernel.release: include/config/auto.conf FORCE
1016 $(call filechk,kernel.release)
1019 # Things we need to do before we recursively start building the kernel
1020 # or the modules are listed in "prepare".
1021 # A multi level approach is used. prepareN is processed before prepareN-1.
1022 # archprepare is used in arch Makefiles and when processed asm symlink,
1023 # version.h and scripts_basic is processed / created.
1025 # Listed in dependency order
1026 PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3
1028 # prepare3 is used to check if we are building in a separate output directory,
1030 # 1) Check that make has not been executed in the kernel src $(srctree)
1031 prepare3: include/config/kernel.release
1032 ifneq ($(KBUILD_SRC),)
1033 @$(kecho) ' Using $(srctree) as source for kernel'
1034 $(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
1035 echo >&2 " $(srctree) is not clean, please run 'make mrproper'"; \
1036 echo >&2 " in the '$(srctree)' directory.";\
1041 # prepare2 creates a makefile if using a separate output directory.
1042 # From this point forward, .config has been reprocessed, so any rules
1043 # that need to depend on updated CONFIG_* values can be checked here.
1044 prepare2: prepare3 prepare-compiler-check outputmakefile asm-generic
1046 prepare1: prepare2 $(version_h) include/generated/utsrelease.h \
1047 include/config/auto.conf
1050 archprepare: archheaders archscripts prepare1 scripts_basic
1052 prepare0: archprepare gcc-plugins
1053 $(Q)$(MAKE) $(build)=.
1055 # All the preparing..
1056 prepare: prepare0 prepare-objtool
1058 PHONY += prepare-objtool
1059 prepare-objtool: $(objtool_target)
1061 # Check for CONFIG flags that require compiler support. Abort the build
1062 # after .config has been processed, but before the kernel build starts.
1064 # For security-sensitive CONFIG options, we don't want to fallback and/or
1065 # silently change which compiler flags will be used, since that leads to
1066 # producing kernels with different security feature characteristics
1067 # depending on the compiler used. (For example, "But I selected
1068 # CC_STACKPROTECTOR_STRONG! Why did it build with _REGULAR?!")
1069 PHONY += prepare-compiler-check
1070 prepare-compiler-check: FORCE
1071 # Make sure compiler supports requested stack protector flag.
1073 ifeq ($(call cc-option, $(stackp-flag)),)
1074 @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1075 $(stackp-flag) not supported by compiler >&2 && exit 1
1078 # Make sure compiler does not have buggy stack-protector support.
1080 ifneq ($(shell $(CONFIG_SHELL) $(stackp-check) $(CC) $(KBUILD_CPPFLAGS) $(biarch)),y)
1081 @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1082 $(stackp-flag) available but compiler is broken >&2 && exit 1
1087 # Generate some files
1088 # ---------------------------------------------------------------------------
1090 # KERNELRELEASE can change from a few different places, meaning version.h
1091 # needs to be updated, so this check is forced on all builds
1094 define filechk_utsrelease.h
1095 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1096 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1099 (echo \#define UTS_RELEASE \"$(KERNELRELEASE)\";)
1102 define filechk_version.h
1103 (echo \#define LINUX_VERSION_CODE $(shell \
1104 expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
1105 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))';)
1108 $(version_h): $(srctree)/Makefile FORCE
1109 $(call filechk,version.h)
1110 $(Q)rm -f $(old_version_h)
1112 include/generated/utsrelease.h: include/config/kernel.release FORCE
1113 $(call filechk,utsrelease.h)
1117 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1118 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1120 # ---------------------------------------------------------------------------
1122 INSTALL_FW_PATH=$(INSTALL_MOD_PATH)/lib/firmware
1123 export INSTALL_FW_PATH
1125 PHONY += firmware_install
1127 @mkdir -p $(objtree)/firmware
1128 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.fwinst obj=firmware __fw_install
1130 # ---------------------------------------------------------------------------
1133 #Default location for installed headers
1134 export INSTALL_HDR_PATH = $(objtree)/usr
1136 # If we do an all arch process set dst to asm-$(hdr-arch)
1137 hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(hdr-arch), dst=include)
1139 PHONY += archheaders
1142 PHONY += archscripts
1146 __headers: $(version_h) scripts_basic asm-generic archheaders archscripts
1147 $(Q)$(MAKE) $(build)=scripts build_unifdef
1149 PHONY += headers_install_all
1150 headers_install_all:
1151 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh install
1153 PHONY += headers_install
1154 headers_install: __headers
1155 $(if $(wildcard $(srctree)/arch/$(hdr-arch)/include/uapi/asm/Kbuild),, \
1156 $(error Headers not exportable for the $(SRCARCH) architecture))
1157 $(Q)$(MAKE) $(hdr-inst)=include/uapi
1158 $(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/uapi $(hdr-dst)
1160 PHONY += headers_check_all
1161 headers_check_all: headers_install_all
1162 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh check
1164 PHONY += headers_check
1165 headers_check: headers_install
1166 $(Q)$(MAKE) $(hdr-inst)=include/uapi HDRCHECK=1
1167 $(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/uapi $(hdr-dst) HDRCHECK=1
1169 # ---------------------------------------------------------------------------
1174 $(Q)$(MAKE) -C tools/testing/selftests run_tests
1177 $(Q)$(MAKE) -C tools/testing/selftests clean
1179 PHONY += kselftest-merge
1181 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1182 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \
1183 -m $(objtree)/.config \
1184 $(srctree)/tools/testing/selftests/*/config
1185 +$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1187 # ---------------------------------------------------------------------------
1190 ifdef CONFIG_MODULES
1192 # By default, build modules as well
1198 # A module can be listed more than once in obj-m resulting in
1199 # duplicate lines in modules.order files. Those are removed
1200 # using awk while concatenating to the final file.
1203 modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
1204 $(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
1205 @$(kecho) ' Building modules, stage 2.';
1206 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1207 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.fwinst obj=firmware __fw_modbuild
1209 modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
1210 $(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
1212 %/modules.builtin: include/config/auto.conf
1213 $(Q)$(MAKE) $(modbuiltin)=$*
1216 # Target to prepare building external modules
1217 PHONY += modules_prepare
1218 modules_prepare: prepare scripts
1220 # Target to install modules
1221 PHONY += modules_install
1222 modules_install: _modinst_ _modinst_post
1226 @rm -rf $(MODLIB)/kernel
1227 @rm -f $(MODLIB)/source
1228 @mkdir -p $(MODLIB)/kernel
1229 @ln -s `cd $(srctree) && /bin/pwd` $(MODLIB)/source
1230 @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
1231 rm -f $(MODLIB)/build ; \
1232 ln -s $(CURDIR) $(MODLIB)/build ; \
1234 @cp -f $(objtree)/modules.order $(MODLIB)/
1235 @cp -f $(objtree)/modules.builtin $(MODLIB)/
1236 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1238 # This depmod is only for convenience to give the initial
1239 # boot a modules.dep even before / is mounted read-write. However the
1240 # boot script depmod is the master version.
1241 PHONY += _modinst_post
1242 _modinst_post: _modinst_
1243 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.fwinst obj=firmware __fw_modinst
1246 ifeq ($(CONFIG_MODULE_SIG), y)
1247 PHONY += modules_sign
1249 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1252 else # CONFIG_MODULES
1254 # Modules not configured
1255 # ---------------------------------------------------------------------------
1257 PHONY += modules modules_install
1258 modules modules_install:
1260 @echo >&2 "The present kernel configuration has modules disabled."
1261 @echo >&2 "Type 'make config' and enable loadable module support."
1262 @echo >&2 "Then build a kernel with module support enabled."
1266 endif # CONFIG_MODULES
1269 # Cleaning is done on three levels.
1270 # make clean Delete most generated files
1271 # Leave enough to build external modules
1272 # make mrproper Delete the current configuration, and all generated files
1273 # make distclean Remove editor backup files, patch leftover files and the like
1275 # Directories & files removed with 'make clean'
1276 CLEAN_DIRS += $(MODVERDIR)
1278 # Directories & files removed with 'make mrproper'
1279 MRPROPER_DIRS += include/config usr/include include/generated \
1280 arch/*/include/generated .tmp_objdiff
1281 MRPROPER_FILES += .config .config.old .version .old_version \
1282 Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
1283 signing_key.pem signing_key.priv signing_key.x509 \
1284 x509.genkey extra_certificates signing_key.x509.keyid \
1285 signing_key.x509.signer vmlinux-gdb.py
1287 # clean - Delete most, but leave enough to build external modules
1289 clean: rm-dirs := $(CLEAN_DIRS)
1290 clean: rm-files := $(CLEAN_FILES)
1291 clean-dirs := $(addprefix _clean_, . $(vmlinux-alldirs) Documentation samples)
1293 PHONY += $(clean-dirs) clean archclean vmlinuxclean
1295 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1298 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1299 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1301 clean: archclean vmlinuxclean
1303 # mrproper - Delete all generated files, including .config
1305 mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS))
1306 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1307 mrproper-dirs := $(addprefix _mrproper_,scripts)
1309 PHONY += $(mrproper-dirs) mrproper archmrproper
1311 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1313 mrproper: clean archmrproper $(mrproper-dirs)
1322 @find $(srctree) $(RCS_FIND_IGNORE) \
1323 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1324 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1325 -o -name 'core' \) \
1326 -type f -print | xargs rm -f
1329 # Packaging of the kernel to various formats
1330 # ---------------------------------------------------------------------------
1331 # rpm target kept for backward compatibility
1332 package-dir := scripts/package
1335 $(Q)$(MAKE) $(build)=$(package-dir) $@
1336 %pkg: include/config/kernel.release FORCE
1337 $(Q)$(MAKE) $(build)=$(package-dir) $@
1338 rpm: include/config/kernel.release FORCE
1339 $(Q)$(MAKE) $(build)=$(package-dir) $@
1342 # Brief documentation of the typical targets used
1343 # ---------------------------------------------------------------------------
1345 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1346 boards := $(sort $(notdir $(boards)))
1347 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1348 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1352 @echo 'Cleaning targets:'
1353 @echo ' clean - Remove most generated files but keep the config and'
1354 @echo ' enough build support to build external modules'
1355 @echo ' mrproper - Remove all generated files + config + various backup files'
1356 @echo ' distclean - mrproper + remove editor backup and patch files'
1358 @echo 'Configuration targets:'
1359 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1361 @echo 'Other generic targets:'
1362 @echo ' all - Build all targets marked with [*]'
1363 @echo '* vmlinux - Build the bare kernel'
1364 @echo '* modules - Build all modules'
1365 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1366 @echo ' firmware_install- Install all firmware to INSTALL_FW_PATH'
1367 @echo ' (default: $$(INSTALL_MOD_PATH)/lib/firmware)'
1368 @echo ' dir/ - Build all files in dir and below'
1369 @echo ' dir/file.[ois] - Build specified target only'
1370 @echo ' dir/file.ll - Build the LLVM assembly file'
1371 @echo ' (requires compiler support for LLVM assembly generation)'
1372 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1373 @echo ' (requires a recent binutils and recent build (System.map))'
1374 @echo ' dir/file.ko - Build module including final link'
1375 @echo ' modules_prepare - Set up for building external modules'
1376 @echo ' tags/TAGS - Generate tags file for editors'
1377 @echo ' cscope - Generate cscope index'
1378 @echo ' gtags - Generate GNU GLOBAL index'
1379 @echo ' kernelrelease - Output the release version string (use with make -s)'
1380 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1381 @echo ' image_name - Output the image name (use with make -s)'
1382 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1383 echo ' (default: $(INSTALL_HDR_PATH))'; \
1385 @echo 'Static analysers:'
1386 @echo ' checkstack - Generate a list of stack hogs'
1387 @echo ' namespacecheck - Name space analysis on compiled kernel'
1388 @echo ' versioncheck - Sanity check on version.h usage'
1389 @echo ' includecheck - Check for duplicate included header files'
1390 @echo ' export_report - List the usages of all exported symbols'
1391 @echo ' headers_check - Sanity check on exported headers'
1392 @echo ' headerdep - Detect inclusion cycles in headers'
1393 @$(MAKE) -f $(srctree)/scripts/Makefile.help checker-help
1395 @echo 'Kernel selftest:'
1396 @echo ' kselftest - Build and run kernel selftest (run as root)'
1397 @echo ' Build, install, and boot kernel before'
1398 @echo ' running kselftest on it'
1399 @echo ' kselftest-clean - Remove all generated kselftest files'
1400 @echo ' kselftest-merge - Merge all the config dependencies of kselftest to existed'
1403 @echo 'Userspace tools targets:'
1404 @echo ' use "make tools/help"'
1405 @echo ' or "cd tools; make help"'
1407 @echo 'Kernel packaging:'
1408 @$(MAKE) $(build)=$(package-dir) help
1410 @echo 'Documentation targets:'
1411 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1413 @echo 'Architecture specific targets ($(SRCARCH)):'
1414 @$(if $(archhelp),$(archhelp),\
1415 echo ' No architecture specific help defined for $(SRCARCH)')
1418 $(foreach b, $(boards), \
1419 printf " %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1421 @$(if $(board-dirs), \
1422 $(foreach b, $(board-dirs), \
1423 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1424 printf " %-16s - Show all of the above\\n" help-boards; \
1427 @echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1428 @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
1429 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1430 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK (sparse by default)'
1431 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1432 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1433 @echo ' make W=n [targets] Enable extra gcc checks, n=1,2,3 where'
1434 @echo ' 1: warnings which may be relevant and do not occur too often'
1435 @echo ' 2: warnings which occur quite often but may still be relevant'
1436 @echo ' 3: more obscure warnings, can most likely be ignored'
1437 @echo ' Multiple levels can be combined with W=12 or W=123'
1439 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1440 @echo 'For further info see the ./README file'
1443 help-board-dirs := $(addprefix help-,$(board-dirs))
1445 help-boards: $(help-board-dirs)
1447 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1449 $(help-board-dirs): help-%:
1450 @echo 'Architecture specific targets ($(SRCARCH) $*):'
1451 @$(if $(boards-per-dir), \
1452 $(foreach b, $(boards-per-dir), \
1453 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1457 # Documentation targets
1458 # ---------------------------------------------------------------------------
1459 DOC_TARGETS := xmldocs sgmldocs psdocs latexdocs pdfdocs htmldocs mandocs installmandocs epubdocs cleandocs linkcheckdocs
1460 PHONY += $(DOC_TARGETS)
1461 $(DOC_TARGETS): scripts_basic FORCE
1462 $(Q)$(MAKE) $(build)=Documentation $@
1464 else # KBUILD_EXTMOD
1467 # External module support.
1468 # When building external modules the kernel used as basis is considered
1469 # read-only, and no consistency checks are made and the make
1470 # system is not used on the basis kernel. If updates are required
1471 # in the basis kernel ordinary make commands (without M=...) must
1474 # The following are the only valid targets when building external
1476 # make M=dir clean Delete all automatically generated files
1477 # make M=dir modules Make all modules in specified dir
1478 # make M=dir Same as 'make M=dir modules'
1479 # make M=dir modules_install
1480 # Install the modules built in the module directory
1481 # Assumes install directory is already created
1483 # We are always building modules
1485 PHONY += crmodverdir
1489 PHONY += $(objtree)/Module.symvers
1490 $(objtree)/Module.symvers:
1491 @test -e $(objtree)/Module.symvers || ( \
1493 echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1494 echo " is missing; modules will have no dependencies and modversions."; \
1497 module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
1498 PHONY += $(module-dirs) modules
1499 $(module-dirs): crmodverdir $(objtree)/Module.symvers
1500 $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
1502 modules: $(module-dirs)
1503 @$(kecho) ' Building modules, stage 2.';
1504 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1506 PHONY += modules_install
1507 modules_install: _emodinst_ _emodinst_post
1509 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1512 $(Q)mkdir -p $(MODLIB)/$(install-dir)
1513 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1515 PHONY += _emodinst_post
1516 _emodinst_post: _emodinst_
1519 clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))
1521 PHONY += $(clean-dirs) clean
1523 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1525 clean: rm-dirs := $(MODVERDIR)
1526 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1530 @echo ' Building external modules.'
1531 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1533 @echo ' modules - default target, build the module(s)'
1534 @echo ' modules_install - install the module'
1535 @echo ' clean - remove generated files in module directory only'
1539 PHONY += prepare scripts
1542 endif # KBUILD_EXTMOD
1544 clean: $(clean-dirs)
1547 @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1548 \( -name '*.[oas]' -o -name '*.ko' -o -name '.*.cmd' \
1552 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1553 -o -name '*.symtypes' -o -name 'modules.order' \
1554 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1555 -o -name '*.c.[012]*.*' \
1557 -o -name '*.gcno' \) -type f -print | xargs rm -f
1559 # Generate tags for editors
1560 # ---------------------------------------------------------------------------
1561 quiet_cmd_tags = GEN $@
1562 cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
1564 tags TAGS cscope gtags: FORCE
1567 # Scripts to check various things for consistency
1568 # ---------------------------------------------------------------------------
1570 PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1573 find $(srctree)/* $(RCS_FIND_IGNORE) \
1574 -name '*.[hcS]' -type f -print | sort \
1575 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1578 find $(srctree)/* $(RCS_FIND_IGNORE) \
1579 -name '*.[hcS]' -type f -print | sort \
1580 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1583 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1586 $(PERL) $(srctree)/scripts/namespace.pl
1589 $(PERL) $(srctree)/scripts/export_report.pl
1591 endif #ifeq ($(config-targets),1)
1592 endif #ifeq ($(mixed-targets),1)
1594 PHONY += checkstack kernelrelease kernelversion image_name
1596 # UML needs a little special treatment here. It wants to use the host
1597 # toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
1598 # else wants $(ARCH), including people doing cross-builds, which means
1599 # that $(SUBARCH) doesn't work here.
1601 CHECKSTACK_ARCH := $(SUBARCH)
1603 CHECKSTACK_ARCH := $(ARCH)
1606 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1607 $(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1610 @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1613 @echo $(KERNELVERSION)
1616 @echo $(KBUILD_IMAGE)
1618 # Clear a bunch of variables before executing the submake
1620 $(Q)mkdir -p $(objtree)/tools
1621 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(shell cd $(objtree) && /bin/pwd) subdir=tools -C $(src)/tools/
1624 $(Q)mkdir -p $(objtree)/tools
1625 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(shell cd $(objtree) && /bin/pwd) subdir=tools -C $(src)/tools/ $*
1628 # ---------------------------------------------------------------------------
1629 # Single targets are compatible with:
1630 # - build with mixed source and output
1631 # - build with separate output dir 'make O=...'
1632 # - external modules
1634 # target-dir => where to store outputfile
1635 # build-dir => directory in kernel source tree to use
1637 ifeq ($(KBUILD_EXTMOD),)
1638 build-dir = $(patsubst %/,%,$(dir $@))
1639 target-dir = $(dir $@)
1641 zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
1642 build-dir = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
1643 target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@))
1646 %.s: %.c prepare scripts FORCE
1647 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1648 %.i: %.c prepare scripts FORCE
1649 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1650 %.o: %.c prepare scripts FORCE
1651 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1652 %.lst: %.c prepare scripts FORCE
1653 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1654 %.s: %.S prepare scripts FORCE
1655 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1656 %.o: %.S prepare scripts FORCE
1657 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1658 %.symtypes: %.c prepare scripts FORCE
1659 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1660 %.ll: %.c prepare scripts FORCE
1661 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1664 /: prepare scripts FORCE
1666 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1667 $(build)=$(build-dir)
1668 # Make sure the latest headers are built for Documentation
1669 Documentation/ samples/: headers_install
1670 %/: prepare scripts FORCE
1672 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1673 $(build)=$(build-dir)
1674 %.ko: prepare scripts FORCE
1676 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1677 $(build)=$(build-dir) $(@:.ko=.o)
1678 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1680 # FIXME Should go into a make.lib or something
1681 # ===========================================================================
1683 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs)))
1684 cmd_rmdirs = rm -rf $(rm-dirs)
1686 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
1687 cmd_rmfiles = rm -f $(rm-files)
1689 # Run depmod only if we have System.map and depmod is executable
1690 quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
1691 cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1692 $(KERNELRELEASE) "$(patsubst y,_,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))"
1694 # Create temporary dir for module support files
1695 # clean it up only when building all modules
1696 cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
1697 $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
1699 # read all saved command lines
1701 targets := $(wildcard $(sort $(targets)))
1702 cmd_files := $(wildcard .*.cmd $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
1704 ifneq ($(cmd_files),)
1705 $(cmd_files): ; # Do not try to update included dependency files
1706 include $(cmd_files)
1709 endif # skip-makefile
1714 # Declare the contents of the .PHONY variable as phony. We keep that
1715 # information in a variable so we can use it in if_changed and friends.