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 # That's our default target when none is given on the command line
17 # o Do not use make's built-in rules and variables
18 # (this increases performance and avoids hard-to-debug behaviour);
19 # o Look for make include files relative to root of kernel src
20 MAKEFLAGS += -rR --include-dir=$(CURDIR)
22 # Avoid funny character set dependencies
26 export LC_COLLATE LC_NUMERIC
28 # Avoid interference with shell env settings
31 # We are using a recursive build, so we need to do a little thinking
32 # to get the ordering right.
34 # Most importantly: sub-Makefiles should only ever modify files in
35 # their own directory. If in some directory we have a dependency on
36 # a file in another dir (which doesn't happen often, but it's often
37 # unavoidable when linking the built-in.o targets which finally
38 # turn into vmlinux), we will call a sub make in that other dir, and
39 # after that we are sure that everything which is in that other dir
42 # The only cases where we need to modify files which have global
43 # effects are thus separated out and done before the recursive
44 # descending is started. They are now explicitly listed as the
48 # ---------------------------------------------------------------------------
50 # Normally, we echo the whole command before executing it. By making
51 # that echo $($(quiet)$(cmd)), we now have the possibility to set
52 # $(quiet) to choose other forms of output instead, e.g.
54 # quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
55 # cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
57 # If $(quiet) is empty, the whole command will be printed.
58 # If it is set to "quiet_", only the short version will be printed.
59 # If it is set to "silent_", nothing will be printed at all, since
60 # the variable $(silent_cmd_cc_o_c) doesn't exist.
62 # A simple variant is to prefix commands with $(Q) - that's useful
63 # for commands that shall be hidden in non-verbose mode.
67 # If KBUILD_VERBOSE equals 0 then the above command will be hidden.
68 # If KBUILD_VERBOSE equals 1 then the above command is displayed.
70 # To put more focus on warnings, be less verbose as default
71 # Use 'make V=1' to see the full commands
73 ifeq ("$(origin V)", "command line")
80 ifeq ($(KBUILD_VERBOSE),1)
88 # If the user is running make -s (silent mode), suppress echoing of
91 ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
96 export quiet Q KBUILD_VERBOSE
98 # kbuild supports saving output files in a separate directory.
99 # To locate output files in a separate directory two syntaxes are supported.
100 # In both cases the working directory must be the root of the kernel src.
102 # Use "make O=dir/to/store/output/files/"
104 # 2) Set KBUILD_OUTPUT
105 # Set the environment variable KBUILD_OUTPUT to point to the directory
106 # where the output files shall be placed.
107 # export KBUILD_OUTPUT=dir/to/store/output/files/
110 # The O= assignment takes precedence over the KBUILD_OUTPUT environment
113 # KBUILD_SRC is not intended to be used by the regular user (for now),
114 # it is set on invocation of make with KBUILD_OUTPUT or O= specified.
115 ifeq ($(KBUILD_SRC),)
117 # OK, Make called in directory where kernel src resides
118 # Do we want to locate output files in a separate directory?
119 ifeq ("$(origin O)", "command line")
120 KBUILD_OUTPUT := $(O)
123 # Cancel implicit rules on top Makefile
124 $(CURDIR)/Makefile Makefile: ;
126 ifneq ($(words $(subst :, ,$(CURDIR))), 1)
127 $(error main directory cannot contain spaces nor colons)
130 ifneq ($(KBUILD_OUTPUT),)
131 # check that the output directory actually exists
132 saved-output := $(KBUILD_OUTPUT)
133 $(shell [ -d $(KBUILD_OUTPUT) ] || mkdir -p $(KBUILD_OUTPUT))
134 KBUILD_OUTPUT := $(realpath $(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 := $(M)
189 ifeq ($(KBUILD_SRC),)
190 # building in the source tree
193 ifeq ($(KBUILD_SRC)/,$(dir $(CURDIR)))
194 # building in a subdirectory of the source tree
197 srctree := $(KBUILD_SRC)
201 export KBUILD_CHECKSRC KBUILD_EXTMOD KBUILD_SRC
207 VPATH := $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))
209 export srctree objtree VPATH
211 # To make sure we do not include .config for any of the *config targets
212 # catch them early, and hand them over to scripts/kconfig/Makefile
213 # It is allowed to specify more targets when calling make, including
214 # mixing *config targets and build targets.
215 # For example 'make oldconfig all'.
216 # Detect when mixed targets is specified, and make a second invocation
217 # of make so .config is not included in this case either (for *config).
219 version_h := include/generated/uapi/linux/version.h
220 old_version_h := include/linux/version.h
222 no-dot-config-targets := clean mrproper distclean \
223 cscope gtags TAGS tags help% %docs check% coccicheck \
224 $(version_h) headers_% archheaders archscripts \
225 kernelversion %src-pkg
231 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
232 ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
237 ifeq ($(KBUILD_EXTMOD),)
238 ifneq ($(filter config %config,$(MAKECMDGOALS)),)
240 ifneq ($(words $(MAKECMDGOALS)),1)
245 # install and modules_install need also be processed one by one
246 ifneq ($(filter install,$(MAKECMDGOALS)),)
247 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
252 ifeq ($(mixed-targets),1)
253 # ===========================================================================
254 # We're called with mixed targets (*config and build targets).
255 # Handle them one by one.
257 PHONY += $(MAKECMDGOALS) __build_one_by_one
259 $(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
264 for i in $(MAKECMDGOALS); do \
265 $(MAKE) -f $(srctree)/Makefile $$i; \
270 # We need some generic definitions (do not try to remake the file).
271 scripts/Kbuild.include: ;
272 include scripts/Kbuild.include
274 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
275 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
276 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
277 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
279 # SUBARCH tells the usermode build what the underlying arch is. That is set
280 # first, and if a usermode build is happening, the "ARCH=um" on the command
281 # line overrides the setting of ARCH below. If a native build is happening,
282 # then ARCH is assigned, getting whatever value it gets normally, and
283 # SUBARCH is subsequently ignored.
285 SUBARCH := $(shell uname -m | sed -e s/i.86/x86/ -e s/x86_64/x86/ \
286 -e s/sun4u/sparc64/ \
287 -e s/arm.*/arm/ -e s/sa110/arm/ \
288 -e s/s390x/s390/ -e s/parisc64/parisc/ \
289 -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
290 -e s/sh[234].*/sh/ -e s/aarch64.*/arm64/ )
292 # Cross compiling and selecting different set of gcc/bin-utils
293 # ---------------------------------------------------------------------------
295 # When performing cross compilation for other architectures ARCH shall be set
296 # to the target architecture. (See arch/* for the possibilities).
297 # ARCH can be set during invocation of make:
299 # Another way is to have ARCH set in the environment.
300 # The default ARCH is the host where make is executed.
302 # CROSS_COMPILE specify the prefix used for all executables used
303 # during compilation. Only gcc and related bin-utils executables
304 # are prefixed with $(CROSS_COMPILE).
305 # CROSS_COMPILE can be set on the command line
306 # make CROSS_COMPILE=ia64-linux-
307 # Alternatively CROSS_COMPILE can be set in the environment.
308 # A third alternative is to store a setting in .config so that plain
309 # "make" in the configured kernel build directory always uses that.
310 # Default value for CROSS_COMPILE is not to prefix executables
311 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
313 CROSS_COMPILE ?= $(CONFIG_CROSS_COMPILE:"%"=%)
315 # Architecture as present in compile.h
316 UTS_MACHINE := $(ARCH)
319 # Additional ARCH settings for x86
323 ifeq ($(ARCH),x86_64)
327 # Additional ARCH settings for sparc
328 ifeq ($(ARCH),sparc32)
331 ifeq ($(ARCH),sparc64)
335 # Additional ARCH settings for sh
340 # Additional ARCH settings for tile
341 ifeq ($(ARCH),tilepro)
344 ifeq ($(ARCH),tilegx)
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
379 GENKSYMS = scripts/genksyms/genksyms
380 INSTALLKERNEL := installkernel
381 DEPMOD = /sbin/depmod
386 CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
387 -Wbitwise -Wno-return-void $(CF)
396 # Use USERINCLUDE when you must reference the UAPI directories only.
398 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
399 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
400 -I$(srctree)/include/uapi \
401 -I$(objtree)/include/generated/uapi \
402 -include $(srctree)/include/linux/kconfig.h
404 # Use LINUXINCLUDE when you must reference the include/ directory.
405 # Needed to be compatible with the O= option
407 -I$(srctree)/arch/$(SRCARCH)/include \
408 -I$(objtree)/arch/$(SRCARCH)/include/generated \
409 $(if $(KBUILD_SRC), -I$(srctree)/include) \
410 -I$(objtree)/include \
413 KBUILD_AFLAGS := -D__ASSEMBLY__
414 KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
415 -fno-strict-aliasing -fno-common -fshort-wchar \
416 -Werror-implicit-function-declaration \
417 -Wno-format-security \
419 KBUILD_CPPFLAGS := -D__KERNEL__
420 KBUILD_AFLAGS_KERNEL :=
421 KBUILD_CFLAGS_KERNEL :=
422 KBUILD_AFLAGS_MODULE := -DMODULE
423 KBUILD_CFLAGS_MODULE := -DMODULE
424 KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
425 GCC_PLUGINS_CFLAGS :=
427 export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC
428 export CPP AR NM STRIP OBJCOPY OBJDUMP HOSTLDFLAGS HOST_LOADLIBES
429 export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE
430 export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
432 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
433 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_KASAN CFLAGS_UBSAN
434 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
435 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
436 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
437 export KBUILD_ARFLAGS
439 # When compiling out-of-tree modules, put MODVERDIR in the module
440 # tree rather than in the kernel tree. The kernel tree might
442 export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
444 # Files to ignore in find ... statements
446 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
447 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
449 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
450 --exclude CVS --exclude .pc --exclude .hg --exclude .git
452 # ===========================================================================
453 # Rules shared between *config targets and build targets
455 # Basic helpers built in scripts/basic/
456 PHONY += scripts_basic
458 $(Q)$(MAKE) $(build)=scripts/basic
459 $(Q)rm -f .tmp_quiet_recordmcount
461 # To avoid any implicit rule to kick in, define an empty command.
462 scripts/basic/%: scripts_basic ;
464 PHONY += outputmakefile
465 # outputmakefile generates a Makefile in the output directory, if using a
466 # separate output directory. This allows convenient use of make in the
469 ifneq ($(KBUILD_SRC),)
470 $(Q)ln -fsn $(srctree) source
471 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile \
472 $(srctree) $(objtree) $(VERSION) $(PATCHLEVEL)
475 ifeq ($(config-targets),1)
476 # ===========================================================================
477 # *config targets only - make sure prerequisites are updated, and descend
478 # in scripts/kconfig to make the *config target
480 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
481 # KBUILD_DEFCONFIG may point out an alternative default configuration
482 # used for 'make defconfig'
483 include arch/$(SRCARCH)/Makefile
484 export KBUILD_DEFCONFIG KBUILD_KCONFIG
486 config: scripts_basic outputmakefile FORCE
487 $(Q)$(MAKE) $(build)=scripts/kconfig $@
489 %config: scripts_basic outputmakefile FORCE
490 $(Q)$(MAKE) $(build)=scripts/kconfig $@
493 # ===========================================================================
494 # Build targets only - this includes vmlinux, arch specific targets, clean
495 # targets and others. In general all targets except *config targets.
497 # If building an external module we do not care about the all: rule
498 # but instead _all depend on modules
500 ifeq ($(KBUILD_EXTMOD),)
506 # Decide whether to build built-in, modular, or both.
507 # Normally, just do built-in.
512 # If we have only "make modules", don't compile built-in objects.
513 # When we're building modules with modversions, we need to consider
514 # the built-in objects during the descend as well, in order to
515 # make sure the checksums are up to date before we record them.
517 ifeq ($(MAKECMDGOALS),modules)
518 KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
521 # If we have "make <whatever> modules", compile modules
522 # in addition to whatever we do anyway.
523 # Just "make" or "make all" shall build modules as well
525 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
529 ifeq ($(MAKECMDGOALS),)
533 export KBUILD_MODULES KBUILD_BUILTIN
535 ifeq ($(KBUILD_EXTMOD),)
536 # Additional helpers built in scripts/
537 # Carefully list dependencies so we do not try to build scripts twice
540 scripts: scripts_basic include/config/auto.conf include/config/tristate.conf \
541 asm-generic gcc-plugins
542 $(Q)$(MAKE) $(build)=$(@)
544 # Objects we will link into vmlinux / subdirs we need to visit
546 drivers-y := drivers/ sound/ firmware/
551 endif # KBUILD_EXTMOD
553 ifeq ($(dot-config),1)
555 -include include/config/auto.conf
557 ifeq ($(KBUILD_EXTMOD),)
558 # Read in dependencies to all Kconfig* files, make sure to run
559 # oldconfig if changes are detected.
560 -include include/config/auto.conf.cmd
562 # To avoid any implicit rule to kick in, define an empty command
563 $(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;
565 # If .config is newer than include/config/auto.conf, someone tinkered
566 # with it and forgot to run make oldconfig.
567 # if auto.conf.cmd is missing then we are probably in a cleaned tree so
568 # we execute the config step to be sure to catch updated Kconfig files
569 include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
570 $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig
572 # external modules needs include/generated/autoconf.h and include/config/auto.conf
573 # but do not care if they are up-to-date. Use auto.conf to trigger the test
574 PHONY += include/config/auto.conf
576 include/config/auto.conf:
577 $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
579 echo >&2 " ERROR: Kernel configuration is invalid."; \
580 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
581 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
585 endif # KBUILD_EXTMOD
588 # Dummy target needed, because used as prerequisite
589 include/config/auto.conf: ;
590 endif # $(dot-config)
592 # For the kernel to actually contain only the needed exported symbols,
593 # we have to build modules as well to determine what those symbols are.
594 # (this can be evaluated only once include/config/auto.conf has been included)
595 ifdef CONFIG_TRIM_UNUSED_KSYMS
599 # The all: target is the default when no target is given on the
601 # This allow a user to issue only 'make' to build a kernel including modules
602 # Defaults to vmlinux, but the arch makefile usually adds further targets
605 KBUILD_CFLAGS += $(call cc-option,-fno-PIE)
606 KBUILD_AFLAGS += $(call cc-option,-fno-PIE)
607 CFLAGS_GCOV := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,)
608 CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,)
609 export CFLAGS_GCOV CFLAGS_KCOV
611 # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
612 # values of the respective KBUILD_* variables
616 include arch/$(SRCARCH)/Makefile
618 KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
619 KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
620 KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
621 KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
622 KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context)
624 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
625 KBUILD_CFLAGS += $(call cc-option,-Oz,-Os)
626 KBUILD_CFLAGS += $(call cc-disable-warning,maybe-uninitialized,)
628 ifdef CONFIG_PROFILE_ALL_BRANCHES
629 KBUILD_CFLAGS += -O2 $(call cc-disable-warning,maybe-uninitialized,)
635 KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \
636 $(call cc-disable-warning,maybe-uninitialized,))
638 # Tell gcc to never replace conditional load with a non-conditional one
639 KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
641 # check for 'asm goto'
642 ifeq ($(call shell-cached,$(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y)
643 KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
644 KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO
647 include scripts/Makefile.gcc-plugins
649 ifdef CONFIG_READABLE_ASM
650 # Disable optimizations that make assembler listings hard to read.
651 # reorder blocks reorders the control in the function
652 # ipa clone creates specialized cloned functions
653 # partial inlining inlines only parts of functions
654 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
655 $(call cc-option,-fno-ipa-cp-clone,) \
656 $(call cc-option,-fno-partial-inlining)
659 ifneq ($(CONFIG_FRAME_WARN),0)
660 KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
663 # This selects the stack protector compiler flag. Testing it is delayed
664 # until after .config has been reprocessed, in the prepare-compiler-check
666 ifdef CONFIG_CC_STACKPROTECTOR_REGULAR
667 stackp-flag := -fstack-protector
668 stackp-name := REGULAR
670 ifdef CONFIG_CC_STACKPROTECTOR_STRONG
671 stackp-flag := -fstack-protector-strong
672 stackp-name := STRONG
674 # Force off for distro compilers that enable stack protector by default.
675 stackp-flag := $(call cc-option, -fno-stack-protector)
678 # Find arch-specific stack protector compiler sanity-checking script.
679 ifdef CONFIG_CC_STACKPROTECTOR
680 stackp-path := $(srctree)/scripts/gcc-$(SRCARCH)_$(BITS)-has-stack-protector.sh
681 stackp-check := $(wildcard $(stackp-path))
683 KBUILD_CFLAGS += $(stackp-flag)
685 ifeq ($(cc-name),clang)
686 ifneq ($(CROSS_COMPILE),)
687 CLANG_TARGET := -target $(notdir $(CROSS_COMPILE:%-=%))
688 GCC_TOOLCHAIN := $(realpath $(dir $(shell which $(LD)))/..)
690 ifneq ($(GCC_TOOLCHAIN),)
691 CLANG_GCC_TC := -gcc-toolchain $(GCC_TOOLCHAIN)
693 KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
694 KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
695 KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
696 KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable)
697 KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
698 KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
699 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
700 # Quiet clang warning: comparison of unsigned expression < 0 is always false
701 KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
702 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
703 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
704 # See modpost pattern 2
705 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
706 KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
707 KBUILD_CFLAGS += $(call cc-option, -no-integrated-as)
708 KBUILD_AFLAGS += $(call cc-option, -no-integrated-as)
711 # These warnings generated too much noise in a regular build.
712 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
713 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
714 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
717 ifdef CONFIG_FRAME_POINTER
718 KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
720 # Some targets (ARM with Thumb2, for example), can't be built with frame
721 # pointers. For those, we don't have FUNCTION_TRACER automatically
722 # select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
723 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
724 # -fomit-frame-pointer with FUNCTION_TRACER.
725 ifndef CONFIG_FUNCTION_TRACER
726 KBUILD_CFLAGS += -fomit-frame-pointer
730 KBUILD_CFLAGS += $(call cc-option, -fno-var-tracking-assignments)
732 ifdef CONFIG_DEBUG_INFO
733 ifdef CONFIG_DEBUG_INFO_SPLIT
734 KBUILD_CFLAGS += $(call cc-option, -gsplit-dwarf, -g)
738 KBUILD_AFLAGS += -Wa,-gdwarf-2
740 ifdef CONFIG_DEBUG_INFO_DWARF4
741 KBUILD_CFLAGS += $(call cc-option, -gdwarf-4,)
744 ifdef CONFIG_DEBUG_INFO_REDUCED
745 KBUILD_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
746 $(call cc-option,-fno-var-tracking)
749 ifdef CONFIG_FUNCTION_TRACER
750 ifndef CC_FLAGS_FTRACE
751 CC_FLAGS_FTRACE := -pg
753 export CC_FLAGS_FTRACE
754 ifdef CONFIG_HAVE_FENTRY
755 CC_USING_FENTRY := $(call cc-option, -mfentry -DCC_USING_FENTRY)
757 KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_USING_FENTRY)
758 KBUILD_AFLAGS += $(CC_USING_FENTRY)
759 ifdef CONFIG_DYNAMIC_FTRACE
760 ifdef CONFIG_HAVE_C_RECORDMCOUNT
761 BUILD_C_RECORDMCOUNT := y
762 export BUILD_C_RECORDMCOUNT
767 # We trigger additional mismatches with less inlining
768 ifdef CONFIG_DEBUG_SECTION_MISMATCH
769 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
772 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
773 KBUILD_CFLAGS += $(call cc-option,-ffunction-sections,)
774 KBUILD_CFLAGS += $(call cc-option,-fdata-sections,)
777 # arch Makefile may override CC so keep this after arch Makefile is included
778 NOSTDINC_FLAGS += -nostdinc -isystem $(call shell-cached,$(CC) -print-file-name=include)
779 CHECKFLAGS += $(NOSTDINC_FLAGS)
781 # warn about C99 declaration after statement
782 KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
784 # disable pointer signed / unsigned warnings in gcc 4.0
785 KBUILD_CFLAGS += $(call cc-disable-warning, pointer-sign)
787 # disable invalid "can't wrap" optimizations for signed / pointers
788 KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
790 # conserve stack if available
791 KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
793 # disallow errors like 'EXPORT_GPL(foo);' with missing header
794 KBUILD_CFLAGS += $(call cc-option,-Werror=implicit-int)
796 # require functions to have arguments in prototypes, not empty 'int foo()'
797 KBUILD_CFLAGS += $(call cc-option,-Werror=strict-prototypes)
799 # Prohibit date/time macros, which would make the build non-deterministic
800 KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
802 # enforce correct pointer usage
803 KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
805 # Require designated initializers for all marked structures
806 KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
808 # use the deterministic mode of AR if available
809 KBUILD_ARFLAGS := $(call ar-option,D)
811 include scripts/Makefile.kasan
812 include scripts/Makefile.extrawarn
813 include scripts/Makefile.ubsan
815 # Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
817 KBUILD_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS)
818 KBUILD_AFLAGS += $(ARCH_AFLAGS) $(KAFLAGS)
819 KBUILD_CFLAGS += $(ARCH_CFLAGS) $(KCFLAGS)
821 # Use --build-id when available.
822 LDFLAGS_BUILD_ID := $(patsubst -Wl$(comma)%,%,\
823 $(call cc-ldoption, -Wl$(comma)--build-id,))
824 KBUILD_LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
825 LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
827 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
828 LDFLAGS_vmlinux += $(call ld-option, --gc-sections,)
831 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
832 LDFLAGS_vmlinux += $(call ld-option, -X,)
835 # Default kernel image to build when no specific target is given.
836 # KBUILD_IMAGE may be overruled on the command line or
837 # set in the environment
838 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
840 export KBUILD_IMAGE ?= vmlinux
843 # INSTALL_PATH specifies where to place the updated kernel and system map
844 # images. Default is /boot, but you can set it to other values
845 export INSTALL_PATH ?= /boot
848 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
849 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
850 # an argument if needed. Otherwise it defaults to the kernel install path
852 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
855 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
856 # relocations required by build roots. This is not defined in the
857 # makefile but the argument can be passed to make if needed.
860 MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
864 # INSTALL_MOD_STRIP, if defined, will cause modules to be
865 # stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
866 # the default option --strip-debug will be used. Otherwise,
867 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
869 ifdef INSTALL_MOD_STRIP
870 ifeq ($(INSTALL_MOD_STRIP),1)
871 mod_strip_cmd = $(STRIP) --strip-debug
873 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
874 endif # INSTALL_MOD_STRIP=1
877 endif # INSTALL_MOD_STRIP
880 # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
881 # after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
882 # or CONFIG_MODULE_COMPRESS_XZ.
884 mod_compress_cmd = true
885 ifdef CONFIG_MODULE_COMPRESS
886 ifdef CONFIG_MODULE_COMPRESS_GZIP
887 mod_compress_cmd = gzip -n -f
888 endif # CONFIG_MODULE_COMPRESS_GZIP
889 ifdef CONFIG_MODULE_COMPRESS_XZ
890 mod_compress_cmd = xz -f
891 endif # CONFIG_MODULE_COMPRESS_XZ
892 endif # CONFIG_MODULE_COMPRESS
893 export mod_compress_cmd
895 # Select initial ramdisk compression format, default is gzip(1).
896 # This shall be used by the dracut(8) tool while creating an initramfs image.
898 INITRD_COMPRESS-y := gzip
899 INITRD_COMPRESS-$(CONFIG_RD_BZIP2) := bzip2
900 INITRD_COMPRESS-$(CONFIG_RD_LZMA) := lzma
901 INITRD_COMPRESS-$(CONFIG_RD_XZ) := xz
902 INITRD_COMPRESS-$(CONFIG_RD_LZO) := lzo
903 INITRD_COMPRESS-$(CONFIG_RD_LZ4) := lz4
904 # do not export INITRD_COMPRESS, since we didn't actually
905 # choose a sane default compression above.
906 # export INITRD_COMPRESS := $(INITRD_COMPRESS-y)
908 ifdef CONFIG_MODULE_SIG_ALL
909 $(eval $(call config_filename,MODULE_SIG_KEY))
911 mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
917 ifdef CONFIG_STACK_VALIDATION
918 has_libelf := $(call try-run,\
919 echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0)
920 ifeq ($(has_libelf),1)
921 objtool_target := tools/objtool FORCE
923 $(warning "Cannot use CONFIG_STACK_VALIDATION, please install libelf-dev, libelf-devel or elfutils-libelf-devel")
924 SKIP_STACK_VALIDATION := 1
925 export SKIP_STACK_VALIDATION
930 ifeq ($(KBUILD_EXTMOD),)
931 core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
933 vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
934 $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
935 $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
937 vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
938 $(init-) $(core-) $(drivers-) $(net-) $(libs-) $(virt-))))
940 init-y := $(patsubst %/, %/built-in.o, $(init-y))
941 core-y := $(patsubst %/, %/built-in.o, $(core-y))
942 drivers-y := $(patsubst %/, %/built-in.o, $(drivers-y))
943 net-y := $(patsubst %/, %/built-in.o, $(net-y))
944 libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
945 libs-y2 := $(filter-out %.a, $(patsubst %/, %/built-in.o, $(libs-y)))
946 virt-y := $(patsubst %/, %/built-in.o, $(virt-y))
948 # Externally visible symbols (used by link-vmlinux.sh)
949 export KBUILD_VMLINUX_INIT := $(head-y) $(init-y)
950 export KBUILD_VMLINUX_MAIN := $(core-y) $(libs-y2) $(drivers-y) $(net-y) $(virt-y)
951 export KBUILD_VMLINUX_LIBS := $(libs-y1)
952 export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
953 export LDFLAGS_vmlinux
954 # used by scripts/package/Makefile
955 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools)
957 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_INIT) $(KBUILD_VMLINUX_MAIN) $(KBUILD_VMLINUX_LIBS)
959 # Include targets which we want to execute sequentially if the rest of the
960 # kernel build went well. If CONFIG_TRIM_UNUSED_KSYMS is set, this might be
961 # evaluated more than once.
962 PHONY += vmlinux_prereq
963 vmlinux_prereq: $(vmlinux-deps) FORCE
964 ifdef CONFIG_HEADERS_CHECK
965 $(Q)$(MAKE) -f $(srctree)/Makefile headers_check
967 ifdef CONFIG_GDB_SCRIPTS
968 $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
970 ifdef CONFIG_TRIM_UNUSED_KSYMS
971 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
972 "$(MAKE) -f $(srctree)/Makefile vmlinux"
975 # standalone target for easier testing
976 include/generated/autoksyms.h: FORCE
977 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh true
979 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
981 # Final link of vmlinux with optional arch pass after final link
983 $(CONFIG_SHELL) $< $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) ; \
984 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
986 vmlinux: scripts/link-vmlinux.sh vmlinux_prereq $(vmlinux-deps) FORCE
987 +$(call if_changed,link-vmlinux)
989 # Build samples along the rest of the kernel
991 vmlinux-dirs += samples
994 # The actual objects are generated when descending,
995 # make sure no implicit rule kicks in
996 $(sort $(vmlinux-deps)): $(vmlinux-dirs) ;
998 # Handle descending into subdirectories listed in $(vmlinux-dirs)
999 # Preset locale variables to speed up the build process. Limit locale
1000 # tweaks to this spot to avoid wrong language settings when running
1001 # make menuconfig etc.
1002 # Error messages still appears in the original language
1004 PHONY += $(vmlinux-dirs)
1005 $(vmlinux-dirs): prepare scripts
1006 $(Q)$(MAKE) $(build)=$@
1008 define filechk_kernel.release
1009 echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1012 # Store (new) KERNELRELEASE string in include/config/kernel.release
1013 include/config/kernel.release: include/config/auto.conf FORCE
1014 $(call filechk,kernel.release)
1017 # Things we need to do before we recursively start building the kernel
1018 # or the modules are listed in "prepare".
1019 # A multi level approach is used. prepareN is processed before prepareN-1.
1020 # archprepare is used in arch Makefiles and when processed asm symlink,
1021 # version.h and scripts_basic is processed / created.
1023 # Listed in dependency order
1024 PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3
1026 # prepare3 is used to check if we are building in a separate output directory,
1028 # 1) Check that make has not been executed in the kernel src $(srctree)
1029 prepare3: include/config/kernel.release
1030 ifneq ($(KBUILD_SRC),)
1031 @$(kecho) ' Using $(srctree) as source for kernel'
1032 $(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
1033 echo >&2 " $(srctree) is not clean, please run 'make mrproper'"; \
1034 echo >&2 " in the '$(srctree)' directory.";\
1039 # prepare2 creates a makefile if using a separate output directory.
1040 # From this point forward, .config has been reprocessed, so any rules
1041 # that need to depend on updated CONFIG_* values can be checked here.
1042 prepare2: prepare3 prepare-compiler-check outputmakefile asm-generic
1044 prepare1: prepare2 $(version_h) include/generated/utsrelease.h \
1045 include/config/auto.conf
1048 archprepare: archheaders archscripts prepare1 scripts_basic
1050 prepare0: archprepare gcc-plugins
1051 $(Q)$(MAKE) $(build)=.
1053 # All the preparing..
1054 prepare: prepare0 prepare-objtool
1056 # Support for using generic headers in asm-generic
1057 PHONY += asm-generic uapi-asm-generic
1058 asm-generic: uapi-asm-generic
1059 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
1060 src=asm obj=arch/$(SRCARCH)/include/generated/asm
1062 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
1063 src=uapi/asm obj=arch/$(SRCARCH)/include/generated/uapi/asm
1065 PHONY += prepare-objtool
1066 prepare-objtool: $(objtool_target)
1068 # Check for CONFIG flags that require compiler support. Abort the build
1069 # after .config has been processed, but before the kernel build starts.
1071 # For security-sensitive CONFIG options, we don't want to fallback and/or
1072 # silently change which compiler flags will be used, since that leads to
1073 # producing kernels with different security feature characteristics
1074 # depending on the compiler used. (For example, "But I selected
1075 # CC_STACKPROTECTOR_STRONG! Why did it build with _REGULAR?!")
1076 PHONY += prepare-compiler-check
1077 prepare-compiler-check: FORCE
1078 # Make sure compiler supports requested stack protector flag.
1080 ifeq ($(call cc-option, $(stackp-flag)),)
1081 @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1082 $(stackp-flag) not supported by compiler >&2 && exit 1
1085 # Make sure compiler does not have buggy stack-protector support.
1087 ifneq ($(shell $(CONFIG_SHELL) $(stackp-check) $(CC) $(KBUILD_CPPFLAGS) $(biarch)),y)
1088 @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1089 $(stackp-flag) available but compiler is broken >&2 && exit 1
1094 # Generate some files
1095 # ---------------------------------------------------------------------------
1097 # KERNELRELEASE can change from a few different places, meaning version.h
1098 # needs to be updated, so this check is forced on all builds
1101 define filechk_utsrelease.h
1102 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1103 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1106 (echo \#define UTS_RELEASE \"$(KERNELRELEASE)\";)
1109 define filechk_version.h
1110 (echo \#define LINUX_VERSION_CODE $(shell \
1111 expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
1112 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))';)
1115 $(version_h): $(srctree)/Makefile FORCE
1116 $(call filechk,version.h)
1117 $(Q)rm -f $(old_version_h)
1119 include/generated/utsrelease.h: include/config/kernel.release FORCE
1120 $(call filechk,utsrelease.h)
1124 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1125 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1127 # ---------------------------------------------------------------------------
1130 #Default location for installed headers
1131 export INSTALL_HDR_PATH = $(objtree)/usr
1133 # If we do an all arch process set dst to include/arch-$(SRCARCH)
1134 hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(SRCARCH), dst=include)
1136 PHONY += archheaders
1139 PHONY += archscripts
1143 __headers: $(version_h) scripts_basic uapi-asm-generic archheaders archscripts
1144 $(Q)$(MAKE) $(build)=scripts build_unifdef
1146 PHONY += headers_install_all
1147 headers_install_all:
1148 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh install
1150 PHONY += headers_install
1151 headers_install: __headers
1152 $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1153 $(error Headers not exportable for the $(SRCARCH) architecture))
1154 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include
1155 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst)
1157 PHONY += headers_check_all
1158 headers_check_all: headers_install_all
1159 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh check
1161 PHONY += headers_check
1162 headers_check: headers_install
1163 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include HDRCHECK=1
1164 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst) HDRCHECK=1
1166 # ---------------------------------------------------------------------------
1171 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1173 PHONY += kselftest-clean
1175 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests clean
1177 PHONY += kselftest-merge
1179 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1180 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \
1181 -m $(objtree)/.config \
1182 $(srctree)/tools/testing/selftests/*/config
1183 +$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1185 # ---------------------------------------------------------------------------
1188 ifdef CONFIG_MODULES
1190 # By default, build modules as well
1196 # A module can be listed more than once in obj-m resulting in
1197 # duplicate lines in modules.order files. Those are removed
1198 # using awk while concatenating to the final file.
1201 modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
1202 $(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
1203 @$(kecho) ' Building modules, stage 2.';
1204 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1206 modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
1207 $(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
1209 %/modules.builtin: include/config/auto.conf
1210 $(Q)$(MAKE) $(modbuiltin)=$*
1213 # Target to prepare building external modules
1214 PHONY += modules_prepare
1215 modules_prepare: prepare scripts
1217 # Target to install modules
1218 PHONY += modules_install
1219 modules_install: _modinst_ _modinst_post
1223 @rm -rf $(MODLIB)/kernel
1224 @rm -f $(MODLIB)/source
1225 @mkdir -p $(MODLIB)/kernel
1226 @ln -s $(abspath $(srctree)) $(MODLIB)/source
1227 @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
1228 rm -f $(MODLIB)/build ; \
1229 ln -s $(CURDIR) $(MODLIB)/build ; \
1231 @cp -f $(objtree)/modules.order $(MODLIB)/
1232 @cp -f $(objtree)/modules.builtin $(MODLIB)/
1233 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1235 # This depmod is only for convenience to give the initial
1236 # boot a modules.dep even before / is mounted read-write. However the
1237 # boot script depmod is the master version.
1238 PHONY += _modinst_post
1239 _modinst_post: _modinst_
1242 ifeq ($(CONFIG_MODULE_SIG), y)
1243 PHONY += modules_sign
1245 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1248 else # CONFIG_MODULES
1250 # Modules not configured
1251 # ---------------------------------------------------------------------------
1253 PHONY += modules modules_install
1254 modules modules_install:
1256 @echo >&2 "The present kernel configuration has modules disabled."
1257 @echo >&2 "Type 'make config' and enable loadable module support."
1258 @echo >&2 "Then build a kernel with module support enabled."
1262 endif # CONFIG_MODULES
1265 # Cleaning is done on three levels.
1266 # make clean Delete most generated files
1267 # Leave enough to build external modules
1268 # make mrproper Delete the current configuration, and all generated files
1269 # make distclean Remove editor backup files, patch leftover files and the like
1271 # Directories & files removed with 'make clean'
1272 CLEAN_DIRS += $(MODVERDIR)
1274 # Directories & files removed with 'make mrproper'
1275 MRPROPER_DIRS += include/config usr/include include/generated \
1276 arch/*/include/generated .tmp_objdiff
1277 MRPROPER_FILES += .config .config.old .version \
1278 Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
1279 signing_key.pem signing_key.priv signing_key.x509 \
1280 x509.genkey extra_certificates signing_key.x509.keyid \
1281 signing_key.x509.signer vmlinux-gdb.py
1283 # clean - Delete most, but leave enough to build external modules
1285 clean: rm-dirs := $(CLEAN_DIRS)
1286 clean: rm-files := $(CLEAN_FILES)
1287 clean-dirs := $(addprefix _clean_, . $(vmlinux-alldirs) Documentation samples)
1289 PHONY += $(clean-dirs) clean archclean vmlinuxclean
1291 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1294 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1295 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1297 clean: archclean vmlinuxclean
1299 # mrproper - Delete all generated files, including .config
1301 mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS))
1302 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1303 mrproper-dirs := $(addprefix _mrproper_,scripts)
1305 PHONY += $(mrproper-dirs) mrproper archmrproper
1307 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1309 mrproper: clean archmrproper $(mrproper-dirs)
1318 @find $(srctree) $(RCS_FIND_IGNORE) \
1319 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1320 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1321 -o -name 'core' \) \
1322 -type f -print | xargs rm -f
1325 # Packaging of the kernel to various formats
1326 # ---------------------------------------------------------------------------
1327 # rpm target kept for backward compatibility
1328 package-dir := scripts/package
1331 $(Q)$(MAKE) $(build)=$(package-dir) $@
1332 %pkg: include/config/kernel.release FORCE
1333 $(Q)$(MAKE) $(build)=$(package-dir) $@
1334 rpm: include/config/kernel.release FORCE
1335 $(Q)$(MAKE) $(build)=$(package-dir) $@
1338 # Brief documentation of the typical targets used
1339 # ---------------------------------------------------------------------------
1341 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1342 boards := $(sort $(notdir $(boards)))
1343 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1344 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1348 @echo 'Cleaning targets:'
1349 @echo ' clean - Remove most generated files but keep the config and'
1350 @echo ' enough build support to build external modules'
1351 @echo ' mrproper - Remove all generated files + config + various backup files'
1352 @echo ' distclean - mrproper + remove editor backup and patch files'
1354 @echo 'Configuration targets:'
1355 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1357 @echo 'Other generic targets:'
1358 @echo ' all - Build all targets marked with [*]'
1359 @echo '* vmlinux - Build the bare kernel'
1360 @echo '* modules - Build all modules'
1361 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1362 @echo ' dir/ - Build all files in dir and below'
1363 @echo ' dir/file.[ois] - Build specified target only'
1364 @echo ' dir/file.ll - Build the LLVM assembly file'
1365 @echo ' (requires compiler support for LLVM assembly generation)'
1366 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1367 @echo ' (requires a recent binutils and recent build (System.map))'
1368 @echo ' dir/file.ko - Build module including final link'
1369 @echo ' modules_prepare - Set up for building external modules'
1370 @echo ' tags/TAGS - Generate tags file for editors'
1371 @echo ' cscope - Generate cscope index'
1372 @echo ' gtags - Generate GNU GLOBAL index'
1373 @echo ' kernelrelease - Output the release version string (use with make -s)'
1374 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1375 @echo ' image_name - Output the image name (use with make -s)'
1376 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1377 echo ' (default: $(INSTALL_HDR_PATH))'; \
1379 @echo 'Static analysers:'
1380 @echo ' checkstack - Generate a list of stack hogs'
1381 @echo ' namespacecheck - Name space analysis on compiled kernel'
1382 @echo ' versioncheck - Sanity check on version.h usage'
1383 @echo ' includecheck - Check for duplicate included header files'
1384 @echo ' export_report - List the usages of all exported symbols'
1385 @echo ' headers_check - Sanity check on exported headers'
1386 @echo ' headerdep - Detect inclusion cycles in headers'
1387 @$(MAKE) -f $(srctree)/scripts/Makefile.help checker-help
1389 @echo 'Kernel selftest:'
1390 @echo ' kselftest - Build and run kernel selftest (run as root)'
1391 @echo ' Build, install, and boot kernel before'
1392 @echo ' running kselftest on it'
1393 @echo ' kselftest-clean - Remove all generated kselftest files'
1394 @echo ' kselftest-merge - Merge all the config dependencies of kselftest to existed'
1397 @echo 'Userspace tools targets:'
1398 @echo ' use "make tools/help"'
1399 @echo ' or "cd tools; make help"'
1401 @echo 'Kernel packaging:'
1402 @$(MAKE) $(build)=$(package-dir) help
1404 @echo 'Documentation targets:'
1405 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1407 @echo 'Architecture specific targets ($(SRCARCH)):'
1408 @$(if $(archhelp),$(archhelp),\
1409 echo ' No architecture specific help defined for $(SRCARCH)')
1412 $(foreach b, $(boards), \
1413 printf " %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1415 @$(if $(board-dirs), \
1416 $(foreach b, $(board-dirs), \
1417 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1418 printf " %-16s - Show all of the above\\n" help-boards; \
1421 @echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1422 @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
1423 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1424 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK (sparse by default)'
1425 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1426 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1427 @echo ' make W=n [targets] Enable extra gcc checks, n=1,2,3 where'
1428 @echo ' 1: warnings which may be relevant and do not occur too often'
1429 @echo ' 2: warnings which occur quite often but may still be relevant'
1430 @echo ' 3: more obscure warnings, can most likely be ignored'
1431 @echo ' Multiple levels can be combined with W=12 or W=123'
1433 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1434 @echo 'For further info see the ./README file'
1437 help-board-dirs := $(addprefix help-,$(board-dirs))
1439 help-boards: $(help-board-dirs)
1441 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1443 $(help-board-dirs): help-%:
1444 @echo 'Architecture specific targets ($(SRCARCH) $*):'
1445 @$(if $(boards-per-dir), \
1446 $(foreach b, $(boards-per-dir), \
1447 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1451 # Documentation targets
1452 # ---------------------------------------------------------------------------
1453 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs linkcheckdocs
1454 PHONY += $(DOC_TARGETS)
1455 $(DOC_TARGETS): scripts_basic FORCE
1456 $(Q)$(MAKE) $(build)=Documentation $@
1458 else # KBUILD_EXTMOD
1461 # External module support.
1462 # When building external modules the kernel used as basis is considered
1463 # read-only, and no consistency checks are made and the make
1464 # system is not used on the basis kernel. If updates are required
1465 # in the basis kernel ordinary make commands (without M=...) must
1468 # The following are the only valid targets when building external
1470 # make M=dir clean Delete all automatically generated files
1471 # make M=dir modules Make all modules in specified dir
1472 # make M=dir Same as 'make M=dir modules'
1473 # make M=dir modules_install
1474 # Install the modules built in the module directory
1475 # Assumes install directory is already created
1477 # We are always building modules
1479 PHONY += crmodverdir
1483 PHONY += $(objtree)/Module.symvers
1484 $(objtree)/Module.symvers:
1485 @test -e $(objtree)/Module.symvers || ( \
1487 echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1488 echo " is missing; modules will have no dependencies and modversions."; \
1491 module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
1492 PHONY += $(module-dirs) modules
1493 $(module-dirs): crmodverdir $(objtree)/Module.symvers
1494 $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
1496 modules: $(module-dirs)
1497 @$(kecho) ' Building modules, stage 2.';
1498 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1500 PHONY += modules_install
1501 modules_install: _emodinst_ _emodinst_post
1503 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1506 $(Q)mkdir -p $(MODLIB)/$(install-dir)
1507 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1509 PHONY += _emodinst_post
1510 _emodinst_post: _emodinst_
1513 clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))
1515 PHONY += $(clean-dirs) clean
1517 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1519 clean: rm-dirs := $(MODVERDIR)
1520 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1524 @echo ' Building external modules.'
1525 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1527 @echo ' modules - default target, build the module(s)'
1528 @echo ' modules_install - install the module'
1529 @echo ' clean - remove generated files in module directory only'
1533 PHONY += prepare scripts
1536 endif # KBUILD_EXTMOD
1538 clean: $(clean-dirs)
1541 @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1542 \( -name '*.[oas]' -o -name '*.ko' -o -name '.*.cmd' \
1546 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1547 -o -name '*.symtypes' -o -name 'modules.order' \
1548 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1549 -o -name .cache.mk \
1550 -o -name '*.c.[012]*.*' \
1552 -o -name '*.gcno' \) -type f -print | xargs rm -f
1554 # Generate tags for editors
1555 # ---------------------------------------------------------------------------
1556 quiet_cmd_tags = GEN $@
1557 cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
1559 tags TAGS cscope gtags: FORCE
1562 # Scripts to check various things for consistency
1563 # ---------------------------------------------------------------------------
1565 PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1568 find $(srctree)/* $(RCS_FIND_IGNORE) \
1569 -name '*.[hcS]' -type f -print | sort \
1570 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1573 find $(srctree)/* $(RCS_FIND_IGNORE) \
1574 -name '*.[hcS]' -type f -print | sort \
1575 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1578 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1581 $(PERL) $(srctree)/scripts/namespace.pl
1584 $(PERL) $(srctree)/scripts/export_report.pl
1586 endif #ifeq ($(config-targets),1)
1587 endif #ifeq ($(mixed-targets),1)
1589 PHONY += checkstack kernelrelease kernelversion image_name
1591 # UML needs a little special treatment here. It wants to use the host
1592 # toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
1593 # else wants $(ARCH), including people doing cross-builds, which means
1594 # that $(SUBARCH) doesn't work here.
1596 CHECKSTACK_ARCH := $(SUBARCH)
1598 CHECKSTACK_ARCH := $(ARCH)
1601 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1602 $(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1605 @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1608 @echo $(KERNELVERSION)
1611 @echo $(KBUILD_IMAGE)
1613 # Clear a bunch of variables before executing the submake
1615 $(Q)mkdir -p $(objtree)/tools
1616 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/
1619 $(Q)mkdir -p $(objtree)/tools
1620 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/ $*
1623 # ---------------------------------------------------------------------------
1624 # Single targets are compatible with:
1625 # - build with mixed source and output
1626 # - build with separate output dir 'make O=...'
1627 # - external modules
1629 # target-dir => where to store outputfile
1630 # build-dir => directory in kernel source tree to use
1632 ifeq ($(KBUILD_EXTMOD),)
1633 build-dir = $(patsubst %/,%,$(dir $@))
1634 target-dir = $(dir $@)
1636 zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
1637 build-dir = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
1638 target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@))
1641 %.s: %.c prepare scripts FORCE
1642 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1643 %.i: %.c prepare scripts FORCE
1644 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1645 %.o: %.c prepare scripts FORCE
1646 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1647 %.lst: %.c prepare scripts FORCE
1648 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1649 %.s: %.S prepare scripts FORCE
1650 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1651 %.o: %.S prepare scripts FORCE
1652 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1653 %.symtypes: %.c prepare scripts FORCE
1654 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1655 %.ll: %.c prepare scripts FORCE
1656 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1659 /: prepare scripts FORCE
1661 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1662 $(build)=$(build-dir)
1663 # Make sure the latest headers are built for Documentation
1664 Documentation/ samples/: headers_install
1665 %/: prepare scripts FORCE
1667 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1668 $(build)=$(build-dir)
1669 %.ko: prepare scripts FORCE
1671 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1672 $(build)=$(build-dir) $(@:.ko=.o)
1673 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1675 # FIXME Should go into a make.lib or something
1676 # ===========================================================================
1678 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs)))
1679 cmd_rmdirs = rm -rf $(rm-dirs)
1681 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
1682 cmd_rmfiles = rm -f $(rm-files)
1684 # Run depmod only if we have System.map and depmod is executable
1685 quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
1686 cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1687 $(KERNELRELEASE) "$(patsubst y,_,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))"
1689 # Create temporary dir for module support files
1690 # clean it up only when building all modules
1691 cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
1692 $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
1694 # read all saved command lines
1696 targets := $(wildcard $(sort $(targets)))
1697 cmd_files := $(wildcard .*.cmd $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
1699 ifneq ($(cmd_files),)
1700 $(cmd_files): ; # Do not try to update included dependency files
1701 include $(cmd_files)
1704 endif # skip-makefile
1709 # Declare the contents of the .PHONY variable as phony. We keep that
1710 # information in a variable so we can use it in if_changed and friends.