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 $(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 := $(M)
189 # If building an external module we do not care about the all: rule
190 # but instead _all depend on modules
192 ifeq ($(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)
297 HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS)
298 HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS)
299 HOST_LFS_LIBS := $(shell getconf LFS_LIBS)
303 HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 \
304 -fomit-frame-pointer -std=gnu89 $(HOST_LFS_CFLAGS)
305 HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS)
306 HOSTLDFLAGS := $(HOST_LFS_LDFLAGS)
307 HOST_LOADLIBES := $(HOST_LFS_LIBS)
309 ifeq ($(shell $(HOSTCC) -v 2>&1 | grep -c "clang version"), 1)
310 HOSTCFLAGS += -Wno-unused-value -Wno-unused-parameter \
311 -Wno-missing-field-initializers -fno-delete-null-pointer-checks
314 # Decide whether to build built-in, modular, or both.
315 # Normally, just do built-in.
320 # If we have only "make modules", don't compile built-in objects.
321 # When we're building modules with modversions, we need to consider
322 # the built-in objects during the descend as well, in order to
323 # make sure the checksums are up to date before we record them.
325 ifeq ($(MAKECMDGOALS),modules)
326 KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
329 # If we have "make <whatever> modules", compile modules
330 # in addition to whatever we do anyway.
331 # Just "make" or "make all" shall build modules as well
333 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
337 ifeq ($(MAKECMDGOALS),)
341 export KBUILD_MODULES KBUILD_BUILTIN
342 export KBUILD_CHECKSRC KBUILD_SRC KBUILD_EXTMOD
344 # We need some generic definitions (do not try to remake the file).
345 scripts/Kbuild.include: ;
346 include scripts/Kbuild.include
348 # Make variables (CC, etc...)
349 AS = $(CROSS_COMPILE)as
350 LD = $(CROSS_COMPILE)ld
351 CC = $(CROSS_COMPILE)gcc
353 AR = $(CROSS_COMPILE)ar
354 NM = $(CROSS_COMPILE)nm
355 STRIP = $(CROSS_COMPILE)strip
356 OBJCOPY = $(CROSS_COMPILE)objcopy
357 OBJDUMP = $(CROSS_COMPILE)objdump
359 GENKSYMS = scripts/genksyms/genksyms
360 INSTALLKERNEL := installkernel
361 DEPMOD = /sbin/depmod
366 CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
367 -Wbitwise -Wno-return-void $(CF)
375 CFLAGS_GCOV := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,)
376 CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,)
379 # Use USERINCLUDE when you must reference the UAPI directories only.
381 -I$(srctree)/arch/$(hdr-arch)/include/uapi \
382 -I$(objtree)/arch/$(hdr-arch)/include/generated/uapi \
383 -I$(srctree)/include/uapi \
384 -I$(objtree)/include/generated/uapi \
385 -include $(srctree)/include/linux/kconfig.h
387 # Use LINUXINCLUDE when you must reference the include/ directory.
388 # Needed to be compatible with the O= option
390 -I$(srctree)/arch/$(hdr-arch)/include \
391 -I$(objtree)/arch/$(hdr-arch)/include/generated \
392 $(if $(KBUILD_SRC), -I$(srctree)/include) \
393 -I$(objtree)/include \
396 KBUILD_CPPFLAGS := -D__KERNEL__
398 KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
399 -fno-strict-aliasing -fno-common -fshort-wchar \
400 -Werror-implicit-function-declaration \
401 -Wno-format-security \
402 -std=gnu89 $(call cc-option,-fno-PIE)
405 KBUILD_AFLAGS_KERNEL :=
406 KBUILD_CFLAGS_KERNEL :=
407 KBUILD_AFLAGS := -D__ASSEMBLY__ $(call cc-option,-fno-PIE)
408 KBUILD_AFLAGS_MODULE := -DMODULE
409 KBUILD_CFLAGS_MODULE := -DMODULE
410 KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
412 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
413 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
414 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
416 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
417 export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC
418 export CPP AR NM STRIP OBJCOPY OBJDUMP HOSTLDFLAGS HOST_LOADLIBES
419 export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE
420 export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
422 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
423 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_GCOV CFLAGS_KCOV CFLAGS_KASAN CFLAGS_UBSAN
424 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
425 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
426 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
427 export KBUILD_ARFLAGS
429 # When compiling out-of-tree modules, put MODVERDIR in the module
430 # tree rather than in the kernel tree. The kernel tree might
432 export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
434 # Files to ignore in find ... statements
436 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
437 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
439 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
440 --exclude CVS --exclude .pc --exclude .hg --exclude .git
442 # ===========================================================================
443 # Rules shared between *config targets and build targets
445 # Basic helpers built in scripts/basic/
446 PHONY += scripts_basic
448 $(Q)$(MAKE) $(build)=scripts/basic
449 $(Q)rm -f .tmp_quiet_recordmcount
451 # To avoid any implicit rule to kick in, define an empty command.
452 scripts/basic/%: scripts_basic ;
454 PHONY += outputmakefile
455 # outputmakefile generates a Makefile in the output directory, if using a
456 # separate output directory. This allows convenient use of make in the
459 ifneq ($(KBUILD_SRC),)
460 $(Q)ln -fsn $(srctree) source
461 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile \
462 $(srctree) $(objtree) $(VERSION) $(PATCHLEVEL)
465 # Support for using generic headers in asm-generic
466 PHONY += asm-generic uapi-asm-generic
467 asm-generic: uapi-asm-generic
468 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
469 src=asm obj=arch/$(SRCARCH)/include/generated/asm
471 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
472 src=uapi/asm obj=arch/$(SRCARCH)/include/generated/uapi/asm
474 # To make sure we do not include .config for any of the *config targets
475 # catch them early, and hand them over to scripts/kconfig/Makefile
476 # It is allowed to specify more targets when calling make, including
477 # mixing *config targets and build targets.
478 # For example 'make oldconfig all'.
479 # Detect when mixed targets is specified, and make a second invocation
480 # of make so .config is not included in this case either (for *config).
482 version_h := include/generated/uapi/linux/version.h
483 old_version_h := include/linux/version.h
485 no-dot-config-targets := clean mrproper distclean \
486 cscope gtags TAGS tags help% %docs check% coccicheck \
487 $(version_h) headers_% archheaders archscripts \
488 kernelversion %src-pkg
494 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
495 ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
500 ifeq ($(KBUILD_EXTMOD),)
501 ifneq ($(filter config %config,$(MAKECMDGOALS)),)
503 ifneq ($(words $(MAKECMDGOALS)),1)
508 # install and modules_install need also be processed one by one
509 ifneq ($(filter install,$(MAKECMDGOALS)),)
510 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
515 ifeq ($(mixed-targets),1)
516 # ===========================================================================
517 # We're called with mixed targets (*config and build targets).
518 # Handle them one by one.
520 PHONY += $(MAKECMDGOALS) __build_one_by_one
522 $(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
527 for i in $(MAKECMDGOALS); do \
528 $(MAKE) -f $(srctree)/Makefile $$i; \
532 ifeq ($(config-targets),1)
533 # ===========================================================================
534 # *config targets only - make sure prerequisites are updated, and descend
535 # in scripts/kconfig to make the *config target
537 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
538 # KBUILD_DEFCONFIG may point out an alternative default configuration
539 # used for 'make defconfig'
540 include arch/$(SRCARCH)/Makefile
541 export KBUILD_DEFCONFIG KBUILD_KCONFIG
543 config: scripts_basic outputmakefile FORCE
544 $(Q)$(MAKE) $(build)=scripts/kconfig $@
546 %config: scripts_basic outputmakefile FORCE
547 $(Q)$(MAKE) $(build)=scripts/kconfig $@
550 # ===========================================================================
551 # Build targets only - this includes vmlinux, arch specific targets, clean
552 # targets and others. In general all targets except *config targets.
554 ifeq ($(KBUILD_EXTMOD),)
555 # Additional helpers built in scripts/
556 # Carefully list dependencies so we do not try to build scripts twice
559 scripts: scripts_basic include/config/auto.conf include/config/tristate.conf \
560 asm-generic gcc-plugins
561 $(Q)$(MAKE) $(build)=$(@)
563 # Objects we will link into vmlinux / subdirs we need to visit
565 drivers-y := drivers/ sound/ firmware/
570 endif # KBUILD_EXTMOD
572 ifeq ($(dot-config),1)
574 -include include/config/auto.conf
576 ifeq ($(KBUILD_EXTMOD),)
577 # Read in dependencies to all Kconfig* files, make sure to run
578 # oldconfig if changes are detected.
579 -include include/config/auto.conf.cmd
581 # To avoid any implicit rule to kick in, define an empty command
582 $(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;
584 # If .config is newer than include/config/auto.conf, someone tinkered
585 # with it and forgot to run make oldconfig.
586 # if auto.conf.cmd is missing then we are probably in a cleaned tree so
587 # we execute the config step to be sure to catch updated Kconfig files
588 include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
589 $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig
591 # external modules needs include/generated/autoconf.h and include/config/auto.conf
592 # but do not care if they are up-to-date. Use auto.conf to trigger the test
593 PHONY += include/config/auto.conf
595 include/config/auto.conf:
596 $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
598 echo >&2 " ERROR: Kernel configuration is invalid."; \
599 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
600 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
604 endif # KBUILD_EXTMOD
607 # Dummy target needed, because used as prerequisite
608 include/config/auto.conf: ;
609 endif # $(dot-config)
611 # For the kernel to actually contain only the needed exported symbols,
612 # we have to build modules as well to determine what those symbols are.
613 # (this can be evaluated only once include/config/auto.conf has been included)
614 ifdef CONFIG_TRIM_UNUSED_KSYMS
618 # The all: target is the default when no target is given on the
620 # This allow a user to issue only 'make' to build a kernel including modules
621 # Defaults to vmlinux, but the arch makefile usually adds further targets
624 # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
625 # values of the respective KBUILD_* variables
629 include arch/$(SRCARCH)/Makefile
631 KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
632 KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
633 KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
634 KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
635 KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context)
637 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
638 KBUILD_CFLAGS += $(call cc-option,-Oz,-Os)
639 KBUILD_CFLAGS += $(call cc-disable-warning,maybe-uninitialized,)
641 ifdef CONFIG_PROFILE_ALL_BRANCHES
642 KBUILD_CFLAGS += -O2 $(call cc-disable-warning,maybe-uninitialized,)
648 KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \
649 $(call cc-disable-warning,maybe-uninitialized,))
651 # Tell gcc to never replace conditional load with a non-conditional one
652 KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
654 # check for 'asm goto'
655 ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y)
656 KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
657 KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO
660 include scripts/Makefile.gcc-plugins
662 ifdef CONFIG_READABLE_ASM
663 # Disable optimizations that make assembler listings hard to read.
664 # reorder blocks reorders the control in the function
665 # ipa clone creates specialized cloned functions
666 # partial inlining inlines only parts of functions
667 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
668 $(call cc-option,-fno-ipa-cp-clone,) \
669 $(call cc-option,-fno-partial-inlining)
672 ifneq ($(CONFIG_FRAME_WARN),0)
673 KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
676 # This selects the stack protector compiler flag. Testing it is delayed
677 # until after .config has been reprocessed, in the prepare-compiler-check
679 ifdef CONFIG_CC_STACKPROTECTOR_REGULAR
680 stackp-flag := -fstack-protector
681 stackp-name := REGULAR
683 ifdef CONFIG_CC_STACKPROTECTOR_STRONG
684 stackp-flag := -fstack-protector-strong
685 stackp-name := STRONG
687 # Force off for distro compilers that enable stack protector by default.
688 stackp-flag := $(call cc-option, -fno-stack-protector)
691 # Find arch-specific stack protector compiler sanity-checking script.
692 ifdef CONFIG_CC_STACKPROTECTOR
693 stackp-path := $(srctree)/scripts/gcc-$(SRCARCH)_$(BITS)-has-stack-protector.sh
694 stackp-check := $(wildcard $(stackp-path))
696 KBUILD_CFLAGS += $(stackp-flag)
698 ifeq ($(cc-name),clang)
699 ifneq ($(CROSS_COMPILE),)
700 CLANG_TARGET := -target $(notdir $(CROSS_COMPILE:%-=%))
701 GCC_TOOLCHAIN := $(realpath $(dir $(shell which $(LD)))/..)
703 ifneq ($(GCC_TOOLCHAIN),)
704 CLANG_GCC_TC := -gcc-toolchain $(GCC_TOOLCHAIN)
706 KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
707 KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
708 KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
709 KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable)
710 KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
711 KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
712 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
713 # Quiet clang warning: comparison of unsigned expression < 0 is always false
714 KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
715 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
716 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
717 # See modpost pattern 2
718 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
719 KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
720 KBUILD_CFLAGS += $(call cc-option, -no-integrated-as)
721 KBUILD_AFLAGS += $(call cc-option, -no-integrated-as)
724 # These warnings generated too much noise in a regular build.
725 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
726 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
727 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
730 ifdef CONFIG_FRAME_POINTER
731 KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
733 # Some targets (ARM with Thumb2, for example), can't be built with frame
734 # pointers. For those, we don't have FUNCTION_TRACER automatically
735 # select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
736 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
737 # -fomit-frame-pointer with FUNCTION_TRACER.
738 ifndef CONFIG_FUNCTION_TRACER
739 KBUILD_CFLAGS += -fomit-frame-pointer
743 KBUILD_CFLAGS += $(call cc-option, -fno-var-tracking-assignments)
745 ifdef CONFIG_DEBUG_INFO
746 ifdef CONFIG_DEBUG_INFO_SPLIT
747 KBUILD_CFLAGS += $(call cc-option, -gsplit-dwarf, -g)
751 KBUILD_AFLAGS += -Wa,-gdwarf-2
753 ifdef CONFIG_DEBUG_INFO_DWARF4
754 KBUILD_CFLAGS += $(call cc-option, -gdwarf-4,)
757 ifdef CONFIG_DEBUG_INFO_REDUCED
758 KBUILD_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
759 $(call cc-option,-fno-var-tracking)
762 ifdef CONFIG_FUNCTION_TRACER
763 ifndef CC_FLAGS_FTRACE
764 CC_FLAGS_FTRACE := -pg
766 export CC_FLAGS_FTRACE
767 ifdef CONFIG_HAVE_FENTRY
768 CC_USING_FENTRY := $(call cc-option, -mfentry -DCC_USING_FENTRY)
770 KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_USING_FENTRY)
771 KBUILD_AFLAGS += $(CC_USING_FENTRY)
772 ifdef CONFIG_DYNAMIC_FTRACE
773 ifdef CONFIG_HAVE_C_RECORDMCOUNT
774 BUILD_C_RECORDMCOUNT := y
775 export BUILD_C_RECORDMCOUNT
780 # We trigger additional mismatches with less inlining
781 ifdef CONFIG_DEBUG_SECTION_MISMATCH
782 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
785 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
786 KBUILD_CFLAGS += $(call cc-option,-ffunction-sections,)
787 KBUILD_CFLAGS += $(call cc-option,-fdata-sections,)
790 # arch Makefile may override CC so keep this after arch Makefile is included
791 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
792 CHECKFLAGS += $(NOSTDINC_FLAGS)
794 # warn about C99 declaration after statement
795 KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
797 # disable pointer signed / unsigned warnings in gcc 4.0
798 KBUILD_CFLAGS += $(call cc-disable-warning, pointer-sign)
800 # disable invalid "can't wrap" optimizations for signed / pointers
801 KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
803 # conserve stack if available
804 KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
806 # disallow errors like 'EXPORT_GPL(foo);' with missing header
807 KBUILD_CFLAGS += $(call cc-option,-Werror=implicit-int)
809 # require functions to have arguments in prototypes, not empty 'int foo()'
810 KBUILD_CFLAGS += $(call cc-option,-Werror=strict-prototypes)
812 # Prohibit date/time macros, which would make the build non-deterministic
813 KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
815 # enforce correct pointer usage
816 KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
818 # Require designated initializers for all marked structures
819 KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
821 # use the deterministic mode of AR if available
822 KBUILD_ARFLAGS := $(call ar-option,D)
824 include scripts/Makefile.kasan
825 include scripts/Makefile.extrawarn
826 include scripts/Makefile.ubsan
828 # Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
830 KBUILD_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS)
831 KBUILD_AFLAGS += $(ARCH_AFLAGS) $(KAFLAGS)
832 KBUILD_CFLAGS += $(ARCH_CFLAGS) $(KCFLAGS)
834 # Use --build-id when available.
835 LDFLAGS_BUILD_ID := $(patsubst -Wl$(comma)%,%,\
836 $(call cc-ldoption, -Wl$(comma)--build-id,))
837 KBUILD_LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
838 LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
840 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
841 LDFLAGS_vmlinux += $(call ld-option, --gc-sections,)
844 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
845 LDFLAGS_vmlinux += $(call ld-option, -X,)
848 # Default kernel image to build when no specific target is given.
849 # KBUILD_IMAGE may be overruled on the command line or
850 # set in the environment
851 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
853 export KBUILD_IMAGE ?= vmlinux
856 # INSTALL_PATH specifies where to place the updated kernel and system map
857 # images. Default is /boot, but you can set it to other values
858 export INSTALL_PATH ?= /boot
861 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
862 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
863 # an argument if needed. Otherwise it defaults to the kernel install path
865 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
868 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
869 # relocations required by build roots. This is not defined in the
870 # makefile but the argument can be passed to make if needed.
873 MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
877 # INSTALL_MOD_STRIP, if defined, will cause modules to be
878 # stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
879 # the default option --strip-debug will be used. Otherwise,
880 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
882 ifdef INSTALL_MOD_STRIP
883 ifeq ($(INSTALL_MOD_STRIP),1)
884 mod_strip_cmd = $(STRIP) --strip-debug
886 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
887 endif # INSTALL_MOD_STRIP=1
890 endif # INSTALL_MOD_STRIP
893 # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
894 # after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
895 # or CONFIG_MODULE_COMPRESS_XZ.
897 mod_compress_cmd = true
898 ifdef CONFIG_MODULE_COMPRESS
899 ifdef CONFIG_MODULE_COMPRESS_GZIP
900 mod_compress_cmd = gzip -n -f
901 endif # CONFIG_MODULE_COMPRESS_GZIP
902 ifdef CONFIG_MODULE_COMPRESS_XZ
903 mod_compress_cmd = xz -f
904 endif # CONFIG_MODULE_COMPRESS_XZ
905 endif # CONFIG_MODULE_COMPRESS
906 export mod_compress_cmd
908 # Select initial ramdisk compression format, default is gzip(1).
909 # This shall be used by the dracut(8) tool while creating an initramfs image.
911 INITRD_COMPRESS-y := gzip
912 INITRD_COMPRESS-$(CONFIG_RD_BZIP2) := bzip2
913 INITRD_COMPRESS-$(CONFIG_RD_LZMA) := lzma
914 INITRD_COMPRESS-$(CONFIG_RD_XZ) := xz
915 INITRD_COMPRESS-$(CONFIG_RD_LZO) := lzo
916 INITRD_COMPRESS-$(CONFIG_RD_LZ4) := lz4
917 # do not export INITRD_COMPRESS, since we didn't actually
918 # choose a sane default compression above.
919 # export INITRD_COMPRESS := $(INITRD_COMPRESS-y)
921 ifdef CONFIG_MODULE_SIG_ALL
922 $(eval $(call config_filename,MODULE_SIG_KEY))
924 mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
930 ifdef CONFIG_STACK_VALIDATION
931 has_libelf := $(call try-run,\
932 echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0)
933 ifeq ($(has_libelf),1)
934 objtool_target := tools/objtool FORCE
936 ifdef CONFIG_ORC_UNWINDER
937 $(error "Cannot generate ORC metadata for CONFIG_ORC_UNWINDER=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel")
939 $(warning "Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel")
941 SKIP_STACK_VALIDATION := 1
942 export SKIP_STACK_VALIDATION
947 ifeq ($(KBUILD_EXTMOD),)
948 core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
950 vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
951 $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
952 $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
954 vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
955 $(init-) $(core-) $(drivers-) $(net-) $(libs-) $(virt-))))
957 init-y := $(patsubst %/, %/built-in.o, $(init-y))
958 core-y := $(patsubst %/, %/built-in.o, $(core-y))
959 drivers-y := $(patsubst %/, %/built-in.o, $(drivers-y))
960 net-y := $(patsubst %/, %/built-in.o, $(net-y))
961 libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
962 libs-y2 := $(filter-out %.a, $(patsubst %/, %/built-in.o, $(libs-y)))
963 virt-y := $(patsubst %/, %/built-in.o, $(virt-y))
965 # Externally visible symbols (used by link-vmlinux.sh)
966 export KBUILD_VMLINUX_INIT := $(head-y) $(init-y)
967 export KBUILD_VMLINUX_MAIN := $(core-y) $(libs-y2) $(drivers-y) $(net-y) $(virt-y)
968 export KBUILD_VMLINUX_LIBS := $(libs-y1)
969 export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
970 export LDFLAGS_vmlinux
971 # used by scripts/package/Makefile
972 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools)
974 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_INIT) $(KBUILD_VMLINUX_MAIN) $(KBUILD_VMLINUX_LIBS)
976 # Include targets which we want to execute sequentially if the rest of the
977 # kernel build went well. If CONFIG_TRIM_UNUSED_KSYMS is set, this might be
978 # evaluated more than once.
979 PHONY += vmlinux_prereq
980 vmlinux_prereq: $(vmlinux-deps) FORCE
981 ifdef CONFIG_HEADERS_CHECK
982 $(Q)$(MAKE) -f $(srctree)/Makefile headers_check
984 ifdef CONFIG_GDB_SCRIPTS
985 $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
987 ifdef CONFIG_TRIM_UNUSED_KSYMS
988 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
989 "$(MAKE) -f $(srctree)/Makefile vmlinux"
992 # standalone target for easier testing
993 include/generated/autoksyms.h: FORCE
994 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh true
996 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
998 # Final link of vmlinux with optional arch pass after final link
1000 $(CONFIG_SHELL) $< $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) ; \
1001 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1003 vmlinux: scripts/link-vmlinux.sh vmlinux_prereq $(vmlinux-deps) FORCE
1004 +$(call if_changed,link-vmlinux)
1006 # Build samples along the rest of the kernel
1007 ifdef CONFIG_SAMPLES
1008 vmlinux-dirs += samples
1011 # The actual objects are generated when descending,
1012 # make sure no implicit rule kicks in
1013 $(sort $(vmlinux-deps)): $(vmlinux-dirs) ;
1015 # Handle descending into subdirectories listed in $(vmlinux-dirs)
1016 # Preset locale variables to speed up the build process. Limit locale
1017 # tweaks to this spot to avoid wrong language settings when running
1018 # make menuconfig etc.
1019 # Error messages still appears in the original language
1021 PHONY += $(vmlinux-dirs)
1022 $(vmlinux-dirs): prepare scripts
1023 $(Q)$(MAKE) $(build)=$@
1025 define filechk_kernel.release
1026 echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1029 # Store (new) KERNELRELEASE string in include/config/kernel.release
1030 include/config/kernel.release: include/config/auto.conf FORCE
1031 $(call filechk,kernel.release)
1034 # Things we need to do before we recursively start building the kernel
1035 # or the modules are listed in "prepare".
1036 # A multi level approach is used. prepareN is processed before prepareN-1.
1037 # archprepare is used in arch Makefiles and when processed asm symlink,
1038 # version.h and scripts_basic is processed / created.
1040 # Listed in dependency order
1041 PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3
1043 # prepare3 is used to check if we are building in a separate output directory,
1045 # 1) Check that make has not been executed in the kernel src $(srctree)
1046 prepare3: include/config/kernel.release
1047 ifneq ($(KBUILD_SRC),)
1048 @$(kecho) ' Using $(srctree) as source for kernel'
1049 $(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
1050 echo >&2 " $(srctree) is not clean, please run 'make mrproper'"; \
1051 echo >&2 " in the '$(srctree)' directory.";\
1056 # prepare2 creates a makefile if using a separate output directory.
1057 # From this point forward, .config has been reprocessed, so any rules
1058 # that need to depend on updated CONFIG_* values can be checked here.
1059 prepare2: prepare3 prepare-compiler-check outputmakefile asm-generic
1061 prepare1: prepare2 $(version_h) include/generated/utsrelease.h \
1062 include/config/auto.conf
1065 archprepare: archheaders archscripts prepare1 scripts_basic
1067 prepare0: archprepare gcc-plugins
1068 $(Q)$(MAKE) $(build)=.
1070 # All the preparing..
1071 prepare: prepare0 prepare-objtool
1073 PHONY += prepare-objtool
1074 prepare-objtool: $(objtool_target)
1076 # Check for CONFIG flags that require compiler support. Abort the build
1077 # after .config has been processed, but before the kernel build starts.
1079 # For security-sensitive CONFIG options, we don't want to fallback and/or
1080 # silently change which compiler flags will be used, since that leads to
1081 # producing kernels with different security feature characteristics
1082 # depending on the compiler used. (For example, "But I selected
1083 # CC_STACKPROTECTOR_STRONG! Why did it build with _REGULAR?!")
1084 PHONY += prepare-compiler-check
1085 prepare-compiler-check: FORCE
1086 # Make sure compiler supports requested stack protector flag.
1088 ifeq ($(call cc-option, $(stackp-flag)),)
1089 @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1090 $(stackp-flag) not supported by compiler >&2 && exit 1
1093 # Make sure compiler does not have buggy stack-protector support.
1095 ifneq ($(shell $(CONFIG_SHELL) $(stackp-check) $(CC) $(KBUILD_CPPFLAGS) $(biarch)),y)
1096 @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1097 $(stackp-flag) available but compiler is broken >&2 && exit 1
1102 # Generate some files
1103 # ---------------------------------------------------------------------------
1105 # KERNELRELEASE can change from a few different places, meaning version.h
1106 # needs to be updated, so this check is forced on all builds
1109 define filechk_utsrelease.h
1110 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1111 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1114 (echo \#define UTS_RELEASE \"$(KERNELRELEASE)\";)
1117 define filechk_version.h
1118 (echo \#define LINUX_VERSION_CODE $(shell \
1119 expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
1120 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))';)
1123 $(version_h): $(srctree)/Makefile FORCE
1124 $(call filechk,version.h)
1125 $(Q)rm -f $(old_version_h)
1127 include/generated/utsrelease.h: include/config/kernel.release FORCE
1128 $(call filechk,utsrelease.h)
1132 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1133 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1135 # ---------------------------------------------------------------------------
1138 #Default location for installed headers
1139 export INSTALL_HDR_PATH = $(objtree)/usr
1141 # If we do an all arch process set dst to include/arch-$(hdr-arch)
1142 hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(hdr-arch), dst=include)
1144 PHONY += archheaders
1147 PHONY += archscripts
1151 __headers: $(version_h) scripts_basic uapi-asm-generic archheaders archscripts
1152 $(Q)$(MAKE) $(build)=scripts build_unifdef
1154 PHONY += headers_install_all
1155 headers_install_all:
1156 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh install
1158 PHONY += headers_install
1159 headers_install: __headers
1160 $(if $(wildcard $(srctree)/arch/$(hdr-arch)/include/uapi/asm/Kbuild),, \
1161 $(error Headers not exportable for the $(SRCARCH) architecture))
1162 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include
1163 $(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/uapi $(hdr-dst)
1165 PHONY += headers_check_all
1166 headers_check_all: headers_install_all
1167 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh check
1169 PHONY += headers_check
1170 headers_check: headers_install
1171 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include HDRCHECK=1
1172 $(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/uapi $(hdr-dst) HDRCHECK=1
1174 # ---------------------------------------------------------------------------
1179 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1181 PHONY += kselftest-clean
1183 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests clean
1185 PHONY += kselftest-merge
1187 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1188 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \
1189 -m $(objtree)/.config \
1190 $(srctree)/tools/testing/selftests/*/config
1191 +$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1193 # ---------------------------------------------------------------------------
1196 ifdef CONFIG_MODULES
1198 # By default, build modules as well
1204 # A module can be listed more than once in obj-m resulting in
1205 # duplicate lines in modules.order files. Those are removed
1206 # using awk while concatenating to the final file.
1209 modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
1210 $(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
1211 @$(kecho) ' Building modules, stage 2.';
1212 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1214 modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
1215 $(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
1217 %/modules.builtin: include/config/auto.conf
1218 $(Q)$(MAKE) $(modbuiltin)=$*
1221 # Target to prepare building external modules
1222 PHONY += modules_prepare
1223 modules_prepare: prepare scripts
1225 # Target to install modules
1226 PHONY += modules_install
1227 modules_install: _modinst_ _modinst_post
1231 @rm -rf $(MODLIB)/kernel
1232 @rm -f $(MODLIB)/source
1233 @mkdir -p $(MODLIB)/kernel
1234 @ln -s $(abspath $(srctree)) $(MODLIB)/source
1235 @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
1236 rm -f $(MODLIB)/build ; \
1237 ln -s $(CURDIR) $(MODLIB)/build ; \
1239 @cp -f $(objtree)/modules.order $(MODLIB)/
1240 @cp -f $(objtree)/modules.builtin $(MODLIB)/
1241 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1243 # This depmod is only for convenience to give the initial
1244 # boot a modules.dep even before / is mounted read-write. However the
1245 # boot script depmod is the master version.
1246 PHONY += _modinst_post
1247 _modinst_post: _modinst_
1250 ifeq ($(CONFIG_MODULE_SIG), y)
1251 PHONY += modules_sign
1253 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1256 else # CONFIG_MODULES
1258 # Modules not configured
1259 # ---------------------------------------------------------------------------
1261 PHONY += modules modules_install
1262 modules modules_install:
1264 @echo >&2 "The present kernel configuration has modules disabled."
1265 @echo >&2 "Type 'make config' and enable loadable module support."
1266 @echo >&2 "Then build a kernel with module support enabled."
1270 endif # CONFIG_MODULES
1273 # Cleaning is done on three levels.
1274 # make clean Delete most generated files
1275 # Leave enough to build external modules
1276 # make mrproper Delete the current configuration, and all generated files
1277 # make distclean Remove editor backup files, patch leftover files and the like
1279 # Directories & files removed with 'make clean'
1280 CLEAN_DIRS += $(MODVERDIR)
1282 # Directories & files removed with 'make mrproper'
1283 MRPROPER_DIRS += include/config usr/include include/generated \
1284 arch/*/include/generated .tmp_objdiff
1285 MRPROPER_FILES += .config .config.old .version .old_version \
1286 Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
1287 signing_key.pem signing_key.priv signing_key.x509 \
1288 x509.genkey extra_certificates signing_key.x509.keyid \
1289 signing_key.x509.signer vmlinux-gdb.py
1291 # clean - Delete most, but leave enough to build external modules
1293 clean: rm-dirs := $(CLEAN_DIRS)
1294 clean: rm-files := $(CLEAN_FILES)
1295 clean-dirs := $(addprefix _clean_, . $(vmlinux-alldirs) Documentation samples)
1297 PHONY += $(clean-dirs) clean archclean vmlinuxclean
1299 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1302 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1303 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1305 clean: archclean vmlinuxclean
1307 # mrproper - Delete all generated files, including .config
1309 mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS))
1310 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1311 mrproper-dirs := $(addprefix _mrproper_,scripts)
1313 PHONY += $(mrproper-dirs) mrproper archmrproper
1315 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1317 mrproper: clean archmrproper $(mrproper-dirs)
1326 @find $(srctree) $(RCS_FIND_IGNORE) \
1327 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1328 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1329 -o -name 'core' \) \
1330 -type f -print | xargs rm -f
1333 # Packaging of the kernel to various formats
1334 # ---------------------------------------------------------------------------
1335 # rpm target kept for backward compatibility
1336 package-dir := scripts/package
1339 $(Q)$(MAKE) $(build)=$(package-dir) $@
1340 %pkg: include/config/kernel.release FORCE
1341 $(Q)$(MAKE) $(build)=$(package-dir) $@
1342 rpm: include/config/kernel.release FORCE
1343 $(Q)$(MAKE) $(build)=$(package-dir) $@
1346 # Brief documentation of the typical targets used
1347 # ---------------------------------------------------------------------------
1349 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1350 boards := $(sort $(notdir $(boards)))
1351 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1352 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1356 @echo 'Cleaning targets:'
1357 @echo ' clean - Remove most generated files but keep the config and'
1358 @echo ' enough build support to build external modules'
1359 @echo ' mrproper - Remove all generated files + config + various backup files'
1360 @echo ' distclean - mrproper + remove editor backup and patch files'
1362 @echo 'Configuration targets:'
1363 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1365 @echo 'Other generic targets:'
1366 @echo ' all - Build all targets marked with [*]'
1367 @echo '* vmlinux - Build the bare kernel'
1368 @echo '* modules - Build all modules'
1369 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1370 @echo ' dir/ - Build all files in dir and below'
1371 @echo ' dir/file.[ois] - Build specified target only'
1372 @echo ' dir/file.ll - Build the LLVM assembly file'
1373 @echo ' (requires compiler support for LLVM assembly generation)'
1374 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1375 @echo ' (requires a recent binutils and recent build (System.map))'
1376 @echo ' dir/file.ko - Build module including final link'
1377 @echo ' modules_prepare - Set up for building external modules'
1378 @echo ' tags/TAGS - Generate tags file for editors'
1379 @echo ' cscope - Generate cscope index'
1380 @echo ' gtags - Generate GNU GLOBAL index'
1381 @echo ' kernelrelease - Output the release version string (use with make -s)'
1382 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1383 @echo ' image_name - Output the image name (use with make -s)'
1384 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1385 echo ' (default: $(INSTALL_HDR_PATH))'; \
1387 @echo 'Static analysers:'
1388 @echo ' checkstack - Generate a list of stack hogs'
1389 @echo ' namespacecheck - Name space analysis on compiled kernel'
1390 @echo ' versioncheck - Sanity check on version.h usage'
1391 @echo ' includecheck - Check for duplicate included header files'
1392 @echo ' export_report - List the usages of all exported symbols'
1393 @echo ' headers_check - Sanity check on exported headers'
1394 @echo ' headerdep - Detect inclusion cycles in headers'
1395 @$(MAKE) -f $(srctree)/scripts/Makefile.help checker-help
1397 @echo 'Kernel selftest:'
1398 @echo ' kselftest - Build and run kernel selftest (run as root)'
1399 @echo ' Build, install, and boot kernel before'
1400 @echo ' running kselftest on it'
1401 @echo ' kselftest-clean - Remove all generated kselftest files'
1402 @echo ' kselftest-merge - Merge all the config dependencies of kselftest to existed'
1405 @echo 'Userspace tools targets:'
1406 @echo ' use "make tools/help"'
1407 @echo ' or "cd tools; make help"'
1409 @echo 'Kernel packaging:'
1410 @$(MAKE) $(build)=$(package-dir) help
1412 @echo 'Documentation targets:'
1413 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1415 @echo 'Architecture specific targets ($(SRCARCH)):'
1416 @$(if $(archhelp),$(archhelp),\
1417 echo ' No architecture specific help defined for $(SRCARCH)')
1420 $(foreach b, $(boards), \
1421 printf " %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1423 @$(if $(board-dirs), \
1424 $(foreach b, $(board-dirs), \
1425 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1426 printf " %-16s - Show all of the above\\n" help-boards; \
1429 @echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1430 @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
1431 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1432 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK (sparse by default)'
1433 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1434 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1435 @echo ' make W=n [targets] Enable extra gcc checks, n=1,2,3 where'
1436 @echo ' 1: warnings which may be relevant and do not occur too often'
1437 @echo ' 2: warnings which occur quite often but may still be relevant'
1438 @echo ' 3: more obscure warnings, can most likely be ignored'
1439 @echo ' Multiple levels can be combined with W=12 or W=123'
1441 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1442 @echo 'For further info see the ./README file'
1445 help-board-dirs := $(addprefix help-,$(board-dirs))
1447 help-boards: $(help-board-dirs)
1449 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1451 $(help-board-dirs): help-%:
1452 @echo 'Architecture specific targets ($(SRCARCH) $*):'
1453 @$(if $(boards-per-dir), \
1454 $(foreach b, $(boards-per-dir), \
1455 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1459 # Documentation targets
1460 # ---------------------------------------------------------------------------
1461 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs linkcheckdocs
1462 PHONY += $(DOC_TARGETS)
1463 $(DOC_TARGETS): scripts_basic FORCE
1464 $(Q)$(MAKE) $(build)=Documentation $@
1466 else # KBUILD_EXTMOD
1469 # External module support.
1470 # When building external modules the kernel used as basis is considered
1471 # read-only, and no consistency checks are made and the make
1472 # system is not used on the basis kernel. If updates are required
1473 # in the basis kernel ordinary make commands (without M=...) must
1476 # The following are the only valid targets when building external
1478 # make M=dir clean Delete all automatically generated files
1479 # make M=dir modules Make all modules in specified dir
1480 # make M=dir Same as 'make M=dir modules'
1481 # make M=dir modules_install
1482 # Install the modules built in the module directory
1483 # Assumes install directory is already created
1485 # We are always building modules
1487 PHONY += crmodverdir
1491 PHONY += $(objtree)/Module.symvers
1492 $(objtree)/Module.symvers:
1493 @test -e $(objtree)/Module.symvers || ( \
1495 echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1496 echo " is missing; modules will have no dependencies and modversions."; \
1499 module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
1500 PHONY += $(module-dirs) modules
1501 $(module-dirs): crmodverdir $(objtree)/Module.symvers
1502 $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
1504 modules: $(module-dirs)
1505 @$(kecho) ' Building modules, stage 2.';
1506 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1508 PHONY += modules_install
1509 modules_install: _emodinst_ _emodinst_post
1511 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1514 $(Q)mkdir -p $(MODLIB)/$(install-dir)
1515 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1517 PHONY += _emodinst_post
1518 _emodinst_post: _emodinst_
1521 clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))
1523 PHONY += $(clean-dirs) clean
1525 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1527 clean: rm-dirs := $(MODVERDIR)
1528 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1532 @echo ' Building external modules.'
1533 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1535 @echo ' modules - default target, build the module(s)'
1536 @echo ' modules_install - install the module'
1537 @echo ' clean - remove generated files in module directory only'
1541 PHONY += prepare scripts
1544 endif # KBUILD_EXTMOD
1546 clean: $(clean-dirs)
1549 @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1550 \( -name '*.[oas]' -o -name '*.ko' -o -name '.*.cmd' \
1554 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1555 -o -name '*.symtypes' -o -name 'modules.order' \
1556 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1557 -o -name '*.c.[012]*.*' \
1559 -o -name '*.gcno' \) -type f -print | xargs rm -f
1561 # Generate tags for editors
1562 # ---------------------------------------------------------------------------
1563 quiet_cmd_tags = GEN $@
1564 cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
1566 tags TAGS cscope gtags: FORCE
1569 # Scripts to check various things for consistency
1570 # ---------------------------------------------------------------------------
1572 PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1575 find $(srctree)/* $(RCS_FIND_IGNORE) \
1576 -name '*.[hcS]' -type f -print | sort \
1577 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1580 find $(srctree)/* $(RCS_FIND_IGNORE) \
1581 -name '*.[hcS]' -type f -print | sort \
1582 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1585 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1588 $(PERL) $(srctree)/scripts/namespace.pl
1591 $(PERL) $(srctree)/scripts/export_report.pl
1593 endif #ifeq ($(config-targets),1)
1594 endif #ifeq ($(mixed-targets),1)
1596 PHONY += checkstack kernelrelease kernelversion image_name
1598 # UML needs a little special treatment here. It wants to use the host
1599 # toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
1600 # else wants $(ARCH), including people doing cross-builds, which means
1601 # that $(SUBARCH) doesn't work here.
1603 CHECKSTACK_ARCH := $(SUBARCH)
1605 CHECKSTACK_ARCH := $(ARCH)
1608 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1609 $(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1612 @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1615 @echo $(KERNELVERSION)
1618 @echo $(KBUILD_IMAGE)
1620 # Clear a bunch of variables before executing the submake
1622 $(Q)mkdir -p $(objtree)/tools
1623 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/
1626 $(Q)mkdir -p $(objtree)/tools
1627 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/ $*
1630 # ---------------------------------------------------------------------------
1631 # Single targets are compatible with:
1632 # - build with mixed source and output
1633 # - build with separate output dir 'make O=...'
1634 # - external modules
1636 # target-dir => where to store outputfile
1637 # build-dir => directory in kernel source tree to use
1639 ifeq ($(KBUILD_EXTMOD),)
1640 build-dir = $(patsubst %/,%,$(dir $@))
1641 target-dir = $(dir $@)
1643 zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
1644 build-dir = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
1645 target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@))
1648 %.s: %.c prepare scripts FORCE
1649 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1650 %.i: %.c prepare scripts FORCE
1651 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1652 %.o: %.c prepare scripts FORCE
1653 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1654 %.lst: %.c prepare scripts FORCE
1655 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1656 %.s: %.S prepare scripts FORCE
1657 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1658 %.o: %.S prepare scripts FORCE
1659 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1660 %.symtypes: %.c prepare scripts FORCE
1661 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1662 %.ll: %.c prepare scripts FORCE
1663 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1666 /: prepare scripts FORCE
1668 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1669 $(build)=$(build-dir)
1670 # Make sure the latest headers are built for Documentation
1671 Documentation/ samples/: headers_install
1672 %/: prepare scripts FORCE
1674 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1675 $(build)=$(build-dir)
1676 %.ko: prepare scripts FORCE
1678 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1679 $(build)=$(build-dir) $(@:.ko=.o)
1680 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1682 # FIXME Should go into a make.lib or something
1683 # ===========================================================================
1685 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs)))
1686 cmd_rmdirs = rm -rf $(rm-dirs)
1688 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
1689 cmd_rmfiles = rm -f $(rm-files)
1691 # Run depmod only if we have System.map and depmod is executable
1692 quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
1693 cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1694 $(KERNELRELEASE) "$(patsubst y,_,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))"
1696 # Create temporary dir for module support files
1697 # clean it up only when building all modules
1698 cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
1699 $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
1701 # read all saved command lines
1703 targets := $(wildcard $(sort $(targets)))
1704 cmd_files := $(wildcard .*.cmd $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
1706 ifneq ($(cmd_files),)
1707 $(cmd_files): ; # Do not try to update included dependency files
1708 include $(cmd_files)
1711 endif # skip-makefile
1716 # Declare the contents of the .PHONY variable as phony. We keep that
1717 # information in a variable so we can use it in if_changed and friends.