1 # SPDX-License-Identifier: GPL-2.0
9 # To see a list of typical targets execute "make help"
10 # More info can be located in ./README
11 # Comments in this file are targeted only to the developer, do not
12 # expect to learn how to build the kernel reading this file.
14 # o Do not use make's built-in rules and variables
15 # (this increases performance and avoids hard-to-debug behaviour);
16 # o Look for make include files relative to root of kernel src
17 MAKEFLAGS += -rR --include-dir=$(CURDIR)
19 # Avoid funny character set dependencies
23 export LC_COLLATE LC_NUMERIC
25 # Avoid interference with shell env settings
28 # We are using a recursive build, so we need to do a little thinking
29 # to get the ordering right.
31 # Most importantly: sub-Makefiles should only ever modify files in
32 # their own directory. If in some directory we have a dependency on
33 # a file in another dir (which doesn't happen often, but it's often
34 # unavoidable when linking the built-in.o targets which finally
35 # turn into vmlinux), we will call a sub make in that other dir, and
36 # after that we are sure that everything which is in that other dir
39 # The only cases where we need to modify files which have global
40 # effects are thus separated out and done before the recursive
41 # descending is started. They are now explicitly listed as the
45 # ---------------------------------------------------------------------------
47 # Normally, we echo the whole command before executing it. By making
48 # that echo $($(quiet)$(cmd)), we now have the possibility to set
49 # $(quiet) to choose other forms of output instead, e.g.
51 # quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
52 # cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
54 # If $(quiet) is empty, the whole command will be printed.
55 # If it is set to "quiet_", only the short version will be printed.
56 # If it is set to "silent_", nothing will be printed at all, since
57 # the variable $(silent_cmd_cc_o_c) doesn't exist.
59 # A simple variant is to prefix commands with $(Q) - that's useful
60 # for commands that shall be hidden in non-verbose mode.
64 # If KBUILD_VERBOSE equals 0 then the above command will be hidden.
65 # If KBUILD_VERBOSE equals 1 then the above command is displayed.
67 # To put more focus on warnings, be less verbose as default
68 # Use 'make V=1' to see the full commands
70 ifeq ("$(origin V)", "command line")
77 ifeq ($(KBUILD_VERBOSE),1)
85 # If the user is running make -s (silent mode), suppress echoing of
88 ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
93 export quiet Q KBUILD_VERBOSE
95 # kbuild supports saving output files in a separate directory.
96 # To locate output files in a separate directory two syntaxes are supported.
97 # In both cases the working directory must be the root of the kernel src.
99 # Use "make O=dir/to/store/output/files/"
101 # 2) Set KBUILD_OUTPUT
102 # Set the environment variable KBUILD_OUTPUT to point to the directory
103 # where the output files shall be placed.
104 # export KBUILD_OUTPUT=dir/to/store/output/files/
107 # The O= assignment takes precedence over the KBUILD_OUTPUT environment
110 # KBUILD_SRC is not intended to be used by the regular user (for now),
111 # it is set on invocation of make with KBUILD_OUTPUT or O= specified.
112 ifeq ($(KBUILD_SRC),)
114 # OK, Make called in directory where kernel src resides
115 # Do we want to locate output files in a separate directory?
116 ifeq ("$(origin O)", "command line")
117 KBUILD_OUTPUT := $(O)
120 # That's our default target when none is given on the command line
124 # Cancel implicit rules on top Makefile
125 $(CURDIR)/Makefile Makefile: ;
127 ifneq ($(words $(subst :, ,$(CURDIR))), 1)
128 $(error main directory cannot contain spaces nor colons)
131 ifneq ($(KBUILD_OUTPUT),)
132 # check that the output directory actually exists
133 saved-output := $(KBUILD_OUTPUT)
134 KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
136 $(if $(KBUILD_OUTPUT),, \
137 $(error failed to create output directory "$(saved-output)"))
139 PHONY += $(MAKECMDGOALS) sub-make
141 $(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
144 # Invoke a second make in the output directory, passing relevant variables
146 $(Q)$(MAKE) -C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR) \
147 -f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS))
149 # Leave processing to above invocation of make
151 endif # ifneq ($(KBUILD_OUTPUT),)
152 endif # ifeq ($(KBUILD_SRC),)
154 # We process the rest of the Makefile if this is the final invocation of make
155 ifeq ($(skip-makefile),)
157 # Do not print "Entering directory ...",
158 # but we want to display it when entering to the output directory
159 # so that IDEs/editors are able to understand relative filenames.
160 MAKEFLAGS += --no-print-directory
162 # Call a source code checker (by default, "sparse") as part of the
165 # Use 'make C=1' to enable checking of only re-compiled files.
166 # Use 'make C=2' to enable checking of *all* source files, regardless
167 # of whether they are re-compiled or not.
169 # See the file "Documentation/dev-tools/sparse.rst" for more details,
170 # including where to get the "sparse" utility.
172 ifeq ("$(origin C)", "command line")
173 KBUILD_CHECKSRC = $(C)
175 ifndef KBUILD_CHECKSRC
179 # Use make M=dir to specify directory of external module to build
180 # Old syntax make ... SUBDIRS=$PWD is still supported
181 # Setting the environment variable KBUILD_EXTMOD take precedence
183 KBUILD_EXTMOD ?= $(SUBDIRS)
186 ifeq ("$(origin M)", "command line")
187 KBUILD_EXTMOD := $(M)
190 # If building an external module we do not care about the all: rule
191 # but instead _all depend on modules
193 ifeq ($(KBUILD_EXTMOD),)
199 ifeq ($(KBUILD_SRC),)
200 # building in the source tree
203 ifeq ($(KBUILD_SRC)/,$(dir $(CURDIR)))
204 # building in a subdirectory of the source tree
207 srctree := $(KBUILD_SRC)
214 VPATH := $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))
216 export srctree objtree VPATH
218 # SUBARCH tells the usermode build what the underlying arch is. That is set
219 # first, and if a usermode build is happening, the "ARCH=um" on the command
220 # line overrides the setting of ARCH below. If a native build is happening,
221 # then ARCH is assigned, getting whatever value it gets normally, and
222 # SUBARCH is subsequently ignored.
224 SUBARCH := $(shell uname -m | sed -e s/i.86/x86/ -e s/x86_64/x86/ \
225 -e s/sun4u/sparc64/ \
226 -e s/arm.*/arm/ -e s/sa110/arm/ \
227 -e s/s390x/s390/ -e s/parisc64/parisc/ \
228 -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
229 -e s/sh[234].*/sh/ -e s/aarch64.*/arm64/ \
232 # Cross compiling and selecting different set of gcc/bin-utils
233 # ---------------------------------------------------------------------------
235 # When performing cross compilation for other architectures ARCH shall be set
236 # to the target architecture. (See arch/* for the possibilities).
237 # ARCH can be set during invocation of make:
239 # Another way is to have ARCH set in the environment.
240 # The default ARCH is the host where make is executed.
242 # CROSS_COMPILE specify the prefix used for all executables used
243 # during compilation. Only gcc and related bin-utils executables
244 # are prefixed with $(CROSS_COMPILE).
245 # CROSS_COMPILE can be set on the command line
246 # make CROSS_COMPILE=ia64-linux-
247 # Alternatively CROSS_COMPILE can be set in the environment.
248 # A third alternative is to store a setting in .config so that plain
249 # "make" in the configured kernel build directory always uses that.
250 # Default value for CROSS_COMPILE is not to prefix executables
251 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
253 CROSS_COMPILE ?= $(CONFIG_CROSS_COMPILE:"%"=%)
255 # Architecture as present in compile.h
256 UTS_MACHINE := $(ARCH)
259 # Additional ARCH settings for x86
263 ifeq ($(ARCH),x86_64)
267 # Additional ARCH settings for sparc
268 ifeq ($(ARCH),sparc32)
271 ifeq ($(ARCH),sparc64)
275 # Additional ARCH settings for sh
280 # Additional ARCH settings for tile
281 ifeq ($(ARCH),tilepro)
284 ifeq ($(ARCH),tilegx)
288 # Where to locate arch specific headers
289 hdr-arch := $(SRCARCH)
291 KCONFIG_CONFIG ?= .config
292 export KCONFIG_CONFIG
294 # SHELL used by kbuild
295 CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
296 else if [ -x /bin/bash ]; then echo /bin/bash; \
297 else echo sh; fi ; fi)
299 HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS)
300 HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS)
301 HOST_LFS_LIBS := $(shell getconf LFS_LIBS)
305 HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 \
306 -fomit-frame-pointer -std=gnu89 $(HOST_LFS_CFLAGS)
307 HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS)
308 HOSTLDFLAGS := $(HOST_LFS_LDFLAGS)
309 HOST_LOADLIBES := $(HOST_LFS_LIBS)
311 ifeq ($(shell $(HOSTCC) -v 2>&1 | grep -c "clang version"), 1)
312 HOSTCFLAGS += -Wno-unused-value -Wno-unused-parameter \
313 -Wno-missing-field-initializers -fno-delete-null-pointer-checks
316 # Decide whether to build built-in, modular, or both.
317 # Normally, just do built-in.
322 # If we have only "make modules", don't compile built-in objects.
323 # When we're building modules with modversions, we need to consider
324 # the built-in objects during the descend as well, in order to
325 # make sure the checksums are up to date before we record them.
327 ifeq ($(MAKECMDGOALS),modules)
328 KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
331 # If we have "make <whatever> modules", compile modules
332 # in addition to whatever we do anyway.
333 # Just "make" or "make all" shall build modules as well
335 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
339 ifeq ($(MAKECMDGOALS),)
343 export KBUILD_MODULES KBUILD_BUILTIN
344 export KBUILD_CHECKSRC KBUILD_SRC KBUILD_EXTMOD
346 # We need some generic definitions (do not try to remake the file).
347 scripts/Kbuild.include: ;
348 include scripts/Kbuild.include
350 # Make variables (CC, etc...)
351 AS = $(CROSS_COMPILE)as
352 LD = $(CROSS_COMPILE)ld
353 CC = $(CROSS_COMPILE)gcc
355 AR = $(CROSS_COMPILE)ar
356 NM = $(CROSS_COMPILE)nm
357 STRIP = $(CROSS_COMPILE)strip
358 OBJCOPY = $(CROSS_COMPILE)objcopy
359 OBJDUMP = $(CROSS_COMPILE)objdump
361 GENKSYMS = scripts/genksyms/genksyms
362 INSTALLKERNEL := installkernel
363 DEPMOD = /sbin/depmod
368 CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
369 -Wbitwise -Wno-return-void $(CF)
377 CFLAGS_GCOV := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,)
378 CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,)
381 # Use USERINCLUDE when you must reference the UAPI directories only.
383 -I$(srctree)/arch/$(hdr-arch)/include/uapi \
384 -I$(objtree)/arch/$(hdr-arch)/include/generated/uapi \
385 -I$(srctree)/include/uapi \
386 -I$(objtree)/include/generated/uapi \
387 -include $(srctree)/include/linux/kconfig.h
389 # Use LINUXINCLUDE when you must reference the include/ directory.
390 # Needed to be compatible with the O= option
392 -I$(srctree)/arch/$(hdr-arch)/include \
393 -I$(objtree)/arch/$(hdr-arch)/include/generated \
394 $(if $(KBUILD_SRC), -I$(srctree)/include) \
395 -I$(objtree)/include \
398 KBUILD_CPPFLAGS := -D__KERNEL__
400 KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
401 -fno-strict-aliasing -fno-common -fshort-wchar \
402 -Werror-implicit-function-declaration \
403 -Wno-format-security \
404 -std=gnu89 $(call cc-option,-fno-PIE)
407 KBUILD_AFLAGS_KERNEL :=
408 KBUILD_CFLAGS_KERNEL :=
409 KBUILD_AFLAGS := -D__ASSEMBLY__ $(call cc-option,-fno-PIE)
410 KBUILD_AFLAGS_MODULE := -DMODULE
411 KBUILD_CFLAGS_MODULE := -DMODULE
412 KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
414 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
415 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
416 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
418 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
419 export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC
420 export CPP AR NM STRIP OBJCOPY OBJDUMP HOSTLDFLAGS HOST_LOADLIBES
421 export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE
422 export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
424 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
425 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_GCOV CFLAGS_KCOV CFLAGS_KASAN CFLAGS_UBSAN
426 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
427 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
428 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
429 export KBUILD_ARFLAGS
431 # When compiling out-of-tree modules, put MODVERDIR in the module
432 # tree rather than in the kernel tree. The kernel tree might
434 export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
436 # Files to ignore in find ... statements
438 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
439 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
441 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
442 --exclude CVS --exclude .pc --exclude .hg --exclude .git
444 # ===========================================================================
445 # Rules shared between *config targets and build targets
447 # Basic helpers built in scripts/basic/
448 PHONY += scripts_basic
450 $(Q)$(MAKE) $(build)=scripts/basic
451 $(Q)rm -f .tmp_quiet_recordmcount
453 # To avoid any implicit rule to kick in, define an empty command.
454 scripts/basic/%: scripts_basic ;
456 PHONY += outputmakefile
457 # outputmakefile generates a Makefile in the output directory, if using a
458 # separate output directory. This allows convenient use of make in the
461 ifneq ($(KBUILD_SRC),)
462 $(Q)ln -fsn $(srctree) source
463 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile \
464 $(srctree) $(objtree) $(VERSION) $(PATCHLEVEL)
467 # Support for using generic headers in asm-generic
468 PHONY += asm-generic uapi-asm-generic
469 asm-generic: uapi-asm-generic
470 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
471 src=asm obj=arch/$(SRCARCH)/include/generated/asm
473 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
474 src=uapi/asm obj=arch/$(SRCARCH)/include/generated/uapi/asm
476 # To make sure we do not include .config for any of the *config targets
477 # catch them early, and hand them over to scripts/kconfig/Makefile
478 # It is allowed to specify more targets when calling make, including
479 # mixing *config targets and build targets.
480 # For example 'make oldconfig all'.
481 # Detect when mixed targets is specified, and make a second invocation
482 # of make so .config is not included in this case either (for *config).
484 version_h := include/generated/uapi/linux/version.h
485 old_version_h := include/linux/version.h
487 no-dot-config-targets := clean mrproper distclean \
488 cscope gtags TAGS tags help% %docs check% coccicheck \
489 $(version_h) headers_% archheaders archscripts \
490 kernelversion %src-pkg
496 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
497 ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
502 ifeq ($(KBUILD_EXTMOD),)
503 ifneq ($(filter config %config,$(MAKECMDGOALS)),)
505 ifneq ($(words $(MAKECMDGOALS)),1)
510 # install and modules_install need also be processed one by one
511 ifneq ($(filter install,$(MAKECMDGOALS)),)
512 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
517 ifeq ($(mixed-targets),1)
518 # ===========================================================================
519 # We're called with mixed targets (*config and build targets).
520 # Handle them one by one.
522 PHONY += $(MAKECMDGOALS) __build_one_by_one
524 $(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
529 for i in $(MAKECMDGOALS); do \
530 $(MAKE) -f $(srctree)/Makefile $$i; \
534 ifeq ($(config-targets),1)
535 # ===========================================================================
536 # *config targets only - make sure prerequisites are updated, and descend
537 # in scripts/kconfig to make the *config target
539 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
540 # KBUILD_DEFCONFIG may point out an alternative default configuration
541 # used for 'make defconfig'
542 include arch/$(SRCARCH)/Makefile
543 export KBUILD_DEFCONFIG KBUILD_KCONFIG
545 config: scripts_basic outputmakefile FORCE
546 $(Q)$(MAKE) $(build)=scripts/kconfig $@
548 %config: scripts_basic outputmakefile FORCE
549 $(Q)$(MAKE) $(build)=scripts/kconfig $@
552 # ===========================================================================
553 # Build targets only - this includes vmlinux, arch specific targets, clean
554 # targets and others. In general all targets except *config targets.
556 ifeq ($(KBUILD_EXTMOD),)
557 # Additional helpers built in scripts/
558 # Carefully list dependencies so we do not try to build scripts twice
561 scripts: scripts_basic include/config/auto.conf include/config/tristate.conf \
562 asm-generic gcc-plugins
563 $(Q)$(MAKE) $(build)=$(@)
565 # Objects we will link into vmlinux / subdirs we need to visit
567 drivers-y := drivers/ sound/ firmware/
572 endif # KBUILD_EXTMOD
574 ifeq ($(dot-config),1)
576 -include include/config/auto.conf
578 ifeq ($(KBUILD_EXTMOD),)
579 # Read in dependencies to all Kconfig* files, make sure to run
580 # oldconfig if changes are detected.
581 -include include/config/auto.conf.cmd
583 # To avoid any implicit rule to kick in, define an empty command
584 $(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;
586 # If .config is newer than include/config/auto.conf, someone tinkered
587 # with it and forgot to run make oldconfig.
588 # if auto.conf.cmd is missing then we are probably in a cleaned tree so
589 # we execute the config step to be sure to catch updated Kconfig files
590 include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
591 $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig
593 # external modules needs include/generated/autoconf.h and include/config/auto.conf
594 # but do not care if they are up-to-date. Use auto.conf to trigger the test
595 PHONY += include/config/auto.conf
597 include/config/auto.conf:
598 $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
600 echo >&2 " ERROR: Kernel configuration is invalid."; \
601 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
602 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
606 endif # KBUILD_EXTMOD
609 # Dummy target needed, because used as prerequisite
610 include/config/auto.conf: ;
611 endif # $(dot-config)
613 # For the kernel to actually contain only the needed exported symbols,
614 # we have to build modules as well to determine what those symbols are.
615 # (this can be evaluated only once include/config/auto.conf has been included)
616 ifdef CONFIG_TRIM_UNUSED_KSYMS
620 # The all: target is the default when no target is given on the
622 # This allow a user to issue only 'make' to build a kernel including modules
623 # Defaults to vmlinux, but the arch makefile usually adds further targets
626 # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
627 # values of the respective KBUILD_* variables
631 include arch/$(SRCARCH)/Makefile
633 KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
634 KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
635 KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
636 KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
637 KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context)
639 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
640 KBUILD_CFLAGS += $(call cc-option,-Oz,-Os)
641 KBUILD_CFLAGS += $(call cc-disable-warning,maybe-uninitialized,)
643 ifdef CONFIG_PROFILE_ALL_BRANCHES
644 KBUILD_CFLAGS += -O2 $(call cc-disable-warning,maybe-uninitialized,)
650 KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \
651 $(call cc-disable-warning,maybe-uninitialized,))
653 # Tell gcc to never replace conditional load with a non-conditional one
654 KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
656 # check for 'asm goto'
657 ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y)
658 KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
659 KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO
662 include scripts/Makefile.gcc-plugins
664 ifdef CONFIG_READABLE_ASM
665 # Disable optimizations that make assembler listings hard to read.
666 # reorder blocks reorders the control in the function
667 # ipa clone creates specialized cloned functions
668 # partial inlining inlines only parts of functions
669 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
670 $(call cc-option,-fno-ipa-cp-clone,) \
671 $(call cc-option,-fno-partial-inlining)
674 ifneq ($(CONFIG_FRAME_WARN),0)
675 KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
678 # This selects the stack protector compiler flag. Testing it is delayed
679 # until after .config has been reprocessed, in the prepare-compiler-check
681 ifdef CONFIG_CC_STACKPROTECTOR_REGULAR
682 stackp-flag := -fstack-protector
683 stackp-name := REGULAR
685 ifdef CONFIG_CC_STACKPROTECTOR_STRONG
686 stackp-flag := -fstack-protector-strong
687 stackp-name := STRONG
689 # Force off for distro compilers that enable stack protector by default.
690 stackp-flag := $(call cc-option, -fno-stack-protector)
693 # Find arch-specific stack protector compiler sanity-checking script.
694 ifdef CONFIG_CC_STACKPROTECTOR
695 stackp-path := $(srctree)/scripts/gcc-$(SRCARCH)_$(BITS)-has-stack-protector.sh
696 stackp-check := $(wildcard $(stackp-path))
698 KBUILD_CFLAGS += $(stackp-flag)
700 ifeq ($(cc-name),clang)
701 ifneq ($(CROSS_COMPILE),)
702 CLANG_TARGET := --target=$(notdir $(CROSS_COMPILE:%-=%))
703 GCC_TOOLCHAIN := $(realpath $(dir $(shell which $(LD)))/..)
705 ifneq ($(GCC_TOOLCHAIN),)
706 CLANG_GCC_TC := --gcc-toolchain=$(GCC_TOOLCHAIN)
708 KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
709 KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
710 KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
711 KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable)
712 KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
713 KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
714 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
715 # Quiet clang warning: comparison of unsigned expression < 0 is always false
716 KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
717 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
718 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
719 # See modpost pattern 2
720 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
721 KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
722 KBUILD_CFLAGS += $(call cc-option, -no-integrated-as)
723 KBUILD_AFLAGS += $(call cc-option, -no-integrated-as)
726 # These warnings generated too much noise in a regular build.
727 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
728 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
729 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
732 ifdef CONFIG_FRAME_POINTER
733 KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
735 # Some targets (ARM with Thumb2, for example), can't be built with frame
736 # pointers. For those, we don't have FUNCTION_TRACER automatically
737 # select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
738 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
739 # -fomit-frame-pointer with FUNCTION_TRACER.
740 ifndef CONFIG_FUNCTION_TRACER
741 KBUILD_CFLAGS += -fomit-frame-pointer
745 KBUILD_CFLAGS += $(call cc-option, -fno-var-tracking-assignments)
747 ifdef CONFIG_DEBUG_INFO
748 ifdef CONFIG_DEBUG_INFO_SPLIT
749 KBUILD_CFLAGS += $(call cc-option, -gsplit-dwarf, -g)
753 KBUILD_AFLAGS += -Wa,-gdwarf-2
755 ifdef CONFIG_DEBUG_INFO_DWARF4
756 KBUILD_CFLAGS += $(call cc-option, -gdwarf-4,)
759 ifdef CONFIG_DEBUG_INFO_REDUCED
760 KBUILD_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
761 $(call cc-option,-fno-var-tracking)
764 ifdef CONFIG_FUNCTION_TRACER
765 ifndef CC_FLAGS_FTRACE
766 CC_FLAGS_FTRACE := -pg
768 export CC_FLAGS_FTRACE
769 ifdef CONFIG_HAVE_FENTRY
770 CC_USING_FENTRY := $(call cc-option, -mfentry -DCC_USING_FENTRY)
772 KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_USING_FENTRY)
773 KBUILD_AFLAGS += $(CC_USING_FENTRY)
774 ifdef CONFIG_DYNAMIC_FTRACE
775 ifdef CONFIG_HAVE_C_RECORDMCOUNT
776 BUILD_C_RECORDMCOUNT := y
777 export BUILD_C_RECORDMCOUNT
782 # We trigger additional mismatches with less inlining
783 ifdef CONFIG_DEBUG_SECTION_MISMATCH
784 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
787 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
788 KBUILD_CFLAGS += $(call cc-option,-ffunction-sections,)
789 KBUILD_CFLAGS += $(call cc-option,-fdata-sections,)
792 # arch Makefile may override CC so keep this after arch Makefile is included
793 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
794 CHECKFLAGS += $(NOSTDINC_FLAGS)
796 # warn about C99 declaration after statement
797 KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
799 # disable pointer signed / unsigned warnings in gcc 4.0
800 KBUILD_CFLAGS += $(call cc-disable-warning, pointer-sign)
802 # disable invalid "can't wrap" optimizations for signed / pointers
803 KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
805 # conserve stack if available
806 KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
808 # disallow errors like 'EXPORT_GPL(foo);' with missing header
809 KBUILD_CFLAGS += $(call cc-option,-Werror=implicit-int)
811 # require functions to have arguments in prototypes, not empty 'int foo()'
812 KBUILD_CFLAGS += $(call cc-option,-Werror=strict-prototypes)
814 # Prohibit date/time macros, which would make the build non-deterministic
815 KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
817 # enforce correct pointer usage
818 KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
820 # Require designated initializers for all marked structures
821 KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
823 # use the deterministic mode of AR if available
824 KBUILD_ARFLAGS := $(call ar-option,D)
826 include scripts/Makefile.kasan
827 include scripts/Makefile.extrawarn
828 include scripts/Makefile.ubsan
830 # Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
832 KBUILD_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS)
833 KBUILD_AFLAGS += $(ARCH_AFLAGS) $(KAFLAGS)
834 KBUILD_CFLAGS += $(ARCH_CFLAGS) $(KCFLAGS)
836 # Use --build-id when available.
837 LDFLAGS_BUILD_ID := $(patsubst -Wl$(comma)%,%,\
838 $(call cc-ldoption, -Wl$(comma)--build-id,))
839 KBUILD_LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
840 LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
842 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
843 LDFLAGS_vmlinux += $(call ld-option, --gc-sections,)
846 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
847 LDFLAGS_vmlinux += $(call ld-option, -X,)
850 # Default kernel image to build when no specific target is given.
851 # KBUILD_IMAGE may be overruled on the command line or
852 # set in the environment
853 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
855 export KBUILD_IMAGE ?= vmlinux
858 # INSTALL_PATH specifies where to place the updated kernel and system map
859 # images. Default is /boot, but you can set it to other values
860 export INSTALL_PATH ?= /boot
863 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
864 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
865 # an argument if needed. Otherwise it defaults to the kernel install path
867 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
870 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
871 # relocations required by build roots. This is not defined in the
872 # makefile but the argument can be passed to make if needed.
875 MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
879 # INSTALL_MOD_STRIP, if defined, will cause modules to be
880 # stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
881 # the default option --strip-debug will be used. Otherwise,
882 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
884 ifdef INSTALL_MOD_STRIP
885 ifeq ($(INSTALL_MOD_STRIP),1)
886 mod_strip_cmd = $(STRIP) --strip-debug
888 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
889 endif # INSTALL_MOD_STRIP=1
892 endif # INSTALL_MOD_STRIP
895 # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
896 # after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
897 # or CONFIG_MODULE_COMPRESS_XZ.
899 mod_compress_cmd = true
900 ifdef CONFIG_MODULE_COMPRESS
901 ifdef CONFIG_MODULE_COMPRESS_GZIP
902 mod_compress_cmd = gzip -n -f
903 endif # CONFIG_MODULE_COMPRESS_GZIP
904 ifdef CONFIG_MODULE_COMPRESS_XZ
905 mod_compress_cmd = xz -f
906 endif # CONFIG_MODULE_COMPRESS_XZ
907 endif # CONFIG_MODULE_COMPRESS
908 export mod_compress_cmd
910 # Select initial ramdisk compression format, default is gzip(1).
911 # This shall be used by the dracut(8) tool while creating an initramfs image.
913 INITRD_COMPRESS-y := gzip
914 INITRD_COMPRESS-$(CONFIG_RD_BZIP2) := bzip2
915 INITRD_COMPRESS-$(CONFIG_RD_LZMA) := lzma
916 INITRD_COMPRESS-$(CONFIG_RD_XZ) := xz
917 INITRD_COMPRESS-$(CONFIG_RD_LZO) := lzo
918 INITRD_COMPRESS-$(CONFIG_RD_LZ4) := lz4
919 # do not export INITRD_COMPRESS, since we didn't actually
920 # choose a sane default compression above.
921 # export INITRD_COMPRESS := $(INITRD_COMPRESS-y)
923 ifdef CONFIG_MODULE_SIG_ALL
924 $(eval $(call config_filename,MODULE_SIG_KEY))
926 mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
932 ifdef CONFIG_STACK_VALIDATION
933 has_libelf := $(call try-run,\
934 echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0)
935 ifeq ($(has_libelf),1)
936 objtool_target := tools/objtool FORCE
938 ifdef CONFIG_UNWINDER_ORC
939 $(error "Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel")
941 $(warning "Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel")
943 SKIP_STACK_VALIDATION := 1
944 export SKIP_STACK_VALIDATION
949 ifeq ($(KBUILD_EXTMOD),)
950 core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
952 vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
953 $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
954 $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
956 vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
957 $(init-) $(core-) $(drivers-) $(net-) $(libs-) $(virt-))))
959 init-y := $(patsubst %/, %/built-in.o, $(init-y))
960 core-y := $(patsubst %/, %/built-in.o, $(core-y))
961 drivers-y := $(patsubst %/, %/built-in.o, $(drivers-y))
962 net-y := $(patsubst %/, %/built-in.o, $(net-y))
963 libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
964 libs-y2 := $(filter-out %.a, $(patsubst %/, %/built-in.o, $(libs-y)))
965 virt-y := $(patsubst %/, %/built-in.o, $(virt-y))
967 # Externally visible symbols (used by link-vmlinux.sh)
968 export KBUILD_VMLINUX_INIT := $(head-y) $(init-y)
969 export KBUILD_VMLINUX_MAIN := $(core-y) $(libs-y2) $(drivers-y) $(net-y) $(virt-y)
970 export KBUILD_VMLINUX_LIBS := $(libs-y1)
971 export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
972 export LDFLAGS_vmlinux
973 # used by scripts/package/Makefile
974 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools)
976 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_INIT) $(KBUILD_VMLINUX_MAIN) $(KBUILD_VMLINUX_LIBS)
978 # Include targets which we want to execute sequentially if the rest of the
979 # kernel build went well. If CONFIG_TRIM_UNUSED_KSYMS is set, this might be
980 # evaluated more than once.
981 PHONY += vmlinux_prereq
982 vmlinux_prereq: $(vmlinux-deps) FORCE
983 ifdef CONFIG_HEADERS_CHECK
984 $(Q)$(MAKE) -f $(srctree)/Makefile headers_check
986 ifdef CONFIG_GDB_SCRIPTS
987 $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
989 ifdef CONFIG_TRIM_UNUSED_KSYMS
990 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
991 "$(MAKE) -f $(srctree)/Makefile vmlinux"
994 # standalone target for easier testing
995 include/generated/autoksyms.h: FORCE
996 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh true
998 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1000 # Final link of vmlinux with optional arch pass after final link
1001 cmd_link-vmlinux = \
1002 $(CONFIG_SHELL) $< $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) ; \
1003 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1005 vmlinux: scripts/link-vmlinux.sh vmlinux_prereq $(vmlinux-deps) FORCE
1006 +$(call if_changed,link-vmlinux)
1008 # Build samples along the rest of the kernel
1009 ifdef CONFIG_SAMPLES
1010 vmlinux-dirs += samples
1013 # The actual objects are generated when descending,
1014 # make sure no implicit rule kicks in
1015 $(sort $(vmlinux-deps)): $(vmlinux-dirs) ;
1017 # Handle descending into subdirectories listed in $(vmlinux-dirs)
1018 # Preset locale variables to speed up the build process. Limit locale
1019 # tweaks to this spot to avoid wrong language settings when running
1020 # make menuconfig etc.
1021 # Error messages still appears in the original language
1023 PHONY += $(vmlinux-dirs)
1024 $(vmlinux-dirs): prepare scripts
1025 $(Q)$(MAKE) $(build)=$@
1027 define filechk_kernel.release
1028 echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1031 # Store (new) KERNELRELEASE string in include/config/kernel.release
1032 include/config/kernel.release: include/config/auto.conf FORCE
1033 $(call filechk,kernel.release)
1036 # Things we need to do before we recursively start building the kernel
1037 # or the modules are listed in "prepare".
1038 # A multi level approach is used. prepareN is processed before prepareN-1.
1039 # archprepare is used in arch Makefiles and when processed asm symlink,
1040 # version.h and scripts_basic is processed / created.
1042 # Listed in dependency order
1043 PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3
1045 # prepare3 is used to check if we are building in a separate output directory,
1047 # 1) Check that make has not been executed in the kernel src $(srctree)
1048 prepare3: include/config/kernel.release
1049 ifneq ($(KBUILD_SRC),)
1050 @$(kecho) ' Using $(srctree) as source for kernel'
1051 $(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
1052 echo >&2 " $(srctree) is not clean, please run 'make mrproper'"; \
1053 echo >&2 " in the '$(srctree)' directory.";\
1058 # prepare2 creates a makefile if using a separate output directory.
1059 # From this point forward, .config has been reprocessed, so any rules
1060 # that need to depend on updated CONFIG_* values can be checked here.
1061 prepare2: prepare3 prepare-compiler-check outputmakefile asm-generic
1063 prepare1: prepare2 $(version_h) include/generated/utsrelease.h \
1064 include/config/auto.conf
1067 archprepare: archheaders archscripts prepare1 scripts_basic
1069 prepare0: archprepare gcc-plugins
1070 $(Q)$(MAKE) $(build)=.
1072 # All the preparing..
1073 prepare: prepare0 prepare-objtool
1075 PHONY += prepare-objtool
1076 prepare-objtool: $(objtool_target)
1078 # Check for CONFIG flags that require compiler support. Abort the build
1079 # after .config has been processed, but before the kernel build starts.
1081 # For security-sensitive CONFIG options, we don't want to fallback and/or
1082 # silently change which compiler flags will be used, since that leads to
1083 # producing kernels with different security feature characteristics
1084 # depending on the compiler used. (For example, "But I selected
1085 # CC_STACKPROTECTOR_STRONG! Why did it build with _REGULAR?!")
1086 PHONY += prepare-compiler-check
1087 prepare-compiler-check: FORCE
1088 # Make sure compiler supports requested stack protector flag.
1090 ifeq ($(call cc-option, $(stackp-flag)),)
1091 @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1092 $(stackp-flag) not supported by compiler >&2 && exit 1
1095 # Make sure compiler does not have buggy stack-protector support.
1097 ifneq ($(shell $(CONFIG_SHELL) $(stackp-check) $(CC) $(KBUILD_CPPFLAGS) $(biarch)),y)
1098 @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1099 $(stackp-flag) available but compiler is broken >&2 && exit 1
1104 # Generate some files
1105 # ---------------------------------------------------------------------------
1107 # KERNELRELEASE can change from a few different places, meaning version.h
1108 # needs to be updated, so this check is forced on all builds
1111 define filechk_utsrelease.h
1112 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1113 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1116 (echo \#define UTS_RELEASE \"$(KERNELRELEASE)\";)
1119 define filechk_version.h
1120 (echo \#define LINUX_VERSION_CODE $(shell \
1121 expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
1122 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))';)
1125 $(version_h): $(srctree)/Makefile FORCE
1126 $(call filechk,version.h)
1127 $(Q)rm -f $(old_version_h)
1129 include/generated/utsrelease.h: include/config/kernel.release FORCE
1130 $(call filechk,utsrelease.h)
1134 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1135 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1137 # ---------------------------------------------------------------------------
1140 #Default location for installed headers
1141 export INSTALL_HDR_PATH = $(objtree)/usr
1143 # If we do an all arch process set dst to include/arch-$(hdr-arch)
1144 hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(hdr-arch), dst=include)
1146 PHONY += archheaders
1149 PHONY += archscripts
1153 __headers: $(version_h) scripts_basic uapi-asm-generic archheaders archscripts
1154 $(Q)$(MAKE) $(build)=scripts build_unifdef
1156 PHONY += headers_install_all
1157 headers_install_all:
1158 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh install
1160 PHONY += headers_install
1161 headers_install: __headers
1162 $(if $(wildcard $(srctree)/arch/$(hdr-arch)/include/uapi/asm/Kbuild),, \
1163 $(error Headers not exportable for the $(SRCARCH) architecture))
1164 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include
1165 $(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/uapi $(hdr-dst)
1167 PHONY += headers_check_all
1168 headers_check_all: headers_install_all
1169 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh check
1171 PHONY += headers_check
1172 headers_check: headers_install
1173 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include HDRCHECK=1
1174 $(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/uapi $(hdr-dst) HDRCHECK=1
1176 # ---------------------------------------------------------------------------
1181 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1183 PHONY += kselftest-clean
1185 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests clean
1187 PHONY += kselftest-merge
1189 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1190 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \
1191 -m $(objtree)/.config \
1192 $(srctree)/tools/testing/selftests/*/config
1193 +$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1195 # ---------------------------------------------------------------------------
1198 ifdef CONFIG_MODULES
1200 # By default, build modules as well
1206 # A module can be listed more than once in obj-m resulting in
1207 # duplicate lines in modules.order files. Those are removed
1208 # using awk while concatenating to the final file.
1211 modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
1212 $(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
1213 @$(kecho) ' Building modules, stage 2.';
1214 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1216 modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
1217 $(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
1219 %/modules.builtin: include/config/auto.conf
1220 $(Q)$(MAKE) $(modbuiltin)=$*
1223 # Target to prepare building external modules
1224 PHONY += modules_prepare
1225 modules_prepare: prepare scripts
1227 # Target to install modules
1228 PHONY += modules_install
1229 modules_install: _modinst_ _modinst_post
1233 @rm -rf $(MODLIB)/kernel
1234 @rm -f $(MODLIB)/source
1235 @mkdir -p $(MODLIB)/kernel
1236 @ln -s $(abspath $(srctree)) $(MODLIB)/source
1237 @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
1238 rm -f $(MODLIB)/build ; \
1239 ln -s $(CURDIR) $(MODLIB)/build ; \
1241 @cp -f $(objtree)/modules.order $(MODLIB)/
1242 @cp -f $(objtree)/modules.builtin $(MODLIB)/
1243 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1245 # This depmod is only for convenience to give the initial
1246 # boot a modules.dep even before / is mounted read-write. However the
1247 # boot script depmod is the master version.
1248 PHONY += _modinst_post
1249 _modinst_post: _modinst_
1252 ifeq ($(CONFIG_MODULE_SIG), y)
1253 PHONY += modules_sign
1255 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1258 else # CONFIG_MODULES
1260 # Modules not configured
1261 # ---------------------------------------------------------------------------
1263 PHONY += modules modules_install
1264 modules modules_install:
1266 @echo >&2 "The present kernel configuration has modules disabled."
1267 @echo >&2 "Type 'make config' and enable loadable module support."
1268 @echo >&2 "Then build a kernel with module support enabled."
1272 endif # CONFIG_MODULES
1275 # Cleaning is done on three levels.
1276 # make clean Delete most generated files
1277 # Leave enough to build external modules
1278 # make mrproper Delete the current configuration, and all generated files
1279 # make distclean Remove editor backup files, patch leftover files and the like
1281 # Directories & files removed with 'make clean'
1282 CLEAN_DIRS += $(MODVERDIR)
1284 # Directories & files removed with 'make mrproper'
1285 MRPROPER_DIRS += include/config usr/include include/generated \
1286 arch/*/include/generated .tmp_objdiff
1287 MRPROPER_FILES += .config .config.old .version .old_version \
1288 Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
1289 signing_key.pem signing_key.priv signing_key.x509 \
1290 x509.genkey extra_certificates signing_key.x509.keyid \
1291 signing_key.x509.signer vmlinux-gdb.py
1293 # clean - Delete most, but leave enough to build external modules
1295 clean: rm-dirs := $(CLEAN_DIRS)
1296 clean: rm-files := $(CLEAN_FILES)
1297 clean-dirs := $(addprefix _clean_, . $(vmlinux-alldirs) Documentation samples)
1299 PHONY += $(clean-dirs) clean archclean vmlinuxclean
1301 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1304 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1305 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1307 clean: archclean vmlinuxclean
1309 # mrproper - Delete all generated files, including .config
1311 mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS))
1312 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1313 mrproper-dirs := $(addprefix _mrproper_,scripts)
1315 PHONY += $(mrproper-dirs) mrproper archmrproper
1317 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1319 mrproper: clean archmrproper $(mrproper-dirs)
1328 @find $(srctree) $(RCS_FIND_IGNORE) \
1329 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1330 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1331 -o -name 'core' \) \
1332 -type f -print | xargs rm -f
1335 # Packaging of the kernel to various formats
1336 # ---------------------------------------------------------------------------
1337 # rpm target kept for backward compatibility
1338 package-dir := scripts/package
1341 $(Q)$(MAKE) $(build)=$(package-dir) $@
1342 %pkg: include/config/kernel.release FORCE
1343 $(Q)$(MAKE) $(build)=$(package-dir) $@
1344 rpm: include/config/kernel.release FORCE
1345 $(Q)$(MAKE) $(build)=$(package-dir) $@
1348 # Brief documentation of the typical targets used
1349 # ---------------------------------------------------------------------------
1351 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1352 boards := $(sort $(notdir $(boards)))
1353 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1354 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1358 @echo 'Cleaning targets:'
1359 @echo ' clean - Remove most generated files but keep the config and'
1360 @echo ' enough build support to build external modules'
1361 @echo ' mrproper - Remove all generated files + config + various backup files'
1362 @echo ' distclean - mrproper + remove editor backup and patch files'
1364 @echo 'Configuration targets:'
1365 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1367 @echo 'Other generic targets:'
1368 @echo ' all - Build all targets marked with [*]'
1369 @echo '* vmlinux - Build the bare kernel'
1370 @echo '* modules - Build all modules'
1371 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1372 @echo ' dir/ - Build all files in dir and below'
1373 @echo ' dir/file.[ois] - Build specified target only'
1374 @echo ' dir/file.ll - Build the LLVM assembly file'
1375 @echo ' (requires compiler support for LLVM assembly generation)'
1376 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1377 @echo ' (requires a recent binutils and recent build (System.map))'
1378 @echo ' dir/file.ko - Build module including final link'
1379 @echo ' modules_prepare - Set up for building external modules'
1380 @echo ' tags/TAGS - Generate tags file for editors'
1381 @echo ' cscope - Generate cscope index'
1382 @echo ' gtags - Generate GNU GLOBAL index'
1383 @echo ' kernelrelease - Output the release version string (use with make -s)'
1384 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1385 @echo ' image_name - Output the image name (use with make -s)'
1386 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1387 echo ' (default: $(INSTALL_HDR_PATH))'; \
1389 @echo 'Static analysers:'
1390 @echo ' checkstack - Generate a list of stack hogs'
1391 @echo ' namespacecheck - Name space analysis on compiled kernel'
1392 @echo ' versioncheck - Sanity check on version.h usage'
1393 @echo ' includecheck - Check for duplicate included header files'
1394 @echo ' export_report - List the usages of all exported symbols'
1395 @echo ' headers_check - Sanity check on exported headers'
1396 @echo ' headerdep - Detect inclusion cycles in headers'
1397 @$(MAKE) -f $(srctree)/scripts/Makefile.help checker-help
1399 @echo 'Kernel selftest:'
1400 @echo ' kselftest - Build and run kernel selftest (run as root)'
1401 @echo ' Build, install, and boot kernel before'
1402 @echo ' running kselftest on it'
1403 @echo ' kselftest-clean - Remove all generated kselftest files'
1404 @echo ' kselftest-merge - Merge all the config dependencies of kselftest to existing'
1407 @echo 'Userspace tools targets:'
1408 @echo ' use "make tools/help"'
1409 @echo ' or "cd tools; make help"'
1411 @echo 'Kernel packaging:'
1412 @$(MAKE) $(build)=$(package-dir) help
1414 @echo 'Documentation targets:'
1415 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1417 @echo 'Architecture specific targets ($(SRCARCH)):'
1418 @$(if $(archhelp),$(archhelp),\
1419 echo ' No architecture specific help defined for $(SRCARCH)')
1422 $(foreach b, $(boards), \
1423 printf " %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1425 @$(if $(board-dirs), \
1426 $(foreach b, $(board-dirs), \
1427 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1428 printf " %-16s - Show all of the above\\n" help-boards; \
1431 @echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1432 @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
1433 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1434 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK (sparse by default)'
1435 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1436 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1437 @echo ' make W=n [targets] Enable extra gcc checks, n=1,2,3 where'
1438 @echo ' 1: warnings which may be relevant and do not occur too often'
1439 @echo ' 2: warnings which occur quite often but may still be relevant'
1440 @echo ' 3: more obscure warnings, can most likely be ignored'
1441 @echo ' Multiple levels can be combined with W=12 or W=123'
1443 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1444 @echo 'For further info see the ./README file'
1447 help-board-dirs := $(addprefix help-,$(board-dirs))
1449 help-boards: $(help-board-dirs)
1451 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1453 $(help-board-dirs): help-%:
1454 @echo 'Architecture specific targets ($(SRCARCH) $*):'
1455 @$(if $(boards-per-dir), \
1456 $(foreach b, $(boards-per-dir), \
1457 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1461 # Documentation targets
1462 # ---------------------------------------------------------------------------
1463 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1464 linkcheckdocs dochelp refcheckdocs
1465 PHONY += $(DOC_TARGETS)
1466 $(DOC_TARGETS): scripts_basic FORCE
1467 $(Q)$(MAKE) $(build)=Documentation $@
1469 else # KBUILD_EXTMOD
1472 # External module support.
1473 # When building external modules the kernel used as basis is considered
1474 # read-only, and no consistency checks are made and the make
1475 # system is not used on the basis kernel. If updates are required
1476 # in the basis kernel ordinary make commands (without M=...) must
1479 # The following are the only valid targets when building external
1481 # make M=dir clean Delete all automatically generated files
1482 # make M=dir modules Make all modules in specified dir
1483 # make M=dir Same as 'make M=dir modules'
1484 # make M=dir modules_install
1485 # Install the modules built in the module directory
1486 # Assumes install directory is already created
1488 # We are always building modules
1490 PHONY += crmodverdir
1494 PHONY += $(objtree)/Module.symvers
1495 $(objtree)/Module.symvers:
1496 @test -e $(objtree)/Module.symvers || ( \
1498 echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1499 echo " is missing; modules will have no dependencies and modversions."; \
1502 module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
1503 PHONY += $(module-dirs) modules
1504 $(module-dirs): crmodverdir $(objtree)/Module.symvers
1505 $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
1507 modules: $(module-dirs)
1508 @$(kecho) ' Building modules, stage 2.';
1509 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1511 PHONY += modules_install
1512 modules_install: _emodinst_ _emodinst_post
1514 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1517 $(Q)mkdir -p $(MODLIB)/$(install-dir)
1518 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1520 PHONY += _emodinst_post
1521 _emodinst_post: _emodinst_
1524 clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))
1526 PHONY += $(clean-dirs) clean
1528 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1530 clean: rm-dirs := $(MODVERDIR)
1531 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1535 @echo ' Building external modules.'
1536 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1538 @echo ' modules - default target, build the module(s)'
1539 @echo ' modules_install - install the module'
1540 @echo ' clean - remove generated files in module directory only'
1544 PHONY += prepare scripts
1547 endif # KBUILD_EXTMOD
1549 clean: $(clean-dirs)
1552 @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1553 \( -name '*.[oas]' -o -name '*.ko' -o -name '.*.cmd' \
1554 -o -name '*.ko.*' -o -name '*.dtb' -o -name '*.dtb.S' \
1557 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1558 -o -name '*.symtypes' -o -name 'modules.order' \
1559 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1560 -o -name '*.c.[012]*.*' \
1562 -o -name '*.gcno' \) -type f -print | xargs rm -f
1564 # Generate tags for editors
1565 # ---------------------------------------------------------------------------
1566 quiet_cmd_tags = GEN $@
1567 cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
1569 tags TAGS cscope gtags: FORCE
1572 # Scripts to check various things for consistency
1573 # ---------------------------------------------------------------------------
1575 PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1578 find $(srctree)/* $(RCS_FIND_IGNORE) \
1579 -name '*.[hcS]' -type f -print | sort \
1580 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1583 find $(srctree)/* $(RCS_FIND_IGNORE) \
1584 -name '*.[hcS]' -type f -print | sort \
1585 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1588 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1591 $(PERL) $(srctree)/scripts/namespace.pl
1594 $(PERL) $(srctree)/scripts/export_report.pl
1596 endif #ifeq ($(config-targets),1)
1597 endif #ifeq ($(mixed-targets),1)
1599 PHONY += checkstack kernelrelease kernelversion image_name
1601 # UML needs a little special treatment here. It wants to use the host
1602 # toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
1603 # else wants $(ARCH), including people doing cross-builds, which means
1604 # that $(SUBARCH) doesn't work here.
1606 CHECKSTACK_ARCH := $(SUBARCH)
1608 CHECKSTACK_ARCH := $(ARCH)
1611 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1612 $(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1615 @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1618 @echo $(KERNELVERSION)
1621 @echo $(KBUILD_IMAGE)
1623 # Clear a bunch of variables before executing the submake
1625 $(Q)mkdir -p $(objtree)/tools
1626 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/
1629 $(Q)mkdir -p $(objtree)/tools
1630 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/ $*
1633 # ---------------------------------------------------------------------------
1634 # Single targets are compatible with:
1635 # - build with mixed source and output
1636 # - build with separate output dir 'make O=...'
1637 # - external modules
1639 # target-dir => where to store outputfile
1640 # build-dir => directory in kernel source tree to use
1642 ifeq ($(KBUILD_EXTMOD),)
1643 build-dir = $(patsubst %/,%,$(dir $@))
1644 target-dir = $(dir $@)
1646 zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
1647 build-dir = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
1648 target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@))
1651 %.s: %.c prepare scripts FORCE
1652 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1653 %.i: %.c prepare scripts FORCE
1654 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1655 %.o: %.c prepare scripts FORCE
1656 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1657 %.lst: %.c prepare scripts FORCE
1658 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1659 %.s: %.S prepare scripts FORCE
1660 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1661 %.o: %.S prepare scripts FORCE
1662 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1663 %.symtypes: %.c prepare scripts FORCE
1664 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1665 %.ll: %.c prepare scripts FORCE
1666 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1669 /: prepare scripts FORCE
1671 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1672 $(build)=$(build-dir)
1673 # Make sure the latest headers are built for Documentation
1674 Documentation/ samples/: headers_install
1675 %/: prepare scripts FORCE
1677 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1678 $(build)=$(build-dir)
1679 %.ko: prepare scripts FORCE
1681 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1682 $(build)=$(build-dir) $(@:.ko=.o)
1683 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1685 # FIXME Should go into a make.lib or something
1686 # ===========================================================================
1688 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs)))
1689 cmd_rmdirs = rm -rf $(rm-dirs)
1691 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
1692 cmd_rmfiles = rm -f $(rm-files)
1694 # Run depmod only if we have System.map and depmod is executable
1695 quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
1696 cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1697 $(KERNELRELEASE) "$(patsubst y,_,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))"
1699 # Create temporary dir for module support files
1700 # clean it up only when building all modules
1701 cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
1702 $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
1704 # read all saved command lines
1706 targets := $(wildcard $(sort $(targets)))
1707 cmd_files := $(wildcard .*.cmd $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
1709 ifneq ($(cmd_files),)
1710 $(cmd_files): ; # Do not try to update included dependency files
1711 include $(cmd_files)
1714 endif # skip-makefile
1719 # Declare the contents of the .PHONY variable as phony. We keep that
1720 # information in a variable so we can use it in if_changed and friends.