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/ )
231 # Cross compiling and selecting different set of gcc/bin-utils
232 # ---------------------------------------------------------------------------
234 # When performing cross compilation for other architectures ARCH shall be set
235 # to the target architecture. (See arch/* for the possibilities).
236 # ARCH can be set during invocation of make:
238 # Another way is to have ARCH set in the environment.
239 # The default ARCH is the host where make is executed.
241 # CROSS_COMPILE specify the prefix used for all executables used
242 # during compilation. Only gcc and related bin-utils executables
243 # are prefixed with $(CROSS_COMPILE).
244 # CROSS_COMPILE can be set on the command line
245 # make CROSS_COMPILE=ia64-linux-
246 # Alternatively CROSS_COMPILE can be set in the environment.
247 # A third alternative is to store a setting in .config so that plain
248 # "make" in the configured kernel build directory always uses that.
249 # Default value for CROSS_COMPILE is not to prefix executables
250 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
252 CROSS_COMPILE ?= $(CONFIG_CROSS_COMPILE:"%"=%)
254 # Architecture as present in compile.h
255 UTS_MACHINE := $(ARCH)
258 # Additional ARCH settings for x86
262 ifeq ($(ARCH),x86_64)
266 # Additional ARCH settings for sparc
267 ifeq ($(ARCH),sparc32)
270 ifeq ($(ARCH),sparc64)
274 # Additional ARCH settings for sh
279 # Additional ARCH settings for tile
280 ifeq ($(ARCH),tilepro)
283 ifeq ($(ARCH),tilegx)
287 # Where to locate arch specific headers
288 hdr-arch := $(SRCARCH)
290 KCONFIG_CONFIG ?= .config
291 export KCONFIG_CONFIG
293 # SHELL used by kbuild
294 CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
295 else if [ -x /bin/bash ]; then echo /bin/bash; \
296 else echo sh; fi ; fi)
298 HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS)
299 HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS)
300 HOST_LFS_LIBS := $(shell getconf LFS_LIBS)
304 HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 \
305 -fomit-frame-pointer -std=gnu89 $(HOST_LFS_CFLAGS)
306 HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS)
307 HOSTLDFLAGS := $(HOST_LFS_LDFLAGS)
308 HOST_LOADLIBES := $(HOST_LFS_LIBS)
310 ifeq ($(shell $(HOSTCC) -v 2>&1 | grep -c "clang version"), 1)
311 HOSTCFLAGS += -Wno-unused-value -Wno-unused-parameter \
312 -Wno-missing-field-initializers -fno-delete-null-pointer-checks
315 # Decide whether to build built-in, modular, or both.
316 # Normally, just do built-in.
321 # If we have only "make modules", don't compile built-in objects.
322 # When we're building modules with modversions, we need to consider
323 # the built-in objects during the descend as well, in order to
324 # make sure the checksums are up to date before we record them.
326 ifeq ($(MAKECMDGOALS),modules)
327 KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
330 # If we have "make <whatever> modules", compile modules
331 # in addition to whatever we do anyway.
332 # Just "make" or "make all" shall build modules as well
334 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
338 ifeq ($(MAKECMDGOALS),)
342 export KBUILD_MODULES KBUILD_BUILTIN
343 export KBUILD_CHECKSRC KBUILD_SRC KBUILD_EXTMOD
345 # We need some generic definitions (do not try to remake the file).
346 scripts/Kbuild.include: ;
347 include scripts/Kbuild.include
349 # Make variables (CC, etc...)
350 AS = $(CROSS_COMPILE)as
351 LD = $(CROSS_COMPILE)ld
352 CC = $(CROSS_COMPILE)gcc
354 AR = $(CROSS_COMPILE)ar
355 NM = $(CROSS_COMPILE)nm
356 STRIP = $(CROSS_COMPILE)strip
357 OBJCOPY = $(CROSS_COMPILE)objcopy
358 OBJDUMP = $(CROSS_COMPILE)objdump
360 GENKSYMS = scripts/genksyms/genksyms
361 INSTALLKERNEL := installkernel
362 DEPMOD = /sbin/depmod
367 CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
368 -Wbitwise -Wno-return-void $(CF)
377 # Use USERINCLUDE when you must reference the UAPI directories only.
379 -I$(srctree)/arch/$(hdr-arch)/include/uapi \
380 -I$(objtree)/arch/$(hdr-arch)/include/generated/uapi \
381 -I$(srctree)/include/uapi \
382 -I$(objtree)/include/generated/uapi \
383 -include $(srctree)/include/linux/kconfig.h
385 # Use LINUXINCLUDE when you must reference the include/ directory.
386 # Needed to be compatible with the O= option
388 -I$(srctree)/arch/$(hdr-arch)/include \
389 -I$(objtree)/arch/$(hdr-arch)/include/generated \
390 $(if $(KBUILD_SRC), -I$(srctree)/include) \
391 -I$(objtree)/include \
394 KBUILD_AFLAGS := -D__ASSEMBLY__
395 KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
396 -fno-strict-aliasing -fno-common -fshort-wchar \
397 -Werror-implicit-function-declaration \
398 -Wno-format-security \
400 KBUILD_CPPFLAGS := -D__KERNEL__
401 KBUILD_AFLAGS_KERNEL :=
402 KBUILD_CFLAGS_KERNEL :=
403 KBUILD_AFLAGS_MODULE := -DMODULE
404 KBUILD_CFLAGS_MODULE := -DMODULE
405 KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
406 GCC_PLUGINS_CFLAGS :=
408 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
409 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
410 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
412 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
413 export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC
414 export CPP AR NM STRIP OBJCOPY OBJDUMP HOSTLDFLAGS HOST_LOADLIBES
415 export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE
416 export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
418 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
419 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
420 export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN
421 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
422 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
423 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
424 export KBUILD_ARFLAGS
426 # When compiling out-of-tree modules, put MODVERDIR in the module
427 # tree rather than in the kernel tree. The kernel tree might
429 export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
431 # Files to ignore in find ... statements
433 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
434 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
436 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
437 --exclude CVS --exclude .pc --exclude .hg --exclude .git
439 # ===========================================================================
440 # Rules shared between *config targets and build targets
442 # Basic helpers built in scripts/basic/
443 PHONY += scripts_basic
445 $(Q)$(MAKE) $(build)=scripts/basic
446 $(Q)rm -f .tmp_quiet_recordmcount
448 # To avoid any implicit rule to kick in, define an empty command.
449 scripts/basic/%: scripts_basic ;
451 PHONY += outputmakefile
452 # outputmakefile generates a Makefile in the output directory, if using a
453 # separate output directory. This allows convenient use of make in the
456 ifneq ($(KBUILD_SRC),)
457 $(Q)ln -fsn $(srctree) source
458 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile \
459 $(srctree) $(objtree) $(VERSION) $(PATCHLEVEL)
462 # Support for using generic headers in asm-generic
463 PHONY += asm-generic uapi-asm-generic
464 asm-generic: uapi-asm-generic
465 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
466 src=asm obj=arch/$(SRCARCH)/include/generated/asm
468 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
469 src=uapi/asm obj=arch/$(SRCARCH)/include/generated/uapi/asm
471 # To make sure we do not include .config for any of the *config targets
472 # catch them early, and hand them over to scripts/kconfig/Makefile
473 # It is allowed to specify more targets when calling make, including
474 # mixing *config targets and build targets.
475 # For example 'make oldconfig all'.
476 # Detect when mixed targets is specified, and make a second invocation
477 # of make so .config is not included in this case either (for *config).
479 version_h := include/generated/uapi/linux/version.h
480 old_version_h := include/linux/version.h
482 no-dot-config-targets := clean mrproper distclean \
483 cscope gtags TAGS tags help% %docs check% coccicheck \
484 $(version_h) headers_% archheaders archscripts \
485 kernelversion %src-pkg
491 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
492 ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
497 ifeq ($(KBUILD_EXTMOD),)
498 ifneq ($(filter config %config,$(MAKECMDGOALS)),)
500 ifneq ($(words $(MAKECMDGOALS)),1)
505 # install and modules_install need also be processed one by one
506 ifneq ($(filter install,$(MAKECMDGOALS)),)
507 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
512 ifeq ($(mixed-targets),1)
513 # ===========================================================================
514 # We're called with mixed targets (*config and build targets).
515 # Handle them one by one.
517 PHONY += $(MAKECMDGOALS) __build_one_by_one
519 $(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
524 for i in $(MAKECMDGOALS); do \
525 $(MAKE) -f $(srctree)/Makefile $$i; \
529 ifeq ($(config-targets),1)
530 # ===========================================================================
531 # *config targets only - make sure prerequisites are updated, and descend
532 # in scripts/kconfig to make the *config target
534 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
535 # KBUILD_DEFCONFIG may point out an alternative default configuration
536 # used for 'make defconfig'
537 include arch/$(SRCARCH)/Makefile
538 export KBUILD_DEFCONFIG KBUILD_KCONFIG
540 config: scripts_basic outputmakefile FORCE
541 $(Q)$(MAKE) $(build)=scripts/kconfig $@
543 %config: scripts_basic outputmakefile FORCE
544 $(Q)$(MAKE) $(build)=scripts/kconfig $@
547 # ===========================================================================
548 # Build targets only - this includes vmlinux, arch specific targets, clean
549 # targets and others. In general all targets except *config targets.
551 ifeq ($(KBUILD_EXTMOD),)
552 # Additional helpers built in scripts/
553 # Carefully list dependencies so we do not try to build scripts twice
556 scripts: scripts_basic include/config/auto.conf include/config/tristate.conf \
557 asm-generic gcc-plugins
558 $(Q)$(MAKE) $(build)=$(@)
560 # Objects we will link into vmlinux / subdirs we need to visit
562 drivers-y := drivers/ sound/ firmware/
567 endif # KBUILD_EXTMOD
569 ifeq ($(dot-config),1)
571 -include include/config/auto.conf
573 ifeq ($(KBUILD_EXTMOD),)
574 # Read in dependencies to all Kconfig* files, make sure to run
575 # oldconfig if changes are detected.
576 -include include/config/auto.conf.cmd
578 # To avoid any implicit rule to kick in, define an empty command
579 $(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;
581 # If .config is newer than include/config/auto.conf, someone tinkered
582 # with it and forgot to run make oldconfig.
583 # if auto.conf.cmd is missing then we are probably in a cleaned tree so
584 # we execute the config step to be sure to catch updated Kconfig files
585 include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
586 $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig
588 # external modules needs include/generated/autoconf.h and include/config/auto.conf
589 # but do not care if they are up-to-date. Use auto.conf to trigger the test
590 PHONY += include/config/auto.conf
592 include/config/auto.conf:
593 $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
595 echo >&2 " ERROR: Kernel configuration is invalid."; \
596 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
597 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
601 endif # KBUILD_EXTMOD
604 # Dummy target needed, because used as prerequisite
605 include/config/auto.conf: ;
606 endif # $(dot-config)
608 # For the kernel to actually contain only the needed exported symbols,
609 # we have to build modules as well to determine what those symbols are.
610 # (this can be evaluated only once include/config/auto.conf has been included)
611 ifdef CONFIG_TRIM_UNUSED_KSYMS
615 # The all: target is the default when no target is given on the
617 # This allow a user to issue only 'make' to build a kernel including modules
618 # Defaults to vmlinux, but the arch makefile usually adds further targets
621 KBUILD_CFLAGS += $(call cc-option,-fno-PIE)
622 KBUILD_AFLAGS += $(call cc-option,-fno-PIE)
623 CFLAGS_GCOV := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,)
624 CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,)
625 export CFLAGS_GCOV CFLAGS_KCOV
627 # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
628 # values of the respective KBUILD_* variables
632 include arch/$(SRCARCH)/Makefile
634 KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
635 KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
636 KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
637 KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
638 KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context)
640 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
641 KBUILD_CFLAGS += $(call cc-option,-Oz,-Os)
642 KBUILD_CFLAGS += $(call cc-disable-warning,maybe-uninitialized,)
644 ifdef CONFIG_PROFILE_ALL_BRANCHES
645 KBUILD_CFLAGS += -O2 $(call cc-disable-warning,maybe-uninitialized,)
651 KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \
652 $(call cc-disable-warning,maybe-uninitialized,))
654 # Tell gcc to never replace conditional load with a non-conditional one
655 KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
657 # check for 'asm goto'
658 ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y)
659 KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
660 KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO
663 include scripts/Makefile.gcc-plugins
665 ifdef CONFIG_READABLE_ASM
666 # Disable optimizations that make assembler listings hard to read.
667 # reorder blocks reorders the control in the function
668 # ipa clone creates specialized cloned functions
669 # partial inlining inlines only parts of functions
670 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
671 $(call cc-option,-fno-ipa-cp-clone,) \
672 $(call cc-option,-fno-partial-inlining)
675 ifneq ($(CONFIG_FRAME_WARN),0)
676 KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
679 # This selects the stack protector compiler flag. Testing it is delayed
680 # until after .config has been reprocessed, in the prepare-compiler-check
682 ifdef CONFIG_CC_STACKPROTECTOR_REGULAR
683 stackp-flag := -fstack-protector
684 stackp-name := REGULAR
686 ifdef CONFIG_CC_STACKPROTECTOR_STRONG
687 stackp-flag := -fstack-protector-strong
688 stackp-name := STRONG
690 # Force off for distro compilers that enable stack protector by default.
691 stackp-flag := $(call cc-option, -fno-stack-protector)
694 # Find arch-specific stack protector compiler sanity-checking script.
695 ifdef CONFIG_CC_STACKPROTECTOR
696 stackp-path := $(srctree)/scripts/gcc-$(SRCARCH)_$(BITS)-has-stack-protector.sh
697 stackp-check := $(wildcard $(stackp-path))
699 KBUILD_CFLAGS += $(stackp-flag)
701 ifeq ($(cc-name),clang)
702 ifneq ($(CROSS_COMPILE),)
703 CLANG_TARGET := --target=$(notdir $(CROSS_COMPILE:%-=%))
704 GCC_TOOLCHAIN := $(realpath $(dir $(shell which $(LD)))/..)
706 ifneq ($(GCC_TOOLCHAIN),)
707 CLANG_GCC_TC := --gcc-toolchain=$(GCC_TOOLCHAIN)
709 KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
710 KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
711 KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
712 KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable)
713 KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
714 KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
715 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
716 # Quiet clang warning: comparison of unsigned expression < 0 is always false
717 KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
718 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
719 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
720 # See modpost pattern 2
721 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
722 KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
723 KBUILD_CFLAGS += $(call cc-option, -no-integrated-as)
724 KBUILD_AFLAGS += $(call cc-option, -no-integrated-as)
727 # These warnings generated too much noise in a regular build.
728 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
729 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
730 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
733 ifdef CONFIG_FRAME_POINTER
734 KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
736 # Some targets (ARM with Thumb2, for example), can't be built with frame
737 # pointers. For those, we don't have FUNCTION_TRACER automatically
738 # select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
739 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
740 # -fomit-frame-pointer with FUNCTION_TRACER.
741 ifndef CONFIG_FUNCTION_TRACER
742 KBUILD_CFLAGS += -fomit-frame-pointer
746 KBUILD_CFLAGS += $(call cc-option, -fno-var-tracking-assignments)
748 ifdef CONFIG_DEBUG_INFO
749 ifdef CONFIG_DEBUG_INFO_SPLIT
750 KBUILD_CFLAGS += $(call cc-option, -gsplit-dwarf, -g)
754 KBUILD_AFLAGS += -Wa,-gdwarf-2
756 ifdef CONFIG_DEBUG_INFO_DWARF4
757 KBUILD_CFLAGS += $(call cc-option, -gdwarf-4,)
760 ifdef CONFIG_DEBUG_INFO_REDUCED
761 KBUILD_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
762 $(call cc-option,-fno-var-tracking)
765 ifdef CONFIG_FUNCTION_TRACER
766 ifndef CC_FLAGS_FTRACE
767 CC_FLAGS_FTRACE := -pg
769 export CC_FLAGS_FTRACE
770 ifdef CONFIG_HAVE_FENTRY
771 CC_USING_FENTRY := $(call cc-option, -mfentry -DCC_USING_FENTRY)
773 KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_USING_FENTRY)
774 KBUILD_AFLAGS += $(CC_USING_FENTRY)
775 ifdef CONFIG_DYNAMIC_FTRACE
776 ifdef CONFIG_HAVE_C_RECORDMCOUNT
777 BUILD_C_RECORDMCOUNT := y
778 export BUILD_C_RECORDMCOUNT
783 # We trigger additional mismatches with less inlining
784 ifdef CONFIG_DEBUG_SECTION_MISMATCH
785 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
788 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
789 KBUILD_CFLAGS += $(call cc-option,-ffunction-sections,)
790 KBUILD_CFLAGS += $(call cc-option,-fdata-sections,)
793 # arch Makefile may override CC so keep this after arch Makefile is included
794 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
795 CHECKFLAGS += $(NOSTDINC_FLAGS)
797 # warn about C99 declaration after statement
798 KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
800 # disable pointer signed / unsigned warnings in gcc 4.0
801 KBUILD_CFLAGS += $(call cc-disable-warning, pointer-sign)
803 # disable invalid "can't wrap" optimizations for signed / pointers
804 KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
806 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
807 KBUILD_CFLAGS += $(call cc-option,-fno-stack-check,)
809 # conserve stack if available
810 KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
812 # disallow errors like 'EXPORT_GPL(foo);' with missing header
813 KBUILD_CFLAGS += $(call cc-option,-Werror=implicit-int)
815 # require functions to have arguments in prototypes, not empty 'int foo()'
816 KBUILD_CFLAGS += $(call cc-option,-Werror=strict-prototypes)
818 # Prohibit date/time macros, which would make the build non-deterministic
819 KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
821 # enforce correct pointer usage
822 KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
824 # Require designated initializers for all marked structures
825 KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
827 # use the deterministic mode of AR if available
828 KBUILD_ARFLAGS := $(call ar-option,D)
830 include scripts/Makefile.kasan
831 include scripts/Makefile.extrawarn
832 include scripts/Makefile.ubsan
834 # Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
836 KBUILD_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS)
837 KBUILD_AFLAGS += $(ARCH_AFLAGS) $(KAFLAGS)
838 KBUILD_CFLAGS += $(ARCH_CFLAGS) $(KCFLAGS)
840 # Use --build-id when available.
841 LDFLAGS_BUILD_ID := $(patsubst -Wl$(comma)%,%,\
842 $(call cc-ldoption, -Wl$(comma)--build-id,))
843 KBUILD_LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
844 LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
846 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
847 LDFLAGS_vmlinux += $(call ld-option, --gc-sections,)
850 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
851 LDFLAGS_vmlinux += $(call ld-option, -X,)
854 # Default kernel image to build when no specific target is given.
855 # KBUILD_IMAGE may be overruled on the command line or
856 # set in the environment
857 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
859 export KBUILD_IMAGE ?= vmlinux
862 # INSTALL_PATH specifies where to place the updated kernel and system map
863 # images. Default is /boot, but you can set it to other values
864 export INSTALL_PATH ?= /boot
867 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
868 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
869 # an argument if needed. Otherwise it defaults to the kernel install path
871 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
874 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
875 # relocations required by build roots. This is not defined in the
876 # makefile but the argument can be passed to make if needed.
879 MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
883 # INSTALL_MOD_STRIP, if defined, will cause modules to be
884 # stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
885 # the default option --strip-debug will be used. Otherwise,
886 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
888 ifdef INSTALL_MOD_STRIP
889 ifeq ($(INSTALL_MOD_STRIP),1)
890 mod_strip_cmd = $(STRIP) --strip-debug
892 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
893 endif # INSTALL_MOD_STRIP=1
896 endif # INSTALL_MOD_STRIP
899 # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
900 # after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
901 # or CONFIG_MODULE_COMPRESS_XZ.
903 mod_compress_cmd = true
904 ifdef CONFIG_MODULE_COMPRESS
905 ifdef CONFIG_MODULE_COMPRESS_GZIP
906 mod_compress_cmd = gzip -n -f
907 endif # CONFIG_MODULE_COMPRESS_GZIP
908 ifdef CONFIG_MODULE_COMPRESS_XZ
909 mod_compress_cmd = xz -f
910 endif # CONFIG_MODULE_COMPRESS_XZ
911 endif # CONFIG_MODULE_COMPRESS
912 export mod_compress_cmd
914 # Select initial ramdisk compression format, default is gzip(1).
915 # This shall be used by the dracut(8) tool while creating an initramfs image.
917 INITRD_COMPRESS-y := gzip
918 INITRD_COMPRESS-$(CONFIG_RD_BZIP2) := bzip2
919 INITRD_COMPRESS-$(CONFIG_RD_LZMA) := lzma
920 INITRD_COMPRESS-$(CONFIG_RD_XZ) := xz
921 INITRD_COMPRESS-$(CONFIG_RD_LZO) := lzo
922 INITRD_COMPRESS-$(CONFIG_RD_LZ4) := lz4
923 # do not export INITRD_COMPRESS, since we didn't actually
924 # choose a sane default compression above.
925 # export INITRD_COMPRESS := $(INITRD_COMPRESS-y)
927 ifdef CONFIG_MODULE_SIG_ALL
928 $(eval $(call config_filename,MODULE_SIG_KEY))
930 mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
936 ifdef CONFIG_STACK_VALIDATION
937 has_libelf := $(call try-run,\
938 echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0)
939 ifeq ($(has_libelf),1)
940 objtool_target := tools/objtool FORCE
942 ifdef CONFIG_UNWINDER_ORC
943 $(error "Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel")
945 $(warning "Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel")
947 SKIP_STACK_VALIDATION := 1
948 export SKIP_STACK_VALIDATION
953 ifeq ($(KBUILD_EXTMOD),)
954 core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
956 vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
957 $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
958 $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
960 vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
961 $(init-) $(core-) $(drivers-) $(net-) $(libs-) $(virt-))))
963 init-y := $(patsubst %/, %/built-in.o, $(init-y))
964 core-y := $(patsubst %/, %/built-in.o, $(core-y))
965 drivers-y := $(patsubst %/, %/built-in.o, $(drivers-y))
966 net-y := $(patsubst %/, %/built-in.o, $(net-y))
967 libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
968 libs-y2 := $(filter-out %.a, $(patsubst %/, %/built-in.o, $(libs-y)))
969 virt-y := $(patsubst %/, %/built-in.o, $(virt-y))
971 # Externally visible symbols (used by link-vmlinux.sh)
972 export KBUILD_VMLINUX_INIT := $(head-y) $(init-y)
973 export KBUILD_VMLINUX_MAIN := $(core-y) $(libs-y2) $(drivers-y) $(net-y) $(virt-y)
974 export KBUILD_VMLINUX_LIBS := $(libs-y1)
975 export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
976 export LDFLAGS_vmlinux
977 # used by scripts/package/Makefile
978 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools)
980 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_INIT) $(KBUILD_VMLINUX_MAIN) $(KBUILD_VMLINUX_LIBS)
982 # Include targets which we want to execute sequentially if the rest of the
983 # kernel build went well. If CONFIG_TRIM_UNUSED_KSYMS is set, this might be
984 # evaluated more than once.
985 PHONY += vmlinux_prereq
986 vmlinux_prereq: $(vmlinux-deps) FORCE
987 ifdef CONFIG_HEADERS_CHECK
988 $(Q)$(MAKE) -f $(srctree)/Makefile headers_check
990 ifdef CONFIG_GDB_SCRIPTS
991 $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
993 ifdef CONFIG_TRIM_UNUSED_KSYMS
994 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
995 "$(MAKE) -f $(srctree)/Makefile vmlinux"
998 # standalone target for easier testing
999 include/generated/autoksyms.h: FORCE
1000 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh true
1002 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1004 # Final link of vmlinux with optional arch pass after final link
1005 cmd_link-vmlinux = \
1006 $(CONFIG_SHELL) $< $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) ; \
1007 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1009 vmlinux: scripts/link-vmlinux.sh vmlinux_prereq $(vmlinux-deps) FORCE
1010 +$(call if_changed,link-vmlinux)
1012 # Build samples along the rest of the kernel
1013 ifdef CONFIG_SAMPLES
1014 vmlinux-dirs += samples
1017 # The actual objects are generated when descending,
1018 # make sure no implicit rule kicks in
1019 $(sort $(vmlinux-deps)): $(vmlinux-dirs) ;
1021 # Handle descending into subdirectories listed in $(vmlinux-dirs)
1022 # Preset locale variables to speed up the build process. Limit locale
1023 # tweaks to this spot to avoid wrong language settings when running
1024 # make menuconfig etc.
1025 # Error messages still appears in the original language
1027 PHONY += $(vmlinux-dirs)
1028 $(vmlinux-dirs): prepare scripts
1029 $(Q)$(MAKE) $(build)=$@
1031 define filechk_kernel.release
1032 echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1035 # Store (new) KERNELRELEASE string in include/config/kernel.release
1036 include/config/kernel.release: include/config/auto.conf FORCE
1037 $(call filechk,kernel.release)
1040 # Things we need to do before we recursively start building the kernel
1041 # or the modules are listed in "prepare".
1042 # A multi level approach is used. prepareN is processed before prepareN-1.
1043 # archprepare is used in arch Makefiles and when processed asm symlink,
1044 # version.h and scripts_basic is processed / created.
1046 # Listed in dependency order
1047 PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3
1049 # prepare3 is used to check if we are building in a separate output directory,
1051 # 1) Check that make has not been executed in the kernel src $(srctree)
1052 prepare3: include/config/kernel.release
1053 ifneq ($(KBUILD_SRC),)
1054 @$(kecho) ' Using $(srctree) as source for kernel'
1055 $(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
1056 echo >&2 " $(srctree) is not clean, please run 'make mrproper'"; \
1057 echo >&2 " in the '$(srctree)' directory.";\
1062 # prepare2 creates a makefile if using a separate output directory.
1063 # From this point forward, .config has been reprocessed, so any rules
1064 # that need to depend on updated CONFIG_* values can be checked here.
1065 prepare2: prepare3 prepare-compiler-check outputmakefile asm-generic
1067 prepare1: prepare2 $(version_h) include/generated/utsrelease.h \
1068 include/config/auto.conf
1071 archprepare: archheaders archscripts prepare1 scripts_basic
1073 prepare0: archprepare gcc-plugins
1074 $(Q)$(MAKE) $(build)=.
1076 # All the preparing..
1077 prepare: prepare0 prepare-objtool
1079 PHONY += prepare-objtool
1080 prepare-objtool: $(objtool_target)
1082 # Check for CONFIG flags that require compiler support. Abort the build
1083 # after .config has been processed, but before the kernel build starts.
1085 # For security-sensitive CONFIG options, we don't want to fallback and/or
1086 # silently change which compiler flags will be used, since that leads to
1087 # producing kernels with different security feature characteristics
1088 # depending on the compiler used. (For example, "But I selected
1089 # CC_STACKPROTECTOR_STRONG! Why did it build with _REGULAR?!")
1090 PHONY += prepare-compiler-check
1091 prepare-compiler-check: FORCE
1092 # Make sure compiler supports requested stack protector flag.
1094 ifeq ($(call cc-option, $(stackp-flag)),)
1095 @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1096 $(stackp-flag) not supported by compiler >&2 && exit 1
1099 # Make sure compiler does not have buggy stack-protector support.
1101 ifneq ($(shell $(CONFIG_SHELL) $(stackp-check) $(CC) $(KBUILD_CPPFLAGS) $(biarch)),y)
1102 @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1103 $(stackp-flag) available but compiler is broken >&2 && exit 1
1108 # Generate some files
1109 # ---------------------------------------------------------------------------
1111 # KERNELRELEASE can change from a few different places, meaning version.h
1112 # needs to be updated, so this check is forced on all builds
1115 define filechk_utsrelease.h
1116 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1117 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1120 (echo \#define UTS_RELEASE \"$(KERNELRELEASE)\";)
1123 define filechk_version.h
1124 (echo \#define LINUX_VERSION_CODE $(shell \
1125 expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
1126 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))';)
1129 $(version_h): $(srctree)/Makefile FORCE
1130 $(call filechk,version.h)
1131 $(Q)rm -f $(old_version_h)
1133 include/generated/utsrelease.h: include/config/kernel.release FORCE
1134 $(call filechk,utsrelease.h)
1138 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1139 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1141 # ---------------------------------------------------------------------------
1144 #Default location for installed headers
1145 export INSTALL_HDR_PATH = $(objtree)/usr
1147 # If we do an all arch process set dst to include/arch-$(hdr-arch)
1148 hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(hdr-arch), dst=include)
1150 PHONY += archheaders
1153 PHONY += archscripts
1157 __headers: $(version_h) scripts_basic uapi-asm-generic archheaders archscripts
1158 $(Q)$(MAKE) $(build)=scripts build_unifdef
1160 PHONY += headers_install_all
1161 headers_install_all:
1162 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh install
1164 PHONY += headers_install
1165 headers_install: __headers
1166 $(if $(wildcard $(srctree)/arch/$(hdr-arch)/include/uapi/asm/Kbuild),, \
1167 $(error Headers not exportable for the $(SRCARCH) architecture))
1168 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include
1169 $(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/uapi $(hdr-dst)
1171 PHONY += headers_check_all
1172 headers_check_all: headers_install_all
1173 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh check
1175 PHONY += headers_check
1176 headers_check: headers_install
1177 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include HDRCHECK=1
1178 $(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/uapi $(hdr-dst) HDRCHECK=1
1180 # ---------------------------------------------------------------------------
1185 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1187 PHONY += kselftest-clean
1189 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests clean
1191 PHONY += kselftest-merge
1193 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1194 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \
1195 -m $(objtree)/.config \
1196 $(srctree)/tools/testing/selftests/*/config
1197 +$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1199 # ---------------------------------------------------------------------------
1202 ifdef CONFIG_MODULES
1204 # By default, build modules as well
1210 # A module can be listed more than once in obj-m resulting in
1211 # duplicate lines in modules.order files. Those are removed
1212 # using awk while concatenating to the final file.
1215 modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
1216 $(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
1217 @$(kecho) ' Building modules, stage 2.';
1218 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1220 modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
1221 $(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
1223 %/modules.builtin: include/config/auto.conf
1224 $(Q)$(MAKE) $(modbuiltin)=$*
1227 # Target to prepare building external modules
1228 PHONY += modules_prepare
1229 modules_prepare: prepare scripts
1231 # Target to install modules
1232 PHONY += modules_install
1233 modules_install: _modinst_ _modinst_post
1237 @rm -rf $(MODLIB)/kernel
1238 @rm -f $(MODLIB)/source
1239 @mkdir -p $(MODLIB)/kernel
1240 @ln -s $(abspath $(srctree)) $(MODLIB)/source
1241 @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
1242 rm -f $(MODLIB)/build ; \
1243 ln -s $(CURDIR) $(MODLIB)/build ; \
1245 @cp -f $(objtree)/modules.order $(MODLIB)/
1246 @cp -f $(objtree)/modules.builtin $(MODLIB)/
1247 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1249 # This depmod is only for convenience to give the initial
1250 # boot a modules.dep even before / is mounted read-write. However the
1251 # boot script depmod is the master version.
1252 PHONY += _modinst_post
1253 _modinst_post: _modinst_
1256 ifeq ($(CONFIG_MODULE_SIG), y)
1257 PHONY += modules_sign
1259 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1262 else # CONFIG_MODULES
1264 # Modules not configured
1265 # ---------------------------------------------------------------------------
1267 PHONY += modules modules_install
1268 modules modules_install:
1270 @echo >&2 "The present kernel configuration has modules disabled."
1271 @echo >&2 "Type 'make config' and enable loadable module support."
1272 @echo >&2 "Then build a kernel with module support enabled."
1276 endif # CONFIG_MODULES
1279 # Cleaning is done on three levels.
1280 # make clean Delete most generated files
1281 # Leave enough to build external modules
1282 # make mrproper Delete the current configuration, and all generated files
1283 # make distclean Remove editor backup files, patch leftover files and the like
1285 # Directories & files removed with 'make clean'
1286 CLEAN_DIRS += $(MODVERDIR)
1288 # Directories & files removed with 'make mrproper'
1289 MRPROPER_DIRS += include/config usr/include include/generated \
1290 arch/*/include/generated .tmp_objdiff
1291 MRPROPER_FILES += .config .config.old .version .old_version \
1292 Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
1293 signing_key.pem signing_key.priv signing_key.x509 \
1294 x509.genkey extra_certificates signing_key.x509.keyid \
1295 signing_key.x509.signer vmlinux-gdb.py
1297 # clean - Delete most, but leave enough to build external modules
1299 clean: rm-dirs := $(CLEAN_DIRS)
1300 clean: rm-files := $(CLEAN_FILES)
1301 clean-dirs := $(addprefix _clean_, . $(vmlinux-alldirs) Documentation samples)
1303 PHONY += $(clean-dirs) clean archclean vmlinuxclean
1305 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1308 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1309 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1311 clean: archclean vmlinuxclean
1313 # mrproper - Delete all generated files, including .config
1315 mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS))
1316 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1317 mrproper-dirs := $(addprefix _mrproper_,scripts)
1319 PHONY += $(mrproper-dirs) mrproper archmrproper
1321 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1323 mrproper: clean archmrproper $(mrproper-dirs)
1332 @find $(srctree) $(RCS_FIND_IGNORE) \
1333 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1334 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1335 -o -name 'core' \) \
1336 -type f -print | xargs rm -f
1339 # Packaging of the kernel to various formats
1340 # ---------------------------------------------------------------------------
1341 # rpm target kept for backward compatibility
1342 package-dir := scripts/package
1345 $(Q)$(MAKE) $(build)=$(package-dir) $@
1346 %pkg: include/config/kernel.release FORCE
1347 $(Q)$(MAKE) $(build)=$(package-dir) $@
1348 rpm: include/config/kernel.release FORCE
1349 $(Q)$(MAKE) $(build)=$(package-dir) $@
1352 # Brief documentation of the typical targets used
1353 # ---------------------------------------------------------------------------
1355 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1356 boards := $(sort $(notdir $(boards)))
1357 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1358 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1362 @echo 'Cleaning targets:'
1363 @echo ' clean - Remove most generated files but keep the config and'
1364 @echo ' enough build support to build external modules'
1365 @echo ' mrproper - Remove all generated files + config + various backup files'
1366 @echo ' distclean - mrproper + remove editor backup and patch files'
1368 @echo 'Configuration targets:'
1369 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1371 @echo 'Other generic targets:'
1372 @echo ' all - Build all targets marked with [*]'
1373 @echo '* vmlinux - Build the bare kernel'
1374 @echo '* modules - Build all modules'
1375 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1376 @echo ' dir/ - Build all files in dir and below'
1377 @echo ' dir/file.[ois] - Build specified target only'
1378 @echo ' dir/file.ll - Build the LLVM assembly file'
1379 @echo ' (requires compiler support for LLVM assembly generation)'
1380 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1381 @echo ' (requires a recent binutils and recent build (System.map))'
1382 @echo ' dir/file.ko - Build module including final link'
1383 @echo ' modules_prepare - Set up for building external modules'
1384 @echo ' tags/TAGS - Generate tags file for editors'
1385 @echo ' cscope - Generate cscope index'
1386 @echo ' gtags - Generate GNU GLOBAL index'
1387 @echo ' kernelrelease - Output the release version string (use with make -s)'
1388 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1389 @echo ' image_name - Output the image name (use with make -s)'
1390 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1391 echo ' (default: $(INSTALL_HDR_PATH))'; \
1393 @echo 'Static analysers:'
1394 @echo ' checkstack - Generate a list of stack hogs'
1395 @echo ' namespacecheck - Name space analysis on compiled kernel'
1396 @echo ' versioncheck - Sanity check on version.h usage'
1397 @echo ' includecheck - Check for duplicate included header files'
1398 @echo ' export_report - List the usages of all exported symbols'
1399 @echo ' headers_check - Sanity check on exported headers'
1400 @echo ' headerdep - Detect inclusion cycles in headers'
1401 @$(MAKE) -f $(srctree)/scripts/Makefile.help checker-help
1403 @echo 'Kernel selftest:'
1404 @echo ' kselftest - Build and run kernel selftest (run as root)'
1405 @echo ' Build, install, and boot kernel before'
1406 @echo ' running kselftest on it'
1407 @echo ' kselftest-clean - Remove all generated kselftest files'
1408 @echo ' kselftest-merge - Merge all the config dependencies of kselftest to existing'
1411 @echo 'Userspace tools targets:'
1412 @echo ' use "make tools/help"'
1413 @echo ' or "cd tools; make help"'
1415 @echo 'Kernel packaging:'
1416 @$(MAKE) $(build)=$(package-dir) help
1418 @echo 'Documentation targets:'
1419 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1421 @echo 'Architecture specific targets ($(SRCARCH)):'
1422 @$(if $(archhelp),$(archhelp),\
1423 echo ' No architecture specific help defined for $(SRCARCH)')
1426 $(foreach b, $(boards), \
1427 printf " %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1429 @$(if $(board-dirs), \
1430 $(foreach b, $(board-dirs), \
1431 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1432 printf " %-16s - Show all of the above\\n" help-boards; \
1435 @echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1436 @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
1437 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1438 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK (sparse by default)'
1439 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1440 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1441 @echo ' make W=n [targets] Enable extra gcc checks, n=1,2,3 where'
1442 @echo ' 1: warnings which may be relevant and do not occur too often'
1443 @echo ' 2: warnings which occur quite often but may still be relevant'
1444 @echo ' 3: more obscure warnings, can most likely be ignored'
1445 @echo ' Multiple levels can be combined with W=12 or W=123'
1447 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1448 @echo 'For further info see the ./README file'
1451 help-board-dirs := $(addprefix help-,$(board-dirs))
1453 help-boards: $(help-board-dirs)
1455 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1457 $(help-board-dirs): help-%:
1458 @echo 'Architecture specific targets ($(SRCARCH) $*):'
1459 @$(if $(boards-per-dir), \
1460 $(foreach b, $(boards-per-dir), \
1461 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1465 # Documentation targets
1466 # ---------------------------------------------------------------------------
1467 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs linkcheckdocs
1468 PHONY += $(DOC_TARGETS)
1469 $(DOC_TARGETS): scripts_basic FORCE
1470 $(Q)$(MAKE) $(build)=Documentation $@
1472 else # KBUILD_EXTMOD
1475 # External module support.
1476 # When building external modules the kernel used as basis is considered
1477 # read-only, and no consistency checks are made and the make
1478 # system is not used on the basis kernel. If updates are required
1479 # in the basis kernel ordinary make commands (without M=...) must
1482 # The following are the only valid targets when building external
1484 # make M=dir clean Delete all automatically generated files
1485 # make M=dir modules Make all modules in specified dir
1486 # make M=dir Same as 'make M=dir modules'
1487 # make M=dir modules_install
1488 # Install the modules built in the module directory
1489 # Assumes install directory is already created
1491 # We are always building modules
1493 PHONY += crmodverdir
1497 PHONY += $(objtree)/Module.symvers
1498 $(objtree)/Module.symvers:
1499 @test -e $(objtree)/Module.symvers || ( \
1501 echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1502 echo " is missing; modules will have no dependencies and modversions."; \
1505 module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
1506 PHONY += $(module-dirs) modules
1507 $(module-dirs): crmodverdir $(objtree)/Module.symvers
1508 $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
1510 modules: $(module-dirs)
1511 @$(kecho) ' Building modules, stage 2.';
1512 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1514 PHONY += modules_install
1515 modules_install: _emodinst_ _emodinst_post
1517 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1520 $(Q)mkdir -p $(MODLIB)/$(install-dir)
1521 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1523 PHONY += _emodinst_post
1524 _emodinst_post: _emodinst_
1527 clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))
1529 PHONY += $(clean-dirs) clean
1531 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1533 clean: rm-dirs := $(MODVERDIR)
1534 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1538 @echo ' Building external modules.'
1539 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1541 @echo ' modules - default target, build the module(s)'
1542 @echo ' modules_install - install the module'
1543 @echo ' clean - remove generated files in module directory only'
1547 PHONY += prepare scripts
1550 endif # KBUILD_EXTMOD
1552 clean: $(clean-dirs)
1555 @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1556 \( -name '*.[oas]' -o -name '*.ko' -o -name '.*.cmd' \
1560 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1561 -o -name '*.symtypes' -o -name 'modules.order' \
1562 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1563 -o -name '*.c.[012]*.*' \
1565 -o -name '*.gcno' \) -type f -print | xargs rm -f
1567 # Generate tags for editors
1568 # ---------------------------------------------------------------------------
1569 quiet_cmd_tags = GEN $@
1570 cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
1572 tags TAGS cscope gtags: FORCE
1575 # Scripts to check various things for consistency
1576 # ---------------------------------------------------------------------------
1578 PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1581 find $(srctree)/* $(RCS_FIND_IGNORE) \
1582 -name '*.[hcS]' -type f -print | sort \
1583 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1586 find $(srctree)/* $(RCS_FIND_IGNORE) \
1587 -name '*.[hcS]' -type f -print | sort \
1588 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1591 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1594 $(PERL) $(srctree)/scripts/namespace.pl
1597 $(PERL) $(srctree)/scripts/export_report.pl
1599 endif #ifeq ($(config-targets),1)
1600 endif #ifeq ($(mixed-targets),1)
1602 PHONY += checkstack kernelrelease kernelversion image_name
1604 # UML needs a little special treatment here. It wants to use the host
1605 # toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
1606 # else wants $(ARCH), including people doing cross-builds, which means
1607 # that $(SUBARCH) doesn't work here.
1609 CHECKSTACK_ARCH := $(SUBARCH)
1611 CHECKSTACK_ARCH := $(ARCH)
1614 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1615 $(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1618 @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1621 @echo $(KERNELVERSION)
1624 @echo $(KBUILD_IMAGE)
1626 # Clear a bunch of variables before executing the submake
1628 $(Q)mkdir -p $(objtree)/tools
1629 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/
1632 $(Q)mkdir -p $(objtree)/tools
1633 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/ $*
1636 # ---------------------------------------------------------------------------
1637 # Single targets are compatible with:
1638 # - build with mixed source and output
1639 # - build with separate output dir 'make O=...'
1640 # - external modules
1642 # target-dir => where to store outputfile
1643 # build-dir => directory in kernel source tree to use
1645 ifeq ($(KBUILD_EXTMOD),)
1646 build-dir = $(patsubst %/,%,$(dir $@))
1647 target-dir = $(dir $@)
1649 zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
1650 build-dir = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
1651 target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@))
1654 %.s: %.c prepare scripts FORCE
1655 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1656 %.i: %.c prepare scripts FORCE
1657 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1658 %.o: %.c prepare scripts FORCE
1659 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1660 %.lst: %.c prepare scripts FORCE
1661 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1662 %.s: %.S prepare scripts FORCE
1663 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1664 %.o: %.S prepare scripts FORCE
1665 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1666 %.symtypes: %.c prepare scripts FORCE
1667 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1668 %.ll: %.c prepare scripts FORCE
1669 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1672 /: prepare scripts FORCE
1674 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1675 $(build)=$(build-dir)
1676 # Make sure the latest headers are built for Documentation
1677 Documentation/ samples/: headers_install
1678 %/: prepare scripts FORCE
1680 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1681 $(build)=$(build-dir)
1682 %.ko: prepare scripts FORCE
1684 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1685 $(build)=$(build-dir) $(@:.ko=.o)
1686 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1688 # FIXME Should go into a make.lib or something
1689 # ===========================================================================
1691 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs)))
1692 cmd_rmdirs = rm -rf $(rm-dirs)
1694 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
1695 cmd_rmfiles = rm -f $(rm-files)
1697 # Run depmod only if we have System.map and depmod is executable
1698 quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
1699 cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1700 $(KERNELRELEASE) "$(patsubst y,_,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))"
1702 # Create temporary dir for module support files
1703 # clean it up only when building all modules
1704 cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
1705 $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
1707 # read all saved command lines
1709 targets := $(wildcard $(sort $(targets)))
1710 cmd_files := $(wildcard .*.cmd $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
1712 ifneq ($(cmd_files),)
1713 $(cmd_files): ; # Do not try to update included dependency files
1714 include $(cmd_files)
1717 endif # skip-makefile
1722 # Declare the contents of the .PHONY variable as phony. We keep that
1723 # information in a variable so we can use it in if_changed and friends.