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 # That's our default target when none is given on the command line
18 # o Do not use make's built-in rules and variables
19 # (this increases performance and avoids hard-to-debug behaviour);
20 # o Look for make include files relative to root of kernel src
21 MAKEFLAGS += -rR --include-dir=$(CURDIR)
23 # Avoid funny character set dependencies
27 export LC_COLLATE LC_NUMERIC
29 # Avoid interference with shell env settings
32 # We are using a recursive build, so we need to do a little thinking
33 # to get the ordering right.
35 # Most importantly: sub-Makefiles should only ever modify files in
36 # their own directory. If in some directory we have a dependency on
37 # a file in another dir (which doesn't happen often, but it's often
38 # unavoidable when linking the built-in.a targets which finally
39 # turn into vmlinux), we will call a sub make in that other dir, and
40 # after that we are sure that everything which is in that other dir
43 # The only cases where we need to modify files which have global
44 # effects are thus separated out and done before the recursive
45 # descending is started. They are now explicitly listed as the
49 # ---------------------------------------------------------------------------
51 # Normally, we echo the whole command before executing it. By making
52 # that echo $($(quiet)$(cmd)), we now have the possibility to set
53 # $(quiet) to choose other forms of output instead, e.g.
55 # quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
56 # cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
58 # If $(quiet) is empty, the whole command will be printed.
59 # If it is set to "quiet_", only the short version will be printed.
60 # If it is set to "silent_", nothing will be printed at all, since
61 # the variable $(silent_cmd_cc_o_c) doesn't exist.
63 # A simple variant is to prefix commands with $(Q) - that's useful
64 # for commands that shall be hidden in non-verbose mode.
68 # If KBUILD_VERBOSE equals 0 then the above command will be hidden.
69 # If KBUILD_VERBOSE equals 1 then the above command is displayed.
71 # To put more focus on warnings, be less verbose as default
72 # Use 'make V=1' to see the full commands
74 ifeq ("$(origin V)", "command line")
81 ifeq ($(KBUILD_VERBOSE),1)
89 # If the user is running make -s (silent mode), suppress echoing of
92 ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
97 export quiet Q KBUILD_VERBOSE
99 # kbuild supports saving output files in a separate directory.
100 # To locate output files in a separate directory two syntaxes are supported.
101 # In both cases the working directory must be the root of the kernel src.
103 # Use "make O=dir/to/store/output/files/"
105 # 2) Set KBUILD_OUTPUT
106 # Set the environment variable KBUILD_OUTPUT to point to the directory
107 # where the output files shall be placed.
108 # export KBUILD_OUTPUT=dir/to/store/output/files/
111 # The O= assignment takes precedence over the KBUILD_OUTPUT environment
114 # KBUILD_SRC is not intended to be used by the regular user (for now),
115 # it is set on invocation of make with KBUILD_OUTPUT or O= specified.
116 ifeq ($(KBUILD_SRC),)
118 # OK, Make called in directory where kernel src resides
119 # Do we want to locate output files in a separate directory?
120 ifeq ("$(origin O)", "command line")
121 KBUILD_OUTPUT := $(O)
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 := $(M)
190 ifeq ($(KBUILD_SRC),)
191 # building in the source tree
194 ifeq ($(KBUILD_SRC)/,$(dir $(CURDIR)))
195 # building in a subdirectory of the source tree
198 srctree := $(KBUILD_SRC)
202 export KBUILD_CHECKSRC KBUILD_EXTMOD KBUILD_SRC
208 VPATH := $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))
210 export srctree objtree VPATH
212 # To make sure we do not include .config for any of the *config targets
213 # catch them early, and hand them over to scripts/kconfig/Makefile
214 # It is allowed to specify more targets when calling make, including
215 # mixing *config targets and build targets.
216 # For example 'make oldconfig all'.
217 # Detect when mixed targets is specified, and make a second invocation
218 # of make so .config is not included in this case either (for *config).
220 version_h := include/generated/uapi/linux/version.h
221 old_version_h := include/linux/version.h
223 clean-targets := %clean mrproper cleandocs
224 no-dot-config-targets := $(clean-targets) \
225 cscope gtags TAGS tags help% %docs check% coccicheck \
226 $(version_h) headers_% archheaders archscripts \
227 kernelversion %src-pkg
233 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
234 ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
239 ifeq ($(KBUILD_EXTMOD),)
240 ifneq ($(filter config %config,$(MAKECMDGOALS)),)
242 ifneq ($(words $(MAKECMDGOALS)),1)
248 # For "make -j clean all", "make -j mrproper defconfig all", etc.
249 ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
250 ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
255 # install and modules_install need also be processed one by one
256 ifneq ($(filter install,$(MAKECMDGOALS)),)
257 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
262 ifeq ($(mixed-targets),1)
263 # ===========================================================================
264 # We're called with mixed targets (*config and build targets).
265 # Handle them one by one.
267 PHONY += $(MAKECMDGOALS) __build_one_by_one
269 $(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
274 for i in $(MAKECMDGOALS); do \
275 $(MAKE) -f $(srctree)/Makefile $$i; \
280 # We need some generic definitions (do not try to remake the file).
281 scripts/Kbuild.include: ;
282 include scripts/Kbuild.include
284 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
285 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
286 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
287 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
289 # SUBARCH tells the usermode build what the underlying arch is. That is set
290 # first, and if a usermode build is happening, the "ARCH=um" on the command
291 # line overrides the setting of ARCH below. If a native build is happening,
292 # then ARCH is assigned, getting whatever value it gets normally, and
293 # SUBARCH is subsequently ignored.
295 SUBARCH := $(shell uname -m | sed -e s/i.86/x86/ -e s/x86_64/x86/ \
296 -e s/sun4u/sparc64/ \
297 -e s/arm.*/arm/ -e s/sa110/arm/ \
298 -e s/s390x/s390/ -e s/parisc64/parisc/ \
299 -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
300 -e s/sh[234].*/sh/ -e s/aarch64.*/arm64/ \
303 # Cross compiling and selecting different set of gcc/bin-utils
304 # ---------------------------------------------------------------------------
306 # When performing cross compilation for other architectures ARCH shall be set
307 # to the target architecture. (See arch/* for the possibilities).
308 # ARCH can be set during invocation of make:
310 # Another way is to have ARCH set in the environment.
311 # The default ARCH is the host where make is executed.
313 # CROSS_COMPILE specify the prefix used for all executables used
314 # during compilation. Only gcc and related bin-utils executables
315 # are prefixed with $(CROSS_COMPILE).
316 # CROSS_COMPILE can be set on the command line
317 # make CROSS_COMPILE=ia64-linux-
318 # Alternatively CROSS_COMPILE can be set in the environment.
319 # A third alternative is to store a setting in .config so that plain
320 # "make" in the configured kernel build directory always uses that.
321 # Default value for CROSS_COMPILE is not to prefix executables
322 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
324 CROSS_COMPILE ?= $(CONFIG_CROSS_COMPILE:"%"=%)
326 # Architecture as present in compile.h
327 UTS_MACHINE := $(ARCH)
330 # Additional ARCH settings for x86
334 ifeq ($(ARCH),x86_64)
338 # Additional ARCH settings for sparc
339 ifeq ($(ARCH),sparc32)
342 ifeq ($(ARCH),sparc64)
346 # Additional ARCH settings for sh
351 KCONFIG_CONFIG ?= .config
352 export KCONFIG_CONFIG
354 # SHELL used by kbuild
355 CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
356 else if [ -x /bin/bash ]; then echo /bin/bash; \
357 else echo sh; fi ; fi)
359 HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS)
360 HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS)
361 HOST_LFS_LIBS := $(shell getconf LFS_LIBS)
365 HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 \
366 -fomit-frame-pointer -std=gnu89 $(HOST_LFS_CFLAGS)
367 HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS)
368 HOSTLDFLAGS := $(HOST_LFS_LDFLAGS)
369 HOST_LOADLIBES := $(HOST_LFS_LIBS)
371 # Make variables (CC, etc...)
372 AS = $(CROSS_COMPILE)as
373 LD = $(CROSS_COMPILE)ld
374 CC = $(CROSS_COMPILE)gcc
376 AR = $(CROSS_COMPILE)ar
377 NM = $(CROSS_COMPILE)nm
378 STRIP = $(CROSS_COMPILE)strip
379 OBJCOPY = $(CROSS_COMPILE)objcopy
380 OBJDUMP = $(CROSS_COMPILE)objdump
384 GENKSYMS = scripts/genksyms/genksyms
385 INSTALLKERNEL := installkernel
386 DEPMOD = /sbin/depmod
393 CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
394 -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
403 # Use USERINCLUDE when you must reference the UAPI directories only.
405 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
406 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
407 -I$(srctree)/include/uapi \
408 -I$(objtree)/include/generated/uapi \
409 -include $(srctree)/include/linux/kconfig.h
411 # Use LINUXINCLUDE when you must reference the include/ directory.
412 # Needed to be compatible with the O= option
414 -I$(srctree)/arch/$(SRCARCH)/include \
415 -I$(objtree)/arch/$(SRCARCH)/include/generated \
416 $(if $(KBUILD_SRC), -I$(srctree)/include) \
417 -I$(objtree)/include \
420 KBUILD_AFLAGS := -D__ASSEMBLY__
421 KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
422 -fno-strict-aliasing -fno-common -fshort-wchar \
423 -Werror-implicit-function-declaration \
424 -Wno-format-security \
426 KBUILD_CPPFLAGS := -D__KERNEL__
427 KBUILD_AFLAGS_KERNEL :=
428 KBUILD_CFLAGS_KERNEL :=
429 KBUILD_AFLAGS_MODULE := -DMODULE
430 KBUILD_CFLAGS_MODULE := -DMODULE
431 KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
433 GCC_PLUGINS_CFLAGS :=
435 export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC
436 export CPP AR NM STRIP OBJCOPY OBJDUMP HOSTLDFLAGS HOST_LOADLIBES
437 export MAKE LEX YACC AWK GENKSYMS INSTALLKERNEL PERL PYTHON PYTHON2 PYTHON3 UTS_MACHINE
438 export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
440 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
441 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
442 export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN
443 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
444 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
445 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
446 export KBUILD_ARFLAGS
448 # When compiling out-of-tree modules, put MODVERDIR in the module
449 # tree rather than in the kernel tree. The kernel tree might
451 export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
453 # Files to ignore in find ... statements
455 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
456 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
458 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
459 --exclude CVS --exclude .pc --exclude .hg --exclude .git
461 # ===========================================================================
462 # Rules shared between *config targets and build targets
464 # Basic helpers built in scripts/basic/
465 PHONY += scripts_basic
467 $(Q)$(MAKE) $(build)=scripts/basic
468 $(Q)rm -f .tmp_quiet_recordmcount
470 # To avoid any implicit rule to kick in, define an empty command.
471 scripts/basic/%: scripts_basic ;
473 PHONY += outputmakefile
474 # outputmakefile generates a Makefile in the output directory, if using a
475 # separate output directory. This allows convenient use of make in the
478 ifneq ($(KBUILD_SRC),)
479 $(Q)ln -fsn $(srctree) source
480 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile \
481 $(srctree) $(objtree) $(VERSION) $(PATCHLEVEL)
484 ifeq ($(cc-name),clang)
485 ifneq ($(CROSS_COMPILE),)
486 CLANG_TARGET := --target=$(notdir $(CROSS_COMPILE:%-=%))
487 GCC_TOOLCHAIN := $(realpath $(dir $(shell which $(LD)))/..)
489 ifneq ($(GCC_TOOLCHAIN),)
490 CLANG_GCC_TC := --gcc-toolchain=$(GCC_TOOLCHAIN)
492 KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
493 KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
494 KBUILD_CFLAGS += $(call cc-option, -no-integrated-as)
495 KBUILD_AFLAGS += $(call cc-option, -no-integrated-as)
498 RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
499 RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
500 RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
501 export RETPOLINE_CFLAGS
503 # check for 'asm goto'
504 ifeq ($(call shell-cached,$(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y)
505 CC_HAVE_ASM_GOTO := 1
506 KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
507 KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO
510 ifeq ($(config-targets),1)
511 # ===========================================================================
512 # *config targets only - make sure prerequisites are updated, and descend
513 # in scripts/kconfig to make the *config target
515 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
516 # KBUILD_DEFCONFIG may point out an alternative default configuration
517 # used for 'make defconfig'
518 include arch/$(SRCARCH)/Makefile
519 export KBUILD_DEFCONFIG KBUILD_KCONFIG
521 config: scripts_basic outputmakefile FORCE
522 $(Q)$(MAKE) $(build)=scripts/kconfig $@
524 %config: scripts_basic outputmakefile FORCE
525 $(Q)$(MAKE) $(build)=scripts/kconfig $@
528 # ===========================================================================
529 # Build targets only - this includes vmlinux, arch specific targets, clean
530 # targets and others. In general all targets except *config targets.
532 # If building an external module we do not care about the all: rule
533 # but instead _all depend on modules
535 ifeq ($(KBUILD_EXTMOD),)
541 # Decide whether to build built-in, modular, or both.
542 # Normally, just do built-in.
547 # If we have only "make modules", don't compile built-in objects.
548 # When we're building modules with modversions, we need to consider
549 # the built-in objects during the descend as well, in order to
550 # make sure the checksums are up to date before we record them.
552 ifeq ($(MAKECMDGOALS),modules)
553 KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
556 # If we have "make <whatever> modules", compile modules
557 # in addition to whatever we do anyway.
558 # Just "make" or "make all" shall build modules as well
560 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
564 ifeq ($(MAKECMDGOALS),)
568 export KBUILD_MODULES KBUILD_BUILTIN
570 ifeq ($(KBUILD_EXTMOD),)
571 # Objects we will link into vmlinux / subdirs we need to visit
573 drivers-y := drivers/ sound/ firmware/
578 endif # KBUILD_EXTMOD
580 ifeq ($(dot-config),1)
582 -include include/config/auto.conf
584 ifeq ($(KBUILD_EXTMOD),)
585 # Read in dependencies to all Kconfig* files, make sure to run
586 # oldconfig if changes are detected.
587 -include include/config/auto.conf.cmd
589 # To avoid any implicit rule to kick in, define an empty command
590 $(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;
592 # The actual configuration files used during the build are stored in
593 # include/generated/ and include/config/. Update them if .config is newer than
594 # include/config/auto.conf (which mirrors .config).
595 include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
596 $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
598 # external modules needs include/generated/autoconf.h and include/config/auto.conf
599 # but do not care if they are up-to-date. Use auto.conf to trigger the test
600 PHONY += include/config/auto.conf
602 include/config/auto.conf:
603 $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
605 echo >&2 " ERROR: Kernel configuration is invalid."; \
606 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
607 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
611 endif # KBUILD_EXTMOD
614 # Dummy target needed, because used as prerequisite
615 include/config/auto.conf: ;
616 endif # $(dot-config)
618 # The all: target is the default when no target is given on the
620 # This allow a user to issue only 'make' to build a kernel including modules
621 # Defaults to vmlinux, but the arch makefile usually adds further targets
624 KBUILD_CFLAGS += $(call cc-option,-fno-PIE)
625 KBUILD_AFLAGS += $(call cc-option,-fno-PIE)
626 CFLAGS_GCOV := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,)
627 export CFLAGS_GCOV CFLAGS_KCOV
629 # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
630 # values of the respective KBUILD_* variables
634 include arch/$(SRCARCH)/Makefile
636 KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
637 KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
638 KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
639 KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
640 KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context)
642 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
643 KBUILD_CFLAGS += $(call cc-option,-Oz,-Os)
644 KBUILD_CFLAGS += $(call cc-disable-warning,maybe-uninitialized,)
646 ifdef CONFIG_PROFILE_ALL_BRANCHES
647 KBUILD_CFLAGS += -O2 $(call cc-disable-warning,maybe-uninitialized,)
653 KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \
654 $(call cc-disable-warning,maybe-uninitialized,))
656 # Tell gcc to never replace conditional load with a non-conditional one
657 KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
659 include scripts/Makefile.kcov
660 include scripts/Makefile.gcc-plugins
662 ifdef CONFIG_READABLE_ASM
663 # Disable optimizations that make assembler listings hard to read.
664 # reorder blocks reorders the control in the function
665 # ipa clone creates specialized cloned functions
666 # partial inlining inlines only parts of functions
667 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
668 $(call cc-option,-fno-ipa-cp-clone,) \
669 $(call cc-option,-fno-partial-inlining)
672 ifneq ($(CONFIG_FRAME_WARN),0)
673 KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
676 # This selects the stack protector compiler flag. Testing it is delayed
677 # until after .config has been reprocessed, in the prepare-compiler-check
679 ifdef CONFIG_CC_STACKPROTECTOR_AUTO
680 stackp-flag := $(call cc-option,-fstack-protector-strong,$(call cc-option,-fstack-protector))
683 ifdef CONFIG_CC_STACKPROTECTOR_REGULAR
684 stackp-flag := -fstack-protector
685 stackp-name := REGULAR
687 ifdef CONFIG_CC_STACKPROTECTOR_STRONG
688 stackp-flag := -fstack-protector-strong
689 stackp-name := STRONG
691 # If either there is no stack protector for this architecture or
692 # CONFIG_CC_STACKPROTECTOR_NONE is selected, we're done, and $(stackp-name)
693 # is empty, skipping all remaining stack protector tests.
695 # Force off for distro compilers that enable stack protector by default.
696 KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector)
700 # Find arch-specific stack protector compiler sanity-checking script.
702 ifneq ($(stackp-flag),)
703 stackp-path := $(srctree)/scripts/gcc-$(SRCARCH)_$(BITS)-has-stack-protector.sh
704 stackp-check := $(wildcard $(stackp-path))
705 # If the wildcard test matches a test script, run it to check functionality.
707 ifneq ($(shell $(CONFIG_SHELL) $(stackp-check) $(CC) $(KBUILD_CPPFLAGS) $(biarch)),y)
712 # If the stack protector is functional, enable code that depends on it.
713 KBUILD_CPPFLAGS += -DCONFIG_CC_STACKPROTECTOR
714 # Either we've already detected the flag (for AUTO) or we'll fail the
715 # build in the prepare-compiler-check rule (for specific flag).
716 KBUILD_CFLAGS += $(stackp-flag)
718 # We have to make sure stack protector is unconditionally disabled if
719 # the compiler is broken (in case we're going to continue the build in
721 KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector)
726 ifeq ($(cc-name),clang)
727 KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
728 KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
729 KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
730 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
731 # Quiet clang warning: comparison of unsigned expression < 0 is always false
732 KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
733 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
734 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
735 # See modpost pattern 2
736 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
737 KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
740 # These warnings generated too much noise in a regular build.
741 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
742 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
745 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
746 ifdef CONFIG_FRAME_POINTER
747 KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
749 # Some targets (ARM with Thumb2, for example), can't be built with frame
750 # pointers. For those, we don't have FUNCTION_TRACER automatically
751 # select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
752 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
753 # -fomit-frame-pointer with FUNCTION_TRACER.
754 ifndef CONFIG_FUNCTION_TRACER
755 KBUILD_CFLAGS += -fomit-frame-pointer
759 KBUILD_CFLAGS += $(call cc-option, -fno-var-tracking-assignments)
761 ifdef CONFIG_DEBUG_INFO
762 ifdef CONFIG_DEBUG_INFO_SPLIT
763 KBUILD_CFLAGS += $(call cc-option, -gsplit-dwarf, -g)
767 KBUILD_AFLAGS += -Wa,-gdwarf-2
769 ifdef CONFIG_DEBUG_INFO_DWARF4
770 KBUILD_CFLAGS += $(call cc-option, -gdwarf-4,)
773 ifdef CONFIG_DEBUG_INFO_REDUCED
774 KBUILD_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
775 $(call cc-option,-fno-var-tracking)
778 ifdef CONFIG_FUNCTION_TRACER
779 ifndef CC_FLAGS_FTRACE
780 CC_FLAGS_FTRACE := -pg
782 export CC_FLAGS_FTRACE
783 ifdef CONFIG_HAVE_FENTRY
784 CC_USING_FENTRY := $(call cc-option, -mfentry -DCC_USING_FENTRY)
786 KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_USING_FENTRY)
787 KBUILD_AFLAGS += $(CC_USING_FENTRY)
788 ifdef CONFIG_DYNAMIC_FTRACE
789 ifdef CONFIG_HAVE_C_RECORDMCOUNT
790 BUILD_C_RECORDMCOUNT := y
791 export BUILD_C_RECORDMCOUNT
796 # We trigger additional mismatches with less inlining
797 ifdef CONFIG_DEBUG_SECTION_MISMATCH
798 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
801 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
802 KBUILD_CFLAGS_KERNEL += $(call cc-option,-ffunction-sections,)
803 KBUILD_CFLAGS_KERNEL += $(call cc-option,-fdata-sections,)
806 # arch Makefile may override CC so keep this after arch Makefile is included
807 NOSTDINC_FLAGS += -nostdinc -isystem $(call shell-cached,$(CC) -print-file-name=include)
809 # warn about C99 declaration after statement
810 KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
812 # disable pointer signed / unsigned warnings in gcc 4.0
813 KBUILD_CFLAGS += $(call cc-disable-warning, pointer-sign)
815 # disable invalid "can't wrap" optimizations for signed / pointers
816 KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
818 # clang sets -fmerge-all-constants by default as optimization, but this
819 # is non-conforming behavior for C and in fact breaks the kernel, so we
820 # need to disable it here generally.
821 KBUILD_CFLAGS += $(call cc-option,-fno-merge-all-constants)
823 # for gcc -fno-merge-all-constants disables everything, but it is fine
824 # to have actual conforming behavior enabled.
825 KBUILD_CFLAGS += $(call cc-option,-fmerge-constants)
827 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
828 KBUILD_CFLAGS += $(call cc-option,-fno-stack-check,)
830 # conserve stack if available
831 KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
833 # disallow errors like 'EXPORT_GPL(foo);' with missing header
834 KBUILD_CFLAGS += $(call cc-option,-Werror=implicit-int)
836 # require functions to have arguments in prototypes, not empty 'int foo()'
837 KBUILD_CFLAGS += $(call cc-option,-Werror=strict-prototypes)
839 # Prohibit date/time macros, which would make the build non-deterministic
840 KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
842 # enforce correct pointer usage
843 KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
845 # Require designated initializers for all marked structures
846 KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
848 # change __FILE__ to the relative path from the srctree
849 KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
851 # use the deterministic mode of AR if available
852 KBUILD_ARFLAGS := $(call ar-option,D)
854 include scripts/Makefile.kasan
855 include scripts/Makefile.extrawarn
856 include scripts/Makefile.ubsan
858 # Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
860 KBUILD_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS)
861 KBUILD_AFLAGS += $(ARCH_AFLAGS) $(KAFLAGS)
862 KBUILD_CFLAGS += $(ARCH_CFLAGS) $(KCFLAGS)
864 # Use --build-id when available.
865 LDFLAGS_BUILD_ID := $(call ld-option, --build-id)
866 KBUILD_LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
867 LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
869 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
870 LDFLAGS_vmlinux += $(call ld-option, --gc-sections,)
873 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
874 LDFLAGS_vmlinux += $(call ld-option, -X,)
877 # insure the checker run with the right endianness
878 CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
880 # the checker needs the correct machine size
881 CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
883 # Default kernel image to build when no specific target is given.
884 # KBUILD_IMAGE may be overruled on the command line or
885 # set in the environment
886 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
888 export KBUILD_IMAGE ?= vmlinux
891 # INSTALL_PATH specifies where to place the updated kernel and system map
892 # images. Default is /boot, but you can set it to other values
893 export INSTALL_PATH ?= /boot
896 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
897 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
898 # an argument if needed. Otherwise it defaults to the kernel install path
900 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
903 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
904 # relocations required by build roots. This is not defined in the
905 # makefile but the argument can be passed to make if needed.
908 MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
912 # INSTALL_MOD_STRIP, if defined, will cause modules to be
913 # stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
914 # the default option --strip-debug will be used. Otherwise,
915 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
917 ifdef INSTALL_MOD_STRIP
918 ifeq ($(INSTALL_MOD_STRIP),1)
919 mod_strip_cmd = $(STRIP) --strip-debug
921 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
922 endif # INSTALL_MOD_STRIP=1
925 endif # INSTALL_MOD_STRIP
928 # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
929 # after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
930 # or CONFIG_MODULE_COMPRESS_XZ.
932 mod_compress_cmd = true
933 ifdef CONFIG_MODULE_COMPRESS
934 ifdef CONFIG_MODULE_COMPRESS_GZIP
935 mod_compress_cmd = gzip -n -f
936 endif # CONFIG_MODULE_COMPRESS_GZIP
937 ifdef CONFIG_MODULE_COMPRESS_XZ
938 mod_compress_cmd = xz -f
939 endif # CONFIG_MODULE_COMPRESS_XZ
940 endif # CONFIG_MODULE_COMPRESS
941 export mod_compress_cmd
943 # Select initial ramdisk compression format, default is gzip(1).
944 # This shall be used by the dracut(8) tool while creating an initramfs image.
946 INITRD_COMPRESS-y := gzip
947 INITRD_COMPRESS-$(CONFIG_RD_BZIP2) := bzip2
948 INITRD_COMPRESS-$(CONFIG_RD_LZMA) := lzma
949 INITRD_COMPRESS-$(CONFIG_RD_XZ) := xz
950 INITRD_COMPRESS-$(CONFIG_RD_LZO) := lzo
951 INITRD_COMPRESS-$(CONFIG_RD_LZ4) := lz4
952 # do not export INITRD_COMPRESS, since we didn't actually
953 # choose a sane default compression above.
954 # export INITRD_COMPRESS := $(INITRD_COMPRESS-y)
956 ifdef CONFIG_MODULE_SIG_ALL
957 $(eval $(call config_filename,MODULE_SIG_KEY))
959 mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
965 ifdef CONFIG_STACK_VALIDATION
966 has_libelf := $(call try-run,\
967 echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0)
968 ifeq ($(has_libelf),1)
969 objtool_target := tools/objtool FORCE
971 ifdef CONFIG_UNWINDER_ORC
972 $(error "Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel")
974 $(warning "Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel")
976 SKIP_STACK_VALIDATION := 1
977 export SKIP_STACK_VALIDATION
982 ifeq ($(KBUILD_EXTMOD),)
983 core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
985 vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
986 $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
987 $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
989 vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
990 $(init-) $(core-) $(drivers-) $(net-) $(libs-) $(virt-))))
992 init-y := $(patsubst %/, %/built-in.a, $(init-y))
993 core-y := $(patsubst %/, %/built-in.a, $(core-y))
994 drivers-y := $(patsubst %/, %/built-in.a, $(drivers-y))
995 net-y := $(patsubst %/, %/built-in.a, $(net-y))
996 libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
997 libs-y2 := $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y)))
998 virt-y := $(patsubst %/, %/built-in.a, $(virt-y))
1000 # Externally visible symbols (used by link-vmlinux.sh)
1001 export KBUILD_VMLINUX_INIT := $(head-y) $(init-y)
1002 export KBUILD_VMLINUX_MAIN := $(core-y) $(libs-y2) $(drivers-y) $(net-y) $(virt-y)
1003 export KBUILD_VMLINUX_LIBS := $(libs-y1)
1004 export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
1005 export LDFLAGS_vmlinux
1006 # used by scripts/package/Makefile
1007 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools)
1009 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_INIT) $(KBUILD_VMLINUX_MAIN) $(KBUILD_VMLINUX_LIBS)
1011 # Recurse until adjust_autoksyms.sh is satisfied
1012 PHONY += autoksyms_recursive
1013 autoksyms_recursive: $(vmlinux-deps)
1014 ifdef CONFIG_TRIM_UNUSED_KSYMS
1015 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1016 "$(MAKE) -f $(srctree)/Makefile vmlinux"
1019 # For the kernel to actually contain only the needed exported symbols,
1020 # we have to build modules as well to determine what those symbols are.
1021 # (this can be evaluated only once include/config/auto.conf has been included)
1022 ifdef CONFIG_TRIM_UNUSED_KSYMS
1026 autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1029 $(Q)mkdir -p $(dir $@)
1032 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1034 # Final link of vmlinux with optional arch pass after final link
1035 cmd_link-vmlinux = \
1036 $(CONFIG_SHELL) $< $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) ; \
1037 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1039 vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1040 ifdef CONFIG_HEADERS_CHECK
1041 $(Q)$(MAKE) -f $(srctree)/Makefile headers_check
1043 ifdef CONFIG_GDB_SCRIPTS
1044 $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1046 +$(call if_changed,link-vmlinux)
1048 # Build samples along the rest of the kernel
1049 ifdef CONFIG_SAMPLES
1050 vmlinux-dirs += samples
1053 # The actual objects are generated when descending,
1054 # make sure no implicit rule kicks in
1055 $(sort $(vmlinux-deps)): $(vmlinux-dirs) ;
1057 # Handle descending into subdirectories listed in $(vmlinux-dirs)
1058 # Preset locale variables to speed up the build process. Limit locale
1059 # tweaks to this spot to avoid wrong language settings when running
1060 # make menuconfig etc.
1061 # Error messages still appears in the original language
1063 PHONY += $(vmlinux-dirs)
1064 $(vmlinux-dirs): prepare scripts
1065 $(Q)$(MAKE) $(build)=$@ need-builtin=1
1067 define filechk_kernel.release
1068 echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1071 # Store (new) KERNELRELEASE string in include/config/kernel.release
1072 include/config/kernel.release: include/config/auto.conf FORCE
1073 $(call filechk,kernel.release)
1075 # Additional helpers built in scripts/
1076 # Carefully list dependencies so we do not try to build scripts twice
1079 scripts: scripts_basic include/config/auto.conf include/config/tristate.conf \
1080 asm-generic gcc-plugins $(autoksyms_h)
1081 $(Q)$(MAKE) $(build)=$(@)
1083 # Things we need to do before we recursively start building the kernel
1084 # or the modules are listed in "prepare".
1085 # A multi level approach is used. prepareN is processed before prepareN-1.
1086 # archprepare is used in arch Makefiles and when processed asm symlink,
1087 # version.h and scripts_basic is processed / created.
1089 # Listed in dependency order
1090 PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3
1092 # prepare3 is used to check if we are building in a separate output directory,
1094 # 1) Check that make has not been executed in the kernel src $(srctree)
1095 prepare3: include/config/kernel.release
1096 ifneq ($(KBUILD_SRC),)
1097 @$(kecho) ' Using $(srctree) as source for kernel'
1098 $(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
1099 echo >&2 " $(srctree) is not clean, please run 'make mrproper'"; \
1100 echo >&2 " in the '$(srctree)' directory.";\
1105 # prepare2 creates a makefile if using a separate output directory.
1106 # From this point forward, .config has been reprocessed, so any rules
1107 # that need to depend on updated CONFIG_* values can be checked here.
1108 prepare2: prepare3 prepare-compiler-check outputmakefile asm-generic
1110 prepare1: prepare2 $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1111 include/config/auto.conf
1114 archprepare: archheaders archscripts prepare1 scripts_basic
1116 prepare0: archprepare gcc-plugins
1117 $(Q)$(MAKE) $(build)=.
1119 # All the preparing..
1120 prepare: prepare0 prepare-objtool
1122 # Support for using generic headers in asm-generic
1123 PHONY += asm-generic uapi-asm-generic
1124 asm-generic: uapi-asm-generic
1125 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
1126 src=asm obj=arch/$(SRCARCH)/include/generated/asm
1128 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
1129 src=uapi/asm obj=arch/$(SRCARCH)/include/generated/uapi/asm
1131 PHONY += prepare-objtool
1132 prepare-objtool: $(objtool_target)
1134 # Check for CONFIG flags that require compiler support. Abort the build
1135 # after .config has been processed, but before the kernel build starts.
1137 # For security-sensitive CONFIG options, we don't want to fallback and/or
1138 # silently change which compiler flags will be used, since that leads to
1139 # producing kernels with different security feature characteristics
1140 # depending on the compiler used. (For example, "But I selected
1141 # CC_STACKPROTECTOR_STRONG! Why did it build with _REGULAR?!")
1142 PHONY += prepare-compiler-check
1143 prepare-compiler-check: FORCE
1144 # Make sure compiler supports requested stack protector flag.
1146 # Warn about CONFIG_CC_STACKPROTECTOR_AUTO having found no option.
1147 ifeq ($(stackp-flag),)
1148 @echo CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1149 Compiler does not support any known stack-protector >&2
1151 # Fail if specifically requested stack protector is missing.
1152 ifeq ($(call cc-option, $(stackp-flag)),)
1153 @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1154 $(stackp-flag) not supported by compiler >&2 && exit 1
1158 # Make sure compiler does not have buggy stack-protector support. If a
1159 # specific stack-protector was requested, fail the build, otherwise warn.
1161 ifeq ($(stackp-name),AUTO)
1162 @echo CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1163 $(stackp-flag) available but compiler is broken: disabling >&2
1165 @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
1166 $(stackp-flag) available but compiler is broken >&2 && exit 1
1171 # Generate some files
1172 # ---------------------------------------------------------------------------
1174 # KERNELRELEASE can change from a few different places, meaning version.h
1175 # needs to be updated, so this check is forced on all builds
1178 define filechk_utsrelease.h
1179 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1180 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1183 (echo \#define UTS_RELEASE \"$(KERNELRELEASE)\";)
1186 define filechk_version.h
1187 (echo \#define LINUX_VERSION_CODE $(shell \
1188 expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
1189 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))';)
1192 $(version_h): $(srctree)/Makefile FORCE
1193 $(call filechk,version.h)
1194 $(Q)rm -f $(old_version_h)
1196 include/generated/utsrelease.h: include/config/kernel.release FORCE
1197 $(call filechk,utsrelease.h)
1201 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1202 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1204 # ---------------------------------------------------------------------------
1207 #Default location for installed headers
1208 export INSTALL_HDR_PATH = $(objtree)/usr
1210 # If we do an all arch process set dst to include/arch-$(SRCARCH)
1211 hdr-dst = $(if $(KBUILD_HEADERS), dst=include/arch-$(SRCARCH), dst=include)
1213 PHONY += archheaders
1216 PHONY += archscripts
1220 __headers: $(version_h) scripts_basic uapi-asm-generic archheaders archscripts
1221 $(Q)$(MAKE) $(build)=scripts build_unifdef
1223 PHONY += headers_install_all
1224 headers_install_all:
1225 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh install
1227 PHONY += headers_install
1228 headers_install: __headers
1229 $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1230 $(error Headers not exportable for the $(SRCARCH) architecture))
1231 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include
1232 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst)
1234 PHONY += headers_check_all
1235 headers_check_all: headers_install_all
1236 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh check
1238 PHONY += headers_check
1239 headers_check: headers_install
1240 $(Q)$(MAKE) $(hdr-inst)=include/uapi dst=include HDRCHECK=1
1241 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi $(hdr-dst) HDRCHECK=1
1243 # ---------------------------------------------------------------------------
1248 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1250 PHONY += kselftest-clean
1252 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests clean
1254 PHONY += kselftest-merge
1256 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1257 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \
1258 -m $(objtree)/.config \
1259 $(srctree)/tools/testing/selftests/*/config
1260 +$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1262 # ---------------------------------------------------------------------------
1265 ifdef CONFIG_MODULES
1267 # By default, build modules as well
1273 # A module can be listed more than once in obj-m resulting in
1274 # duplicate lines in modules.order files. Those are removed
1275 # using awk while concatenating to the final file.
1278 modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
1279 $(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
1280 @$(kecho) ' Building modules, stage 2.';
1281 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1283 modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
1284 $(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
1286 %/modules.builtin: include/config/auto.conf
1287 $(Q)$(MAKE) $(modbuiltin)=$*
1290 # Target to prepare building external modules
1291 PHONY += modules_prepare
1292 modules_prepare: prepare scripts
1294 # Target to install modules
1295 PHONY += modules_install
1296 modules_install: _modinst_ _modinst_post
1300 @rm -rf $(MODLIB)/kernel
1301 @rm -f $(MODLIB)/source
1302 @mkdir -p $(MODLIB)/kernel
1303 @ln -s $(abspath $(srctree)) $(MODLIB)/source
1304 @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
1305 rm -f $(MODLIB)/build ; \
1306 ln -s $(CURDIR) $(MODLIB)/build ; \
1308 @cp -f $(objtree)/modules.order $(MODLIB)/
1309 @cp -f $(objtree)/modules.builtin $(MODLIB)/
1310 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1312 # This depmod is only for convenience to give the initial
1313 # boot a modules.dep even before / is mounted read-write. However the
1314 # boot script depmod is the master version.
1315 PHONY += _modinst_post
1316 _modinst_post: _modinst_
1319 ifeq ($(CONFIG_MODULE_SIG), y)
1320 PHONY += modules_sign
1322 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1325 else # CONFIG_MODULES
1327 # Modules not configured
1328 # ---------------------------------------------------------------------------
1330 PHONY += modules modules_install
1331 modules modules_install:
1333 @echo >&2 "The present kernel configuration has modules disabled."
1334 @echo >&2 "Type 'make config' and enable loadable module support."
1335 @echo >&2 "Then build a kernel with module support enabled."
1339 endif # CONFIG_MODULES
1342 # Cleaning is done on three levels.
1343 # make clean Delete most generated files
1344 # Leave enough to build external modules
1345 # make mrproper Delete the current configuration, and all generated files
1346 # make distclean Remove editor backup files, patch leftover files and the like
1348 # Directories & files removed with 'make clean'
1349 CLEAN_DIRS += $(MODVERDIR) include/ksym
1351 # Directories & files removed with 'make mrproper'
1352 MRPROPER_DIRS += include/config usr/include include/generated \
1353 arch/*/include/generated .tmp_objdiff
1354 MRPROPER_FILES += .config .config.old .version \
1355 Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
1356 signing_key.pem signing_key.priv signing_key.x509 \
1357 x509.genkey extra_certificates signing_key.x509.keyid \
1358 signing_key.x509.signer vmlinux-gdb.py
1360 # clean - Delete most, but leave enough to build external modules
1362 clean: rm-dirs := $(CLEAN_DIRS)
1363 clean: rm-files := $(CLEAN_FILES)
1364 clean-dirs := $(addprefix _clean_, . $(vmlinux-alldirs) Documentation samples)
1366 PHONY += $(clean-dirs) clean archclean vmlinuxclean
1368 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1371 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1372 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1374 clean: archclean vmlinuxclean
1376 # mrproper - Delete all generated files, including .config
1378 mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS))
1379 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1380 mrproper-dirs := $(addprefix _mrproper_,scripts)
1382 PHONY += $(mrproper-dirs) mrproper archmrproper
1384 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1386 mrproper: clean archmrproper $(mrproper-dirs)
1395 @find $(srctree) $(RCS_FIND_IGNORE) \
1396 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1397 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1398 -o -name 'core' \) \
1399 -type f -print | xargs rm -f
1402 # Packaging of the kernel to various formats
1403 # ---------------------------------------------------------------------------
1404 # rpm target kept for backward compatibility
1405 package-dir := scripts/package
1408 $(Q)$(MAKE) $(build)=$(package-dir) $@
1409 %pkg: include/config/kernel.release FORCE
1410 $(Q)$(MAKE) $(build)=$(package-dir) $@
1412 @echo " WARNING: \"rpm\" target will be removed after Linux 4.18"
1413 @echo " Please use \"rpm-pkg\" instead."
1416 # Brief documentation of the typical targets used
1417 # ---------------------------------------------------------------------------
1419 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1420 boards := $(sort $(notdir $(boards)))
1421 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1422 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1426 @echo 'Cleaning targets:'
1427 @echo ' clean - Remove most generated files but keep the config and'
1428 @echo ' enough build support to build external modules'
1429 @echo ' mrproper - Remove all generated files + config + various backup files'
1430 @echo ' distclean - mrproper + remove editor backup and patch files'
1432 @echo 'Configuration targets:'
1433 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1435 @echo 'Other generic targets:'
1436 @echo ' all - Build all targets marked with [*]'
1437 @echo '* vmlinux - Build the bare kernel'
1438 @echo '* modules - Build all modules'
1439 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1440 @echo ' dir/ - Build all files in dir and below'
1441 @echo ' dir/file.[ois] - Build specified target only'
1442 @echo ' dir/file.ll - Build the LLVM assembly file'
1443 @echo ' (requires compiler support for LLVM assembly generation)'
1444 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1445 @echo ' (requires a recent binutils and recent build (System.map))'
1446 @echo ' dir/file.ko - Build module including final link'
1447 @echo ' modules_prepare - Set up for building external modules'
1448 @echo ' tags/TAGS - Generate tags file for editors'
1449 @echo ' cscope - Generate cscope index'
1450 @echo ' gtags - Generate GNU GLOBAL index'
1451 @echo ' kernelrelease - Output the release version string (use with make -s)'
1452 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1453 @echo ' image_name - Output the image name (use with make -s)'
1454 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1455 echo ' (default: $(INSTALL_HDR_PATH))'; \
1457 @echo 'Static analysers:'
1458 @echo ' checkstack - Generate a list of stack hogs'
1459 @echo ' namespacecheck - Name space analysis on compiled kernel'
1460 @echo ' versioncheck - Sanity check on version.h usage'
1461 @echo ' includecheck - Check for duplicate included header files'
1462 @echo ' export_report - List the usages of all exported symbols'
1463 @echo ' headers_check - Sanity check on exported headers'
1464 @echo ' headerdep - Detect inclusion cycles in headers'
1465 @echo ' coccicheck - Check with Coccinelle'
1467 @echo 'Kernel selftest:'
1468 @echo ' kselftest - Build and run kernel selftest (run as root)'
1469 @echo ' Build, install, and boot kernel before'
1470 @echo ' running kselftest on it'
1471 @echo ' kselftest-clean - Remove all generated kselftest files'
1472 @echo ' kselftest-merge - Merge all the config dependencies of kselftest to existing'
1475 @echo 'Userspace tools targets:'
1476 @echo ' use "make tools/help"'
1477 @echo ' or "cd tools; make help"'
1479 @echo 'Kernel packaging:'
1480 @$(MAKE) $(build)=$(package-dir) help
1482 @echo 'Documentation targets:'
1483 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1485 @echo 'Architecture specific targets ($(SRCARCH)):'
1486 @$(if $(archhelp),$(archhelp),\
1487 echo ' No architecture specific help defined for $(SRCARCH)')
1490 $(foreach b, $(boards), \
1491 printf " %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1493 @$(if $(board-dirs), \
1494 $(foreach b, $(board-dirs), \
1495 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1496 printf " %-16s - Show all of the above\\n" help-boards; \
1499 @echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1500 @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
1501 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1502 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK (sparse by default)'
1503 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1504 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1505 @echo ' make W=n [targets] Enable extra gcc checks, n=1,2,3 where'
1506 @echo ' 1: warnings which may be relevant and do not occur too often'
1507 @echo ' 2: warnings which occur quite often but may still be relevant'
1508 @echo ' 3: more obscure warnings, can most likely be ignored'
1509 @echo ' Multiple levels can be combined with W=12 or W=123'
1511 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1512 @echo 'For further info see the ./README file'
1515 help-board-dirs := $(addprefix help-,$(board-dirs))
1517 help-boards: $(help-board-dirs)
1519 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1521 $(help-board-dirs): help-%:
1522 @echo 'Architecture specific targets ($(SRCARCH) $*):'
1523 @$(if $(boards-per-dir), \
1524 $(foreach b, $(boards-per-dir), \
1525 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1529 # Documentation targets
1530 # ---------------------------------------------------------------------------
1531 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1532 linkcheckdocs dochelp refcheckdocs
1533 PHONY += $(DOC_TARGETS)
1534 $(DOC_TARGETS): scripts_basic FORCE
1535 $(Q)$(MAKE) $(build)=Documentation $@
1537 else # KBUILD_EXTMOD
1540 # External module support.
1541 # When building external modules the kernel used as basis is considered
1542 # read-only, and no consistency checks are made and the make
1543 # system is not used on the basis kernel. If updates are required
1544 # in the basis kernel ordinary make commands (without M=...) must
1547 # The following are the only valid targets when building external
1549 # make M=dir clean Delete all automatically generated files
1550 # make M=dir modules Make all modules in specified dir
1551 # make M=dir Same as 'make M=dir modules'
1552 # make M=dir modules_install
1553 # Install the modules built in the module directory
1554 # Assumes install directory is already created
1556 # We are always building modules
1558 PHONY += crmodverdir
1562 PHONY += $(objtree)/Module.symvers
1563 $(objtree)/Module.symvers:
1564 @test -e $(objtree)/Module.symvers || ( \
1566 echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1567 echo " is missing; modules will have no dependencies and modversions."; \
1570 module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
1571 PHONY += $(module-dirs) modules
1572 $(module-dirs): crmodverdir $(objtree)/Module.symvers
1573 $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
1575 modules: $(module-dirs)
1576 @$(kecho) ' Building modules, stage 2.';
1577 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1579 PHONY += modules_install
1580 modules_install: _emodinst_ _emodinst_post
1582 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1585 $(Q)mkdir -p $(MODLIB)/$(install-dir)
1586 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1588 PHONY += _emodinst_post
1589 _emodinst_post: _emodinst_
1592 clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))
1594 PHONY += $(clean-dirs) clean
1596 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1598 clean: rm-dirs := $(MODVERDIR)
1599 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1603 @echo ' Building external modules.'
1604 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1606 @echo ' modules - default target, build the module(s)'
1607 @echo ' modules_install - install the module'
1608 @echo ' clean - remove generated files in module directory only'
1612 PHONY += prepare scripts
1615 endif # KBUILD_EXTMOD
1617 clean: $(clean-dirs)
1620 @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1621 \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1622 -o -name '*.ko.*' -o -name '*.dtb' -o -name '*.dtb.S' \
1623 -o -name '*.dwo' -o -name '*.lst' \
1625 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1626 -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1627 -o -name '*.asn1.[ch]' \
1628 -o -name '*.symtypes' -o -name 'modules.order' \
1629 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1630 -o -name .cache.mk \
1631 -o -name '*.c.[012]*.*' \
1633 -o -name '*.gcno' \) -type f -print | xargs rm -f
1635 # Generate tags for editors
1636 # ---------------------------------------------------------------------------
1637 quiet_cmd_tags = GEN $@
1638 cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
1640 tags TAGS cscope gtags: FORCE
1643 # Scripts to check various things for consistency
1644 # ---------------------------------------------------------------------------
1646 PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1649 find $(srctree)/* $(RCS_FIND_IGNORE) \
1650 -name '*.[hcS]' -type f -print | sort \
1651 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1654 find $(srctree)/* $(RCS_FIND_IGNORE) \
1655 -name '*.[hcS]' -type f -print | sort \
1656 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1659 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1662 $(PERL) $(srctree)/scripts/namespace.pl
1665 $(PERL) $(srctree)/scripts/export_report.pl
1667 endif #ifeq ($(config-targets),1)
1668 endif #ifeq ($(mixed-targets),1)
1670 PHONY += checkstack kernelrelease kernelversion image_name
1672 # UML needs a little special treatment here. It wants to use the host
1673 # toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
1674 # else wants $(ARCH), including people doing cross-builds, which means
1675 # that $(SUBARCH) doesn't work here.
1677 CHECKSTACK_ARCH := $(SUBARCH)
1679 CHECKSTACK_ARCH := $(ARCH)
1682 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1683 $(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1686 @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1689 @echo $(KERNELVERSION)
1692 @echo $(KBUILD_IMAGE)
1694 # Clear a bunch of variables before executing the submake
1696 $(Q)mkdir -p $(objtree)/tools
1697 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/
1700 $(Q)mkdir -p $(objtree)/tools
1701 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/ $*
1704 # ---------------------------------------------------------------------------
1705 # Single targets are compatible with:
1706 # - build with mixed source and output
1707 # - build with separate output dir 'make O=...'
1708 # - external modules
1710 # target-dir => where to store outputfile
1711 # build-dir => directory in kernel source tree to use
1713 ifeq ($(KBUILD_EXTMOD),)
1714 build-dir = $(patsubst %/,%,$(dir $@))
1715 target-dir = $(dir $@)
1717 zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
1718 build-dir = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
1719 target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@))
1722 %.s: %.c prepare scripts FORCE
1723 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1724 %.i: %.c prepare scripts FORCE
1725 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1726 %.o: %.c prepare scripts FORCE
1727 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1728 %.lst: %.c prepare scripts FORCE
1729 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1730 %.s: %.S prepare scripts FORCE
1731 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1732 %.o: %.S prepare scripts FORCE
1733 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1734 %.symtypes: %.c prepare scripts FORCE
1735 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1736 %.ll: %.c prepare scripts FORCE
1737 $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1740 /: prepare scripts FORCE
1742 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1743 $(build)=$(build-dir)
1744 # Make sure the latest headers are built for Documentation
1745 Documentation/ samples/: headers_install
1746 %/: prepare scripts FORCE
1748 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1749 $(build)=$(build-dir)
1750 %.ko: prepare scripts FORCE
1752 $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1753 $(build)=$(build-dir) $(@:.ko=.o)
1754 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1756 # FIXME Should go into a make.lib or something
1757 # ===========================================================================
1759 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs)))
1760 cmd_rmdirs = rm -rf $(rm-dirs)
1762 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
1763 cmd_rmfiles = rm -f $(rm-files)
1765 # Run depmod only if we have System.map and depmod is executable
1766 quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
1767 cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1770 # Create temporary dir for module support files
1771 # clean it up only when building all modules
1772 cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
1773 $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
1775 # read all saved command lines
1777 cmd_files := $(wildcard .*.cmd $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd))
1779 ifneq ($(cmd_files),)
1780 $(cmd_files): ; # Do not try to update included dependency files
1781 include $(cmd_files)
1784 endif # skip-makefile
1789 # Declare the contents of the .PHONY variable as phony. We keep that
1790 # information in a variable so we can use it in if_changed and friends.