xref: /openbmc/linux/Makefile (revision 808643ea)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 5
3PATCHLEVEL = 14
4SUBLEVEL = 0
5EXTRAVERSION = -rc3
6NAME = Opossums on Parade
7
8# *DOCUMENTATION*
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.
13
14$(if $(filter __%, $(MAKECMDGOALS)), \
15	$(error targets prefixed with '__' are only for internal use))
16
17# That's our default target when none is given on the command line
18PHONY := __all
19__all:
20
21# We are using a recursive build, so we need to do a little thinking
22# to get the ordering right.
23#
24# Most importantly: sub-Makefiles should only ever modify files in
25# their own directory. If in some directory we have a dependency on
26# a file in another dir (which doesn't happen often, but it's often
27# unavoidable when linking the built-in.a targets which finally
28# turn into vmlinux), we will call a sub make in that other dir, and
29# after that we are sure that everything which is in that other dir
30# is now up to date.
31#
32# The only cases where we need to modify files which have global
33# effects are thus separated out and done before the recursive
34# descending is started. They are now explicitly listed as the
35# prepare rule.
36
37ifneq ($(sub_make_done),1)
38
39# Do not use make's built-in rules and variables
40# (this increases performance and avoids hard-to-debug behaviour)
41MAKEFLAGS += -rR
42
43# Avoid funny character set dependencies
44unexport LC_ALL
45LC_COLLATE=C
46LC_NUMERIC=C
47export LC_COLLATE LC_NUMERIC
48
49# Avoid interference with shell env settings
50unexport GREP_OPTIONS
51
52# Beautify output
53# ---------------------------------------------------------------------------
54#
55# Normally, we echo the whole command before executing it. By making
56# that echo $($(quiet)$(cmd)), we now have the possibility to set
57# $(quiet) to choose other forms of output instead, e.g.
58#
59#         quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
60#         cmd_cc_o_c       = $(CC) $(c_flags) -c -o $@ $<
61#
62# If $(quiet) is empty, the whole command will be printed.
63# If it is set to "quiet_", only the short version will be printed.
64# If it is set to "silent_", nothing will be printed at all, since
65# the variable $(silent_cmd_cc_o_c) doesn't exist.
66#
67# A simple variant is to prefix commands with $(Q) - that's useful
68# for commands that shall be hidden in non-verbose mode.
69#
70#	$(Q)ln $@ :<
71#
72# If KBUILD_VERBOSE equals 0 then the above command will be hidden.
73# If KBUILD_VERBOSE equals 1 then the above command is displayed.
74# If KBUILD_VERBOSE equals 2 then give the reason why each target is rebuilt.
75#
76# To put more focus on warnings, be less verbose as default
77# Use 'make V=1' to see the full commands
78
79ifeq ("$(origin V)", "command line")
80  KBUILD_VERBOSE = $(V)
81endif
82ifndef KBUILD_VERBOSE
83  KBUILD_VERBOSE = 0
84endif
85
86ifeq ($(KBUILD_VERBOSE),1)
87  quiet =
88  Q =
89else
90  quiet=quiet_
91  Q = @
92endif
93
94# If the user is running make -s (silent mode), suppress echoing of
95# commands
96
97ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
98  quiet=silent_
99  KBUILD_VERBOSE = 0
100endif
101
102export quiet Q KBUILD_VERBOSE
103
104# Call a source code checker (by default, "sparse") as part of the
105# C compilation.
106#
107# Use 'make C=1' to enable checking of only re-compiled files.
108# Use 'make C=2' to enable checking of *all* source files, regardless
109# of whether they are re-compiled or not.
110#
111# See the file "Documentation/dev-tools/sparse.rst" for more details,
112# including where to get the "sparse" utility.
113
114ifeq ("$(origin C)", "command line")
115  KBUILD_CHECKSRC = $(C)
116endif
117ifndef KBUILD_CHECKSRC
118  KBUILD_CHECKSRC = 0
119endif
120
121export KBUILD_CHECKSRC
122
123# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
124# directory of external module to build. Setting M= takes precedence.
125ifeq ("$(origin M)", "command line")
126  KBUILD_EXTMOD := $(M)
127endif
128
129$(if $(word 2, $(KBUILD_EXTMOD)), \
130	$(error building multiple external modules is not supported))
131
132# Remove trailing slashes
133ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
134KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
135endif
136
137export KBUILD_EXTMOD
138
139# Kbuild will save output files in the current working directory.
140# This does not need to match to the root of the kernel source tree.
141#
142# For example, you can do this:
143#
144#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
145#
146# If you want to save output files in a different location, there are
147# two syntaxes to specify it.
148#
149# 1) O=
150# Use "make O=dir/to/store/output/files/"
151#
152# 2) Set KBUILD_OUTPUT
153# Set the environment variable KBUILD_OUTPUT to point to the output directory.
154# export KBUILD_OUTPUT=dir/to/store/output/files/; make
155#
156# The O= assignment takes precedence over the KBUILD_OUTPUT environment
157# variable.
158
159# Do we want to change the working directory?
160ifeq ("$(origin O)", "command line")
161  KBUILD_OUTPUT := $(O)
162endif
163
164ifneq ($(KBUILD_OUTPUT),)
165# Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
166# expand a shell special character '~'. We use a somewhat tedious way here.
167abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
168$(if $(abs_objtree),, \
169     $(error failed to create output directory "$(KBUILD_OUTPUT)"))
170
171# $(realpath ...) resolves symlinks
172abs_objtree := $(realpath $(abs_objtree))
173else
174abs_objtree := $(CURDIR)
175endif # ifneq ($(KBUILD_OUTPUT),)
176
177ifeq ($(abs_objtree),$(CURDIR))
178# Suppress "Entering directory ..." unless we are changing the work directory.
179MAKEFLAGS += --no-print-directory
180else
181need-sub-make := 1
182endif
183
184this-makefile := $(lastword $(MAKEFILE_LIST))
185abs_srctree := $(realpath $(dir $(this-makefile)))
186
187ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
188$(error source directory cannot contain spaces or colons)
189endif
190
191ifneq ($(abs_srctree),$(abs_objtree))
192# Look for make include files relative to root of kernel src
193#
194# This does not become effective immediately because MAKEFLAGS is re-parsed
195# once after the Makefile is read. We need to invoke sub-make.
196MAKEFLAGS += --include-dir=$(abs_srctree)
197need-sub-make := 1
198endif
199
200ifneq ($(filter 3.%,$(MAKE_VERSION)),)
201# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
202# We need to invoke sub-make to avoid implicit rules in the top Makefile.
203need-sub-make := 1
204# Cancel implicit rules for this Makefile.
205$(this-makefile): ;
206endif
207
208export abs_srctree abs_objtree
209export sub_make_done := 1
210
211ifeq ($(need-sub-make),1)
212
213PHONY += $(MAKECMDGOALS) __sub-make
214
215$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
216	@:
217
218# Invoke a second make in the output directory, passing relevant variables
219__sub-make:
220	$(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
221
222endif # need-sub-make
223endif # sub_make_done
224
225# We process the rest of the Makefile if this is the final invocation of make
226ifeq ($(need-sub-make),)
227
228# Do not print "Entering directory ...",
229# but we want to display it when entering to the output directory
230# so that IDEs/editors are able to understand relative filenames.
231MAKEFLAGS += --no-print-directory
232
233ifeq ($(abs_srctree),$(abs_objtree))
234        # building in the source tree
235        srctree := .
236	building_out_of_srctree :=
237else
238        ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
239                # building in a subdirectory of the source tree
240                srctree := ..
241        else
242                srctree := $(abs_srctree)
243        endif
244	building_out_of_srctree := 1
245endif
246
247ifneq ($(KBUILD_ABS_SRCTREE),)
248srctree := $(abs_srctree)
249endif
250
251objtree		:= .
252VPATH		:= $(srctree)
253
254export building_out_of_srctree srctree objtree VPATH
255
256# To make sure we do not include .config for any of the *config targets
257# catch them early, and hand them over to scripts/kconfig/Makefile
258# It is allowed to specify more targets when calling make, including
259# mixing *config targets and build targets.
260# For example 'make oldconfig all'.
261# Detect when mixed targets is specified, and make a second invocation
262# of make so .config is not included in this case either (for *config).
263
264version_h := include/generated/uapi/linux/version.h
265
266clean-targets := %clean mrproper cleandocs
267no-dot-config-targets := $(clean-targets) \
268			 cscope gtags TAGS tags help% %docs check% coccicheck \
269			 $(version_h) headers headers_% archheaders archscripts \
270			 %asm-generic kernelversion %src-pkg dt_binding_check \
271			 outputmakefile
272# Installation targets should not require compiler. Unfortunately, vdso_install
273# is an exception where build artifacts may be updated. This must be fixed.
274no-compiler-targets := $(no-dot-config-targets) install dtbs_install \
275			headers_install modules_install kernelrelease image_name
276no-sync-config-targets := $(no-dot-config-targets) %install kernelrelease \
277			  image_name
278single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/
279
280config-build	:=
281mixed-build	:=
282need-config	:= 1
283need-compiler	:= 1
284may-sync-config	:= 1
285single-build	:=
286
287ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
288	ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
289		need-config :=
290	endif
291endif
292
293ifneq ($(filter $(no-compiler-targets), $(MAKECMDGOALS)),)
294	ifeq ($(filter-out $(no-compiler-targets), $(MAKECMDGOALS)),)
295		need-compiler :=
296	endif
297endif
298
299ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
300	ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
301		may-sync-config :=
302	endif
303endif
304
305ifneq ($(KBUILD_EXTMOD),)
306	may-sync-config :=
307endif
308
309ifeq ($(KBUILD_EXTMOD),)
310        ifneq ($(filter %config,$(MAKECMDGOALS)),)
311		config-build := 1
312                ifneq ($(words $(MAKECMDGOALS)),1)
313			mixed-build := 1
314                endif
315        endif
316endif
317
318# We cannot build single targets and the others at the same time
319ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
320	single-build := 1
321	ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
322		mixed-build := 1
323	endif
324endif
325
326# For "make -j clean all", "make -j mrproper defconfig all", etc.
327ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
328        ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
329		mixed-build := 1
330        endif
331endif
332
333# install and modules_install need also be processed one by one
334ifneq ($(filter install,$(MAKECMDGOALS)),)
335        ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
336		mixed-build := 1
337        endif
338endif
339
340ifdef mixed-build
341# ===========================================================================
342# We're called with mixed targets (*config and build targets).
343# Handle them one by one.
344
345PHONY += $(MAKECMDGOALS) __build_one_by_one
346
347$(MAKECMDGOALS): __build_one_by_one
348	@:
349
350__build_one_by_one:
351	$(Q)set -e; \
352	for i in $(MAKECMDGOALS); do \
353		$(MAKE) -f $(srctree)/Makefile $$i; \
354	done
355
356else # !mixed-build
357
358include $(srctree)/scripts/Kbuild.include
359
360# Read KERNELRELEASE from include/config/kernel.release (if it exists)
361KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
362KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
363export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
364
365include $(srctree)/scripts/subarch.include
366
367# Cross compiling and selecting different set of gcc/bin-utils
368# ---------------------------------------------------------------------------
369#
370# When performing cross compilation for other architectures ARCH shall be set
371# to the target architecture. (See arch/* for the possibilities).
372# ARCH can be set during invocation of make:
373# make ARCH=ia64
374# Another way is to have ARCH set in the environment.
375# The default ARCH is the host where make is executed.
376
377# CROSS_COMPILE specify the prefix used for all executables used
378# during compilation. Only gcc and related bin-utils executables
379# are prefixed with $(CROSS_COMPILE).
380# CROSS_COMPILE can be set on the command line
381# make CROSS_COMPILE=ia64-linux-
382# Alternatively CROSS_COMPILE can be set in the environment.
383# Default value for CROSS_COMPILE is not to prefix executables
384# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
385ARCH		?= $(SUBARCH)
386
387# Architecture as present in compile.h
388UTS_MACHINE 	:= $(ARCH)
389SRCARCH 	:= $(ARCH)
390
391# Additional ARCH settings for x86
392ifeq ($(ARCH),i386)
393        SRCARCH := x86
394endif
395ifeq ($(ARCH),x86_64)
396        SRCARCH := x86
397endif
398
399# Additional ARCH settings for sparc
400ifeq ($(ARCH),sparc32)
401       SRCARCH := sparc
402endif
403ifeq ($(ARCH),sparc64)
404       SRCARCH := sparc
405endif
406
407export cross_compiling :=
408ifneq ($(SRCARCH),$(SUBARCH))
409cross_compiling := 1
410endif
411
412KCONFIG_CONFIG	?= .config
413export KCONFIG_CONFIG
414
415# SHELL used by kbuild
416CONFIG_SHELL := sh
417
418HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
419HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
420HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
421
422ifneq ($(LLVM),)
423HOSTCC	= clang
424HOSTCXX	= clang++
425else
426HOSTCC	= gcc
427HOSTCXX	= g++
428endif
429
430export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
431			      -O2 -fomit-frame-pointer -std=gnu89
432export KBUILD_USERLDFLAGS :=
433
434KBUILD_HOSTCFLAGS   := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
435KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
436KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
437KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
438
439# Make variables (CC, etc...)
440CPP		= $(CC) -E
441ifneq ($(LLVM),)
442CC		= clang
443LD		= ld.lld
444AR		= llvm-ar
445NM		= llvm-nm
446OBJCOPY		= llvm-objcopy
447OBJDUMP		= llvm-objdump
448READELF		= llvm-readelf
449STRIP		= llvm-strip
450else
451CC		= $(CROSS_COMPILE)gcc
452LD		= $(CROSS_COMPILE)ld
453AR		= $(CROSS_COMPILE)ar
454NM		= $(CROSS_COMPILE)nm
455OBJCOPY		= $(CROSS_COMPILE)objcopy
456OBJDUMP		= $(CROSS_COMPILE)objdump
457READELF		= $(CROSS_COMPILE)readelf
458STRIP		= $(CROSS_COMPILE)strip
459endif
460PAHOLE		= pahole
461RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
462LEX		= flex
463YACC		= bison
464AWK		= awk
465INSTALLKERNEL  := installkernel
466DEPMOD		= depmod
467PERL		= perl
468PYTHON3		= python3
469CHECK		= sparse
470BASH		= bash
471KGZIP		= gzip
472KBZIP2		= bzip2
473KLZOP		= lzop
474LZMA		= lzma
475LZ4		= lz4c
476XZ		= xz
477ZSTD		= zstd
478
479CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
480		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
481NOSTDINC_FLAGS :=
482CFLAGS_MODULE   =
483AFLAGS_MODULE   =
484LDFLAGS_MODULE  =
485CFLAGS_KERNEL	=
486AFLAGS_KERNEL	=
487LDFLAGS_vmlinux =
488
489# Use USERINCLUDE when you must reference the UAPI directories only.
490USERINCLUDE    := \
491		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
492		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
493		-I$(srctree)/include/uapi \
494		-I$(objtree)/include/generated/uapi \
495                -include $(srctree)/include/linux/compiler-version.h \
496                -include $(srctree)/include/linux/kconfig.h
497
498# Use LINUXINCLUDE when you must reference the include/ directory.
499# Needed to be compatible with the O= option
500LINUXINCLUDE    := \
501		-I$(srctree)/arch/$(SRCARCH)/include \
502		-I$(objtree)/arch/$(SRCARCH)/include/generated \
503		$(if $(building_out_of_srctree),-I$(srctree)/include) \
504		-I$(objtree)/include \
505		$(USERINCLUDE)
506
507KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
508KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
509		   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
510		   -Werror=implicit-function-declaration -Werror=implicit-int \
511		   -Werror=return-type -Wno-format-security \
512		   -std=gnu89
513KBUILD_CPPFLAGS := -D__KERNEL__
514KBUILD_AFLAGS_KERNEL :=
515KBUILD_CFLAGS_KERNEL :=
516KBUILD_AFLAGS_MODULE  := -DMODULE
517KBUILD_CFLAGS_MODULE  := -DMODULE
518KBUILD_LDFLAGS_MODULE :=
519KBUILD_LDFLAGS :=
520CLANG_FLAGS :=
521
522export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC
523export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
524export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
525export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
526export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
527
528export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
529export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
530export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
531export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
532export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
533
534# Files to ignore in find ... statements
535
536export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
537			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
538			  -prune -o
539export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
540			 --exclude CVS --exclude .pc --exclude .hg --exclude .git
541
542# ===========================================================================
543# Rules shared between *config targets and build targets
544
545# Basic helpers built in scripts/basic/
546PHONY += scripts_basic
547scripts_basic:
548	$(Q)$(MAKE) $(build)=scripts/basic
549	$(Q)rm -f .tmp_quiet_recordmcount
550
551PHONY += outputmakefile
552ifdef building_out_of_srctree
553# Before starting out-of-tree build, make sure the source tree is clean.
554# outputmakefile generates a Makefile in the output directory, if using a
555# separate output directory. This allows convenient use of make in the
556# output directory.
557# At the same time when output Makefile generated, generate .gitignore to
558# ignore whole output directory
559
560quiet_cmd_makefile = GEN     Makefile
561      cmd_makefile = { \
562	echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
563	echo "include $(srctree)/Makefile"; \
564	} > Makefile
565
566outputmakefile:
567	$(Q)if [ -f $(srctree)/.config -o \
568		 -d $(srctree)/include/config -o \
569		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
570		echo >&2 "***"; \
571		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
572		echo >&2 "*** in $(abs_srctree)";\
573		echo >&2 "***"; \
574		false; \
575	fi
576	$(Q)ln -fsn $(srctree) source
577	$(call cmd,makefile)
578	$(Q)test -e .gitignore || \
579	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
580endif
581
582# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
583# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
584# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
585# and from include/config/auto.conf.cmd to detect the compiler upgrade.
586CC_VERSION_TEXT = $(subst $(pound),,$(shell $(CC) --version 2>/dev/null | head -n 1))
587
588ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
589ifneq ($(CROSS_COMPILE),)
590CLANG_FLAGS	+= --target=$(notdir $(CROSS_COMPILE:%-=%))
591endif
592ifeq ($(LLVM_IAS),1)
593CLANG_FLAGS	+= -integrated-as
594else
595CLANG_FLAGS	+= -no-integrated-as
596GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
597CLANG_FLAGS	+= --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE))
598endif
599CLANG_FLAGS	+= -Werror=unknown-warning-option
600KBUILD_CFLAGS	+= $(CLANG_FLAGS)
601KBUILD_AFLAGS	+= $(CLANG_FLAGS)
602export CLANG_FLAGS
603endif
604
605# Include this also for config targets because some architectures need
606# cc-cross-prefix to determine CROSS_COMPILE.
607ifdef need-compiler
608include $(srctree)/scripts/Makefile.compiler
609endif
610
611ifdef config-build
612# ===========================================================================
613# *config targets only - make sure prerequisites are updated, and descend
614# in scripts/kconfig to make the *config target
615
616# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
617# KBUILD_DEFCONFIG may point out an alternative default configuration
618# used for 'make defconfig'
619include $(srctree)/arch/$(SRCARCH)/Makefile
620export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
621
622config: outputmakefile scripts_basic FORCE
623	$(Q)$(MAKE) $(build)=scripts/kconfig $@
624
625%config: outputmakefile scripts_basic FORCE
626	$(Q)$(MAKE) $(build)=scripts/kconfig $@
627
628else #!config-build
629# ===========================================================================
630# Build targets only - this includes vmlinux, arch specific targets, clean
631# targets and others. In general all targets except *config targets.
632
633# If building an external module we do not care about the all: rule
634# but instead __all depend on modules
635PHONY += all
636ifeq ($(KBUILD_EXTMOD),)
637__all: all
638else
639__all: modules
640endif
641
642# Decide whether to build built-in, modular, or both.
643# Normally, just do built-in.
644
645KBUILD_MODULES :=
646KBUILD_BUILTIN := 1
647
648# If we have only "make modules", don't compile built-in objects.
649ifeq ($(MAKECMDGOALS),modules)
650  KBUILD_BUILTIN :=
651endif
652
653# If we have "make <whatever> modules", compile modules
654# in addition to whatever we do anyway.
655# Just "make" or "make all" shall build modules as well
656
657ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
658  KBUILD_MODULES := 1
659endif
660
661ifeq ($(MAKECMDGOALS),)
662  KBUILD_MODULES := 1
663endif
664
665export KBUILD_MODULES KBUILD_BUILTIN
666
667ifdef need-config
668include include/config/auto.conf
669endif
670
671ifeq ($(KBUILD_EXTMOD),)
672# Objects we will link into vmlinux / subdirs we need to visit
673core-y		:= init/ usr/ arch/$(SRCARCH)/
674drivers-y	:= drivers/ sound/
675drivers-$(CONFIG_SAMPLES) += samples/
676drivers-$(CONFIG_NET) += net/
677drivers-y	+= virt/
678libs-y		:= lib/
679endif # KBUILD_EXTMOD
680
681# The all: target is the default when no target is given on the
682# command line.
683# This allow a user to issue only 'make' to build a kernel including modules
684# Defaults to vmlinux, but the arch makefile usually adds further targets
685all: vmlinux
686
687CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage \
688	$(call cc-option,-fno-tree-loop-im) \
689	$(call cc-disable-warning,maybe-uninitialized,)
690export CFLAGS_GCOV
691
692# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
693ifdef CONFIG_FUNCTION_TRACER
694  CC_FLAGS_FTRACE := -pg
695endif
696
697RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
698RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
699RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
700RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
701RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
702RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
703export RETPOLINE_CFLAGS
704export RETPOLINE_VDSO_CFLAGS
705
706include $(srctree)/arch/$(SRCARCH)/Makefile
707
708ifdef need-config
709ifdef may-sync-config
710# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
711# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
712# because some architectures define CROSS_COMPILE there.
713include include/config/auto.conf.cmd
714
715$(KCONFIG_CONFIG):
716	@echo >&2 '***'
717	@echo >&2 '*** Configuration file "$@" not found!'
718	@echo >&2 '***'
719	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
720	@echo >&2 '*** "make menuconfig" or "make xconfig").'
721	@echo >&2 '***'
722	@/bin/false
723
724# The actual configuration files used during the build are stored in
725# include/generated/ and include/config/. Update them if .config is newer than
726# include/config/auto.conf (which mirrors .config).
727#
728# This exploits the 'multi-target pattern rule' trick.
729# The syncconfig should be executed only once to make all the targets.
730# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
731#
732# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
733# so you cannot notice that Kconfig is waiting for the user input.
734%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h: $(KCONFIG_CONFIG)
735	$(Q)$(kecho) "  SYNC    $@"
736	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
737else # !may-sync-config
738# External modules and some install targets need include/generated/autoconf.h
739# and include/config/auto.conf but do not care if they are up-to-date.
740# Use auto.conf to trigger the test
741PHONY += include/config/auto.conf
742
743include/config/auto.conf:
744	$(Q)test -e include/generated/autoconf.h -a -e $@ || (		\
745	echo >&2;							\
746	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
747	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
748	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
749	echo >&2 ;							\
750	/bin/false)
751
752endif # may-sync-config
753endif # need-config
754
755KBUILD_CFLAGS	+= $(call cc-option,-fno-delete-null-pointer-checks,)
756KBUILD_CFLAGS	+= $(call cc-disable-warning,frame-address,)
757KBUILD_CFLAGS	+= $(call cc-disable-warning, format-truncation)
758KBUILD_CFLAGS	+= $(call cc-disable-warning, format-overflow)
759KBUILD_CFLAGS	+= $(call cc-disable-warning, address-of-packed-member)
760
761ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
762KBUILD_CFLAGS += -O2
763else ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3
764KBUILD_CFLAGS += -O3
765else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
766KBUILD_CFLAGS += -Os
767endif
768
769# Tell gcc to never replace conditional load with a non-conditional one
770KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
771KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
772
773ifdef CONFIG_READABLE_ASM
774# Disable optimizations that make assembler listings hard to read.
775# reorder blocks reorders the control in the function
776# ipa clone creates specialized cloned functions
777# partial inlining inlines only parts of functions
778KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
779                 $(call cc-option,-fno-ipa-cp-clone,) \
780                 $(call cc-option,-fno-partial-inlining)
781endif
782
783ifneq ($(CONFIG_FRAME_WARN),0)
784KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
785endif
786
787stackp-flags-y                                    := -fno-stack-protector
788stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
789stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
790
791KBUILD_CFLAGS += $(stackp-flags-y)
792
793ifdef CONFIG_CC_IS_CLANG
794KBUILD_CPPFLAGS += -Qunused-arguments
795KBUILD_CFLAGS += -Wno-format-invalid-specifier
796KBUILD_CFLAGS += -Wno-gnu
797# CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
798# source of a reference will be _MergedGlobals and not on of the whitelisted names.
799# See modpost pattern 2
800KBUILD_CFLAGS += -mno-global-merge
801else
802
803# Warn about unmarked fall-throughs in switch statement.
804# Disabled for clang while comment to attribute conversion happens and
805# https://github.com/ClangBuiltLinux/linux/issues/636 is discussed.
806KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough=5,)
807endif
808
809# These warnings generated too much noise in a regular build.
810# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
811KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
812
813KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
814ifdef CONFIG_FRAME_POINTER
815KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
816else
817# Some targets (ARM with Thumb2, for example), can't be built with frame
818# pointers.  For those, we don't have FUNCTION_TRACER automatically
819# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
820# incompatible with -fomit-frame-pointer with current GCC, so we don't use
821# -fomit-frame-pointer with FUNCTION_TRACER.
822ifndef CONFIG_FUNCTION_TRACER
823KBUILD_CFLAGS	+= -fomit-frame-pointer
824endif
825endif
826
827# Initialize all stack variables with a 0xAA pattern.
828ifdef CONFIG_INIT_STACK_ALL_PATTERN
829KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
830endif
831
832# Initialize all stack variables with a zero value.
833ifdef CONFIG_INIT_STACK_ALL_ZERO
834# Future support for zero initialization is still being debated, see
835# https://bugs.llvm.org/show_bug.cgi?id=45497. These flags are subject to being
836# renamed or dropped.
837KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
838KBUILD_CFLAGS	+= -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
839endif
840
841# While VLAs have been removed, GCC produces unreachable stack probes
842# for the randomize_kstack_offset feature. Disable it for all compilers.
843KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
844
845DEBUG_CFLAGS	:=
846
847# Workaround for GCC versions < 5.0
848# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61801
849ifdef CONFIG_CC_IS_GCC
850DEBUG_CFLAGS	+= $(call cc-ifversion, -lt, 0500, $(call cc-option, -fno-var-tracking-assignments))
851endif
852
853ifdef CONFIG_DEBUG_INFO
854
855ifdef CONFIG_DEBUG_INFO_SPLIT
856DEBUG_CFLAGS	+= -gsplit-dwarf
857else
858DEBUG_CFLAGS	+= -g
859endif
860
861ifneq ($(LLVM_IAS),1)
862KBUILD_AFLAGS	+= -Wa,-gdwarf-2
863endif
864
865ifndef CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
866dwarf-version-$(CONFIG_DEBUG_INFO_DWARF4) := 4
867dwarf-version-$(CONFIG_DEBUG_INFO_DWARF5) := 5
868DEBUG_CFLAGS	+= -gdwarf-$(dwarf-version-y)
869endif
870
871ifdef CONFIG_DEBUG_INFO_REDUCED
872DEBUG_CFLAGS	+= $(call cc-option, -femit-struct-debug-baseonly) \
873		   $(call cc-option,-fno-var-tracking)
874endif
875
876ifdef CONFIG_DEBUG_INFO_COMPRESSED
877DEBUG_CFLAGS	+= -gz=zlib
878KBUILD_AFLAGS	+= -gz=zlib
879KBUILD_LDFLAGS	+= --compress-debug-sections=zlib
880endif
881
882endif # CONFIG_DEBUG_INFO
883
884KBUILD_CFLAGS += $(DEBUG_CFLAGS)
885export DEBUG_CFLAGS
886
887ifdef CONFIG_FUNCTION_TRACER
888ifdef CONFIG_FTRACE_MCOUNT_USE_CC
889  CC_FLAGS_FTRACE	+= -mrecord-mcount
890  ifdef CONFIG_HAVE_NOP_MCOUNT
891    ifeq ($(call cc-option-yn, -mnop-mcount),y)
892      CC_FLAGS_FTRACE	+= -mnop-mcount
893      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
894    endif
895  endif
896endif
897ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
898  CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
899endif
900ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
901  ifdef CONFIG_HAVE_C_RECORDMCOUNT
902    BUILD_C_RECORDMCOUNT := y
903    export BUILD_C_RECORDMCOUNT
904  endif
905endif
906ifdef CONFIG_HAVE_FENTRY
907  ifeq ($(call cc-option-yn, -mfentry),y)
908    CC_FLAGS_FTRACE	+= -mfentry
909    CC_FLAGS_USING	+= -DCC_USING_FENTRY
910  endif
911endif
912export CC_FLAGS_FTRACE
913KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
914KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
915endif
916
917# We trigger additional mismatches with less inlining
918ifdef CONFIG_DEBUG_SECTION_MISMATCH
919KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
920endif
921
922ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
923KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
924LDFLAGS_vmlinux += --gc-sections
925endif
926
927ifdef CONFIG_SHADOW_CALL_STACK
928CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
929KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
930export CC_FLAGS_SCS
931endif
932
933ifdef CONFIG_LTO_CLANG
934ifdef CONFIG_LTO_CLANG_THIN
935CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
936KBUILD_LDFLAGS	+= --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
937else
938CC_FLAGS_LTO	:= -flto
939endif
940CC_FLAGS_LTO	+= -fvisibility=hidden
941
942# Limit inlining across translation units to reduce binary size
943KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
944
945# Check for frame size exceeding threshold during prolog/epilog insertion
946# when using lld < 13.0.0.
947ifneq ($(CONFIG_FRAME_WARN),0)
948ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
949KBUILD_LDFLAGS	+= -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
950endif
951endif
952endif
953
954ifdef CONFIG_LTO
955KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
956KBUILD_AFLAGS	+= -fno-lto
957export CC_FLAGS_LTO
958endif
959
960ifdef CONFIG_CFI_CLANG
961CC_FLAGS_CFI	:= -fsanitize=cfi \
962		   -fsanitize-cfi-cross-dso \
963		   -fno-sanitize-cfi-canonical-jump-tables \
964		   -fno-sanitize-trap=cfi \
965		   -fno-sanitize-blacklist
966
967ifdef CONFIG_CFI_PERMISSIVE
968CC_FLAGS_CFI	+= -fsanitize-recover=cfi
969endif
970
971# If LTO flags are filtered out, we must also filter out CFI.
972CC_FLAGS_LTO	+= $(CC_FLAGS_CFI)
973KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
974export CC_FLAGS_CFI
975endif
976
977ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B
978KBUILD_CFLAGS += -falign-functions=64
979endif
980
981# arch Makefile may override CC so keep this after arch Makefile is included
982NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
983
984# warn about C99 declaration after statement
985KBUILD_CFLAGS += -Wdeclaration-after-statement
986
987# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
988KBUILD_CFLAGS += -Wvla
989
990# disable pointer signed / unsigned warnings in gcc 4.0
991KBUILD_CFLAGS += -Wno-pointer-sign
992
993# disable stringop warnings in gcc 8+
994KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
995
996# We'll want to enable this eventually, but it's not going away for 5.7 at least
997KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds)
998KBUILD_CFLAGS += $(call cc-disable-warning, array-bounds)
999KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
1000
1001# Another good warning that we'll want to enable eventually
1002KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
1003
1004# Enabled with W=2, disabled by default as noisy
1005KBUILD_CFLAGS += $(call cc-disable-warning, maybe-uninitialized)
1006
1007# disable invalid "can't wrap" optimizations for signed / pointers
1008KBUILD_CFLAGS	+= -fno-strict-overflow
1009
1010# Make sure -fstack-check isn't enabled (like gentoo apparently did)
1011KBUILD_CFLAGS  += -fno-stack-check
1012
1013# conserve stack if available
1014KBUILD_CFLAGS   += $(call cc-option,-fconserve-stack)
1015
1016# Prohibit date/time macros, which would make the build non-deterministic
1017KBUILD_CFLAGS   += -Werror=date-time
1018
1019# enforce correct pointer usage
1020KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
1021
1022# Require designated initializers for all marked structures
1023KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
1024
1025# change __FILE__ to the relative path from the srctree
1026KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1027
1028# include additional Makefiles when needed
1029include-y			:= scripts/Makefile.extrawarn
1030include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1031include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1032include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1033include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1034include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1035
1036include $(addprefix $(srctree)/, $(include-y))
1037
1038# scripts/Makefile.gcc-plugins is intentionally included last.
1039# Do not add $(call cc-option,...) below this line. When you build the kernel
1040# from the clean source tree, the GCC plugins do not exist at this point.
1041
1042# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
1043KBUILD_CPPFLAGS += $(KCPPFLAGS)
1044KBUILD_AFLAGS   += $(KAFLAGS)
1045KBUILD_CFLAGS   += $(KCFLAGS)
1046
1047KBUILD_LDFLAGS_MODULE += --build-id=sha1
1048LDFLAGS_vmlinux += --build-id=sha1
1049
1050ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1051LDFLAGS_vmlinux	+= $(call ld-option, -X,)
1052endif
1053
1054ifeq ($(CONFIG_RELR),y)
1055LDFLAGS_vmlinux	+= --pack-dyn-relocs=relr --use-android-relr-tags
1056endif
1057
1058# We never want expected sections to be placed heuristically by the
1059# linker. All sections should be explicitly named in the linker script.
1060ifdef CONFIG_LD_ORPHAN_WARN
1061LDFLAGS_vmlinux += --orphan-handling=warn
1062endif
1063
1064# Align the bit size of userspace programs with the kernel
1065KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1066KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1067
1068# make the checker run with the right architecture
1069CHECKFLAGS += --arch=$(ARCH)
1070
1071# insure the checker run with the right endianness
1072CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1073
1074# the checker needs the correct machine size
1075CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1076
1077# Default kernel image to build when no specific target is given.
1078# KBUILD_IMAGE may be overruled on the command line or
1079# set in the environment
1080# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1081# this default value
1082export KBUILD_IMAGE ?= vmlinux
1083
1084#
1085# INSTALL_PATH specifies where to place the updated kernel and system map
1086# images. Default is /boot, but you can set it to other values
1087export	INSTALL_PATH ?= /boot
1088
1089#
1090# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1091# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1092# an argument if needed. Otherwise it defaults to the kernel install path
1093#
1094export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1095
1096#
1097# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1098# relocations required by build roots.  This is not defined in the
1099# makefile but the argument can be passed to make if needed.
1100#
1101
1102MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1103export MODLIB
1104
1105PHONY += prepare0
1106
1107export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1108export MODORDER := $(extmod_prefix)modules.order
1109export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1110
1111ifeq ($(KBUILD_EXTMOD),)
1112core-y		+= kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
1113
1114vmlinux-dirs	:= $(patsubst %/,%,$(filter %/, \
1115		     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1116		     $(libs-y) $(libs-m)))
1117
1118vmlinux-alldirs	:= $(sort $(vmlinux-dirs) Documentation \
1119		     $(patsubst %/,%,$(filter %/, $(core-) \
1120			$(drivers-) $(libs-))))
1121
1122subdir-modorder := $(addsuffix modules.order,$(filter %/, \
1123			$(core-y) $(core-m) $(libs-y) $(libs-m) \
1124			$(drivers-y) $(drivers-m)))
1125
1126build-dirs	:= $(vmlinux-dirs)
1127clean-dirs	:= $(vmlinux-alldirs)
1128
1129# Externally visible symbols (used by link-vmlinux.sh)
1130KBUILD_VMLINUX_OBJS := $(head-y) $(patsubst %/,%/built-in.a, $(core-y))
1131KBUILD_VMLINUX_OBJS += $(addsuffix built-in.a, $(filter %/, $(libs-y)))
1132ifdef CONFIG_MODULES
1133KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1134KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1135else
1136KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1137endif
1138KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y))
1139
1140export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
1141export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1142# used by scripts/Makefile.package
1143export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1144
1145vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1146
1147# Recurse until adjust_autoksyms.sh is satisfied
1148PHONY += autoksyms_recursive
1149ifdef CONFIG_TRIM_UNUSED_KSYMS
1150# For the kernel to actually contain only the needed exported symbols,
1151# we have to build modules as well to determine what those symbols are.
1152# (this can be evaluated only once include/config/auto.conf has been included)
1153KBUILD_MODULES := 1
1154
1155autoksyms_recursive: descend modules.order
1156	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1157	  "$(MAKE) -f $(srctree)/Makefile vmlinux"
1158endif
1159
1160autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1161
1162quiet_cmd_autoksyms_h = GEN     $@
1163      cmd_autoksyms_h = mkdir -p $(dir $@); \
1164			$(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1165
1166$(autoksyms_h):
1167	$(call cmd,autoksyms_h)
1168
1169ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1170
1171# Final link of vmlinux with optional arch pass after final link
1172cmd_link-vmlinux =                                                 \
1173	$(CONFIG_SHELL) $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)";    \
1174	$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1175
1176vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1177	+$(call if_changed_dep,link-vmlinux)
1178
1179targets := vmlinux
1180
1181# The actual objects are generated when descending,
1182# make sure no implicit rule kicks in
1183$(sort $(vmlinux-deps) $(subdir-modorder)): descend ;
1184
1185filechk_kernel.release = \
1186	echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1187
1188# Store (new) KERNELRELEASE string in include/config/kernel.release
1189include/config/kernel.release: FORCE
1190	$(call filechk,kernel.release)
1191
1192# Additional helpers built in scripts/
1193# Carefully list dependencies so we do not try to build scripts twice
1194# in parallel
1195PHONY += scripts
1196scripts: scripts_basic scripts_dtc
1197	$(Q)$(MAKE) $(build)=$(@)
1198
1199# Things we need to do before we recursively start building the kernel
1200# or the modules are listed in "prepare".
1201# A multi level approach is used. prepareN is processed before prepareN-1.
1202# archprepare is used in arch Makefiles and when processed asm symlink,
1203# version.h and scripts_basic is processed / created.
1204
1205PHONY += prepare archprepare
1206
1207archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1208	asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1209	include/generated/autoconf.h remove-stale-files
1210
1211prepare0: archprepare
1212	$(Q)$(MAKE) $(build)=scripts/mod
1213	$(Q)$(MAKE) $(build)=.
1214
1215# All the preparing..
1216prepare: prepare0
1217
1218PHONY += remove-stale-files
1219remove-stale-files:
1220	$(Q)$(srctree)/scripts/remove-stale-files
1221
1222# Support for using generic headers in asm-generic
1223asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1224
1225PHONY += asm-generic uapi-asm-generic
1226asm-generic: uapi-asm-generic
1227	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1228	generic=include/asm-generic
1229uapi-asm-generic:
1230	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1231	generic=include/uapi/asm-generic
1232
1233# Generate some files
1234# ---------------------------------------------------------------------------
1235
1236# KERNELRELEASE can change from a few different places, meaning version.h
1237# needs to be updated, so this check is forced on all builds
1238
1239uts_len := 64
1240define filechk_utsrelease.h
1241	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1242	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1243	  exit 1;                                                         \
1244	fi;                                                               \
1245	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1246endef
1247
1248define filechk_version.h
1249	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1250		echo \#define LINUX_VERSION_CODE $(shell                 \
1251		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1252	else                                                             \
1253		echo \#define LINUX_VERSION_CODE $(shell                 \
1254		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1255	fi;                                                              \
1256	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1257	((c) > 255 ? 255 : (c)))';                                       \
1258	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1259	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1260	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1261endef
1262
1263$(version_h): PATCHLEVEL := $(if $(PATCHLEVEL), $(PATCHLEVEL), 0)
1264$(version_h): SUBLEVEL := $(if $(SUBLEVEL), $(SUBLEVEL), 0)
1265$(version_h): FORCE
1266	$(call filechk,version.h)
1267
1268include/generated/utsrelease.h: include/config/kernel.release FORCE
1269	$(call filechk,utsrelease.h)
1270
1271PHONY += headerdep
1272headerdep:
1273	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1274	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1275
1276# ---------------------------------------------------------------------------
1277# Kernel headers
1278
1279#Default location for installed headers
1280export INSTALL_HDR_PATH = $(objtree)/usr
1281
1282quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1283      cmd_headers_install = \
1284	mkdir -p $(INSTALL_HDR_PATH); \
1285	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1286	usr/include $(INSTALL_HDR_PATH)
1287
1288PHONY += headers_install
1289headers_install: headers
1290	$(call cmd,headers_install)
1291
1292PHONY += archheaders archscripts
1293
1294hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1295
1296PHONY += headers
1297headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1298	$(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1299	  $(error Headers not exportable for the $(SRCARCH) architecture))
1300	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1301	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1302
1303# Deprecated. It is no-op now.
1304PHONY += headers_check
1305headers_check:
1306	@echo >&2 "=================== WARNING ==================="
1307	@echo >&2 "Since Linux 5.5, 'make headers_check' is no-op,"
1308	@echo >&2 "and will be removed after Linux 5.15 release."
1309	@echo >&2 "Please remove headers_check from your scripts."
1310	@echo >&2 "==============================================="
1311
1312ifdef CONFIG_HEADERS_INSTALL
1313prepare: headers
1314endif
1315
1316PHONY += scripts_unifdef
1317scripts_unifdef: scripts_basic
1318	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1319
1320# ---------------------------------------------------------------------------
1321# Tools
1322
1323ifdef CONFIG_STACK_VALIDATION
1324prepare: tools/objtool
1325endif
1326
1327ifdef CONFIG_BPF
1328ifdef CONFIG_DEBUG_INFO_BTF
1329prepare: tools/bpf/resolve_btfids
1330endif
1331endif
1332
1333PHONY += resolve_btfids_clean
1334
1335resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1336
1337# tools/bpf/resolve_btfids directory might not exist
1338# in output directory, skip its clean in that case
1339resolve_btfids_clean:
1340ifneq ($(wildcard $(resolve_btfids_O)),)
1341	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1342endif
1343
1344# Clear a bunch of variables before executing the submake
1345ifeq ($(quiet),silent_)
1346tools_silent=s
1347endif
1348
1349tools/: FORCE
1350	$(Q)mkdir -p $(objtree)/tools
1351	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1352
1353tools/%: FORCE
1354	$(Q)mkdir -p $(objtree)/tools
1355	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1356
1357# ---------------------------------------------------------------------------
1358# Kernel selftest
1359
1360PHONY += kselftest
1361kselftest:
1362	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1363
1364kselftest-%: FORCE
1365	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1366
1367PHONY += kselftest-merge
1368kselftest-merge:
1369	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1370	$(Q)find $(srctree)/tools/testing/selftests -name config | \
1371		xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1372	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1373
1374# ---------------------------------------------------------------------------
1375# Devicetree files
1376
1377ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1378dtstree := arch/$(SRCARCH)/boot/dts
1379endif
1380
1381ifneq ($(dtstree),)
1382
1383%.dtb: include/config/kernel.release scripts_dtc
1384	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1385
1386%.dtbo: include/config/kernel.release scripts_dtc
1387	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1388
1389PHONY += dtbs dtbs_install dtbs_check
1390dtbs: include/config/kernel.release scripts_dtc
1391	$(Q)$(MAKE) $(build)=$(dtstree)
1392
1393ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1394export CHECK_DTBS=y
1395dtbs: dt_binding_check
1396endif
1397
1398dtbs_check: dtbs
1399
1400dtbs_install:
1401	$(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1402
1403ifdef CONFIG_OF_EARLY_FLATTREE
1404all: dtbs
1405endif
1406
1407endif
1408
1409PHONY += scripts_dtc
1410scripts_dtc: scripts_basic
1411	$(Q)$(MAKE) $(build)=scripts/dtc
1412
1413ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1414export CHECK_DT_BINDING=y
1415endif
1416
1417PHONY += dt_binding_check
1418dt_binding_check: scripts_dtc
1419	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1420
1421# ---------------------------------------------------------------------------
1422# Modules
1423
1424ifdef CONFIG_MODULES
1425
1426# By default, build modules as well
1427
1428all: modules
1429
1430# When we're building modules with modversions, we need to consider
1431# the built-in objects during the descend as well, in order to
1432# make sure the checksums are up to date before we record them.
1433ifdef CONFIG_MODVERSIONS
1434  KBUILD_BUILTIN := 1
1435endif
1436
1437# Build modules
1438#
1439# A module can be listed more than once in obj-m resulting in
1440# duplicate lines in modules.order files.  Those are removed
1441# using awk while concatenating to the final file.
1442
1443PHONY += modules
1444modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
1445
1446cmd_modules_order = $(AWK) '!x[$$0]++' $(real-prereqs) > $@
1447
1448modules.order: $(subdir-modorder) FORCE
1449	$(call if_changed,modules_order)
1450
1451targets += modules.order
1452
1453# Target to prepare building external modules
1454PHONY += modules_prepare
1455modules_prepare: prepare
1456	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1457
1458export modules_sign_only :=
1459
1460ifeq ($(CONFIG_MODULE_SIG),y)
1461PHONY += modules_sign
1462modules_sign: modules_install
1463	@:
1464
1465# modules_sign is a subset of modules_install.
1466# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1467ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
1468modules_sign_only := y
1469endif
1470endif
1471
1472modinst_pre :=
1473ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
1474modinst_pre := __modinst_pre
1475endif
1476
1477modules_install: $(modinst_pre)
1478PHONY += __modinst_pre
1479__modinst_pre:
1480	@rm -rf $(MODLIB)/kernel
1481	@rm -f $(MODLIB)/source
1482	@mkdir -p $(MODLIB)/kernel
1483	@ln -s $(abspath $(srctree)) $(MODLIB)/source
1484	@if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1485		rm -f $(MODLIB)/build ; \
1486		ln -s $(CURDIR) $(MODLIB)/build ; \
1487	fi
1488	@sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1489	@cp -f modules.builtin $(MODLIB)/
1490	@cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1491
1492endif # CONFIG_MODULES
1493
1494###
1495# Cleaning is done on three levels.
1496# make clean     Delete most generated files
1497#                Leave enough to build external modules
1498# make mrproper  Delete the current configuration, and all generated files
1499# make distclean Remove editor backup files, patch leftover files and the like
1500
1501# Directories & files removed with 'make clean'
1502CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1503	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1504	       compile_commands.json .thinlto-cache
1505
1506# Directories & files removed with 'make mrproper'
1507MRPROPER_FILES += include/config include/generated          \
1508		  arch/$(SRCARCH)/include/generated .tmp_objdiff \
1509		  debian snap tar-install \
1510		  .config .config.old .version \
1511		  Module.symvers \
1512		  certs/signing_key.pem certs/signing_key.x509 \
1513		  certs/x509.genkey \
1514		  vmlinux-gdb.py \
1515		  *.spec
1516
1517# clean - Delete most, but leave enough to build external modules
1518#
1519clean: rm-files := $(CLEAN_FILES)
1520
1521PHONY += archclean vmlinuxclean
1522
1523vmlinuxclean:
1524	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1525	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1526
1527clean: archclean vmlinuxclean resolve_btfids_clean
1528
1529# mrproper - Delete all generated files, including .config
1530#
1531mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1532mrproper-dirs      := $(addprefix _mrproper_,scripts)
1533
1534PHONY += $(mrproper-dirs) mrproper
1535$(mrproper-dirs):
1536	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1537
1538mrproper: clean $(mrproper-dirs)
1539	$(call cmd,rmfiles)
1540
1541# distclean
1542#
1543PHONY += distclean
1544
1545distclean: mrproper
1546	@find . $(RCS_FIND_IGNORE) \
1547		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1548		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1549		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1550		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1551		-type f -print | xargs rm -f
1552
1553
1554# Packaging of the kernel to various formats
1555# ---------------------------------------------------------------------------
1556
1557%src-pkg: FORCE
1558	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1559%pkg: include/config/kernel.release FORCE
1560	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1561
1562# Brief documentation of the typical targets used
1563# ---------------------------------------------------------------------------
1564
1565boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1566boards := $(sort $(notdir $(boards)))
1567board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1568board-dirs := $(sort $(notdir $(board-dirs:/=)))
1569
1570PHONY += help
1571help:
1572	@echo  'Cleaning targets:'
1573	@echo  '  clean		  - Remove most generated files but keep the config and'
1574	@echo  '                    enough build support to build external modules'
1575	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1576	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1577	@echo  ''
1578	@echo  'Configuration targets:'
1579	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1580	@echo  ''
1581	@echo  'Other generic targets:'
1582	@echo  '  all		  - Build all targets marked with [*]'
1583	@echo  '* vmlinux	  - Build the bare kernel'
1584	@echo  '* modules	  - Build all modules'
1585	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1586	@echo  '  dir/            - Build all files in dir and below'
1587	@echo  '  dir/file.[ois]  - Build specified target only'
1588	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1589	@echo  '                    (requires compiler support for LLVM assembly generation)'
1590	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1591	@echo  '                    (requires a recent binutils and recent build (System.map))'
1592	@echo  '  dir/file.ko     - Build module including final link'
1593	@echo  '  modules_prepare - Set up for building external modules'
1594	@echo  '  tags/TAGS	  - Generate tags file for editors'
1595	@echo  '  cscope	  - Generate cscope index'
1596	@echo  '  gtags           - Generate GNU GLOBAL index'
1597	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1598	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1599	@echo  '  image_name	  - Output the image name (use with make -s)'
1600	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1601	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1602	 echo  ''
1603	@echo  'Static analysers:'
1604	@echo  '  checkstack      - Generate a list of stack hogs'
1605	@echo  '  versioncheck    - Sanity check on version.h usage'
1606	@echo  '  includecheck    - Check for duplicate included header files'
1607	@echo  '  export_report   - List the usages of all exported symbols'
1608	@echo  '  headerdep       - Detect inclusion cycles in headers'
1609	@echo  '  coccicheck      - Check with Coccinelle'
1610	@echo  '  clang-analyzer  - Check with clang static analyzer'
1611	@echo  '  clang-tidy      - Check with clang-tidy'
1612	@echo  ''
1613	@echo  'Tools:'
1614	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1615	@echo  ''
1616	@echo  'Kernel selftest:'
1617	@echo  '  kselftest         - Build and run kernel selftest'
1618	@echo  '                      Build, install, and boot kernel before'
1619	@echo  '                      running kselftest on it'
1620	@echo  '                      Run as root for full coverage'
1621	@echo  '  kselftest-all     - Build kernel selftest'
1622	@echo  '  kselftest-install - Build and install kernel selftest'
1623	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1624	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1625	@echo  '		      kselftest to existing .config.'
1626	@echo  ''
1627	@$(if $(dtstree), \
1628		echo 'Devicetree:'; \
1629		echo '* dtbs             - Build device tree blobs for enabled boards'; \
1630		echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1631		echo '  dt_binding_check - Validate device tree binding documents'; \
1632		echo '  dtbs_check       - Validate device tree source files';\
1633		echo '')
1634
1635	@echo 'Userspace tools targets:'
1636	@echo '  use "make tools/help"'
1637	@echo '  or  "cd tools; make help"'
1638	@echo  ''
1639	@echo  'Kernel packaging:'
1640	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1641	@echo  ''
1642	@echo  'Documentation targets:'
1643	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1644	@echo  ''
1645	@echo  'Architecture specific targets ($(SRCARCH)):'
1646	@$(if $(archhelp),$(archhelp),\
1647		echo '  No architecture specific help defined for $(SRCARCH)')
1648	@echo  ''
1649	@$(if $(boards), \
1650		$(foreach b, $(boards), \
1651		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1652		echo '')
1653	@$(if $(board-dirs), \
1654		$(foreach b, $(board-dirs), \
1655		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1656		printf "  %-16s - Show all of the above\\n" help-boards; \
1657		echo '')
1658
1659	@echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1660	@echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1661	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1662	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1663	@echo  '                       (sparse by default)'
1664	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1665	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1666	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1667	@echo  '		1: warnings which may be relevant and do not occur too often'
1668	@echo  '		2: warnings which occur quite often but may still be relevant'
1669	@echo  '		3: more obscure warnings, can most likely be ignored'
1670	@echo  '		Multiple levels can be combined with W=12 or W=123'
1671	@echo  ''
1672	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1673	@echo  'For further info see the ./README file'
1674
1675
1676help-board-dirs := $(addprefix help-,$(board-dirs))
1677
1678help-boards: $(help-board-dirs)
1679
1680boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1681
1682$(help-board-dirs): help-%:
1683	@echo  'Architecture specific targets ($(SRCARCH) $*):'
1684	@$(if $(boards-per-dir), \
1685		$(foreach b, $(boards-per-dir), \
1686		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1687		echo '')
1688
1689
1690# Documentation targets
1691# ---------------------------------------------------------------------------
1692DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1693	       linkcheckdocs dochelp refcheckdocs
1694PHONY += $(DOC_TARGETS)
1695$(DOC_TARGETS):
1696	$(Q)$(MAKE) $(build)=Documentation $@
1697
1698# Misc
1699# ---------------------------------------------------------------------------
1700
1701PHONY += scripts_gdb
1702scripts_gdb: prepare0
1703	$(Q)$(MAKE) $(build)=scripts/gdb
1704	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1705
1706ifdef CONFIG_GDB_SCRIPTS
1707all: scripts_gdb
1708endif
1709
1710else # KBUILD_EXTMOD
1711
1712###
1713# External module support.
1714# When building external modules the kernel used as basis is considered
1715# read-only, and no consistency checks are made and the make
1716# system is not used on the basis kernel. If updates are required
1717# in the basis kernel ordinary make commands (without M=...) must be used.
1718
1719# We are always building only modules.
1720KBUILD_BUILTIN :=
1721KBUILD_MODULES := 1
1722
1723build-dirs := $(KBUILD_EXTMOD)
1724$(MODORDER): descend
1725	@:
1726
1727compile_commands.json: $(extmod_prefix)compile_commands.json
1728PHONY += compile_commands.json
1729
1730clean-dirs := $(KBUILD_EXTMOD)
1731clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1732	$(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1733
1734PHONY += help
1735help:
1736	@echo  '  Building external modules.'
1737	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1738	@echo  ''
1739	@echo  '  modules         - default target, build the module(s)'
1740	@echo  '  modules_install - install the module'
1741	@echo  '  clean           - remove generated files in module directory only'
1742	@echo  ''
1743
1744# no-op for external module builds
1745PHONY += prepare modules_prepare
1746
1747endif # KBUILD_EXTMOD
1748
1749# ---------------------------------------------------------------------------
1750# Modules
1751
1752PHONY += modules modules_install
1753
1754ifdef CONFIG_MODULES
1755
1756modules: modules_check
1757	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1758
1759PHONY += modules_check
1760modules_check: $(MODORDER)
1761	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1762
1763quiet_cmd_depmod = DEPMOD  $(MODLIB)
1764      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1765                   $(KERNELRELEASE)
1766
1767modules_install:
1768	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1769	$(call cmd,depmod)
1770
1771else # CONFIG_MODULES
1772
1773# Modules not configured
1774# ---------------------------------------------------------------------------
1775
1776modules modules_install:
1777	@echo >&2 '***'
1778	@echo >&2 '*** The present kernel configuration has modules disabled.'
1779	@echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
1780	@echo >&2 '*** to enable CONFIG_MODULES.'
1781	@echo >&2 '***'
1782	@exit 1
1783
1784endif # CONFIG_MODULES
1785
1786# Single targets
1787# ---------------------------------------------------------------------------
1788# To build individual files in subdirectories, you can do like this:
1789#
1790#   make foo/bar/baz.s
1791#
1792# The supported suffixes for single-target are listed in 'single-targets'
1793#
1794# To build only under specific subdirectories, you can do like this:
1795#
1796#   make foo/bar/baz/
1797
1798ifdef single-build
1799
1800# .ko is special because modpost is needed
1801single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1802single-no-ko := $(sort $(patsubst %.ko,%.mod, $(MAKECMDGOALS)))
1803
1804$(single-ko): single_modpost
1805	@:
1806$(single-no-ko): descend
1807	@:
1808
1809ifeq ($(KBUILD_EXTMOD),)
1810# For the single build of in-tree modules, use a temporary file to avoid
1811# the situation of modules_install installing an invalid modules.order.
1812MODORDER := .modules.tmp
1813endif
1814
1815PHONY += single_modpost
1816single_modpost: $(single-no-ko) modules_prepare
1817	$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER)
1818	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1819
1820KBUILD_MODULES := 1
1821
1822export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod_prefix), $(single-no-ko))
1823
1824# trim unrelated directories
1825build-dirs := $(foreach d, $(build-dirs), \
1826			$(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
1827
1828endif
1829
1830ifndef CONFIG_MODULES
1831KBUILD_MODULES :=
1832endif
1833
1834# Handle descending into subdirectories listed in $(build-dirs)
1835# Preset locale variables to speed up the build process. Limit locale
1836# tweaks to this spot to avoid wrong language settings when running
1837# make menuconfig etc.
1838# Error messages still appears in the original language
1839PHONY += descend $(build-dirs)
1840descend: $(build-dirs)
1841$(build-dirs): prepare
1842	$(Q)$(MAKE) $(build)=$@ \
1843	single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
1844	need-builtin=1 need-modorder=1
1845
1846clean-dirs := $(addprefix _clean_, $(clean-dirs))
1847PHONY += $(clean-dirs) clean
1848$(clean-dirs):
1849	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1850
1851clean: $(clean-dirs)
1852	$(call cmd,rmfiles)
1853	@find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1854		\( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1855		-o -name '*.ko.*' \
1856		-o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1857		-o -name '*.dwo' -o -name '*.lst' \
1858		-o -name '*.su' -o -name '*.mod' \
1859		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1860		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
1861		-o -name '*.asn1.[ch]' \
1862		-o -name '*.symtypes' -o -name 'modules.order' \
1863		-o -name '.tmp_*.o.*' \
1864		-o -name '*.c.[012]*.*' \
1865		-o -name '*.ll' \
1866		-o -name '*.gcno' \
1867		-o -name '*.*.symversions' \) -type f -print | xargs rm -f
1868
1869# Generate tags for editors
1870# ---------------------------------------------------------------------------
1871quiet_cmd_tags = GEN     $@
1872      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1873
1874tags TAGS cscope gtags: FORCE
1875	$(call cmd,tags)
1876
1877# Script to generate missing namespace dependencies
1878# ---------------------------------------------------------------------------
1879
1880PHONY += nsdeps
1881nsdeps: export KBUILD_NSDEPS=1
1882nsdeps: modules
1883	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1884
1885# Clang Tooling
1886# ---------------------------------------------------------------------------
1887
1888quiet_cmd_gen_compile_commands = GEN     $@
1889      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1890
1891$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1892	$(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
1893	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1894	$(call if_changed,gen_compile_commands)
1895
1896targets += $(extmod_prefix)compile_commands.json
1897
1898PHONY += clang-tidy clang-analyzer
1899
1900ifdef CONFIG_CC_IS_CLANG
1901quiet_cmd_clang_tools = CHECK   $<
1902      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1903
1904clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
1905	$(call cmd,clang_tools)
1906else
1907clang-tidy clang-analyzer:
1908	@echo "$@ requires CC=clang" >&2
1909	@false
1910endif
1911
1912# Scripts to check various things for consistency
1913# ---------------------------------------------------------------------------
1914
1915PHONY += includecheck versioncheck coccicheck export_report
1916
1917includecheck:
1918	find $(srctree)/* $(RCS_FIND_IGNORE) \
1919		-name '*.[hcS]' -type f -print | sort \
1920		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1921
1922versioncheck:
1923	find $(srctree)/* $(RCS_FIND_IGNORE) \
1924		-name '*.[hcS]' -type f -print | sort \
1925		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1926
1927coccicheck:
1928	$(Q)$(BASH) $(srctree)/scripts/$@
1929
1930export_report:
1931	$(PERL) $(srctree)/scripts/export_report.pl
1932
1933PHONY += checkstack kernelrelease kernelversion image_name
1934
1935# UML needs a little special treatment here.  It wants to use the host
1936# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
1937# else wants $(ARCH), including people doing cross-builds, which means
1938# that $(SUBARCH) doesn't work here.
1939ifeq ($(ARCH), um)
1940CHECKSTACK_ARCH := $(SUBARCH)
1941else
1942CHECKSTACK_ARCH := $(ARCH)
1943endif
1944checkstack:
1945	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1946	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1947
1948kernelrelease:
1949	@echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1950
1951kernelversion:
1952	@echo $(KERNELVERSION)
1953
1954image_name:
1955	@echo $(KBUILD_IMAGE)
1956
1957quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
1958      cmd_rmfiles = rm -rf $(rm-files)
1959
1960# read saved command lines for existing targets
1961existing-targets := $(wildcard $(sort $(targets)))
1962
1963-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1964
1965endif # config-build
1966endif # mixed-build
1967endif # need-sub-make
1968
1969PHONY += FORCE
1970FORCE:
1971
1972# Declare the contents of the PHONY variable as phony.  We keep that
1973# information in a variable so we can use it in if_changed and friends.
1974.PHONY: $(PHONY)
1975