xref: /linux/Makefile (revision f879306834818ebd1722a4372079610cdd466fec)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 6
3PATCHLEVEL = 11
4SUBLEVEL = 0
5EXTRAVERSION = -rc1
6NAME = Baby Opossum Posse
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
14ifeq ($(filter output-sync,$(.FEATURES)),)
15$(error GNU Make >= 4.0 is required. Your Make version is $(MAKE_VERSION))
16endif
17
18$(if $(filter __%, $(MAKECMDGOALS)), \
19	$(error targets prefixed with '__' are only for internal use))
20
21# That's our default target when none is given on the command line
22PHONY := __all
23__all:
24
25# We are using a recursive build, so we need to do a little thinking
26# to get the ordering right.
27#
28# Most importantly: sub-Makefiles should only ever modify files in
29# their own directory. If in some directory we have a dependency on
30# a file in another dir (which doesn't happen often, but it's often
31# unavoidable when linking the built-in.a targets which finally
32# turn into vmlinux), we will call a sub make in that other dir, and
33# after that we are sure that everything which is in that other dir
34# is now up to date.
35#
36# The only cases where we need to modify files which have global
37# effects are thus separated out and done before the recursive
38# descending is started. They are now explicitly listed as the
39# prepare rule.
40
41this-makefile := $(lastword $(MAKEFILE_LIST))
42abs_srctree := $(realpath $(dir $(this-makefile)))
43abs_objtree := $(CURDIR)
44
45ifneq ($(sub_make_done),1)
46
47# Do not use make's built-in rules and variables
48# (this increases performance and avoids hard-to-debug behaviour)
49MAKEFLAGS += -rR
50
51# Avoid funny character set dependencies
52unexport LC_ALL
53LC_COLLATE=C
54LC_NUMERIC=C
55export LC_COLLATE LC_NUMERIC
56
57# Avoid interference with shell env settings
58unexport GREP_OPTIONS
59
60# Beautify output
61# ---------------------------------------------------------------------------
62#
63# Most of build commands in Kbuild start with "cmd_". You can optionally define
64# "quiet_cmd_*". If defined, the short log is printed. Otherwise, no log from
65# that command is printed by default.
66#
67# e.g.)
68#    quiet_cmd_depmod = DEPMOD  $(MODLIB)
69#          cmd_depmod = $(srctree)/scripts/depmod.sh $(DEPMOD) $(KERNELRELEASE)
70#
71# A simple variant is to prefix commands with $(Q) - that's useful
72# for commands that shall be hidden in non-verbose mode.
73#
74#    $(Q)$(MAKE) $(build)=scripts/basic
75#
76# If KBUILD_VERBOSE contains 1, the whole command is echoed.
77# If KBUILD_VERBOSE contains 2, the reason for rebuilding is printed.
78#
79# To put more focus on warnings, be less verbose as default
80# Use 'make V=1' to see the full commands
81
82ifeq ("$(origin V)", "command line")
83  KBUILD_VERBOSE = $(V)
84endif
85
86quiet = quiet_
87Q = @
88
89ifneq ($(findstring 1, $(KBUILD_VERBOSE)),)
90  quiet =
91  Q =
92endif
93
94# If the user is running make -s (silent mode), suppress echoing of
95# commands
96ifneq ($(findstring s,$(firstword -$(MAKEFLAGS))),)
97quiet=silent_
98override KBUILD_VERBOSE :=
99endif
100
101export quiet Q KBUILD_VERBOSE
102
103# Call a source code checker (by default, "sparse") as part of the
104# C compilation.
105#
106# Use 'make C=1' to enable checking of only re-compiled files.
107# Use 'make C=2' to enable checking of *all* source files, regardless
108# of whether they are re-compiled or not.
109#
110# See the file "Documentation/dev-tools/sparse.rst" for more details,
111# including where to get the "sparse" utility.
112
113ifeq ("$(origin C)", "command line")
114  KBUILD_CHECKSRC = $(C)
115endif
116ifndef KBUILD_CHECKSRC
117  KBUILD_CHECKSRC = 0
118endif
119
120export KBUILD_CHECKSRC
121
122# Enable "clippy" (a linter) as part of the Rust compilation.
123#
124# Use 'make CLIPPY=1' to enable it.
125ifeq ("$(origin CLIPPY)", "command line")
126  KBUILD_CLIPPY := $(CLIPPY)
127endif
128
129export KBUILD_CLIPPY
130
131# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
132# directory of external module to build. Setting M= takes precedence.
133ifeq ("$(origin M)", "command line")
134  KBUILD_EXTMOD := $(M)
135endif
136
137$(if $(word 2, $(KBUILD_EXTMOD)), \
138	$(error building multiple external modules is not supported))
139
140$(foreach x, % :, $(if $(findstring $x, $(KBUILD_EXTMOD)), \
141	$(error module directory path cannot contain '$x')))
142
143# Remove trailing slashes
144ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
145KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
146endif
147
148export KBUILD_EXTMOD
149
150# backward compatibility
151KBUILD_EXTRA_WARN ?= $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)
152
153ifeq ("$(origin W)", "command line")
154  KBUILD_EXTRA_WARN := $(W)
155endif
156
157export KBUILD_EXTRA_WARN
158
159# Kbuild will save output files in the current working directory.
160# This does not need to match to the root of the kernel source tree.
161#
162# For example, you can do this:
163#
164#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
165#
166# If you want to save output files in a different location, there are
167# two syntaxes to specify it.
168#
169# 1) O=
170# Use "make O=dir/to/store/output/files/"
171#
172# 2) Set KBUILD_OUTPUT
173# Set the environment variable KBUILD_OUTPUT to point to the output directory.
174# export KBUILD_OUTPUT=dir/to/store/output/files/; make
175#
176# The O= assignment takes precedence over the KBUILD_OUTPUT environment
177# variable.
178
179# Do we want to change the working directory?
180ifeq ("$(origin O)", "command line")
181  KBUILD_OUTPUT := $(O)
182endif
183
184ifneq ($(KBUILD_OUTPUT),)
185# $(realpath ...) gets empty if the path does not exist. Run 'mkdir -p' first.
186$(shell mkdir -p "$(KBUILD_OUTPUT)")
187# $(realpath ...) resolves symlinks
188abs_objtree := $(realpath $(KBUILD_OUTPUT))
189$(if $(abs_objtree),,$(error failed to create output directory "$(KBUILD_OUTPUT)"))
190endif # ifneq ($(KBUILD_OUTPUT),)
191
192ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
193$(error source directory cannot contain spaces or colons)
194endif
195
196export sub_make_done := 1
197
198endif # sub_make_done
199
200ifeq ($(abs_objtree),$(CURDIR))
201# Suppress "Entering directory ..." if we are at the final work directory.
202no-print-directory := --no-print-directory
203else
204# Recursion to show "Entering directory ..."
205need-sub-make := 1
206endif
207
208ifeq ($(filter --no-print-directory, $(MAKEFLAGS)),)
209# If --no-print-directory is unset, recurse once again to set it.
210# You may end up recursing into __sub-make twice. This is needed due to the
211# behavior change in GNU Make 4.4.1.
212need-sub-make := 1
213endif
214
215ifeq ($(need-sub-make),1)
216
217PHONY += $(MAKECMDGOALS) __sub-make
218
219$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
220	@:
221
222# Invoke a second make in the output directory, passing relevant variables
223__sub-make:
224	$(Q)$(MAKE) $(no-print-directory) -C $(abs_objtree) \
225	-f $(abs_srctree)/Makefile $(MAKECMDGOALS)
226
227else # need-sub-make
228
229# We process the rest of the Makefile if this is the final invocation of make
230
231ifeq ($(abs_srctree),$(abs_objtree))
232        # building in the source tree
233        srctree := .
234	building_out_of_srctree :=
235else
236        ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
237                # building in a subdirectory of the source tree
238                srctree := ..
239        else
240                srctree := $(abs_srctree)
241        endif
242	building_out_of_srctree := 1
243endif
244
245ifneq ($(KBUILD_ABS_SRCTREE),)
246srctree := $(abs_srctree)
247endif
248
249objtree		:= .
250
251VPATH		:=
252
253ifeq ($(KBUILD_EXTMOD),)
254ifdef building_out_of_srctree
255VPATH		:= $(srctree)
256endif
257endif
258
259export building_out_of_srctree srctree objtree VPATH
260
261# To make sure we do not include .config for any of the *config targets
262# catch them early, and hand them over to scripts/kconfig/Makefile
263# It is allowed to specify more targets when calling make, including
264# mixing *config targets and build targets.
265# For example 'make oldconfig all'.
266# Detect when mixed targets is specified, and make a second invocation
267# of make so .config is not included in this case either (for *config).
268
269version_h := include/generated/uapi/linux/version.h
270
271clean-targets := %clean mrproper cleandocs
272no-dot-config-targets := $(clean-targets) \
273			 cscope gtags TAGS tags help% %docs check% coccicheck \
274			 $(version_h) headers headers_% archheaders archscripts \
275			 %asm-generic kernelversion %src-pkg dt_binding_check \
276			 outputmakefile rustavailable rustfmt rustfmtcheck
277no-sync-config-targets := $(no-dot-config-targets) %install modules_sign kernelrelease \
278			  image_name
279single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %.symtypes %/
280
281config-build	:=
282mixed-build	:=
283need-config	:= 1
284may-sync-config	:= 1
285single-build	:=
286
287ifneq ($(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-sync-config-targets), $(MAKECMDGOALS)),)
294    ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
295        may-sync-config :=
296    endif
297endif
298
299need-compiler := $(may-sync-config)
300
301ifneq ($(KBUILD_EXTMOD),)
302    may-sync-config :=
303endif
304
305ifeq ($(KBUILD_EXTMOD),)
306    ifneq ($(filter %config,$(MAKECMDGOALS)),)
307        config-build := 1
308        ifneq ($(words $(MAKECMDGOALS)),1)
309            mixed-build := 1
310        endif
311    endif
312endif
313
314# We cannot build single targets and the others at the same time
315ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
316    single-build := 1
317    ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
318        mixed-build := 1
319    endif
320endif
321
322# For "make -j clean all", "make -j mrproper defconfig all", etc.
323ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
324    ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
325        mixed-build := 1
326    endif
327endif
328
329# install and modules_install need also be processed one by one
330ifneq ($(filter install,$(MAKECMDGOALS)),)
331    ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
332        mixed-build := 1
333    endif
334endif
335
336ifdef mixed-build
337# ===========================================================================
338# We're called with mixed targets (*config and build targets).
339# Handle them one by one.
340
341PHONY += $(MAKECMDGOALS) __build_one_by_one
342
343$(MAKECMDGOALS): __build_one_by_one
344	@:
345
346__build_one_by_one:
347	$(Q)set -e; \
348	for i in $(MAKECMDGOALS); do \
349		$(MAKE) -f $(srctree)/Makefile $$i; \
350	done
351
352else # !mixed-build
353
354include $(srctree)/scripts/Kbuild.include
355
356# Read KERNELRELEASE from include/config/kernel.release (if it exists)
357KERNELRELEASE = $(call read-file, include/config/kernel.release)
358KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
359export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
360
361include $(srctree)/scripts/subarch.include
362
363# Cross compiling and selecting different set of gcc/bin-utils
364# ---------------------------------------------------------------------------
365#
366# When performing cross compilation for other architectures ARCH shall be set
367# to the target architecture. (See arch/* for the possibilities).
368# ARCH can be set during invocation of make:
369# make ARCH=arm64
370# Another way is to have ARCH set in the environment.
371# The default ARCH is the host where make is executed.
372
373# CROSS_COMPILE specify the prefix used for all executables used
374# during compilation. Only gcc and related bin-utils executables
375# are prefixed with $(CROSS_COMPILE).
376# CROSS_COMPILE can be set on the command line
377# make CROSS_COMPILE=aarch64-linux-gnu-
378# Alternatively CROSS_COMPILE can be set in the environment.
379# Default value for CROSS_COMPILE is not to prefix executables
380# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
381ARCH		?= $(SUBARCH)
382
383# Architecture as present in compile.h
384UTS_MACHINE 	:= $(ARCH)
385SRCARCH 	:= $(ARCH)
386
387# Additional ARCH settings for x86
388ifeq ($(ARCH),i386)
389        SRCARCH := x86
390endif
391ifeq ($(ARCH),x86_64)
392        SRCARCH := x86
393endif
394
395# Additional ARCH settings for sparc
396ifeq ($(ARCH),sparc32)
397       SRCARCH := sparc
398endif
399ifeq ($(ARCH),sparc64)
400       SRCARCH := sparc
401endif
402
403# Additional ARCH settings for parisc
404ifeq ($(ARCH),parisc64)
405       SRCARCH := parisc
406endif
407
408export cross_compiling :=
409ifneq ($(SRCARCH),$(SUBARCH))
410cross_compiling := 1
411endif
412
413KCONFIG_CONFIG	?= .config
414export KCONFIG_CONFIG
415
416# SHELL used by kbuild
417CONFIG_SHELL := sh
418
419HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
420HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
421HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
422
423ifneq ($(LLVM),)
424ifneq ($(filter %/,$(LLVM)),)
425LLVM_PREFIX := $(LLVM)
426else ifneq ($(filter -%,$(LLVM)),)
427LLVM_SUFFIX := $(LLVM)
428endif
429
430HOSTCC	= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
431HOSTCXX	= $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
432else
433HOSTCC	= gcc
434HOSTCXX	= g++
435endif
436HOSTRUSTC = rustc
437HOSTPKG_CONFIG	= pkg-config
438
439KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
440			 -O2 -fomit-frame-pointer -std=gnu11
441KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
442KBUILD_USERLDFLAGS := $(USERLDFLAGS)
443
444# These flags apply to all Rust code in the tree, including the kernel and
445# host programs.
446export rust_common_flags := --edition=2021 \
447			    -Zbinary_dep_depinfo=y \
448			    -Dunsafe_op_in_unsafe_fn \
449			    -Dnon_ascii_idents \
450			    -Wrust_2018_idioms \
451			    -Wunreachable_pub \
452			    -Wmissing_docs \
453			    -Wrustdoc::missing_crate_level_docs \
454			    -Wclippy::all \
455			    -Wclippy::mut_mut \
456			    -Wclippy::needless_bitwise_bool \
457			    -Wclippy::needless_continue \
458			    -Wclippy::no_mangle_with_rust_abi \
459			    -Wclippy::dbg_macro
460
461KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) \
462		       $(HOSTCFLAGS) -I $(srctree)/scripts/include
463KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS) \
464		       -I $(srctree)/scripts/include
465KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
466			-Zallow-features= $(HOSTRUSTFLAGS)
467KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
468KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
469
470# Make variables (CC, etc...)
471CPP		= $(CC) -E
472ifneq ($(LLVM),)
473CC		= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
474LD		= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
475AR		= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
476NM		= $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
477OBJCOPY		= $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
478OBJDUMP		= $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
479READELF		= $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
480STRIP		= $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
481else
482CC		= $(CROSS_COMPILE)gcc
483LD		= $(CROSS_COMPILE)ld
484AR		= $(CROSS_COMPILE)ar
485NM		= $(CROSS_COMPILE)nm
486OBJCOPY		= $(CROSS_COMPILE)objcopy
487OBJDUMP		= $(CROSS_COMPILE)objdump
488READELF		= $(CROSS_COMPILE)readelf
489STRIP		= $(CROSS_COMPILE)strip
490endif
491RUSTC		= rustc
492RUSTDOC		= rustdoc
493RUSTFMT		= rustfmt
494CLIPPY_DRIVER	= clippy-driver
495BINDGEN		= bindgen
496PAHOLE		= pahole
497RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
498LEX		= flex
499YACC		= bison
500AWK		= awk
501INSTALLKERNEL  := installkernel
502PERL		= perl
503PYTHON3		= python3
504CHECK		= sparse
505BASH		= bash
506KGZIP		= gzip
507KBZIP2		= bzip2
508KLZOP		= lzop
509LZMA		= lzma
510LZ4		= lz4c
511XZ		= xz
512ZSTD		= zstd
513
514CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
515		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
516NOSTDINC_FLAGS :=
517CFLAGS_MODULE   =
518RUSTFLAGS_MODULE =
519AFLAGS_MODULE   =
520LDFLAGS_MODULE  =
521CFLAGS_KERNEL	=
522RUSTFLAGS_KERNEL =
523AFLAGS_KERNEL	=
524LDFLAGS_vmlinux =
525
526# Use USERINCLUDE when you must reference the UAPI directories only.
527USERINCLUDE    := \
528		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
529		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
530		-I$(srctree)/include/uapi \
531		-I$(objtree)/include/generated/uapi \
532                -include $(srctree)/include/linux/compiler-version.h \
533                -include $(srctree)/include/linux/kconfig.h
534
535# Use LINUXINCLUDE when you must reference the include/ directory.
536# Needed to be compatible with the O= option
537LINUXINCLUDE    := \
538		-I$(srctree)/arch/$(SRCARCH)/include \
539		-I$(objtree)/arch/$(SRCARCH)/include/generated \
540		$(if $(building_out_of_srctree),-I$(srctree)/include) \
541		-I$(objtree)/include \
542		$(USERINCLUDE)
543
544KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
545
546KBUILD_CFLAGS :=
547KBUILD_CFLAGS += -std=gnu11
548KBUILD_CFLAGS += -fshort-wchar
549KBUILD_CFLAGS += -funsigned-char
550KBUILD_CFLAGS += -fno-common
551KBUILD_CFLAGS += -fno-PIE
552KBUILD_CFLAGS += -fno-strict-aliasing
553
554KBUILD_CPPFLAGS := -D__KERNEL__
555KBUILD_RUSTFLAGS := $(rust_common_flags) \
556		    -Cpanic=abort -Cembed-bitcode=n -Clto=n \
557		    -Cforce-unwind-tables=n -Ccodegen-units=1 \
558		    -Csymbol-mangling-version=v0 \
559		    -Crelocation-model=static \
560		    -Zfunction-sections=n \
561		    -Wclippy::float_arithmetic
562
563KBUILD_AFLAGS_KERNEL :=
564KBUILD_CFLAGS_KERNEL :=
565KBUILD_RUSTFLAGS_KERNEL :=
566KBUILD_AFLAGS_MODULE  := -DMODULE
567KBUILD_CFLAGS_MODULE  := -DMODULE
568KBUILD_RUSTFLAGS_MODULE := --cfg MODULE
569KBUILD_LDFLAGS_MODULE :=
570KBUILD_LDFLAGS :=
571CLANG_FLAGS :=
572
573ifeq ($(KBUILD_CLIPPY),1)
574	RUSTC_OR_CLIPPY_QUIET := CLIPPY
575	RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER)
576else
577	RUSTC_OR_CLIPPY_QUIET := RUSTC
578	RUSTC_OR_CLIPPY = $(RUSTC)
579endif
580
581ifdef RUST_LIB_SRC
582	export RUST_LIB_SRC
583endif
584
585# Allows the usage of unstable features in stable compilers.
586export RUSTC_BOOTSTRAP := 1
587
588export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
589export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN
590export HOSTRUSTC KBUILD_HOSTRUSTFLAGS
591export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
592export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
593export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
594export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
595export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
596
597export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
598export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
599export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE
600export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
601export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
602export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
603
604# Files to ignore in find ... statements
605
606export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
607			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
608			  -prune -o
609
610# ===========================================================================
611# Rules shared between *config targets and build targets
612
613# Basic helpers built in scripts/basic/
614PHONY += scripts_basic
615scripts_basic:
616	$(Q)$(MAKE) $(build)=scripts/basic
617
618PHONY += outputmakefile
619ifdef building_out_of_srctree
620# Before starting out-of-tree build, make sure the source tree is clean.
621# outputmakefile generates a Makefile in the output directory, if using a
622# separate output directory. This allows convenient use of make in the
623# output directory.
624# At the same time when output Makefile generated, generate .gitignore to
625# ignore whole output directory
626
627quiet_cmd_makefile = GEN     Makefile
628      cmd_makefile = { \
629	echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
630	echo "include $(srctree)/Makefile"; \
631	} > Makefile
632
633outputmakefile:
634	@if [ -f $(srctree)/.config -o \
635		 -d $(srctree)/include/config -o \
636		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
637		echo >&2 "***"; \
638		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
639		echo >&2 "*** in $(abs_srctree)";\
640		echo >&2 "***"; \
641		false; \
642	fi
643	$(Q)ln -fsn $(srctree) source
644	$(call cmd,makefile)
645	$(Q)test -e .gitignore || \
646	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
647endif
648
649# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
650# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
651# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
652# and from include/config/auto.conf.cmd to detect the compiler upgrade.
653CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
654
655ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
656include $(srctree)/scripts/Makefile.clang
657endif
658
659# Include this also for config targets because some architectures need
660# cc-cross-prefix to determine CROSS_COMPILE.
661ifdef need-compiler
662include $(srctree)/scripts/Makefile.compiler
663endif
664
665ifdef config-build
666# ===========================================================================
667# *config targets only - make sure prerequisites are updated, and descend
668# in scripts/kconfig to make the *config target
669
670# Read arch-specific Makefile to set KBUILD_DEFCONFIG as needed.
671# KBUILD_DEFCONFIG may point out an alternative default configuration
672# used for 'make defconfig'
673include $(srctree)/arch/$(SRCARCH)/Makefile
674export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
675
676config: outputmakefile scripts_basic FORCE
677	$(Q)$(MAKE) $(build)=scripts/kconfig $@
678
679%config: outputmakefile scripts_basic FORCE
680	$(Q)$(MAKE) $(build)=scripts/kconfig $@
681
682else #!config-build
683# ===========================================================================
684# Build targets only - this includes vmlinux, arch-specific targets, clean
685# targets and others. In general all targets except *config targets.
686
687# If building an external module we do not care about the all: rule
688# but instead __all depend on modules
689PHONY += all
690ifeq ($(KBUILD_EXTMOD),)
691__all: all
692else
693__all: modules
694endif
695
696targets :=
697
698# Decide whether to build built-in, modular, or both.
699# Normally, just do built-in.
700
701KBUILD_MODULES :=
702KBUILD_BUILTIN := 1
703
704# If we have only "make modules", don't compile built-in objects.
705ifeq ($(MAKECMDGOALS),modules)
706  KBUILD_BUILTIN :=
707endif
708
709# If we have "make <whatever> modules", compile modules
710# in addition to whatever we do anyway.
711# Just "make" or "make all" shall build modules as well
712
713ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
714  KBUILD_MODULES := 1
715endif
716
717ifeq ($(MAKECMDGOALS),)
718  KBUILD_MODULES := 1
719endif
720
721export KBUILD_MODULES KBUILD_BUILTIN
722
723ifdef need-config
724include include/config/auto.conf
725endif
726
727ifeq ($(KBUILD_EXTMOD),)
728# Objects we will link into vmlinux / subdirs we need to visit
729core-y		:=
730drivers-y	:=
731libs-y		:= lib/
732endif # KBUILD_EXTMOD
733
734# The all: target is the default when no target is given on the
735# command line.
736# This allow a user to issue only 'make' to build a kernel including modules
737# Defaults to vmlinux, but the arch makefile usually adds further targets
738all: vmlinux
739
740CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
741ifdef CONFIG_CC_IS_GCC
742CFLAGS_GCOV	+= -fno-tree-loop-im
743endif
744export CFLAGS_GCOV
745
746# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
747ifdef CONFIG_FUNCTION_TRACER
748  CC_FLAGS_FTRACE := -pg
749endif
750
751include $(srctree)/arch/$(SRCARCH)/Makefile
752
753ifdef need-config
754ifdef may-sync-config
755# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
756# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
757# because some architectures define CROSS_COMPILE there.
758include include/config/auto.conf.cmd
759
760$(KCONFIG_CONFIG):
761	@echo >&2 '***'
762	@echo >&2 '*** Configuration file "$@" not found!'
763	@echo >&2 '***'
764	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
765	@echo >&2 '*** "make menuconfig" or "make xconfig").'
766	@echo >&2 '***'
767	@/bin/false
768
769# The actual configuration files used during the build are stored in
770# include/generated/ and include/config/. Update them if .config is newer than
771# include/config/auto.conf (which mirrors .config).
772#
773# This exploits the 'multi-target pattern rule' trick.
774# The syncconfig should be executed only once to make all the targets.
775# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
776#
777# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
778# so you cannot notice that Kconfig is waiting for the user input.
779%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
780	$(Q)$(kecho) "  SYNC    $@"
781	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
782else # !may-sync-config
783# External modules and some install targets need include/generated/autoconf.h
784# and include/config/auto.conf but do not care if they are up-to-date.
785# Use auto.conf to trigger the test
786PHONY += include/config/auto.conf
787
788include/config/auto.conf:
789	@test -e include/generated/autoconf.h -a -e $@ || (		\
790	echo >&2;							\
791	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
792	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
793	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
794	echo >&2 ;							\
795	/bin/false)
796
797endif # may-sync-config
798endif # need-config
799
800KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
801
802ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
803KBUILD_CFLAGS += -O2
804KBUILD_RUSTFLAGS += -Copt-level=2
805else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
806KBUILD_CFLAGS += -Os
807KBUILD_RUSTFLAGS += -Copt-level=s
808endif
809
810# Always set `debug-assertions` and `overflow-checks` because their default
811# depends on `opt-level` and `debug-assertions`, respectively.
812KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
813KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
814
815# Tell gcc to never replace conditional load with a non-conditional one
816ifdef CONFIG_CC_IS_GCC
817# gcc-10 renamed --param=allow-store-data-races=0 to
818# -fno-allow-store-data-races.
819KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
820KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
821endif
822
823ifdef CONFIG_READABLE_ASM
824# Disable optimizations that make assembler listings hard to read.
825# reorder blocks reorders the control in the function
826# ipa clone creates specialized cloned functions
827# partial inlining inlines only parts of functions
828KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
829endif
830
831stackp-flags-y                                    := -fno-stack-protector
832stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
833stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
834
835KBUILD_CFLAGS += $(stackp-flags-y)
836
837KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings
838KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y)
839
840ifdef CONFIG_FRAME_POINTER
841KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
842KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y
843else
844# Some targets (ARM with Thumb2, for example), can't be built with frame
845# pointers.  For those, we don't have FUNCTION_TRACER automatically
846# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
847# incompatible with -fomit-frame-pointer with current GCC, so we don't use
848# -fomit-frame-pointer with FUNCTION_TRACER.
849# In the Rust target specification, "frame-pointer" is set explicitly
850# to "may-omit".
851ifndef CONFIG_FUNCTION_TRACER
852KBUILD_CFLAGS	+= -fomit-frame-pointer
853endif
854endif
855
856# Initialize all stack variables with a 0xAA pattern.
857ifdef CONFIG_INIT_STACK_ALL_PATTERN
858KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
859endif
860
861# Initialize all stack variables with a zero value.
862ifdef CONFIG_INIT_STACK_ALL_ZERO
863KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
864ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
865# https://github.com/llvm/llvm-project/issues/44842
866CC_AUTO_VAR_INIT_ZERO_ENABLER := -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
867export CC_AUTO_VAR_INIT_ZERO_ENABLER
868KBUILD_CFLAGS	+= $(CC_AUTO_VAR_INIT_ZERO_ENABLER)
869endif
870endif
871
872# While VLAs have been removed, GCC produces unreachable stack probes
873# for the randomize_kstack_offset feature. Disable it for all compilers.
874KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
875
876# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
877ifdef CONFIG_ZERO_CALL_USED_REGS
878KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
879endif
880
881ifdef CONFIG_FUNCTION_TRACER
882ifdef CONFIG_FTRACE_MCOUNT_USE_CC
883  CC_FLAGS_FTRACE	+= -mrecord-mcount
884  ifdef CONFIG_HAVE_NOP_MCOUNT
885    ifeq ($(call cc-option-yn, -mnop-mcount),y)
886      CC_FLAGS_FTRACE	+= -mnop-mcount
887      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
888    endif
889  endif
890endif
891ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
892  ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT
893    CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
894  endif
895endif
896ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
897  ifdef CONFIG_HAVE_C_RECORDMCOUNT
898    BUILD_C_RECORDMCOUNT := y
899    export BUILD_C_RECORDMCOUNT
900  endif
901endif
902ifdef CONFIG_HAVE_FENTRY
903  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
904  ifeq ($(call cc-option-yn, -mfentry),y)
905    CC_FLAGS_FTRACE	+= -mfentry
906    CC_FLAGS_USING	+= -DCC_USING_FENTRY
907  endif
908endif
909export CC_FLAGS_FTRACE
910KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
911KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
912endif
913
914# We trigger additional mismatches with less inlining
915ifdef CONFIG_DEBUG_SECTION_MISMATCH
916KBUILD_CFLAGS += -fno-inline-functions-called-once
917endif
918
919# `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
920ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
921KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
922KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
923LDFLAGS_vmlinux += --gc-sections
924endif
925
926ifdef CONFIG_SHADOW_CALL_STACK
927ifndef CONFIG_DYNAMIC_SCS
928CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
929KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
930endif
931export CC_FLAGS_SCS
932endif
933
934ifdef CONFIG_LTO_CLANG
935ifdef CONFIG_LTO_CLANG_THIN
936CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
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
944endif
945
946ifdef CONFIG_LTO
947KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
948KBUILD_AFLAGS	+= -fno-lto
949export CC_FLAGS_LTO
950endif
951
952ifdef CONFIG_CFI_CLANG
953CC_FLAGS_CFI	:= -fsanitize=kcfi
954KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
955export CC_FLAGS_CFI
956endif
957
958# Architectures can define flags to add/remove for floating-point support
959CC_FLAGS_FPU	+= -D_LINUX_FPU_COMPILATION_UNIT
960export CC_FLAGS_FPU
961export CC_FLAGS_NO_FPU
962
963ifneq ($(CONFIG_FUNCTION_ALIGNMENT),0)
964# Set the minimal function alignment. Use the newer GCC option
965# -fmin-function-alignment if it is available, or fall back to -falign-funtions.
966# See also CONFIG_CC_HAS_SANE_FUNCTION_ALIGNMENT.
967ifdef CONFIG_CC_HAS_MIN_FUNCTION_ALIGNMENT
968KBUILD_CFLAGS += -fmin-function-alignment=$(CONFIG_FUNCTION_ALIGNMENT)
969else
970KBUILD_CFLAGS += -falign-functions=$(CONFIG_FUNCTION_ALIGNMENT)
971endif
972endif
973
974# arch Makefile may override CC so keep this after arch Makefile is included
975NOSTDINC_FLAGS += -nostdinc
976
977# To gain proper coverage for CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE,
978# the kernel uses only C99 flexible arrays for dynamically sized trailing
979# arrays. Enforce this for everything that may examine structure sizes and
980# perform bounds checking.
981KBUILD_CFLAGS += $(call cc-option, -fstrict-flex-arrays=3)
982
983#Currently, disable -Wstringop-overflow for GCC 11, globally.
984KBUILD_CFLAGS-$(CONFIG_CC_NO_STRINGOP_OVERFLOW) += $(call cc-option, -Wno-stringop-overflow)
985KBUILD_CFLAGS-$(CONFIG_CC_STRINGOP_OVERFLOW) += $(call cc-option, -Wstringop-overflow)
986
987# disable invalid "can't wrap" optimizations for signed / pointers
988KBUILD_CFLAGS	+= -fno-strict-overflow
989
990# Make sure -fstack-check isn't enabled (like gentoo apparently did)
991KBUILD_CFLAGS  += -fno-stack-check
992
993# conserve stack if available
994ifdef CONFIG_CC_IS_GCC
995KBUILD_CFLAGS   += -fconserve-stack
996endif
997
998# change __FILE__ to the relative path from the srctree
999KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1000
1001# include additional Makefiles when needed
1002include-y			:= scripts/Makefile.extrawarn
1003include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
1004include-$(CONFIG_DEBUG_INFO_BTF)+= scripts/Makefile.btf
1005include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1006include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1007include-$(CONFIG_KMSAN)		+= scripts/Makefile.kmsan
1008include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1009include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1010include-$(CONFIG_RANDSTRUCT)	+= scripts/Makefile.randstruct
1011include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1012
1013include $(addprefix $(srctree)/, $(include-y))
1014
1015# scripts/Makefile.gcc-plugins is intentionally included last.
1016# Do not add $(call cc-option,...) below this line. When you build the kernel
1017# from the clean source tree, the GCC plugins do not exist at this point.
1018
1019# Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
1020KBUILD_CPPFLAGS += $(KCPPFLAGS)
1021KBUILD_AFLAGS   += $(KAFLAGS)
1022KBUILD_CFLAGS   += $(KCFLAGS)
1023KBUILD_RUSTFLAGS += $(KRUSTFLAGS)
1024
1025KBUILD_LDFLAGS_MODULE += --build-id=sha1
1026LDFLAGS_vmlinux += --build-id=sha1
1027
1028KBUILD_LDFLAGS	+= -z noexecstack
1029ifeq ($(CONFIG_LD_IS_BFD),y)
1030KBUILD_LDFLAGS	+= $(call ld-option,--no-warn-rwx-segments)
1031endif
1032
1033ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1034LDFLAGS_vmlinux	+= -X
1035endif
1036
1037ifeq ($(CONFIG_RELR),y)
1038# ld.lld before 15 did not support -z pack-relative-relocs.
1039LDFLAGS_vmlinux	+= $(call ld-option,--pack-dyn-relocs=relr,-z pack-relative-relocs)
1040endif
1041
1042# We never want expected sections to be placed heuristically by the
1043# linker. All sections should be explicitly named in the linker script.
1044ifdef CONFIG_LD_ORPHAN_WARN
1045LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
1046endif
1047
1048# Align the bit size of userspace programs with the kernel
1049KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1050KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1051
1052# make the checker run with the right architecture
1053CHECKFLAGS += --arch=$(ARCH)
1054
1055# insure the checker run with the right endianness
1056CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1057
1058# the checker needs the correct machine size
1059CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1060
1061# Default kernel image to build when no specific target is given.
1062# KBUILD_IMAGE may be overruled on the command line or
1063# set in the environment
1064# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1065# this default value
1066export KBUILD_IMAGE ?= vmlinux
1067
1068#
1069# INSTALL_PATH specifies where to place the updated kernel and system map
1070# images. Default is /boot, but you can set it to other values
1071export	INSTALL_PATH ?= /boot
1072
1073#
1074# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1075# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1076# an argument if needed. Otherwise it defaults to the kernel install path
1077#
1078export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1079
1080#
1081# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1082# relocations required by build roots.  This is not defined in the
1083# makefile but the argument can be passed to make if needed.
1084#
1085
1086MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1087export MODLIB
1088
1089PHONY += prepare0
1090
1091export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1092export MODORDER := $(extmod_prefix)modules.order
1093export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1094
1095ifeq ($(KBUILD_EXTMOD),)
1096
1097build-dir	:= .
1098clean-dirs	:= $(sort . Documentation \
1099		     $(patsubst %/,%,$(filter %/, $(core-) \
1100			$(drivers-) $(libs-))))
1101
1102export ARCH_CORE	:= $(core-y)
1103export ARCH_LIB		:= $(filter %/, $(libs-y))
1104export ARCH_DRIVERS	:= $(drivers-y) $(drivers-m)
1105# Externally visible symbols (used by link-vmlinux.sh)
1106
1107KBUILD_VMLINUX_OBJS := ./built-in.a
1108ifdef CONFIG_MODULES
1109KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1110KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1111else
1112KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1113endif
1114
1115export KBUILD_VMLINUX_LIBS
1116export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1117
1118ifdef CONFIG_TRIM_UNUSED_KSYMS
1119# For the kernel to actually contain only the needed exported symbols,
1120# we have to build modules as well to determine what those symbols are.
1121KBUILD_MODULES := 1
1122endif
1123
1124# '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
1125quiet_cmd_ar_vmlinux.a = AR      $@
1126      cmd_ar_vmlinux.a = \
1127	rm -f $@; \
1128	$(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
1129	$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
1130
1131targets += vmlinux.a
1132vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
1133	$(call if_changed,ar_vmlinux.a)
1134
1135PHONY += vmlinux_o
1136vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
1137	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
1138
1139vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
1140	@:
1141
1142PHONY += vmlinux
1143# LDFLAGS_vmlinux in the top Makefile defines linker flags for the top vmlinux,
1144# not for decompressors. LDFLAGS_vmlinux in arch/*/boot/compressed/Makefile is
1145# unrelated; the decompressors just happen to have the same base name,
1146# arch/*/boot/compressed/vmlinux.
1147# Export LDFLAGS_vmlinux only to scripts/Makefile.vmlinux.
1148#
1149# _LDFLAGS_vmlinux is a workaround for the 'private export' bug:
1150#   https://savannah.gnu.org/bugs/?61463
1151# For Make > 4.4, the following simple code will work:
1152#  vmlinux: private export LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1153vmlinux: private _LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1154vmlinux: export LDFLAGS_vmlinux = $(_LDFLAGS_vmlinux)
1155vmlinux: vmlinux.o $(KBUILD_LDS) modpost
1156	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux
1157
1158# The actual objects are generated when descending,
1159# make sure no implicit rule kicks in
1160$(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;
1161
1162ifeq ($(origin KERNELRELEASE),file)
1163filechk_kernel.release = $(srctree)/scripts/setlocalversion $(srctree)
1164else
1165filechk_kernel.release = echo $(KERNELRELEASE)
1166endif
1167
1168# Store (new) KERNELRELEASE string in include/config/kernel.release
1169include/config/kernel.release: FORCE
1170	$(call filechk,kernel.release)
1171
1172# Additional helpers built in scripts/
1173# Carefully list dependencies so we do not try to build scripts twice
1174# in parallel
1175PHONY += scripts
1176scripts: scripts_basic scripts_dtc
1177	$(Q)$(MAKE) $(build)=$(@)
1178
1179# Things we need to do before we recursively start building the kernel
1180# or the modules are listed in "prepare".
1181# A multi level approach is used. prepareN is processed before prepareN-1.
1182# archprepare is used in arch Makefiles and when processed asm symlink,
1183# version.h and scripts_basic is processed / created.
1184
1185PHONY += prepare archprepare
1186
1187archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1188	asm-generic $(version_h) include/generated/utsrelease.h \
1189	include/generated/compile.h include/generated/autoconf.h remove-stale-files
1190
1191prepare0: archprepare
1192	$(Q)$(MAKE) $(build)=scripts/mod
1193	$(Q)$(MAKE) $(build)=. prepare
1194
1195# All the preparing..
1196prepare: prepare0
1197ifdef CONFIG_RUST
1198	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
1199	$(Q)$(MAKE) $(build)=rust
1200endif
1201
1202PHONY += remove-stale-files
1203remove-stale-files:
1204	$(Q)$(srctree)/scripts/remove-stale-files
1205
1206# Support for using generic headers in asm-generic
1207asm-generic := -f $(srctree)/scripts/Makefile.asm-headers obj
1208
1209PHONY += asm-generic uapi-asm-generic
1210asm-generic: uapi-asm-generic
1211	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1212	generic=include/asm-generic
1213uapi-asm-generic:
1214	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1215	generic=include/uapi/asm-generic
1216
1217# Generate some files
1218# ---------------------------------------------------------------------------
1219
1220# KERNELRELEASE can change from a few different places, meaning version.h
1221# needs to be updated, so this check is forced on all builds
1222
1223uts_len := 64
1224define filechk_utsrelease.h
1225	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1226	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1227	  exit 1;                                                         \
1228	fi;                                                               \
1229	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1230endef
1231
1232define filechk_version.h
1233	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1234		echo \#define LINUX_VERSION_CODE $(shell                 \
1235		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1236	else                                                             \
1237		echo \#define LINUX_VERSION_CODE $(shell                 \
1238		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1239	fi;                                                              \
1240	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1241	((c) > 255 ? 255 : (c)))';                                       \
1242	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1243	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1244	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1245endef
1246
1247$(version_h): private PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1248$(version_h): private SUBLEVEL := $(or $(SUBLEVEL), 0)
1249$(version_h): FORCE
1250	$(call filechk,version.h)
1251
1252include/generated/utsrelease.h: include/config/kernel.release FORCE
1253	$(call filechk,utsrelease.h)
1254
1255filechk_compile.h = $(srctree)/scripts/mkcompile_h \
1256	"$(UTS_MACHINE)" "$(CONFIG_CC_VERSION_TEXT)" "$(LD)"
1257
1258include/generated/compile.h: FORCE
1259	$(call filechk,compile.h)
1260
1261PHONY += headerdep
1262headerdep:
1263	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1264	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1265
1266# ---------------------------------------------------------------------------
1267# Kernel headers
1268
1269#Default location for installed headers
1270export INSTALL_HDR_PATH = $(objtree)/usr
1271
1272quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1273      cmd_headers_install = \
1274	mkdir -p $(INSTALL_HDR_PATH); \
1275	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1276	usr/include $(INSTALL_HDR_PATH)
1277
1278PHONY += headers_install
1279headers_install: headers
1280	$(call cmd,headers_install)
1281
1282PHONY += archheaders archscripts
1283
1284hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1285
1286PHONY += headers
1287headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1288	$(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML))
1289	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1290	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1291
1292ifdef CONFIG_HEADERS_INSTALL
1293prepare: headers
1294endif
1295
1296PHONY += scripts_unifdef
1297scripts_unifdef: scripts_basic
1298	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1299
1300# ---------------------------------------------------------------------------
1301# Install
1302
1303# Many distributions have the custom install script, /sbin/installkernel.
1304# If DKMS is installed, 'make install' will eventually recurse back
1305# to this Makefile to build and install external modules.
1306# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1307
1308quiet_cmd_install = INSTALL $(INSTALL_PATH)
1309      cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1310
1311# ---------------------------------------------------------------------------
1312# vDSO install
1313
1314PHONY += vdso_install
1315vdso_install: export INSTALL_FILES = $(vdso-install-y)
1316vdso_install:
1317	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vdsoinst
1318
1319# ---------------------------------------------------------------------------
1320# Tools
1321
1322ifdef CONFIG_OBJTOOL
1323prepare: tools/objtool
1324endif
1325
1326ifdef CONFIG_BPF
1327ifdef CONFIG_DEBUG_INFO_BTF
1328prepare: tools/bpf/resolve_btfids
1329endif
1330endif
1331
1332# The tools build system is not a part of Kbuild and tends to introduce
1333# its own unique issues. If you need to integrate a new tool into Kbuild,
1334# please consider locating that tool outside the tools/ tree and using the
1335# standard Kbuild "hostprogs" syntax instead of adding a new tools/* entry
1336# here. See Documentation/kbuild/makefiles.rst for details.
1337
1338PHONY += resolve_btfids_clean
1339
1340resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1341
1342# tools/bpf/resolve_btfids directory might not exist
1343# in output directory, skip its clean in that case
1344resolve_btfids_clean:
1345ifneq ($(wildcard $(resolve_btfids_O)),)
1346	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1347endif
1348
1349# Clear a bunch of variables before executing the submake
1350ifeq ($(quiet),silent_)
1351tools_silent=s
1352endif
1353
1354tools/: FORCE
1355	$(Q)mkdir -p $(objtree)/tools
1356	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1357
1358tools/%: FORCE
1359	$(Q)mkdir -p $(objtree)/tools
1360	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1361
1362# ---------------------------------------------------------------------------
1363# Kernel selftest
1364
1365PHONY += kselftest
1366kselftest: headers
1367	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1368
1369kselftest-%: headers FORCE
1370	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1371
1372PHONY += kselftest-merge
1373kselftest-merge:
1374	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1375	$(Q)find $(srctree)/tools/testing/selftests -name config -o -name config.$(UTS_MACHINE) | \
1376		xargs $(srctree)/scripts/kconfig/merge_config.sh -y -m $(objtree)/.config
1377	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1378
1379# ---------------------------------------------------------------------------
1380# Devicetree files
1381
1382ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1383dtstree := arch/$(SRCARCH)/boot/dts
1384endif
1385
1386ifneq ($(dtstree),)
1387
1388%.dtb: dtbs_prepare
1389	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1390
1391%.dtbo: dtbs_prepare
1392	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1393
1394PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1395dtbs: dtbs_prepare
1396	$(Q)$(MAKE) $(build)=$(dtstree) need-dtbslist=1
1397
1398# include/config/kernel.release is actually needed when installing DTBs because
1399# INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1400# dtbs_install depend on it as dtbs_install may run as root.
1401dtbs_prepare: include/config/kernel.release scripts_dtc
1402
1403ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1404export CHECK_DTBS=y
1405endif
1406
1407ifneq ($(CHECK_DTBS),)
1408dtbs_prepare: dt_binding_schemas
1409endif
1410
1411dtbs_check: dtbs
1412
1413dtbs_install:
1414	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.dtbinst obj=$(dtstree)
1415
1416ifdef CONFIG_OF_EARLY_FLATTREE
1417all: dtbs
1418endif
1419
1420endif
1421
1422PHONY += scripts_dtc
1423scripts_dtc: scripts_basic
1424	$(Q)$(MAKE) $(build)=scripts/dtc
1425
1426ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1427export CHECK_DTBS=y
1428endif
1429
1430PHONY += dt_binding_check dt_binding_schemas
1431dt_binding_check: dt_binding_schemas scripts_dtc
1432	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1433
1434dt_binding_schemas:
1435	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1436
1437PHONY += dt_compatible_check
1438dt_compatible_check: dt_binding_schemas
1439	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1440
1441# ---------------------------------------------------------------------------
1442# Modules
1443
1444ifdef CONFIG_MODULES
1445
1446# By default, build modules as well
1447
1448all: modules
1449
1450# When we're building modules with modversions, we need to consider
1451# the built-in objects during the descend as well, in order to
1452# make sure the checksums are up to date before we record them.
1453ifdef CONFIG_MODVERSIONS
1454  KBUILD_BUILTIN := 1
1455endif
1456
1457# Build modules
1458#
1459
1460# *.ko are usually independent of vmlinux, but CONFIG_DEBUG_INFO_BTF_MODULES
1461# is an exception.
1462ifdef CONFIG_DEBUG_INFO_BTF_MODULES
1463KBUILD_BUILTIN := 1
1464modules: vmlinux
1465endif
1466
1467modules: modules_prepare
1468
1469# Target to prepare building external modules
1470modules_prepare: prepare
1471	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1472
1473endif # CONFIG_MODULES
1474
1475###
1476# Cleaning is done on three levels.
1477# make clean     Delete most generated files
1478#                Leave enough to build external modules
1479# make mrproper  Delete the current configuration, and all generated files
1480# make distclean Remove editor backup files, patch leftover files and the like
1481
1482# Directories & files removed with 'make clean'
1483CLEAN_FILES += vmlinux.symvers modules-only.symvers \
1484	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1485	       compile_commands.json rust/test \
1486	       rust-project.json .vmlinux.objs .vmlinux.export.c
1487
1488# Directories & files removed with 'make mrproper'
1489MRPROPER_FILES += include/config include/generated          \
1490		  arch/$(SRCARCH)/include/generated .objdiff \
1491		  debian snap tar-install PKGBUILD pacman \
1492		  .config .config.old .version \
1493		  Module.symvers \
1494		  certs/signing_key.pem \
1495		  certs/x509.genkey \
1496		  vmlinux-gdb.py \
1497		  rpmbuild \
1498		  rust/libmacros.so
1499
1500# clean - Delete most, but leave enough to build external modules
1501#
1502clean: private rm-files := $(CLEAN_FILES)
1503
1504PHONY += archclean vmlinuxclean
1505
1506vmlinuxclean:
1507	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1508	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1509
1510clean: archclean vmlinuxclean resolve_btfids_clean
1511
1512# mrproper - Delete all generated files, including .config
1513#
1514mrproper: private rm-files := $(MRPROPER_FILES)
1515mrproper-dirs      := $(addprefix _mrproper_,scripts)
1516
1517PHONY += $(mrproper-dirs) mrproper
1518$(mrproper-dirs):
1519	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1520
1521mrproper: clean $(mrproper-dirs)
1522	$(call cmd,rmfiles)
1523	@find . $(RCS_FIND_IGNORE) \
1524		\( -name '*.rmeta' \) \
1525		-type f -print | xargs rm -f
1526
1527# distclean
1528#
1529PHONY += distclean
1530
1531distclean: mrproper
1532	@find . $(RCS_FIND_IGNORE) \
1533		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1534		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1535		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1536		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1537		-type f -print | xargs rm -f
1538
1539
1540# Packaging of the kernel to various formats
1541# ---------------------------------------------------------------------------
1542
1543%src-pkg: FORCE
1544	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1545%pkg: include/config/kernel.release FORCE
1546	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1547
1548# Brief documentation of the typical targets used
1549# ---------------------------------------------------------------------------
1550
1551boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1552boards := $(sort $(notdir $(boards)))
1553board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1554board-dirs := $(sort $(notdir $(board-dirs:/=)))
1555
1556PHONY += help
1557help:
1558	@echo  'Cleaning targets:'
1559	@echo  '  clean		  - Remove most generated files but keep the config and'
1560	@echo  '                    enough build support to build external modules'
1561	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1562	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1563	@echo  ''
1564	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1565	@echo  ''
1566	@echo  'Other generic targets:'
1567	@echo  '  all		  - Build all targets marked with [*]'
1568	@echo  '* vmlinux	  - Build the bare kernel'
1569	@echo  '* modules	  - Build all modules'
1570	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1571	@echo  '  vdso_install    - Install unstripped vdso to INSTALL_MOD_PATH (default: /)'
1572	@echo  '  dir/            - Build all files in dir and below'
1573	@echo  '  dir/file.[ois]  - Build specified target only'
1574	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1575	@echo  '                    (requires compiler support for LLVM assembly generation)'
1576	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1577	@echo  '                    (requires a recent binutils and recent build (System.map))'
1578	@echo  '  dir/file.ko     - Build module including final link'
1579	@echo  '  modules_prepare - Set up for building external modules'
1580	@echo  '  tags/TAGS	  - Generate tags file for editors'
1581	@echo  '  cscope	  - Generate cscope index'
1582	@echo  '  gtags           - Generate GNU GLOBAL index'
1583	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1584	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1585	@echo  '  image_name	  - Output the image name (use with make -s)'
1586	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1587	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1588	 echo  ''
1589	@echo  'Static analysers:'
1590	@echo  '  checkstack      - Generate a list of stack hogs and consider all functions'
1591	@echo  '                    with a stack size larger than MINSTACKSIZE (default: 100)'
1592	@echo  '  versioncheck    - Sanity check on version.h usage'
1593	@echo  '  includecheck    - Check for duplicate included header files'
1594	@echo  '  export_report   - List the usages of all exported symbols'
1595	@echo  '  headerdep       - Detect inclusion cycles in headers'
1596	@echo  '  coccicheck      - Check with Coccinelle'
1597	@echo  '  clang-analyzer  - Check with clang static analyzer'
1598	@echo  '  clang-tidy      - Check with clang-tidy'
1599	@echo  ''
1600	@echo  'Tools:'
1601	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1602	@echo  ''
1603	@echo  'Kernel selftest:'
1604	@echo  '  kselftest         - Build and run kernel selftest'
1605	@echo  '                      Build, install, and boot kernel before'
1606	@echo  '                      running kselftest on it'
1607	@echo  '                      Run as root for full coverage'
1608	@echo  '  kselftest-all     - Build kernel selftest'
1609	@echo  '  kselftest-install - Build and install kernel selftest'
1610	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1611	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1612	@echo  '		      kselftest to existing .config.'
1613	@echo  ''
1614	@echo  'Rust targets:'
1615	@echo  '  rustavailable   - Checks whether the Rust toolchain is'
1616	@echo  '		    available and, if not, explains why.'
1617	@echo  '  rustfmt	  - Reformat all the Rust code in the kernel'
1618	@echo  '  rustfmtcheck	  - Checks if all the Rust code in the kernel'
1619	@echo  '		    is formatted, printing a diff otherwise.'
1620	@echo  '  rustdoc	  - Generate Rust documentation'
1621	@echo  '		    (requires kernel .config)'
1622	@echo  '  rusttest        - Runs the Rust tests'
1623	@echo  '                    (requires kernel .config; downloads external repos)'
1624	@echo  '  rust-analyzer	  - Generate rust-project.json rust-analyzer support file'
1625	@echo  '		    (requires kernel .config)'
1626	@echo  '  dir/file.[os]   - Build specified target only'
1627	@echo  '  dir/file.rsi    - Build macro expanded source, similar to C preprocessing.'
1628	@echo  '                    Run with RUSTFMT=n to skip reformatting if needed.'
1629	@echo  '                    The output is not intended to be compilable.'
1630	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1631	@echo  ''
1632	@$(if $(dtstree), \
1633		echo 'Devicetree:'; \
1634		echo '* dtbs               - Build device tree blobs for enabled boards'; \
1635		echo '  dtbs_install       - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1636		echo '  dt_binding_check   - Validate device tree binding documents and examples'; \
1637		echo '  dt_binding_schema  - Build processed device tree binding schemas'; \
1638		echo '  dtbs_check         - Validate device tree source files';\
1639		echo '')
1640
1641	@echo 'Userspace tools targets:'
1642	@echo '  use "make tools/help"'
1643	@echo '  or  "cd tools; make help"'
1644	@echo  ''
1645	@echo  'Kernel packaging:'
1646	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1647	@echo  ''
1648	@echo  'Documentation targets:'
1649	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1650	@echo  ''
1651	@echo  'Architecture-specific targets ($(SRCARCH)):'
1652	@$(or $(archhelp),\
1653		echo '  No architecture-specific help defined for $(SRCARCH)')
1654	@echo  ''
1655	@$(if $(boards), \
1656		$(foreach b, $(boards), \
1657		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1658		echo '')
1659	@$(if $(board-dirs), \
1660		$(foreach b, $(board-dirs), \
1661		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1662		printf "  %-16s - Show all of the above\\n" help-boards; \
1663		echo '')
1664
1665	@echo  '  make V=n   [targets] 1: verbose build'
1666	@echo  '                       2: give reason for rebuild of target'
1667	@echo  '                       V=1 and V=2 can be combined with V=12'
1668	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1669	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1670	@echo  '                       (sparse by default)'
1671	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1672	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1673	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3,c,e where'
1674	@echo  '		1: warnings which may be relevant and do not occur too often'
1675	@echo  '		2: warnings which occur quite often but may still be relevant'
1676	@echo  '		3: more obscure warnings, can most likely be ignored'
1677	@echo  '		c: extra checks in the configuration stage (Kconfig)'
1678	@echo  '		e: warnings are being treated as errors'
1679	@echo  '		Multiple levels can be combined with W=12 or W=123'
1680	@$(if $(dtstree), \
1681		echo '  make CHECK_DTBS=1 [targets] Check all generated dtb files against schema'; \
1682		echo '         This can be applied both to "dtbs" and to individual "foo.dtb" targets' ; \
1683		)
1684	@echo  ''
1685	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1686	@echo  'For further info see the ./README file'
1687
1688
1689help-board-dirs := $(addprefix help-,$(board-dirs))
1690
1691help-boards: $(help-board-dirs)
1692
1693boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1694
1695$(help-board-dirs): help-%:
1696	@echo  'Architecture-specific targets ($(SRCARCH) $*):'
1697	@$(if $(boards-per-dir), \
1698		$(foreach b, $(boards-per-dir), \
1699		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1700		echo '')
1701
1702
1703# Documentation targets
1704# ---------------------------------------------------------------------------
1705DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1706	       linkcheckdocs dochelp refcheckdocs texinfodocs infodocs
1707PHONY += $(DOC_TARGETS)
1708$(DOC_TARGETS):
1709	$(Q)$(MAKE) $(build)=Documentation $@
1710
1711
1712# Rust targets
1713# ---------------------------------------------------------------------------
1714
1715# "Is Rust available?" target
1716PHONY += rustavailable
1717rustavailable:
1718	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh && echo "Rust is available!"
1719
1720# Documentation target
1721#
1722# Using the singular to avoid running afoul of `no-dot-config-targets`.
1723PHONY += rustdoc
1724rustdoc: prepare
1725	$(Q)$(MAKE) $(build)=rust $@
1726
1727# Testing target
1728PHONY += rusttest
1729rusttest: prepare
1730	$(Q)$(MAKE) $(build)=rust $@
1731
1732# Formatting targets
1733PHONY += rustfmt rustfmtcheck
1734
1735# We skip `rust/alloc` since we want to minimize the diff w.r.t. upstream.
1736#
1737# We match using absolute paths since `find` does not resolve them
1738# when matching, which is a problem when e.g. `srctree` is `..`.
1739# We `grep` afterwards in order to remove the directory entry itself.
1740rustfmt:
1741	$(Q)find $(abs_srctree) -type f -name '*.rs' \
1742		-o -path $(abs_srctree)/rust/alloc -prune \
1743		-o -path $(abs_objtree)/rust/test -prune \
1744		| grep -Fv $(abs_srctree)/rust/alloc \
1745		| grep -Fv $(abs_objtree)/rust/test \
1746		| grep -Fv generated \
1747		| xargs $(RUSTFMT) $(rustfmt_flags)
1748
1749rustfmtcheck: rustfmt_flags = --check
1750rustfmtcheck: rustfmt
1751
1752# Misc
1753# ---------------------------------------------------------------------------
1754
1755PHONY += misc-check
1756misc-check:
1757	$(Q)$(srctree)/scripts/misc-check
1758
1759all: misc-check
1760
1761PHONY += scripts_gdb
1762scripts_gdb: prepare0
1763	$(Q)$(MAKE) $(build)=scripts/gdb
1764	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1765
1766ifdef CONFIG_GDB_SCRIPTS
1767all: scripts_gdb
1768endif
1769
1770else # KBUILD_EXTMOD
1771
1772filechk_kernel.release = echo $(KERNELRELEASE)
1773
1774###
1775# External module support.
1776# When building external modules the kernel used as basis is considered
1777# read-only, and no consistency checks are made and the make
1778# system is not used on the basis kernel. If updates are required
1779# in the basis kernel ordinary make commands (without M=...) must be used.
1780
1781# We are always building only modules.
1782KBUILD_BUILTIN :=
1783KBUILD_MODULES := 1
1784
1785build-dir := $(KBUILD_EXTMOD)
1786
1787compile_commands.json: $(extmod_prefix)compile_commands.json
1788PHONY += compile_commands.json
1789
1790clean-dirs := $(KBUILD_EXTMOD)
1791clean: private rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1792	$(KBUILD_EXTMOD)/compile_commands.json
1793
1794PHONY += prepare
1795# now expand this into a simple variable to reduce the cost of shell evaluations
1796prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1797prepare:
1798	@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1799		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1800		echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1801		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1802	fi
1803
1804PHONY += help
1805help:
1806	@echo  '  Building external modules.'
1807	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1808	@echo  ''
1809	@echo  '  modules         - default target, build the module(s)'
1810	@echo  '  modules_install - install the module'
1811	@echo  '  clean           - remove generated files in module directory only'
1812	@echo  '  rust-analyzer	  - generate rust-project.json rust-analyzer support file'
1813	@echo  ''
1814
1815ifndef CONFIG_MODULES
1816modules modules_install: __external_modules_error
1817__external_modules_error:
1818	@echo >&2 '***'
1819	@echo >&2 '*** The present kernel disabled CONFIG_MODULES.'
1820	@echo >&2 '*** You cannot build or install external modules.'
1821	@echo >&2 '***'
1822	@false
1823endif
1824
1825endif # KBUILD_EXTMOD
1826
1827# ---------------------------------------------------------------------------
1828# Modules
1829
1830PHONY += modules modules_install modules_sign modules_prepare
1831
1832modules_install:
1833	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst \
1834	sign-only=$(if $(filter modules_install,$(MAKECMDGOALS)),,y)
1835
1836ifeq ($(CONFIG_MODULE_SIG),y)
1837# modules_sign is a subset of modules_install.
1838# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1839modules_sign: modules_install
1840	@:
1841else
1842modules_sign:
1843	@echo >&2 '***'
1844	@echo >&2 '*** CONFIG_MODULE_SIG is disabled. You cannot sign modules.'
1845	@echo >&2 '***'
1846	@false
1847endif
1848
1849ifdef CONFIG_MODULES
1850
1851$(MODORDER): $(build-dir)
1852	@:
1853
1854# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
1855# This is solely useful to speed up test compiles.
1856modules: modpost
1857ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1858	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1859endif
1860
1861PHONY += modules_check
1862modules_check: $(MODORDER)
1863	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1864
1865else # CONFIG_MODULES
1866
1867modules:
1868	@:
1869
1870KBUILD_MODULES :=
1871
1872endif # CONFIG_MODULES
1873
1874PHONY += modpost
1875modpost: $(if $(single-build),, $(if $(KBUILD_BUILTIN), vmlinux.o)) \
1876	 $(if $(KBUILD_MODULES), modules_check)
1877	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1878
1879# Single targets
1880# ---------------------------------------------------------------------------
1881# To build individual files in subdirectories, you can do like this:
1882#
1883#   make foo/bar/baz.s
1884#
1885# The supported suffixes for single-target are listed in 'single-targets'
1886#
1887# To build only under specific subdirectories, you can do like this:
1888#
1889#   make foo/bar/baz/
1890
1891ifdef single-build
1892
1893# .ko is special because modpost is needed
1894single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1895single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
1896		$(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
1897
1898$(single-ko): single_modules
1899	@:
1900$(single-no-ko): $(build-dir)
1901	@:
1902
1903# Remove MODORDER when done because it is not the real one.
1904PHONY += single_modules
1905single_modules: $(single-no-ko) modules_prepare
1906	$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$(m:%.ko=%.o);) } > $(MODORDER)
1907	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1908ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1909	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1910endif
1911	$(Q)rm -f $(MODORDER)
1912
1913single-goals := $(addprefix $(build-dir)/, $(single-no-ko))
1914
1915KBUILD_MODULES := 1
1916
1917endif
1918
1919# Preset locale variables to speed up the build process. Limit locale
1920# tweaks to this spot to avoid wrong language settings when running
1921# make menuconfig etc.
1922# Error messages still appears in the original language
1923PHONY += $(build-dir)
1924$(build-dir): prepare
1925	$(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)
1926
1927clean-dirs := $(addprefix _clean_, $(clean-dirs))
1928PHONY += $(clean-dirs) clean
1929$(clean-dirs):
1930	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1931
1932clean: $(clean-dirs)
1933	$(call cmd,rmfiles)
1934	@find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1935		\( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
1936		-o -name '*.ko.*' \
1937		-o -name '*.dtb' -o -name '*.dtbo' \
1938		-o -name '*.dtb.S' -o -name '*.dtbo.S' \
1939		-o -name '*.dt.yaml' -o -name 'dtbs-list' \
1940		-o -name '*.dwo' -o -name '*.lst' \
1941		-o -name '*.su' -o -name '*.mod' \
1942		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1943		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
1944		-o -name '*.asn1.[ch]' \
1945		-o -name '*.symtypes' -o -name 'modules.order' \
1946		-o -name '*.c.[012]*.*' \
1947		-o -name '*.ll' \
1948		-o -name '*.gcno' \
1949		-o -name '*.*.symversions' \) -type f -print \
1950		-o -name '.tmp_*' -print \
1951		| xargs rm -rf
1952
1953# Generate tags for editors
1954# ---------------------------------------------------------------------------
1955quiet_cmd_tags = GEN     $@
1956      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1957
1958tags TAGS cscope gtags: FORCE
1959	$(call cmd,tags)
1960
1961# Generate rust-project.json (a file that describes the structure of non-Cargo
1962# Rust projects) for rust-analyzer (an implementation of the Language Server
1963# Protocol).
1964PHONY += rust-analyzer
1965rust-analyzer:
1966	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
1967	$(Q)$(MAKE) $(build)=rust $@
1968
1969# Script to generate missing namespace dependencies
1970# ---------------------------------------------------------------------------
1971
1972PHONY += nsdeps
1973nsdeps: export KBUILD_NSDEPS=1
1974nsdeps: modules
1975	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1976
1977# Clang Tooling
1978# ---------------------------------------------------------------------------
1979
1980quiet_cmd_gen_compile_commands = GEN     $@
1981      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1982
1983$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1984	$(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS)) \
1985	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1986	$(call if_changed,gen_compile_commands)
1987
1988targets += $(extmod_prefix)compile_commands.json
1989
1990PHONY += clang-tidy clang-analyzer
1991
1992ifdef CONFIG_CC_IS_CLANG
1993quiet_cmd_clang_tools = CHECK   $<
1994      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1995
1996clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
1997	$(call cmd,clang_tools)
1998else
1999clang-tidy clang-analyzer:
2000	@echo "$@ requires CC=clang" >&2
2001	@false
2002endif
2003
2004# Scripts to check various things for consistency
2005# ---------------------------------------------------------------------------
2006
2007PHONY += includecheck versioncheck coccicheck export_report
2008
2009includecheck:
2010	find $(srctree)/* $(RCS_FIND_IGNORE) \
2011		-name '*.[hcS]' -type f -print | sort \
2012		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
2013
2014versioncheck:
2015	find $(srctree)/* $(RCS_FIND_IGNORE) \
2016		-name '*.[hcS]' -type f -print | sort \
2017		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
2018
2019coccicheck:
2020	$(Q)$(BASH) $(srctree)/scripts/$@
2021
2022export_report:
2023	$(PERL) $(srctree)/scripts/export_report.pl
2024
2025PHONY += checkstack kernelrelease kernelversion image_name
2026
2027# UML needs a little special treatment here.  It wants to use the host
2028# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
2029# else wants $(ARCH), including people doing cross-builds, which means
2030# that $(SUBARCH) doesn't work here.
2031ifeq ($(ARCH), um)
2032CHECKSTACK_ARCH := $(SUBARCH)
2033else
2034CHECKSTACK_ARCH := $(ARCH)
2035endif
2036MINSTACKSIZE	?= 100
2037checkstack:
2038	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
2039	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH) $(MINSTACKSIZE)
2040
2041kernelrelease:
2042	@$(filechk_kernel.release)
2043
2044kernelversion:
2045	@echo $(KERNELVERSION)
2046
2047image_name:
2048	@echo $(KBUILD_IMAGE)
2049
2050PHONY += run-command
2051run-command:
2052	$(Q)$(KBUILD_RUN_COMMAND)
2053
2054quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
2055      cmd_rmfiles = rm -rf $(rm-files)
2056
2057# read saved command lines for existing targets
2058existing-targets := $(wildcard $(sort $(targets)))
2059
2060-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
2061
2062endif # config-build
2063endif # mixed-build
2064endif # need-sub-make
2065
2066PHONY += FORCE
2067FORCE:
2068
2069# Declare the contents of the PHONY variable as phony.  We keep that
2070# information in a variable so we can use it in if_changed and friends.
2071.PHONY: $(PHONY)
2072