xref: /linux/Makefile (revision b86406d42ae3c41ae0ce332ea24350829b88af51)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 6
3PATCHLEVEL = 0
4SUBLEVEL = 0
5EXTRAVERSION =
6NAME = Hurr durr I'ma ninja sloth
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 = $(C)
116endif
117ifndef KBUILD_CHECKSRC
118  KBUILD_CHECKSRC = 0
119endif
120
121export KBUILD_CHECKSRC
122
123# Enable "clippy" (a linter) as part of the Rust compilation.
124#
125# Use 'make CLIPPY=1' to enable it.
126ifeq ("$(origin CLIPPY)", "command line")
127  KBUILD_CLIPPY := $(CLIPPY)
128endif
129
130export KBUILD_CLIPPY
131
132# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
133# directory of external module to build. Setting M= takes precedence.
134ifeq ("$(origin M)", "command line")
135  KBUILD_EXTMOD := $(M)
136endif
137
138$(if $(word 2, $(KBUILD_EXTMOD)), \
139	$(error building multiple external modules is not supported))
140
141$(foreach x, % :, $(if $(findstring $x, $(KBUILD_EXTMOD)), \
142	$(error module directory path cannot contain '$x')))
143
144# Remove trailing slashes
145ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
146KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
147endif
148
149export KBUILD_EXTMOD
150
151# Kbuild will save output files in the current working directory.
152# This does not need to match to the root of the kernel source tree.
153#
154# For example, you can do this:
155#
156#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
157#
158# If you want to save output files in a different location, there are
159# two syntaxes to specify it.
160#
161# 1) O=
162# Use "make O=dir/to/store/output/files/"
163#
164# 2) Set KBUILD_OUTPUT
165# Set the environment variable KBUILD_OUTPUT to point to the output directory.
166# export KBUILD_OUTPUT=dir/to/store/output/files/; make
167#
168# The O= assignment takes precedence over the KBUILD_OUTPUT environment
169# variable.
170
171# Do we want to change the working directory?
172ifeq ("$(origin O)", "command line")
173  KBUILD_OUTPUT := $(O)
174endif
175
176ifneq ($(KBUILD_OUTPUT),)
177# Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
178# expand a shell special character '~'. We use a somewhat tedious way here.
179abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
180$(if $(abs_objtree),, \
181     $(error failed to create output directory "$(KBUILD_OUTPUT)"))
182
183# $(realpath ...) resolves symlinks
184abs_objtree := $(realpath $(abs_objtree))
185else
186abs_objtree := $(CURDIR)
187endif # ifneq ($(KBUILD_OUTPUT),)
188
189ifeq ($(abs_objtree),$(CURDIR))
190# Suppress "Entering directory ..." unless we are changing the work directory.
191MAKEFLAGS += --no-print-directory
192else
193need-sub-make := 1
194endif
195
196this-makefile := $(lastword $(MAKEFILE_LIST))
197abs_srctree := $(realpath $(dir $(this-makefile)))
198
199ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
200$(error source directory cannot contain spaces or colons)
201endif
202
203ifneq ($(abs_srctree),$(abs_objtree))
204# Look for make include files relative to root of kernel src
205#
206# --included-dir is added for backward compatibility, but you should not rely on
207# it. Please add $(srctree)/ prefix to include Makefiles in the source tree.
208MAKEFLAGS += --include-dir=$(abs_srctree)
209endif
210
211ifneq ($(filter 3.%,$(MAKE_VERSION)),)
212# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
213# We need to invoke sub-make to avoid implicit rules in the top Makefile.
214need-sub-make := 1
215# Cancel implicit rules for this Makefile.
216$(this-makefile): ;
217endif
218
219export abs_srctree abs_objtree
220export sub_make_done := 1
221
222ifeq ($(need-sub-make),1)
223
224PHONY += $(MAKECMDGOALS) __sub-make
225
226$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
227	@:
228
229# Invoke a second make in the output directory, passing relevant variables
230__sub-make:
231	$(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
232
233endif # need-sub-make
234endif # sub_make_done
235
236# We process the rest of the Makefile if this is the final invocation of make
237ifeq ($(need-sub-make),)
238
239# Do not print "Entering directory ...",
240# but we want to display it when entering to the output directory
241# so that IDEs/editors are able to understand relative filenames.
242MAKEFLAGS += --no-print-directory
243
244ifeq ($(abs_srctree),$(abs_objtree))
245        # building in the source tree
246        srctree := .
247	building_out_of_srctree :=
248else
249        ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
250                # building in a subdirectory of the source tree
251                srctree := ..
252        else
253                srctree := $(abs_srctree)
254        endif
255	building_out_of_srctree := 1
256endif
257
258ifneq ($(KBUILD_ABS_SRCTREE),)
259srctree := $(abs_srctree)
260endif
261
262objtree		:= .
263VPATH		:= $(srctree)
264
265export building_out_of_srctree srctree objtree VPATH
266
267# To make sure we do not include .config for any of the *config targets
268# catch them early, and hand them over to scripts/kconfig/Makefile
269# It is allowed to specify more targets when calling make, including
270# mixing *config targets and build targets.
271# For example 'make oldconfig all'.
272# Detect when mixed targets is specified, and make a second invocation
273# of make so .config is not included in this case either (for *config).
274
275version_h := include/generated/uapi/linux/version.h
276
277clean-targets := %clean mrproper cleandocs
278no-dot-config-targets := $(clean-targets) \
279			 cscope gtags TAGS tags help% %docs check% coccicheck \
280			 $(version_h) headers headers_% archheaders archscripts \
281			 %asm-generic kernelversion %src-pkg dt_binding_check \
282			 outputmakefile rustavailable rustfmt rustfmtcheck
283# Installation targets should not require compiler. Unfortunately, vdso_install
284# is an exception where build artifacts may be updated. This must be fixed.
285no-compiler-targets := $(no-dot-config-targets) install dtbs_install \
286			headers_install modules_install kernelrelease image_name
287no-sync-config-targets := $(no-dot-config-targets) %install kernelrelease \
288			  image_name
289single-targets := %.a %.i %.rsi %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/
290
291config-build	:=
292mixed-build	:=
293need-config	:= 1
294need-compiler	:= 1
295may-sync-config	:= 1
296single-build	:=
297
298ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
299	ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
300		need-config :=
301	endif
302endif
303
304ifneq ($(filter $(no-compiler-targets), $(MAKECMDGOALS)),)
305	ifeq ($(filter-out $(no-compiler-targets), $(MAKECMDGOALS)),)
306		need-compiler :=
307	endif
308endif
309
310ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
311	ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
312		may-sync-config :=
313	endif
314endif
315
316ifneq ($(KBUILD_EXTMOD),)
317	may-sync-config :=
318endif
319
320ifeq ($(KBUILD_EXTMOD),)
321        ifneq ($(filter %config,$(MAKECMDGOALS)),)
322		config-build := 1
323                ifneq ($(words $(MAKECMDGOALS)),1)
324			mixed-build := 1
325                endif
326        endif
327endif
328
329# We cannot build single targets and the others at the same time
330ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
331	single-build := 1
332	ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
333		mixed-build := 1
334	endif
335endif
336
337# For "make -j clean all", "make -j mrproper defconfig all", etc.
338ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
339        ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
340		mixed-build := 1
341        endif
342endif
343
344# install and modules_install need also be processed one by one
345ifneq ($(filter install,$(MAKECMDGOALS)),)
346        ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
347		mixed-build := 1
348        endif
349endif
350
351ifdef mixed-build
352# ===========================================================================
353# We're called with mixed targets (*config and build targets).
354# Handle them one by one.
355
356PHONY += $(MAKECMDGOALS) __build_one_by_one
357
358$(MAKECMDGOALS): __build_one_by_one
359	@:
360
361__build_one_by_one:
362	$(Q)set -e; \
363	for i in $(MAKECMDGOALS); do \
364		$(MAKE) -f $(srctree)/Makefile $$i; \
365	done
366
367else # !mixed-build
368
369include $(srctree)/scripts/Kbuild.include
370
371# Read KERNELRELEASE from include/config/kernel.release (if it exists)
372KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
373KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
374export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
375
376include $(srctree)/scripts/subarch.include
377
378# Cross compiling and selecting different set of gcc/bin-utils
379# ---------------------------------------------------------------------------
380#
381# When performing cross compilation for other architectures ARCH shall be set
382# to the target architecture. (See arch/* for the possibilities).
383# ARCH can be set during invocation of make:
384# make ARCH=ia64
385# Another way is to have ARCH set in the environment.
386# The default ARCH is the host where make is executed.
387
388# CROSS_COMPILE specify the prefix used for all executables used
389# during compilation. Only gcc and related bin-utils executables
390# are prefixed with $(CROSS_COMPILE).
391# CROSS_COMPILE can be set on the command line
392# make CROSS_COMPILE=ia64-linux-
393# Alternatively CROSS_COMPILE can be set in the environment.
394# Default value for CROSS_COMPILE is not to prefix executables
395# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
396ARCH		?= $(SUBARCH)
397
398# Architecture as present in compile.h
399UTS_MACHINE 	:= $(ARCH)
400SRCARCH 	:= $(ARCH)
401
402# Additional ARCH settings for x86
403ifeq ($(ARCH),i386)
404        SRCARCH := x86
405endif
406ifeq ($(ARCH),x86_64)
407        SRCARCH := x86
408endif
409
410# Additional ARCH settings for sparc
411ifeq ($(ARCH),sparc32)
412       SRCARCH := sparc
413endif
414ifeq ($(ARCH),sparc64)
415       SRCARCH := sparc
416endif
417
418# Additional ARCH settings for parisc
419ifeq ($(ARCH),parisc64)
420       SRCARCH := parisc
421endif
422
423export cross_compiling :=
424ifneq ($(SRCARCH),$(SUBARCH))
425cross_compiling := 1
426endif
427
428KCONFIG_CONFIG	?= .config
429export KCONFIG_CONFIG
430
431# SHELL used by kbuild
432CONFIG_SHELL := sh
433
434HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
435HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
436HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
437
438ifneq ($(LLVM),)
439ifneq ($(filter %/,$(LLVM)),)
440LLVM_PREFIX := $(LLVM)
441else ifneq ($(filter -%,$(LLVM)),)
442LLVM_SUFFIX := $(LLVM)
443endif
444
445HOSTCC	= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
446HOSTCXX	= $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
447else
448HOSTCC	= gcc
449HOSTCXX	= g++
450endif
451HOSTRUSTC = rustc
452HOSTPKG_CONFIG	= pkg-config
453
454KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
455			 -O2 -fomit-frame-pointer -std=gnu11 \
456			 -Wdeclaration-after-statement
457KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
458KBUILD_USERLDFLAGS := $(USERLDFLAGS)
459
460# These flags apply to all Rust code in the tree, including the kernel and
461# host programs.
462export rust_common_flags := --edition=2021 \
463			    -Zbinary_dep_depinfo=y \
464			    -Dunsafe_op_in_unsafe_fn -Drust_2018_idioms \
465			    -Dunreachable_pub -Dnon_ascii_idents \
466			    -Wmissing_docs \
467			    -Drustdoc::missing_crate_level_docs \
468			    -Dclippy::correctness -Dclippy::style \
469			    -Dclippy::suspicious -Dclippy::complexity \
470			    -Dclippy::perf \
471			    -Dclippy::let_unit_value -Dclippy::mut_mut \
472			    -Dclippy::needless_bitwise_bool \
473			    -Dclippy::needless_continue \
474			    -Wclippy::dbg_macro
475
476KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
477KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
478KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
479			-Zallow-features= $(HOSTRUSTFLAGS)
480KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
481KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
482
483# Make variables (CC, etc...)
484CPP		= $(CC) -E
485ifneq ($(LLVM),)
486CC		= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
487LD		= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
488AR		= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
489NM		= $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
490OBJCOPY		= $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
491OBJDUMP		= $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
492READELF		= $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
493STRIP		= $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
494else
495CC		= $(CROSS_COMPILE)gcc
496LD		= $(CROSS_COMPILE)ld
497AR		= $(CROSS_COMPILE)ar
498NM		= $(CROSS_COMPILE)nm
499OBJCOPY		= $(CROSS_COMPILE)objcopy
500OBJDUMP		= $(CROSS_COMPILE)objdump
501READELF		= $(CROSS_COMPILE)readelf
502STRIP		= $(CROSS_COMPILE)strip
503endif
504RUSTC		= rustc
505RUSTDOC		= rustdoc
506RUSTFMT		= rustfmt
507CLIPPY_DRIVER	= clippy-driver
508BINDGEN		= bindgen
509CARGO		= cargo
510PAHOLE		= pahole
511RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
512LEX		= flex
513YACC		= bison
514AWK		= awk
515INSTALLKERNEL  := installkernel
516DEPMOD		= depmod
517PERL		= perl
518PYTHON3		= python3
519CHECK		= sparse
520BASH		= bash
521KGZIP		= gzip
522KBZIP2		= bzip2
523KLZOP		= lzop
524LZMA		= lzma
525LZ4		= lz4c
526XZ		= xz
527ZSTD		= zstd
528
529PAHOLE_FLAGS	= $(shell PAHOLE=$(PAHOLE) $(srctree)/scripts/pahole-flags.sh)
530
531CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
532		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
533NOSTDINC_FLAGS :=
534CFLAGS_MODULE   =
535RUSTFLAGS_MODULE =
536AFLAGS_MODULE   =
537LDFLAGS_MODULE  =
538CFLAGS_KERNEL	=
539RUSTFLAGS_KERNEL =
540AFLAGS_KERNEL	=
541LDFLAGS_vmlinux =
542
543# Use USERINCLUDE when you must reference the UAPI directories only.
544USERINCLUDE    := \
545		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
546		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
547		-I$(srctree)/include/uapi \
548		-I$(objtree)/include/generated/uapi \
549                -include $(srctree)/include/linux/compiler-version.h \
550                -include $(srctree)/include/linux/kconfig.h
551
552# Use LINUXINCLUDE when you must reference the include/ directory.
553# Needed to be compatible with the O= option
554LINUXINCLUDE    := \
555		-I$(srctree)/arch/$(SRCARCH)/include \
556		-I$(objtree)/arch/$(SRCARCH)/include/generated \
557		$(if $(building_out_of_srctree),-I$(srctree)/include) \
558		-I$(objtree)/include \
559		$(USERINCLUDE)
560
561KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
562KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
563		   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
564		   -Werror=implicit-function-declaration -Werror=implicit-int \
565		   -Werror=return-type -Wno-format-security \
566		   -std=gnu11
567KBUILD_CPPFLAGS := -D__KERNEL__
568KBUILD_RUSTFLAGS := $(rust_common_flags) \
569		    --target=$(objtree)/rust/target.json \
570		    -Cpanic=abort -Cembed-bitcode=n -Clto=n \
571		    -Cforce-unwind-tables=n -Ccodegen-units=1 \
572		    -Csymbol-mangling-version=v0 \
573		    -Crelocation-model=static \
574		    -Zfunction-sections=n \
575		    -Dclippy::float_arithmetic
576
577KBUILD_AFLAGS_KERNEL :=
578KBUILD_CFLAGS_KERNEL :=
579KBUILD_RUSTFLAGS_KERNEL :=
580KBUILD_AFLAGS_MODULE  := -DMODULE
581KBUILD_CFLAGS_MODULE  := -DMODULE
582KBUILD_RUSTFLAGS_MODULE := --cfg MODULE
583KBUILD_LDFLAGS_MODULE :=
584KBUILD_LDFLAGS :=
585CLANG_FLAGS :=
586
587ifeq ($(KBUILD_CLIPPY),1)
588	RUSTC_OR_CLIPPY_QUIET := CLIPPY
589	RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER)
590else
591	RUSTC_OR_CLIPPY_QUIET := RUSTC
592	RUSTC_OR_CLIPPY = $(RUSTC)
593endif
594
595ifdef RUST_LIB_SRC
596	export RUST_LIB_SRC
597endif
598
599# Allows the usage of unstable features in stable compilers.
600export RUSTC_BOOTSTRAP := 1
601
602export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
603export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN CARGO
604export HOSTRUSTC KBUILD_HOSTRUSTFLAGS
605export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
606export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
607export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
608export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
609export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
610
611export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
612export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
613export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE
614export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
615export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
616export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
617export PAHOLE_FLAGS
618
619# Files to ignore in find ... statements
620
621export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
622			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
623			  -prune -o
624export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
625			 --exclude CVS --exclude .pc --exclude .hg --exclude .git
626
627# ===========================================================================
628# Rules shared between *config targets and build targets
629
630# Basic helpers built in scripts/basic/
631PHONY += scripts_basic
632scripts_basic:
633	$(Q)$(MAKE) $(build)=scripts/basic
634
635PHONY += outputmakefile
636ifdef building_out_of_srctree
637# Before starting out-of-tree build, make sure the source tree is clean.
638# outputmakefile generates a Makefile in the output directory, if using a
639# separate output directory. This allows convenient use of make in the
640# output directory.
641# At the same time when output Makefile generated, generate .gitignore to
642# ignore whole output directory
643
644quiet_cmd_makefile = GEN     Makefile
645      cmd_makefile = { \
646	echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
647	echo "include $(srctree)/Makefile"; \
648	} > Makefile
649
650outputmakefile:
651	$(Q)if [ -f $(srctree)/.config -o \
652		 -d $(srctree)/include/config -o \
653		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
654		echo >&2 "***"; \
655		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
656		echo >&2 "*** in $(abs_srctree)";\
657		echo >&2 "***"; \
658		false; \
659	fi
660	$(Q)ln -fsn $(srctree) source
661	$(call cmd,makefile)
662	$(Q)test -e .gitignore || \
663	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
664endif
665
666# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
667# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
668# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
669# and from include/config/auto.conf.cmd to detect the compiler upgrade.
670CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
671
672ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
673include $(srctree)/scripts/Makefile.clang
674endif
675
676# Include this also for config targets because some architectures need
677# cc-cross-prefix to determine CROSS_COMPILE.
678ifdef need-compiler
679include $(srctree)/scripts/Makefile.compiler
680endif
681
682ifdef config-build
683# ===========================================================================
684# *config targets only - make sure prerequisites are updated, and descend
685# in scripts/kconfig to make the *config target
686
687# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
688# KBUILD_DEFCONFIG may point out an alternative default configuration
689# used for 'make defconfig'
690include $(srctree)/arch/$(SRCARCH)/Makefile
691export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
692
693config: outputmakefile scripts_basic FORCE
694	$(Q)$(MAKE) $(build)=scripts/kconfig $@
695
696%config: outputmakefile scripts_basic FORCE
697	$(Q)$(MAKE) $(build)=scripts/kconfig $@
698
699else #!config-build
700# ===========================================================================
701# Build targets only - this includes vmlinux, arch specific targets, clean
702# targets and others. In general all targets except *config targets.
703
704# If building an external module we do not care about the all: rule
705# but instead __all depend on modules
706PHONY += all
707ifeq ($(KBUILD_EXTMOD),)
708__all: all
709else
710__all: modules
711endif
712
713# Decide whether to build built-in, modular, or both.
714# Normally, just do built-in.
715
716KBUILD_MODULES :=
717KBUILD_BUILTIN := 1
718
719# If we have only "make modules", don't compile built-in objects.
720ifeq ($(MAKECMDGOALS),modules)
721  KBUILD_BUILTIN :=
722endif
723
724# If we have "make <whatever> modules", compile modules
725# in addition to whatever we do anyway.
726# Just "make" or "make all" shall build modules as well
727
728ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
729  KBUILD_MODULES := 1
730endif
731
732ifeq ($(MAKECMDGOALS),)
733  KBUILD_MODULES := 1
734endif
735
736export KBUILD_MODULES KBUILD_BUILTIN
737
738ifdef need-config
739include include/config/auto.conf
740endif
741
742ifeq ($(KBUILD_EXTMOD),)
743# Objects we will link into vmlinux / subdirs we need to visit
744core-y		:= init/ usr/ arch/$(SRCARCH)/
745drivers-y	:= drivers/ sound/
746drivers-$(CONFIG_SAMPLES) += samples/
747drivers-$(CONFIG_NET) += net/
748drivers-y	+= virt/
749libs-y		:= lib/
750endif # KBUILD_EXTMOD
751
752# The all: target is the default when no target is given on the
753# command line.
754# This allow a user to issue only 'make' to build a kernel including modules
755# Defaults to vmlinux, but the arch makefile usually adds further targets
756all: vmlinux
757
758CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
759ifdef CONFIG_CC_IS_GCC
760CFLAGS_GCOV	+= -fno-tree-loop-im
761endif
762export CFLAGS_GCOV
763
764# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
765ifdef CONFIG_FUNCTION_TRACER
766  CC_FLAGS_FTRACE := -pg
767endif
768
769include $(srctree)/arch/$(SRCARCH)/Makefile
770
771ifdef need-config
772ifdef may-sync-config
773# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
774# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
775# because some architectures define CROSS_COMPILE there.
776include include/config/auto.conf.cmd
777
778$(KCONFIG_CONFIG):
779	@echo >&2 '***'
780	@echo >&2 '*** Configuration file "$@" not found!'
781	@echo >&2 '***'
782	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
783	@echo >&2 '*** "make menuconfig" or "make xconfig").'
784	@echo >&2 '***'
785	@/bin/false
786
787# The actual configuration files used during the build are stored in
788# include/generated/ and include/config/. Update them if .config is newer than
789# include/config/auto.conf (which mirrors .config).
790#
791# This exploits the 'multi-target pattern rule' trick.
792# The syncconfig should be executed only once to make all the targets.
793# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
794#
795# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
796# so you cannot notice that Kconfig is waiting for the user input.
797%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
798	$(Q)$(kecho) "  SYNC    $@"
799	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
800else # !may-sync-config
801# External modules and some install targets need include/generated/autoconf.h
802# and include/config/auto.conf but do not care if they are up-to-date.
803# Use auto.conf to trigger the test
804PHONY += include/config/auto.conf
805
806include/config/auto.conf:
807	$(Q)test -e include/generated/autoconf.h -a -e $@ || (		\
808	echo >&2;							\
809	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
810	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
811	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
812	echo >&2 ;							\
813	/bin/false)
814
815endif # may-sync-config
816endif # need-config
817
818KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
819KBUILD_CFLAGS	+= $(call cc-disable-warning,frame-address,)
820KBUILD_CFLAGS	+= $(call cc-disable-warning, format-truncation)
821KBUILD_CFLAGS	+= $(call cc-disable-warning, format-overflow)
822KBUILD_CFLAGS	+= $(call cc-disable-warning, address-of-packed-member)
823
824ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
825KBUILD_CFLAGS += -O2
826KBUILD_RUSTFLAGS += -Copt-level=2
827else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
828KBUILD_CFLAGS += -Os
829KBUILD_RUSTFLAGS += -Copt-level=s
830endif
831
832# Always set `debug-assertions` and `overflow-checks` because their default
833# depends on `opt-level` and `debug-assertions`, respectively.
834KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
835KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
836
837# Tell gcc to never replace conditional load with a non-conditional one
838ifdef CONFIG_CC_IS_GCC
839# gcc-10 renamed --param=allow-store-data-races=0 to
840# -fno-allow-store-data-races.
841KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
842KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
843endif
844
845ifdef CONFIG_READABLE_ASM
846# Disable optimizations that make assembler listings hard to read.
847# reorder blocks reorders the control in the function
848# ipa clone creates specialized cloned functions
849# partial inlining inlines only parts of functions
850KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
851endif
852
853ifneq ($(CONFIG_FRAME_WARN),0)
854KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
855endif
856
857stackp-flags-y                                    := -fno-stack-protector
858stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
859stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
860
861KBUILD_CFLAGS += $(stackp-flags-y)
862
863KBUILD_CFLAGS-$(CONFIG_WERROR) += -Werror
864KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds
865KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
866
867KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings
868KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y)
869
870ifdef CONFIG_CC_IS_CLANG
871KBUILD_CPPFLAGS += -Qunused-arguments
872# The kernel builds with '-std=gnu11' so use of GNU extensions is acceptable.
873KBUILD_CFLAGS += -Wno-gnu
874else
875
876# gcc inanely warns about local variables called 'main'
877KBUILD_CFLAGS += -Wno-main
878endif
879
880# These warnings generated too much noise in a regular build.
881# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
882KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
883KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
884
885# These result in bogus false positives
886KBUILD_CFLAGS += $(call cc-disable-warning, dangling-pointer)
887
888ifdef CONFIG_FRAME_POINTER
889KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
890KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y
891else
892# Some targets (ARM with Thumb2, for example), can't be built with frame
893# pointers.  For those, we don't have FUNCTION_TRACER automatically
894# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
895# incompatible with -fomit-frame-pointer with current GCC, so we don't use
896# -fomit-frame-pointer with FUNCTION_TRACER.
897# In the Rust target specification, "frame-pointer" is set explicitly
898# to "may-omit".
899ifndef CONFIG_FUNCTION_TRACER
900KBUILD_CFLAGS	+= -fomit-frame-pointer
901endif
902endif
903
904# Initialize all stack variables with a 0xAA pattern.
905ifdef CONFIG_INIT_STACK_ALL_PATTERN
906KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
907endif
908
909# Initialize all stack variables with a zero value.
910ifdef CONFIG_INIT_STACK_ALL_ZERO
911KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
912ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
913# https://github.com/llvm/llvm-project/issues/44842
914KBUILD_CFLAGS	+= -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
915endif
916endif
917
918# While VLAs have been removed, GCC produces unreachable stack probes
919# for the randomize_kstack_offset feature. Disable it for all compilers.
920KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
921
922# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
923ifdef CONFIG_ZERO_CALL_USED_REGS
924KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
925endif
926
927ifdef CONFIG_FUNCTION_TRACER
928ifdef CONFIG_FTRACE_MCOUNT_USE_CC
929  CC_FLAGS_FTRACE	+= -mrecord-mcount
930  ifdef CONFIG_HAVE_NOP_MCOUNT
931    ifeq ($(call cc-option-yn, -mnop-mcount),y)
932      CC_FLAGS_FTRACE	+= -mnop-mcount
933      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
934    endif
935  endif
936endif
937ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
938  CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
939endif
940ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
941  ifdef CONFIG_HAVE_C_RECORDMCOUNT
942    BUILD_C_RECORDMCOUNT := y
943    export BUILD_C_RECORDMCOUNT
944  endif
945endif
946ifdef CONFIG_HAVE_FENTRY
947  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
948  ifeq ($(call cc-option-yn, -mfentry),y)
949    CC_FLAGS_FTRACE	+= -mfentry
950    CC_FLAGS_USING	+= -DCC_USING_FENTRY
951  endif
952endif
953export CC_FLAGS_FTRACE
954KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
955KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
956endif
957
958# We trigger additional mismatches with less inlining
959ifdef CONFIG_DEBUG_SECTION_MISMATCH
960KBUILD_CFLAGS += -fno-inline-functions-called-once
961endif
962
963# `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
964ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
965KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
966KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
967LDFLAGS_vmlinux += --gc-sections
968endif
969
970ifdef CONFIG_SHADOW_CALL_STACK
971CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
972KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
973export CC_FLAGS_SCS
974endif
975
976ifdef CONFIG_LTO_CLANG
977ifdef CONFIG_LTO_CLANG_THIN
978CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
979KBUILD_LDFLAGS	+= --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
980else
981CC_FLAGS_LTO	:= -flto
982endif
983CC_FLAGS_LTO	+= -fvisibility=hidden
984
985# Limit inlining across translation units to reduce binary size
986KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
987
988# Check for frame size exceeding threshold during prolog/epilog insertion
989# when using lld < 13.0.0.
990ifneq ($(CONFIG_FRAME_WARN),0)
991ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
992KBUILD_LDFLAGS	+= -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
993endif
994endif
995endif
996
997ifdef CONFIG_LTO
998KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
999KBUILD_AFLAGS	+= -fno-lto
1000export CC_FLAGS_LTO
1001endif
1002
1003ifdef CONFIG_CFI_CLANG
1004CC_FLAGS_CFI	:= -fsanitize=kcfi
1005KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
1006export CC_FLAGS_CFI
1007endif
1008
1009ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B
1010KBUILD_CFLAGS += -falign-functions=64
1011endif
1012
1013# arch Makefile may override CC so keep this after arch Makefile is included
1014NOSTDINC_FLAGS += -nostdinc
1015
1016# warn about C99 declaration after statement
1017KBUILD_CFLAGS += -Wdeclaration-after-statement
1018
1019# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
1020KBUILD_CFLAGS += -Wvla
1021
1022# disable pointer signed / unsigned warnings in gcc 4.0
1023KBUILD_CFLAGS += -Wno-pointer-sign
1024
1025# In order to make sure new function cast mismatches are not introduced
1026# in the kernel (to avoid tripping CFI checking), the kernel should be
1027# globally built with -Wcast-function-type.
1028KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type)
1029
1030# disable stringop warnings in gcc 8+
1031KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
1032
1033# We'll want to enable this eventually, but it's not going away for 5.7 at least
1034KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
1035
1036# Another good warning that we'll want to enable eventually
1037KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
1038
1039# Enabled with W=2, disabled by default as noisy
1040ifdef CONFIG_CC_IS_GCC
1041KBUILD_CFLAGS += -Wno-maybe-uninitialized
1042endif
1043
1044ifdef CONFIG_CC_IS_GCC
1045# The allocators already balk at large sizes, so silence the compiler
1046# warnings for bounds checks involving those possible values. While
1047# -Wno-alloc-size-larger-than would normally be used here, earlier versions
1048# of gcc (<9.1) weirdly don't handle the option correctly when _other_
1049# warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX
1050# doesn't work (as it is documented to), silently resolving to "0" prior to
1051# version 9.1 (and producing an error more recently). Numeric values larger
1052# than PTRDIFF_MAX also don't work prior to version 9.1, which are silently
1053# ignored, continuing to default to PTRDIFF_MAX. So, left with no other
1054# choice, we must perform a versioned check to disable this warning.
1055# https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au
1056KBUILD_CFLAGS += $(call cc-ifversion, -ge, 0901, -Wno-alloc-size-larger-than)
1057endif
1058
1059# disable invalid "can't wrap" optimizations for signed / pointers
1060KBUILD_CFLAGS	+= -fno-strict-overflow
1061
1062# Make sure -fstack-check isn't enabled (like gentoo apparently did)
1063KBUILD_CFLAGS  += -fno-stack-check
1064
1065# conserve stack if available
1066ifdef CONFIG_CC_IS_GCC
1067KBUILD_CFLAGS   += -fconserve-stack
1068endif
1069
1070# Prohibit date/time macros, which would make the build non-deterministic
1071KBUILD_CFLAGS   += -Werror=date-time
1072
1073# enforce correct pointer usage
1074KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
1075
1076# Require designated initializers for all marked structures
1077KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
1078
1079# change __FILE__ to the relative path from the srctree
1080KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1081
1082# include additional Makefiles when needed
1083include-y			:= scripts/Makefile.extrawarn
1084include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
1085include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1086include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1087include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1088include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1089include-$(CONFIG_RANDSTRUCT)	+= scripts/Makefile.randstruct
1090include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1091
1092include $(addprefix $(srctree)/, $(include-y))
1093
1094# scripts/Makefile.gcc-plugins is intentionally included last.
1095# Do not add $(call cc-option,...) below this line. When you build the kernel
1096# from the clean source tree, the GCC plugins do not exist at this point.
1097
1098# Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
1099KBUILD_CPPFLAGS += $(KCPPFLAGS)
1100KBUILD_AFLAGS   += $(KAFLAGS)
1101KBUILD_CFLAGS   += $(KCFLAGS)
1102KBUILD_RUSTFLAGS += $(KRUSTFLAGS)
1103
1104KBUILD_LDFLAGS_MODULE += --build-id=sha1
1105LDFLAGS_vmlinux += --build-id=sha1
1106
1107KBUILD_LDFLAGS	+= -z noexecstack
1108ifeq ($(CONFIG_LD_IS_BFD),y)
1109KBUILD_LDFLAGS	+= $(call ld-option,--no-warn-rwx-segments)
1110endif
1111
1112ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1113LDFLAGS_vmlinux	+= $(call ld-option, -X,)
1114endif
1115
1116ifeq ($(CONFIG_RELR),y)
1117LDFLAGS_vmlinux	+= --pack-dyn-relocs=relr --use-android-relr-tags
1118endif
1119
1120# We never want expected sections to be placed heuristically by the
1121# linker. All sections should be explicitly named in the linker script.
1122ifdef CONFIG_LD_ORPHAN_WARN
1123LDFLAGS_vmlinux += --orphan-handling=warn
1124endif
1125
1126# Align the bit size of userspace programs with the kernel
1127KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1128KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1129
1130# make the checker run with the right architecture
1131CHECKFLAGS += --arch=$(ARCH)
1132
1133# insure the checker run with the right endianness
1134CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1135
1136# the checker needs the correct machine size
1137CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1138
1139# Default kernel image to build when no specific target is given.
1140# KBUILD_IMAGE may be overruled on the command line or
1141# set in the environment
1142# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1143# this default value
1144export KBUILD_IMAGE ?= vmlinux
1145
1146#
1147# INSTALL_PATH specifies where to place the updated kernel and system map
1148# images. Default is /boot, but you can set it to other values
1149export	INSTALL_PATH ?= /boot
1150
1151#
1152# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1153# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1154# an argument if needed. Otherwise it defaults to the kernel install path
1155#
1156export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1157
1158#
1159# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1160# relocations required by build roots.  This is not defined in the
1161# makefile but the argument can be passed to make if needed.
1162#
1163
1164MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1165export MODLIB
1166
1167PHONY += prepare0
1168
1169export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1170export MODORDER := $(extmod_prefix)modules.order
1171export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1172
1173ifeq ($(KBUILD_EXTMOD),)
1174core-y			+= kernel/ certs/ mm/ fs/ ipc/ security/ crypto/
1175core-$(CONFIG_BLOCK)	+= block/
1176core-$(CONFIG_IO_URING)	+= io_uring/
1177core-$(CONFIG_RUST)	+= rust/
1178
1179vmlinux-dirs	:= $(patsubst %/,%,$(filter %/, \
1180		     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1181		     $(libs-y) $(libs-m)))
1182
1183vmlinux-alldirs	:= $(sort $(vmlinux-dirs) Documentation \
1184		     $(patsubst %/,%,$(filter %/, $(core-) \
1185			$(drivers-) $(libs-))))
1186
1187build-dirs	:= $(vmlinux-dirs)
1188clean-dirs	:= $(vmlinux-alldirs)
1189
1190subdir-modorder := $(addsuffix /modules.order, $(build-dirs))
1191
1192# Externally visible symbols (used by link-vmlinux.sh)
1193KBUILD_VMLINUX_OBJS := $(head-y) $(patsubst %/,%/built-in.a, $(core-y))
1194KBUILD_VMLINUX_OBJS += $(addsuffix built-in.a, $(filter %/, $(libs-y)))
1195ifdef CONFIG_MODULES
1196KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1197KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1198else
1199KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1200endif
1201KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y))
1202
1203export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
1204export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1205# used by scripts/Makefile.package
1206export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1207
1208vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1209
1210# Recurse until adjust_autoksyms.sh is satisfied
1211PHONY += autoksyms_recursive
1212ifdef CONFIG_TRIM_UNUSED_KSYMS
1213# For the kernel to actually contain only the needed exported symbols,
1214# we have to build modules as well to determine what those symbols are.
1215# (this can be evaluated only once include/config/auto.conf has been included)
1216KBUILD_MODULES := 1
1217
1218autoksyms_recursive: descend modules.order
1219	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1220	  "$(MAKE) -f $(srctree)/Makefile autoksyms_recursive"
1221endif
1222
1223autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1224
1225quiet_cmd_autoksyms_h = GEN     $@
1226      cmd_autoksyms_h = mkdir -p $(dir $@); \
1227			$(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1228
1229$(autoksyms_h):
1230	$(call cmd,autoksyms_h)
1231
1232ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1233
1234# Final link of vmlinux with optional arch pass after final link
1235cmd_link-vmlinux =                                                 \
1236	$(CONFIG_SHELL) $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)";    \
1237	$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1238
1239vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1240	+$(call if_changed_dep,link-vmlinux)
1241
1242targets := vmlinux
1243
1244# The actual objects are generated when descending,
1245# make sure no implicit rule kicks in
1246$(sort $(vmlinux-deps) $(subdir-modorder)): descend ;
1247
1248filechk_kernel.release = \
1249	echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1250
1251# Store (new) KERNELRELEASE string in include/config/kernel.release
1252include/config/kernel.release: FORCE
1253	$(call filechk,kernel.release)
1254
1255# Additional helpers built in scripts/
1256# Carefully list dependencies so we do not try to build scripts twice
1257# in parallel
1258PHONY += scripts
1259scripts: scripts_basic scripts_dtc
1260	$(Q)$(MAKE) $(build)=$(@)
1261
1262# Things we need to do before we recursively start building the kernel
1263# or the modules are listed in "prepare".
1264# A multi level approach is used. prepareN is processed before prepareN-1.
1265# archprepare is used in arch Makefiles and when processed asm symlink,
1266# version.h and scripts_basic is processed / created.
1267
1268PHONY += prepare archprepare
1269
1270archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1271	asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1272	include/generated/autoconf.h remove-stale-files
1273
1274prepare0: archprepare
1275	$(Q)$(MAKE) $(build)=scripts/mod
1276	$(Q)$(MAKE) $(build)=.
1277
1278# All the preparing..
1279prepare: prepare0
1280ifdef CONFIG_RUST
1281	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh -v
1282	$(Q)$(MAKE) $(build)=rust
1283endif
1284
1285PHONY += remove-stale-files
1286remove-stale-files:
1287	$(Q)$(srctree)/scripts/remove-stale-files
1288
1289# Support for using generic headers in asm-generic
1290asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1291
1292PHONY += asm-generic uapi-asm-generic
1293asm-generic: uapi-asm-generic
1294	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1295	generic=include/asm-generic
1296uapi-asm-generic:
1297	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1298	generic=include/uapi/asm-generic
1299
1300# Generate some files
1301# ---------------------------------------------------------------------------
1302
1303# KERNELRELEASE can change from a few different places, meaning version.h
1304# needs to be updated, so this check is forced on all builds
1305
1306uts_len := 64
1307define filechk_utsrelease.h
1308	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1309	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1310	  exit 1;                                                         \
1311	fi;                                                               \
1312	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1313endef
1314
1315define filechk_version.h
1316	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1317		echo \#define LINUX_VERSION_CODE $(shell                 \
1318		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1319	else                                                             \
1320		echo \#define LINUX_VERSION_CODE $(shell                 \
1321		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1322	fi;                                                              \
1323	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1324	((c) > 255 ? 255 : (c)))';                                       \
1325	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1326	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1327	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1328endef
1329
1330$(version_h): PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1331$(version_h): SUBLEVEL := $(or $(SUBLEVEL), 0)
1332$(version_h): FORCE
1333	$(call filechk,version.h)
1334
1335include/generated/utsrelease.h: include/config/kernel.release FORCE
1336	$(call filechk,utsrelease.h)
1337
1338PHONY += headerdep
1339headerdep:
1340	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1341	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1342
1343# ---------------------------------------------------------------------------
1344# Kernel headers
1345
1346#Default location for installed headers
1347export INSTALL_HDR_PATH = $(objtree)/usr
1348
1349quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1350      cmd_headers_install = \
1351	mkdir -p $(INSTALL_HDR_PATH); \
1352	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1353	usr/include $(INSTALL_HDR_PATH)
1354
1355PHONY += headers_install
1356headers_install: headers
1357	$(call cmd,headers_install)
1358
1359PHONY += archheaders archscripts
1360
1361hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1362
1363PHONY += headers
1364headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1365	$(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML))
1366	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1367	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1368
1369ifdef CONFIG_HEADERS_INSTALL
1370prepare: headers
1371endif
1372
1373PHONY += scripts_unifdef
1374scripts_unifdef: scripts_basic
1375	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1376
1377# ---------------------------------------------------------------------------
1378# Install
1379
1380# Many distributions have the custom install script, /sbin/installkernel.
1381# If DKMS is installed, 'make install' will eventually recurse back
1382# to this Makefile to build and install external modules.
1383# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1384
1385quiet_cmd_install = INSTALL $(INSTALL_PATH)
1386      cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1387
1388# ---------------------------------------------------------------------------
1389# Tools
1390
1391ifdef CONFIG_OBJTOOL
1392prepare: tools/objtool
1393endif
1394
1395ifdef CONFIG_BPF
1396ifdef CONFIG_DEBUG_INFO_BTF
1397prepare: tools/bpf/resolve_btfids
1398endif
1399endif
1400
1401PHONY += resolve_btfids_clean
1402
1403resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1404
1405# tools/bpf/resolve_btfids directory might not exist
1406# in output directory, skip its clean in that case
1407resolve_btfids_clean:
1408ifneq ($(wildcard $(resolve_btfids_O)),)
1409	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1410endif
1411
1412# Clear a bunch of variables before executing the submake
1413ifeq ($(quiet),silent_)
1414tools_silent=s
1415endif
1416
1417tools/: FORCE
1418	$(Q)mkdir -p $(objtree)/tools
1419	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1420
1421tools/%: FORCE
1422	$(Q)mkdir -p $(objtree)/tools
1423	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1424
1425# ---------------------------------------------------------------------------
1426# Kernel selftest
1427
1428PHONY += kselftest
1429kselftest: headers
1430	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1431
1432kselftest-%: headers FORCE
1433	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1434
1435PHONY += kselftest-merge
1436kselftest-merge:
1437	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1438	$(Q)find $(srctree)/tools/testing/selftests -name config | \
1439		xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1440	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1441
1442# ---------------------------------------------------------------------------
1443# Devicetree files
1444
1445ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1446dtstree := arch/$(SRCARCH)/boot/dts
1447endif
1448
1449ifneq ($(dtstree),)
1450
1451%.dtb: dtbs_prepare
1452	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1453
1454%.dtbo: dtbs_prepare
1455	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1456
1457PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1458dtbs: dtbs_prepare
1459	$(Q)$(MAKE) $(build)=$(dtstree)
1460
1461# include/config/kernel.release is actually needed when installing DTBs because
1462# INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1463# dtbs_install depend on it as dtbs_install may run as root.
1464dtbs_prepare: include/config/kernel.release scripts_dtc
1465
1466ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1467export CHECK_DTBS=y
1468dtbs: dt_binding_check
1469endif
1470
1471dtbs_check: dtbs
1472
1473dtbs_install:
1474	$(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1475
1476ifdef CONFIG_OF_EARLY_FLATTREE
1477all: dtbs
1478endif
1479
1480endif
1481
1482PHONY += scripts_dtc
1483scripts_dtc: scripts_basic
1484	$(Q)$(MAKE) $(build)=scripts/dtc
1485
1486ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1487export CHECK_DT_BINDING=y
1488endif
1489
1490PHONY += dt_binding_check
1491dt_binding_check: scripts_dtc
1492	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1493
1494# ---------------------------------------------------------------------------
1495# Modules
1496
1497ifdef CONFIG_MODULES
1498
1499# By default, build modules as well
1500
1501all: modules
1502
1503# When we're building modules with modversions, we need to consider
1504# the built-in objects during the descend as well, in order to
1505# make sure the checksums are up to date before we record them.
1506ifdef CONFIG_MODVERSIONS
1507  KBUILD_BUILTIN := 1
1508endif
1509
1510# Build modules
1511#
1512# A module can be listed more than once in obj-m resulting in
1513# duplicate lines in modules.order files.  Those are removed
1514# using awk while concatenating to the final file.
1515
1516PHONY += modules
1517modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
1518
1519cmd_modules_order = $(AWK) '!x[$$0]++' $(real-prereqs) > $@
1520
1521modules.order: $(subdir-modorder) FORCE
1522	$(call if_changed,modules_order)
1523
1524targets += modules.order
1525
1526# Target to prepare building external modules
1527PHONY += modules_prepare
1528modules_prepare: prepare
1529	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1530
1531export modules_sign_only :=
1532
1533ifeq ($(CONFIG_MODULE_SIG),y)
1534PHONY += modules_sign
1535modules_sign: modules_install
1536	@:
1537
1538# modules_sign is a subset of modules_install.
1539# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1540ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
1541modules_sign_only := y
1542endif
1543endif
1544
1545modinst_pre :=
1546ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
1547modinst_pre := __modinst_pre
1548endif
1549
1550modules_install: $(modinst_pre)
1551PHONY += __modinst_pre
1552__modinst_pre:
1553	@rm -rf $(MODLIB)/kernel
1554	@rm -f $(MODLIB)/source
1555	@mkdir -p $(MODLIB)/kernel
1556	@ln -s $(abspath $(srctree)) $(MODLIB)/source
1557	@if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1558		rm -f $(MODLIB)/build ; \
1559		ln -s $(CURDIR) $(MODLIB)/build ; \
1560	fi
1561	@sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1562	@cp -f modules.builtin $(MODLIB)/
1563	@cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1564
1565endif # CONFIG_MODULES
1566
1567###
1568# Cleaning is done on three levels.
1569# make clean     Delete most generated files
1570#                Leave enough to build external modules
1571# make mrproper  Delete the current configuration, and all generated files
1572# make distclean Remove editor backup files, patch leftover files and the like
1573
1574# Directories & files removed with 'make clean'
1575CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1576	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1577	       compile_commands.json .thinlto-cache rust/test rust/doc
1578
1579# Directories & files removed with 'make mrproper'
1580MRPROPER_FILES += include/config include/generated          \
1581		  arch/$(SRCARCH)/include/generated .objdiff \
1582		  debian snap tar-install \
1583		  .config .config.old .version \
1584		  Module.symvers \
1585		  certs/signing_key.pem \
1586		  certs/x509.genkey \
1587		  vmlinux-gdb.py \
1588		  *.spec \
1589		  rust/target.json rust/libmacros.so
1590
1591# clean - Delete most, but leave enough to build external modules
1592#
1593clean: rm-files := $(CLEAN_FILES)
1594
1595PHONY += archclean vmlinuxclean
1596
1597vmlinuxclean:
1598	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1599	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1600
1601clean: archclean vmlinuxclean resolve_btfids_clean
1602
1603# mrproper - Delete all generated files, including .config
1604#
1605mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1606mrproper-dirs      := $(addprefix _mrproper_,scripts)
1607
1608PHONY += $(mrproper-dirs) mrproper
1609$(mrproper-dirs):
1610	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1611
1612mrproper: clean $(mrproper-dirs)
1613	$(call cmd,rmfiles)
1614	@find . $(RCS_FIND_IGNORE) \
1615		\( -name '*.rmeta' \) \
1616		-type f -print | xargs rm -f
1617
1618# distclean
1619#
1620PHONY += distclean
1621
1622distclean: mrproper
1623	@find . $(RCS_FIND_IGNORE) \
1624		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1625		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1626		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1627		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1628		-type f -print | xargs rm -f
1629
1630
1631# Packaging of the kernel to various formats
1632# ---------------------------------------------------------------------------
1633
1634%src-pkg: FORCE
1635	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1636%pkg: include/config/kernel.release FORCE
1637	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1638
1639# Brief documentation of the typical targets used
1640# ---------------------------------------------------------------------------
1641
1642boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1643boards := $(sort $(notdir $(boards)))
1644board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1645board-dirs := $(sort $(notdir $(board-dirs:/=)))
1646
1647PHONY += help
1648help:
1649	@echo  'Cleaning targets:'
1650	@echo  '  clean		  - Remove most generated files but keep the config and'
1651	@echo  '                    enough build support to build external modules'
1652	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1653	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1654	@echo  ''
1655	@echo  'Configuration targets:'
1656	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1657	@echo  ''
1658	@echo  'Other generic targets:'
1659	@echo  '  all		  - Build all targets marked with [*]'
1660	@echo  '* vmlinux	  - Build the bare kernel'
1661	@echo  '* modules	  - Build all modules'
1662	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1663	@echo  '  dir/            - Build all files in dir and below'
1664	@echo  '  dir/file.[ois]  - Build specified target only'
1665	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1666	@echo  '                    (requires compiler support for LLVM assembly generation)'
1667	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1668	@echo  '                    (requires a recent binutils and recent build (System.map))'
1669	@echo  '  dir/file.ko     - Build module including final link'
1670	@echo  '  modules_prepare - Set up for building external modules'
1671	@echo  '  tags/TAGS	  - Generate tags file for editors'
1672	@echo  '  cscope	  - Generate cscope index'
1673	@echo  '  gtags           - Generate GNU GLOBAL index'
1674	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1675	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1676	@echo  '  image_name	  - Output the image name (use with make -s)'
1677	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1678	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1679	 echo  ''
1680	@echo  'Static analysers:'
1681	@echo  '  checkstack      - Generate a list of stack hogs'
1682	@echo  '  versioncheck    - Sanity check on version.h usage'
1683	@echo  '  includecheck    - Check for duplicate included header files'
1684	@echo  '  export_report   - List the usages of all exported symbols'
1685	@echo  '  headerdep       - Detect inclusion cycles in headers'
1686	@echo  '  coccicheck      - Check with Coccinelle'
1687	@echo  '  clang-analyzer  - Check with clang static analyzer'
1688	@echo  '  clang-tidy      - Check with clang-tidy'
1689	@echo  ''
1690	@echo  'Tools:'
1691	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1692	@echo  ''
1693	@echo  'Kernel selftest:'
1694	@echo  '  kselftest         - Build and run kernel selftest'
1695	@echo  '                      Build, install, and boot kernel before'
1696	@echo  '                      running kselftest on it'
1697	@echo  '                      Run as root for full coverage'
1698	@echo  '  kselftest-all     - Build kernel selftest'
1699	@echo  '  kselftest-install - Build and install kernel selftest'
1700	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1701	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1702	@echo  '		      kselftest to existing .config.'
1703	@echo  ''
1704	@echo  'Rust targets:'
1705	@echo  '  rustavailable   - Checks whether the Rust toolchain is'
1706	@echo  '		    available and, if not, explains why.'
1707	@echo  '  rustfmt	  - Reformat all the Rust code in the kernel'
1708	@echo  '  rustfmtcheck	  - Checks if all the Rust code in the kernel'
1709	@echo  '		    is formatted, printing a diff otherwise.'
1710	@echo  '  rustdoc	  - Generate Rust documentation'
1711	@echo  '		    (requires kernel .config)'
1712	@echo  '  rusttest        - Runs the Rust tests'
1713	@echo  '                    (requires kernel .config; downloads external repos)'
1714	@echo  '  rust-analyzer	  - Generate rust-project.json rust-analyzer support file'
1715	@echo  '		    (requires kernel .config)'
1716	@echo  '  dir/file.[os]   - Build specified target only'
1717	@echo  '  dir/file.rsi    - Build macro expanded source, similar to C preprocessing.'
1718	@echo  '                    Run with RUSTFMT=n to skip reformatting if needed.'
1719	@echo  '                    The output is not intended to be compilable.'
1720	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1721	@echo  ''
1722	@$(if $(dtstree), \
1723		echo 'Devicetree:'; \
1724		echo '* dtbs             - Build device tree blobs for enabled boards'; \
1725		echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1726		echo '  dt_binding_check - Validate device tree binding documents'; \
1727		echo '  dtbs_check       - Validate device tree source files';\
1728		echo '')
1729
1730	@echo 'Userspace tools targets:'
1731	@echo '  use "make tools/help"'
1732	@echo '  or  "cd tools; make help"'
1733	@echo  ''
1734	@echo  'Kernel packaging:'
1735	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1736	@echo  ''
1737	@echo  'Documentation targets:'
1738	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1739	@echo  ''
1740	@echo  'Architecture specific targets ($(SRCARCH)):'
1741	@$(or $(archhelp),\
1742		echo '  No architecture specific help defined for $(SRCARCH)')
1743	@echo  ''
1744	@$(if $(boards), \
1745		$(foreach b, $(boards), \
1746		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1747		echo '')
1748	@$(if $(board-dirs), \
1749		$(foreach b, $(board-dirs), \
1750		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1751		printf "  %-16s - Show all of the above\\n" help-boards; \
1752		echo '')
1753
1754	@echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1755	@echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1756	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1757	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1758	@echo  '                       (sparse by default)'
1759	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1760	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1761	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1762	@echo  '		1: warnings which may be relevant and do not occur too often'
1763	@echo  '		2: warnings which occur quite often but may still be relevant'
1764	@echo  '		3: more obscure warnings, can most likely be ignored'
1765	@echo  '		e: warnings are being treated as errors'
1766	@echo  '		Multiple levels can be combined with W=12 or W=123'
1767	@echo  ''
1768	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1769	@echo  'For further info see the ./README file'
1770
1771
1772help-board-dirs := $(addprefix help-,$(board-dirs))
1773
1774help-boards: $(help-board-dirs)
1775
1776boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1777
1778$(help-board-dirs): help-%:
1779	@echo  'Architecture specific targets ($(SRCARCH) $*):'
1780	@$(if $(boards-per-dir), \
1781		$(foreach b, $(boards-per-dir), \
1782		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1783		echo '')
1784
1785
1786# Documentation targets
1787# ---------------------------------------------------------------------------
1788DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1789	       linkcheckdocs dochelp refcheckdocs
1790PHONY += $(DOC_TARGETS)
1791$(DOC_TARGETS):
1792	$(Q)$(MAKE) $(build)=Documentation $@
1793
1794
1795# Rust targets
1796# ---------------------------------------------------------------------------
1797
1798# "Is Rust available?" target
1799PHONY += rustavailable
1800rustavailable:
1801	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh -v && echo "Rust is available!"
1802
1803# Documentation target
1804#
1805# Using the singular to avoid running afoul of `no-dot-config-targets`.
1806PHONY += rustdoc
1807rustdoc: prepare
1808	$(Q)$(MAKE) $(build)=rust $@
1809
1810# Testing target
1811PHONY += rusttest
1812rusttest: prepare
1813	$(Q)$(MAKE) $(build)=rust $@
1814
1815# Formatting targets
1816PHONY += rustfmt rustfmtcheck
1817
1818# We skip `rust/alloc` since we want to minimize the diff w.r.t. upstream.
1819#
1820# We match using absolute paths since `find` does not resolve them
1821# when matching, which is a problem when e.g. `srctree` is `..`.
1822# We `grep` afterwards in order to remove the directory entry itself.
1823rustfmt:
1824	$(Q)find $(abs_srctree) -type f -name '*.rs' \
1825		-o -path $(abs_srctree)/rust/alloc -prune \
1826		-o -path $(abs_objtree)/rust/test -prune \
1827		| grep -Fv $(abs_srctree)/rust/alloc \
1828		| grep -Fv $(abs_objtree)/rust/test \
1829		| grep -Fv generated \
1830		| xargs $(RUSTFMT) $(rustfmt_flags)
1831
1832rustfmtcheck: rustfmt_flags = --check
1833rustfmtcheck: rustfmt
1834
1835# IDE support targets
1836PHONY += rust-analyzer
1837rust-analyzer:
1838	$(Q)$(MAKE) $(build)=rust $@
1839
1840# Misc
1841# ---------------------------------------------------------------------------
1842
1843PHONY += scripts_gdb
1844scripts_gdb: prepare0
1845	$(Q)$(MAKE) $(build)=scripts/gdb
1846	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1847
1848ifdef CONFIG_GDB_SCRIPTS
1849all: scripts_gdb
1850endif
1851
1852else # KBUILD_EXTMOD
1853
1854###
1855# External module support.
1856# When building external modules the kernel used as basis is considered
1857# read-only, and no consistency checks are made and the make
1858# system is not used on the basis kernel. If updates are required
1859# in the basis kernel ordinary make commands (without M=...) must be used.
1860
1861# We are always building only modules.
1862KBUILD_BUILTIN :=
1863KBUILD_MODULES := 1
1864
1865build-dirs := $(KBUILD_EXTMOD)
1866$(MODORDER): descend
1867	@:
1868
1869compile_commands.json: $(extmod_prefix)compile_commands.json
1870PHONY += compile_commands.json
1871
1872clean-dirs := $(KBUILD_EXTMOD)
1873clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1874	$(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1875
1876PHONY += prepare
1877# now expand this into a simple variable to reduce the cost of shell evaluations
1878prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1879prepare:
1880	@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1881		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1882		echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1883		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1884	fi
1885
1886PHONY += help
1887help:
1888	@echo  '  Building external modules.'
1889	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1890	@echo  ''
1891	@echo  '  modules         - default target, build the module(s)'
1892	@echo  '  modules_install - install the module'
1893	@echo  '  clean           - remove generated files in module directory only'
1894	@echo  ''
1895
1896# no-op for external module builds
1897PHONY += modules_prepare
1898
1899endif # KBUILD_EXTMOD
1900
1901# ---------------------------------------------------------------------------
1902# Modules
1903
1904PHONY += modules modules_install
1905
1906ifdef CONFIG_MODULES
1907
1908modules: modules_check
1909	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1910
1911PHONY += modules_check
1912modules_check: $(MODORDER)
1913	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1914
1915quiet_cmd_depmod = DEPMOD  $(MODLIB)
1916      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1917                   $(KERNELRELEASE)
1918
1919modules_install:
1920	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1921	$(call cmd,depmod)
1922
1923else # CONFIG_MODULES
1924
1925# Modules not configured
1926# ---------------------------------------------------------------------------
1927
1928modules modules_install:
1929	@echo >&2 '***'
1930	@echo >&2 '*** The present kernel configuration has modules disabled.'
1931	@echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
1932	@echo >&2 '*** to enable CONFIG_MODULES.'
1933	@echo >&2 '***'
1934	@exit 1
1935
1936endif # CONFIG_MODULES
1937
1938# Single targets
1939# ---------------------------------------------------------------------------
1940# To build individual files in subdirectories, you can do like this:
1941#
1942#   make foo/bar/baz.s
1943#
1944# The supported suffixes for single-target are listed in 'single-targets'
1945#
1946# To build only under specific subdirectories, you can do like this:
1947#
1948#   make foo/bar/baz/
1949
1950ifdef single-build
1951
1952# .ko is special because modpost is needed
1953single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1954single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
1955		$(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
1956
1957$(single-ko): single_modpost
1958	@:
1959$(single-no-ko): descend
1960	@:
1961
1962ifeq ($(KBUILD_EXTMOD),)
1963# For the single build of in-tree modules, use a temporary file to avoid
1964# the situation of modules_install installing an invalid modules.order.
1965MODORDER := .modules.tmp
1966endif
1967
1968PHONY += single_modpost
1969single_modpost: $(single-no-ko) modules_prepare
1970	$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER)
1971	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1972
1973KBUILD_MODULES := 1
1974
1975export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod_prefix), $(single-no-ko))
1976
1977# trim unrelated directories
1978build-dirs := $(foreach d, $(build-dirs), \
1979			$(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
1980
1981endif
1982
1983ifndef CONFIG_MODULES
1984KBUILD_MODULES :=
1985endif
1986
1987# Handle descending into subdirectories listed in $(build-dirs)
1988# Preset locale variables to speed up the build process. Limit locale
1989# tweaks to this spot to avoid wrong language settings when running
1990# make menuconfig etc.
1991# Error messages still appears in the original language
1992PHONY += descend $(build-dirs)
1993descend: $(build-dirs)
1994$(build-dirs): prepare
1995	$(Q)$(MAKE) $(build)=$@ \
1996	single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
1997	need-builtin=1 need-modorder=1
1998
1999clean-dirs := $(addprefix _clean_, $(clean-dirs))
2000PHONY += $(clean-dirs) clean
2001$(clean-dirs):
2002	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
2003
2004clean: $(clean-dirs)
2005	$(call cmd,rmfiles)
2006	@find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
2007		\( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
2008		-o -name '*.ko.*' \
2009		-o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
2010		-o -name '*.dwo' -o -name '*.lst' \
2011		-o -name '*.su' -o -name '*.mod' -o -name '*.usyms' \
2012		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
2013		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
2014		-o -name '*.asn1.[ch]' \
2015		-o -name '*.symtypes' -o -name 'modules.order' \
2016		-o -name '.tmp_*' \
2017		-o -name '*.c.[012]*.*' \
2018		-o -name '*.ll' \
2019		-o -name '*.gcno' \
2020		-o -name '*.*.symversions' \) -type f -print | xargs rm -f
2021
2022# Generate tags for editors
2023# ---------------------------------------------------------------------------
2024quiet_cmd_tags = GEN     $@
2025      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
2026
2027tags TAGS cscope gtags: FORCE
2028	$(call cmd,tags)
2029
2030# Script to generate missing namespace dependencies
2031# ---------------------------------------------------------------------------
2032
2033PHONY += nsdeps
2034nsdeps: export KBUILD_NSDEPS=1
2035nsdeps: modules
2036	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
2037
2038# Clang Tooling
2039# ---------------------------------------------------------------------------
2040
2041quiet_cmd_gen_compile_commands = GEN     $@
2042      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
2043
2044$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
2045	$(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
2046	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
2047	$(call if_changed,gen_compile_commands)
2048
2049targets += $(extmod_prefix)compile_commands.json
2050
2051PHONY += clang-tidy clang-analyzer
2052
2053ifdef CONFIG_CC_IS_CLANG
2054quiet_cmd_clang_tools = CHECK   $<
2055      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
2056
2057clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
2058	$(call cmd,clang_tools)
2059else
2060clang-tidy clang-analyzer:
2061	@echo "$@ requires CC=clang" >&2
2062	@false
2063endif
2064
2065# Scripts to check various things for consistency
2066# ---------------------------------------------------------------------------
2067
2068PHONY += includecheck versioncheck coccicheck export_report
2069
2070includecheck:
2071	find $(srctree)/* $(RCS_FIND_IGNORE) \
2072		-name '*.[hcS]' -type f -print | sort \
2073		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
2074
2075versioncheck:
2076	find $(srctree)/* $(RCS_FIND_IGNORE) \
2077		-name '*.[hcS]' -type f -print | sort \
2078		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
2079
2080coccicheck:
2081	$(Q)$(BASH) $(srctree)/scripts/$@
2082
2083export_report:
2084	$(PERL) $(srctree)/scripts/export_report.pl
2085
2086PHONY += checkstack kernelrelease kernelversion image_name
2087
2088# UML needs a little special treatment here.  It wants to use the host
2089# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
2090# else wants $(ARCH), including people doing cross-builds, which means
2091# that $(SUBARCH) doesn't work here.
2092ifeq ($(ARCH), um)
2093CHECKSTACK_ARCH := $(SUBARCH)
2094else
2095CHECKSTACK_ARCH := $(ARCH)
2096endif
2097checkstack:
2098	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
2099	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
2100
2101kernelrelease:
2102	@echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
2103
2104kernelversion:
2105	@echo $(KERNELVERSION)
2106
2107image_name:
2108	@echo $(KBUILD_IMAGE)
2109
2110quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
2111      cmd_rmfiles = rm -rf $(rm-files)
2112
2113# read saved command lines for existing targets
2114existing-targets := $(wildcard $(sort $(targets)))
2115
2116-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
2117
2118endif # config-build
2119endif # mixed-build
2120endif # need-sub-make
2121
2122PHONY += FORCE
2123FORCE:
2124
2125# Declare the contents of the PHONY variable as phony.  We keep that
2126# information in a variable so we can use it in if_changed and friends.
2127.PHONY: $(PHONY)
2128