xref: /openbmc/linux/Makefile (revision 115dd546)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 6
3PATCHLEVEL = 1
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 $(CF)
533NOSTDINC_FLAGS :=
534CFLAGS_MODULE   =
535RUSTFLAGS_MODULE =
536AFLAGS_MODULE   =
537LDFLAGS_MODULE  =
538CFLAGS_KERNEL	=
539RUSTFLAGS_KERNEL =
540AFLAGS_KERNEL	=
541export LDFLAGS_vmlinux =
542
543# Use USERINCLUDE when you must reference the UAPI directories only.
544USERINCLUDE    := \
545		-I$(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 -funsigned-char \
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	@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
713targets :=
714
715# Decide whether to build built-in, modular, or both.
716# Normally, just do built-in.
717
718KBUILD_MODULES :=
719KBUILD_BUILTIN := 1
720
721# If we have only "make modules", don't compile built-in objects.
722ifeq ($(MAKECMDGOALS),modules)
723  KBUILD_BUILTIN :=
724endif
725
726# If we have "make <whatever> modules", compile modules
727# in addition to whatever we do anyway.
728# Just "make" or "make all" shall build modules as well
729
730ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
731  KBUILD_MODULES := 1
732endif
733
734ifeq ($(MAKECMDGOALS),)
735  KBUILD_MODULES := 1
736endif
737
738export KBUILD_MODULES KBUILD_BUILTIN
739
740ifdef need-config
741include include/config/auto.conf
742endif
743
744ifeq ($(KBUILD_EXTMOD),)
745# Objects we will link into vmlinux / subdirs we need to visit
746core-y		:=
747drivers-y	:=
748libs-y		:= lib/
749endif # KBUILD_EXTMOD
750
751# The all: target is the default when no target is given on the
752# command line.
753# This allow a user to issue only 'make' to build a kernel including modules
754# Defaults to vmlinux, but the arch makefile usually adds further targets
755all: vmlinux
756
757CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
758ifdef CONFIG_CC_IS_GCC
759CFLAGS_GCOV	+= -fno-tree-loop-im
760endif
761export CFLAGS_GCOV
762
763# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
764ifdef CONFIG_FUNCTION_TRACER
765  CC_FLAGS_FTRACE := -pg
766endif
767
768include $(srctree)/arch/$(SRCARCH)/Makefile
769
770ifdef need-config
771ifdef may-sync-config
772# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
773# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
774# because some architectures define CROSS_COMPILE there.
775include include/config/auto.conf.cmd
776
777$(KCONFIG_CONFIG):
778	@echo >&2 '***'
779	@echo >&2 '*** Configuration file "$@" not found!'
780	@echo >&2 '***'
781	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
782	@echo >&2 '*** "make menuconfig" or "make xconfig").'
783	@echo >&2 '***'
784	@/bin/false
785
786# The actual configuration files used during the build are stored in
787# include/generated/ and include/config/. Update them if .config is newer than
788# include/config/auto.conf (which mirrors .config).
789#
790# This exploits the 'multi-target pattern rule' trick.
791# The syncconfig should be executed only once to make all the targets.
792# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
793#
794# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
795# so you cannot notice that Kconfig is waiting for the user input.
796%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
797	$(Q)$(kecho) "  SYNC    $@"
798	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
799else # !may-sync-config
800# External modules and some install targets need include/generated/autoconf.h
801# and include/config/auto.conf but do not care if they are up-to-date.
802# Use auto.conf to trigger the test
803PHONY += include/config/auto.conf
804
805include/config/auto.conf:
806	@test -e include/generated/autoconf.h -a -e $@ || (		\
807	echo >&2;							\
808	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
809	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
810	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
811	echo >&2 ;							\
812	/bin/false)
813
814endif # may-sync-config
815endif # need-config
816
817KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
818KBUILD_CFLAGS	+= $(call cc-disable-warning,frame-address,)
819KBUILD_CFLAGS	+= $(call cc-disable-warning, format-truncation)
820KBUILD_CFLAGS	+= $(call cc-disable-warning, format-overflow)
821KBUILD_CFLAGS	+= $(call cc-disable-warning, address-of-packed-member)
822
823ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
824KBUILD_CFLAGS += -O2
825KBUILD_RUSTFLAGS += -Copt-level=2
826else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
827KBUILD_CFLAGS += -Os
828KBUILD_RUSTFLAGS += -Copt-level=s
829endif
830
831# Always set `debug-assertions` and `overflow-checks` because their default
832# depends on `opt-level` and `debug-assertions`, respectively.
833KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
834KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
835
836# Tell gcc to never replace conditional load with a non-conditional one
837ifdef CONFIG_CC_IS_GCC
838# gcc-10 renamed --param=allow-store-data-races=0 to
839# -fno-allow-store-data-races.
840KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
841KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
842endif
843
844ifdef CONFIG_READABLE_ASM
845# Disable optimizations that make assembler listings hard to read.
846# reorder blocks reorders the control in the function
847# ipa clone creates specialized cloned functions
848# partial inlining inlines only parts of functions
849KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
850endif
851
852ifneq ($(CONFIG_FRAME_WARN),0)
853KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
854endif
855
856stackp-flags-y                                    := -fno-stack-protector
857stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
858stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
859
860KBUILD_CFLAGS += $(stackp-flags-y)
861
862KBUILD_CFLAGS-$(CONFIG_WERROR) += -Werror
863KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds
864
865KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings
866KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y)
867
868ifdef CONFIG_CC_IS_CLANG
869KBUILD_CPPFLAGS += -Qunused-arguments
870# The kernel builds with '-std=gnu11' so use of GNU extensions is acceptable.
871KBUILD_CFLAGS += -Wno-gnu
872else
873
874# gcc inanely warns about local variables called 'main'
875KBUILD_CFLAGS += -Wno-main
876endif
877
878# These warnings generated too much noise in a regular build.
879# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
880KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
881KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
882
883# These result in bogus false positives
884KBUILD_CFLAGS += $(call cc-disable-warning, dangling-pointer)
885
886ifdef CONFIG_FRAME_POINTER
887KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
888KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y
889else
890# Some targets (ARM with Thumb2, for example), can't be built with frame
891# pointers.  For those, we don't have FUNCTION_TRACER automatically
892# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
893# incompatible with -fomit-frame-pointer with current GCC, so we don't use
894# -fomit-frame-pointer with FUNCTION_TRACER.
895# In the Rust target specification, "frame-pointer" is set explicitly
896# to "may-omit".
897ifndef CONFIG_FUNCTION_TRACER
898KBUILD_CFLAGS	+= -fomit-frame-pointer
899endif
900endif
901
902# Initialize all stack variables with a 0xAA pattern.
903ifdef CONFIG_INIT_STACK_ALL_PATTERN
904KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
905endif
906
907# Initialize all stack variables with a zero value.
908ifdef CONFIG_INIT_STACK_ALL_ZERO
909KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
910ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
911# https://github.com/llvm/llvm-project/issues/44842
912KBUILD_CFLAGS	+= -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
913endif
914endif
915
916# While VLAs have been removed, GCC produces unreachable stack probes
917# for the randomize_kstack_offset feature. Disable it for all compilers.
918KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
919
920# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
921ifdef CONFIG_ZERO_CALL_USED_REGS
922KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
923endif
924
925ifdef CONFIG_FUNCTION_TRACER
926ifdef CONFIG_FTRACE_MCOUNT_USE_CC
927  CC_FLAGS_FTRACE	+= -mrecord-mcount
928  ifdef CONFIG_HAVE_NOP_MCOUNT
929    ifeq ($(call cc-option-yn, -mnop-mcount),y)
930      CC_FLAGS_FTRACE	+= -mnop-mcount
931      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
932    endif
933  endif
934endif
935ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
936  CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
937endif
938ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
939  ifdef CONFIG_HAVE_C_RECORDMCOUNT
940    BUILD_C_RECORDMCOUNT := y
941    export BUILD_C_RECORDMCOUNT
942  endif
943endif
944ifdef CONFIG_HAVE_FENTRY
945  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
946  ifeq ($(call cc-option-yn, -mfentry),y)
947    CC_FLAGS_FTRACE	+= -mfentry
948    CC_FLAGS_USING	+= -DCC_USING_FENTRY
949  endif
950endif
951export CC_FLAGS_FTRACE
952KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
953KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
954endif
955
956# We trigger additional mismatches with less inlining
957ifdef CONFIG_DEBUG_SECTION_MISMATCH
958KBUILD_CFLAGS += -fno-inline-functions-called-once
959endif
960
961# `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
962ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
963KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
964KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
965LDFLAGS_vmlinux += --gc-sections
966endif
967
968ifdef CONFIG_SHADOW_CALL_STACK
969ifndef CONFIG_DYNAMIC_SCS
970CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
971KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
972endif
973export CC_FLAGS_SCS
974endif
975
976ifdef CONFIG_LTO_CLANG
977ifdef CONFIG_LTO_CLANG_THIN
978CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
979KBUILD_LDFLAGS	+= --thinlto-cache-dir=$(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
1044# The allocators already balk at large sizes, so silence the compiler
1045# warnings for bounds checks involving those possible values. While
1046# -Wno-alloc-size-larger-than would normally be used here, earlier versions
1047# of gcc (<9.1) weirdly don't handle the option correctly when _other_
1048# warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX
1049# doesn't work (as it is documented to), silently resolving to "0" prior to
1050# version 9.1 (and producing an error more recently). Numeric values larger
1051# than PTRDIFF_MAX also don't work prior to version 9.1, which are silently
1052# ignored, continuing to default to PTRDIFF_MAX. So, left with no other
1053# choice, we must perform a versioned check to disable this warning.
1054# https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au
1055KBUILD_CFLAGS-$(call gcc-min-version, 90100) += -Wno-alloc-size-larger-than
1056KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
1057
1058# disable invalid "can't wrap" optimizations for signed / pointers
1059KBUILD_CFLAGS	+= -fno-strict-overflow
1060
1061# Make sure -fstack-check isn't enabled (like gentoo apparently did)
1062KBUILD_CFLAGS  += -fno-stack-check
1063
1064# conserve stack if available
1065ifdef CONFIG_CC_IS_GCC
1066KBUILD_CFLAGS   += -fconserve-stack
1067endif
1068
1069# Prohibit date/time macros, which would make the build non-deterministic
1070KBUILD_CFLAGS   += -Werror=date-time
1071
1072# enforce correct pointer usage
1073KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
1074
1075# Require designated initializers for all marked structures
1076KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
1077
1078# change __FILE__ to the relative path from the srctree
1079KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1080
1081# include additional Makefiles when needed
1082include-y			:= scripts/Makefile.extrawarn
1083include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
1084include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1085include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1086include-$(CONFIG_KMSAN)		+= scripts/Makefile.kmsan
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	+= -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),)
1174
1175build-dir	:= .
1176clean-dirs	:= $(sort . Documentation \
1177		     $(patsubst %/,%,$(filter %/, $(core-) \
1178			$(drivers-) $(libs-))))
1179
1180export ARCH_CORE	:= $(core-y)
1181export ARCH_LIB		:= $(filter %/, $(libs-y))
1182export ARCH_DRIVERS	:= $(drivers-y) $(drivers-m)
1183# Externally visible symbols (used by link-vmlinux.sh)
1184
1185KBUILD_VMLINUX_OBJS := ./built-in.a
1186ifdef CONFIG_MODULES
1187KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1188KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1189else
1190KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1191endif
1192
1193export KBUILD_VMLINUX_LIBS
1194export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1195
1196# Recurse until adjust_autoksyms.sh is satisfied
1197PHONY += autoksyms_recursive
1198ifdef CONFIG_TRIM_UNUSED_KSYMS
1199# For the kernel to actually contain only the needed exported symbols,
1200# we have to build modules as well to determine what those symbols are.
1201# (this can be evaluated only once include/config/auto.conf has been included)
1202KBUILD_MODULES := 1
1203
1204autoksyms_recursive: $(build-dir) modules.order
1205	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1206	  "$(MAKE) -f $(srctree)/Makefile autoksyms_recursive"
1207endif
1208
1209autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1210
1211quiet_cmd_autoksyms_h = GEN     $@
1212      cmd_autoksyms_h = mkdir -p $(dir $@); \
1213			$(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1214
1215$(autoksyms_h):
1216	$(call cmd,autoksyms_h)
1217
1218# '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
1219quiet_cmd_ar_vmlinux.a = AR      $@
1220      cmd_ar_vmlinux.a = \
1221	rm -f $@; \
1222	$(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
1223	$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
1224
1225targets += vmlinux.a
1226vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt autoksyms_recursive FORCE
1227	$(call if_changed,ar_vmlinux.a)
1228
1229PHONY += vmlinux_o
1230vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
1231	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
1232
1233vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
1234	@:
1235
1236PHONY += vmlinux
1237vmlinux: vmlinux.o $(KBUILD_LDS) modpost
1238	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux
1239
1240# The actual objects are generated when descending,
1241# make sure no implicit rule kicks in
1242$(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;
1243
1244filechk_kernel.release = \
1245	echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1246
1247# Store (new) KERNELRELEASE string in include/config/kernel.release
1248include/config/kernel.release: FORCE
1249	$(call filechk,kernel.release)
1250
1251# Additional helpers built in scripts/
1252# Carefully list dependencies so we do not try to build scripts twice
1253# in parallel
1254PHONY += scripts
1255scripts: scripts_basic scripts_dtc
1256	$(Q)$(MAKE) $(build)=$(@)
1257
1258# Things we need to do before we recursively start building the kernel
1259# or the modules are listed in "prepare".
1260# A multi level approach is used. prepareN is processed before prepareN-1.
1261# archprepare is used in arch Makefiles and when processed asm symlink,
1262# version.h and scripts_basic is processed / created.
1263
1264PHONY += prepare archprepare
1265
1266archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1267	asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1268	include/generated/compile.h include/generated/autoconf.h remove-stale-files
1269
1270prepare0: archprepare
1271	$(Q)$(MAKE) $(build)=scripts/mod
1272	$(Q)$(MAKE) $(build)=. prepare
1273
1274# All the preparing..
1275prepare: prepare0
1276ifdef CONFIG_RUST
1277	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh -v
1278	$(Q)$(MAKE) $(build)=rust
1279endif
1280
1281PHONY += remove-stale-files
1282remove-stale-files:
1283	$(Q)$(srctree)/scripts/remove-stale-files
1284
1285# Support for using generic headers in asm-generic
1286asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1287
1288PHONY += asm-generic uapi-asm-generic
1289asm-generic: uapi-asm-generic
1290	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1291	generic=include/asm-generic
1292uapi-asm-generic:
1293	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1294	generic=include/uapi/asm-generic
1295
1296# Generate some files
1297# ---------------------------------------------------------------------------
1298
1299# KERNELRELEASE can change from a few different places, meaning version.h
1300# needs to be updated, so this check is forced on all builds
1301
1302uts_len := 64
1303define filechk_utsrelease.h
1304	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1305	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1306	  exit 1;                                                         \
1307	fi;                                                               \
1308	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1309endef
1310
1311define filechk_version.h
1312	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1313		echo \#define LINUX_VERSION_CODE $(shell                 \
1314		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1315	else                                                             \
1316		echo \#define LINUX_VERSION_CODE $(shell                 \
1317		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1318	fi;                                                              \
1319	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1320	((c) > 255 ? 255 : (c)))';                                       \
1321	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1322	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1323	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1324endef
1325
1326$(version_h): PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1327$(version_h): SUBLEVEL := $(or $(SUBLEVEL), 0)
1328$(version_h): FORCE
1329	$(call filechk,version.h)
1330
1331include/generated/utsrelease.h: include/config/kernel.release FORCE
1332	$(call filechk,utsrelease.h)
1333
1334filechk_compile.h = $(srctree)/scripts/mkcompile_h \
1335	"$(UTS_MACHINE)" "$(CONFIG_CC_VERSION_TEXT)" "$(LD)"
1336
1337include/generated/compile.h: FORCE
1338	$(call filechk,compile.h)
1339
1340PHONY += headerdep
1341headerdep:
1342	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1343	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1344
1345# ---------------------------------------------------------------------------
1346# Kernel headers
1347
1348#Default location for installed headers
1349export INSTALL_HDR_PATH = $(objtree)/usr
1350
1351quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1352      cmd_headers_install = \
1353	mkdir -p $(INSTALL_HDR_PATH); \
1354	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1355	usr/include $(INSTALL_HDR_PATH)
1356
1357PHONY += headers_install
1358headers_install: headers
1359	$(call cmd,headers_install)
1360
1361PHONY += archheaders archscripts
1362
1363hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1364
1365PHONY += headers
1366headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1367	$(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML))
1368	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1369	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1370
1371ifdef CONFIG_HEADERS_INSTALL
1372prepare: headers
1373endif
1374
1375PHONY += scripts_unifdef
1376scripts_unifdef: scripts_basic
1377	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1378
1379# ---------------------------------------------------------------------------
1380# Install
1381
1382# Many distributions have the custom install script, /sbin/installkernel.
1383# If DKMS is installed, 'make install' will eventually recurse back
1384# to this Makefile to build and install external modules.
1385# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1386
1387quiet_cmd_install = INSTALL $(INSTALL_PATH)
1388      cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1389
1390# ---------------------------------------------------------------------------
1391# Tools
1392
1393ifdef CONFIG_OBJTOOL
1394prepare: tools/objtool
1395endif
1396
1397ifdef CONFIG_BPF
1398ifdef CONFIG_DEBUG_INFO_BTF
1399prepare: tools/bpf/resolve_btfids
1400endif
1401endif
1402
1403PHONY += resolve_btfids_clean
1404
1405resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1406
1407# tools/bpf/resolve_btfids directory might not exist
1408# in output directory, skip its clean in that case
1409resolve_btfids_clean:
1410ifneq ($(wildcard $(resolve_btfids_O)),)
1411	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1412endif
1413
1414# Clear a bunch of variables before executing the submake
1415ifeq ($(quiet),silent_)
1416tools_silent=s
1417endif
1418
1419tools/: FORCE
1420	$(Q)mkdir -p $(objtree)/tools
1421	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1422
1423tools/%: FORCE
1424	$(Q)mkdir -p $(objtree)/tools
1425	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1426
1427# ---------------------------------------------------------------------------
1428# Kernel selftest
1429
1430PHONY += kselftest
1431kselftest: headers
1432	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1433
1434kselftest-%: headers FORCE
1435	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1436
1437PHONY += kselftest-merge
1438kselftest-merge:
1439	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1440	$(Q)find $(srctree)/tools/testing/selftests -name config | \
1441		xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1442	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1443
1444# ---------------------------------------------------------------------------
1445# Devicetree files
1446
1447ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1448dtstree := arch/$(SRCARCH)/boot/dts
1449endif
1450
1451ifneq ($(dtstree),)
1452
1453%.dtb: dtbs_prepare
1454	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1455
1456%.dtbo: dtbs_prepare
1457	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1458
1459PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1460dtbs: dtbs_prepare
1461	$(Q)$(MAKE) $(build)=$(dtstree)
1462
1463# include/config/kernel.release is actually needed when installing DTBs because
1464# INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1465# dtbs_install depend on it as dtbs_install may run as root.
1466dtbs_prepare: include/config/kernel.release scripts_dtc
1467
1468ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1469export CHECK_DTBS=y
1470dtbs: dt_binding_check
1471endif
1472
1473dtbs_check: dtbs
1474
1475dtbs_install:
1476	$(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1477
1478ifdef CONFIG_OF_EARLY_FLATTREE
1479all: dtbs
1480endif
1481
1482endif
1483
1484PHONY += scripts_dtc
1485scripts_dtc: scripts_basic
1486	$(Q)$(MAKE) $(build)=scripts/dtc
1487
1488ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1489export CHECK_DT_BINDING=y
1490endif
1491
1492PHONY += dt_binding_check
1493dt_binding_check: scripts_dtc
1494	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1495
1496PHONY += dt_compatible_check
1497dt_compatible_check: dt_binding_check
1498	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1499
1500# ---------------------------------------------------------------------------
1501# Modules
1502
1503ifdef CONFIG_MODULES
1504
1505# By default, build modules as well
1506
1507all: modules
1508
1509# When we're building modules with modversions, we need to consider
1510# the built-in objects during the descend as well, in order to
1511# make sure the checksums are up to date before we record them.
1512ifdef CONFIG_MODVERSIONS
1513  KBUILD_BUILTIN := 1
1514endif
1515
1516# Build modules
1517#
1518
1519# *.ko are usually independent of vmlinux, but CONFIG_DEBUG_INFOBTF_MODULES
1520# is an exception.
1521ifdef CONFIG_DEBUG_INFO_BTF_MODULES
1522modules: vmlinux
1523endif
1524
1525modules: modules_prepare
1526
1527# Target to prepare building external modules
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 $(MODLIB)/
1564
1565endif # CONFIG_MODULES
1566
1567###
1568# Cleaning is done on three levels.
1569# make clean     Delete most generated files
1570#                Leave enough to build external modules
1571# make mrproper  Delete the current configuration, and all generated files
1572# make distclean Remove editor backup files, patch leftover files and the like
1573
1574# Directories & files removed with 'make clean'
1575CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1576	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1577	       compile_commands.json .thinlto-cache rust/test rust/doc \
1578	       .vmlinux.objs .vmlinux.export.c
1579
1580# Directories & files removed with 'make mrproper'
1581MRPROPER_FILES += include/config include/generated          \
1582		  arch/$(SRCARCH)/include/generated .objdiff \
1583		  debian snap tar-install \
1584		  .config .config.old .version \
1585		  Module.symvers \
1586		  certs/signing_key.pem \
1587		  certs/x509.genkey \
1588		  vmlinux-gdb.py \
1589		  *.spec \
1590		  rust/target.json rust/libmacros.so
1591
1592# clean - Delete most, but leave enough to build external modules
1593#
1594clean: rm-files := $(CLEAN_FILES)
1595
1596PHONY += archclean vmlinuxclean
1597
1598vmlinuxclean:
1599	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1600	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1601
1602clean: archclean vmlinuxclean resolve_btfids_clean
1603
1604# mrproper - Delete all generated files, including .config
1605#
1606mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1607mrproper-dirs      := $(addprefix _mrproper_,scripts)
1608
1609PHONY += $(mrproper-dirs) mrproper
1610$(mrproper-dirs):
1611	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1612
1613mrproper: clean $(mrproper-dirs)
1614	$(call cmd,rmfiles)
1615	@find . $(RCS_FIND_IGNORE) \
1616		\( -name '*.rmeta' \) \
1617		-type f -print | xargs rm -f
1618
1619# distclean
1620#
1621PHONY += distclean
1622
1623distclean: mrproper
1624	@find . $(RCS_FIND_IGNORE) \
1625		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1626		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1627		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1628		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1629		-type f -print | xargs rm -f
1630
1631
1632# Packaging of the kernel to various formats
1633# ---------------------------------------------------------------------------
1634
1635%src-pkg: FORCE
1636	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1637%pkg: include/config/kernel.release FORCE
1638	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1639
1640# Brief documentation of the typical targets used
1641# ---------------------------------------------------------------------------
1642
1643boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1644boards := $(sort $(notdir $(boards)))
1645board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1646board-dirs := $(sort $(notdir $(board-dirs:/=)))
1647
1648PHONY += help
1649help:
1650	@echo  'Cleaning targets:'
1651	@echo  '  clean		  - Remove most generated files but keep the config and'
1652	@echo  '                    enough build support to build external modules'
1653	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1654	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1655	@echo  ''
1656	@echo  'Configuration targets:'
1657	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1658	@echo  ''
1659	@echo  'Other generic targets:'
1660	@echo  '  all		  - Build all targets marked with [*]'
1661	@echo  '* vmlinux	  - Build the bare kernel'
1662	@echo  '* modules	  - Build all modules'
1663	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1664	@echo  '  dir/            - Build all files in dir and below'
1665	@echo  '  dir/file.[ois]  - Build specified target only'
1666	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1667	@echo  '                    (requires compiler support for LLVM assembly generation)'
1668	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1669	@echo  '                    (requires a recent binutils and recent build (System.map))'
1670	@echo  '  dir/file.ko     - Build module including final link'
1671	@echo  '  modules_prepare - Set up for building external modules'
1672	@echo  '  tags/TAGS	  - Generate tags file for editors'
1673	@echo  '  cscope	  - Generate cscope index'
1674	@echo  '  gtags           - Generate GNU GLOBAL index'
1675	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1676	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1677	@echo  '  image_name	  - Output the image name (use with make -s)'
1678	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1679	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1680	 echo  ''
1681	@echo  'Static analysers:'
1682	@echo  '  checkstack      - Generate a list of stack hogs'
1683	@echo  '  versioncheck    - Sanity check on version.h usage'
1684	@echo  '  includecheck    - Check for duplicate included header files'
1685	@echo  '  export_report   - List the usages of all exported symbols'
1686	@echo  '  headerdep       - Detect inclusion cycles in headers'
1687	@echo  '  coccicheck      - Check with Coccinelle'
1688	@echo  '  clang-analyzer  - Check with clang static analyzer'
1689	@echo  '  clang-tidy      - Check with clang-tidy'
1690	@echo  ''
1691	@echo  'Tools:'
1692	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1693	@echo  ''
1694	@echo  'Kernel selftest:'
1695	@echo  '  kselftest         - Build and run kernel selftest'
1696	@echo  '                      Build, install, and boot kernel before'
1697	@echo  '                      running kselftest on it'
1698	@echo  '                      Run as root for full coverage'
1699	@echo  '  kselftest-all     - Build kernel selftest'
1700	@echo  '  kselftest-install - Build and install kernel selftest'
1701	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1702	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1703	@echo  '		      kselftest to existing .config.'
1704	@echo  ''
1705	@echo  'Rust targets:'
1706	@echo  '  rustavailable   - Checks whether the Rust toolchain is'
1707	@echo  '		    available and, if not, explains why.'
1708	@echo  '  rustfmt	  - Reformat all the Rust code in the kernel'
1709	@echo  '  rustfmtcheck	  - Checks if all the Rust code in the kernel'
1710	@echo  '		    is formatted, printing a diff otherwise.'
1711	@echo  '  rustdoc	  - Generate Rust documentation'
1712	@echo  '		    (requires kernel .config)'
1713	@echo  '  rusttest        - Runs the Rust tests'
1714	@echo  '                    (requires kernel .config; downloads external repos)'
1715	@echo  '  rust-analyzer	  - Generate rust-project.json rust-analyzer support file'
1716	@echo  '		    (requires kernel .config)'
1717	@echo  '  dir/file.[os]   - Build specified target only'
1718	@echo  '  dir/file.rsi    - Build macro expanded source, similar to C preprocessing.'
1719	@echo  '                    Run with RUSTFMT=n to skip reformatting if needed.'
1720	@echo  '                    The output is not intended to be compilable.'
1721	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1722	@echo  ''
1723	@$(if $(dtstree), \
1724		echo 'Devicetree:'; \
1725		echo '* dtbs             - Build device tree blobs for enabled boards'; \
1726		echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1727		echo '  dt_binding_check - Validate device tree binding documents'; \
1728		echo '  dtbs_check       - Validate device tree source files';\
1729		echo '')
1730
1731	@echo 'Userspace tools targets:'
1732	@echo '  use "make tools/help"'
1733	@echo '  or  "cd tools; make help"'
1734	@echo  ''
1735	@echo  'Kernel packaging:'
1736	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1737	@echo  ''
1738	@echo  'Documentation targets:'
1739	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1740	@echo  ''
1741	@echo  'Architecture specific targets ($(SRCARCH)):'
1742	@$(or $(archhelp),\
1743		echo '  No architecture specific help defined for $(SRCARCH)')
1744	@echo  ''
1745	@$(if $(boards), \
1746		$(foreach b, $(boards), \
1747		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1748		echo '')
1749	@$(if $(board-dirs), \
1750		$(foreach b, $(board-dirs), \
1751		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1752		printf "  %-16s - Show all of the above\\n" help-boards; \
1753		echo '')
1754
1755	@echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1756	@echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1757	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1758	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1759	@echo  '                       (sparse by default)'
1760	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1761	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1762	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1763	@echo  '		1: warnings which may be relevant and do not occur too often'
1764	@echo  '		2: warnings which occur quite often but may still be relevant'
1765	@echo  '		3: more obscure warnings, can most likely be ignored'
1766	@echo  '		e: warnings are being treated as errors'
1767	@echo  '		Multiple levels can be combined with W=12 or W=123'
1768	@echo  ''
1769	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1770	@echo  'For further info see the ./README file'
1771
1772
1773help-board-dirs := $(addprefix help-,$(board-dirs))
1774
1775help-boards: $(help-board-dirs)
1776
1777boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1778
1779$(help-board-dirs): help-%:
1780	@echo  'Architecture specific targets ($(SRCARCH) $*):'
1781	@$(if $(boards-per-dir), \
1782		$(foreach b, $(boards-per-dir), \
1783		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1784		echo '')
1785
1786
1787# Documentation targets
1788# ---------------------------------------------------------------------------
1789DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1790	       linkcheckdocs dochelp refcheckdocs texinfodocs infodocs
1791PHONY += $(DOC_TARGETS)
1792$(DOC_TARGETS):
1793	$(Q)$(MAKE) $(build)=Documentation $@
1794
1795
1796# Rust targets
1797# ---------------------------------------------------------------------------
1798
1799# "Is Rust available?" target
1800PHONY += rustavailable
1801rustavailable:
1802	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh -v && echo "Rust is available!"
1803
1804# Documentation target
1805#
1806# Using the singular to avoid running afoul of `no-dot-config-targets`.
1807PHONY += rustdoc
1808rustdoc: prepare
1809	$(Q)$(MAKE) $(build)=rust $@
1810
1811# Testing target
1812PHONY += rusttest
1813rusttest: prepare
1814	$(Q)$(MAKE) $(build)=rust $@
1815
1816# Formatting targets
1817PHONY += rustfmt rustfmtcheck
1818
1819# We skip `rust/alloc` since we want to minimize the diff w.r.t. upstream.
1820#
1821# We match using absolute paths since `find` does not resolve them
1822# when matching, which is a problem when e.g. `srctree` is `..`.
1823# We `grep` afterwards in order to remove the directory entry itself.
1824rustfmt:
1825	$(Q)find $(abs_srctree) -type f -name '*.rs' \
1826		-o -path $(abs_srctree)/rust/alloc -prune \
1827		-o -path $(abs_objtree)/rust/test -prune \
1828		| grep -Fv $(abs_srctree)/rust/alloc \
1829		| grep -Fv $(abs_objtree)/rust/test \
1830		| grep -Fv generated \
1831		| xargs $(RUSTFMT) $(rustfmt_flags)
1832
1833rustfmtcheck: rustfmt_flags = --check
1834rustfmtcheck: rustfmt
1835
1836# IDE support targets
1837PHONY += rust-analyzer
1838rust-analyzer:
1839	$(Q)$(MAKE) $(build)=rust $@
1840
1841# Misc
1842# ---------------------------------------------------------------------------
1843
1844PHONY += scripts_gdb
1845scripts_gdb: prepare0
1846	$(Q)$(MAKE) $(build)=scripts/gdb
1847	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1848
1849ifdef CONFIG_GDB_SCRIPTS
1850all: scripts_gdb
1851endif
1852
1853else # KBUILD_EXTMOD
1854
1855###
1856# External module support.
1857# When building external modules the kernel used as basis is considered
1858# read-only, and no consistency checks are made and the make
1859# system is not used on the basis kernel. If updates are required
1860# in the basis kernel ordinary make commands (without M=...) must be used.
1861
1862# We are always building only modules.
1863KBUILD_BUILTIN :=
1864KBUILD_MODULES := 1
1865
1866build-dir := $(KBUILD_EXTMOD)
1867
1868compile_commands.json: $(extmod_prefix)compile_commands.json
1869PHONY += compile_commands.json
1870
1871clean-dirs := $(KBUILD_EXTMOD)
1872clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1873	$(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1874
1875PHONY += prepare
1876# now expand this into a simple variable to reduce the cost of shell evaluations
1877prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1878prepare:
1879	@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1880		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1881		echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1882		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1883	fi
1884
1885PHONY += help
1886help:
1887	@echo  '  Building external modules.'
1888	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1889	@echo  ''
1890	@echo  '  modules         - default target, build the module(s)'
1891	@echo  '  modules_install - install the module'
1892	@echo  '  clean           - remove generated files in module directory only'
1893	@echo  ''
1894
1895endif # KBUILD_EXTMOD
1896
1897# ---------------------------------------------------------------------------
1898# Modules
1899
1900PHONY += modules modules_install modules_prepare
1901
1902ifdef CONFIG_MODULES
1903
1904$(MODORDER): $(build-dir)
1905	@:
1906
1907# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
1908# This is solely useful to speed up test compiles.
1909modules: modpost
1910ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1911	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1912endif
1913
1914PHONY += modules_check
1915modules_check: $(MODORDER)
1916	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1917
1918quiet_cmd_depmod = DEPMOD  $(MODLIB)
1919      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1920                   $(KERNELRELEASE)
1921
1922modules_install:
1923	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1924	$(call cmd,depmod)
1925
1926else # CONFIG_MODULES
1927
1928# Modules not configured
1929# ---------------------------------------------------------------------------
1930
1931modules modules_install:
1932	@echo >&2 '***'
1933	@echo >&2 '*** The present kernel configuration has modules disabled.'
1934	@echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
1935	@echo >&2 '*** to enable CONFIG_MODULES.'
1936	@echo >&2 '***'
1937	@exit 1
1938
1939KBUILD_MODULES :=
1940
1941endif # CONFIG_MODULES
1942
1943PHONY += modpost
1944modpost: $(if $(single-build),, $(if $(KBUILD_BUILTIN), vmlinux.o)) \
1945	 $(if $(KBUILD_MODULES), modules_check)
1946	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1947
1948# Single targets
1949# ---------------------------------------------------------------------------
1950# To build individual files in subdirectories, you can do like this:
1951#
1952#   make foo/bar/baz.s
1953#
1954# The supported suffixes for single-target are listed in 'single-targets'
1955#
1956# To build only under specific subdirectories, you can do like this:
1957#
1958#   make foo/bar/baz/
1959
1960ifdef single-build
1961
1962# .ko is special because modpost is needed
1963single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1964single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
1965		$(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
1966
1967$(single-ko): single_modules
1968	@:
1969$(single-no-ko): $(build-dir)
1970	@:
1971
1972# Remove MODORDER when done because it is not the real one.
1973PHONY += single_modules
1974single_modules: $(single-no-ko) modules_prepare
1975	$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER)
1976	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1977ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1978	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1979endif
1980	$(Q)rm -f $(MODORDER)
1981
1982single-goals := $(addprefix $(build-dir)/, $(single-no-ko))
1983
1984KBUILD_MODULES := 1
1985
1986endif
1987
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 += $(build-dir)
1993$(build-dir): prepare
1994	$(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)
1995
1996clean-dirs := $(addprefix _clean_, $(clean-dirs))
1997PHONY += $(clean-dirs) clean
1998$(clean-dirs):
1999	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
2000
2001clean: $(clean-dirs)
2002	$(call cmd,rmfiles)
2003	@find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
2004		\( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
2005		-o -name '*.ko.*' \
2006		-o -name '*.dtb' -o -name '*.dtbo' \
2007		-o -name '*.dtb.S' -o -name '*.dtbo.S' \
2008		-o -name '*.dt.yaml' \
2009		-o -name '*.dwo' -o -name '*.lst' \
2010		-o -name '*.su' -o -name '*.mod' -o -name '*.usyms' \
2011		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
2012		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
2013		-o -name '*.asn1.[ch]' \
2014		-o -name '*.symtypes' -o -name 'modules.order' \
2015		-o -name '.tmp_*' \
2016		-o -name '*.c.[012]*.*' \
2017		-o -name '*.ll' \
2018		-o -name '*.gcno' \
2019		-o -name '*.*.symversions' \) -type f -print | xargs rm -f
2020
2021# Generate tags for editors
2022# ---------------------------------------------------------------------------
2023quiet_cmd_tags = GEN     $@
2024      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
2025
2026tags TAGS cscope gtags: FORCE
2027	$(call cmd,tags)
2028
2029# Script to generate missing namespace dependencies
2030# ---------------------------------------------------------------------------
2031
2032PHONY += nsdeps
2033nsdeps: export KBUILD_NSDEPS=1
2034nsdeps: modules
2035	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
2036
2037# Clang Tooling
2038# ---------------------------------------------------------------------------
2039
2040quiet_cmd_gen_compile_commands = GEN     $@
2041      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
2042
2043$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
2044	$(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS)) \
2045	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
2046	$(call if_changed,gen_compile_commands)
2047
2048targets += $(extmod_prefix)compile_commands.json
2049
2050PHONY += clang-tidy clang-analyzer
2051
2052ifdef CONFIG_CC_IS_CLANG
2053quiet_cmd_clang_tools = CHECK   $<
2054      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
2055
2056clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
2057	$(call cmd,clang_tools)
2058else
2059clang-tidy clang-analyzer:
2060	@echo "$@ requires CC=clang" >&2
2061	@false
2062endif
2063
2064# Scripts to check various things for consistency
2065# ---------------------------------------------------------------------------
2066
2067PHONY += includecheck versioncheck coccicheck export_report
2068
2069includecheck:
2070	find $(srctree)/* $(RCS_FIND_IGNORE) \
2071		-name '*.[hcS]' -type f -print | sort \
2072		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
2073
2074versioncheck:
2075	find $(srctree)/* $(RCS_FIND_IGNORE) \
2076		-name '*.[hcS]' -type f -print | sort \
2077		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
2078
2079coccicheck:
2080	$(Q)$(BASH) $(srctree)/scripts/$@
2081
2082export_report:
2083	$(PERL) $(srctree)/scripts/export_report.pl
2084
2085PHONY += checkstack kernelrelease kernelversion image_name
2086
2087# UML needs a little special treatment here.  It wants to use the host
2088# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
2089# else wants $(ARCH), including people doing cross-builds, which means
2090# that $(SUBARCH) doesn't work here.
2091ifeq ($(ARCH), um)
2092CHECKSTACK_ARCH := $(SUBARCH)
2093else
2094CHECKSTACK_ARCH := $(ARCH)
2095endif
2096checkstack:
2097	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
2098	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
2099
2100kernelrelease:
2101	@echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
2102
2103kernelversion:
2104	@echo $(KERNELVERSION)
2105
2106image_name:
2107	@echo $(KBUILD_IMAGE)
2108
2109quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
2110      cmd_rmfiles = rm -rf $(rm-files)
2111
2112# read saved command lines for existing targets
2113existing-targets := $(wildcard $(sort $(targets)))
2114
2115-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
2116
2117endif # config-build
2118endif # mixed-build
2119endif # need-sub-make
2120
2121PHONY += FORCE
2122FORCE:
2123
2124# Declare the contents of the PHONY variable as phony.  We keep that
2125# information in a variable so we can use it in if_changed and friends.
2126.PHONY: $(PHONY)
2127