xref: /linux/Makefile (revision 1517d90cfafe0f95fd7863d04e1596f7beb7dfa8)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 5
3PATCHLEVEL = 4
4SUBLEVEL = 0
5EXTRAVERSION = -rc1
6NAME = Bobtail Squid
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# That's our default target when none is given on the command line
15PHONY := _all
16_all:
17
18# We are using a recursive build, so we need to do a little thinking
19# to get the ordering right.
20#
21# Most importantly: sub-Makefiles should only ever modify files in
22# their own directory. If in some directory we have a dependency on
23# a file in another dir (which doesn't happen often, but it's often
24# unavoidable when linking the built-in.a targets which finally
25# turn into vmlinux), we will call a sub make in that other dir, and
26# after that we are sure that everything which is in that other dir
27# is now up to date.
28#
29# The only cases where we need to modify files which have global
30# effects are thus separated out and done before the recursive
31# descending is started. They are now explicitly listed as the
32# prepare rule.
33
34ifneq ($(sub_make_done),1)
35
36# Do not use make's built-in rules and variables
37# (this increases performance and avoids hard-to-debug behaviour)
38MAKEFLAGS += -rR
39
40# Avoid funny character set dependencies
41unexport LC_ALL
42LC_COLLATE=C
43LC_NUMERIC=C
44export LC_COLLATE LC_NUMERIC
45
46# Avoid interference with shell env settings
47unexport GREP_OPTIONS
48
49# Beautify output
50# ---------------------------------------------------------------------------
51#
52# Normally, we echo the whole command before executing it. By making
53# that echo $($(quiet)$(cmd)), we now have the possibility to set
54# $(quiet) to choose other forms of output instead, e.g.
55#
56#         quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
57#         cmd_cc_o_c       = $(CC) $(c_flags) -c -o $@ $<
58#
59# If $(quiet) is empty, the whole command will be printed.
60# If it is set to "quiet_", only the short version will be printed.
61# If it is set to "silent_", nothing will be printed at all, since
62# the variable $(silent_cmd_cc_o_c) doesn't exist.
63#
64# A simple variant is to prefix commands with $(Q) - that's useful
65# for commands that shall be hidden in non-verbose mode.
66#
67#	$(Q)ln $@ :<
68#
69# If KBUILD_VERBOSE equals 0 then the above command will be hidden.
70# If KBUILD_VERBOSE equals 1 then the above command is displayed.
71#
72# To put more focus on warnings, be less verbose as default
73# Use 'make V=1' to see the full commands
74
75ifeq ("$(origin V)", "command line")
76  KBUILD_VERBOSE = $(V)
77endif
78ifndef KBUILD_VERBOSE
79  KBUILD_VERBOSE = 0
80endif
81
82ifeq ($(KBUILD_VERBOSE),1)
83  quiet =
84  Q =
85else
86  quiet=quiet_
87  Q = @
88endif
89
90# If the user is running make -s (silent mode), suppress echoing of
91# commands
92
93ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
94  quiet=silent_
95endif
96
97export quiet Q KBUILD_VERBOSE
98
99# Kbuild will save output files in the current working directory.
100# This does not need to match to the root of the kernel source tree.
101#
102# For example, you can do this:
103#
104#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
105#
106# If you want to save output files in a different location, there are
107# two syntaxes to specify it.
108#
109# 1) O=
110# Use "make O=dir/to/store/output/files/"
111#
112# 2) Set KBUILD_OUTPUT
113# Set the environment variable KBUILD_OUTPUT to point to the output directory.
114# export KBUILD_OUTPUT=dir/to/store/output/files/; make
115#
116# The O= assignment takes precedence over the KBUILD_OUTPUT environment
117# variable.
118
119# Do we want to change the working directory?
120ifeq ("$(origin O)", "command line")
121  KBUILD_OUTPUT := $(O)
122endif
123
124ifneq ($(KBUILD_OUTPUT),)
125# Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
126# expand a shell special character '~'. We use a somewhat tedious way here.
127abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
128$(if $(abs_objtree),, \
129     $(error failed to create output directory "$(KBUILD_OUTPUT)"))
130
131# $(realpath ...) resolves symlinks
132abs_objtree := $(realpath $(abs_objtree))
133else
134abs_objtree := $(CURDIR)
135endif # ifneq ($(KBUILD_OUTPUT),)
136
137ifeq ($(abs_objtree),$(CURDIR))
138# Suppress "Entering directory ..." unless we are changing the work directory.
139MAKEFLAGS += --no-print-directory
140else
141need-sub-make := 1
142endif
143
144abs_srctree := $(realpath $(dir $(lastword $(MAKEFILE_LIST))))
145
146ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
147$(error source directory cannot contain spaces or colons)
148endif
149
150ifneq ($(abs_srctree),$(abs_objtree))
151# Look for make include files relative to root of kernel src
152#
153# This does not become effective immediately because MAKEFLAGS is re-parsed
154# once after the Makefile is read. We need to invoke sub-make.
155MAKEFLAGS += --include-dir=$(abs_srctree)
156need-sub-make := 1
157endif
158
159ifneq ($(filter 3.%,$(MAKE_VERSION)),)
160# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
161# We need to invoke sub-make to avoid implicit rules in the top Makefile.
162need-sub-make := 1
163# Cancel implicit rules for this Makefile.
164$(lastword $(MAKEFILE_LIST)): ;
165endif
166
167export abs_srctree abs_objtree
168export sub_make_done := 1
169
170ifeq ($(need-sub-make),1)
171
172PHONY += $(MAKECMDGOALS) sub-make
173
174$(filter-out _all sub-make $(lastword $(MAKEFILE_LIST)), $(MAKECMDGOALS)) _all: sub-make
175	@:
176
177# Invoke a second make in the output directory, passing relevant variables
178sub-make:
179	$(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
180
181endif # need-sub-make
182endif # sub_make_done
183
184# We process the rest of the Makefile if this is the final invocation of make
185ifeq ($(need-sub-make),)
186
187# Do not print "Entering directory ...",
188# but we want to display it when entering to the output directory
189# so that IDEs/editors are able to understand relative filenames.
190MAKEFLAGS += --no-print-directory
191
192# Call a source code checker (by default, "sparse") as part of the
193# C compilation.
194#
195# Use 'make C=1' to enable checking of only re-compiled files.
196# Use 'make C=2' to enable checking of *all* source files, regardless
197# of whether they are re-compiled or not.
198#
199# See the file "Documentation/dev-tools/sparse.rst" for more details,
200# including where to get the "sparse" utility.
201
202ifeq ("$(origin C)", "command line")
203  KBUILD_CHECKSRC = $(C)
204endif
205ifndef KBUILD_CHECKSRC
206  KBUILD_CHECKSRC = 0
207endif
208
209# Use make M=dir to specify directory of external module to build
210# Old syntax make ... SUBDIRS=$PWD is still supported
211# Setting the environment variable KBUILD_EXTMOD take precedence
212ifdef SUBDIRS
213  $(warning ================= WARNING ================)
214  $(warning 'SUBDIRS' will be removed after Linux 5.3)
215  $(warning )
216  $(warning If you are building an individual subdirectory)
217  $(warning in the kernel tree, you can do like this:)
218  $(warning $$ make path/to/dir/you/want/to/build/)
219  $(warning (Do not forget the trailing slash))
220  $(warning )
221  $(warning If you are building an external module,)
222  $(warning Please use 'M=' or 'KBUILD_EXTMOD' instead)
223  $(warning ==========================================)
224  KBUILD_EXTMOD ?= $(SUBDIRS)
225endif
226
227ifeq ("$(origin M)", "command line")
228  KBUILD_EXTMOD := $(M)
229endif
230
231export KBUILD_CHECKSRC KBUILD_EXTMOD
232
233extmod-prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
234
235ifeq ($(abs_srctree),$(abs_objtree))
236        # building in the source tree
237        srctree := .
238	building_out_of_srctree :=
239else
240        ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
241                # building in a subdirectory of the source tree
242                srctree := ..
243        else
244                srctree := $(abs_srctree)
245        endif
246	building_out_of_srctree := 1
247endif
248
249ifneq ($(KBUILD_ABS_SRCTREE),)
250srctree := $(abs_srctree)
251endif
252
253objtree		:= .
254VPATH		:= $(srctree)
255
256export building_out_of_srctree srctree objtree VPATH
257
258# To make sure we do not include .config for any of the *config targets
259# catch them early, and hand them over to scripts/kconfig/Makefile
260# It is allowed to specify more targets when calling make, including
261# mixing *config targets and build targets.
262# For example 'make oldconfig all'.
263# Detect when mixed targets is specified, and make a second invocation
264# of make so .config is not included in this case either (for *config).
265
266version_h := include/generated/uapi/linux/version.h
267old_version_h := include/linux/version.h
268
269clean-targets := %clean mrproper cleandocs
270no-dot-config-targets := $(clean-targets) \
271			 cscope gtags TAGS tags help% %docs check% coccicheck \
272			 $(version_h) headers headers_% archheaders archscripts \
273			 %asm-generic kernelversion %src-pkg
274no-sync-config-targets := $(no-dot-config-targets) install %install \
275			   kernelrelease
276single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/
277
278config-build	:=
279mixed-build	:=
280need-config	:= 1
281may-sync-config	:= 1
282single-build	:=
283
284ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
285	ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
286		need-config :=
287	endif
288endif
289
290ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
291	ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
292		may-sync-config :=
293	endif
294endif
295
296ifneq ($(KBUILD_EXTMOD),)
297	may-sync-config :=
298endif
299
300ifeq ($(KBUILD_EXTMOD),)
301        ifneq ($(filter config %config,$(MAKECMDGOALS)),)
302		config-build := 1
303                ifneq ($(words $(MAKECMDGOALS)),1)
304			mixed-build := 1
305                endif
306        endif
307endif
308
309# We cannot build single targets and the others at the same time
310ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
311	single-build := 1
312	ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
313		mixed-build := 1
314	endif
315endif
316
317# For "make -j clean all", "make -j mrproper defconfig all", etc.
318ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
319        ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
320		mixed-build := 1
321        endif
322endif
323
324# install and modules_install need also be processed one by one
325ifneq ($(filter install,$(MAKECMDGOALS)),)
326        ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
327		mixed-build := 1
328        endif
329endif
330
331ifdef mixed-build
332# ===========================================================================
333# We're called with mixed targets (*config and build targets).
334# Handle them one by one.
335
336PHONY += $(MAKECMDGOALS) __build_one_by_one
337
338$(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
339	@:
340
341__build_one_by_one:
342	$(Q)set -e; \
343	for i in $(MAKECMDGOALS); do \
344		$(MAKE) -f $(srctree)/Makefile $$i; \
345	done
346
347else # !mixed-build
348
349include scripts/Kbuild.include
350
351# Read KERNELRELEASE from include/config/kernel.release (if it exists)
352KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
353KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
354export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
355
356include scripts/subarch.include
357
358# Cross compiling and selecting different set of gcc/bin-utils
359# ---------------------------------------------------------------------------
360#
361# When performing cross compilation for other architectures ARCH shall be set
362# to the target architecture. (See arch/* for the possibilities).
363# ARCH can be set during invocation of make:
364# make ARCH=ia64
365# Another way is to have ARCH set in the environment.
366# The default ARCH is the host where make is executed.
367
368# CROSS_COMPILE specify the prefix used for all executables used
369# during compilation. Only gcc and related bin-utils executables
370# are prefixed with $(CROSS_COMPILE).
371# CROSS_COMPILE can be set on the command line
372# make CROSS_COMPILE=ia64-linux-
373# Alternatively CROSS_COMPILE can be set in the environment.
374# Default value for CROSS_COMPILE is not to prefix executables
375# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
376ARCH		?= $(SUBARCH)
377
378# Architecture as present in compile.h
379UTS_MACHINE 	:= $(ARCH)
380SRCARCH 	:= $(ARCH)
381
382# Additional ARCH settings for x86
383ifeq ($(ARCH),i386)
384        SRCARCH := x86
385endif
386ifeq ($(ARCH),x86_64)
387        SRCARCH := x86
388endif
389
390# Additional ARCH settings for sparc
391ifeq ($(ARCH),sparc32)
392       SRCARCH := sparc
393endif
394ifeq ($(ARCH),sparc64)
395       SRCARCH := sparc
396endif
397
398# Additional ARCH settings for sh
399ifeq ($(ARCH),sh64)
400       SRCARCH := sh
401endif
402
403KCONFIG_CONFIG	?= .config
404export KCONFIG_CONFIG
405
406# SHELL used by kbuild
407CONFIG_SHELL := sh
408
409HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
410HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
411HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
412
413HOSTCC       = gcc
414HOSTCXX      = g++
415KBUILD_HOSTCFLAGS   := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 \
416		-fomit-frame-pointer -std=gnu89 $(HOST_LFS_CFLAGS) \
417		$(HOSTCFLAGS)
418KBUILD_HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
419KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
420KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
421
422# Make variables (CC, etc...)
423AS		= $(CROSS_COMPILE)as
424LD		= $(CROSS_COMPILE)ld
425CC		= $(CROSS_COMPILE)gcc
426CPP		= $(CC) -E
427AR		= $(CROSS_COMPILE)ar
428NM		= $(CROSS_COMPILE)nm
429STRIP		= $(CROSS_COMPILE)strip
430OBJCOPY		= $(CROSS_COMPILE)objcopy
431OBJDUMP		= $(CROSS_COMPILE)objdump
432OBJSIZE		= $(CROSS_COMPILE)size
433PAHOLE		= pahole
434LEX		= flex
435YACC		= bison
436AWK		= awk
437INSTALLKERNEL  := installkernel
438DEPMOD		= /sbin/depmod
439PERL		= perl
440PYTHON		= python
441PYTHON2		= python2
442PYTHON3		= python3
443CHECK		= sparse
444BASH		= bash
445
446CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
447		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
448NOSTDINC_FLAGS :=
449CFLAGS_MODULE   =
450AFLAGS_MODULE   =
451LDFLAGS_MODULE  =
452CFLAGS_KERNEL	=
453AFLAGS_KERNEL	=
454LDFLAGS_vmlinux =
455
456# Use USERINCLUDE when you must reference the UAPI directories only.
457USERINCLUDE    := \
458		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
459		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
460		-I$(srctree)/include/uapi \
461		-I$(objtree)/include/generated/uapi \
462                -include $(srctree)/include/linux/kconfig.h
463
464# Use LINUXINCLUDE when you must reference the include/ directory.
465# Needed to be compatible with the O= option
466LINUXINCLUDE    := \
467		-I$(srctree)/arch/$(SRCARCH)/include \
468		-I$(objtree)/arch/$(SRCARCH)/include/generated \
469		$(if $(building_out_of_srctree),-I$(srctree)/include) \
470		-I$(objtree)/include \
471		$(USERINCLUDE)
472
473KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
474KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
475		   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
476		   -Werror=implicit-function-declaration -Werror=implicit-int \
477		   -Wno-format-security \
478		   -std=gnu89
479KBUILD_CPPFLAGS := -D__KERNEL__
480KBUILD_AFLAGS_KERNEL :=
481KBUILD_CFLAGS_KERNEL :=
482KBUILD_AFLAGS_MODULE  := -DMODULE
483KBUILD_CFLAGS_MODULE  := -DMODULE
484KBUILD_LDFLAGS_MODULE :=
485export KBUILD_LDS_MODULE := $(srctree)/scripts/module-common.lds
486KBUILD_LDFLAGS :=
487GCC_PLUGINS_CFLAGS :=
488CLANG_FLAGS :=
489
490export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE AS LD CC
491export CPP AR NM STRIP OBJCOPY OBJDUMP OBJSIZE PAHOLE LEX YACC AWK INSTALLKERNEL
492export PERL PYTHON PYTHON2 PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
493export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
494
495export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
496export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
497export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN
498export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
499export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
500export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
501export KBUILD_ARFLAGS
502
503# Files to ignore in find ... statements
504
505export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
506			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
507			  -prune -o
508export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
509			 --exclude CVS --exclude .pc --exclude .hg --exclude .git
510
511# ===========================================================================
512# Rules shared between *config targets and build targets
513
514# Basic helpers built in scripts/basic/
515PHONY += scripts_basic
516scripts_basic:
517	$(Q)$(MAKE) $(build)=scripts/basic
518	$(Q)rm -f .tmp_quiet_recordmcount
519
520PHONY += outputmakefile
521# Before starting out-of-tree build, make sure the source tree is clean.
522# outputmakefile generates a Makefile in the output directory, if using a
523# separate output directory. This allows convenient use of make in the
524# output directory.
525# At the same time when output Makefile generated, generate .gitignore to
526# ignore whole output directory
527outputmakefile:
528ifdef building_out_of_srctree
529	$(Q)if [ -f $(srctree)/.config -o \
530		 -d $(srctree)/include/config -o \
531		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
532		echo >&2 "***"; \
533		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
534		echo >&2 "*** in $(abs_srctree)";\
535		echo >&2 "***"; \
536		false; \
537	fi
538	$(Q)ln -fsn $(srctree) source
539	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
540	$(Q)test -e .gitignore || \
541	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
542endif
543
544ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
545ifneq ($(CROSS_COMPILE),)
546CLANG_FLAGS	+= --target=$(notdir $(CROSS_COMPILE:%-=%))
547GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
548CLANG_FLAGS	+= --prefix=$(GCC_TOOLCHAIN_DIR)
549GCC_TOOLCHAIN	:= $(realpath $(GCC_TOOLCHAIN_DIR)/..)
550endif
551ifneq ($(GCC_TOOLCHAIN),)
552CLANG_FLAGS	+= --gcc-toolchain=$(GCC_TOOLCHAIN)
553endif
554ifeq ($(shell $(AS) --version 2>&1 | head -n 1 | grep clang),)
555CLANG_FLAGS	+= -no-integrated-as
556endif
557CLANG_FLAGS	+= -Werror=unknown-warning-option
558KBUILD_CFLAGS	+= $(CLANG_FLAGS)
559KBUILD_AFLAGS	+= $(CLANG_FLAGS)
560export CLANG_FLAGS
561endif
562
563# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
564# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
565# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
566# and from include/config/auto.conf.cmd to detect the compiler upgrade.
567CC_VERSION_TEXT = $(shell $(CC) --version 2>/dev/null | head -n 1)
568
569ifdef config-build
570# ===========================================================================
571# *config targets only - make sure prerequisites are updated, and descend
572# in scripts/kconfig to make the *config target
573
574# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
575# KBUILD_DEFCONFIG may point out an alternative default configuration
576# used for 'make defconfig'
577include arch/$(SRCARCH)/Makefile
578export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
579
580config: outputmakefile scripts_basic FORCE
581	$(Q)$(MAKE) $(build)=scripts/kconfig $@
582
583%config: outputmakefile scripts_basic FORCE
584	$(Q)$(MAKE) $(build)=scripts/kconfig $@
585
586else #!config-build
587# ===========================================================================
588# Build targets only - this includes vmlinux, arch specific targets, clean
589# targets and others. In general all targets except *config targets.
590
591# If building an external module we do not care about the all: rule
592# but instead _all depend on modules
593PHONY += all
594ifeq ($(KBUILD_EXTMOD),)
595_all: all
596else
597_all: modules
598endif
599
600# Decide whether to build built-in, modular, or both.
601# Normally, just do built-in.
602
603KBUILD_MODULES :=
604KBUILD_BUILTIN := 1
605
606# If we have only "make modules", don't compile built-in objects.
607# When we're building modules with modversions, we need to consider
608# the built-in objects during the descend as well, in order to
609# make sure the checksums are up to date before we record them.
610
611ifeq ($(MAKECMDGOALS),modules)
612  KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
613endif
614
615# If we have "make <whatever> modules", compile modules
616# in addition to whatever we do anyway.
617# Just "make" or "make all" shall build modules as well
618
619ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
620  KBUILD_MODULES := 1
621endif
622
623ifeq ($(MAKECMDGOALS),)
624  KBUILD_MODULES := 1
625endif
626
627export KBUILD_MODULES KBUILD_BUILTIN
628
629ifdef need-config
630include include/config/auto.conf
631endif
632
633ifeq ($(KBUILD_EXTMOD),)
634# Objects we will link into vmlinux / subdirs we need to visit
635init-y		:= init/
636drivers-y	:= drivers/ sound/
637drivers-$(CONFIG_SAMPLES) += samples/
638drivers-$(CONFIG_KERNEL_HEADER_TEST) += include/
639net-y		:= net/
640libs-y		:= lib/
641core-y		:= usr/
642virt-y		:= virt/
643endif # KBUILD_EXTMOD
644
645# The all: target is the default when no target is given on the
646# command line.
647# This allow a user to issue only 'make' to build a kernel including modules
648# Defaults to vmlinux, but the arch makefile usually adds further targets
649all: vmlinux
650
651CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage \
652	$(call cc-option,-fno-tree-loop-im) \
653	$(call cc-disable-warning,maybe-uninitialized,)
654export CFLAGS_GCOV
655
656# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
657ifdef CONFIG_FUNCTION_TRACER
658  CC_FLAGS_FTRACE := -pg
659endif
660
661RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
662RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
663RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
664RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
665RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
666RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
667export RETPOLINE_CFLAGS
668export RETPOLINE_VDSO_CFLAGS
669
670include arch/$(SRCARCH)/Makefile
671
672ifdef need-config
673ifdef may-sync-config
674# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
675# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
676# because some architectures define CROSS_COMPILE there.
677include include/config/auto.conf.cmd
678
679$(KCONFIG_CONFIG):
680	@echo >&2 '***'
681	@echo >&2 '*** Configuration file "$@" not found!'
682	@echo >&2 '***'
683	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
684	@echo >&2 '*** "make menuconfig" or "make xconfig").'
685	@echo >&2 '***'
686	@/bin/false
687
688# The actual configuration files used during the build are stored in
689# include/generated/ and include/config/. Update them if .config is newer than
690# include/config/auto.conf (which mirrors .config).
691#
692# This exploits the 'multi-target pattern rule' trick.
693# The syncconfig should be executed only once to make all the targets.
694%/auto.conf %/auto.conf.cmd %/tristate.conf: $(KCONFIG_CONFIG)
695	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
696else # !may-sync-config
697# External modules and some install targets need include/generated/autoconf.h
698# and include/config/auto.conf but do not care if they are up-to-date.
699# Use auto.conf to trigger the test
700PHONY += include/config/auto.conf
701
702include/config/auto.conf:
703	$(Q)test -e include/generated/autoconf.h -a -e $@ || (		\
704	echo >&2;							\
705	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
706	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
707	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
708	echo >&2 ;							\
709	/bin/false)
710
711endif # may-sync-config
712endif # need-config
713
714KBUILD_CFLAGS	+= $(call cc-option,-fno-delete-null-pointer-checks,)
715KBUILD_CFLAGS	+= $(call cc-disable-warning,frame-address,)
716KBUILD_CFLAGS	+= $(call cc-disable-warning, format-truncation)
717KBUILD_CFLAGS	+= $(call cc-disable-warning, format-overflow)
718KBUILD_CFLAGS	+= $(call cc-disable-warning, address-of-packed-member)
719
720ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
721KBUILD_CFLAGS += -O2
722else ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3
723KBUILD_CFLAGS += -O3
724else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
725KBUILD_CFLAGS += -Os
726endif
727
728ifdef CONFIG_CC_DISABLE_WARN_MAYBE_UNINITIALIZED
729KBUILD_CFLAGS   += -Wno-maybe-uninitialized
730endif
731
732# Tell gcc to never replace conditional load with a non-conditional one
733KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
734
735include scripts/Makefile.kcov
736include scripts/Makefile.gcc-plugins
737
738ifdef CONFIG_READABLE_ASM
739# Disable optimizations that make assembler listings hard to read.
740# reorder blocks reorders the control in the function
741# ipa clone creates specialized cloned functions
742# partial inlining inlines only parts of functions
743KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
744                 $(call cc-option,-fno-ipa-cp-clone,) \
745                 $(call cc-option,-fno-partial-inlining)
746endif
747
748ifneq ($(CONFIG_FRAME_WARN),0)
749KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
750endif
751
752stackp-flags-$(CONFIG_CC_HAS_STACKPROTECTOR_NONE) := -fno-stack-protector
753stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
754stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
755
756KBUILD_CFLAGS += $(stackp-flags-y)
757
758ifdef CONFIG_CC_IS_CLANG
759KBUILD_CPPFLAGS += -Qunused-arguments
760KBUILD_CFLAGS += -Wno-format-invalid-specifier
761KBUILD_CFLAGS += -Wno-gnu
762# Quiet clang warning: comparison of unsigned expression < 0 is always false
763KBUILD_CFLAGS += -Wno-tautological-compare
764# CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
765# source of a reference will be _MergedGlobals and not on of the whitelisted names.
766# See modpost pattern 2
767KBUILD_CFLAGS += -mno-global-merge
768else
769
770# These warnings generated too much noise in a regular build.
771# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
772KBUILD_CFLAGS += -Wno-unused-but-set-variable
773
774# Warn about unmarked fall-throughs in switch statement.
775# Disabled for clang while comment to attribute conversion happens and
776# https://github.com/ClangBuiltLinux/linux/issues/636 is discussed.
777KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough,)
778endif
779
780KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
781ifdef CONFIG_FRAME_POINTER
782KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
783else
784# Some targets (ARM with Thumb2, for example), can't be built with frame
785# pointers.  For those, we don't have FUNCTION_TRACER automatically
786# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
787# incompatible with -fomit-frame-pointer with current GCC, so we don't use
788# -fomit-frame-pointer with FUNCTION_TRACER.
789ifndef CONFIG_FUNCTION_TRACER
790KBUILD_CFLAGS	+= -fomit-frame-pointer
791endif
792endif
793
794# Initialize all stack variables with a pattern, if desired.
795ifdef CONFIG_INIT_STACK_ALL
796KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
797endif
798
799DEBUG_CFLAGS	:= $(call cc-option, -fno-var-tracking-assignments)
800
801ifdef CONFIG_DEBUG_INFO
802ifdef CONFIG_DEBUG_INFO_SPLIT
803DEBUG_CFLAGS	+= -gsplit-dwarf
804else
805DEBUG_CFLAGS	+= -g
806endif
807KBUILD_AFLAGS	+= -Wa,-gdwarf-2
808endif
809ifdef CONFIG_DEBUG_INFO_DWARF4
810DEBUG_CFLAGS	+= -gdwarf-4
811endif
812
813ifdef CONFIG_DEBUG_INFO_REDUCED
814DEBUG_CFLAGS	+= $(call cc-option, -femit-struct-debug-baseonly) \
815		   $(call cc-option,-fno-var-tracking)
816endif
817
818KBUILD_CFLAGS += $(DEBUG_CFLAGS)
819export DEBUG_CFLAGS
820
821ifdef CONFIG_FUNCTION_TRACER
822ifdef CONFIG_FTRACE_MCOUNT_RECORD
823  # gcc 5 supports generating the mcount tables directly
824  ifeq ($(call cc-option-yn,-mrecord-mcount),y)
825    CC_FLAGS_FTRACE	+= -mrecord-mcount
826    export CC_USING_RECORD_MCOUNT := 1
827  endif
828  ifdef CONFIG_HAVE_NOP_MCOUNT
829    ifeq ($(call cc-option-yn, -mnop-mcount),y)
830      CC_FLAGS_FTRACE	+= -mnop-mcount
831      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
832    endif
833  endif
834endif
835ifdef CONFIG_HAVE_FENTRY
836  ifeq ($(call cc-option-yn, -mfentry),y)
837    CC_FLAGS_FTRACE	+= -mfentry
838    CC_FLAGS_USING	+= -DCC_USING_FENTRY
839  endif
840endif
841export CC_FLAGS_FTRACE
842KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
843KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
844ifdef CONFIG_DYNAMIC_FTRACE
845	ifdef CONFIG_HAVE_C_RECORDMCOUNT
846		BUILD_C_RECORDMCOUNT := y
847		export BUILD_C_RECORDMCOUNT
848	endif
849endif
850endif
851
852# We trigger additional mismatches with less inlining
853ifdef CONFIG_DEBUG_SECTION_MISMATCH
854KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
855endif
856
857ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
858KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
859LDFLAGS_vmlinux += --gc-sections
860endif
861
862ifdef CONFIG_LIVEPATCH
863KBUILD_CFLAGS += $(call cc-option, -flive-patching=inline-clone)
864endif
865
866# arch Makefile may override CC so keep this after arch Makefile is included
867NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
868
869# warn about C99 declaration after statement
870KBUILD_CFLAGS += -Wdeclaration-after-statement
871
872# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
873KBUILD_CFLAGS += -Wvla
874
875# disable pointer signed / unsigned warnings in gcc 4.0
876KBUILD_CFLAGS += -Wno-pointer-sign
877
878# disable stringop warnings in gcc 8+
879KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
880
881# disable invalid "can't wrap" optimizations for signed / pointers
882KBUILD_CFLAGS	+= $(call cc-option,-fno-strict-overflow)
883
884# clang sets -fmerge-all-constants by default as optimization, but this
885# is non-conforming behavior for C and in fact breaks the kernel, so we
886# need to disable it here generally.
887KBUILD_CFLAGS	+= $(call cc-option,-fno-merge-all-constants)
888
889# for gcc -fno-merge-all-constants disables everything, but it is fine
890# to have actual conforming behavior enabled.
891KBUILD_CFLAGS	+= $(call cc-option,-fmerge-constants)
892
893# Make sure -fstack-check isn't enabled (like gentoo apparently did)
894KBUILD_CFLAGS  += $(call cc-option,-fno-stack-check,)
895
896# conserve stack if available
897KBUILD_CFLAGS   += $(call cc-option,-fconserve-stack)
898
899# Prohibit date/time macros, which would make the build non-deterministic
900KBUILD_CFLAGS   += $(call cc-option,-Werror=date-time)
901
902# enforce correct pointer usage
903KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
904
905# Require designated initializers for all marked structures
906KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
907
908# change __FILE__ to the relative path from the srctree
909KBUILD_CFLAGS	+= $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
910
911# ensure -fcf-protection is disabled when using retpoline as it is
912# incompatible with -mindirect-branch=thunk-extern
913ifdef CONFIG_RETPOLINE
914KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none)
915endif
916
917# use the deterministic mode of AR if available
918KBUILD_ARFLAGS := $(call ar-option,D)
919
920include scripts/Makefile.kasan
921include scripts/Makefile.extrawarn
922include scripts/Makefile.ubsan
923
924# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
925KBUILD_CPPFLAGS += $(KCPPFLAGS)
926KBUILD_AFLAGS   += $(KAFLAGS)
927KBUILD_CFLAGS   += $(KCFLAGS)
928
929KBUILD_LDFLAGS_MODULE += --build-id
930LDFLAGS_vmlinux += --build-id
931
932ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
933LDFLAGS_vmlinux	+= $(call ld-option, -X,)
934endif
935
936ifeq ($(CONFIG_RELR),y)
937LDFLAGS_vmlinux	+= --pack-dyn-relocs=relr
938endif
939
940# insure the checker run with the right endianness
941CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
942
943# the checker needs the correct machine size
944CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
945
946# Default kernel image to build when no specific target is given.
947# KBUILD_IMAGE may be overruled on the command line or
948# set in the environment
949# Also any assignments in arch/$(ARCH)/Makefile take precedence over
950# this default value
951export KBUILD_IMAGE ?= vmlinux
952
953#
954# INSTALL_PATH specifies where to place the updated kernel and system map
955# images. Default is /boot, but you can set it to other values
956export	INSTALL_PATH ?= /boot
957
958#
959# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
960# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
961# an argument if needed. Otherwise it defaults to the kernel install path
962#
963export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
964
965#
966# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
967# relocations required by build roots.  This is not defined in the
968# makefile but the argument can be passed to make if needed.
969#
970
971MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
972export MODLIB
973
974#
975# INSTALL_MOD_STRIP, if defined, will cause modules to be
976# stripped after they are installed.  If INSTALL_MOD_STRIP is '1', then
977# the default option --strip-debug will be used.  Otherwise,
978# INSTALL_MOD_STRIP value will be used as the options to the strip command.
979
980ifdef INSTALL_MOD_STRIP
981ifeq ($(INSTALL_MOD_STRIP),1)
982mod_strip_cmd = $(STRIP) --strip-debug
983else
984mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
985endif # INSTALL_MOD_STRIP=1
986else
987mod_strip_cmd = true
988endif # INSTALL_MOD_STRIP
989export mod_strip_cmd
990
991# CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
992# after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
993# or CONFIG_MODULE_COMPRESS_XZ.
994
995mod_compress_cmd = true
996ifdef CONFIG_MODULE_COMPRESS
997  ifdef CONFIG_MODULE_COMPRESS_GZIP
998    mod_compress_cmd = gzip -n -f
999  endif # CONFIG_MODULE_COMPRESS_GZIP
1000  ifdef CONFIG_MODULE_COMPRESS_XZ
1001    mod_compress_cmd = xz -f
1002  endif # CONFIG_MODULE_COMPRESS_XZ
1003endif # CONFIG_MODULE_COMPRESS
1004export mod_compress_cmd
1005
1006ifdef CONFIG_MODULE_SIG_ALL
1007$(eval $(call config_filename,MODULE_SIG_KEY))
1008
1009mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
1010else
1011mod_sign_cmd = true
1012endif
1013export mod_sign_cmd
1014
1015HOST_LIBELF_LIBS = $(shell pkg-config libelf --libs 2>/dev/null || echo -lelf)
1016
1017ifdef CONFIG_STACK_VALIDATION
1018  has_libelf := $(call try-run,\
1019		echo "int main() {}" | $(HOSTCC) -xc -o /dev/null $(HOST_LIBELF_LIBS) -,1,0)
1020  ifeq ($(has_libelf),1)
1021    objtool_target := tools/objtool FORCE
1022  else
1023    SKIP_STACK_VALIDATION := 1
1024    export SKIP_STACK_VALIDATION
1025  endif
1026endif
1027
1028PHONY += prepare0
1029
1030export MODORDER := $(extmod-prefix)modules.order
1031
1032ifeq ($(KBUILD_EXTMOD),)
1033core-y		+= kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
1034
1035vmlinux-dirs	:= $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
1036		     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1037		     $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
1038
1039vmlinux-alldirs	:= $(sort $(vmlinux-dirs) Documentation \
1040		     $(patsubst %/,%,$(filter %/, $(init-) $(core-) \
1041			$(drivers-) $(net-) $(libs-) $(virt-))))
1042
1043build-dirs	:= $(vmlinux-dirs)
1044clean-dirs	:= $(vmlinux-alldirs)
1045
1046init-y		:= $(patsubst %/, %/built-in.a, $(init-y))
1047core-y		:= $(patsubst %/, %/built-in.a, $(core-y))
1048drivers-y	:= $(patsubst %/, %/built-in.a, $(drivers-y))
1049net-y		:= $(patsubst %/, %/built-in.a, $(net-y))
1050libs-y1		:= $(patsubst %/, %/lib.a, $(libs-y))
1051libs-y2		:= $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y)))
1052virt-y		:= $(patsubst %/, %/built-in.a, $(virt-y))
1053
1054# Externally visible symbols (used by link-vmlinux.sh)
1055export KBUILD_VMLINUX_OBJS := $(head-y) $(init-y) $(core-y) $(libs-y2) \
1056			      $(drivers-y) $(net-y) $(virt-y)
1057export KBUILD_VMLINUX_LIBS := $(libs-y1)
1058export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1059export LDFLAGS_vmlinux
1060# used by scripts/package/Makefile
1061export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1062
1063vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1064
1065# Recurse until adjust_autoksyms.sh is satisfied
1066PHONY += autoksyms_recursive
1067ifdef CONFIG_TRIM_UNUSED_KSYMS
1068autoksyms_recursive: descend modules.order
1069	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1070	  "$(MAKE) -f $(srctree)/Makefile vmlinux"
1071endif
1072
1073# For the kernel to actually contain only the needed exported symbols,
1074# we have to build modules as well to determine what those symbols are.
1075# (this can be evaluated only once include/config/auto.conf has been included)
1076ifdef CONFIG_TRIM_UNUSED_KSYMS
1077  KBUILD_MODULES := 1
1078endif
1079
1080autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1081
1082$(autoksyms_h):
1083	$(Q)mkdir -p $(dir $@)
1084	$(Q)touch $@
1085
1086ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1087
1088# Final link of vmlinux with optional arch pass after final link
1089cmd_link-vmlinux =                                                 \
1090	$(CONFIG_SHELL) $< $(LD) $(KBUILD_LDFLAGS) $(LDFLAGS_vmlinux) ;    \
1091	$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1092
1093vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1094	+$(call if_changed,link-vmlinux)
1095
1096targets := vmlinux
1097
1098# The actual objects are generated when descending,
1099# make sure no implicit rule kicks in
1100$(sort $(vmlinux-deps)): descend ;
1101
1102filechk_kernel.release = \
1103	echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1104
1105# Store (new) KERNELRELEASE string in include/config/kernel.release
1106include/config/kernel.release: FORCE
1107	$(call filechk,kernel.release)
1108
1109# Additional helpers built in scripts/
1110# Carefully list dependencies so we do not try to build scripts twice
1111# in parallel
1112PHONY += scripts
1113scripts: scripts_basic scripts_dtc
1114	$(Q)$(MAKE) $(build)=$(@)
1115
1116# Things we need to do before we recursively start building the kernel
1117# or the modules are listed in "prepare".
1118# A multi level approach is used. prepareN is processed before prepareN-1.
1119# archprepare is used in arch Makefiles and when processed asm symlink,
1120# version.h and scripts_basic is processed / created.
1121
1122PHONY += prepare archprepare
1123
1124archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1125	asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h
1126
1127prepare0: archprepare
1128	$(Q)$(MAKE) $(build)=scripts/mod
1129	$(Q)$(MAKE) $(build)=.
1130
1131# All the preparing..
1132prepare: prepare0 prepare-objtool
1133
1134# Support for using generic headers in asm-generic
1135asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1136
1137PHONY += asm-generic uapi-asm-generic
1138asm-generic: uapi-asm-generic
1139	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1140	generic=include/asm-generic
1141uapi-asm-generic:
1142	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1143	generic=include/uapi/asm-generic
1144
1145PHONY += prepare-objtool
1146prepare-objtool: $(objtool_target)
1147ifeq ($(SKIP_STACK_VALIDATION),1)
1148ifdef CONFIG_UNWINDER_ORC
1149	@echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1150	@false
1151else
1152	@echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1153endif
1154endif
1155
1156# Generate some files
1157# ---------------------------------------------------------------------------
1158
1159# KERNELRELEASE can change from a few different places, meaning version.h
1160# needs to be updated, so this check is forced on all builds
1161
1162uts_len := 64
1163define filechk_utsrelease.h
1164	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1165	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1166	  exit 1;                                                         \
1167	fi;                                                               \
1168	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1169endef
1170
1171define filechk_version.h
1172	echo \#define LINUX_VERSION_CODE $(shell                         \
1173	expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
1174	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))'
1175endef
1176
1177$(version_h): FORCE
1178	$(call filechk,version.h)
1179	$(Q)rm -f $(old_version_h)
1180
1181include/generated/utsrelease.h: include/config/kernel.release FORCE
1182	$(call filechk,utsrelease.h)
1183
1184PHONY += headerdep
1185headerdep:
1186	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1187	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1188
1189# ---------------------------------------------------------------------------
1190# Kernel headers
1191
1192#Default location for installed headers
1193export INSTALL_HDR_PATH = $(objtree)/usr
1194
1195quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1196      cmd_headers_install = \
1197	mkdir -p $(INSTALL_HDR_PATH); \
1198	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1199	usr/include $(INSTALL_HDR_PATH)
1200
1201PHONY += headers_install
1202headers_install: headers
1203	$(call cmd,headers_install)
1204
1205PHONY += archheaders archscripts
1206
1207hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1208
1209PHONY += headers
1210headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1211	$(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1212	  $(error Headers not exportable for the $(SRCARCH) architecture))
1213	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1214	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1215
1216PHONY += headers_check
1217headers_check: headers
1218	$(Q)$(MAKE) $(hdr-inst)=include/uapi HDRCHECK=1
1219	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi HDRCHECK=1
1220
1221ifdef CONFIG_HEADERS_INSTALL
1222prepare: headers
1223endif
1224
1225ifdef CONFIG_HEADERS_CHECK
1226all: headers_check
1227endif
1228
1229PHONY += scripts_unifdef
1230scripts_unifdef: scripts_basic
1231	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1232
1233# ---------------------------------------------------------------------------
1234# Kernel selftest
1235
1236PHONY += kselftest
1237kselftest:
1238	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1239
1240PHONY += kselftest-clean
1241kselftest-clean:
1242	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests clean
1243
1244PHONY += kselftest-merge
1245kselftest-merge:
1246	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1247	$(Q)find $(srctree)/tools/testing/selftests -name config | \
1248		xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1249	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1250
1251# ---------------------------------------------------------------------------
1252# Devicetree files
1253
1254ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1255dtstree := arch/$(SRCARCH)/boot/dts
1256endif
1257
1258ifneq ($(dtstree),)
1259
1260%.dtb: include/config/kernel.release scripts_dtc
1261	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1262
1263PHONY += dtbs dtbs_install dt_binding_check
1264dtbs dtbs_check: include/config/kernel.release scripts_dtc
1265	$(Q)$(MAKE) $(build)=$(dtstree)
1266
1267dtbs_check: export CHECK_DTBS=1
1268dtbs_check: dt_binding_check
1269
1270dtbs_install:
1271	$(Q)$(MAKE) $(dtbinst)=$(dtstree)
1272
1273ifdef CONFIG_OF_EARLY_FLATTREE
1274all: dtbs
1275endif
1276
1277endif
1278
1279PHONY += scripts_dtc
1280scripts_dtc: scripts_basic
1281	$(Q)$(MAKE) $(build)=scripts/dtc
1282
1283dt_binding_check: scripts_dtc
1284	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1285
1286# ---------------------------------------------------------------------------
1287# Modules
1288
1289ifdef CONFIG_MODULES
1290
1291# By default, build modules as well
1292
1293all: modules
1294
1295# Build modules
1296#
1297# A module can be listed more than once in obj-m resulting in
1298# duplicate lines in modules.order files.  Those are removed
1299# using awk while concatenating to the final file.
1300
1301PHONY += modules
1302modules: $(if $(KBUILD_BUILTIN),vmlinux) modules.order modules.builtin
1303	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1304	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh
1305
1306modules.order: descend
1307	$(Q)$(AWK) '!x[$$0]++' $(addsuffix /$@, $(build-dirs)) > $@
1308
1309modbuiltin-dirs := $(addprefix _modbuiltin_, $(build-dirs))
1310
1311modules.builtin: $(modbuiltin-dirs)
1312	$(Q)$(AWK) '!x[$$0]++' $(addsuffix /$@, $(build-dirs)) > $@
1313
1314PHONY += $(modbuiltin-dirs)
1315# tristate.conf is not included from this Makefile. Add it as a prerequisite
1316# here to make it self-healing in case somebody accidentally removes it.
1317$(modbuiltin-dirs): include/config/tristate.conf
1318	$(Q)$(MAKE) $(modbuiltin)=$(patsubst _modbuiltin_%,%,$@)
1319
1320# Target to prepare building external modules
1321PHONY += modules_prepare
1322modules_prepare: prepare
1323
1324# Target to install modules
1325PHONY += modules_install
1326modules_install: _modinst_ _modinst_post
1327
1328PHONY += _modinst_
1329_modinst_:
1330	@rm -rf $(MODLIB)/kernel
1331	@rm -f $(MODLIB)/source
1332	@mkdir -p $(MODLIB)/kernel
1333	@ln -s $(abspath $(srctree)) $(MODLIB)/source
1334	@if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1335		rm -f $(MODLIB)/build ; \
1336		ln -s $(CURDIR) $(MODLIB)/build ; \
1337	fi
1338	@sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1339	@sed 's:^:kernel/:' modules.builtin > $(MODLIB)/modules.builtin
1340	@cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1341	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1342
1343# This depmod is only for convenience to give the initial
1344# boot a modules.dep even before / is mounted read-write.  However the
1345# boot script depmod is the master version.
1346PHONY += _modinst_post
1347_modinst_post: _modinst_
1348	$(call cmd,depmod)
1349
1350ifeq ($(CONFIG_MODULE_SIG), y)
1351PHONY += modules_sign
1352modules_sign:
1353	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1354endif
1355
1356else # CONFIG_MODULES
1357
1358# Modules not configured
1359# ---------------------------------------------------------------------------
1360
1361PHONY += modules modules_install
1362modules modules_install:
1363	@echo >&2
1364	@echo >&2 "The present kernel configuration has modules disabled."
1365	@echo >&2 "Type 'make config' and enable loadable module support."
1366	@echo >&2 "Then build a kernel with module support enabled."
1367	@echo >&2
1368	@exit 1
1369
1370endif # CONFIG_MODULES
1371
1372###
1373# Cleaning is done on three levels.
1374# make clean     Delete most generated files
1375#                Leave enough to build external modules
1376# make mrproper  Delete the current configuration, and all generated files
1377# make distclean Remove editor backup files, patch leftover files and the like
1378
1379# Directories & files removed with 'make clean'
1380CLEAN_DIRS  += include/ksym
1381CLEAN_FILES += modules.builtin.modinfo
1382
1383# Directories & files removed with 'make mrproper'
1384MRPROPER_DIRS  += include/config include/generated          \
1385		  arch/$(SRCARCH)/include/generated .tmp_objdiff \
1386		  debian/ snap/ tar-install/
1387MRPROPER_FILES += .config .config.old .version \
1388		  Module.symvers \
1389		  signing_key.pem signing_key.priv signing_key.x509	\
1390		  x509.genkey extra_certificates signing_key.x509.keyid	\
1391		  signing_key.x509.signer vmlinux-gdb.py \
1392		  *.spec
1393
1394# Directories & files removed with 'make distclean'
1395DISTCLEAN_DIRS  +=
1396DISTCLEAN_FILES += tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS
1397
1398# clean - Delete most, but leave enough to build external modules
1399#
1400clean: rm-dirs  := $(CLEAN_DIRS)
1401clean: rm-files := $(CLEAN_FILES)
1402
1403PHONY += archclean vmlinuxclean
1404
1405vmlinuxclean:
1406	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1407	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1408
1409clean: archclean vmlinuxclean
1410
1411# mrproper - Delete all generated files, including .config
1412#
1413mrproper: rm-dirs  := $(wildcard $(MRPROPER_DIRS))
1414mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1415mrproper-dirs      := $(addprefix _mrproper_,scripts)
1416
1417PHONY += $(mrproper-dirs) mrproper
1418$(mrproper-dirs):
1419	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1420
1421mrproper: clean $(mrproper-dirs)
1422	$(call cmd,rmdirs)
1423	$(call cmd,rmfiles)
1424
1425# distclean
1426#
1427distclean: rm-dirs  := $(wildcard $(DISTCLEAN_DIRS))
1428distclean: rm-files := $(wildcard $(DISTCLEAN_FILES))
1429
1430PHONY += distclean
1431
1432distclean: mrproper
1433	$(call cmd,rmdirs)
1434	$(call cmd,rmfiles)
1435	@find $(srctree) $(RCS_FIND_IGNORE) \
1436		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1437		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1438		-o -name 'core' \) \
1439		-type f -print | xargs rm -f
1440
1441
1442# Packaging of the kernel to various formats
1443# ---------------------------------------------------------------------------
1444
1445%src-pkg: FORCE
1446	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1447%pkg: include/config/kernel.release FORCE
1448	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1449
1450# Brief documentation of the typical targets used
1451# ---------------------------------------------------------------------------
1452
1453boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1454boards := $(sort $(notdir $(boards)))
1455board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1456board-dirs := $(sort $(notdir $(board-dirs:/=)))
1457
1458PHONY += help
1459help:
1460	@echo  'Cleaning targets:'
1461	@echo  '  clean		  - Remove most generated files but keep the config and'
1462	@echo  '                    enough build support to build external modules'
1463	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1464	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1465	@echo  ''
1466	@echo  'Configuration targets:'
1467	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1468	@echo  ''
1469	@echo  'Other generic targets:'
1470	@echo  '  all		  - Build all targets marked with [*]'
1471	@echo  '* vmlinux	  - Build the bare kernel'
1472	@echo  '* modules	  - Build all modules'
1473	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1474	@echo  '  dir/            - Build all files in dir and below'
1475	@echo  '  dir/file.[ois]  - Build specified target only'
1476	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1477	@echo  '                    (requires compiler support for LLVM assembly generation)'
1478	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1479	@echo  '                    (requires a recent binutils and recent build (System.map))'
1480	@echo  '  dir/file.ko     - Build module including final link'
1481	@echo  '  modules_prepare - Set up for building external modules'
1482	@echo  '  tags/TAGS	  - Generate tags file for editors'
1483	@echo  '  cscope	  - Generate cscope index'
1484	@echo  '  gtags           - Generate GNU GLOBAL index'
1485	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1486	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1487	@echo  '  image_name	  - Output the image name (use with make -s)'
1488	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1489	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1490	 echo  ''
1491	@echo  'Static analysers:'
1492	@echo  '  checkstack      - Generate a list of stack hogs'
1493	@echo  '  namespacecheck  - Name space analysis on compiled kernel'
1494	@echo  '  versioncheck    - Sanity check on version.h usage'
1495	@echo  '  includecheck    - Check for duplicate included header files'
1496	@echo  '  export_report   - List the usages of all exported symbols'
1497	@echo  '  headers_check   - Sanity check on exported headers'
1498	@echo  '  headerdep       - Detect inclusion cycles in headers'
1499	@echo  '  coccicheck      - Check with Coccinelle'
1500	@echo  ''
1501	@echo  'Tools:'
1502	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1503	@echo  ''
1504	@echo  'Kernel selftest:'
1505	@echo  '  kselftest       - Build and run kernel selftest (run as root)'
1506	@echo  '                    Build, install, and boot kernel before'
1507	@echo  '                    running kselftest on it'
1508	@echo  '  kselftest-clean - Remove all generated kselftest files'
1509	@echo  '  kselftest-merge - Merge all the config dependencies of kselftest to existing'
1510	@echo  '                    .config.'
1511	@echo  ''
1512	@$(if $(dtstree), \
1513		echo 'Devicetree:'; \
1514		echo '* dtbs             - Build device tree blobs for enabled boards'; \
1515		echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1516		echo '  dt_binding_check - Validate device tree binding documents'; \
1517		echo '  dtbs_check       - Validate device tree source files';\
1518		echo '')
1519
1520	@echo 'Userspace tools targets:'
1521	@echo '  use "make tools/help"'
1522	@echo '  or  "cd tools; make help"'
1523	@echo  ''
1524	@echo  'Kernel packaging:'
1525	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1526	@echo  ''
1527	@echo  'Documentation targets:'
1528	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1529	@echo  ''
1530	@echo  'Architecture specific targets ($(SRCARCH)):'
1531	@$(if $(archhelp),$(archhelp),\
1532		echo '  No architecture specific help defined for $(SRCARCH)')
1533	@echo  ''
1534	@$(if $(boards), \
1535		$(foreach b, $(boards), \
1536		printf "  %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1537		echo '')
1538	@$(if $(board-dirs), \
1539		$(foreach b, $(board-dirs), \
1540		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1541		printf "  %-16s - Show all of the above\\n" help-boards; \
1542		echo '')
1543
1544	@echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1545	@echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1546	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1547	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK (sparse by default)'
1548	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1549	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1550	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1551	@echo  '		1: warnings which may be relevant and do not occur too often'
1552	@echo  '		2: warnings which occur quite often but may still be relevant'
1553	@echo  '		3: more obscure warnings, can most likely be ignored'
1554	@echo  '		Multiple levels can be combined with W=12 or W=123'
1555	@echo  ''
1556	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1557	@echo  'For further info see the ./README file'
1558
1559
1560help-board-dirs := $(addprefix help-,$(board-dirs))
1561
1562help-boards: $(help-board-dirs)
1563
1564boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1565
1566$(help-board-dirs): help-%:
1567	@echo  'Architecture specific targets ($(SRCARCH) $*):'
1568	@$(if $(boards-per-dir), \
1569		$(foreach b, $(boards-per-dir), \
1570		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1571		echo '')
1572
1573
1574# Documentation targets
1575# ---------------------------------------------------------------------------
1576DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1577	       linkcheckdocs dochelp refcheckdocs
1578PHONY += $(DOC_TARGETS)
1579$(DOC_TARGETS):
1580	$(Q)$(MAKE) $(build)=Documentation $@
1581
1582# Misc
1583# ---------------------------------------------------------------------------
1584
1585PHONY += scripts_gdb
1586scripts_gdb: prepare0
1587	$(Q)$(MAKE) $(build)=scripts/gdb
1588	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1589
1590ifdef CONFIG_GDB_SCRIPTS
1591all: scripts_gdb
1592endif
1593
1594else # KBUILD_EXTMOD
1595
1596###
1597# External module support.
1598# When building external modules the kernel used as basis is considered
1599# read-only, and no consistency checks are made and the make
1600# system is not used on the basis kernel. If updates are required
1601# in the basis kernel ordinary make commands (without M=...) must
1602# be used.
1603#
1604# The following are the only valid targets when building external
1605# modules.
1606# make M=dir clean     Delete all automatically generated files
1607# make M=dir modules   Make all modules in specified dir
1608# make M=dir	       Same as 'make M=dir modules'
1609# make M=dir modules_install
1610#                      Install the modules built in the module directory
1611#                      Assumes install directory is already created
1612
1613# We are always building modules
1614KBUILD_MODULES := 1
1615
1616PHONY += $(objtree)/Module.symvers
1617$(objtree)/Module.symvers:
1618	@test -e $(objtree)/Module.symvers || ( \
1619	echo; \
1620	echo "  WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1621	echo "           is missing; modules will have no dependencies and modversions."; \
1622	echo )
1623
1624build-dirs := $(KBUILD_EXTMOD)
1625PHONY += modules
1626modules: descend $(objtree)/Module.symvers
1627	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1628
1629PHONY += modules_install
1630modules_install: _emodinst_ _emodinst_post
1631
1632install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1633PHONY += _emodinst_
1634_emodinst_:
1635	$(Q)mkdir -p $(MODLIB)/$(install-dir)
1636	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1637
1638PHONY += _emodinst_post
1639_emodinst_post: _emodinst_
1640	$(call cmd,depmod)
1641
1642clean-dirs := $(KBUILD_EXTMOD)
1643clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1644
1645PHONY += /
1646/:
1647	@echo >&2 '"$(MAKE) /" is no longer supported. Please use "$(MAKE) ./" instead.'
1648
1649PHONY += help
1650help:
1651	@echo  '  Building external modules.'
1652	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1653	@echo  ''
1654	@echo  '  modules         - default target, build the module(s)'
1655	@echo  '  modules_install - install the module'
1656	@echo  '  clean           - remove generated files in module directory only'
1657	@echo  ''
1658
1659PHONY += prepare
1660endif # KBUILD_EXTMOD
1661
1662# Handle descending into subdirectories listed in $(build-dirs)
1663# Preset locale variables to speed up the build process. Limit locale
1664# tweaks to this spot to avoid wrong language settings when running
1665# make menuconfig etc.
1666# Error messages still appears in the original language
1667PHONY += descend $(build-dirs)
1668descend: $(build-dirs)
1669$(build-dirs): prepare
1670	$(Q)$(MAKE) $(build)=$@ single-build=$(single-build) need-builtin=1 need-modorder=1
1671
1672clean-dirs := $(addprefix _clean_, $(clean-dirs))
1673PHONY += $(clean-dirs) clean
1674$(clean-dirs):
1675	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1676
1677clean: $(clean-dirs)
1678	$(call cmd,rmdirs)
1679	$(call cmd,rmfiles)
1680	@find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1681		\( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1682		-o -name '*.ko.*' \
1683		-o -name '*.dtb' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1684		-o -name '*.dwo' -o -name '*.lst' \
1685		-o -name '*.su' -o -name '*.mod' -o -name '*.ns_deps' \
1686		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1687		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
1688		-o -name '*.asn1.[ch]' \
1689		-o -name '*.symtypes' -o -name 'modules.order' \
1690		-o -name modules.builtin -o -name '.tmp_*.o.*' \
1691		-o -name '*.c.[012]*.*' \
1692		-o -name '*.ll' \
1693		-o -name '*.gcno' \) -type f -print | xargs rm -f
1694
1695# Generate tags for editors
1696# ---------------------------------------------------------------------------
1697quiet_cmd_tags = GEN     $@
1698      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1699
1700tags TAGS cscope gtags: FORCE
1701	$(call cmd,tags)
1702
1703# Script to generate missing namespace dependencies
1704# ---------------------------------------------------------------------------
1705
1706PHONY += nsdeps
1707
1708nsdeps: modules
1709	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost nsdeps
1710	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1711
1712# Scripts to check various things for consistency
1713# ---------------------------------------------------------------------------
1714
1715PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1716
1717includecheck:
1718	find $(srctree)/* $(RCS_FIND_IGNORE) \
1719		-name '*.[hcS]' -type f -print | sort \
1720		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1721
1722versioncheck:
1723	find $(srctree)/* $(RCS_FIND_IGNORE) \
1724		-name '*.[hcS]' -type f -print | sort \
1725		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1726
1727coccicheck:
1728	$(Q)$(BASH) $(srctree)/scripts/$@
1729
1730namespacecheck:
1731	$(PERL) $(srctree)/scripts/namespace.pl
1732
1733export_report:
1734	$(PERL) $(srctree)/scripts/export_report.pl
1735
1736PHONY += checkstack kernelrelease kernelversion image_name
1737
1738# UML needs a little special treatment here.  It wants to use the host
1739# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
1740# else wants $(ARCH), including people doing cross-builds, which means
1741# that $(SUBARCH) doesn't work here.
1742ifeq ($(ARCH), um)
1743CHECKSTACK_ARCH := $(SUBARCH)
1744else
1745CHECKSTACK_ARCH := $(ARCH)
1746endif
1747checkstack:
1748	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1749	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1750
1751kernelrelease:
1752	@echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1753
1754kernelversion:
1755	@echo $(KERNELVERSION)
1756
1757image_name:
1758	@echo $(KBUILD_IMAGE)
1759
1760# Clear a bunch of variables before executing the submake
1761
1762ifeq ($(quiet),silent_)
1763tools_silent=s
1764endif
1765
1766tools/: FORCE
1767	$(Q)mkdir -p $(objtree)/tools
1768	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1769
1770tools/%: FORCE
1771	$(Q)mkdir -p $(objtree)/tools
1772	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1773
1774# Single targets
1775# ---------------------------------------------------------------------------
1776# To build individual files in subdirectories, you can do like this:
1777#
1778#   make foo/bar/baz.s
1779#
1780# The supported suffixes for single-target are listed in 'single-targets'
1781#
1782# To build only under specific subdirectories, you can do like this:
1783#
1784#   make foo/bar/baz/
1785
1786ifdef single-build
1787
1788single-all := $(filter $(single-targets), $(MAKECMDGOALS))
1789
1790# .ko is special because modpost is needed
1791single-ko := $(sort $(filter %.ko, $(single-all)))
1792single-no-ko := $(sort $(patsubst %.ko,%.mod, $(single-all)))
1793
1794$(single-ko): single_modpost
1795	@:
1796$(single-no-ko): descend
1797	@:
1798
1799ifeq ($(KBUILD_EXTMOD),)
1800# For the single build of in-tree modules, use a temporary file to avoid
1801# the situation of modules_install installing an invalid modules.order.
1802MODORDER := .modules.tmp
1803endif
1804
1805PHONY += single_modpost
1806single_modpost: $(single-no-ko)
1807	$(Q){ $(foreach m, $(single-ko), echo $(extmod-prefix)$m;) } > $(MODORDER)
1808	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1809
1810KBUILD_MODULES := 1
1811
1812export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod-prefix), $(single-no-ko))
1813
1814single-build = $(if $(filter-out $@/, $(single-no-ko)),1)
1815
1816endif
1817
1818# FIXME Should go into a make.lib or something
1819# ===========================================================================
1820
1821quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN   $(wildcard $(rm-dirs)))
1822      cmd_rmdirs = rm -rf $(rm-dirs)
1823
1824quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
1825      cmd_rmfiles = rm -f $(rm-files)
1826
1827# Run depmod only if we have System.map and depmod is executable
1828quiet_cmd_depmod = DEPMOD  $(KERNELRELEASE)
1829      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1830                   $(KERNELRELEASE)
1831
1832# read saved command lines for existing targets
1833existing-targets := $(wildcard $(sort $(targets)))
1834
1835-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1836
1837endif # config-targets
1838endif # mixed-build
1839endif # need-sub-make
1840
1841PHONY += FORCE
1842FORCE:
1843
1844# Declare the contents of the PHONY variable as phony.  We keep that
1845# information in a variable so we can use it in if_changed and friends.
1846.PHONY: $(PHONY)
1847