1 # SPDX-License-Identifier: GPL-2.0
2 # Backward compatibility
3 asflags-y += $(EXTRA_AFLAGS)
4 ccflags-y += $(EXTRA_CFLAGS)
5 cppflags-y += $(EXTRA_CPPFLAGS)
6 ldflags-y += $(EXTRA_LDFLAGS)
8 # flags that take effect in current and sub directories
9 KBUILD_AFLAGS += $(subdir-asflags-y)
10 KBUILD_CFLAGS += $(subdir-ccflags-y)
12 # Figure out what we need to build from the various variables
13 # ===========================================================================
15 # When an object is listed to be built compiled-in and modular,
16 # only build the compiled-in version
17 obj-m := $(filter-out $(obj-y),$(obj-m))
19 # Libraries are always collected in one lib file.
20 # Filter out objects already built-in
21 lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m)))
23 # Subdirectories we need to descend into
24 subdir-ym := $(sort $(subdir-y) $(subdir-m) \
25 $(patsubst %/,%, $(filter %/, $(obj-y) $(obj-m))))
27 # Handle objects in subdirs:
28 # - If we encounter foo/ in $(obj-y), replace it by foo/built-in.a and
30 # - If we encounter foo/ in $(obj-m), replace it by foo/modules.order
32 # Generate modules.order to determine modorder. Unfortunately, we don't have
33 # information about ordering between -y and -m subdirs. Just put -y's first.
36 obj-m := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m))
38 obj-m := $(filter-out %/, $(obj-m))
42 obj-y := $(patsubst %/, %/built-in.a, $(obj-y))
44 obj-y := $(filter-out %/, $(obj-y))
47 # Expand $(foo-objs) $(foo-y) by calling $(call suffix-search,foo.o,-objs -y)
48 suffix-search = $(foreach s,$(2),$($(1:.o=$s)))
49 # If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object
50 multi-search = $(sort $(foreach m,$(1), $(if $(strip $(call suffix-search,$(m),$(2) -)), $(m))))
51 multi-used-y := $(call multi-search,$(obj-y),-objs -y)
52 multi-used-m := $(call multi-search,$(obj-m),-objs -y -m)
53 multi-used := $(multi-used-y) $(multi-used-m)
55 # Replace multi-part objects by their individual parts,
56 # including built-in.a from subdirectories
57 real-search = $(foreach m,$(1), $(if $(strip $(call suffix-search,$(m),$(2) -)),$(call suffix-search,$(m),$(2)),$(m)))
58 real-obj-y := $(call real-search, $(obj-y),-objs -y)
59 real-obj-m := $(call real-search, $(obj-m),-objs -y -m)
61 always-y += $(always-m)
63 # hostprogs-always-y += foo
64 # ... is a shorthand for
67 hostprogs += $(hostprogs-always-y) $(hostprogs-always-m)
68 always-y += $(hostprogs-always-y) $(hostprogs-always-m)
70 # userprogs-always-y is likewise.
71 userprogs += $(userprogs-always-y) $(userprogs-always-m)
72 always-y += $(userprogs-always-y) $(userprogs-always-m)
75 # If CONFIG_OF_ALL_DTBS is enabled, all DT blobs are built
77 always-$(CONFIG_OF_ALL_DTBS) += $(dtb-)
79 ifneq ($(CHECK_DTBS),)
80 always-y += $(patsubst %.dtb,%.dt.yaml, $(dtb-y))
81 always-$(CONFIG_OF_ALL_DTBS) += $(patsubst %.dtb,%.dt.yaml, $(dtb-))
86 extra-y := $(addprefix $(obj)/,$(extra-y))
87 always-y := $(addprefix $(obj)/,$(always-y))
88 targets := $(addprefix $(obj)/,$(targets))
89 obj-m := $(addprefix $(obj)/,$(obj-m))
90 lib-y := $(addprefix $(obj)/,$(lib-y))
91 real-obj-y := $(addprefix $(obj)/,$(real-obj-y))
92 real-obj-m := $(addprefix $(obj)/,$(real-obj-m))
93 multi-used-m := $(addprefix $(obj)/,$(multi-used-m))
94 subdir-ym := $(addprefix $(obj)/,$(subdir-ym))
96 # Finds the multi-part object the current object will be linked into.
97 # If the object belongs to two or more multi-part objects, list them all.
98 modname-multi = $(sort $(foreach m,$(multi-used),\
99 $(if $(filter $*.o, $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))),$(m:.o=))))
101 __modname = $(if $(modname-multi),$(modname-multi),$(basetarget))
103 modname = $(subst $(space),:,$(__modname))
104 modfile = $(addprefix $(obj)/,$(__modname))
106 # target with $(obj)/ and its suffix stripped
107 target-stem = $(basename $(patsubst $(obj)/%,%,$@))
109 # These flags are needed for modversions and compiling, so we define them here
110 # $(modname_flags) defines KBUILD_MODNAME as the name of the module it will
111 # end up in (or would, if it gets compiled in)
112 name-fix = $(call stringify,$(subst $(comma),_,$(subst -,_,$1)))
113 basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
114 modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname))
115 modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile))
117 _c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \
118 $(filter-out $(ccflags-remove-y), \
119 $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(ccflags-y)) \
120 $(CFLAGS_$(target-stem).o))
121 _a_flags = $(filter-out $(AFLAGS_REMOVE_$(target-stem).o), \
122 $(filter-out $(asflags-remove-y), \
123 $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(asflags-y)) \
124 $(AFLAGS_$(target-stem).o))
125 _cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(target-stem).lds)
128 # Enable gcov profiling flags for a file, directory or for all files depending
129 # on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL
132 ifeq ($(CONFIG_GCOV_KERNEL),y)
133 _c_flags += $(if $(patsubst n%,, \
134 $(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \
139 # Enable address sanitizer flags for kernel except some files or directories
140 # we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE)
142 ifeq ($(CONFIG_KASAN),y)
143 ifneq ($(CONFIG_KASAN_HW_TAGS),y)
144 _c_flags += $(if $(patsubst n%,, \
145 $(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \
146 $(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
150 ifeq ($(CONFIG_UBSAN),y)
151 _c_flags += $(if $(patsubst n%,, \
152 $(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
156 ifeq ($(CONFIG_KCOV),y)
157 _c_flags += $(if $(patsubst n%,, \
158 $(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \
163 # Enable KCSAN flags except some files or directories we don't want to check
164 # (depends on variables KCSAN_SANITIZE_obj.o, KCSAN_SANITIZE)
166 ifeq ($(CONFIG_KCSAN),y)
167 _c_flags += $(if $(patsubst n%,, \
168 $(KCSAN_SANITIZE_$(basetarget).o)$(KCSAN_SANITIZE)y), \
172 # $(srctree)/$(src) for including checkin headers from generated source files
173 # $(objtree)/$(obj) for including generated headers from checkin source files
174 ifeq ($(KBUILD_EXTMOD),)
175 ifdef building_out_of_srctree
176 _c_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
177 _a_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
178 _cpp_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
182 part-of-module = $(if $(filter $(basename $@).o, $(real-obj-m)),y)
183 quiet_modtag = $(if $(part-of-module),[M], )
186 $(if $(part-of-module), \
187 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
188 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL) $(modfile_flags))
190 modkern_aflags = $(if $(part-of-module), \
191 $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE), \
192 $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL))
194 c_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
195 -include $(srctree)/include/linux/compiler_types.h \
196 $(_c_flags) $(modkern_cflags) \
197 $(basename_flags) $(modname_flags)
199 a_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
200 $(_a_flags) $(modkern_aflags)
202 cpp_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
205 ld_flags = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F))
207 DTC_INCLUDE := $(srctree)/scripts/dtc/include-prefixes
209 dtc_cpp_flags = -Wp,-MMD,$(depfile).pre.tmp -nostdinc \
210 $(addprefix -I,$(DTC_INCLUDE)) \
213 # Useful for describing the dependency of composite objects
215 # $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
217 $(foreach m, $(notdir $1), \
219 $(addprefix $(obj)/, $(foreach s, $3, $($(m:%$(strip $2)=%$(s)))))))
222 quiet_cmd_copy = COPY $@
226 # ===========================================================================
228 quiet_cmd_shipped = SHIPPED $@
229 cmd_shipped = cat $< > $@
231 $(obj)/%: $(src)/%_shipped
234 # Commands useful for building a boot image
235 # ===========================================================================
239 # target: source(s) FORCE
240 # $(if_changed,ld/objcopy/gzip)
242 # and add target to 'targets' so that we know we have to
243 # read in the saved command line
246 # ---------------------------------------------------------------------------
249 cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@
252 # ---------------------------------------------------------------------------
255 cmd_ar = rm -f $@; $(AR) cDPrsT $@ $(real-prereqs)
258 # ---------------------------------------------------------------------------
260 quiet_cmd_objcopy = OBJCOPY $@
261 cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
264 # ---------------------------------------------------------------------------
266 quiet_cmd_gzip = GZIP $@
267 cmd_gzip = cat $(real-prereqs) | $(KGZIP) -n -f -9 > $@
270 # ---------------------------------------------------------------------------
271 DTC ?= $(objtree)/scripts/dtc/dtc
272 DTC_FLAGS += -Wno-interrupt_provider
274 # Disable noisy checks by default
275 ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
276 DTC_FLAGS += -Wno-unit_address_vs_reg \
277 -Wno-unit_address_format \
278 -Wno-avoid_unnecessary_addr_size \
280 -Wno-graph_child_address \
281 -Wno-simple_bus_reg \
282 -Wno-unique_unit_address \
286 ifneq ($(findstring 2,$(KBUILD_EXTRA_WARN)),)
287 DTC_FLAGS += -Wnode_name_chars_strict \
288 -Wproperty_name_chars_strict \
292 DTC_FLAGS += $(DTC_FLAGS_$(basetarget))
294 # Generate an assembly file to wrap the output of the device tree compiler
295 quiet_cmd_dt_S_dtb= DTB $@
298 echo '\#include <asm-generic/vmlinux.lds.h>'; \
299 echo '.section .dtb.init.rodata,"a"'; \
300 echo '.balign STRUCT_ALIGNMENT'; \
301 echo '.global __dtb_$(subst -,_,$(*F))_begin'; \
302 echo '__dtb_$(subst -,_,$(*F))_begin:'; \
303 echo '.incbin "$<" '; \
304 echo '__dtb_$(subst -,_,$(*F))_end:'; \
305 echo '.global __dtb_$(subst -,_,$(*F))_end'; \
306 echo '.balign STRUCT_ALIGNMENT'; \
309 $(obj)/%.dtb.S: $(obj)/%.dtb FORCE
310 $(call if_changed,dt_S_dtb)
312 quiet_cmd_dtc = DTC $@
313 cmd_dtc = $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
314 $(DTC) -O $(patsubst .%,%,$(suffix $@)) -o $@ -b 0 \
315 $(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
316 -d $(depfile).dtc.tmp $(dtc-tmp) ; \
317 cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
319 $(obj)/%.dtb: $(src)/%.dts $(DTC) FORCE
320 $(call if_changed_dep,dtc)
322 DT_CHECKER ?= dt-validate
323 DT_BINDING_DIR := Documentation/devicetree/bindings
324 # DT_TMP_SCHEMA may be overridden from Documentation/devicetree/bindings/Makefile
325 DT_TMP_SCHEMA ?= $(objtree)/$(DT_BINDING_DIR)/processed-schema.json
327 quiet_cmd_dtb_check = CHECK $@
328 cmd_dtb_check = $(DT_CHECKER) -u $(srctree)/$(DT_BINDING_DIR) -p $(DT_TMP_SCHEMA) $@
331 $(call cmd_and_fixdep,dtc)
332 $(call cmd,dtb_check)
335 $(obj)/%.dt.yaml: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE
336 $(call if_changed_rule,dtc,yaml)
338 dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
341 # ---------------------------------------------------------------------------
343 # Bzip2 and LZMA do not include size in file... so we have to fake that;
344 # append the size as a 32-bit littleendian number as gzip does.
345 size_append = printf $(shell \
347 for F in $(real-prereqs); do \
348 fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F); \
349 dec_size=$$(expr $$dec_size + $$fsize); \
351 printf "%08x\n" $$dec_size | \
352 sed 's/\(..\)/\1 /g' | { \
353 read ch0 ch1 ch2 ch3; \
354 for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \
355 printf '%s%03o' '\\' $$((0x$$ch)); \
360 quiet_cmd_bzip2 = BZIP2 $@
361 cmd_bzip2 = { cat $(real-prereqs) | $(KBZIP2) -9; $(size_append); } > $@
364 # ---------------------------------------------------------------------------
366 quiet_cmd_lzma = LZMA $@
367 cmd_lzma = { cat $(real-prereqs) | $(LZMA) -9; $(size_append); } > $@
369 quiet_cmd_lzo = LZO $@
370 cmd_lzo = { cat $(real-prereqs) | $(KLZOP) -9; $(size_append); } > $@
372 quiet_cmd_lz4 = LZ4 $@
373 cmd_lz4 = { cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout; \
374 $(size_append); } > $@
377 # ---------------------------------------------------------------------------
379 MKIMAGE := $(srctree)/scripts/mkuboot.sh
381 # SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
382 # the number of overrides in arch makefiles
383 UIMAGE_ARCH ?= $(SRCARCH)
384 UIMAGE_COMPRESSION ?= $(if $(2),$(2),none)
386 UIMAGE_TYPE ?= kernel
387 UIMAGE_LOADADDR ?= arch_must_set_this
388 UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)
389 UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)'
391 quiet_cmd_uimage = UIMAGE $@
392 cmd_uimage = $(BASH) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \
393 -C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \
395 -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \
396 -n $(UIMAGE_NAME) -d $< $@
399 # ---------------------------------------------------------------------------
400 # Use xzkern to compress the kernel image and xzmisc to compress other things.
402 # xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage
403 # of the kernel decompressor. A BCJ filter is used if it is available for
404 # the target architecture. xzkern also appends uncompressed size of the data
405 # using size_append. The .xz format has the size information available at
406 # the end of the file too, but it's in more complex format and it's good to
407 # avoid changing the part of the boot code that reads the uncompressed size.
408 # Note that the bytes added by size_append will make the xz tool think that
409 # the file is corrupt. This is expected.
411 # xzmisc doesn't use size_append, so it can be used to create normal .xz
412 # files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very
413 # big dictionary would increase the memory usage too much in the multi-call
414 # decompression mode. A BCJ filter isn't used either.
415 quiet_cmd_xzkern = XZKERN $@
416 cmd_xzkern = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \
417 $(size_append); } > $@
419 quiet_cmd_xzmisc = XZMISC $@
420 cmd_xzmisc = cat $(real-prereqs) | $(XZ) --check=crc32 --lzma2=dict=1MiB > $@
423 # ---------------------------------------------------------------------------
424 # Appends the uncompressed size of the data using size_append. The .zst
425 # format has the size information available at the beginning of the file too,
426 # but it's in a more complex format and it's good to avoid changing the part
427 # of the boot code that reads the uncompressed size.
429 # Note that the bytes added by size_append will make the zstd tool think that
430 # the file is corrupt. This is expected.
432 # zstd uses a maximum window size of 8 MB. zstd22 uses a maximum window size of
433 # 128 MB. zstd22 is used for kernel compression because it is decompressed in a
434 # single pass, so zstd doesn't need to allocate a window buffer. When streaming
435 # decompression is used, like initramfs decompression, zstd22 should likely not
436 # be used because it would require zstd to allocate a 128 MB buffer.
438 quiet_cmd_zstd = ZSTD $@
439 cmd_zstd = { cat $(real-prereqs) | $(ZSTD) -19; $(size_append); } > $@
441 quiet_cmd_zstd22 = ZSTD22 $@
442 cmd_zstd22 = { cat $(real-prereqs) | $(ZSTD) -22 --ultra; $(size_append); } > $@
445 # ---------------------------------------------------------------------------
447 # Default sed regexp - multiline due to syntax constraints
449 # Use [:space:] because LLVM's integrated assembler inserts <tab> around
450 # the .ascii directive whereas GCC keeps the <space> as-is.
452 's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \
453 /^->/{s:->#\(.*\):/* \1 */:; \
454 s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
458 # Use filechk to avoid rebuilds when a header changes, but the resulting file
460 define filechk_offsets
464 echo " * DO NOT MODIFY."; \
466 echo " * This file was generated by Kbuild"; \
469 sed -ne $(sed-offsets) < $<; \