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)))
24 # Unfortunately, we don't have information about ordering between -y
25 # and -m subdirs. Just put -y's first.
26 modorder := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m:.o=.ko))
28 # Handle objects in subdirs
29 # ---------------------------------------------------------------------------
30 # o if we encounter foo/ in $(obj-y), replace it by foo/built-in.a
31 # and add the directory to the list of dirs to descend into: $(subdir-y)
32 # o if we encounter foo/ in $(obj-m), remove it from $(obj-m)
33 # and add the directory to the list of dirs to descend into: $(subdir-m)
34 __subdir-y := $(patsubst %/,%,$(filter %/, $(obj-y)))
35 subdir-y += $(__subdir-y)
36 __subdir-m := $(patsubst %/,%,$(filter %/, $(obj-m)))
37 subdir-m += $(__subdir-m)
38 obj-y := $(patsubst %/, %/built-in.a, $(obj-y))
39 obj-m := $(filter-out %/, $(obj-m))
41 # Subdirectories we need to descend into
42 subdir-ym := $(sort $(subdir-y) $(subdir-m))
44 # If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object
45 multi-used-y := $(sort $(foreach m,$(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-))), $(m))))
46 multi-used-m := $(sort $(foreach m,$(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)) $($(m:.o=-))), $(m))))
47 multi-used := $(multi-used-y) $(multi-used-m)
49 # $(subdir-obj-y) is the list of objects in $(obj-y) which uses dir/ to
50 # tell kbuild to descend
51 subdir-obj-y := $(filter %/built-in.a, $(obj-y))
53 # Replace multi-part objects by their individual parts,
54 # including built-in.a from subdirectories
55 real-obj-y := $(foreach m, $(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m)))
56 real-obj-m := $(foreach m, $(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)) $($(m:.o=-))),$($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)),$(m)))
59 # If CONFIG_OF_ALL_DTBS is enabled, all DT blobs are built
61 extra-$(CONFIG_OF_ALL_DTBS) += $(dtb-)
63 ifneq ($(CHECK_DTBS),)
64 extra-y += $(patsubst %.dtb,%.dt.yaml, $(dtb-y))
65 extra-$(CONFIG_OF_ALL_DTBS) += $(patsubst %.dtb,%.dt.yaml, $(dtb-))
70 extra-y := $(addprefix $(obj)/,$(extra-y))
71 always := $(addprefix $(obj)/,$(always))
72 targets := $(addprefix $(obj)/,$(targets))
73 modorder := $(addprefix $(obj)/,$(modorder))
74 obj-m := $(addprefix $(obj)/,$(obj-m))
75 lib-y := $(addprefix $(obj)/,$(lib-y))
76 subdir-obj-y := $(addprefix $(obj)/,$(subdir-obj-y))
77 real-obj-y := $(addprefix $(obj)/,$(real-obj-y))
78 real-obj-m := $(addprefix $(obj)/,$(real-obj-m))
79 multi-used-m := $(addprefix $(obj)/,$(multi-used-m))
80 subdir-ym := $(addprefix $(obj)/,$(subdir-ym))
82 # Finds the multi-part object the current object will be linked into.
83 # If the object belongs to two or more multi-part objects, all of them are
84 # concatenated with a colon separator.
85 modname-multi = $(subst $(space),:,$(sort $(foreach m,$(multi-used),\
86 $(if $(filter $*.o, $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))),$(m:.o=)))))
88 modname = $(if $(modname-multi),$(modname-multi),$(basetarget))
90 # target with $(obj)/ and its suffix stripped
91 target-stem = $(basename $(patsubst $(obj)/%,%,$@))
93 # These flags are needed for modversions and compiling, so we define them here
94 # $(modname_flags) defines KBUILD_MODNAME as the name of the module it will
95 # end up in (or would, if it gets compiled in)
96 name-fix = $(squote)$(quote)$(subst $(comma),_,$(subst -,_,$1))$(quote)$(squote)
97 basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
98 modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname))
100 orig_c_flags = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) \
101 $(ccflags-y) $(CFLAGS_$(target-stem).o)
102 _c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), $(orig_c_flags))
103 orig_a_flags = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) \
104 $(asflags-y) $(AFLAGS_$(target-stem).o)
105 _a_flags = $(filter-out $(AFLAGS_REMOVE_$(target-stem).o), $(orig_a_flags))
106 _cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(target-stem).lds)
109 # Enable gcov profiling flags for a file, directory or for all files depending
110 # on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL
113 ifeq ($(CONFIG_GCOV_KERNEL),y)
114 _c_flags += $(if $(patsubst n%,, \
115 $(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \
120 # Enable address sanitizer flags for kernel except some files or directories
121 # we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE)
123 ifeq ($(CONFIG_KASAN),y)
124 _c_flags += $(if $(patsubst n%,, \
125 $(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \
126 $(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
129 ifeq ($(CONFIG_UBSAN),y)
130 _c_flags += $(if $(patsubst n%,, \
131 $(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
135 ifeq ($(CONFIG_KCOV),y)
136 _c_flags += $(if $(patsubst n%,, \
137 $(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \
141 # $(srctree)/$(src) for including checkin headers from generated source files
142 # $(objtree)/$(obj) for including generated headers from checkin source files
143 ifeq ($(KBUILD_EXTMOD),)
144 ifdef building_out_of_srctree
145 _c_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
146 _a_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
147 _cpp_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
151 part-of-module = $(if $(filter $(basename $@).o, $(real-obj-m)),y)
152 quiet_modtag = $(if $(part-of-module),[M], )
155 $(if $(part-of-module), \
156 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
157 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
159 modkern_aflags = $(if $(part-of-module), \
160 $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE), \
161 $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL))
163 c_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
164 -include $(srctree)/include/linux/compiler_types.h \
165 $(_c_flags) $(modkern_cflags) \
166 $(basename_flags) $(modname_flags)
168 a_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
169 $(_a_flags) $(modkern_aflags)
171 cpp_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
174 ld_flags = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F))
176 DTC_INCLUDE := $(srctree)/scripts/dtc/include-prefixes
178 dtc_cpp_flags = -Wp,-MD,$(depfile).pre.tmp -nostdinc \
179 $(addprefix -I,$(DTC_INCLUDE)) \
182 # Useful for describing the dependency of composite objects
184 # $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
186 $(foreach m, $(notdir $1), \
188 $(addprefix $(obj)/, $(foreach s, $3, $($(m:%$(strip $2)=%$(s)))))))
192 # ===========================================================================
194 quiet_cmd_shipped = SHIPPED $@
195 cmd_shipped = cat $< > $@
197 $(obj)/%: $(src)/%_shipped
200 # Commands useful for building a boot image
201 # ===========================================================================
205 # target: source(s) FORCE
206 # $(if_changed,ld/objcopy/gzip)
208 # and add target to extra-y so that we know we have to
209 # read in the saved command line
212 # ---------------------------------------------------------------------------
215 cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@
218 # ---------------------------------------------------------------------------
221 cmd_ar = rm -f $@; $(AR) cDPrsT $@ $(real-prereqs)
224 # ---------------------------------------------------------------------------
226 quiet_cmd_objcopy = OBJCOPY $@
227 cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
230 # ---------------------------------------------------------------------------
232 quiet_cmd_gzip = GZIP $@
233 cmd_gzip = cat $(real-prereqs) | gzip -n -f -9 > $@
236 # ---------------------------------------------------------------------------
237 DTC ?= $(objtree)/scripts/dtc/dtc
239 # Disable noisy checks by default
240 ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
241 DTC_FLAGS += -Wno-unit_address_vs_reg \
242 -Wno-unit_address_format \
243 -Wno-avoid_unnecessary_addr_size \
245 -Wno-graph_child_address \
246 -Wno-simple_bus_reg \
247 -Wno-unique_unit_address \
251 ifneq ($(findstring 2,$(KBUILD_EXTRA_WARN)),)
252 DTC_FLAGS += -Wnode_name_chars_strict \
253 -Wproperty_name_chars_strict
256 DTC_FLAGS += $(DTC_FLAGS_$(basetarget))
258 # Generate an assembly file to wrap the output of the device tree compiler
259 quiet_cmd_dt_S_dtb= DTB $@
262 echo '\#include <asm-generic/vmlinux.lds.h>'; \
263 echo '.section .dtb.init.rodata,"a"'; \
264 echo '.balign STRUCT_ALIGNMENT'; \
265 echo '.global __dtb_$(subst -,_,$(*F))_begin'; \
266 echo '__dtb_$(subst -,_,$(*F))_begin:'; \
267 echo '.incbin "$<" '; \
268 echo '__dtb_$(subst -,_,$(*F))_end:'; \
269 echo '.global __dtb_$(subst -,_,$(*F))_end'; \
270 echo '.balign STRUCT_ALIGNMENT'; \
273 $(obj)/%.dtb.S: $(obj)/%.dtb FORCE
274 $(call if_changed,dt_S_dtb)
276 quiet_cmd_dtc = DTC $@
277 cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
278 $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
279 $(DTC) -O $(2) -o $@ -b 0 \
280 $(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
281 -d $(depfile).dtc.tmp $(dtc-tmp) ; \
282 cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
284 $(obj)/%.dtb: $(src)/%.dts $(DTC) FORCE
285 $(call if_changed_dep,dtc,dtb)
287 DT_CHECKER ?= dt-validate
288 DT_BINDING_DIR := Documentation/devicetree/bindings
289 DT_TMP_SCHEMA := $(objtree)/$(DT_BINDING_DIR)/processed-schema.yaml
291 quiet_cmd_dtb_check = CHECK $@
292 cmd_dtb_check = $(DT_CHECKER) -u $(srctree)/$(DT_BINDING_DIR) -p $(DT_TMP_SCHEMA) $@ ;
295 $(call cmd_and_fixdep,dtc,yaml)
296 $(call cmd,dtb_check)
299 $(obj)/%.dt.yaml: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE
300 $(call if_changed_rule,dtc,yaml)
302 dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
305 # ---------------------------------------------------------------------------
307 # Bzip2 and LZMA do not include size in file... so we have to fake that;
308 # append the size as a 32-bit littleendian number as gzip does.
309 size_append = printf $(shell \
311 for F in $(real-prereqs); do \
312 fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F); \
313 dec_size=$$(expr $$dec_size + $$fsize); \
315 printf "%08x\n" $$dec_size | \
316 sed 's/\(..\)/\1 /g' | { \
317 read ch0 ch1 ch2 ch3; \
318 for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \
319 printf '%s%03o' '\\' $$((0x$$ch)); \
324 quiet_cmd_bzip2 = BZIP2 $@
325 cmd_bzip2 = { cat $(real-prereqs) | bzip2 -9; $(size_append); } > $@
328 # ---------------------------------------------------------------------------
330 quiet_cmd_lzma = LZMA $@
331 cmd_lzma = { cat $(real-prereqs) | lzma -9; $(size_append); } > $@
333 quiet_cmd_lzo = LZO $@
334 cmd_lzo = { cat $(real-prereqs) | lzop -9; $(size_append); } > $@
336 quiet_cmd_lz4 = LZ4 $@
337 cmd_lz4 = { cat $(real-prereqs) | lz4c -l -c1 stdin stdout; \
338 $(size_append); } > $@
341 # ---------------------------------------------------------------------------
343 MKIMAGE := $(srctree)/scripts/mkuboot.sh
345 # SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
346 # the number of overrides in arch makefiles
347 UIMAGE_ARCH ?= $(SRCARCH)
348 UIMAGE_COMPRESSION ?= $(if $(2),$(2),none)
350 UIMAGE_TYPE ?= kernel
351 UIMAGE_LOADADDR ?= arch_must_set_this
352 UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)
353 UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)'
355 quiet_cmd_uimage = UIMAGE $@
356 cmd_uimage = $(BASH) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \
357 -C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \
359 -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \
360 -n $(UIMAGE_NAME) -d $< $@
363 # ---------------------------------------------------------------------------
364 # Use xzkern to compress the kernel image and xzmisc to compress other things.
366 # xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage
367 # of the kernel decompressor. A BCJ filter is used if it is available for
368 # the target architecture. xzkern also appends uncompressed size of the data
369 # using size_append. The .xz format has the size information available at
370 # the end of the file too, but it's in more complex format and it's good to
371 # avoid changing the part of the boot code that reads the uncompressed size.
372 # Note that the bytes added by size_append will make the xz tool think that
373 # the file is corrupt. This is expected.
375 # xzmisc doesn't use size_append, so it can be used to create normal .xz
376 # files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very
377 # big dictionary would increase the memory usage too much in the multi-call
378 # decompression mode. A BCJ filter isn't used either.
379 quiet_cmd_xzkern = XZKERN $@
380 cmd_xzkern = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \
381 $(size_append); } > $@
383 quiet_cmd_xzmisc = XZMISC $@
384 cmd_xzmisc = cat $(real-prereqs) | xz --check=crc32 --lzma2=dict=1MiB > $@
387 # ---------------------------------------------------------------------------
389 # Default sed regexp - multiline due to syntax constraints
391 # Use [:space:] because LLVM's integrated assembler inserts <tab> around
392 # the .ascii directive whereas GCC keeps the <space> as-is.
394 's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \
395 /^->/{s:->#\(.*\):/* \1 */:; \
396 s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
400 # Use filechk to avoid rebuilds when a header changes, but the resulting file
402 define filechk_offsets
406 echo " * DO NOT MODIFY."; \
408 echo " * This file was generated by Kbuild"; \
411 sed -ne $(sed-offsets) < $<; \