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 hostprogs += $(hostprogs-y) $(hostprogs-m)
10 # flags that take effect in current and sub directories
11 KBUILD_AFLAGS += $(subdir-asflags-y)
12 KBUILD_CFLAGS += $(subdir-ccflags-y)
14 # Figure out what we need to build from the various variables
15 # ===========================================================================
17 # When an object is listed to be built compiled-in and modular,
18 # only build the compiled-in version
19 obj-m := $(filter-out $(obj-y),$(obj-m))
21 # Libraries are always collected in one lib file.
22 # Filter out objects already built-in
23 lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m)))
26 # Unfortunately, we don't have information about ordering between -y
27 # and -m subdirs. Just put -y's first.
28 modorder := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m:.o=.ko))
30 # Handle objects in subdirs
31 # ---------------------------------------------------------------------------
32 # o if we encounter foo/ in $(obj-y), replace it by foo/built-in.a
33 # and add the directory to the list of dirs to descend into: $(subdir-y)
34 # o if we encounter foo/ in $(obj-m), remove it from $(obj-m)
35 # and add the directory to the list of dirs to descend into: $(subdir-m)
36 __subdir-y := $(patsubst %/,%,$(filter %/, $(obj-y)))
37 subdir-y += $(__subdir-y)
38 __subdir-m := $(patsubst %/,%,$(filter %/, $(obj-m)))
39 subdir-m += $(__subdir-m)
41 obj-y := $(patsubst %/, %/built-in.a, $(obj-y))
43 obj-y := $(filter-out %/, $(obj-y))
45 obj-m := $(filter-out %/, $(obj-m))
47 # Subdirectories we need to descend into
48 subdir-ym := $(sort $(subdir-y) $(subdir-m))
50 # If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object
51 multi-used-y := $(sort $(foreach m,$(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-))), $(m))))
52 multi-used-m := $(sort $(foreach m,$(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)) $($(m:.o=-))), $(m))))
53 multi-used := $(multi-used-y) $(multi-used-m)
55 # $(subdir-obj-y) is the list of objects in $(obj-y) which uses dir/ to
56 # tell kbuild to descend
57 subdir-obj-y := $(filter %/built-in.a, $(obj-y))
59 # Replace multi-part objects by their individual parts,
60 # including built-in.a from subdirectories
61 real-obj-y := $(foreach m, $(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m)))
62 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)))
64 always-y += $(always-m)
67 # If CONFIG_OF_ALL_DTBS is enabled, all DT blobs are built
69 extra-$(CONFIG_OF_ALL_DTBS) += $(dtb-)
71 ifneq ($(CHECK_DTBS),)
72 extra-y += $(patsubst %.dtb,%.dt.yaml, $(dtb-y))
73 extra-$(CONFIG_OF_ALL_DTBS) += $(patsubst %.dtb,%.dt.yaml, $(dtb-))
78 extra-y := $(addprefix $(obj)/,$(extra-y))
79 always-y := $(addprefix $(obj)/,$(always-y))
80 targets := $(addprefix $(obj)/,$(targets))
81 modorder := $(addprefix $(obj)/,$(modorder))
82 obj-m := $(addprefix $(obj)/,$(obj-m))
83 lib-y := $(addprefix $(obj)/,$(lib-y))
84 subdir-obj-y := $(addprefix $(obj)/,$(subdir-obj-y))
85 real-obj-y := $(addprefix $(obj)/,$(real-obj-y))
86 real-obj-m := $(addprefix $(obj)/,$(real-obj-m))
87 multi-used-m := $(addprefix $(obj)/,$(multi-used-m))
88 subdir-ym := $(addprefix $(obj)/,$(subdir-ym))
90 # Finds the multi-part object the current object will be linked into.
91 # If the object belongs to two or more multi-part objects, list them all.
92 modname-multi = $(sort $(foreach m,$(multi-used),\
93 $(if $(filter $*.o, $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))),$(m:.o=))))
95 __modname = $(if $(modname-multi),$(modname-multi),$(basetarget))
97 modname = $(subst $(space),:,$(__modname))
98 modfile = $(addprefix $(obj)/,$(__modname))
100 # target with $(obj)/ and its suffix stripped
101 target-stem = $(basename $(patsubst $(obj)/%,%,$@))
103 # These flags are needed for modversions and compiling, so we define them here
104 # $(modname_flags) defines KBUILD_MODNAME as the name of the module it will
105 # end up in (or would, if it gets compiled in)
106 name-fix = $(call stringify,$(subst $(comma),_,$(subst -,_,$1)))
107 basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
108 modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname))
109 modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile))
111 orig_c_flags = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) \
112 $(ccflags-y) $(CFLAGS_$(target-stem).o)
113 _c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), $(orig_c_flags))
114 orig_a_flags = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) \
115 $(asflags-y) $(AFLAGS_$(target-stem).o)
116 _a_flags = $(filter-out $(AFLAGS_REMOVE_$(target-stem).o), $(orig_a_flags))
117 _cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(target-stem).lds)
120 # Enable gcov profiling flags for a file, directory or for all files depending
121 # on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL
124 ifeq ($(CONFIG_GCOV_KERNEL),y)
125 _c_flags += $(if $(patsubst n%,, \
126 $(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \
131 # Enable address sanitizer flags for kernel except some files or directories
132 # we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE)
134 ifeq ($(CONFIG_KASAN),y)
135 _c_flags += $(if $(patsubst n%,, \
136 $(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \
137 $(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
140 ifeq ($(CONFIG_UBSAN),y)
141 _c_flags += $(if $(patsubst n%,, \
142 $(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
146 ifeq ($(CONFIG_KCOV),y)
147 _c_flags += $(if $(patsubst n%,, \
148 $(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \
152 # $(srctree)/$(src) for including checkin headers from generated source files
153 # $(objtree)/$(obj) for including generated headers from checkin source files
154 ifeq ($(KBUILD_EXTMOD),)
155 ifdef building_out_of_srctree
156 _c_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
157 _a_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
158 _cpp_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
162 part-of-module = $(if $(filter $(basename $@).o, $(real-obj-m)),y)
163 quiet_modtag = $(if $(part-of-module),[M], )
166 $(if $(part-of-module), \
167 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
168 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL) $(modfile_flags))
170 modkern_aflags = $(if $(part-of-module), \
171 $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE), \
172 $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL))
174 c_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
175 -include $(srctree)/include/linux/compiler_types.h \
176 $(_c_flags) $(modkern_cflags) \
177 $(basename_flags) $(modname_flags)
179 a_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
180 $(_a_flags) $(modkern_aflags)
182 cpp_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
185 ld_flags = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F))
187 DTC_INCLUDE := $(srctree)/scripts/dtc/include-prefixes
189 dtc_cpp_flags = -Wp,-MD,$(depfile).pre.tmp -nostdinc \
190 $(addprefix -I,$(DTC_INCLUDE)) \
193 # Useful for describing the dependency of composite objects
195 # $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
197 $(foreach m, $(notdir $1), \
199 $(addprefix $(obj)/, $(foreach s, $3, $($(m:%$(strip $2)=%$(s)))))))
203 # ===========================================================================
205 quiet_cmd_shipped = SHIPPED $@
206 cmd_shipped = cat $< > $@
208 $(obj)/%: $(src)/%_shipped
211 # Commands useful for building a boot image
212 # ===========================================================================
216 # target: source(s) FORCE
217 # $(if_changed,ld/objcopy/gzip)
219 # and add target to extra-y so that we know we have to
220 # read in the saved command line
223 # ---------------------------------------------------------------------------
226 cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@
229 # ---------------------------------------------------------------------------
232 cmd_ar = rm -f $@; $(AR) cDPrsT $@ $(real-prereqs)
235 # ---------------------------------------------------------------------------
237 quiet_cmd_objcopy = OBJCOPY $@
238 cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
241 # ---------------------------------------------------------------------------
243 quiet_cmd_gzip = GZIP $@
244 cmd_gzip = cat $(real-prereqs) | gzip -n -f -9 > $@
247 # ---------------------------------------------------------------------------
248 DTC ?= $(objtree)/scripts/dtc/dtc
250 # Disable noisy checks by default
251 ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
252 DTC_FLAGS += -Wno-unit_address_vs_reg \
253 -Wno-unit_address_format \
254 -Wno-avoid_unnecessary_addr_size \
256 -Wno-graph_child_address \
257 -Wno-simple_bus_reg \
258 -Wno-unique_unit_address \
262 ifneq ($(findstring 2,$(KBUILD_EXTRA_WARN)),)
263 DTC_FLAGS += -Wnode_name_chars_strict \
264 -Wproperty_name_chars_strict
267 DTC_FLAGS += $(DTC_FLAGS_$(basetarget))
269 # Generate an assembly file to wrap the output of the device tree compiler
270 quiet_cmd_dt_S_dtb= DTB $@
273 echo '\#include <asm-generic/vmlinux.lds.h>'; \
274 echo '.section .dtb.init.rodata,"a"'; \
275 echo '.balign STRUCT_ALIGNMENT'; \
276 echo '.global __dtb_$(subst -,_,$(*F))_begin'; \
277 echo '__dtb_$(subst -,_,$(*F))_begin:'; \
278 echo '.incbin "$<" '; \
279 echo '__dtb_$(subst -,_,$(*F))_end:'; \
280 echo '.global __dtb_$(subst -,_,$(*F))_end'; \
281 echo '.balign STRUCT_ALIGNMENT'; \
284 $(obj)/%.dtb.S: $(obj)/%.dtb FORCE
285 $(call if_changed,dt_S_dtb)
287 quiet_cmd_dtc = DTC $@
288 cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
289 $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
290 $(DTC) -O $(2) -o $@ -b 0 \
291 $(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
292 -d $(depfile).dtc.tmp $(dtc-tmp) ; \
293 cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
295 $(obj)/%.dtb: $(src)/%.dts $(DTC) FORCE
296 $(call if_changed_dep,dtc,dtb)
298 DT_CHECKER ?= dt-validate
299 DT_BINDING_DIR := Documentation/devicetree/bindings
300 DT_TMP_SCHEMA := $(objtree)/$(DT_BINDING_DIR)/processed-schema.yaml
302 quiet_cmd_dtb_check = CHECK $@
303 cmd_dtb_check = $(DT_CHECKER) -u $(srctree)/$(DT_BINDING_DIR) -p $(DT_TMP_SCHEMA) $@ ;
305 define rule_dtc_dt_yaml
306 $(call cmd_and_fixdep,dtc,yaml)
307 $(call cmd,dtb_check)
310 $(obj)/%.dt.yaml: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE
311 $(call if_changed_rule,dtc_dt_yaml)
313 dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
316 # ---------------------------------------------------------------------------
318 # Bzip2 and LZMA do not include size in file... so we have to fake that;
319 # append the size as a 32-bit littleendian number as gzip does.
320 size_append = printf $(shell \
322 for F in $(real-prereqs); do \
323 fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F); \
324 dec_size=$$(expr $$dec_size + $$fsize); \
326 printf "%08x\n" $$dec_size | \
327 sed 's/\(..\)/\1 /g' | { \
328 read ch0 ch1 ch2 ch3; \
329 for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \
330 printf '%s%03o' '\\' $$((0x$$ch)); \
335 quiet_cmd_bzip2 = BZIP2 $@
336 cmd_bzip2 = { cat $(real-prereqs) | bzip2 -9; $(size_append); } > $@
339 # ---------------------------------------------------------------------------
341 quiet_cmd_lzma = LZMA $@
342 cmd_lzma = { cat $(real-prereqs) | lzma -9; $(size_append); } > $@
344 quiet_cmd_lzo = LZO $@
345 cmd_lzo = { cat $(real-prereqs) | lzop -9; $(size_append); } > $@
347 quiet_cmd_lz4 = LZ4 $@
348 cmd_lz4 = { cat $(real-prereqs) | lz4c -l -c1 stdin stdout; \
349 $(size_append); } > $@
352 # ---------------------------------------------------------------------------
354 MKIMAGE := $(srctree)/scripts/mkuboot.sh
356 # SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
357 # the number of overrides in arch makefiles
358 UIMAGE_ARCH ?= $(SRCARCH)
359 UIMAGE_COMPRESSION ?= $(if $(2),$(2),none)
361 UIMAGE_TYPE ?= kernel
362 UIMAGE_LOADADDR ?= arch_must_set_this
363 UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)
364 UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)'
366 quiet_cmd_uimage = UIMAGE $@
367 cmd_uimage = $(BASH) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \
368 -C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \
370 -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \
371 -n $(UIMAGE_NAME) -d $< $@
374 # ---------------------------------------------------------------------------
375 # Use xzkern to compress the kernel image and xzmisc to compress other things.
377 # xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage
378 # of the kernel decompressor. A BCJ filter is used if it is available for
379 # the target architecture. xzkern also appends uncompressed size of the data
380 # using size_append. The .xz format has the size information available at
381 # the end of the file too, but it's in more complex format and it's good to
382 # avoid changing the part of the boot code that reads the uncompressed size.
383 # Note that the bytes added by size_append will make the xz tool think that
384 # the file is corrupt. This is expected.
386 # xzmisc doesn't use size_append, so it can be used to create normal .xz
387 # files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very
388 # big dictionary would increase the memory usage too much in the multi-call
389 # decompression mode. A BCJ filter isn't used either.
390 quiet_cmd_xzkern = XZKERN $@
391 cmd_xzkern = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \
392 $(size_append); } > $@
394 quiet_cmd_xzmisc = XZMISC $@
395 cmd_xzmisc = cat $(real-prereqs) | xz --check=crc32 --lzma2=dict=1MiB > $@
398 # ---------------------------------------------------------------------------
400 # Default sed regexp - multiline due to syntax constraints
402 # Use [:space:] because LLVM's integrated assembler inserts <tab> around
403 # the .ascii directive whereas GCC keeps the <space> as-is.
405 's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \
406 /^->/{s:->#\(.*\):/* \1 */:; \
407 s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
411 # Use filechk to avoid rebuilds when a header changes, but the resulting file
413 define filechk_offsets
417 echo " * DO NOT MODIFY."; \
419 echo " * This file was generated by Kbuild"; \
422 sed -ne $(sed-offsets) < $<; \