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.o
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.o, $(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), or $(foo-m) 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))))
46 multi-used-m := $(sort $(foreach m,$(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))), $(m))))
47 multi-used := $(multi-used-y) $(multi-used-m)
48 single-used-m := $(sort $(filter-out $(multi-used-m),$(obj-m)))
50 # Build list of the parts of our composite objects, our composite
51 # objects depend on those (obviously)
52 multi-objs-y := $(foreach m, $(multi-used-y), $($(m:.o=-objs)) $($(m:.o=-y)))
53 multi-objs-m := $(foreach m, $(multi-used-m), $($(m:.o=-objs)) $($(m:.o=-y)))
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.o, $(obj-y))
59 # Replace multi-part objects by their individual parts, look at local dir only
60 real-objs-y := $(foreach m, $(filter-out $(subdir-obj-y), $(obj-y)), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m)))
61 real-objs-m := $(foreach m, $(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))),$($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)),$(m)))
64 # If CONFIG_OF_ALL_DTBS is enabled, all DT blobs are built
66 extra-$(CONFIG_OF_ALL_DTBS) += $(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-y := $(addprefix $(obj)/,$(obj-y))
75 obj-m := $(addprefix $(obj)/,$(obj-m))
76 lib-y := $(addprefix $(obj)/,$(lib-y))
77 subdir-obj-y := $(addprefix $(obj)/,$(subdir-obj-y))
78 real-objs-y := $(addprefix $(obj)/,$(real-objs-y))
79 real-objs-m := $(addprefix $(obj)/,$(real-objs-m))
80 single-used-m := $(addprefix $(obj)/,$(single-used-m))
81 multi-used-y := $(addprefix $(obj)/,$(multi-used-y))
82 multi-used-m := $(addprefix $(obj)/,$(multi-used-m))
83 multi-objs-y := $(addprefix $(obj)/,$(multi-objs-y))
84 multi-objs-m := $(addprefix $(obj)/,$(multi-objs-m))
85 subdir-ym := $(addprefix $(obj)/,$(subdir-ym))
87 # These flags are needed for modversions and compiling, so we define them here
88 # $(modname_flags) defines KBUILD_MODNAME as the name of the module it will
89 # end up in (or would, if it gets compiled in)
90 # Note: Files that end up in two or more modules are compiled without the
91 # KBUILD_MODNAME definition. The reason is that any made-up name would
92 # differ in different configs.
93 name-fix = $(squote)$(quote)$(subst $(comma),_,$(subst -,_,$1))$(quote)$(squote)
94 basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
95 modname_flags = $(if $(filter 1,$(words $(modname))),\
96 -DKBUILD_MODNAME=$(call name-fix,$(modname)))
98 orig_c_flags = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) \
99 $(ccflags-y) $(CFLAGS_$(basetarget).o)
100 _c_flags = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(orig_c_flags))
101 orig_a_flags = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) \
102 $(asflags-y) $(AFLAGS_$(basetarget).o)
103 _a_flags = $(filter-out $(AFLAGS_REMOVE_$(basetarget).o), $(orig_a_flags))
104 _cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(@F))
107 # Enable gcov profiling flags for a file, directory or for all files depending
108 # on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL
111 ifeq ($(CONFIG_GCOV_KERNEL),y)
112 _c_flags += $(if $(patsubst n%,, \
113 $(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \
118 # Enable address sanitizer flags for kernel except some files or directories
119 # we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE)
121 ifeq ($(CONFIG_KASAN),y)
122 _c_flags += $(if $(patsubst n%,, \
123 $(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \
124 $(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
127 ifeq ($(CONFIG_UBSAN),y)
128 _c_flags += $(if $(patsubst n%,, \
129 $(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
133 ifeq ($(CONFIG_KCOV),y)
134 _c_flags += $(if $(patsubst n%,, \
135 $(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \
139 # If building the kernel in a separate objtree expand all occurrences
140 # of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/').
142 ifeq ($(KBUILD_SRC),)
143 __c_flags = $(_c_flags)
144 __a_flags = $(_a_flags)
145 __cpp_flags = $(_cpp_flags)
148 # -I$(obj) locates generated .h files
149 # $(call addtree,-I$(obj)) locates .h files in srctree, from generated .c files
150 # and locates generated .h files
151 # FIXME: Replace both with specific CFLAGS* statements in the makefiles
152 __c_flags = $(if $(obj),$(call addtree,-I$(src)) -I$(obj)) \
153 $(call flags,_c_flags)
154 __a_flags = $(call flags,_a_flags)
155 __cpp_flags = $(call flags,_cpp_flags)
158 c_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
159 $(__c_flags) $(modkern_cflags) \
160 $(basename_flags) $(modname_flags)
162 a_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
163 $(__a_flags) $(modkern_aflags)
165 cpp_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
168 ld_flags = $(LDFLAGS) $(ldflags-y)
170 DTC_INCLUDE := $(srctree)/scripts/dtc/include-prefixes
172 dtc_cpp_flags = -Wp,-MD,$(depfile).pre.tmp -nostdinc \
173 $(addprefix -I,$(DTC_INCLUDE)) \
176 # Finds the multi-part object the current object will be linked into
177 modname-multi = $(sort $(foreach m,$(multi-used),\
178 $(if $(filter $(subst $(obj)/,,$*.o), $($(m:.o=-objs)) $($(m:.o=-y))),$(m:.o=))))
180 # Useful for describing the dependency of composite objects
182 # $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
184 $(foreach m, $(notdir $1), \
186 $(addprefix $(obj)/, $(foreach s, $3, $($(m:%$(strip $2)=%$(s)))))))
190 # ---------------------------------------------------------------------------
191 quiet_cmd_flex = LEX $@
192 cmd_flex = $(LEX) -o$@ -L $<
194 ifdef REGENERATE_PARSERS
195 .PRECIOUS: $(src)/%.lex.c_shipped
196 $(src)/%.lex.c_shipped: $(src)/%.l
200 .PRECIOUS: $(obj)/%.lex.c
201 $(filter %.lex.c,$(targets)): $(obj)/%.lex.c: $(src)/%.l FORCE
202 $(call if_changed,flex)
205 # ---------------------------------------------------------------------------
206 quiet_cmd_bison = YACC $@
207 cmd_bison = $(YACC) -o$@ -t -l $<
209 ifdef REGENERATE_PARSERS
210 .PRECIOUS: $(src)/%.tab.c_shipped
211 $(src)/%.tab.c_shipped: $(src)/%.y
215 .PRECIOUS: $(obj)/%.tab.c
216 $(filter %.tab.c,$(targets)): $(obj)/%.tab.c: $(src)/%.y FORCE
217 $(call if_changed,bison)
219 quiet_cmd_bison_h = YACC $@
220 cmd_bison_h = bison -o/dev/null --defines=$@ -t -l -p $(YACC_PREFIX) $<
222 ifdef REGENERATE_PARSERS
223 .PRECIOUS: $(src)/%.tab.h_shipped
224 $(src)/%.tab.h_shipped: $(src)/%.y
228 .PRECIOUS: $(obj)/%.tab.h
229 $(filter %.tab.h,$(targets)): $(obj)/%.tab.h: $(src)/%.y FORCE
230 $(call if_changed,bison_h)
233 # ===========================================================================
235 quiet_cmd_shipped = SHIPPED $@
236 cmd_shipped = cat $< > $@
238 $(obj)/%: $(src)/%_shipped
241 # Commands useful for building a boot image
242 # ===========================================================================
246 # target: source(s) FORCE
247 # $(if_changed,ld/objcopy/gzip)
249 # and add target to extra-y so that we know we have to
250 # read in the saved command line
253 # ---------------------------------------------------------------------------
256 cmd_ld = $(LD) $(LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F)) \
257 $(filter-out FORCE,$^) -o $@
260 # ---------------------------------------------------------------------------
262 quiet_cmd_objcopy = OBJCOPY $@
263 cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
266 # ---------------------------------------------------------------------------
268 quiet_cmd_gzip = GZIP $@
269 cmd_gzip = (cat $(filter-out FORCE,$^) | gzip -n -f -9 > $@) || \
273 # ---------------------------------------------------------------------------
274 DTC ?= $(objtree)/scripts/dtc/dtc
276 # Disable noisy checks by default
277 ifeq ($(findstring 1,$(KBUILD_ENABLE_EXTRA_GCC_CHECKS)),)
278 DTC_FLAGS += -Wno-unit_address_vs_reg \
279 -Wno-simple_bus_reg \
280 -Wno-unit_address_format \
282 -Wno-pci_device_bus_num \
286 ifneq ($(findstring 2,$(KBUILD_ENABLE_EXTRA_GCC_CHECKS)),)
287 DTC_FLAGS += -Wnode_name_chars_strict \
288 -Wproperty_name_chars_strict
291 DTC_FLAGS += $(DTC_FLAGS_$(basetarget))
293 # Generate an assembly file to wrap the output of the device tree compiler
294 quiet_cmd_dt_S_dtb= DTB $@
297 echo '\#include <asm-generic/vmlinux.lds.h>'; \
298 echo '.section .dtb.init.rodata,"a"'; \
299 echo '.balign STRUCT_ALIGNMENT'; \
300 echo '.global __dtb_$(*F)_begin'; \
301 echo '__dtb_$(*F)_begin:'; \
302 echo '.incbin "$<" '; \
303 echo '__dtb_$(*F)_end:'; \
304 echo '.global __dtb_$(*F)_end'; \
305 echo '.balign STRUCT_ALIGNMENT'; \
308 $(obj)/%.dtb.S: $(obj)/%.dtb
311 quiet_cmd_dtc = DTC $@
312 cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
313 $(CPP) $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
314 $(DTC) -O dtb -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 FORCE
320 $(call if_changed_dep,dtc)
322 dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
325 # ---------------------------------------------------------------------------
327 # Bzip2 and LZMA do not include size in file... so we have to fake that;
328 # append the size as a 32-bit littleendian number as gzip does.
329 size_append = printf $(shell \
332 fsize=$$(stat -c "%s" $$F); \
333 dec_size=$$(expr $$dec_size + $$fsize); \
335 printf "%08x\n" $$dec_size | \
336 sed 's/\(..\)/\1 /g' | { \
337 read ch0 ch1 ch2 ch3; \
338 for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \
339 printf '%s%03o' '\\' $$((0x$$ch)); \
344 quiet_cmd_bzip2 = BZIP2 $@
345 cmd_bzip2 = (cat $(filter-out FORCE,$^) | \
346 bzip2 -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
350 # ---------------------------------------------------------------------------
352 quiet_cmd_lzma = LZMA $@
353 cmd_lzma = (cat $(filter-out FORCE,$^) | \
354 lzma -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
357 quiet_cmd_lzo = LZO $@
358 cmd_lzo = (cat $(filter-out FORCE,$^) | \
359 lzop -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
362 quiet_cmd_lz4 = LZ4 $@
363 cmd_lz4 = (cat $(filter-out FORCE,$^) | \
364 lz4c -l -c1 stdin stdout && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
368 # ---------------------------------------------------------------------------
370 MKIMAGE := $(srctree)/scripts/mkuboot.sh
372 # SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
373 # the number of overrides in arch makefiles
374 UIMAGE_ARCH ?= $(SRCARCH)
375 UIMAGE_COMPRESSION ?= $(if $(2),$(2),none)
377 UIMAGE_TYPE ?= kernel
378 UIMAGE_LOADADDR ?= arch_must_set_this
379 UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)
380 UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)'
384 quiet_cmd_uimage = UIMAGE $(UIMAGE_OUT)
385 cmd_uimage = $(CONFIG_SHELL) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \
386 -C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \
388 -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \
389 -n $(UIMAGE_NAME) -d $(UIMAGE_IN) $(UIMAGE_OUT)
392 # ---------------------------------------------------------------------------
393 # Use xzkern to compress the kernel image and xzmisc to compress other things.
395 # xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage
396 # of the kernel decompressor. A BCJ filter is used if it is available for
397 # the target architecture. xzkern also appends uncompressed size of the data
398 # using size_append. The .xz format has the size information available at
399 # the end of the file too, but it's in more complex format and it's good to
400 # avoid changing the part of the boot code that reads the uncompressed size.
401 # Note that the bytes added by size_append will make the xz tool think that
402 # the file is corrupt. This is expected.
404 # xzmisc doesn't use size_append, so it can be used to create normal .xz
405 # files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very
406 # big dictionary would increase the memory usage too much in the multi-call
407 # decompression mode. A BCJ filter isn't used either.
408 quiet_cmd_xzkern = XZKERN $@
409 cmd_xzkern = (cat $(filter-out FORCE,$^) | \
410 sh $(srctree)/scripts/xz_wrap.sh && \
411 $(call size_append, $(filter-out FORCE,$^))) > $@ || \
414 quiet_cmd_xzmisc = XZMISC $@
415 cmd_xzmisc = (cat $(filter-out FORCE,$^) | \
416 xz --check=crc32 --lzma2=dict=1MiB) > $@ || \
420 # ---------------------------------------------------------------------------
422 # Default sed regexp - multiline due to syntax constraints
424 # Use [:space:] because LLVM's integrated assembler inserts <tab> around
425 # the .ascii directive whereas GCC keeps the <space> as-is.
427 's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \
428 /^->/{s:->#\(.*\):/* \1 */:; \
429 s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
433 # Use filechk to avoid rebuilds when a header changes, but the resulting file
435 define filechk_offsets
440 echo " * DO NOT MODIFY."; \
442 echo " * This file was generated by Kbuild"; \
445 sed -ne $(sed-offsets); \