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)
9 # flags that take effect in sub directories
10 export KBUILD_SUBDIR_ASFLAGS := $(KBUILD_SUBDIR_ASFLAGS) $(subdir-asflags-y)
11 export KBUILD_SUBDIR_CCFLAGS := $(KBUILD_SUBDIR_CCFLAGS) $(subdir-ccflags-y)
13 # Figure out what we need to build from the various variables
14 # ===========================================================================
16 # When an object is listed to be built compiled-in and modular,
17 # 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
24 lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m)))
27 # Handle objects in subdirs
28 # ---------------------------------------------------------------------------
29 # o if we encounter foo/ in $(obj-y), replace it by foo/built-in.o
30 # and add the directory to the list of dirs to descend into: $(subdir-y)
31 # o if we encounter foo/ in $(obj-m), remove it from $(obj-m)
32 # and add the directory to the list of dirs to descend into: $(subdir-m)
35 # Unfortunately, we don't have information about ordering between -y
36 # and -m subdirs. Just put -y's first.
37 modorder := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m:.o=.ko))
39 __subdir-y := $(patsubst %/,%,$(filter %/, $(obj-y)))
40 subdir-y += $(__subdir-y)
41 __subdir-m := $(patsubst %/,%,$(filter %/, $(obj-m)))
42 subdir-m += $(__subdir-m)
43 obj-y := $(patsubst %/, %/built-in.o, $(obj-y))
44 obj-m := $(filter-out %/, $(obj-m))
46 # Subdirectories we need to descend into
48 subdir-ym := $(sort $(subdir-y) $(subdir-m))
50 # if $(foo-objs) 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))))
52 multi-used-m := $(sort $(foreach m,$(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))), $(m))))
53 multi-used := $(multi-used-y) $(multi-used-m)
54 single-used-m := $(sort $(filter-out $(multi-used-m),$(obj-m)))
56 # Build list of the parts of our composite objects, our composite
57 # objects depend on those (obviously)
58 multi-objs-y := $(foreach m, $(multi-used-y), $($(m:.o=-objs)) $($(m:.o=-y)))
59 multi-objs-m := $(foreach m, $(multi-used-m), $($(m:.o=-objs)) $($(m:.o=-y)))
60 multi-objs := $(multi-objs-y) $(multi-objs-m)
62 # $(subdir-obj-y) is the list of objects in $(obj-y) which uses dir/ to
63 # tell kbuild to descend
64 subdir-obj-y := $(filter %/built-in.o, $(obj-y))
66 # $(obj-dirs) is a list of directories that contain object files
67 obj-dirs := $(dir $(multi-objs) $(obj-y))
69 # Replace multi-part objects by their individual parts, look at local dir only
70 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))) $(extra-y)
71 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)))
75 extra-y := $(addprefix $(obj)/,$(extra-y))
76 always := $(addprefix $(obj)/,$(always))
77 targets := $(addprefix $(obj)/,$(targets))
78 modorder := $(addprefix $(obj)/,$(modorder))
79 obj-y := $(addprefix $(obj)/,$(obj-y))
80 obj-m := $(addprefix $(obj)/,$(obj-m))
81 lib-y := $(addprefix $(obj)/,$(lib-y))
82 subdir-obj-y := $(addprefix $(obj)/,$(subdir-obj-y))
83 real-objs-y := $(addprefix $(obj)/,$(real-objs-y))
84 real-objs-m := $(addprefix $(obj)/,$(real-objs-m))
85 single-used-m := $(addprefix $(obj)/,$(single-used-m))
86 multi-used-y := $(addprefix $(obj)/,$(multi-used-y))
87 multi-used-m := $(addprefix $(obj)/,$(multi-used-m))
88 multi-objs-y := $(addprefix $(obj)/,$(multi-objs-y))
89 multi-objs-m := $(addprefix $(obj)/,$(multi-objs-m))
90 subdir-ym := $(addprefix $(obj)/,$(subdir-ym))
91 obj-dirs := $(addprefix $(obj)/,$(obj-dirs))
93 # These flags are needed for modversions and compiling, so we define them here
95 # $(modname_flags) #defines KBUILD_MODNAME as the name of the module it will
96 # end up in (or would, if it gets compiled in)
97 # Note: Files that end up in two or more modules are compiled without the
98 # KBUILD_MODNAME definition. The reason is that any made-up name would
99 # differ in different configs.
100 name-fix = $(squote)$(quote)$(subst $(comma),_,$(subst -,_,$1))$(quote)$(squote)
101 basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
102 modname_flags = $(if $(filter 1,$(words $(modname))),\
103 -DKBUILD_MODNAME=$(call name-fix,$(modname)))
105 orig_c_flags = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(KBUILD_SUBDIR_CCFLAGS) \
106 $(ccflags-y) $(CFLAGS_$(basetarget).o)
107 _c_flags = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(orig_c_flags))
108 orig_a_flags = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(KBUILD_SUBDIR_ASFLAGS) \
109 $(asflags-y) $(AFLAGS_$(basetarget).o)
110 _a_flags = $(filter-out $(AFLAGS_REMOVE_$(basetarget).o), $(orig_a_flags))
111 _cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(@F))
114 # Enable gcov profiling flags for a file, directory or for all files depending
115 # on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL
118 ifeq ($(CONFIG_GCOV_KERNEL),y)
119 _c_flags += $(if $(patsubst n%,, \
120 $(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \
125 # Enable address sanitizer flags for kernel except some files or directories
126 # we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE)
128 ifeq ($(CONFIG_KASAN),y)
129 _c_flags += $(if $(patsubst n%,, \
130 $(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \
131 $(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
134 ifeq ($(CONFIG_UBSAN),y)
135 _c_flags += $(if $(patsubst n%,, \
136 $(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
140 ifeq ($(CONFIG_KCOV),y)
141 _c_flags += $(if $(patsubst n%,, \
142 $(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \
146 # If building the kernel in a separate objtree expand all occurrences
147 # of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/').
149 ifeq ($(KBUILD_SRC),)
150 __c_flags = $(_c_flags)
151 __a_flags = $(_a_flags)
152 __cpp_flags = $(_cpp_flags)
155 # -I$(obj) locates generated .h files
156 # $(call addtree,-I$(obj)) locates .h files in srctree, from generated .c files
157 # and locates generated .h files
158 # FIXME: Replace both with specific CFLAGS* statements in the makefiles
159 __c_flags = $(if $(obj),$(call addtree,-I$(src)) -I$(obj)) \
160 $(call flags,_c_flags)
161 __a_flags = $(call flags,_a_flags)
162 __cpp_flags = $(call flags,_cpp_flags)
165 c_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
166 $(__c_flags) $(modkern_cflags) \
167 $(basename_flags) $(modname_flags)
169 a_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
170 $(__a_flags) $(modkern_aflags)
172 cpp_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
175 ld_flags = $(LDFLAGS) $(ldflags-y)
177 DTC_INCLUDE := $(srctree)/scripts/dtc/include-prefixes
179 dtc_cpp_flags = -Wp,-MD,$(depfile).pre.tmp -nostdinc \
180 $(addprefix -I,$(DTC_INCLUDE)) \
183 # Finds the multi-part object the current object will be linked into
184 modname-multi = $(sort $(foreach m,$(multi-used),\
185 $(if $(filter $(subst $(obj)/,,$*.o), $($(m:.o=-objs)) $($(m:.o=-y))),$(m:.o=))))
187 # Useful for describing the dependency of composite objects
189 # $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
191 $(foreach m, $(notdir $1), \
193 $(addprefix $(obj)/, $(foreach s, $3, $($(m:%$(strip $2)=%$(s)))))))
196 ifdef REGENERATE_PARSERS
199 # ---------------------------------------------------------------------------
200 LEX_PREFIX = $(if $(LEX_PREFIX_${baseprereq}),$(LEX_PREFIX_${baseprereq}),yy)
202 quiet_cmd_flex = LEX $@
203 cmd_flex = flex -o$@ -L -P $(LEX_PREFIX) $<
205 .PRECIOUS: $(src)/%.lex.c_shipped
206 $(src)/%.lex.c_shipped: $(src)/%.l
210 # ---------------------------------------------------------------------------
211 YACC_PREFIX = $(if $(YACC_PREFIX_${baseprereq}),$(YACC_PREFIX_${baseprereq}),yy)
213 quiet_cmd_bison = YACC $@
214 cmd_bison = bison -o$@ -t -l -p $(YACC_PREFIX) $<
216 .PRECIOUS: $(src)/%.tab.c_shipped
217 $(src)/%.tab.c_shipped: $(src)/%.y
220 quiet_cmd_bison_h = YACC $@
221 cmd_bison_h = bison -o/dev/null --defines=$@ -t -l -p $(YACC_PREFIX) $<
223 .PRECIOUS: $(src)/%.tab.h_shipped
224 $(src)/%.tab.h_shipped: $(src)/%.y
230 # ===========================================================================
232 quiet_cmd_shipped = SHIPPED $@
233 cmd_shipped = cat $< > $@
235 $(obj)/%: $(src)/%_shipped
238 # Commands useful for building a boot image
239 # ===========================================================================
243 # target: source(s) FORCE
244 # $(if_changed,ld/objcopy/gzip)
246 # and add target to extra-y so that we know we have to
247 # read in the saved command line
250 # ---------------------------------------------------------------------------
253 cmd_ld = $(LD) $(LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F)) \
254 $(filter-out FORCE,$^) -o $@
257 # ---------------------------------------------------------------------------
259 quiet_cmd_objcopy = OBJCOPY $@
260 cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
263 # ---------------------------------------------------------------------------
265 quiet_cmd_gzip = GZIP $@
266 cmd_gzip = (cat $(filter-out FORCE,$^) | gzip -n -f -9 > $@) || \
270 # ---------------------------------------------------------------------------
271 DTC ?= $(objtree)/scripts/dtc/dtc
273 # Disable noisy checks by default
274 ifeq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),)
275 DTC_FLAGS += -Wno-unit_address_vs_reg \
276 -Wno-simple_bus_reg \
277 -Wno-unit_address_format \
279 -Wno-pci_device_bus_num \
283 ifeq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),2)
284 DTC_FLAGS += -Wnode_name_chars_strict \
285 -Wproperty_name_chars_strict
288 DTC_FLAGS += $(DTC_FLAGS_$(basetarget))
290 # Generate an assembly file to wrap the output of the device tree compiler
291 quiet_cmd_dt_S_dtb= DTB $@
294 echo '\#include <asm-generic/vmlinux.lds.h>'; \
295 echo '.section .dtb.init.rodata,"a"'; \
296 echo '.balign STRUCT_ALIGNMENT'; \
297 echo '.global __dtb_$(subst -,_,$(*F))_begin'; \
298 echo '__dtb_$(subst -,_,$(*F))_begin:'; \
299 echo '.incbin "$<" '; \
300 echo '__dtb_$(subst -,_,$(*F))_end:'; \
301 echo '.global __dtb_$(subst -,_,$(*F))_end'; \
302 echo '.balign STRUCT_ALIGNMENT'; \
305 $(obj)/%.dtb.S: $(obj)/%.dtb
308 quiet_cmd_dtc = DTC $@
309 cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
310 $(CPP) $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
311 $(DTC) -O dtb -o $@ -b 0 \
312 $(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
313 -d $(depfile).dtc.tmp $(dtc-tmp) ; \
314 cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
316 $(obj)/%.dtb: $(src)/%.dts FORCE
317 $(call if_changed_dep,dtc)
319 dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
322 # ---------------------------------------------------------------------------
324 # Bzip2 and LZMA do not include size in file... so we have to fake that;
325 # append the size as a 32-bit littleendian number as gzip does.
326 size_append = printf $(shell \
329 fsize=$$(stat -c "%s" $$F); \
330 dec_size=$$(expr $$dec_size + $$fsize); \
332 printf "%08x\n" $$dec_size | \
333 sed 's/\(..\)/\1 /g' | { \
334 read ch0 ch1 ch2 ch3; \
335 for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \
336 printf '%s%03o' '\\' $$((0x$$ch)); \
341 quiet_cmd_bzip2 = BZIP2 $@
342 cmd_bzip2 = (cat $(filter-out FORCE,$^) | \
343 bzip2 -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
347 # ---------------------------------------------------------------------------
349 quiet_cmd_lzma = LZMA $@
350 cmd_lzma = (cat $(filter-out FORCE,$^) | \
351 lzma -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
354 quiet_cmd_lzo = LZO $@
355 cmd_lzo = (cat $(filter-out FORCE,$^) | \
356 lzop -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
359 quiet_cmd_lz4 = LZ4 $@
360 cmd_lz4 = (cat $(filter-out FORCE,$^) | \
361 lz4c -l -c1 stdin stdout && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
365 # ---------------------------------------------------------------------------
367 MKIMAGE := $(srctree)/scripts/mkuboot.sh
369 # SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
370 # the number of overrides in arch makefiles
371 UIMAGE_ARCH ?= $(SRCARCH)
372 UIMAGE_COMPRESSION ?= $(if $(2),$(2),none)
374 UIMAGE_TYPE ?= kernel
375 UIMAGE_LOADADDR ?= arch_must_set_this
376 UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)
377 UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)'
381 quiet_cmd_uimage = UIMAGE $(UIMAGE_OUT)
382 cmd_uimage = $(CONFIG_SHELL) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \
383 -C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \
385 -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \
386 -n $(UIMAGE_NAME) -d $(UIMAGE_IN) $(UIMAGE_OUT)
389 # ---------------------------------------------------------------------------
390 # Use xzkern to compress the kernel image and xzmisc to compress other things.
392 # xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage
393 # of the kernel decompressor. A BCJ filter is used if it is available for
394 # the target architecture. xzkern also appends uncompressed size of the data
395 # using size_append. The .xz format has the size information available at
396 # the end of the file too, but it's in more complex format and it's good to
397 # avoid changing the part of the boot code that reads the uncompressed size.
398 # Note that the bytes added by size_append will make the xz tool think that
399 # the file is corrupt. This is expected.
401 # xzmisc doesn't use size_append, so it can be used to create normal .xz
402 # files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very
403 # big dictionary would increase the memory usage too much in the multi-call
404 # decompression mode. A BCJ filter isn't used either.
405 quiet_cmd_xzkern = XZKERN $@
406 cmd_xzkern = (cat $(filter-out FORCE,$^) | \
407 sh $(srctree)/scripts/xz_wrap.sh && \
408 $(call size_append, $(filter-out FORCE,$^))) > $@ || \
411 quiet_cmd_xzmisc = XZMISC $@
412 cmd_xzmisc = (cat $(filter-out FORCE,$^) | \
413 xz --check=crc32 --lzma2=dict=1MiB) > $@ || \
417 # ---------------------------------------------------------------------------
419 # Default sed regexp - multiline due to syntax constraints
421 # Use [:space:] because LLVM's integrated assembler inserts <tab> around
422 # the .ascii directive whereas GCC keeps the <space> as-is.
424 's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \
425 /^->/{s:->#\(.*\):/* \1 */:; \
426 s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
430 # Use filechk to avoid rebuilds when a header changes, but the resulting file
432 define filechk_offsets
437 echo " * DO NOT MODIFY."; \
439 echo " * This file was generated by Kbuild"; \
442 sed -ne $(sed-offsets); \