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1# Backward compatibility
2asflags-y += $(EXTRA_AFLAGS)
3ccflags-y += $(EXTRA_CFLAGS)
4cppflags-y += $(EXTRA_CPPFLAGS)
5ldflags-y += $(EXTRA_LDFLAGS)
6
7#
8# flags that take effect in sub directories
9export KBUILD_SUBDIR_ASFLAGS := $(KBUILD_SUBDIR_ASFLAGS) $(subdir-asflags-y)
10export KBUILD_SUBDIR_CCFLAGS := $(KBUILD_SUBDIR_CCFLAGS) $(subdir-ccflags-y)
11
12# Figure out what we need to build from the various variables
13# ===========================================================================
14
15# When an object is listed to be built compiled-in and modular,
16# only build the compiled-in version
17
18obj-m := $(filter-out $(obj-y),$(obj-m))
19
20# Libraries are always collected in one lib file.
21# Filter out objects already built-in
22
23lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m)))
24
25
26# Handle objects in subdirs
27# ---------------------------------------------------------------------------
28# o if we encounter foo in $(obj-y), replace it by foo/built-in.o
29# and add the directory to the list of dirs to descend into: $(subdir-y)
30# o if we encounter foo/ in $(obj-m), remove it from $(obj-m)
31# and add the directory to the list of dirs to descend into: $(subdir-m)
32
33# Determine modorder.
34# Unfortunately, we don't have information about ordering between -y
35# and -m subdirs. Just put -y's first.
36modorder := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m:.o=.ko))
37
38__subdir-y := $(patsubst %/,%,$(filter %/, $(obj-y)))
39subdir-y += $(__subdir-y)
40__subdir-m := $(patsubst %/,%,$(filter %/, $(obj-m)))
41subdir-m += $(__subdir-m)
42obj-y := $(patsubst %/, %/built-in.o, $(obj-y))
43obj-m := $(filter-out %/, $(obj-m))
44
45# Subdirectories we need to descend into
46
47subdir-ym := $(sort $(subdir-y) $(subdir-m))
48
49# if $(foo-objs) exists, foo.o is a composite object
50multi-used-y := $(sort $(foreach m,$(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))), $(m))))
51multi-used-m := $(sort $(foreach m,$(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))), $(m))))
52multi-used := $(multi-used-y) $(multi-used-m)
53single-used-m := $(sort $(filter-out $(multi-used-m),$(obj-m)))
54
55# Build list of the parts of our composite objects, our composite
56# objects depend on those (obviously)
57multi-objs-y := $(foreach m, $(multi-used-y), $($(m:.o=-objs)) $($(m:.o=-y)))
58multi-objs-m := $(foreach m, $(multi-used-m), $($(m:.o=-objs)) $($(m:.o=-y)))
59multi-objs := $(multi-objs-y) $(multi-objs-m)
60
61# $(subdir-obj-y) is the list of objects in $(obj-y) which uses dir/ to
62# tell kbuild to descend
63subdir-obj-y := $(filter %/built-in.o, $(obj-y))
64
65# $(obj-dirs) is a list of directories that contain object files
66obj-dirs := $(dir $(multi-objs) $(obj-y))
67
68# Replace multi-part objects by their individual parts, look at local dir only
69real-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)
70real-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)))
71
72# Add subdir path
73
74extra-y := $(addprefix $(obj)/,$(extra-y))
75always := $(addprefix $(obj)/,$(always))
76targets := $(addprefix $(obj)/,$(targets))
77modorder := $(addprefix $(obj)/,$(modorder))
78obj-y := $(addprefix $(obj)/,$(obj-y))
79obj-m := $(addprefix $(obj)/,$(obj-m))
80lib-y := $(addprefix $(obj)/,$(lib-y))
81subdir-obj-y := $(addprefix $(obj)/,$(subdir-obj-y))
82real-objs-y := $(addprefix $(obj)/,$(real-objs-y))
83real-objs-m := $(addprefix $(obj)/,$(real-objs-m))
84single-used-m := $(addprefix $(obj)/,$(single-used-m))
85multi-used-y := $(addprefix $(obj)/,$(multi-used-y))
86multi-used-m := $(addprefix $(obj)/,$(multi-used-m))
87multi-objs-y := $(addprefix $(obj)/,$(multi-objs-y))
88multi-objs-m := $(addprefix $(obj)/,$(multi-objs-m))
89subdir-ym := $(addprefix $(obj)/,$(subdir-ym))
90obj-dirs := $(addprefix $(obj)/,$(obj-dirs))
91
92# These flags are needed for modversions and compiling, so we define them here
93# already
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# Note: Files that end up in two or more modules are compiled without the
97# KBUILD_MODNAME definition. The reason is that any made-up name would
98# differ in different configs.
99name-fix = $(squote)$(quote)$(subst $(comma),_,$(subst -,_,$1))$(quote)$(squote)
100basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
101modname_flags = $(if $(filter 1,$(words $(modname))),\
102 -DKBUILD_MODNAME=$(call name-fix,$(modname)))
103
104orig_c_flags = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(KBUILD_SUBDIR_CCFLAGS) \
105 $(ccflags-y) $(CFLAGS_$(basetarget).o)
106_c_flags = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(orig_c_flags))
107orig_a_flags = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(KBUILD_SUBDIR_ASFLAGS) \
108 $(asflags-y) $(AFLAGS_$(basetarget).o)
109_a_flags = $(filter-out $(AFLAGS_REMOVE_$(basetarget).o), $(orig_a_flags))
110_cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(@F))
111
112#
113# Enable gcov profiling flags for a file, directory or for all files depending
114# on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL
115# (in this order)
116#
117ifeq ($(CONFIG_GCOV_KERNEL),y)
118_c_flags += $(if $(patsubst n%,, \
119 $(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \
120 $(CFLAGS_GCOV))
121endif
122
123#
124# Enable address sanitizer flags for kernel except some files or directories
125# we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE)
126#
127ifeq ($(CONFIG_KASAN),y)
128_c_flags += $(if $(patsubst n%,, \
129 $(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \
130 $(CFLAGS_KASAN))
131endif
132
133ifeq ($(CONFIG_UBSAN),y)
134_c_flags += $(if $(patsubst n%,, \
135 $(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
136 $(CFLAGS_UBSAN))
137endif
138
139ifeq ($(CONFIG_KCOV),y)
140_c_flags += $(if $(patsubst n%,, \
141 $(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \
142 $(CFLAGS_KCOV))
143endif
144
145# If building the kernel in a separate objtree expand all occurrences
146# of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/').
147
148ifeq ($(KBUILD_SRC),)
149__c_flags = $(_c_flags)
150__a_flags = $(_a_flags)
151__cpp_flags = $(_cpp_flags)
152else
153
154# -I$(obj) locates generated .h files
155# $(call addtree,-I$(obj)) locates .h files in srctree, from generated .c files
156# and locates generated .h files
157# FIXME: Replace both with specific CFLAGS* statements in the makefiles
158__c_flags = $(if $(obj),-I$(srctree)/$(src) -I$(obj)) \
159 $(call flags,_c_flags)
160__a_flags = $(call flags,_a_flags)
161__cpp_flags = $(call flags,_cpp_flags)
162endif
163
164c_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
165 $(__c_flags) $(modkern_cflags) \
166 $(basename_flags) $(modname_flags)
167
168a_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
169 $(__a_flags) $(modkern_aflags)
170
171cpp_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
172 $(__cpp_flags)
173
174ld_flags = $(LDFLAGS) $(ldflags-y)
175
176dtc_cpp_flags = -Wp,-MD,$(depfile).pre.tmp -nostdinc \
177 -I$(srctree)/arch/$(SRCARCH)/boot/dts \
178 -I$(srctree)/arch/$(SRCARCH)/boot/dts/include \
179 -I$(srctree)/drivers/of/testcase-data \
180 -undef -D__DTS__
181
182# Finds the multi-part object the current object will be linked into
183modname-multi = $(sort $(foreach m,$(multi-used),\
184 $(if $(filter $(subst $(obj)/,,$*.o), $($(m:.o=-objs)) $($(m:.o=-y))),$(m:.o=))))
185
186# Useful for describing the dependency of composite objects
187# Usage:
188# $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
189define multi_depend
190$(foreach m, $(notdir $1), \
191 $(eval $(obj)/$m: \
192 $(addprefix $(obj)/, $(foreach s, $3, $($(m:%$(strip $2)=%$(s)))))))
193endef
194
195ifdef REGENERATE_PARSERS
196
197# GPERF
198# ---------------------------------------------------------------------------
199quiet_cmd_gperf = GPERF $@
200 cmd_gperf = gperf -t --output-file $@ -a -C -E -g -k 1,3,$$ -p -t $<
201
202.PRECIOUS: $(src)/%.hash.c_shipped
203$(src)/%.hash.c_shipped: $(src)/%.gperf
204 $(call cmd,gperf)
205
206# LEX
207# ---------------------------------------------------------------------------
208LEX_PREFIX = $(if $(LEX_PREFIX_${baseprereq}),$(LEX_PREFIX_${baseprereq}),yy)
209
210quiet_cmd_flex = LEX $@
211 cmd_flex = flex -o$@ -L -P $(LEX_PREFIX) $<
212
213.PRECIOUS: $(src)/%.lex.c_shipped
214$(src)/%.lex.c_shipped: $(src)/%.l
215 $(call cmd,flex)
216
217# YACC
218# ---------------------------------------------------------------------------
219YACC_PREFIX = $(if $(YACC_PREFIX_${baseprereq}),$(YACC_PREFIX_${baseprereq}),yy)
220
221quiet_cmd_bison = YACC $@
222 cmd_bison = bison -o$@ -t -l -p $(YACC_PREFIX) $<
223
224.PRECIOUS: $(src)/%.tab.c_shipped
225$(src)/%.tab.c_shipped: $(src)/%.y
226 $(call cmd,bison)
227
228quiet_cmd_bison_h = YACC $@
229 cmd_bison_h = bison -o/dev/null --defines=$@ -t -l -p $(YACC_PREFIX) $<
230
231.PRECIOUS: $(src)/%.tab.h_shipped
232$(src)/%.tab.h_shipped: $(src)/%.y
233 $(call cmd,bison_h)
234
235endif
236
237# Shipped files
238# ===========================================================================
239
240quiet_cmd_shipped = SHIPPED $@
241cmd_shipped = cat $< > $@
242
243$(obj)/%: $(src)/%_shipped
244 $(call cmd,shipped)
245
246# Commands useful for building a boot image
247# ===========================================================================
248#
249# Use as following:
250#
251# target: source(s) FORCE
252# $(if_changed,ld/objcopy/gzip)
253#
254# and add target to extra-y so that we know we have to
255# read in the saved command line
256
257# Linking
258# ---------------------------------------------------------------------------
259
260quiet_cmd_ld = LD $@
261cmd_ld = $(LD) $(LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F)) \
262 $(filter-out FORCE,$^) -o $@
263
264# Objcopy
265# ---------------------------------------------------------------------------
266
267quiet_cmd_objcopy = OBJCOPY $@
268cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
269
270# Gzip
271# ---------------------------------------------------------------------------
272
273quiet_cmd_gzip = GZIP $@
274cmd_gzip = (cat $(filter-out FORCE,$^) | gzip -n -f -9 > $@) || \
275 (rm -f $@ ; false)
276
277# DTC
278# ---------------------------------------------------------------------------
279DTC ?= $(objtree)/scripts/dtc/dtc
280
281# Disable noisy checks by default
282ifeq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),)
283DTC_FLAGS += -Wno-unit_address_vs_reg
284endif
285
286# Generate an assembly file to wrap the output of the device tree compiler
287quiet_cmd_dt_S_dtb= DTB $@
288cmd_dt_S_dtb= \
289( \
290 echo '\#include <asm-generic/vmlinux.lds.h>'; \
291 echo '.section .dtb.init.rodata,"a"'; \
292 echo '.balign STRUCT_ALIGNMENT'; \
293 echo '.global __dtb_$(*F)_begin'; \
294 echo '__dtb_$(*F)_begin:'; \
295 echo '.incbin "$<" '; \
296 echo '__dtb_$(*F)_end:'; \
297 echo '.global __dtb_$(*F)_end'; \
298 echo '.balign STRUCT_ALIGNMENT'; \
299) > $@
300
301$(obj)/%.dtb.S: $(obj)/%.dtb
302 $(call cmd,dt_S_dtb)
303
304quiet_cmd_dtc = DTC $@
305cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
306 $(CPP) $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
307 $(DTC) -O dtb -o $@ -b 0 \
308 -i $(dir $<) $(DTC_FLAGS) \
309 -d $(depfile).dtc.tmp $(dtc-tmp) ; \
310 cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
311
312$(obj)/%.dtb: $(src)/%.dts FORCE
313 $(call if_changed_dep,dtc)
314
315dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
316
317# Bzip2
318# ---------------------------------------------------------------------------
319
320# Bzip2 and LZMA do not include size in file... so we have to fake that;
321# append the size as a 32-bit littleendian number as gzip does.
322size_append = printf $(shell \
323dec_size=0; \
324for F in $1; do \
325 fsize=$$(stat -c "%s" $$F); \
326 dec_size=$$(expr $$dec_size + $$fsize); \
327done; \
328printf "%08x\n" $$dec_size | \
329 sed 's/\(..\)/\1 /g' | { \
330 read ch0 ch1 ch2 ch3; \
331 for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \
332 printf '%s%03o' '\\' $$((0x$$ch)); \
333 done; \
334 } \
335)
336
337quiet_cmd_bzip2 = BZIP2 $@
338cmd_bzip2 = (cat $(filter-out FORCE,$^) | \
339 bzip2 -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
340 (rm -f $@ ; false)
341
342# Lzma
343# ---------------------------------------------------------------------------
344
345quiet_cmd_lzma = LZMA $@
346cmd_lzma = (cat $(filter-out FORCE,$^) | \
347 lzma -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
348 (rm -f $@ ; false)
349
350quiet_cmd_lzo = LZO $@
351cmd_lzo = (cat $(filter-out FORCE,$^) | \
352 lzop -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
353 (rm -f $@ ; false)
354
355quiet_cmd_lz4 = LZ4 $@
356cmd_lz4 = (cat $(filter-out FORCE,$^) | \
357 lz4c -l -c1 stdin stdout && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
358 (rm -f $@ ; false)
359
360# U-Boot mkimage
361# ---------------------------------------------------------------------------
362
363MKIMAGE := $(srctree)/scripts/mkuboot.sh
364
365# SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
366# the number of overrides in arch makefiles
367UIMAGE_ARCH ?= $(SRCARCH)
368UIMAGE_COMPRESSION ?= $(if $(2),$(2),none)
369UIMAGE_OPTS-y ?=
370UIMAGE_TYPE ?= kernel
371UIMAGE_LOADADDR ?= arch_must_set_this
372UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)
373UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)'
374UIMAGE_IN ?= $<
375UIMAGE_OUT ?= $@
376
377quiet_cmd_uimage = UIMAGE $(UIMAGE_OUT)
378 cmd_uimage = $(CONFIG_SHELL) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \
379 -C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \
380 -T $(UIMAGE_TYPE) \
381 -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \
382 -n $(UIMAGE_NAME) -d $(UIMAGE_IN) $(UIMAGE_OUT)
383
384# XZ
385# ---------------------------------------------------------------------------
386# Use xzkern to compress the kernel image and xzmisc to compress other things.
387#
388# xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage
389# of the kernel decompressor. A BCJ filter is used if it is available for
390# the target architecture. xzkern also appends uncompressed size of the data
391# using size_append. The .xz format has the size information available at
392# the end of the file too, but it's in more complex format and it's good to
393# avoid changing the part of the boot code that reads the uncompressed size.
394# Note that the bytes added by size_append will make the xz tool think that
395# the file is corrupt. This is expected.
396#
397# xzmisc doesn't use size_append, so it can be used to create normal .xz
398# files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very
399# big dictionary would increase the memory usage too much in the multi-call
400# decompression mode. A BCJ filter isn't used either.
401quiet_cmd_xzkern = XZKERN $@
402cmd_xzkern = (cat $(filter-out FORCE,$^) | \
403 sh $(srctree)/scripts/xz_wrap.sh && \
404 $(call size_append, $(filter-out FORCE,$^))) > $@ || \
405 (rm -f $@ ; false)
406
407quiet_cmd_xzmisc = XZMISC $@
408cmd_xzmisc = (cat $(filter-out FORCE,$^) | \
409 xz --check=crc32 --lzma2=dict=1MiB) > $@ || \
410 (rm -f $@ ; false)
1# SPDX-License-Identifier: GPL-2.0
2# Backward compatibility
3asflags-y += $(EXTRA_AFLAGS)
4ccflags-y += $(EXTRA_CFLAGS)
5cppflags-y += $(EXTRA_CPPFLAGS)
6ldflags-y += $(EXTRA_LDFLAGS)
7
8# flags that take effect in current and sub directories
9KBUILD_AFLAGS += $(subdir-asflags-y)
10KBUILD_CFLAGS += $(subdir-ccflags-y)
11KBUILD_RUSTFLAGS += $(subdir-rustflags-y)
12
13# Figure out what we need to build from the various variables
14# ===========================================================================
15
16# When an object is listed to be built compiled-in and modular,
17# only build the compiled-in version
18obj-m := $(filter-out $(obj-y),$(obj-m))
19
20# Libraries are always collected in one lib file.
21# Filter out objects already built-in
22lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m)))
23
24# Subdirectories we need to descend into
25subdir-ym := $(sort $(subdir-y) $(subdir-m) \
26 $(patsubst %/,%, $(filter %/, $(obj-y) $(obj-m))))
27
28# Handle objects in subdirs:
29# - If we encounter foo in $(obj-y), replace it by foo/built-in.a and
30# foo/modules.order
31# - If we encounter foo/ in $(obj-m), replace it by foo/modules.order
32#
33# Generate modules.order to determine modorder. Unfortunately, we don't have
34# information about ordering between -y and -m subdirs. Just put -y's first.
35
36ifdef need-modorder
37obj-m := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m))
38else
39obj-m := $(filter-out %/, $(obj-m))
40endif
41
42ifdef need-builtin
43obj-y := $(patsubst %/, %/built-in.a, $(obj-y))
44else
45obj-y := $(filter-out %/, $(obj-y))
46endif
47
48ifdef need-dtbslist
49dtb-y += $(addsuffix /dtbs-list, $(subdir-ym))
50always-y += dtbs-list
51endif
52
53# Expand $(foo-objs) $(foo-y) etc. by replacing their individuals
54suffix-search = $(strip $(foreach s, $3, $($(1:%$(strip $2)=%$s))))
55# List composite targets that are constructed by combining other targets
56multi-search = $(sort $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $m)))
57# List primitive targets that are compiled from source files
58real-search = $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $(call suffix-search, $m, $2, $3), $m))
59
60# If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object
61multi-obj-y := $(call multi-search, $(obj-y), .o, -objs -y)
62multi-obj-m := $(call multi-search, $(obj-m), .o, -objs -y -m)
63multi-obj-ym := $(multi-obj-y) $(multi-obj-m)
64
65# Replace multi-part objects by their individual parts,
66# including built-in.a from subdirectories
67real-obj-y := $(call real-search, $(obj-y), .o, -objs -y)
68real-obj-m := $(call real-search, $(obj-m), .o, -objs -y -m)
69
70always-y += $(always-m)
71
72# hostprogs-always-y += foo
73# ... is a shorthand for
74# hostprogs += foo
75# always-y += foo
76hostprogs += $(hostprogs-always-y) $(hostprogs-always-m)
77always-y += $(hostprogs-always-y) $(hostprogs-always-m)
78
79# userprogs-always-y is likewise.
80userprogs += $(userprogs-always-y) $(userprogs-always-m)
81always-y += $(userprogs-always-y) $(userprogs-always-m)
82
83# DTB
84# If CONFIG_OF_ALL_DTBS is enabled, all DT blobs are built
85dtb-$(CONFIG_OF_ALL_DTBS) += $(dtb-)
86
87# Composite DTB (i.e. DTB constructed by overlay)
88multi-dtb-y := $(call multi-search, $(dtb-y), .dtb, -dtbs)
89# Primitive DTB compiled from *.dts
90real-dtb-y := $(call real-search, $(dtb-y), .dtb, -dtbs)
91# Base DTB that overlay is applied onto
92base-dtb-y := $(filter %.dtb, $(call real-search, $(multi-dtb-y), .dtb, -dtbs))
93
94always-y += $(dtb-y)
95
96# Add subdir path
97
98ifneq ($(obj),.)
99extra-y := $(addprefix $(obj)/,$(extra-y))
100always-y := $(addprefix $(obj)/,$(always-y))
101targets := $(addprefix $(obj)/,$(targets))
102obj-m := $(addprefix $(obj)/,$(obj-m))
103lib-y := $(addprefix $(obj)/,$(lib-y))
104real-obj-y := $(addprefix $(obj)/,$(real-obj-y))
105real-obj-m := $(addprefix $(obj)/,$(real-obj-m))
106multi-obj-m := $(addprefix $(obj)/, $(multi-obj-m))
107dtb-y := $(addprefix $(obj)/, $(dtb-y))
108multi-dtb-y := $(addprefix $(obj)/, $(multi-dtb-y))
109real-dtb-y := $(addprefix $(obj)/, $(real-dtb-y))
110subdir-ym := $(addprefix $(obj)/,$(subdir-ym))
111endif
112
113# Finds the multi-part object the current object will be linked into.
114# If the object belongs to two or more multi-part objects, list them all.
115modname-multi = $(sort $(foreach m,$(multi-obj-ym),\
116 $(if $(filter $*.o, $(call suffix-search, $m, .o, -objs -y -m)),$(m:.o=))))
117
118__modname = $(or $(modname-multi),$(basetarget))
119
120modname = $(subst $(space),:,$(__modname))
121modfile = $(addprefix $(obj)/,$(__modname))
122
123# target with $(obj)/ and its suffix stripped
124target-stem = $(basename $(patsubst $(obj)/%,%,$@))
125
126# These flags are needed for modversions and compiling, so we define them here
127# $(modname_flags) defines KBUILD_MODNAME as the name of the module it will
128# end up in (or would, if it gets compiled in)
129name-fix-token = $(subst $(comma),_,$(subst -,_,$1))
130name-fix = $(call stringify,$(call name-fix-token,$1))
131basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
132modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname)) \
133 -D__KBUILD_MODNAME=kmod_$(call name-fix-token,$(modname))
134modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile))
135
136_c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \
137 $(filter-out $(ccflags-remove-y), \
138 $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(ccflags-y)) \
139 $(CFLAGS_$(target-stem).o))
140_rust_flags = $(filter-out $(RUSTFLAGS_REMOVE_$(target-stem).o), \
141 $(filter-out $(rustflags-remove-y), \
142 $(KBUILD_RUSTFLAGS) $(rustflags-y)) \
143 $(RUSTFLAGS_$(target-stem).o))
144_a_flags = $(filter-out $(AFLAGS_REMOVE_$(target-stem).o), \
145 $(filter-out $(asflags-remove-y), \
146 $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(asflags-y)) \
147 $(AFLAGS_$(target-stem).o))
148_cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(target-stem).lds)
149
150#
151# Enable gcov profiling flags for a file, directory or for all files depending
152# on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL
153# (in this order)
154#
155ifeq ($(CONFIG_GCOV_KERNEL),y)
156_c_flags += $(if $(patsubst n%,, \
157 $(GCOV_PROFILE_$(target-stem).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \
158 $(CFLAGS_GCOV))
159endif
160
161#
162# Enable address sanitizer flags for kernel except some files or directories
163# we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE)
164#
165ifeq ($(CONFIG_KASAN),y)
166ifneq ($(CONFIG_KASAN_HW_TAGS),y)
167_c_flags += $(if $(patsubst n%,, \
168 $(KASAN_SANITIZE_$(target-stem).o)$(KASAN_SANITIZE)y), \
169 $(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
170endif
171endif
172
173ifeq ($(CONFIG_KMSAN),y)
174_c_flags += $(if $(patsubst n%,, \
175 $(KMSAN_SANITIZE_$(target-stem).o)$(KMSAN_SANITIZE)y), \
176 $(CFLAGS_KMSAN))
177_c_flags += $(if $(patsubst n%,, \
178 $(KMSAN_ENABLE_CHECKS_$(target-stem).o)$(KMSAN_ENABLE_CHECKS)y), \
179 , -mllvm -msan-disable-checks=1)
180endif
181
182ifeq ($(CONFIG_UBSAN),y)
183_c_flags += $(if $(patsubst n%,, \
184 $(UBSAN_SANITIZE_$(target-stem).o)$(UBSAN_SANITIZE)y), \
185 $(CFLAGS_UBSAN))
186_c_flags += $(if $(patsubst n%,, \
187 $(UBSAN_SIGNED_WRAP_$(target-stem).o)$(UBSAN_SANITIZE_$(target-stem).o)$(UBSAN_SIGNED_WRAP)$(UBSAN_SANITIZE)y), \
188 $(CFLAGS_UBSAN_SIGNED_WRAP))
189endif
190
191ifeq ($(CONFIG_KCOV),y)
192_c_flags += $(if $(patsubst n%,, \
193 $(KCOV_INSTRUMENT_$(target-stem).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \
194 $(CFLAGS_KCOV))
195endif
196
197#
198# Enable KCSAN flags except some files or directories we don't want to check
199# (depends on variables KCSAN_SANITIZE_obj.o, KCSAN_SANITIZE)
200#
201ifeq ($(CONFIG_KCSAN),y)
202_c_flags += $(if $(patsubst n%,, \
203 $(KCSAN_SANITIZE_$(target-stem).o)$(KCSAN_SANITIZE)y), \
204 $(CFLAGS_KCSAN))
205# Some uninstrumented files provide implied barriers required to avoid false
206# positives: set KCSAN_INSTRUMENT_BARRIERS for barrier instrumentation only.
207_c_flags += $(if $(patsubst n%,, \
208 $(KCSAN_INSTRUMENT_BARRIERS_$(target-stem).o)$(KCSAN_INSTRUMENT_BARRIERS)n), \
209 -D__KCSAN_INSTRUMENT_BARRIERS__)
210endif
211
212# $(srctree)/$(src) for including checkin headers from generated source files
213# $(objtree)/$(obj) for including generated headers from checkin source files
214ifeq ($(KBUILD_EXTMOD),)
215ifdef building_out_of_srctree
216_c_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
217_a_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
218_cpp_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
219endif
220endif
221
222part-of-module = $(if $(filter $(basename $@).o, $(real-obj-m)),y)
223quiet_modtag = $(if $(part-of-module),[M], )
224
225modkern_cflags = \
226 $(if $(part-of-module), \
227 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
228 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL) $(modfile_flags))
229
230modkern_rustflags = \
231 $(if $(part-of-module), \
232 $(KBUILD_RUSTFLAGS_MODULE) $(RUSTFLAGS_MODULE), \
233 $(KBUILD_RUSTFLAGS_KERNEL) $(RUSTFLAGS_KERNEL))
234
235modkern_aflags = $(if $(part-of-module), \
236 $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE), \
237 $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL))
238
239c_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
240 -include $(srctree)/include/linux/compiler_types.h \
241 $(_c_flags) $(modkern_cflags) \
242 $(basename_flags) $(modname_flags)
243
244rust_flags = $(_rust_flags) $(modkern_rustflags) @$(objtree)/include/generated/rustc_cfg
245
246a_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
247 $(_a_flags) $(modkern_aflags)
248
249cpp_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
250 $(_cpp_flags)
251
252ld_flags = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F))
253
254DTC_INCLUDE := $(srctree)/scripts/dtc/include-prefixes
255
256dtc_cpp_flags = -Wp,-MMD,$(depfile).pre.tmp -nostdinc \
257 $(addprefix -I,$(DTC_INCLUDE)) \
258 -undef -D__DTS__
259
260ifdef CONFIG_OBJTOOL
261
262objtool := $(objtree)/tools/objtool/objtool
263
264objtool-args-$(CONFIG_HAVE_JUMP_LABEL_HACK) += --hacks=jump_label
265objtool-args-$(CONFIG_HAVE_NOINSTR_HACK) += --hacks=noinstr
266objtool-args-$(CONFIG_MITIGATION_CALL_DEPTH_TRACKING) += --hacks=skylake
267objtool-args-$(CONFIG_X86_KERNEL_IBT) += --ibt
268objtool-args-$(CONFIG_FINEIBT) += --cfi
269objtool-args-$(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL) += --mcount
270ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
271objtool-args-$(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT) += --mnop
272endif
273objtool-args-$(CONFIG_UNWINDER_ORC) += --orc
274objtool-args-$(CONFIG_MITIGATION_RETPOLINE) += --retpoline
275objtool-args-$(CONFIG_MITIGATION_RETHUNK) += --rethunk
276objtool-args-$(CONFIG_MITIGATION_SLS) += --sls
277objtool-args-$(CONFIG_STACK_VALIDATION) += --stackval
278objtool-args-$(CONFIG_HAVE_STATIC_CALL_INLINE) += --static-call
279objtool-args-$(CONFIG_HAVE_UACCESS_VALIDATION) += --uaccess
280objtool-args-$(CONFIG_GCOV_KERNEL) += --no-unreachable
281objtool-args-$(CONFIG_PREFIX_SYMBOLS) += --prefix=$(CONFIG_FUNCTION_PADDING_BYTES)
282
283objtool-args = $(objtool-args-y) \
284 $(if $(delay-objtool), --link) \
285 $(if $(part-of-module), --module)
286
287delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT))
288
289cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool-args) $@)
290cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
291
292endif # CONFIG_OBJTOOL
293
294# Useful for describing the dependency of composite objects
295# Usage:
296# $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
297define multi_depend
298$(foreach m, $1, \
299 $(eval $m: \
300 $(addprefix $(obj)/, $(call suffix-search, $(patsubst $(obj)/%,%,$m), $2, $3))))
301endef
302
303# Copy a file
304# ===========================================================================
305# 'cp' preserves permissions. If you use it to copy a file in read-only srctree,
306# the copy would be read-only as well, leading to an error when executing the
307# rule next time. Use 'cat' instead in order to generate a writable file.
308quiet_cmd_copy = COPY $@
309 cmd_copy = cat $< > $@
310
311$(obj)/%: $(src)/%_shipped
312 $(call cmd,copy)
313
314# Commands useful for building a boot image
315# ===========================================================================
316#
317# Use as following:
318#
319# target: source(s) FORCE
320# $(if_changed,ld/objcopy/gzip)
321#
322# and add target to 'targets' so that we know we have to
323# read in the saved command line
324
325# Linking
326# ---------------------------------------------------------------------------
327
328quiet_cmd_ld = LD $@
329 cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@
330
331# Archive
332# ---------------------------------------------------------------------------
333
334quiet_cmd_ar = AR $@
335 cmd_ar = rm -f $@; $(AR) cDPrsT $@ $(real-prereqs)
336
337# Objcopy
338# ---------------------------------------------------------------------------
339
340quiet_cmd_objcopy = OBJCOPY $@
341cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
342
343# Gzip
344# ---------------------------------------------------------------------------
345
346quiet_cmd_gzip = GZIP $@
347 cmd_gzip = cat $(real-prereqs) | $(KGZIP) -n -f -9 > $@
348
349# DTC
350# ---------------------------------------------------------------------------
351DTC ?= $(objtree)/scripts/dtc/dtc
352DTC_FLAGS += \
353 -Wno-unique_unit_address
354
355# Disable noisy checks by default
356ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
357DTC_FLAGS += -Wno-unit_address_vs_reg \
358 -Wno-avoid_unnecessary_addr_size \
359 -Wno-alias_paths \
360 -Wno-graph_child_address \
361 -Wno-simple_bus_reg
362else
363DTC_FLAGS += \
364 -Wunique_unit_address_if_enabled
365endif
366
367ifneq ($(findstring 2,$(KBUILD_EXTRA_WARN)),)
368DTC_FLAGS += -Wnode_name_chars_strict \
369 -Wproperty_name_chars_strict \
370 -Wunique_unit_address
371endif
372
373DTC_FLAGS += $(DTC_FLAGS_$(target-stem))
374
375# Set -@ if the target is a base DTB that overlay is applied onto
376DTC_FLAGS += $(if $(filter $(patsubst $(obj)/%,%,$@), $(base-dtb-y)), -@)
377
378# Generate an assembly file to wrap the output of the device tree compiler
379quiet_cmd_wrap_S_dtb = WRAP $@
380 cmd_wrap_S_dtb = { \
381 symbase=__$(patsubst .%,%,$(suffix $<))_$(subst -,_,$(notdir $*)); \
382 echo '\#include <asm-generic/vmlinux.lds.h>'; \
383 echo '.section .dtb.init.rodata,"a"'; \
384 echo '.balign STRUCT_ALIGNMENT'; \
385 echo ".global $${symbase}_begin"; \
386 echo "$${symbase}_begin:"; \
387 echo '.incbin "$<" '; \
388 echo ".global $${symbase}_end"; \
389 echo "$${symbase}_end:"; \
390 echo '.balign STRUCT_ALIGNMENT'; \
391 } > $@
392
393$(obj)/%.dtb.S: $(obj)/%.dtb FORCE
394 $(call if_changed,wrap_S_dtb)
395
396$(obj)/%.dtbo.S: $(obj)/%.dtbo FORCE
397 $(call if_changed,wrap_S_dtb)
398
399quiet_cmd_dtc = DTC $@
400cmd_dtc = $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
401 $(DTC) -o $@ -b 0 \
402 $(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
403 -d $(depfile).dtc.tmp $(dtc-tmp) ; \
404 cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
405
406quiet_cmd_fdtoverlay = DTOVL $@
407 cmd_fdtoverlay = $(objtree)/scripts/dtc/fdtoverlay -o $@ -i $(real-prereqs)
408
409$(multi-dtb-y): FORCE
410 $(call if_changed,fdtoverlay)
411$(call multi_depend, $(multi-dtb-y), .dtb, -dtbs)
412
413ifneq ($(CHECK_DTBS)$(CHECK_DT_BINDING),)
414DT_CHECKER ?= dt-validate
415DT_CHECKER_FLAGS ?= $(if $(DT_SCHEMA_FILES),-l $(DT_SCHEMA_FILES),-m)
416DT_BINDING_DIR := Documentation/devicetree/bindings
417DT_TMP_SCHEMA := $(objtree)/$(DT_BINDING_DIR)/processed-schema.json
418
419quiet_cmd_dtb = DTC_CHK $@
420 cmd_dtb = $(cmd_dtc) ; $(DT_CHECKER) $(DT_CHECKER_FLAGS) -u $(srctree)/$(DT_BINDING_DIR) -p $(DT_TMP_SCHEMA) $@ || true
421else
422quiet_cmd_dtb = $(quiet_cmd_dtc)
423 cmd_dtb = $(cmd_dtc)
424endif
425
426$(obj)/%.dtb: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE
427 $(call if_changed_dep,dtb)
428
429$(obj)/%.dtbo: $(src)/%.dtso $(DTC) FORCE
430 $(call if_changed_dep,dtc)
431
432dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
433
434# Bzip2
435# ---------------------------------------------------------------------------
436
437# Bzip2 and LZMA do not include size in file... so we have to fake that;
438# append the size as a 32-bit littleendian number as gzip does.
439size_append = printf $(shell \
440dec_size=0; \
441for F in $(real-prereqs); do \
442 fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F); \
443 dec_size=$$(expr $$dec_size + $$fsize); \
444done; \
445printf "%08x\n" $$dec_size | \
446 sed 's/\(..\)/\1 /g' | { \
447 read ch0 ch1 ch2 ch3; \
448 for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \
449 printf '%s%03o' '\\' $$((0x$$ch)); \
450 done; \
451 } \
452)
453
454quiet_cmd_file_size = GEN $@
455 cmd_file_size = $(size_append) > $@
456
457quiet_cmd_bzip2 = BZIP2 $@
458 cmd_bzip2 = cat $(real-prereqs) | $(KBZIP2) -9 > $@
459
460quiet_cmd_bzip2_with_size = BZIP2 $@
461 cmd_bzip2_with_size = { cat $(real-prereqs) | $(KBZIP2) -9; $(size_append); } > $@
462
463# Lzma
464# ---------------------------------------------------------------------------
465
466quiet_cmd_lzma = LZMA $@
467 cmd_lzma = cat $(real-prereqs) | $(LZMA) -9 > $@
468
469quiet_cmd_lzma_with_size = LZMA $@
470 cmd_lzma_with_size = { cat $(real-prereqs) | $(LZMA) -9; $(size_append); } > $@
471
472quiet_cmd_lzo = LZO $@
473 cmd_lzo = cat $(real-prereqs) | $(KLZOP) -9 > $@
474
475quiet_cmd_lzo_with_size = LZO $@
476 cmd_lzo_with_size = { cat $(real-prereqs) | $(KLZOP) -9; $(size_append); } > $@
477
478quiet_cmd_lz4 = LZ4 $@
479 cmd_lz4 = cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout > $@
480
481quiet_cmd_lz4_with_size = LZ4 $@
482 cmd_lz4_with_size = { cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout; \
483 $(size_append); } > $@
484
485# U-Boot mkimage
486# ---------------------------------------------------------------------------
487
488MKIMAGE := $(srctree)/scripts/mkuboot.sh
489
490# SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
491# the number of overrides in arch makefiles
492UIMAGE_ARCH ?= $(SRCARCH)
493UIMAGE_COMPRESSION ?= $(or $(2),none)
494UIMAGE_OPTS-y ?=
495UIMAGE_TYPE ?= kernel
496UIMAGE_LOADADDR ?= arch_must_set_this
497UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)
498UIMAGE_NAME ?= Linux-$(KERNELRELEASE)
499
500quiet_cmd_uimage = UIMAGE $@
501 cmd_uimage = $(BASH) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \
502 -C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \
503 -T $(UIMAGE_TYPE) \
504 -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \
505 -n '$(UIMAGE_NAME)' -d $< $@
506
507# XZ
508# ---------------------------------------------------------------------------
509# Use xzkern to compress the kernel image and xzmisc to compress other things.
510#
511# xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage
512# of the kernel decompressor. A BCJ filter is used if it is available for
513# the target architecture. xzkern also appends uncompressed size of the data
514# using size_append. The .xz format has the size information available at
515# the end of the file too, but it's in more complex format and it's good to
516# avoid changing the part of the boot code that reads the uncompressed size.
517# Note that the bytes added by size_append will make the xz tool think that
518# the file is corrupt. This is expected.
519#
520# xzmisc doesn't use size_append, so it can be used to create normal .xz
521# files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very
522# big dictionary would increase the memory usage too much in the multi-call
523# decompression mode. A BCJ filter isn't used either.
524quiet_cmd_xzkern = XZKERN $@
525 cmd_xzkern = cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh > $@
526
527quiet_cmd_xzkern_with_size = XZKERN $@
528 cmd_xzkern_with_size = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \
529 $(size_append); } > $@
530
531quiet_cmd_xzmisc = XZMISC $@
532 cmd_xzmisc = cat $(real-prereqs) | $(XZ) --check=crc32 --lzma2=dict=1MiB > $@
533
534# ZSTD
535# ---------------------------------------------------------------------------
536# Appends the uncompressed size of the data using size_append. The .zst
537# format has the size information available at the beginning of the file too,
538# but it's in a more complex format and it's good to avoid changing the part
539# of the boot code that reads the uncompressed size.
540#
541# Note that the bytes added by size_append will make the zstd tool think that
542# the file is corrupt. This is expected.
543#
544# zstd uses a maximum window size of 8 MB. zstd22 uses a maximum window size of
545# 128 MB. zstd22 is used for kernel compression because it is decompressed in a
546# single pass, so zstd doesn't need to allocate a window buffer. When streaming
547# decompression is used, like initramfs decompression, zstd22 should likely not
548# be used because it would require zstd to allocate a 128 MB buffer.
549
550quiet_cmd_zstd = ZSTD $@
551 cmd_zstd = cat $(real-prereqs) | $(ZSTD) -19 > $@
552
553quiet_cmd_zstd22 = ZSTD22 $@
554 cmd_zstd22 = cat $(real-prereqs) | $(ZSTD) -22 --ultra > $@
555
556quiet_cmd_zstd22_with_size = ZSTD22 $@
557 cmd_zstd22_with_size = { cat $(real-prereqs) | $(ZSTD) -22 --ultra; $(size_append); } > $@
558
559# ASM offsets
560# ---------------------------------------------------------------------------
561
562# Default sed regexp - multiline due to syntax constraints
563#
564# Use [:space:] because LLVM's integrated assembler inserts <tab> around
565# the .ascii directive whereas GCC keeps the <space> as-is.
566define sed-offsets
567 's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \
568 /^->/{s:->#\(.*\):/* \1 */:; \
569 s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
570 s:->::; p;}'
571endef
572
573# Use filechk to avoid rebuilds when a header changes, but the resulting file
574# does not
575define filechk_offsets
576 echo "#ifndef $2"; \
577 echo "#define $2"; \
578 echo "/*"; \
579 echo " * DO NOT MODIFY."; \
580 echo " *"; \
581 echo " * This file was generated by Kbuild"; \
582 echo " */"; \
583 echo ""; \
584 sed -ne $(sed-offsets) < $<; \
585 echo ""; \
586 echo "#endif"
587endef