Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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)
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
17obj-m := $(filter-out $(obj-y),$(obj-m))
18
19# Libraries are always collected in one lib file.
20# Filter out objects already built-in
21lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m)))
22
23# Determine modorder.
24# Unfortunately, we don't have information about ordering between -y
25# and -m subdirs. Just put -y's first.
26modorder := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m:.o=.ko))
27
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)))
35subdir-y += $(__subdir-y)
36__subdir-m := $(patsubst %/,%,$(filter %/, $(obj-m)))
37subdir-m += $(__subdir-m)
38obj-y := $(patsubst %/, %/built-in.a, $(obj-y))
39obj-m := $(filter-out %/, $(obj-m))
40
41# Subdirectories we need to descend into
42subdir-ym := $(sort $(subdir-y) $(subdir-m))
43
44# if $(foo-objs), $(foo-y), or $(foo-m) exists, foo.o is a composite object
45multi-used-y := $(sort $(foreach m,$(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))), $(m))))
46multi-used-m := $(sort $(foreach m,$(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))), $(m))))
47multi-used := $(multi-used-y) $(multi-used-m)
48single-used-m := $(sort $(filter-out $(multi-used-m),$(obj-m)))
49
50# $(subdir-obj-y) is the list of objects in $(obj-y) which uses dir/ to
51# tell kbuild to descend
52subdir-obj-y := $(filter %/built-in.a, $(obj-y))
53
54# Replace multi-part objects by their individual parts,
55# including built-in.a from subdirectories
56real-obj-y := $(foreach m, $(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m)))
57real-obj-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)))
58
59# DTB
60# If CONFIG_OF_ALL_DTBS is enabled, all DT blobs are built
61extra-y += $(dtb-y)
62extra-$(CONFIG_OF_ALL_DTBS) += $(dtb-)
63
64ifneq ($(CHECK_DTBS),)
65extra-y += $(patsubst %.dtb,%.dt.yaml, $(dtb-y))
66extra-$(CONFIG_OF_ALL_DTBS) += $(patsubst %.dtb,%.dt.yaml, $(dtb-))
67endif
68
69# Test self-contained headers
70
71# Wildcard searches in $(srctree)/$(src)/, but not in $(objtree)/$(obj)/.
72# Stale generated headers are often left over, so pattern matching should
73# be avoided. Please notice $(srctree)/$(src)/ and $(objtree)/$(obj) point
74# to the same location for in-tree building. So, header-test-pattern-y should
75# be used with care.
76header-test-y += $(filter-out $(header-test-), \
77 $(patsubst $(srctree)/$(src)/%, %, \
78 $(wildcard $(addprefix $(srctree)/$(src)/, \
79 $(header-test-pattern-y)))))
80
81extra-$(CONFIG_HEADER_TEST) += $(addsuffix .s, $(header-test-y) $(header-test-m))
82
83# Add subdir path
84
85extra-y := $(addprefix $(obj)/,$(extra-y))
86always := $(addprefix $(obj)/,$(always))
87targets := $(addprefix $(obj)/,$(targets))
88modorder := $(addprefix $(obj)/,$(modorder))
89obj-m := $(addprefix $(obj)/,$(obj-m))
90lib-y := $(addprefix $(obj)/,$(lib-y))
91subdir-obj-y := $(addprefix $(obj)/,$(subdir-obj-y))
92real-obj-y := $(addprefix $(obj)/,$(real-obj-y))
93real-obj-m := $(addprefix $(obj)/,$(real-obj-m))
94single-used-m := $(addprefix $(obj)/,$(single-used-m))
95multi-used-m := $(addprefix $(obj)/,$(multi-used-m))
96subdir-ym := $(addprefix $(obj)/,$(subdir-ym))
97
98# Finds the multi-part object the current object will be linked into.
99# If the object belongs to two or more multi-part objects, all of them are
100# concatenated with a colon separator.
101modname-multi = $(subst $(space),:,$(sort $(foreach m,$(multi-used),\
102 $(if $(filter $*.o, $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))),$(m:.o=)))))
103
104modname = $(if $(modname-multi),$(modname-multi),$(basetarget))
105
106# These flags are needed for modversions and compiling, so we define them here
107# $(modname_flags) defines KBUILD_MODNAME as the name of the module it will
108# end up in (or would, if it gets compiled in)
109name-fix = $(squote)$(quote)$(subst $(comma),_,$(subst -,_,$1))$(quote)$(squote)
110basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
111modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname))
112
113orig_c_flags = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) \
114 $(ccflags-y) $(CFLAGS_$(basetarget).o)
115_c_flags = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(orig_c_flags))
116orig_a_flags = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) \
117 $(asflags-y) $(AFLAGS_$(basetarget).o)
118_a_flags = $(filter-out $(AFLAGS_REMOVE_$(basetarget).o), $(orig_a_flags))
119_cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(@F))
120
121#
122# Enable gcov profiling flags for a file, directory or for all files depending
123# on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL
124# (in this order)
125#
126ifeq ($(CONFIG_GCOV_KERNEL),y)
127_c_flags += $(if $(patsubst n%,, \
128 $(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \
129 $(CFLAGS_GCOV))
130endif
131
132#
133# Enable address sanitizer flags for kernel except some files or directories
134# we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE)
135#
136ifeq ($(CONFIG_KASAN),y)
137_c_flags += $(if $(patsubst n%,, \
138 $(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \
139 $(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
140endif
141
142ifeq ($(CONFIG_UBSAN),y)
143_c_flags += $(if $(patsubst n%,, \
144 $(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
145 $(CFLAGS_UBSAN))
146endif
147
148ifeq ($(CONFIG_KCOV),y)
149_c_flags += $(if $(patsubst n%,, \
150 $(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \
151 $(CFLAGS_KCOV))
152endif
153
154# $(srctree)/$(src) for including checkin headers from generated source files
155# $(objtree)/$(obj) for including generated headers from checkin source files
156ifeq ($(KBUILD_EXTMOD),)
157ifdef building_out_of_srctree
158_c_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
159_a_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
160_cpp_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
161endif
162endif
163
164c_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
165 -include $(srctree)/include/linux/compiler_types.h \
166 $(_c_flags) $(modkern_cflags) \
167 $(basename_flags) $(modname_flags)
168
169a_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
170 $(_a_flags) $(modkern_aflags)
171
172cpp_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
173 $(_cpp_flags)
174
175ld_flags = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F))
176
177DTC_INCLUDE := $(srctree)/scripts/dtc/include-prefixes
178
179dtc_cpp_flags = -Wp,-MD,$(depfile).pre.tmp -nostdinc \
180 $(addprefix -I,$(DTC_INCLUDE)) \
181 -undef -D__DTS__
182
183# Useful for describing the dependency of composite objects
184# Usage:
185# $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
186define multi_depend
187$(foreach m, $(notdir $1), \
188 $(eval $(obj)/$m: \
189 $(addprefix $(obj)/, $(foreach s, $3, $($(m:%$(strip $2)=%$(s)))))))
190endef
191
192# LEX
193# ---------------------------------------------------------------------------
194quiet_cmd_flex = LEX $@
195 cmd_flex = $(LEX) -o$@ -L $<
196
197$(obj)/%.lex.c: $(src)/%.l FORCE
198 $(call if_changed,flex)
199
200# YACC
201# ---------------------------------------------------------------------------
202quiet_cmd_bison = YACC $@
203 cmd_bison = $(YACC) -o$@ -t -l $<
204
205$(obj)/%.tab.c: $(src)/%.y FORCE
206 $(call if_changed,bison)
207
208quiet_cmd_bison_h = YACC $@
209 cmd_bison_h = $(YACC) -o/dev/null --defines=$@ -t -l $<
210
211$(obj)/%.tab.h: $(src)/%.y FORCE
212 $(call if_changed,bison_h)
213
214# Shipped files
215# ===========================================================================
216
217quiet_cmd_shipped = SHIPPED $@
218cmd_shipped = cat $< > $@
219
220$(obj)/%: $(src)/%_shipped
221 $(call cmd,shipped)
222
223# Commands useful for building a boot image
224# ===========================================================================
225#
226# Use as following:
227#
228# target: source(s) FORCE
229# $(if_changed,ld/objcopy/gzip)
230#
231# and add target to extra-y so that we know we have to
232# read in the saved command line
233
234# Linking
235# ---------------------------------------------------------------------------
236
237quiet_cmd_ld = LD $@
238 cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@
239
240# Archive
241# ---------------------------------------------------------------------------
242
243quiet_cmd_ar = AR $@
244 cmd_ar = rm -f $@; $(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(real-prereqs)
245
246# Objcopy
247# ---------------------------------------------------------------------------
248
249quiet_cmd_objcopy = OBJCOPY $@
250cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
251
252# Gzip
253# ---------------------------------------------------------------------------
254
255quiet_cmd_gzip = GZIP $@
256 cmd_gzip = cat $(real-prereqs) | gzip -n -f -9 > $@
257
258# DTC
259# ---------------------------------------------------------------------------
260DTC ?= $(objtree)/scripts/dtc/dtc
261
262# Disable noisy checks by default
263ifeq ($(findstring 1,$(KBUILD_ENABLE_EXTRA_GCC_CHECKS)),)
264DTC_FLAGS += -Wno-unit_address_vs_reg \
265 -Wno-unit_address_format \
266 -Wno-avoid_unnecessary_addr_size \
267 -Wno-alias_paths \
268 -Wno-graph_child_address \
269 -Wno-simple_bus_reg \
270 -Wno-unique_unit_address \
271 -Wno-pci_device_reg
272endif
273
274ifneq ($(findstring 2,$(KBUILD_ENABLE_EXTRA_GCC_CHECKS)),)
275DTC_FLAGS += -Wnode_name_chars_strict \
276 -Wproperty_name_chars_strict
277endif
278
279DTC_FLAGS += $(DTC_FLAGS_$(basetarget))
280
281# Generate an assembly file to wrap the output of the device tree compiler
282quiet_cmd_dt_S_dtb= DTB $@
283cmd_dt_S_dtb= \
284{ \
285 echo '\#include <asm-generic/vmlinux.lds.h>'; \
286 echo '.section .dtb.init.rodata,"a"'; \
287 echo '.balign STRUCT_ALIGNMENT'; \
288 echo '.global __dtb_$(subst -,_,$(*F))_begin'; \
289 echo '__dtb_$(subst -,_,$(*F))_begin:'; \
290 echo '.incbin "$<" '; \
291 echo '__dtb_$(subst -,_,$(*F))_end:'; \
292 echo '.global __dtb_$(subst -,_,$(*F))_end'; \
293 echo '.balign STRUCT_ALIGNMENT'; \
294} > $@
295
296$(obj)/%.dtb.S: $(obj)/%.dtb FORCE
297 $(call if_changed,dt_S_dtb)
298
299quiet_cmd_dtc = DTC $@
300cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
301 $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
302 $(DTC) -O $(2) -o $@ -b 0 \
303 $(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
304 -d $(depfile).dtc.tmp $(dtc-tmp) ; \
305 cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
306
307$(obj)/%.dtb: $(src)/%.dts $(DTC) FORCE
308 $(call if_changed_dep,dtc,dtb)
309
310DT_CHECKER ?= dt-validate
311DT_BINDING_DIR := Documentation/devicetree/bindings
312DT_TMP_SCHEMA := $(objtree)/$(DT_BINDING_DIR)/processed-schema.yaml
313
314quiet_cmd_dtb_check = CHECK $@
315 cmd_dtb_check = $(DT_CHECKER) -u $(srctree)/$(DT_BINDING_DIR) -p $(DT_TMP_SCHEMA) $@ ;
316
317define rule_dtc_dt_yaml
318 $(call cmd_and_fixdep,dtc,yaml)
319 $(call cmd,dtb_check)
320endef
321
322$(obj)/%.dt.yaml: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE
323 $(call if_changed_rule,dtc_dt_yaml)
324
325dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
326
327# Bzip2
328# ---------------------------------------------------------------------------
329
330# Bzip2 and LZMA do not include size in file... so we have to fake that;
331# append the size as a 32-bit littleendian number as gzip does.
332size_append = printf $(shell \
333dec_size=0; \
334for F in $(real-prereqs); do \
335 fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F); \
336 dec_size=$$(expr $$dec_size + $$fsize); \
337done; \
338printf "%08x\n" $$dec_size | \
339 sed 's/\(..\)/\1 /g' | { \
340 read ch0 ch1 ch2 ch3; \
341 for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \
342 printf '%s%03o' '\\' $$((0x$$ch)); \
343 done; \
344 } \
345)
346
347quiet_cmd_bzip2 = BZIP2 $@
348 cmd_bzip2 = { cat $(real-prereqs) | bzip2 -9; $(size_append); } > $@
349
350# Lzma
351# ---------------------------------------------------------------------------
352
353quiet_cmd_lzma = LZMA $@
354 cmd_lzma = { cat $(real-prereqs) | lzma -9; $(size_append); } > $@
355
356quiet_cmd_lzo = LZO $@
357 cmd_lzo = { cat $(real-prereqs) | lzop -9; $(size_append); } > $@
358
359quiet_cmd_lz4 = LZ4 $@
360 cmd_lz4 = { cat $(real-prereqs) | lz4c -l -c1 stdin stdout; \
361 $(size_append); } > $@
362
363# U-Boot mkimage
364# ---------------------------------------------------------------------------
365
366MKIMAGE := $(srctree)/scripts/mkuboot.sh
367
368# SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
369# the number of overrides in arch makefiles
370UIMAGE_ARCH ?= $(SRCARCH)
371UIMAGE_COMPRESSION ?= $(if $(2),$(2),none)
372UIMAGE_OPTS-y ?=
373UIMAGE_TYPE ?= kernel
374UIMAGE_LOADADDR ?= arch_must_set_this
375UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)
376UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)'
377
378quiet_cmd_uimage = UIMAGE $@
379 cmd_uimage = $(CONFIG_SHELL) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \
380 -C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \
381 -T $(UIMAGE_TYPE) \
382 -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \
383 -n $(UIMAGE_NAME) -d $< $@
384
385# XZ
386# ---------------------------------------------------------------------------
387# Use xzkern to compress the kernel image and xzmisc to compress other things.
388#
389# xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage
390# of the kernel decompressor. A BCJ filter is used if it is available for
391# the target architecture. xzkern also appends uncompressed size of the data
392# using size_append. The .xz format has the size information available at
393# the end of the file too, but it's in more complex format and it's good to
394# avoid changing the part of the boot code that reads the uncompressed size.
395# Note that the bytes added by size_append will make the xz tool think that
396# the file is corrupt. This is expected.
397#
398# xzmisc doesn't use size_append, so it can be used to create normal .xz
399# files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very
400# big dictionary would increase the memory usage too much in the multi-call
401# decompression mode. A BCJ filter isn't used either.
402quiet_cmd_xzkern = XZKERN $@
403 cmd_xzkern = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \
404 $(size_append); } > $@
405
406quiet_cmd_xzmisc = XZMISC $@
407 cmd_xzmisc = cat $(real-prereqs) | xz --check=crc32 --lzma2=dict=1MiB > $@
408
409# ASM offsets
410# ---------------------------------------------------------------------------
411
412# Default sed regexp - multiline due to syntax constraints
413#
414# Use [:space:] because LLVM's integrated assembler inserts <tab> around
415# the .ascii directive whereas GCC keeps the <space> as-is.
416define sed-offsets
417 's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \
418 /^->/{s:->#\(.*\):/* \1 */:; \
419 s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
420 s:->::; p;}'
421endef
422
423# Use filechk to avoid rebuilds when a header changes, but the resulting file
424# does not
425define filechk_offsets
426 echo "#ifndef $2"; \
427 echo "#define $2"; \
428 echo "/*"; \
429 echo " * DO NOT MODIFY."; \
430 echo " *"; \
431 echo " * This file was generated by Kbuild"; \
432 echo " */"; \
433 echo ""; \
434 sed -ne $(sed-offsets) < $<; \
435 echo ""; \
436 echo "#endif"
437endef