1# ==========================================================================
2# Building
3# ==========================================================================
4
5src := $(obj)
6
7PHONY := __build
8__build:
9
10# Init all relevant variables used in kbuild files so
11# 1) they have correct type
12# 2) they do not inherit any value from the environment
13obj-y :=
14obj-m :=
15lib-y :=
16lib-m :=
17always :=
18targets :=
19subdir-y :=
20subdir-m :=
21EXTRA_AFLAGS   :=
22EXTRA_CFLAGS   :=
23EXTRA_CPPFLAGS :=
24EXTRA_LDFLAGS  :=
25asflags-y  :=
26ccflags-y  :=
27cppflags-y :=
28ldflags-y  :=
29
30subdir-asflags-y :=
31subdir-ccflags-y :=
32
33# Read auto.conf if it exists, otherwise ignore
34-include include/config/auto.conf
35
36include scripts/Kbuild.include
37
38# For backward compatibility check that these variables do not change
39save-cflags := $(CFLAGS)
40
41# The filename Kbuild has precedence over Makefile
42kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
43kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
44include $(kbuild-file)
45
46# If the save-* variables changed error out
47ifeq ($(KBUILD_NOPEDANTIC),)
48        ifneq ("$(save-cflags)","$(CFLAGS)")
49                $(error CFLAGS was changed in "$(kbuild-file)". Fix it to use EXTRA_CFLAGS)
50        endif
51endif
52include scripts/Makefile.lib
53
54ifdef host-progs
55ifneq ($(hostprogs-y),$(host-progs))
56$(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
57hostprogs-y += $(host-progs)
58endif
59endif
60
61# Do not include host rules unless needed
62ifneq ($(hostprogs-y)$(hostprogs-m),)
63include scripts/Makefile.host
64endif
65
66ifneq ($(KBUILD_SRC),)
67# Create output directory if not already present
68_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
69
70# Create directories for object files if directory does not exist
71# Needed when obj-y := dir/file.o syntax is used
72_dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))
73endif
74
75ifndef obj
76$(warning kbuild: Makefile.build is included improperly)
77endif
78
79# ===========================================================================
80
81ifneq ($(strip $(lib-y) $(lib-m) $(lib-n) $(lib-)),)
82lib-target := $(obj)/lib.a
83endif
84
85ifneq ($(strip $(obj-y) $(obj-m) $(obj-n) $(obj-) $(subdir-m) $(lib-target)),)
86builtin-target := $(obj)/built-in.o
87endif
88
89modorder-target := $(obj)/modules.order
90
91# We keep a list of all modules in $(MODVERDIR)
92
93__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
94	 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
95	 $(subdir-ym) $(always)
96	@:
97
98# Linus' kernel sanity checking tool
99ifneq ($(KBUILD_CHECKSRC),0)
100  ifeq ($(KBUILD_CHECKSRC),2)
101    quiet_cmd_force_checksrc = CHECK   $<
102          cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
103  else
104      quiet_cmd_checksrc     = CHECK   $<
105            cmd_checksrc     = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
106  endif
107endif
108
109# Do section mismatch analysis for each module/built-in.o
110ifdef CONFIG_DEBUG_SECTION_MISMATCH
111  cmd_secanalysis = ; scripts/mod/modpost $@
112endif
113
114# Compile C sources (.c)
115# ---------------------------------------------------------------------------
116
117# Default is built-in, unless we know otherwise
118modkern_cflags =                                          \
119	$(if $(part-of-module),                           \
120		$(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
121		$(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
122quiet_modtag := $(empty)   $(empty)
123
124$(real-objs-m)        : part-of-module := y
125$(real-objs-m:.o=.i)  : part-of-module := y
126$(real-objs-m:.o=.s)  : part-of-module := y
127$(real-objs-m:.o=.lst): part-of-module := y
128
129$(real-objs-m)        : quiet_modtag := [M]
130$(real-objs-m:.o=.i)  : quiet_modtag := [M]
131$(real-objs-m:.o=.s)  : quiet_modtag := [M]
132$(real-objs-m:.o=.lst): quiet_modtag := [M]
133
134$(obj-m)              : quiet_modtag := [M]
135
136# Default for not multi-part modules
137modname = $(basetarget)
138
139$(multi-objs-m)         : modname = $(modname-multi)
140$(multi-objs-m:.o=.i)   : modname = $(modname-multi)
141$(multi-objs-m:.o=.s)   : modname = $(modname-multi)
142$(multi-objs-m:.o=.lst) : modname = $(modname-multi)
143$(multi-objs-y)         : modname = $(modname-multi)
144$(multi-objs-y:.o=.i)   : modname = $(modname-multi)
145$(multi-objs-y:.o=.s)   : modname = $(modname-multi)
146$(multi-objs-y:.o=.lst) : modname = $(modname-multi)
147
148quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
149cmd_cc_s_c       = $(CC) $(c_flags) -fverbose-asm -S -o $@ $<
150
151$(obj)/%.s: $(src)/%.c FORCE
152	$(call if_changed_dep,cc_s_c)
153
154quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
155cmd_cc_i_c       = $(CPP) $(c_flags)   -o $@ $<
156
157$(obj)/%.i: $(src)/%.c FORCE
158	$(call if_changed_dep,cc_i_c)
159
160cmd_gensymtypes =                                                           \
161    $(CPP) -D__GENKSYMS__ $(c_flags) $< |                                   \
162    $(GENKSYMS) $(if $(1), -T $(2)) -a $(ARCH)                              \
163     $(if $(KBUILD_PRESERVE),-p)                                            \
164     -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
165
166quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
167cmd_cc_symtypes_c =                                                         \
168    set -e;                                                                 \
169    $(call cmd_gensymtypes,true,$@) >/dev/null;                             \
170    test -s $@ || rm -f $@
171
172$(obj)/%.symtypes : $(src)/%.c FORCE
173	$(call cmd,cc_symtypes_c)
174
175# C (.c) files
176# The C file is compiled and updated dependency information is generated.
177# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
178
179quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@
180
181ifndef CONFIG_MODVERSIONS
182cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
183
184else
185# When module versioning is enabled the following steps are executed:
186# o compile a .tmp_<file>.o from <file>.c
187# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
188#   not export symbols, we just rename .tmp_<file>.o to <file>.o and
189#   are done.
190# o otherwise, we calculate symbol versions using the good old
191#   genksyms on the preprocessed source and postprocess them in a way
192#   that they are usable as a linker script
193# o generate <file>.o from .tmp_<file>.o using the linker to
194#   replace the unresolved symbols __crc_exported_symbol with
195#   the actual value of the checksum generated by genksyms
196
197cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
198cmd_modversions =								\
199	if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then		\
200		$(call cmd_gensymtypes,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))	\
201		    > $(@D)/.tmp_$(@F:.o=.ver);					\
202										\
203		$(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) 			\
204			-T $(@D)/.tmp_$(@F:.o=.ver);				\
205		rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver);		\
206	else									\
207		mv -f $(@D)/.tmp_$(@F) $@;					\
208	fi;
209endif
210
211ifdef CONFIG_FTRACE_MCOUNT_RECORD
212cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
213	"$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
214	"$(if $(CONFIG_64BIT),64,32)" \
215	"$(OBJDUMP)" "$(OBJCOPY)" "$(CC)" "$(LD)" "$(NM)" "$(RM)" "$(MV)" \
216	"$(if $(part-of-module),1,0)" "$(@)";
217endif
218
219define rule_cc_o_c
220	$(call echo-cmd,checksrc) $(cmd_checksrc)			  \
221	$(call echo-cmd,cc_o_c) $(cmd_cc_o_c);				  \
222	$(cmd_modversions)						  \
223	$(call echo-cmd,record_mcount)					  \
224	$(cmd_record_mcount)						  \
225	scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' >    \
226	                                              $(dot-target).tmp;  \
227	rm -f $(depfile);						  \
228	mv -f $(dot-target).tmp $(dot-target).cmd
229endef
230
231# Built-in and composite module parts
232$(obj)/%.o: $(src)/%.c FORCE
233	$(call cmd,force_checksrc)
234	$(call if_changed_rule,cc_o_c)
235
236# Single-part modules are special since we need to mark them in $(MODVERDIR)
237
238$(single-used-m): $(obj)/%.o: $(src)/%.c FORCE
239	$(call cmd,force_checksrc)
240	$(call if_changed_rule,cc_o_c)
241	@{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
242
243quiet_cmd_cc_lst_c = MKLST   $@
244      cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
245		     $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
246				     System.map $(OBJDUMP) > $@
247
248$(obj)/%.lst: $(src)/%.c FORCE
249	$(call if_changed_dep,cc_lst_c)
250
251# Compile assembler sources (.S)
252# ---------------------------------------------------------------------------
253
254modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
255
256$(real-objs-m)      : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
257$(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
258
259quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
260cmd_as_s_S       = $(CPP) $(a_flags)   -o $@ $< 
261
262$(obj)/%.s: $(src)/%.S FORCE
263	$(call if_changed_dep,as_s_S)
264
265quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
266cmd_as_o_S       = $(CC) $(a_flags) -c -o $@ $<
267
268$(obj)/%.o: $(src)/%.S FORCE
269	$(call if_changed_dep,as_o_S)
270
271targets += $(real-objs-y) $(real-objs-m) $(lib-y)
272targets += $(extra-y) $(MAKECMDGOALS) $(always)
273
274# Linker scripts preprocessor (.lds.S -> .lds)
275# ---------------------------------------------------------------------------
276quiet_cmd_cpp_lds_S = LDS     $@
277      cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
278	                     -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
279
280$(obj)/%.lds: $(src)/%.lds.S FORCE
281	$(call if_changed_dep,cpp_lds_S)
282
283# Build the compiled-in targets
284# ---------------------------------------------------------------------------
285
286# To build objects in subdirs, we need to descend into the directories
287$(sort $(subdir-obj-y)): $(subdir-ym) ;
288
289#
290# Rule to compile a set of .o files into one .o file
291#
292ifdef builtin-target
293quiet_cmd_link_o_target = LD      $@
294# If the list of objects to link is empty, just create an empty built-in.o
295cmd_link_o_target = $(if $(strip $(obj-y)),\
296		      $(LD) $(ld_flags) -r -o $@ $(filter $(obj-y), $^) \
297		      $(cmd_secanalysis),\
298		      rm -f $@; $(AR) rcs $@)
299
300$(builtin-target): $(obj-y) FORCE
301	$(call if_changed,link_o_target)
302
303targets += $(builtin-target)
304endif # builtin-target
305
306#
307# Rule to create modules.order file
308#
309# Create commands to either record .ko file or cat modules.order from
310# a subdirectory
311modorder-cmds =						\
312	$(foreach m, $(modorder),			\
313		$(if $(filter %/modules.order, $m),	\
314			cat $m;, echo kernel/$m;))
315
316$(modorder-target): $(subdir-ym) FORCE
317	$(Q)(cat /dev/null; $(modorder-cmds)) > $@
318
319#
320# Rule to compile a set of .o files into one .a file
321#
322ifdef lib-target
323quiet_cmd_link_l_target = AR      $@
324cmd_link_l_target = rm -f $@; $(AR) rcs $@ $(lib-y)
325
326$(lib-target): $(lib-y) FORCE
327	$(call if_changed,link_l_target)
328
329targets += $(lib-target)
330endif
331
332#
333# Rule to link composite objects
334#
335#  Composite objects are specified in kbuild makefile as follows:
336#    <composite-object>-objs := <list of .o files>
337#  or
338#    <composite-object>-y    := <list of .o files>
339link_multi_deps =                     \
340$(filter $(addprefix $(obj)/,         \
341$($(subst $(obj)/,,$(@:.o=-objs)))    \
342$($(subst $(obj)/,,$(@:.o=-y)))), $^)
343 
344quiet_cmd_link_multi-y = LD      $@
345cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
346
347quiet_cmd_link_multi-m = LD [M]  $@
348cmd_link_multi-m = $(cmd_link_multi-y)
349
350# We would rather have a list of rules like
351# 	foo.o: $(foo-objs)
352# but that's not so easy, so we rather make all composite objects depend
353# on the set of all their parts
354$(multi-used-y) : %.o: $(multi-objs-y) FORCE
355	$(call if_changed,link_multi-y)
356
357$(multi-used-m) : %.o: $(multi-objs-m) FORCE
358	$(call if_changed,link_multi-m)
359	@{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod)
360
361targets += $(multi-used-y) $(multi-used-m)
362
363
364# Descending
365# ---------------------------------------------------------------------------
366
367PHONY += $(subdir-ym)
368$(subdir-ym):
369	$(Q)$(MAKE) $(build)=$@
370
371# Add FORCE to the prequisites of a target to force it to be always rebuilt.
372# ---------------------------------------------------------------------------
373
374PHONY += FORCE
375
376FORCE:
377
378# Read all saved command lines and dependencies for the $(targets) we
379# may be building above, using $(if_changed{,_dep}). As an
380# optimization, we don't need to read them if the target does not
381# exist, we will rebuild anyway in that case.
382
383targets := $(wildcard $(sort $(targets)))
384cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
385
386ifneq ($(cmd_files),)
387  include $(cmd_files)
388endif
389
390
391# Declare the contents of the .PHONY variable as phony.  We keep that
392# information in a variable se we can use it in if_changed and friends.
393
394.PHONY: $(PHONY)
395