Documentation/kbuild/makefiles.rst

131 file will be used.
150 	foo.o. foo.o will be built from foo.c or foo.S.
160 	If CONFIG_FOO is neither y nor m, then the file will not be compiled
172 	This is a thin archive without a symbol table. It will be later
176 	the lists are allowed: the first instance will be linked into
177 	built-in.a and succeeding instances will be ignored.
180 	(module_init() / __initcall) will be called during boot in the
222 	In this example, the module name will be isdn.o. Kbuild will
244 	the syntax above will also work. So, if you have CONFIG_EXT2_FS=y,
245 	kbuild will build an ext2.o file for you out of the individual
259 	There is also the possibility to list objects that will
264 	lib-y will not be included in the library, since they will
266 	For consistency, objects listed in lib-m will be included in lib.a.
277 	This will create a library lib.a based on delay.o. For kbuild to
290 	Makefiles in these subdirs. The build system will automatically
304 	the corresponding obj- variable will be set, and kbuild will descend
312 	from that directory are combined into the built-in.a, which will be
316 	from that directory will be linked into vmlinux. If the Makefile in
317 	that directory specifies obj-y, those objects will be left orphan.
422 	Thus, if you change an option to $(CC) all affected files will
469 	    To support this kbuild defines $(kecho) which will echo out the
499 	In the above example, cflags-y will be assigned the option
501 	The second argument is optional, and if supplied will be used
519 	In the above example, cflags-y will be assigned the option
522 	cflags-y will be assigned no value if first option is not supported.
538 	and $(cflags-y) will be assigned the values -a32 and -m32,
552 	In the above example, -Wno-unused-but-set-variable will be added to
565 	In this example, ccflags-y will be assigned the value -O1 if the
712 	The programs will always be compiled utilising $(HOSTCC) passed
714 	To set flags that will take effect for all host programs created
737 	When linking qconf, it will be passed the extra option
743 	Kbuild will only build host-programs when they are referenced
756 	The target $(obj)/devlist.h will not be built before
776 	This will tell kbuild to build lxdialog even if not referenced in
829 	The programs will always be compiled utilising $(CC) passed
831 	To set flags that will take effect for all userspace programs created
853 	When linking bpfilter_umh, it will be passed the extra option -static.
882 	This will tell Kbuild to build binderfs_example when it visits this
904 When executing "make clean", the file "crc32table.h" will be deleted.
905 Kbuild will assume files to be in the same relative directory as the
932 When "make clean" is executed, make will descend down in arch/x86/boot,
940 Note 2: All directories listed in core-y, libs-y, drivers-y and net-y will
1006 	the flags specified in OBJCOPYFLAGS will be used.
1020 	vmlinux. The usage of $(call if_changed,xxx) will be described later.
1142 	In this example, the file target maketools will be processed
1165 	    $(init-y) objects will be located after $(head-y).
1213 	but executing "make help" will list all relevant targets.
1224 	will be built. In the top level Makefile the first goal present
1236 	When "make" is executed without arguments, bzImage will be built.
1277 	invocation. The latter will force a rebuild if any options
1280 	otherwise the command line check will fail, and the target will
1288 	significant; for instance, the below will fail (note the extra space
1320 	the targets and will:
1391 	will be displayed with "make KBUILD_VERBOSE=0".
1440 	will be invoked for post-link objects (vmlinux and modules.ko)
1503 	The generated wrapper will in both cases look like the following:
1530 	in arch/$(ARCH)/include/(uapi/)/asm, Kbuild will automatically generate
1584 	If this variable is specified, it will cause modules to be stripped
1586 	default option --strip-debug will be used.  Otherwise, the
1587 	INSTALL_MOD_STRIP value will be used as the option(s) to the strip