xref: /linux/init/Makefile (revision a1ff5a7d78a036d6c2178ee5acd6ba4946243800)
1# SPDX-License-Identifier: GPL-2.0
2#
3# Makefile for the linux kernel.
4#
5
6ccflags-y := -fno-function-sections -fno-data-sections
7
8obj-y                          := main.o version.o mounts.o
9ifneq ($(CONFIG_BLK_DEV_INITRD),y)
10obj-y                          += noinitramfs.o
11else
12obj-$(CONFIG_BLK_DEV_INITRD)   += initramfs.o
13endif
14obj-$(CONFIG_GENERIC_CALIBRATE_DELAY) += calibrate.o
15
16obj-y                          += init_task.o
17
18mounts-y			:= do_mounts.o
19mounts-$(CONFIG_BLK_DEV_RAM)	+= do_mounts_rd.o
20mounts-$(CONFIG_BLK_DEV_INITRD)	+= do_mounts_initrd.o
21
22#
23# UTS_VERSION
24#
25
26smp-flag-$(CONFIG_SMP)			:= SMP
27preempt-flag-$(CONFIG_PREEMPT_BUILD)	:= PREEMPT
28preempt-flag-$(CONFIG_PREEMPT_DYNAMIC)	:= PREEMPT_DYNAMIC
29preempt-flag-$(CONFIG_PREEMPT_RT)	:= PREEMPT_RT
30
31build-version = $(or $(KBUILD_BUILD_VERSION), $(build-version-auto))
32build-timestamp = $(or $(KBUILD_BUILD_TIMESTAMP), $(build-timestamp-auto))
33
34# Maximum length of UTS_VERSION is 64 chars
35filechk_uts_version = \
36	utsver=$$(echo '$(pound)'"$(build-version)" $(smp-flag-y) $(preempt-flag-y) "$(build-timestamp)" | cut -b -64); \
37	echo '$(pound)'define UTS_VERSION \""$${utsver}"\"
38
39#
40# Build version.c with temporary UTS_VERSION
41#
42
43$(obj)/utsversion-tmp.h: FORCE
44	$(call filechk,uts_version)
45
46clean-files += utsversion-tmp.h
47
48$(obj)/version.o: $(obj)/utsversion-tmp.h
49CFLAGS_version.o := -include $(obj)/utsversion-tmp.h
50
51#
52# Build version-timestamp.c with final UTS_VERSION
53#
54
55include/generated/utsversion.h: build-version-auto = $(shell $(srctree)/scripts/build-version)
56include/generated/utsversion.h: build-timestamp-auto = $(shell LC_ALL=C date)
57include/generated/utsversion.h: FORCE
58	$(call filechk,uts_version)
59
60$(obj)/version-timestamp.o: include/generated/utsversion.h
61CFLAGS_version-timestamp.o := -include include/generated/utsversion.h
62