1 # SPDX-License-Identifier: GPL-2.0
3 # kbuild file for usr/ - including initramfs image
9 suffix_y = $(subst $\",,$(CONFIG_INITRAMFS_COMPRESSION))
10 datafile_y = initramfs_data.cpio$(suffix_y)
11 datafile_d_y = .$(datafile_y).d
12 AFLAGS_initramfs_data.o += -DINITRAMFS_IMAGE="usr/$(datafile_y)"
15 # Generate builtin.o based on initramfs_data.o
16 obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data.o
18 # initramfs_data.o contains the compressed initramfs_data.cpio image.
19 # The image is included using .incbin, a dependency which is not
20 # tracked automatically.
21 $(obj)/initramfs_data.o: $(obj)/$(datafile_y) FORCE
24 # Generate the initramfs cpio archive
26 hostprogs-y := gen_init_cpio
27 initramfs := $(CONFIG_SHELL) $(srctree)/$(src)/gen_initramfs_list.sh
28 ramfs-input := $(if $(filter-out "",$(CONFIG_INITRAMFS_SOURCE)), \
29 $(shell echo $(CONFIG_INITRAMFS_SOURCE)),-d)
31 $(if $(CONFIG_INITRAMFS_ROOT_UID), -u $(CONFIG_INITRAMFS_ROOT_UID)) \
32 $(if $(CONFIG_INITRAMFS_ROOT_GID), -g $(CONFIG_INITRAMFS_ROOT_GID))
34 # $(datafile_d_y) is used to identify all files included
35 # in initramfs and to detect if any files are added/removed.
36 # Removed files are identified by directory timestamp being updated
37 # The dependency list is generated by gen_initramfs.sh -l
38 ifneq ($(wildcard $(obj)/$(datafile_d_y)),)
39 include $(obj)/$(datafile_d_y)
42 quiet_cmd_initfs = GEN $@
43 cmd_initfs = $(initramfs) -o $@ $(ramfs-args) $(ramfs-input)
45 targets := $(datafile_y)
47 # do not try to update files included in initramfs
50 $(deps_initramfs): klibcdirs
51 # We rebuild initramfs_data.cpio if:
52 # 1) Any included file is newer than initramfs_data.cpio
53 # 2) There are changes in which files are included (added or deleted)
54 # 3) If gen_init_cpio are newer than initramfs_data.cpio
55 # 4) Arguments to gen_initramfs.sh changes
56 $(obj)/$(datafile_y): $(obj)/gen_init_cpio $(deps_initramfs) klibcdirs
57 $(Q)$(initramfs) -l $(ramfs-input) > $(obj)/$(datafile_d_y)
58 $(call if_changed,initfs)