1 # SPDX-License-Identifier: GPL-2.0
3 # kbuild file for usr/ - including initramfs image
7 compress-$(CONFIG_INITRAMFS_COMPRESSION_GZIP) := gzip
8 compress-$(CONFIG_INITRAMFS_COMPRESSION_BZIP2) := bzip2
9 compress-$(CONFIG_INITRAMFS_COMPRESSION_LZMA) := lzma
10 compress-$(CONFIG_INITRAMFS_COMPRESSION_XZ) := xzmisc
11 compress-$(CONFIG_INITRAMFS_COMPRESSION_LZO) := lzo
12 compress-$(CONFIG_INITRAMFS_COMPRESSION_LZ4) := lz4
13 compress-$(CONFIG_INITRAMFS_COMPRESSION_ZSTD) := zstd
15 obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data.o
17 $(obj)/initramfs_data.o: $(obj)/initramfs_inc_data
19 ramfs-input := $(CONFIG_INITRAMFS_SOURCE)
22 # If CONFIG_INITRAMFS_SOURCE is empty, generate a small initramfs with the
24 ifeq ($(ramfs-input),)
25 ramfs-input := $(srctree)/$(src)/default_cpio_list
28 ifeq ($(words $(ramfs-input)),1)
30 # If CONFIG_INITRAMFS_SOURCE specifies a single file, and it is suffixed with
31 # .cpio, use it directly as an initramfs.
32 ifneq ($(filter %.cpio,$(ramfs-input)),)
33 cpio-data := $(ramfs-input)
36 # If CONFIG_INITRAMFS_SOURCE specifies a single file, and it is suffixed with
37 # .cpio.*, use it directly as an initramfs, and avoid double compression.
38 ifeq ($(words $(subst .cpio.,$(space),$(ramfs-input))),2)
39 cpio-data := $(ramfs-input)
45 # For other cases, generate the initramfs cpio archive based on the contents
46 # specified by CONFIG_INITRAMFS_SOURCE.
49 cpio-data := $(obj)/initramfs_data.cpio
51 hostprogs := gen_init_cpio
53 # .initramfs_data.cpio.d is used to identify all files included
54 # in initramfs and to detect if any files are added/removed.
55 # Removed files are identified by directory timestamp being updated
56 # The dependency list is generated by gen_initramfs.sh -l
57 -include $(obj)/.initramfs_data.cpio.d
59 # do not try to update files included in initramfs
62 quiet_cmd_initfs = GEN $@
64 $(CONFIG_SHELL) $< -o $@ -l $(obj)/.initramfs_data.cpio.d \
65 $(if $(CONFIG_INITRAMFS_ROOT_UID), -u $(CONFIG_INITRAMFS_ROOT_UID)) \
66 $(if $(CONFIG_INITRAMFS_ROOT_GID), -g $(CONFIG_INITRAMFS_ROOT_GID)) \
69 # We rebuild initramfs_data.cpio if:
70 # 1) Any included file is newer than initramfs_data.cpio
71 # 2) There are changes in which files are included (added or deleted)
72 # 3) If gen_init_cpio are newer than initramfs_data.cpio
73 # 4) Arguments to gen_initramfs.sh changes
74 $(obj)/initramfs_data.cpio: $(src)/gen_initramfs.sh $(obj)/gen_init_cpio $(deps_initramfs) FORCE
75 $(call if_changed,initfs)
79 $(obj)/initramfs_inc_data: $(cpio-data) FORCE
80 $(call if_changed,$(compress-y))
82 targets += initramfs_data.cpio initramfs_inc_data
84 subdir-$(CONFIG_UAPI_HEADER_TEST) += include