1 # SPDX-License-Identifier: GPL-2.0
3 # kbuild file for usr/ - including initramfs image
6 # cmd_bzip2, cmd_lzma, cmd_lzo, cmd_lz4 from scripts/Makefile.lib appends the
7 # size at the end of the compressed file, which unfortunately does not work
8 # with unpack_to_rootfs(). Make size_append no-op.
9 override size_append := :
12 compress-$(CONFIG_INITRAMFS_COMPRESSION_GZIP) := gzip
13 compress-$(CONFIG_INITRAMFS_COMPRESSION_BZIP2) := bzip2
14 compress-$(CONFIG_INITRAMFS_COMPRESSION_LZMA) := lzma
15 compress-$(CONFIG_INITRAMFS_COMPRESSION_XZ) := xzmisc
16 compress-$(CONFIG_INITRAMFS_COMPRESSION_LZO) := lzo
17 compress-$(CONFIG_INITRAMFS_COMPRESSION_LZ4) := lz4
18 compress-$(CONFIG_INITRAMFS_COMPRESSION_ZSTD) := zstd
20 obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data.o
22 $(obj)/initramfs_data.o: $(obj)/initramfs_inc_data
24 ramfs-input := $(CONFIG_INITRAMFS_SOURCE)
27 # If CONFIG_INITRAMFS_SOURCE is empty, generate a small initramfs with the
29 ifeq ($(ramfs-input),)
30 ramfs-input := $(srctree)/$(src)/default_cpio_list
33 ifeq ($(words $(ramfs-input)),1)
35 # If CONFIG_INITRAMFS_SOURCE specifies a single file, and it is suffixed with
36 # .cpio, use it directly as an initramfs.
37 ifneq ($(filter %.cpio,$(ramfs-input)),)
38 cpio-data := $(ramfs-input)
41 # If CONFIG_INITRAMFS_SOURCE specifies a single file, and it is suffixed with
42 # .cpio.*, use it directly as an initramfs, and avoid double compression.
43 ifeq ($(words $(subst .cpio.,$(space),$(ramfs-input))),2)
44 cpio-data := $(ramfs-input)
50 # For other cases, generate the initramfs cpio archive based on the contents
51 # specified by CONFIG_INITRAMFS_SOURCE.
54 cpio-data := $(obj)/initramfs_data.cpio
56 hostprogs := gen_init_cpio
58 # .initramfs_data.cpio.d is used to identify all files included
59 # in initramfs and to detect if any files are added/removed.
60 # Removed files are identified by directory timestamp being updated
61 # The dependency list is generated by gen_initramfs.sh -l
62 -include $(obj)/.initramfs_data.cpio.d
64 # do not try to update files included in initramfs
67 quiet_cmd_initfs = GEN $@
69 $(CONFIG_SHELL) $< -o $@ -l $(obj)/.initramfs_data.cpio.d \
70 $(if $(CONFIG_INITRAMFS_ROOT_UID), -u $(CONFIG_INITRAMFS_ROOT_UID)) \
71 $(if $(CONFIG_INITRAMFS_ROOT_GID), -g $(CONFIG_INITRAMFS_ROOT_GID)) \
74 # We rebuild initramfs_data.cpio if:
75 # 1) Any included file is newer than initramfs_data.cpio
76 # 2) There are changes in which files are included (added or deleted)
77 # 3) If gen_init_cpio are newer than initramfs_data.cpio
78 # 4) Arguments to gen_initramfs.sh changes
79 $(obj)/initramfs_data.cpio: $(src)/gen_initramfs.sh $(obj)/gen_init_cpio $(deps_initramfs) FORCE
80 $(call if_changed,initfs)
84 $(obj)/initramfs_inc_data: $(cpio-data) FORCE
85 $(call if_changed,$(compress-y))
87 targets += initramfs_data.cpio initramfs_inc_data
89 subdir-$(CONFIG_UAPI_HEADER_TEST) += include