1# SPDX-License-Identifier: GPL-2.0
2#
3# kbuild file for usr/ - including initramfs image
4#
5
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.
9override size_append := :
10
11compress-y					:= shipped
12compress-$(CONFIG_INITRAMFS_COMPRESSION_GZIP)	:= gzip
13compress-$(CONFIG_INITRAMFS_COMPRESSION_BZIP2)	:= bzip2
14compress-$(CONFIG_INITRAMFS_COMPRESSION_LZMA)	:= lzma
15compress-$(CONFIG_INITRAMFS_COMPRESSION_XZ)	:= xzmisc
16compress-$(CONFIG_INITRAMFS_COMPRESSION_LZO)	:= lzo
17compress-$(CONFIG_INITRAMFS_COMPRESSION_LZ4)	:= lz4
18compress-$(CONFIG_INITRAMFS_COMPRESSION_ZSTD)	:= zstd
19
20obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data.o
21
22$(obj)/initramfs_data.o: $(obj)/initramfs_inc_data
23
24ramfs-input := $(strip $(shell echo $(CONFIG_INITRAMFS_SOURCE)))
25cpio-data :=
26
27# If CONFIG_INITRAMFS_SOURCE is empty, generate a small initramfs with the
28# default contents.
29ifeq ($(ramfs-input),)
30ramfs-input := $(srctree)/$(src)/default_cpio_list
31endif
32
33ifeq ($(words $(ramfs-input)),1)
34
35# If CONFIG_INITRAMFS_SOURCE specifies a single file, and it is suffixed with
36# .cpio, use it directly as an initramfs.
37ifneq ($(filter %.cpio,$(ramfs-input)),)
38cpio-data := $(ramfs-input)
39endif
40
41# If CONFIG_INITRAMFS_SOURCE specifies a single file, and it is suffixed with
42# .cpio.*, use it directly as an initramfs, and avoid double compression.
43ifeq ($(words $(subst .cpio.,$(space),$(ramfs-input))),2)
44cpio-data := $(ramfs-input)
45compress-y := shipped
46endif
47
48endif
49
50# For other cases, generate the initramfs cpio archive based on the contents
51# specified by CONFIG_INITRAMFS_SOURCE.
52ifeq ($(cpio-data),)
53
54cpio-data := $(obj)/initramfs_data.cpio
55
56hostprogs := gen_init_cpio
57
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 $(obj)/.initramfs_data.cpio.d
63
64# do not try to update files included in initramfs
65$(deps_initramfs): ;
66
67quiet_cmd_initfs = GEN     $@
68      cmd_initfs = \
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)) \
72	$(ramfs-input)
73
74# We rebuild initramfs_data.cpio if:
75# 1) Any included file is newer than initramfs_data.cpio
76# 2) There are changes in which files are included (added or deleted)
77# 3) If gen_init_cpio are newer than initramfs_data.cpio
78# 4) Arguments to gen_initramfs.sh changes
79$(obj)/initramfs_data.cpio: $(src)/gen_initramfs.sh $(obj)/gen_init_cpio $(deps_initramfs) FORCE
80	$(call if_changed,initfs)
81
82endif
83
84$(obj)/initramfs_inc_data: $(cpio-data) FORCE
85	$(call if_changed,$(compress-y))
86
87targets += initramfs_data.cpio initramfs_inc_data
88
89subdir-$(CONFIG_UAPI_HEADER_TEST) += include
90