projects/linux·blob master · refs

85 lines · 2.7 KiB

1# SPDX-License-Identifier: GPL-2.0
2#
3# kbuild file for usr/ - including initramfs image
4#
5
6compress-y := copy
7compress-$(CONFIG_INITRAMFS_COMPRESSION_GZIP) := gzip
8compress-$(CONFIG_INITRAMFS_COMPRESSION_BZIP2) := bzip2
9compress-$(CONFIG_INITRAMFS_COMPRESSION_LZMA) := lzma
10compress-$(CONFIG_INITRAMFS_COMPRESSION_XZ) := xzmisc
11compress-$(CONFIG_INITRAMFS_COMPRESSION_LZO) := lzo
12compress-$(CONFIG_INITRAMFS_COMPRESSION_LZ4) := lz4
13compress-$(CONFIG_INITRAMFS_COMPRESSION_ZSTD) := zstd
14
15obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data.o
16
17$(obj)/initramfs_data.o: $(obj)/initramfs_inc_data
18
19hostprogs := gen_init_cpio
20
21ramfs-input := $(CONFIG_INITRAMFS_SOURCE)
22cpio-data :=
23
24# If CONFIG_INITRAMFS_SOURCE is empty, generate a small initramfs with the
25# default contents.
26ifeq ($(ramfs-input),)
27ramfs-input := $(src)/default_cpio_list
28endif
29
30ifeq ($(words $(ramfs-input)),1)
31
32# If CONFIG_INITRAMFS_SOURCE specifies a single file, and it is suffixed with
33# .cpio, use it directly as an initramfs.
34ifneq ($(filter %.cpio,$(ramfs-input)),)
35cpio-data := $(ramfs-input)
36endif
37
38# If CONFIG_INITRAMFS_SOURCE specifies a single file, and it is suffixed with
39# .cpio.*, use it directly as an initramfs, and avoid double compression.
40ifeq ($(words $(subst .cpio.,$(space),$(ramfs-input))),2)
41cpio-data := $(ramfs-input)
42compress-y := copy
43endif
44
45endif
46
47# For other cases, generate the initramfs cpio archive based on the contents
48# specified by CONFIG_INITRAMFS_SOURCE.
49ifeq ($(cpio-data),)
50
51cpio-data := $(obj)/initramfs_data.cpio
52
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 $(obj)/.initramfs_data.cpio.d
58
59# do not try to update files included in initramfs
60$(deps_initramfs): ;
61
62quiet_cmd_initfs = GEN $@
63 cmd_initfs = \
64 $(CONFIG_SHELL) $< -o $@ -l $(obj)/.initramfs_data.cpio.d \
65 $(addprefix -u , $(CONFIG_INITRAMFS_ROOT_UID)) \
66 $(addprefix -g , $(CONFIG_INITRAMFS_ROOT_GID)) \
67 $(if $(KBUILD_BUILD_TIMESTAMP), -d "$(KBUILD_BUILD_TIMESTAMP)") \
68 $(ramfs-input)
69
70# We rebuild initramfs_data.cpio if:
71# 1) Any included file is newer than initramfs_data.cpio
72# 2) There are changes in which files are included (added or deleted)
73# 3) If gen_init_cpio are newer than initramfs_data.cpio
74# 4) Arguments to gen_initramfs.sh changes
75$(obj)/initramfs_data.cpio: $(src)/gen_initramfs.sh $(obj)/gen_init_cpio $(deps_initramfs) FORCE
76 $(call if_changed,initfs)
77
78endif
79
80$(obj)/initramfs_inc_data: $(cpio-data) FORCE
81 $(call if_changed,$(compress-y))
82
83targets += initramfs_data.cpio initramfs_inc_data
84
85subdir-$(CONFIG_UAPI_HEADER_TEST) += include