xref: /openbmc/linux/usr/Makefile (revision 9009b455811b0fa1f6b0adfa94db136984db5a38)
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.
9 override size_append := :
10 
11 compress-y					:= shipped
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-$(CONFIG_INITRAMFS_COMPRESSION_ZSTD)	:= zstd
19 
20 obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data.o
21 
22 $(obj)/initramfs_data.o: $(obj)/initramfs_inc_data
23 
24 ramfs-input := $(strip $(shell echo $(CONFIG_INITRAMFS_SOURCE)))
25 cpio-data :=
26 
27 # If CONFIG_INITRAMFS_SOURCE is empty, generate a small initramfs with the
28 # default contents.
29 ifeq ($(ramfs-input),)
30 ramfs-input := $(srctree)/$(src)/default_cpio_list
31 endif
32 
33 ifeq ($(words $(ramfs-input)),1)
34 
35 # If CONFIG_INITRAMFS_SOURCE specifies a single file, and it is suffixed with
36 # .cpio, use it directly as an initramfs.
37 ifneq ($(filter %.cpio,$(ramfs-input)),)
38 cpio-data := $(ramfs-input)
39 endif
40 
41 # If CONFIG_INITRAMFS_SOURCE specifies a single file, and it is suffixed with
42 # .cpio.*, use it directly as an initramfs, and avoid double compression.
43 ifeq ($(words $(subst .cpio.,$(space),$(ramfs-input))),2)
44 cpio-data := $(ramfs-input)
45 compress-y := shipped
46 endif
47 
48 endif
49 
50 # For other cases, generate the initramfs cpio archive based on the contents
51 # specified by CONFIG_INITRAMFS_SOURCE.
52 ifeq ($(cpio-data),)
53 
54 cpio-data := $(obj)/initramfs_data.cpio
55 
56 hostprogs := 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 
67 quiet_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 
82 endif
83 
84 $(obj)/initramfs_inc_data: $(cpio-data) FORCE
85 	$(call if_changed,$(compress-y))
86 
87 targets += initramfs_data.cpio initramfs_inc_data
88 
89 subdir-$(CONFIG_UAPI_HEADER_TEST) += include
90