linux/usr/Makefile
Masahiro Yamada 65e00e04e5 initramfs: refactor the initramfs build rules
Currently, usr/gen_initramfs.sh takes care of all the use-cases:

 [1] generates a cpio file unless CONFIG_INITRAMFS_SOURCE points to
     a single cpio archive

 [2] If CONFIG_INITRAMFS_SOURCE is the path to a cpio archive,
     use it as-is.

 [3] Compress the cpio file according to CONFIG_INITRAMFS_COMPRESSION_*
     unless it is passed a compressed archive.

To simplify the script, move [2] and [3] to usr/Makefile.

If CONFIG_INITRAMFS_SOURCE is the path to a cpio archive, there is
no need to run this shell script.

For the cpio archive compression, you can re-use the rules from
scripts/Makefile.lib .

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-16 00:26:21 +09:00

89 lines
2.9 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
#
# kbuild file for usr/ - including initramfs image
#
# cmd_bzip2, cmd_lzma, cmd_lzo, cmd_lz4 from scripts/Makefile.lib appends the
# size at the end of the compressed file, which unfortunately does not work
# with unpack_to_rootfs(). Make size_append no-op.
override size_append := :
compress-$(CONFIG_INITRAMFS_COMPRESSION_NONE) := shipped
compress-$(CONFIG_INITRAMFS_COMPRESSION_GZIP) := gzip
compress-$(CONFIG_INITRAMFS_COMPRESSION_BZIP2) := bzip2
compress-$(CONFIG_INITRAMFS_COMPRESSION_LZMA) := lzma
compress-$(CONFIG_INITRAMFS_COMPRESSION_XZ) := xzmisc
compress-$(CONFIG_INITRAMFS_COMPRESSION_LZO) := lzo
compress-$(CONFIG_INITRAMFS_COMPRESSION_LZ4) := lz4
obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data.o
$(obj)/initramfs_data.o: $(obj)/initramfs_inc_data
ramfs-input := $(strip $(shell echo $(CONFIG_INITRAMFS_SOURCE)))
cpio-data :=
# If CONFIG_INITRAMFS_SOURCE is empty, generate a small initramfs with the
# default contents.
ifeq ($(ramfs-input),)
ramfs-input := $(srctree)/$(src)/default_cpio_list
endif
ifeq ($(words $(ramfs-input)),1)
# If CONFIG_INITRAMFS_SOURCE specifies a single file, and it is suffixed with
# .cpio, use it directly as an initramfs.
ifneq ($(filter %.cpio,$(ramfs-input)),)
cpio-data := $(ramfs-input)
endif
# If CONFIG_INITRAMFS_SOURCE specifies a single file, and it is suffixed with
# .cpio.*, use it directly as an initramfs, and avoid double compression.
ifeq ($(words $(subst .cpio.,$(space),$(ramfs-input))),2)
cpio-data := $(ramfs-input)
compress-y := shipped
endif
endif
# For other cases, generate the initramfs cpio archive based on the contents
# specified by CONFIG_INITRAMFS_SOURCE.
ifeq ($(cpio-data),)
cpio-data := $(obj)/initramfs_data.cpio
hostprogs-y := gen_init_cpio
# .initramfs_data.cpio.d is used to identify all files included
# in initramfs and to detect if any files are added/removed.
# Removed files are identified by directory timestamp being updated
# The dependency list is generated by gen_initramfs.sh -l
-include $(obj)/.initramfs_data.cpio.d
# do not try to update files included in initramfs
$(deps_initramfs): ;
quiet_cmd_initfs = GEN $@
cmd_initfs = \
$(CONFIG_SHELL) $< -o $@ -l $(obj)/.initramfs_data.cpio.d \
$(if $(CONFIG_INITRAMFS_ROOT_UID), -u $(CONFIG_INITRAMFS_ROOT_UID)) \
$(if $(CONFIG_INITRAMFS_ROOT_GID), -g $(CONFIG_INITRAMFS_ROOT_GID)) \
$(ramfs-input)
# We rebuild initramfs_data.cpio if:
# 1) Any included file is newer than initramfs_data.cpio
# 2) There are changes in which files are included (added or deleted)
# 3) If gen_init_cpio are newer than initramfs_data.cpio
# 4) Arguments to gen_initramfs.sh changes
$(obj)/initramfs_data.cpio: $(src)/gen_initramfs.sh $(obj)/gen_init_cpio $(deps_initramfs) FORCE
$(call if_changed,initfs)
endif
$(obj)/initramfs_inc_data: $(cpio-data) FORCE
$(call if_changed,$(compress-y))
targets += initramfs_data.cpio initramfs_inc_data
subdir-$(CONFIG_UAPI_HEADER_TEST) += include