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linux/usr/Makefile
P J P 9ba4bcb645 initramfs: read CONFIG_RD_ variables for initramfs compression
When expert configuration option(CONFIG_EXPERT) is enabled, menuconfig
offers a choice of compression algorithm to compress initial ramfs image;
This choice is stored into CONFIG_RD_* variables.  But usr/Makefile uses
earlier INITRAMFS_COMPRESSION_* macros to build initial ramfs file.  Since
none of them is defined, resulting 'initramfs_data.cpio' file remains
un-compressed.

This patch updates the Makefile to use CONFIG_RD_* variables and adds
support for LZ4 compression algorithm.  Also updates the
'gen_initramfs_list.sh' script to check whether a selected compression
command is accessible or not.  And fall-back to default gzip(1)
compression when it is not.

Signed-off-by: P J P <prasad@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:26 +09:00

75 lines
2.3 KiB
Makefile

#
# kbuild file for usr/ - including initramfs image
#
klibcdirs:;
PHONY += klibcdirs
# Bzip2
suffix_$(CONFIG_RD_BZIP2) = .bz2
# Lzma
suffix_$(CONFIG_RD_LZMA) = .lzma
# XZ
suffix_$(CONFIG_RD_XZ) = .xz
# Lzo
suffix_$(CONFIG_RD_LZO) = .lzo
# Lz4
suffix_$(CONFIG_RD_LZ4) = .lz4
# Gzip
suffix_$(CONFIG_RD_GZIP) = .gz
AFLAGS_initramfs_data.o += -DINITRAMFS_IMAGE="usr/initramfs_data.cpio$(suffix_y)"
# Generate builtin.o based on initramfs_data.o
obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data.o
# initramfs_data.o contains the compressed initramfs_data.cpio image.
# The image is included using .incbin, a dependency which is not
# tracked automatically.
$(obj)/initramfs_data.o: $(obj)/initramfs_data.cpio$(suffix_y) FORCE
#####
# Generate the initramfs cpio archive
hostprogs-y := gen_init_cpio
initramfs := $(CONFIG_SHELL) $(srctree)/scripts/gen_initramfs_list.sh
ramfs-input := $(if $(filter-out "",$(CONFIG_INITRAMFS_SOURCE)), \
$(shell echo $(CONFIG_INITRAMFS_SOURCE)),-d)
ramfs-args := \
$(if $(CONFIG_INITRAMFS_ROOT_UID), -u $(CONFIG_INITRAMFS_ROOT_UID)) \
$(if $(CONFIG_INITRAMFS_ROOT_GID), -g $(CONFIG_INITRAMFS_ROOT_GID))
# .initramfs_data.cpio.d is used to identify all files included
# in initramfs and to detect if any files are added/removed.
# Removed files are identified by directory timestamp being updated
# The dependency list is generated by gen_initramfs.sh -l
ifneq ($(wildcard $(obj)/.initramfs_data.cpio.d),)
include $(obj)/.initramfs_data.cpio.d
endif
quiet_cmd_initfs = GEN $@
cmd_initfs = $(initramfs) -o $@ $(ramfs-args) $(ramfs-input)
targets := initramfs_data.cpio.gz initramfs_data.cpio.bz2 \
initramfs_data.cpio.lzma initramfs_data.cpio.xz \
initramfs_data.cpio.lzo initramfs_data.cpio.lz4 \
initramfs_data.cpio
# do not try to update files included in initramfs
$(deps_initramfs): ;
$(deps_initramfs): klibcdirs
# We rebuild initramfs_data.cpio if:
# 1) Any included file is newer then 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
$(obj)/initramfs_data.cpio$(suffix_y): $(obj)/gen_init_cpio $(deps_initramfs) klibcdirs
$(Q)$(initramfs) -l $(ramfs-input) > $(obj)/.initramfs_data.cpio.d
$(call if_changed,initfs)