linux-yocto/usr/Makefile
Nicholas Piggin 9e3596b0c6 kbuild: initramfs cleanup, set target from Kconfig
Rather than keep a list of all possible compression types in the
Makefile, set the target explicitly from Kconfig.

Reviewed-by: Francisco Blas Izquierdo Riera (klondike) <klondike@klondike.es>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-01-05 09:40:16 -08:00

2.0 KiB

kbuild file for usr/ - including initramfs image

klibcdirs:; PHONY += klibcdirs

suffix_y = $(subst $",,$(CONFIG_INITRAMFS_COMPRESSION)) datafile_y = initramfs_data.cpio$(suffix_y) AFLAGS_initramfs_data.o += -DINITRAMFS_IMAGE="usr/$(datafile_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: $(obj)/$(datafile_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 := $(datafile_y)

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

$(obj)/$(datafile_y): $(obj)/gen_init_cpio $(deps_initramfs) klibcdirs $(Q)$(initramfs) -l $(ramfs-input) > $(obj)/.initramfs_data.cpio.d $(call if_changed,initfs)