usr/Makefile

   1 #
   2 # kbuild file for usr/ - including initramfs image
   3 #
   4
   5 klibcdirs:;
   6
   7 # Generate builtin.o based on initramfs_data.o
   8 obj-y := initramfs_data.o
   9
  10 # initramfs_data.o contains the initramfs_data.cpio.gz image.
  11 # The image is included using .incbin, a dependency which is not
  12 # tracked automatically.
  13 $(obj)/initramfs_data.o: $(obj)/initramfs_data.cpio.gz FORCE
  14
  15 #####
  16 # Generate the initramfs cpio archive
  17
  18 hostprogs-y := gen_init_cpio
  19 initramfs   := $(CONFIG_SHELL) $(srctree)/scripts/gen_initramfs_list.sh
  20 ramfs-input := $(if $(filter-out "",$(CONFIG_INITRAMFS_SOURCE)), \
  21                     $(CONFIG_INITRAMFS_SOURCE),-d)
  22 ramfs-args  := \
  23         $(if $(CONFIG_INITRAMFS_ROOT_UID), -u $(CONFIG_INITRAMFS_ROOT_UID)) \
  24         $(if $(CONFIG_INITRAMFS_ROOT_GID), -g $(CONFIG_INITRAMFS_ROOT_GID))
  25
  26 # .initramfs_data.cpio.gz.d is used to identify all files included
  27 # in initramfs and to detect if any files are added/removed.
  28 # Removed files are identified by directory timestamp being updated
  29 # The dependency list is generated by gen_initramfs.sh -l
  30 ifneq ($(wildcard $(obj)/.initramfs_data.cpio.gz.d),)
  31         include $(obj)/.initramfs_data.cpio.gz.d
  32 endif
  33
  34 quiet_cmd_initfs = GEN     $@
  35       cmd_initfs = $(initramfs) -o $@ $(ramfs-args) $(ramfs-input)
  36
  37 targets := initramfs_data.cpio.gz
  38 # do not try to update files included in initramfs
  39 $(deps_initramfs): ;
  40
  41 $(deps_initramfs): klibcdirs
  42 # We rebuild initramfs_data.cpio.gz if:
  43 # 1) Any included file is newer then initramfs_data.cpio.gz
  44 # 2) There are changes in which files are included (added or deleted)
  45 # 3) If gen_init_cpio are newer than initramfs_data.cpio.gz
  46 # 4) arguments to gen_initramfs.sh changes
  47 $(obj)/initramfs_data.cpio.gz: $(obj)/gen_init_cpio $(deps_initramfs) klibcdirs
  48         $(Q)$(initramfs) -l $(ramfs-input) > $(obj)/.initramfs_data.cpio.gz.d
  49         $(call if_changed,initfs)
  50