LXR linux/usr/Makefile

   1# SPDX-License-Identifier: GPL-2.0
   2#
   3# kbuild file for usr/ - including initramfs image
   4#
   5
   6compress-y                                      := copy
   7compress-$(CONFIG_INITRAMFS_COMPRESSION_GZIP)   := gzip
   8compress-$(CONFIG_INITRAMFS_COMPRESSION_BZIP2)  := bzip2
   9compress-$(CONFIG_INITRAMFS_COMPRESSION_LZMA)   := lzma
  10compress-$(CONFIG_INITRAMFS_COMPRESSION_XZ)     := xzmisc
  11compress-$(CONFIG_INITRAMFS_COMPRESSION_LZO)    := lzo
  12compress-$(CONFIG_INITRAMFS_COMPRESSION_LZ4)    := lz4
  13compress-$(CONFIG_INITRAMFS_COMPRESSION_ZSTD)   := zstd
  14
  15obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data.o
  16
  17$(obj)/initramfs_data.o: $(obj)/initramfs_inc_data
  18
  19ramfs-input := $(CONFIG_INITRAMFS_SOURCE)
  20cpio-data :=
  21
  22# If CONFIG_INITRAMFS_SOURCE is empty, generate a small initramfs with the
  23# default contents.
  24ifeq ($(ramfs-input),)
  25ramfs-input := $(src)/default_cpio_list
  26endif
  27
  28ifeq ($(words $(ramfs-input)),1)
  29
  30# If CONFIG_INITRAMFS_SOURCE specifies a single file, and it is suffixed with
  31# .cpio, use it directly as an initramfs.
  32ifneq ($(filter %.cpio,$(ramfs-input)),)
  33cpio-data := $(ramfs-input)
  34endif
  35
  36# If CONFIG_INITRAMFS_SOURCE specifies a single file, and it is suffixed with
  37# .cpio.*, use it directly as an initramfs, and avoid double compression.
  38ifeq ($(words $(subst .cpio.,$(space),$(ramfs-input))),2)
  39cpio-data := $(ramfs-input)
  40compress-y := copy
  41endif
  42
  43endif
  44
  45# For other cases, generate the initramfs cpio archive based on the contents
  46# specified by CONFIG_INITRAMFS_SOURCE.
  47ifeq ($(cpio-data),)
  48
  49cpio-data := $(obj)/initramfs_data.cpio
  50
  51hostprogs := gen_init_cpio
  52
  53# .initramfs_data.cpio.d is used to identify all files included
  54# in initramfs and to detect if any files are added/removed.
  55# Removed files are identified by directory timestamp being updated
  56# The dependency list is generated by gen_initramfs.sh -l
  57-include $(obj)/.initramfs_data.cpio.d
  58
  59# do not try to update files included in initramfs
  60$(deps_initramfs): ;
  61
  62quiet_cmd_initfs = GEN     $@
  63      cmd_initfs = \
  64        $(CONFIG_SHELL) $< -o $@ -l $(obj)/.initramfs_data.cpio.d \
  65        $(addprefix -u , $(CONFIG_INITRAMFS_ROOT_UID)) \
  66        $(addprefix -g , $(CONFIG_INITRAMFS_ROOT_GID)) \
  67        $(if $(KBUILD_BUILD_TIMESTAMP), -d "$(KBUILD_BUILD_TIMESTAMP)") \
  68        $(ramfs-input)
  69
  70# We rebuild initramfs_data.cpio if:
  71# 1) Any included file is newer than initramfs_data.cpio
  72# 2) There are changes in which files are included (added or deleted)
  73# 3) If gen_init_cpio are newer than initramfs_data.cpio
  74# 4) Arguments to gen_initramfs.sh changes
  75$(obj)/initramfs_data.cpio: $(src)/gen_initramfs.sh $(obj)/gen_init_cpio $(deps_initramfs) FORCE
  76        $(call if_changed,initfs)
  77
  78endif
  79
  80$(obj)/initramfs_inc_data: $(cpio-data) FORCE
  81        $(call if_changed,$(compress-y))
  82
  83targets += initramfs_data.cpio initramfs_inc_data
  84
  85subdir-$(CONFIG_UAPI_HEADER_TEST) += include
  86