LXR linux/usr/Makefile

   1# SPDX-License-Identifier: GPL-2.0
   2#
   3# kbuild file for usr/ - including initramfs image
   4#
   5
   6# cmd_bzip2, cmd_lzma, cmd_lzo, cmd_lz4 from scripts/Makefile.lib appends the
   7# size at the end of the compressed file, which unfortunately does not work
   8# with unpack_to_rootfs(). Make size_append no-op.
   9override size_append := :
  10
  11compress-y                                      := shipped
  12compress-$(CONFIG_INITRAMFS_COMPRESSION_GZIP)   := gzip
  13compress-$(CONFIG_INITRAMFS_COMPRESSION_BZIP2)  := bzip2
  14compress-$(CONFIG_INITRAMFS_COMPRESSION_LZMA)   := lzma
  15compress-$(CONFIG_INITRAMFS_COMPRESSION_XZ)     := xzmisc
  16compress-$(CONFIG_INITRAMFS_COMPRESSION_LZO)    := lzo
  17compress-$(CONFIG_INITRAMFS_COMPRESSION_LZ4)    := lz4
  18compress-$(CONFIG_INITRAMFS_COMPRESSION_ZSTD)   := zstd
  19
  20obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data.o
  21
  22$(obj)/initramfs_data.o: $(obj)/initramfs_inc_data
  23
  24ramfs-input := $(strip $(shell echo $(CONFIG_INITRAMFS_SOURCE)))
  25cpio-data :=
  26
  27# If CONFIG_INITRAMFS_SOURCE is empty, generate a small initramfs with the
  28# default contents.
  29ifeq ($(ramfs-input),)
  30ramfs-input := $(srctree)/$(src)/default_cpio_list
  31endif
  32
  33ifeq ($(words $(ramfs-input)),1)
  34
  35# If CONFIG_INITRAMFS_SOURCE specifies a single file, and it is suffixed with
  36# .cpio, use it directly as an initramfs.
  37ifneq ($(filter %.cpio,$(ramfs-input)),)
  38cpio-data := $(ramfs-input)
  39endif
  40
  41# If CONFIG_INITRAMFS_SOURCE specifies a single file, and it is suffixed with
  42# .cpio.*, use it directly as an initramfs, and avoid double compression.
  43ifeq ($(words $(subst .cpio.,$(space),$(ramfs-input))),2)
  44cpio-data := $(ramfs-input)
  45compress-y := shipped
  46endif
  47
  48endif
  49
  50# For other cases, generate the initramfs cpio archive based on the contents
  51# specified by CONFIG_INITRAMFS_SOURCE.
  52ifeq ($(cpio-data),)
  53
  54cpio-data := $(obj)/initramfs_data.cpio
  55
  56hostprogs := gen_init_cpio
  57
  58# .initramfs_data.cpio.d is used to identify all files included
  59# in initramfs and to detect if any files are added/removed.
  60# Removed files are identified by directory timestamp being updated
  61# The dependency list is generated by gen_initramfs.sh -l
  62-include $(obj)/.initramfs_data.cpio.d
  63
  64# do not try to update files included in initramfs
  65$(deps_initramfs): ;
  66
  67quiet_cmd_initfs = GEN     $@
  68      cmd_initfs = \
  69        $(CONFIG_SHELL) $< -o $@ -l $(obj)/.initramfs_data.cpio.d \
  70        $(if $(CONFIG_INITRAMFS_ROOT_UID), -u $(CONFIG_INITRAMFS_ROOT_UID)) \
  71        $(if $(CONFIG_INITRAMFS_ROOT_GID), -g $(CONFIG_INITRAMFS_ROOT_GID)) \
  72        $(ramfs-input)
  73
  74# We rebuild initramfs_data.cpio if:
  75# 1) Any included file is newer than initramfs_data.cpio
  76# 2) There are changes in which files are included (added or deleted)
  77# 3) If gen_init_cpio are newer than initramfs_data.cpio
  78# 4) Arguments to gen_initramfs.sh changes
  79$(obj)/initramfs_data.cpio: $(src)/gen_initramfs.sh $(obj)/gen_init_cpio $(deps_initramfs) FORCE
  80        $(call if_changed,initfs)
  81
  82endif
  83
  84$(obj)/initramfs_inc_data: $(cpio-data) FORCE
  85        $(call if_changed,$(compress-y))
  86
  87targets += initramfs_data.cpio initramfs_inc_data
  88
  89subdir-$(CONFIG_UAPI_HEADER_TEST) += include
  90