mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-11-19 16:14:13 +08:00
c33df4eaaf
The file init/initramfs.c is always compiled and linked in the kernel vmlinux even when BLK_DEV_RAM and BLK_DEV_INITRD are disabled and the system isn't using any form of an initramfs or initrd. In this situation the code is only used to unpack a (static) default initial rootfilesystem. The current init/initramfs.c code. usr/initramfs_data.o compiles to a size of ~15 kbytes. Disabling BLK_DEV_RAM and BLK_DEV_INTRD shrinks the kernel code size with ~60 Kbytes. This patch avoids compiling in the code and data for initramfs support if CONFIG_BLK_DEV_INITRD is not defined. Instead of the initramfs code and data it uses a small routine in init/noinitramfs.c to setup an initial static default environment for mounting a rootfilesystem later on in the kernel initialisation process. The new code is: 164 bytes of size. The patch is separated in two parts: 1) doesn't compile initramfs code when CONFIG_BLK_DEV_INITRD is not set 2) changing all plaforms vmlinux.lds.S files to not reserve an area of PAGE_SIZE when CONFIG_BLK_DEV_INITRD is not set. [deweerdt@free.fr: warning fix] Signed-off-by: Jean-Paul Saman <jean-paul.saman@nxp.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
53 lines
1.8 KiB
Makefile
53 lines
1.8 KiB
Makefile
#
|
|
# kbuild file for usr/ - including initramfs image
|
|
#
|
|
|
|
klibcdirs:;
|
|
PHONY += klibcdirs
|
|
|
|
|
|
# Generate builtin.o based on initramfs_data.o
|
|
obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data.o
|
|
|
|
# initramfs_data.o contains the initramfs_data.cpio.gz image.
|
|
# The image is included using .incbin, a dependency which is not
|
|
# tracked automatically.
|
|
$(obj)/initramfs_data.o: $(obj)/initramfs_data.cpio.gz 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 $(CONFIG_INITRAMFS_ROOT_GID))
|
|
|
|
# .initramfs_data.cpio.gz.d is used to identify all files included
|
|
# in initramfs and to detect if any files are added/removed.
|
|
# Removed files are identified by directory timestamp being updated
|
|
# The dependency list is generated by gen_initramfs.sh -l
|
|
ifneq ($(wildcard $(obj)/.initramfs_data.cpio.gz.d),)
|
|
include $(obj)/.initramfs_data.cpio.gz.d
|
|
endif
|
|
|
|
quiet_cmd_initfs = GEN $@
|
|
cmd_initfs = $(initramfs) -o $@ $(ramfs-args) $(ramfs-input)
|
|
|
|
targets := initramfs_data.cpio.gz
|
|
# do not try to update files included in initramfs
|
|
$(deps_initramfs): ;
|
|
|
|
$(deps_initramfs): klibcdirs
|
|
# We rebuild initramfs_data.cpio.gz if:
|
|
# 1) Any included file is newer then initramfs_data.cpio.gz
|
|
# 2) There are changes in which files are included (added or deleted)
|
|
# 3) If gen_init_cpio are newer than initramfs_data.cpio.gz
|
|
# 4) arguments to gen_initramfs.sh changes
|
|
$(obj)/initramfs_data.cpio.gz: $(obj)/gen_init_cpio $(deps_initramfs) klibcdirs
|
|
$(Q)$(initramfs) -l $(ramfs-input) > $(obj)/.initramfs_data.cpio.gz.d
|
|
$(call if_changed,initfs)
|
|
|