1

initramfs: refactor the initramfs build rules

Currently, usr/gen_initramfs.sh takes care of all the use-cases:

 [1] generates a cpio file unless CONFIG_INITRAMFS_SOURCE points to
     a single cpio archive

 [2] If CONFIG_INITRAMFS_SOURCE is the path to a cpio archive,
     use it as-is.

 [3] Compress the cpio file according to CONFIG_INITRAMFS_COMPRESSION_*
     unless it is passed a compressed archive.

To simplify the script, move [2] and [3] to usr/Makefile.

If CONFIG_INITRAMFS_SOURCE is the path to a cpio archive, there is
no need to run this shell script.

For the cpio archive compression, you can re-use the rules from
scripts/Makefile.lib .

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This commit is contained in:
Masahiro Yamada 2020-01-05 00:02:37 +09:00
parent 469e87e89f
commit 65e00e04e5
5 changed files with 78 additions and 111 deletions

8
usr/.gitignore vendored
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@ -1,9 +1,3 @@
#
# Generated files
#
gen_init_cpio
initramfs_data.cpio
initramfs_data.cpio.gz
initramfs_data.cpio.bz2
initramfs_data.cpio.lzma
initramfs_list
/initramfs_inc_data

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@ -207,13 +207,3 @@ config INITRAMFS_COMPRESSION_LZ4
by default which could cause a build failure.
endchoice
config INITRAMFS_COMPRESSION
string
default "" if INITRAMFS_COMPRESSION_NONE
default ".gz" if INITRAMFS_COMPRESSION_GZIP
default ".bz2" if INITRAMFS_COMPRESSION_BZIP2
default ".lzma" if INITRAMFS_COMPRESSION_LZMA
default ".xz" if INITRAMFS_COMPRESSION_XZ
default ".lzo" if INITRAMFS_COMPRESSION_LZO
default ".lz4" if INITRAMFS_COMPRESSION_LZ4

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@ -3,55 +3,86 @@
# kbuild file for usr/ - including initramfs image
#
suffix_y = $(subst $\",,$(CONFIG_INITRAMFS_COMPRESSION))
datafile_y = initramfs_data.cpio$(suffix_y)
datafile_d_y = .$(datafile_y).d
AFLAGS_initramfs_data.o += -DINITRAMFS_IMAGE="usr/$(datafile_y)"
# cmd_bzip2, cmd_lzma, cmd_lzo, cmd_lz4 from scripts/Makefile.lib appends the
# size at the end of the compressed file, which unfortunately does not work
# with unpack_to_rootfs(). Make size_append no-op.
override size_append := :
# clean rules do not have CONFIG_INITRAMFS_COMPRESSION. So clean up after all
# possible compression formats.
clean-files += initramfs_data.cpio*
compress-$(CONFIG_INITRAMFS_COMPRESSION_NONE) := shipped
compress-$(CONFIG_INITRAMFS_COMPRESSION_GZIP) := gzip
compress-$(CONFIG_INITRAMFS_COMPRESSION_BZIP2) := bzip2
compress-$(CONFIG_INITRAMFS_COMPRESSION_LZMA) := lzma
compress-$(CONFIG_INITRAMFS_COMPRESSION_XZ) := xzmisc
compress-$(CONFIG_INITRAMFS_COMPRESSION_LZO) := lzo
compress-$(CONFIG_INITRAMFS_COMPRESSION_LZ4) := lz4
# 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
$(obj)/initramfs_data.o: $(obj)/initramfs_inc_data
#####
# Generate the initramfs cpio archive
ramfs-input := $(strip $(shell echo $(CONFIG_INITRAMFS_SOURCE)))
cpio-data :=
# If CONFIG_INITRAMFS_SOURCE is empty, generate a small initramfs with the
# default contents.
ifeq ($(ramfs-input),)
ramfs-input := $(srctree)/$(src)/default_cpio_list
endif
ifeq ($(words $(ramfs-input)),1)
# If CONFIG_INITRAMFS_SOURCE specifies a single file, and it is suffixed with
# .cpio, use it directly as an initramfs.
ifneq ($(filter %.cpio,$(ramfs-input)),)
cpio-data := $(ramfs-input)
endif
# If CONFIG_INITRAMFS_SOURCE specifies a single file, and it is suffixed with
# .cpio.*, use it directly as an initramfs, and avoid double compression.
ifeq ($(words $(subst .cpio.,$(space),$(ramfs-input))),2)
cpio-data := $(ramfs-input)
compress-y := shipped
endif
endif
# For other cases, generate the initramfs cpio archive based on the contents
# specified by CONFIG_INITRAMFS_SOURCE.
ifeq ($(cpio-data),)
cpio-data := $(obj)/initramfs_data.cpio
hostprogs-y := gen_init_cpio
ramfs-input := $(if $(filter-out "",$(CONFIG_INITRAMFS_SOURCE)), \
$(shell echo $(CONFIG_INITRAMFS_SOURCE)),$(srctree)/$(src)/default_cpio_list)
ramfs-args := \
$(if $(CONFIG_INITRAMFS_ROOT_UID), -u $(CONFIG_INITRAMFS_ROOT_UID)) \
$(if $(CONFIG_INITRAMFS_ROOT_GID), -g $(CONFIG_INITRAMFS_ROOT_GID))
# $(datafile_d_y) is used to identify all files included
# .initramfs_data.cpio.d is used to identify all files included
# in initramfs and to detect if any files are added/removed.
# Removed files are identified by directory timestamp being updated
# The dependency list is generated by gen_initramfs.sh -l
ifneq ($(wildcard $(obj)/$(datafile_d_y)),)
include $(obj)/$(datafile_d_y)
endif
quiet_cmd_initfs = GEN $@
cmd_initfs = $(CONFIG_SHELL) $< -o $@ -l $(obj)/$(datafile_d_y) $(ramfs-args) $(ramfs-input)
targets := $(datafile_y)
-include $(obj)/.initramfs_data.cpio.d
# do not try to update files included in initramfs
$(deps_initramfs): ;
quiet_cmd_initfs = GEN $@
cmd_initfs = \
$(CONFIG_SHELL) $< -o $@ -l $(obj)/.initramfs_data.cpio.d \
$(if $(CONFIG_INITRAMFS_ROOT_UID), -u $(CONFIG_INITRAMFS_ROOT_UID)) \
$(if $(CONFIG_INITRAMFS_ROOT_GID), -g $(CONFIG_INITRAMFS_ROOT_GID)) \
$(ramfs-input)
# We rebuild initramfs_data.cpio if:
# 1) Any included file is newer than 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): $(src)/gen_initramfs.sh $(obj)/gen_init_cpio $(deps_initramfs) FORCE
$(obj)/initramfs_data.cpio: $(src)/gen_initramfs.sh $(obj)/gen_init_cpio $(deps_initramfs) FORCE
$(call if_changed,initfs)
endif
$(obj)/initramfs_inc_data: $(cpio-data) FORCE
$(call if_changed,$(compress-y))
targets += initramfs_data.cpio initramfs_inc_data
subdir-$(CONFIG_UAPI_HEADER_TEST) += include

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@ -5,7 +5,7 @@
# Released under the terms of the GNU GPL
#
# Generate a cpio packed initramfs. It uses gen_init_cpio to generate
# the cpio archive, and then compresses it.
# the cpio archive.
# This script assumes that gen_init_cpio is located in usr/ directory
# error out on errors
@ -15,8 +15,7 @@ usage() {
cat << EOF
Usage:
$0 [-o <file>] [-l <dep_list>] [-u <uid>] [-g <gid>] {-d | <cpio_source>} ...
-o <file> Create compressed initramfs file named <file> using
gen_init_cpio and compressor depending on the extension
-o <file> Create initramfs file named <file> by using gen_init_cpio
-l <dep_list> Create dependency list named <dep_list>
-u <uid> User ID to map to user ID 0 (root).
<uid> is only meaningful if <cpio_source> is a
@ -162,20 +161,12 @@ dir_filelist() {
fi
}
# if only one file is specified and it is .cpio file then use it direct as fs
# if a directory is specified then add all files in given direcotry to fs
# if a regular file is specified assume it is in gen_init_cpio format
input_file() {
source="$1"
if [ -f "$1" ]; then
# If a regular file is specified, assume it is in
# gen_init_cpio format
header "$1"
is_cpio="$(echo "$1" | sed 's/^.*\.cpio\(\..*\)\{0,1\}/cpio/')"
if [ $2 -eq 0 -a ${is_cpio} = "cpio" ]; then
cpio_file=$1
echo "$1" | grep -q '^.*\.cpio\..*' && is_cpio_compressed="compressed"
[ -n "$dep_list" ] && echo "$1" >> $dep_list
return 0
fi
print_mtime "$1" >> $cpio_list
cat "$1" >> $cpio_list
if [ -n "$dep_list" ]; then
@ -187,6 +178,7 @@ input_file() {
done
fi
elif [ -d "$1" ]; then
# If a directory is specified then add all files in it to fs
dir_filelist "$1"
else
echo " ${prog}: Cannot open '$1'" >&2
@ -198,12 +190,8 @@ prog=$0
root_uid=0
root_gid=0
dep_list=
cpio_file=
cpio_list=$(mktemp ${TMPDIR:-/tmp}/cpiolist.XXXXXX)
output="/dev/stdout"
output_file="/dev/stdout"
is_cpio_compressed=
compr="gzip -n -9 -f"
while [ $# -gt 0 ]; do
arg="$1"
@ -214,28 +202,8 @@ while [ $# -gt 0 ]; do
echo "deps_initramfs := \\" > $dep_list
shift
;;
"-o") # generate compressed cpio image named $1
output_file="$1"
output=$cpio_list
echo "$output_file" | grep -q "\.gz$" \
&& [ -x "`which gzip 2> /dev/null`" ] \
&& compr="gzip -n -9 -f"
echo "$output_file" | grep -q "\.bz2$" \
&& [ -x "`which bzip2 2> /dev/null`" ] \
&& compr="bzip2 -9 -f"
echo "$output_file" | grep -q "\.lzma$" \
&& [ -x "`which lzma 2> /dev/null`" ] \
&& compr="lzma -9 -f"
echo "$output_file" | grep -q "\.xz$" \
&& [ -x "`which xz 2> /dev/null`" ] \
&& compr="xz --check=crc32 --lzma2=dict=1MiB"
echo "$output_file" | grep -q "\.lzo$" \
&& [ -x "`which lzop 2> /dev/null`" ] \
&& compr="lzop -9 -f"
echo "$output_file" | grep -q "\.lz4$" \
&& [ -x "`which lz4 2> /dev/null`" ] \
&& compr="lz4 -l -9 -f"
echo "$output_file" | grep -q "\.cpio$" && compr="cat"
"-o") # generate cpio image named $1
output="$1"
shift
;;
"-u") # map $1 to uid=0 (root)
@ -258,34 +226,21 @@ while [ $# -gt 0 ]; do
unknown_option
;;
*) # input file/dir - process it
input_file "$arg" "$#"
input_file "$arg"
;;
esac
;;
esac
done
# If output_file is set we will generate cpio archive and compress it
# If output_file is set we will generate cpio archive
# we are careful to delete tmp files
if [ -z ${cpio_file} ]; then
timestamp=
if test -n "$KBUILD_BUILD_TIMESTAMP"; then
timestamp="$(date -d"$KBUILD_BUILD_TIMESTAMP" +%s || :)"
if test -n "$timestamp"; then
timestamp="-t $timestamp"
fi
timestamp=
if test -n "$KBUILD_BUILD_TIMESTAMP"; then
timestamp="$(date -d"$KBUILD_BUILD_TIMESTAMP" +%s || :)"
if test -n "$timestamp"; then
timestamp="-t $timestamp"
fi
cpio_tfile="$(mktemp ${TMPDIR:-/tmp}/cpiofile.XXXXXX)"
usr/gen_init_cpio $timestamp ${cpio_list} > ${cpio_tfile}
else
cpio_tfile=${cpio_file}
fi
rm ${cpio_list}
if [ "${is_cpio_compressed}" = "compressed" ]; then
cat ${cpio_tfile} > ${output_file}
else
(cat ${cpio_tfile} | ${compr} - > ${output_file}) \
|| (rm -f ${output_file} ; false)
fi
[ -z ${cpio_file} ] && rm ${cpio_tfile}
exit 0
usr/gen_init_cpio $timestamp $cpio_list > $output
rm $cpio_list

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@ -22,12 +22,9 @@
in the ELF header, as required by certain architectures.
*/
#include <linux/stringify.h>
#include <asm-generic/vmlinux.lds.h>
.section .init.ramfs,"a"
__irf_start:
.incbin __stringify(INITRAMFS_IMAGE)
.incbin "usr/initramfs_inc_data"
__irf_end:
.section .init.ramfs.info,"a"
.globl __initramfs_size