initramfs: generate dependency list and cpio at the same time

Currently, this script is run twice, for the dependency list, and then
for the cpio archive.

The first one is re-run every time although its build log is suppressed
so nobody notices it.

Make it work more efficiently by generating the cpio and the dependency
list at the same time.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

usr/Makefile

@@ -39,7 +39,7 @@ ifneq ($(wildcard $(obj)/$(datafile_d_y)),)
 endif
 
 quiet_cmd_initfs = GEN     $@
-      cmd_initfs = $(CONFIG_SHELL) $< -o $@ $(ramfs-args) $(ramfs-input)
+      cmd_initfs = $(CONFIG_SHELL) $< -o $@ -l $(obj)/$(datafile_d_y) $(ramfs-args) $(ramfs-input)
 
 targets := $(datafile_y)
 
@@ -52,7 +52,6 @@ $(deps_initramfs): ;
 # 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
-	$(Q)$< -l $(ramfs-input) > $(obj)/$(datafile_d_y)
 	$(call if_changed,initfs)
 
 subdir-$(CONFIG_UAPI_HEADER_TEST) += include

usr/gen_initramfs.sh

@@ -15,9 +15,10 @@ set -e
 usage() {
 cat << EOF
 Usage:
-$0 [-o <file>] [-u <uid>] [-g <gid>] {-d | <cpio_source>} ...
+$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
+	-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
 		       directory.  "squash" forces all files to uid 0.
@@ -42,11 +43,6 @@ field() {
 	shift $1 ; echo $1
 }
 
-list_default_initramfs() {
-	# echo usr/kinit/kinit
-	:
-}
-
 default_initramfs() {
 	cat <<-EOF >> ${output}
 		# This is a very simple, default initramfs
@@ -81,10 +77,6 @@ filetype() {
 	return 0
 }
 
-list_print_mtime() {
-	:
-}
-
 print_mtime() {
 	local my_mtime="0"
 
@@ -97,10 +89,10 @@ print_mtime() {
 }
 
 list_parse() {
-	if [ -L "$1" ]; then
+	if [ -z "$dep_list" -o -L "$1" ]; then
 		return
 	fi
-	echo "$1" | sed 's/:/\\:/g; s/$/ \\/'
+	echo "$1" | sed 's/:/\\:/g; s/$/ \\/' >> $dep_list
 }
 
 # for each file print a line in following format
@@ -161,28 +153,25 @@ unknown_option() {
 	exit 1
 }
 
-list_header() {
-	:
-}
-
 header() {
 	printf "\n#####################\n# $1\n" >> ${output}
 }
 
 # process one directory (incl sub-directories)
 dir_filelist() {
-	${dep_list}header "$1"
+	header "$1"
 
 	srcdir=$(echo "$1" | sed -e 's://*:/:g')
 	dirlist=$(find "${srcdir}" -printf "%p %m %U %G\n" | LANG=C sort)
 
 	# If $dirlist is only one line, then the directory is empty
 	if [  "$(echo "${dirlist}" | wc -l)" -gt 1 ]; then
-		${dep_list}print_mtime "$1"
+		print_mtime "$1"
 
 		echo "${dirlist}" | \
 		while read x; do
-			${dep_list}parse ${x}
+			list_parse $x
+			parse $x
 		done
 	fi
 }
@@ -193,22 +182,21 @@ dir_filelist() {
 input_file() {
 	source="$1"
 	if [ -f "$1" ]; then
-		${dep_list}header "$1"
+		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"
-			[ ! -z ${dep_list} ] && echo "$1"
+			[ -n "$dep_list" ] && echo "$1" >> $dep_list
 			return 0
 		fi
-		if [ -z ${dep_list} ]; then
-			print_mtime "$1" >> ${output}
-			cat "$1"         >> ${output}
-		else
-		        echo "$1 \\"
+		print_mtime "$1" >> ${output}
+		cat "$1"         >> ${output}
+		if [ -n "$dep_list" ]; then
+		        echo "$1 \\"  >> $dep_list
 			cat "$1" | while read type dir file perm ; do
 				if [ "$type" = "file" ]; then
-					echo "$file \\";
+					echo "$file \\" >> $dep_list
 				fi
 			done
 		fi
@@ -231,44 +219,40 @@ output_file=""
 is_cpio_compressed=
 compr="gzip -n -9 -f"
 
-arg="$1"
-case "$arg" in
-	"-l")	# files included in initramfs - used by kbuild
-		dep_list="list_"
-		echo "deps_initramfs := \\"
-		shift
-		;;
-	"-o")	# generate compressed cpio image named $1
-		shift
-		output_file="$1"
-		cpio_list="$(mktemp ${TMPDIR:-/tmp}/cpiolist.XXXXXX)"
-		output=${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"
-		shift
-		;;
-esac
 while [ $# -gt 0 ]; do
 	arg="$1"
 	shift
 	case "$arg" in
+		"-l")	# files included in initramfs - used by kbuild
+			dep_list="$1"
+			echo "deps_initramfs := \\" > $dep_list
+			shift
+			;;
+		"-o")	# generate compressed cpio image named $1
+			output_file="$1"
+			cpio_list="$(mktemp ${TMPDIR:-/tmp}/cpiolist.XXXXXX)"
+			output=${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"
+			shift
+			;;
 		"-u")	# map $1 to uid=0 (root)
 			root_uid="$1"
 			[ "$root_uid" = "-1" ] && root_uid=$(id -u || echo 0)
@@ -280,7 +264,7 @@ while [ $# -gt 0 ]; do
 			shift
 			;;
 		"-d")	# display default initramfs list
-			${dep_list}default_initramfs
+			default_initramfs
 			;;
 		"-h")
 			usage