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Commit d39a206b authored by Sam Ravnborg's avatar Sam Ravnborg
Browse files

kbuild: rebuild initramfs if content of initramfs changes 



initramfs.cpio.gz being build in usr/ and included in the
kernel was not rebuild when the included files changed.

To fix this the following was done:
- let gen_initramfs.sh generate a list of files and directories included
  in the initramfs
- gen_initramfs generate the gzipped cpio archive so we could simplify
  the kbuild file (Makefile)
- utilising the kbuild infrastructure so when uid/gid root mapping changes
  the initramfs will be rebuild

With this change we have a much more robust initramfs generation.

Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
parent d9df92e2

scripts/gen_initramfs_list.sh

+152 −73
Original line number Diff line number Diff line 
#!/bin/bash

# Copyright (C) Martin Schlemmer <azarah@nosferatu.za.org>

# Released under the terms of the GNU GPL

#

# Generate a newline separated list of entries from the file/directory

# supplied as an argument.

# Copyright (c) 2006           Sam Ravnborg <sam@ravnborg.org>

#

# If a file/directory is not supplied then generate a small dummy file.

#

# The output is suitable for gen_init_cpio built from usr/gen_init_cpio.c.

# Released under the terms of the GNU GPL

#

# Generate a cpio packed initramfs. It uses gen_init_cpio to generate

# the cpio archive, and gzip to pack it.

# The script may also be used to generate the inputfile used for gen_init_cpio

# This script assumes that gen_init_cpio is located in usr/ directory



# error out on errors

set -e



usage() {

cat << EOF

Usage:

$0 [-o <file>] [-u <uid>] [-g <gid>] {-d | <cpio_source>} ...

	-o <file>      Create gzipped initramfs file named <file> using

	               gen_init_cpio and gzip

	-u <uid>       User ID to map to user ID 0 (root).

	               <uid> is only meaningful if <cpio_source>

	               is a directory.

	-g <gid>       Group ID to map to group ID 0 (root).

	               <gid> is only meaningful if <cpio_source>

	               is a directory.

	<cpio_source>  File list or directory for cpio archive.

	               If <cpio_source> is a .cpio file it will be used

		       as direct input to initramfs.

	-d             Output the default cpio list.



All options except -o and -l may be repeated and are interpreted

sequentially and immediately.  -u and -g states are preserved across

<cpio_source> options so an explicit "-u 0 -g 0" is required

to reset the root/group mapping.

EOF

}



list_default_initramfs() {

	# echo usr/kinit/kinit

	:

}



default_initramfs() {

	cat <<-EOF

	cat <<-EOF >> ${output}

		# This is a very simple, default initramfs



		dir /dev 0755 0 0

		nod /dev/console 0600 0 0 c 5 1

		dir /root 0700 0 0

		# file /kinit usr/kinit/kinit 0755 0 0

		# slink /init kinit 0755 0 0

	EOF

}
@@ -42,18 +75,28 @@ filetype() { 
	return 0

}



list_print_mtime() {

	:

}



print_mtime() {

	local argv1="$1"

	local my_mtime="0"



	if [ -e "${argv1}" ]; then

		my_mtime=$(find "${argv1}" -printf "%T@\n" | sort -r | head -n 1)

	if [ -e "$1" ]; then

		my_mtime=$(find "$1" -printf "%T@\n" | sort -r | head -n 1)

	fi



	echo "# Last modified: ${my_mtime}"

	echo

	echo "# Last modified: ${my_mtime}" >> ${output}

	echo "" >> ${output}

}



list_parse() {

	echo "$1 \\"

}



# for each file print a line in following format

# <filetype> <name> <path to file> <octal mode> <uid> <gid>

# for links, devices etc the format differs. See gen_init_cpio for details

parse() {

	local location="$1"

	local name="${location/${srcdir}//}"
@@ -99,80 +142,112 @@ parse() { 
			;;

	esac



	echo "${str}"

	echo "${str}" >> ${output}



	return 0

}



usage() {

	printf    "Usage:\n"

	printf    "$0 [ [-u <root_uid>] [-g <root_gid>] [-d | <cpio_source>] ] . . .\n"

	printf    "\n"

	printf -- "-u <root_uid>  User ID to map to user ID 0 (root).\n"

	printf    "               <root_uid> is only meaningful if <cpio_source>\n"

	printf    "               is a directory.\n"

	printf -- "-g <root_gid>  Group ID to map to group ID 0 (root).\n"

	printf    "               <root_gid> is only meaningful if <cpio_source>\n"

	printf    "               is a directory.\n"

	printf    "<cpio_source>  File list or directory for cpio archive.\n"

	printf    "               If <cpio_source> is not provided then a\n"

	printf    "               a default list will be output.\n"

	printf -- "-d             Output the default cpio list.  If no <cpio_source>\n"

	printf    "               is given then the default cpio list will be output.\n"

	printf    "\n"

	printf    "All options may be repeated and are interpreted sequentially\n"

	printf    "and immediately.  -u and -g states are preserved across\n"

	printf    "<cpio_source> options so an explicit \"-u 0 -g 0\" is required\n"

	printf    "to reset the root/group mapping.\n"

unknown_option() {

	printf "ERROR: unknown option \"$arg\"\n" >&2

	printf "If the filename validly begins with '-', " >&2

	printf "then it must be prefixed\n" >&2

	printf "by './' so that it won't be interpreted as an option." >&2

	printf "\n" >&2

	usage >&2

	exit 1

}



build_list() {

	printf "\n#####################\n# $cpio_source\n"

list_header() {

	echo "deps_initramfs := \\"

}



header() {

	printf "\n#####################\n# $1\n" >> ${output}

}



	if [ -f "$cpio_source" ]; then

		print_mtime "$cpio_source"

		cat "$cpio_source"

	elif [ -d "$cpio_source" ]; then

		srcdir=$(echo "$cpio_source" | sed -e 's://*:/:g')

# process one directory (incl sub-directories)

dir_filelist() {

	${dep_list}header "$1"



	srcdir=$(echo "$1" | sed -e 's://*:/:g')

	dirlist=$(find "${srcdir}" -printf "%p %m %U %G\n" 2>/dev/null)



	# If $dirlist is only one line, then the directory is empty

	if [  "$(echo "${dirlist}" | wc -l)" -gt 1 ]; then

			print_mtime "$cpio_source"

		${dep_list}print_mtime "$1"



		echo "${dirlist}" | \

		while read x; do

				parse ${x}

			${dep_list}parse ${x}

		done

	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_initramfs format

input_file() {

	source="$1"

	if [ -f "$1" ]; then

		${dep_list}header "$1"

		is_cpio="$(echo "$1" | sed 's/^.*\.cpio/cpio/')"

		if [ $2 -eq 0 -a ${is_cpio} == "cpio" ]; then

			cpio_file=$1

			[ ! -z ${dep_list} ] && echo "$1"

			return 0

		fi

		if [ -z ${dep_list} ]; then

			print_mtime "$1" >> ${output}

			cat "$1"         >> ${output}

		else

			# Failsafe in case directory is empty

			default_initramfs

			grep ^file "$1" | cut -d ' ' -f 3

		fi

	elif [ -d "$1" ]; then

		dir_filelist "$1"

	else

		echo "  $0: Cannot open '$cpio_source'" >&2

		echo "  ${prog}: Cannot open '$1'" >&2

		exit 1

	fi

}





prog=$0

root_uid=0

root_gid=0

dep_list=

cpio_file=

cpio_list=

output="/dev/stdout"

output_file=""



arg="$1"

case "$arg" in

	"-l")	# files included in initramfs - used by kbuild

		dep_list="list_"

		shift

		;;

	"-o")	# generate gzipped cpio image named $1

		shift

		output_file="$1"

		cpio_list="$(mktemp ${TMPDIR:-/tmp}/cpiolist.XXXXXX)"

		output=${cpio_list}

		shift

		;;

esac

while [ $# -gt 0 ]; do

	arg="$1"

	shift

	case "$arg" in

		"-u")

		"-u")	# map $1 to uid=0 (root)

			root_uid="$1"

			shift

			;;

		"-g")

		"-g")	# map $1 to gid=0 (root)

			root_gid="$1"

			shift

			;;

		"-d")

		"-d")	# display default initramfs list

			default_list="$arg"

			default_initramfs

			${dep_list}default_initramfs

			;;

		"-h")

			usage
@@ -181,23 +256,27 @@ while [ $# -gt 0 ]; do 
		*)

			case "$arg" in

				"-"*)

					printf "ERROR: unknown option \"$arg\"\n" >&2

					printf "If the filename validly begins with '-', then it must be prefixed\n" >&2

					printf "by './' so that it won't be interpreted as an option." >&2

					printf "\n" >&2

					usage >&2

					exit 1

					unknown_option

					;;

				*)

					cpio_source="$arg"

					build_list

				*)	# input file/dir - process it

					input_file "$arg" "$#"

					;;

			esac

			;;

	esac

done



# spit out the default cpio list if a source hasn't been specified

[ -z "$cpio_source" -a -z "$default_list" ] && default_initramfs



# If output_file is set we will generate cpio archive and gzip it

# we are carefull to delete tmp files

if [ ! -z ${output_file} ]; then

	if [ -z ${cpio_file} ]; then

		cpio_tfile="$(mktemp ${TMPDIR:-/tmp}/cpiofile.XXXXXX)"

		usr/gen_init_cpio ${cpio_list} > ${cpio_tfile}

	else

		cpio_tfile=${cpio_file}

	fi

	rm ${cpio_list}

	cat ${cpio_tfile} | gzip -f -9 - > ${output_file}

	[ -z ${cpio_file} ] && rm ${cpio_tfile}

fi

exit 0

usr/Makefile

+37 −54
Original line number Diff line number Diff line 
#

# kbuild file for usr/ - including initramfs image

#



obj-y := initramfs_data.o



hostprogs-y  := gen_init_cpio

klibcdirs:;



clean-files := initramfs_data.cpio.gz initramfs_list

# Generate builtin.o based on initramfs_data.o

obj-y := 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



ifdef CONFIG_INITRAMFS_ROOT_UID

gen_initramfs_args += -u $(CONFIG_INITRAMFS_ROOT_UID)

endif



ifdef CONFIG_INITRAMFS_ROOT_GID

gen_initramfs_args += -g $(CONFIG_INITRAMFS_ROOT_GID)

endif



# The $(shell echo $(CONFIG_INITRAMFS_SOURCE)) is to remove the

# gratuitous begin and end quotes from the Kconfig string type.

# Internal, escaped quotes in the Kconfig string will loose the

# escape and become active quotes.

quotefixed_initramfs_source := $(shell echo $(CONFIG_INITRAMFS_SOURCE))



filechk_initramfs_list = $(CONFIG_SHELL) \

 $(srctree)/scripts/gen_initramfs_list.sh $(gen_initramfs_args) $(quotefixed_initramfs_source)



$(obj)/initramfs_list: $(obj)/Makefile FORCE

	$(call filechk,initramfs_list)



quiet_cmd_cpio = CPIO    $@

      cmd_cpio = ./$< $(obj)/initramfs_list > $@





# Check if the INITRAMFS_SOURCE is a cpio archive

ifneq (,$(findstring .cpio,$(quotefixed_initramfs_source)))



# INITRAMFS_SOURCE has a cpio archive - verify that it's a single file

ifneq (1,$(words $(quotefixed_initramfs_source)))

$(error Only a single file may be specified in CONFIG_INITRAMFS_SOURCE (="$(quotefixed_initramfs_source)") when a cpio archive is directly specified.)

endif

# Now use the cpio archive directly

initramfs_data_cpio = $(quotefixed_initramfs_source)

targets += $(quotefixed_initramfs_source)



else



# INITRAMFS_SOURCE is not a cpio archive - create one

$(obj)/initramfs_data.cpio: $(obj)/gen_init_cpio \

                            $(initramfs-y) $(obj)/initramfs_list FORCE

	$(call if_changed,cpio)



targets += initramfs_data.cpio

initramfs_data_cpio = $(obj)/initramfs_data.cpio

#####

# 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)), \

                    $(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)) \

        $(ramfs-input)



# .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





$(obj)/initramfs_data.cpio.gz: $(initramfs_data_cpio) FORCE

	$(call if_changed,gzip)



targets += initramfs_data.cpio.gz

quiet_cmd_initfs = GEN     $@

      cmd_initfs = $(initramfs) -o $@ $(ramfs-args) $(ramfs-input)



targets := initramfs_data.cpio.gz

$(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)