initramfs-tools/init

#!/bin/sh

echo "Loading, please wait..."

[ -d /dev ] || mkdir -m 0755 /dev
[ -d /root ] || mkdir -m 0700 /root
[ -d /sys ] || mkdir /sys
[ -d /proc ] || mkdir /proc
[ -d /tmp ] || mkdir /tmp
mkdir -p /var/lock
mount -t sysfs -o nodev,noexec,nosuid none /sys
mount -t proc -o nodev,noexec,nosuid none /proc

# Note that this only becomes /dev on the real filesystem if udev's scripts
# are used; which they will be, but it's worth pointing out
tmpfs_size="10M"
if [ -e /etc/udev/udev.conf ]; then
	. /etc/udev/udev.conf
fi
if ! mount -t devtmpfs -o mode=0755 none /dev; then
	echo "W: devtmpfs not available, falling back to tmpfs for /dev"
	mount -t tmpfs -o size=$tmpfs_size,mode=0755 udev /dev
	[ -e /dev/console ] || mknod -m 0600 /dev/console c 5 1
	[ -e /dev/null ] || mknod /dev/null c 1 3
fi
mkdir /dev/pts
mount -t devpts -o noexec,nosuid,gid=5,mode=0620 none /dev/pts || true
> /dev/.initramfs-tools
mkdir /dev/.initramfs

# Export the dpkg architecture
export DPKG_ARCH=
. /conf/arch.conf

# Set modprobe env
export MODPROBE_OPTIONS="-qb"

# Export relevant variables
export ROOT=
export ROOTDELAY=
export ROOTFLAGS=
export ROOTFSTYPE=
export IP=
export BOOT=
export BOOTIF=
export UBIMTD=
export break=
export init=/sbin/init
export quiet=n
export readonly=y
export rootmnt=/root
export debug=
export panic=
export blacklist=
export resume=
export resume_offset=

# Bring in the main config
. /conf/initramfs.conf
for conf in conf/conf.d/*; do
	[ -f ${conf} ] && . ${conf}
done
. /scripts/functions

# Parse command line options
for x in $(cat /proc/cmdline); do
	case $x in
	init=*)
		init=${x#init=}
		;;
	root=*)
		ROOT=${x#root=}
		case $ROOT in
		LABEL=*)
			ROOT="${ROOT#LABEL=}"

			# support any / in LABEL= path (escape to \x2f)
			case "${ROOT}" in
			*/*)
			if command -v sed >/dev/null 2>&1; then
				ROOT="$(echo ${ROOT} | sed 's,/,\\x2f,g')"
			else
				if [ "${ROOT}" != "${ROOT#/}" ]; then
					ROOT="\x2f${ROOT#/}"
				fi
				if [ "${ROOT}" != "${ROOT%/}" ]; then
					ROOT="${ROOT%/}\x2f"
				fi
				IFS='/'
				newroot=
				for s in $ROOT; do
					newroot="${newroot:+${newroot}\\x2f}${s}"
				done
				unset IFS
				ROOT="${newroot}"
			fi
			esac
			ROOT="/dev/disk/by-label/${ROOT}"
			;;
		UUID=*)
			ROOT="/dev/disk/by-uuid/${ROOT#UUID=}"
			;;
		/dev/nfs)
			[ -z "${BOOT}" ] && BOOT=nfs
			;;
		esac
		;;
	rootflags=*)
		ROOTFLAGS="-o ${x#rootflags=}"
		;;
	rootfstype=*)
		ROOTFSTYPE="${x#rootfstype=}"
		;;
	rootdelay=*)
		ROOTDELAY="${x#rootdelay=}"
		case ${ROOTDELAY} in
		*[![:digit:].]*)
			ROOTDELAY=
			;;
		esac
		;;
	nfsroot=*)
		NFSROOT="${x#nfsroot=}"
		;;
	ip=*)
		IP="${x#ip=}"
		;;
	boot=*)
		BOOT=${x#boot=}
		;;
	ubi.mtd=*)
		UBIMTD=${x#ubi.mtd=}
		;;
	resume=*)
		RESUME="${x#resume=}"
		;;
	resume_offset=*)
		resume_offset="${x#resume_offset=}"
		;;
	noresume)
		noresume=y
		;;
	panic=*)
		panic="${x#panic=}"
		case ${panic} in
		*[![:digit:].]*)
			panic=
			;;
		esac
		;;
	quiet)
		quiet=y
		;;
	ro)
		readonly=y
		;;
	rw)
		readonly=n
		;;
	debug)
		debug=y
		quiet=n
		exec >/dev/.initramfs/initramfs.debug 2>&1
		set -x
		;;
	debug=*)
		debug=y
		quiet=n
		set -x
		;;
	break=*)
		break=${x#break=}
		;;
	break)
		break=premount
		;;
	blacklist=*)
		blacklist=${x#blacklist=}
		;;
	netconsole=*)
		netconsole=${x#netconsole=}
		;;
	BOOTIF=*)
		BOOTIF=${x#BOOTIF=}
		;;
	esac
done

if [ -n "${noresume}" ]; then
	export noresume
	unset resume
else
	resume=${RESUME:-}
fi

[ -n "${netconsole}" ] && modprobe netconsole netconsole="${netconsole}"

maybe_break top

# Don't do log messages here to avoid confusing usplash
run_scripts /scripts/init-top

maybe_break modules
[ "$quiet" != "y" ] && log_begin_msg "Loading essential drivers"
load_modules
[ "$quiet" != "y" ] && log_end_msg

maybe_break premount
[ "$quiet" != "y" ] && log_begin_msg "Running /scripts/init-premount"
run_scripts /scripts/init-premount
[ "$quiet" != "y" ] && log_end_msg

maybe_break mount
log_begin_msg "Mounting root file system"
. /scripts/${BOOT}
parse_numeric ${ROOT}
maybe_break mountroot
mountroot
log_end_msg

maybe_break bottom
[ "$quiet" != "y" ] && log_begin_msg "Running /scripts/init-bottom"
run_scripts /scripts/init-bottom
[ "$quiet" != "y" ] && log_end_msg

# Move virtual filesystems over to the real filesystem
mount -n -o move /sys ${rootmnt}/sys
mount -n -o move /proc ${rootmnt}/proc

# Check init bootarg
if [ -n "${init}" ] && [ ! -x "${rootmnt}${init}" ]; then
	echo "Target filesystem doesn't have ${init}."
	init=
fi

# Search for valid init
if [ -z "${init}" ] ; then
	for init in /sbin/init /etc/init /bin/init /bin/sh; do
		if [ ! -x "${rootmnt}${init}" ]; then
			continue
		fi
		break
	done
fi

# No init on rootmount
if [ ! -x "${rootmnt}${init}" ]; then
	panic "No init found. Try passing init= bootarg."
fi

maybe_break init

# don't leak too much of env - some init(8) don't clear it
# (keep init, rootmnt)
unset debug
unset MODPROBE_OPTIONS
unset DPKG_ARCH
unset ROOTFLAGS
unset ROOTFSTYPE
unset ROOTDELAY
unset ROOT
unset IP
unset BOOT
unset BOOTIF
unset UBIMTD
unset blacklist
unset break
unset noresume
unset panic
unset quiet
unset readonly
unset resume
unset resume_offset

# Chain to real filesystem
exec run-init ${rootmnt} ${init} "$@" <${rootmnt}/dev/console >${rootmnt}/dev/console
panic "Could not execute run-init."