abuild/initramfs-init

#!/bin/ash

VERSION=1.9.1-pre0
NEWROOT=/newroot
SINGLEMODE=no

# basic environment
export PATH=/usr/bin:/bin:/usr/sbin:/sbin

# basic mounts
mount -t proc -o noexec,nosuid,nodev proc /proc
mount -t sysfs -o noexec,nosuid,nodev sysfs /sys

# some helpers
ebegin() {
	echo -n " * $*: "
}
eend() {
	local msg
	if [ "$1" = 0 ] || [ $# -lt 1 ] ; then
		echo "ok."
	else
		shift
		echo "failed. $*"
		echo "Emergency recovery shell started."
		exec /bin/busybox sh
	fi
}

scan_drivers() {
	if [ "$AUTODETECT" != no ] ; then
		find /sys -name modalias | xargs sort | while read a ; do
			modprobe $a 2>/dev/null \
				|| echo $a >> /tmp/hwdrivers.failed
		done
	fi
}

# gotta start from somewhere :)
echo "Starting Alpine $VERSION"

# read the kernel options
for i in `cat /proc/cmdline` ; do
	case $i in
		s|single|1)
			SINGLEMODE=yes ;;
		modules=*)
			MODULES="`echo ${i#modules=} | tr ',' ' '`";;
		noautodetect)
			AUTODETECT=no;;
		*=*)    eval KOPT_$i ;;
		*)      eval KOPT_$i=yes ;;
	esac
done

ALPINE_DEV=${KOPT_alpine_dev%%:*}
ALPINE_MNT=/media/$ALPINE_DEV

# hide kernel messages
dmesg -n 1

# setup /dev
ebegin "Starting mdev"
mount -t tmpfs -o exec,nosuid,mode=0755 mdev /dev
mknod -m 666 /dev/null c 1 3
ln -s sr0 /dev/cdrom
echo "/sbin/mdev" > /proc/sys/kernel/hotplug
mdev -s
RC=$?
[ -d /dev/pts ] || mkdir -m 755 /dev/pts
[ -c /dev/ptmx ] || mknod -m 666 /dev/ptmx c 5 2
mount -t devpts -o gid=5,mode=0620,noexec,nosuid devpts /dev/pts
[ -d /dev/shm ] || mkdir /dev/shm
mount -t tmpfs -o nodev,nosuid,noexec shm /dev/shm
eend $RC

# load available drivers to get access to modloop media
ebegin "Loading boot drivers"
[ "$MODULES" ] && modprobe $MODULES 2> /dev/null
scan_drivers
scan_drivers
eend 0

# locate boot media and mount it
ebegin "Mounting boot media"
mount $ALPINE_MNT >/dev/null 2>&1
eend $?
ebegin "Mounting loopback device for kernel modules"
modprobe loop
mount -o loop,ro -t cramfs /media/$ALPINE_DEV/$(dirname ${KOPT_BOOT_IMAGE:-""})/modloop.cmg /.modloop
rc=$?
if [ "$rc" = 0 ]; then
	rm -rf /lib/modules
	ln -sf /.modloop/modules /lib
fi
if [ -d $ALPINE_MNT/firmware ]; then
	mkdir -p /lib/firmware
	cp -a $ALPINE_MNT/firmware/* /lib/firmware/
fi
eend $?

# early console?
if [ "$SINGLEMODE" = "yes" ]; then
	echo "Entering single mode. Type 'exit' to continue booting."
	sh
fi

# more drivers
ebegin "Loading hardware drivers"
scan_drivers
eend 0

# install new root
ebegin "Installing packets to root filesystem"
mount -t tmpfs -o size=50M tmpfs $NEWROOT
apk create --root /newroot
apk add --root /newroot --repository /media/cdrom/apks
eend $?

# switch over to new root
cat /proc/mounts | while read DEV DIR TYPE OPTS ; do
	if [ "$DIR" != "/" -a "$DIR" != "$NEWROOT" -a -d "$DIR" ]; then
		mkdir -p $NEWROOT/$DIR
		mount -o move $DIR $NEWROOT/$DIR
	fi
done
sync
exec /bin/busybox switch_root $NEWROOT /sbin/init $KOPT_init_args || exec /bin/busybox sh