start-rpi-sdk

#!/bin/bash

SDK_PATH=$1

function usage {
	echo "Usage: start-sdk-rpi SDK_PATH"
}

function mountall {
	echo "Mounting directories..."
	mount -t proc proc $SDK_PATH/proc
	mount -t sysfs sysfs $SDK_PATH/sys
	mount -t devtmpfs udev $SDK_PATH/dev
	mount -t devpts devpts $SDK_PATH/dev/pts
}

function pre_start {
	local abspath=$(cd $SDK_PATH/.sdk; pwd -P)
	if [ -z "`grep $abspath /proc/mounts`" ]; then
		mountall
		mount -t tmpfs tmpfs $SDK_PATH/.sdk
	fi
	cp /etc/resolv.conf $SDK_PATH/etc/.
	cp /etc/hosts $SDK_PATH/etc/.
	touch $SDK_PATH/.sdk/$$
}

function umountall {
	echo "Umounting directories..."
	umount $SDK_PATH/dev/pts
	umount $SDK_PATH/dev
	umount $SDK_PATH/sys
	umount $SDK_PATH/proc
}

function post_exit {
	local abspath=$(cd $SDK_PATH/.sdk; pwd -P)
	if [ -z "`grep $abspath /proc/mounts`" ]; then
		# Should not happen, do nothing
		return
	fi

	rm -f $SDK_PATH/.sdk/$$
	if [ -z "`ls $SDK_PATH/.sdk`" ]; then
		umount $SDK_PATH/.sdk
		umountall
	fi
}

if [ `id -u` -ne 0 ]; then
	echo "You must have root permissions to run this script. Trust me!"
	exit
fi

if [ -z $SDK_PATH ] || [ "$SDK_PATH" = "-h" ]; then
	usage
	exit
fi

if [ ! -x $SDK_PATH/bin/su ]; then
	echo "Error: SDK_PATH is not a valid sdk directory."
	usage
	exit
fi

pre_start

trap "post_exit; exit" SIGINT SIGTERM SIGHUP

chroot $SDK_PATH /bin/su -l pi

post_exit