Step1: build with busybox.

Signed-off-by: Chen Wang <wangchen20@iscas.ac.cn>

package/target-finalize/ifupdown-scripts/S40network

@@ -0,0 +1,30 @@
+#!/bin/sh
+#
+# Start the network....
+#
+
+# Debian ifupdown needs the /run/network lock directory
+mkdir -p /run/network
+
+case "$1" in
+  start)
+	printf "Starting network: "
+	/sbin/ifup -a
+	[ $? = 0 ] && echo "OK" || echo "FAIL"
+	;;
+  stop)
+	printf "Stopping network: "
+	/sbin/ifdown -a
+	[ $? = 0 ] && echo "OK" || echo "FAIL"
+	;;
+  restart|reload)
+	"$0" stop
+	"$0" start
+	;;
+  *)
+	echo "Usage: $0 {start|stop|restart}"
+	exit 1
+esac
+
+exit $?
+

package/target-finalize/ifupdown-scripts/network/if-pre-up.d/wait_iface

@@ -0,0 +1,21 @@
+#!/bin/sh
+
+# In case we have a slow-to-appear interface (e.g. eth-over-USB),
+# and we need to configure it, wait until it appears, but not too
+# long either. IF_WAIT_DELAY is in seconds.
+
+if [ "${IF_WAIT_DELAY}" -a ! -e "/sys/class/net/${IFACE}" ]; then
+    printf "Waiting for interface %s to appear" "${IFACE}"
+    while [ ${IF_WAIT_DELAY} -gt 0 ]; do
+        if [ -e "/sys/class/net/${IFACE}" ]; then
+            printf "\n"
+            exit 0
+        fi
+        sleep 1
+        printf "."
+        : $((IF_WAIT_DELAY -= 1))
+    done
+    printf " timeout!\n"
+    exit 1
+fi
+

package/target-finalize/ifupdown-scripts/nfs_check

@@ -0,0 +1,20 @@
+#!/bin/sh
+
+# This allows NFS booting to work while also being able to configure
+# the network interface via DHCP when not NFS booting.  Otherwise, a
+# NFS booted system will likely hang during DHCP configuration.
+
+# Attempting to configure the network interface used for NFS will
+# initially bring that network down.  Since the root filesystem is
+# accessed over this network, the system hangs.
+
+# This script is run by ifup and will attempt to detect if a NFS root
+# mount uses the interface to be configured (IFACE), and if so does
+# not configure it.  This should allow the same build to be disk/flash
+# booted or NFS booted.
+
+nfsip=`sed -n '/^[^ ]*:.* \/ nfs.*[ ,]addr=\([0-9.]\+\).*/s//\1/p' /proc/mounts`
+if [ -n "$nfsip" ] && ip route get to "$nfsip" | grep -q "dev $IFACE"; then
+	echo Skipping $IFACE, used for NFS from $nfsip
+	exit 1
+fi