Add a script to modify miniomaha server address in initrd.uimg

BUG=none
TEST=none

Change-Id: Iee7d4ba516ed77b37ce932a90fef1ed24b1bd8d5
Reviewed-on: https://gerrit.chromium.org/gerrit/24295
Reviewed-by: Chun-Ta Lin <itspeter@chromium.org>
Tested-by: Chun-Ta Lin <itspeter@chromium.org>
diff --git a/modify_netboot_ip.sh b/modify_netboot_ip.sh
new file mode 100755
index 0000000..6df9469
--- /dev/null
+++ b/modify_netboot_ip.sh
@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+if [ -z "$1" ]; then
+	echo "Usage: modify_netboot_ip.sh <initrd.uimg>"
+	exit 1
+fi
+dd if="$1" of="rootfs.gz" bs=64 skip=1
+gunzip -d "rootfs.gz"
+rm -rf r
+mkdir r
+sudo mount -o loop rootfs r
+sudo vim r/mnt/stateful_partition/dev_image/etc/lsb-factory
+sudo umount r
+rmdir r
+sync
+pigz -9 rootfs
+mkimage -A x86 -O linux -T ramdisk -a 0x12008000 \
+	-n "Factory Install RootFS" -C gzip -d rootfs.gz \
+	initrd.uimg
+rm -f rootfs.gz