Add howto, zephyr overlay and script to setup a static Thread network

Signed-off-by: Stefan Schmidt <stefan.schmidt@huawei.com>

README.md

@@ -20,3 +20,73 @@ flashing is the easiest option:
 ```
 $ west build -p auto -b arduino_nano_33_ble . && west flash
 ```
+
+
+## How to setup a static network setting between Linux and zephyr for development
+
+For development and testing purpose it might be useful to configure a static
+thread link between Linux and zephyr without the involvement of any
+commissioning process. This setup will use a networkkey that is hardcoded into
+the Zephyr firmware, which make this guide suitable for development purpose
+only. Do *not* use this in production.
+
+### Zephyr: building and flashing with static network config overlay
+
+When using the overlay-static.conf overlay file in the build the
+joiner/commissioner functionality is disabled and a static networkkey and
+setting configured.
+
+```
+$ west build -b arduino_nano_33_ble -- -DCONF_FILE="prj.conf overlay-static.conf" .
+$ west flash
+```
+
+### Linux: build and flash OT RCP on Zephyr onto Arduino Nano 33 BLE:
+
+On the Linux side we need 3 steps to setup.
+
+Build a OpenThread radio co-processor firmware for a second Arduino Nano (this
+one will act as a Thread radio for the Linux host). This is building a sample
+that lives within the main Zephyr tree.
+
+```
+$ west build -b arduino_nano_33_ble -- -DCONF_FILE="prj.conf overlay-rcp.conf overlay-usb-nrf-br.conf" -DDTC_OVERLAY_FILE="usb.overlay" -DCONFIG_OPENTHREAD_THREAD_VERSION_1_1=y samples/net/openthread/coprocessor/
+$ west flash
+```
+
+### Build and run ot-daemon:
+
+After flashing the ready we need to build the OpenThread daemon that runs on the
+Linux host and uses the radio to interact with a Thread network.
+When using the radio co-processor firmware on top of Zephyr we need to ensure that ot-daemon does handle USB reset properly. The compile flag -DOT_SPINEL_RESET_CONNECTION=ON, as well as, the runtime parameter &uart-reset is taking care of the reset handling.
+
+But there is still the underlying problem that during after a USB reset the
+/dev/ttyACM0 device will come back as /dev/ttyACM1 for example. So instead of
+using the ttyACMx device name we will use a serial/by-id lookup device name.
+When you first attach the Ardunio to the Linux host, after flashing the radio
+co-processor firmware, check the name in /dev/serial/by-id/ and not it down for
+later use. (It's the one that points to the current /dev/ttyACMx device and has
+Zephyr in its name). This device name will stay stable over USB reset so we no
+longer need to worry about device names changing underneath our daemon process.
+
+```
+git clone https://github.com/openthread/openthread.git
+cd openthread
+./bootstrap
+./script/cmake-build posix -DOT_SPINEL_RESET_CONNECTION=ON -DOT_THREAD_VERSION=1.1 -DOT_DAEMON=ON
+sudo build/posix/src/posix/ot-daemon -v 'spinel+hdlc+uart:///dev/serial/by-id/usb-ZEPHYR_OpenThread_CoProcessor_NRF_E96CD39E53C49869-if00?uart-baudrate=115200&uart-reset'
+```
+
+### Configure the static Thread network settings on Linux
+
+th the radio connected and ot-daemon running we can start the configuration
+script from another shell. It does use the ot-ctl commandline tool to configure
+the static Thread network to match the zephyr version.
+```
+sudo ./static-openthread-configuration.sh
+```
+
+The first device started should act as the Thread network leader and the second
+one joining as child and being promoted to a router over time. IPv6 connectivity
+between the two devices is working now and opens the floor for transport and
+application layer protocols to use it.

overlay-static.conf

+# This configuration uses a hardcoded network key and is not suitable for
+# usage besides debugging and development.
+
+# PAN ID 0x1357 to decimal 4951
+CONFIG_OPENTHREAD_PANID=4951
+CONFIG_OPENTHREAD_CHANNEL=26
+CONFIG_OPENTHREAD_NETWORK_NAME="OniroThread"
+CONFIG_OPENTHREAD_XPANID="0x11112222deadbeef"
+CONFIG_OPENTHREAD_NETWORKKEY="00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:ff"
+CONFIG_OPENTHREAD_JOINER=n
+CONFIG_OPENTHREAD_JOINER_AUTOSTART=n
+CONFIG_OPENTHREAD_JOINER_PSKD=""
+CONFIG_OPENTHREAD_SLAAC=y

static-openthread-configuration.sh

+#!/bin/sh
+# SPDX-FileCopyrightText: Huawei Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+set -e
+
+ot-ctl thread stop
+ot-ctl ifconfig down
+ot-ctl dataset clear
+ot-ctl dataset init new
+ot-ctl dataset panid 0x1357
+ot-ctl dataset extpanid 11112222deadbeef
+ot-ctl dataset networkname OniroThread
+ot-ctl dataset channel 26
+ot-ctl dataset networkkey 00112233445566778899aabbccddeeff
+ot-ctl dataset commit active
+ot-ctl ifconfig up
+ot-ctl thread start