OpenWrt for NapiLab Napi family (RK3308)

Production-ready OpenWrt build for NapiLab Napi industrial IoT SBC and SOM based on Rockchip RK3308 SoC.

This repository contains all customizations needed to turn a vanilla OpenWrt snapshot into a fully functional industrial Modbus TCP gateway with a polished web interface.

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Supported hardware

Board	Storage	Docs
NapiLab Napi-C	4GB NAND — 32GB eMMC	Industrial SBC
NapiLab Napi-P	4GB NAND — 32GB eMMC	Industrial SBC
NapiLab Napi-Slot	4GB NAND — 32GB eMMC	SOM
Radxa ROCK Pi S	—	Community board, same RK3308 SoC

All boards share the same Rockchip RK3308 SoC — one firmware to rule them all.

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Using with other RK3308 boards

This build is not limited to NapiLab Napi boards. Any board based on Rockchip RK3308 can use the same customizations — just change the target profile in .config.

To build for a different board, replace the target device:

# List available RK3308 boards
grep "CONFIG_TARGET_rockchip_armv8_DEVICE" .config
 
# Example: build for Radxa ROCK Pi S
sed -i 's/CONFIG_TARGET_PROFILE="DEVICE_napilab_napic"/CONFIG_TARGET_PROFILE="DEVICE_radxa_rock-pi-s"/' .config

To switch to a different board, edit .config directly — never use make menuconfig as it will overwrite your configuration:

# Switch target profile to Radxa ROCK Pi S
sed -i 's/DEVICE_napilab_napic/DEVICE_radxa_rock-pi-s/g' .config

All uci-defaults scripts, packages and customizations will work on any RK3308 board. The only board-specific parts are:

• Device Tree (rk3308-napi-c.dts) — may need adjustment for different pin mux
• U-Boot defconfig (napic-rk3308) — based on ROCK Pi S, works on similar hardware
• MAC generation from OTP — works on all RK3308 boards

The same approach works for any OpenWrt-supported Rockchip board (RK3328, RK3566, RK3568, RK3588) — just select the appropriate target profile and adapt the DTS if needed.

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SoC features

Component	Details
SoC	Rockchip RK3308 (quad-core ARM Cortex-A35, 1.3GHz)
RAM	256MB / 512MB DDR3
Storage	4GB NAND up to 32GB eMMC
Ethernet	100Mbps (GMAC + RTL8201F PHY)
USB	2x USB 2.0 Host
UART	3x UART (ttyS0 console, ttyS1, ttyS2)
Wi-Fi	RTL8723DS (802.11b/g/n)

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What's inside

U-Boot

• Added napic-rk3308 U-Boot variant based on Radxa ROCK Pi S (same RK3308 hardware)
• Custom napic-rk3308_defconfig patch

Device Tree

• Custom DTS rk3308-napi-c.dts based on ROCK Pi S
• UART1 → /dev/ttyS1
• UART2 → /dev/ttyS2

Stable MAC address

Generated deterministically from RK3308 OTP data — same MAC across reboots on every board:

MAC=$(cat /sys/bus/nvmem/devices/rockchip-otp0/nvmem | md5sum | \
  sed 's/\(..\)\(..\)\(..\)\(..\)\(..\)\(..\).*/02:\1:\2:\3:\4:\5/')

First-boot configuration (uci-defaults)

Script	Purpose
70-rootpt-resize	Resize root partition to fill storage (reboot)
80-rootfs-resize	Expand filesystem after partition resize (reboot)
91-bash	Set bash as default shell for root
92-timezone	Set timezone to MSK-3
93-console-password	Enable password prompt on serial console
94-macaddr	Generate stable MAC from OTP
95-network	Configure eth0 without bridge
96-hostname	Set hostname to napiwrt
97-luci-theme	Set LuCI theme to openwrt-2020
99-dhcp	DHCP configuration

Pre-installed packages

Industrial stack

• mosquitto + mosquitto-client — MQTT broker
• mbusd + luci-app-mbusd — Modbus TCP gateway with web UI
• mbpoll — Modbus CLI tool

1-Wire / DS18B20

• owfs, owserver, owfs-client — 1-Wire bus support and device access

I2C / GPIO

• i2c-tools, libi2c — I2C bus diagnostics
• gpiod-tools, libgpiod — GPIO control via libgpiod

Metrics collection

• collectd + modules mqtt, exec, network, rrdtool, modbus — metrics collection and export

USB-Serial adapters

• kmod-usb-serial-ch341, cp210x, ftdi, pl2303

LTE modem

• kmod-usb-net-qmi-wwan + uqmi — Quectel EP06 support

Disk management and partition resize

• parted, fdisk, cfdisk, losetup, resize2fs

Networking and admin

• openssh-sftp-server — SFTP access
• luci-ssl-wolfssl — HTTPS for LuCI
• tcpdump, ethtool — network diagnostics
• bash, htop, nano, screen, tree — admin tools

C++ runtime

• libstdcpp — required for native Node.js modules (Zigbee2MQTT)

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luci-app-mbusd

Web interface for mbusd Modbus gateway — the crown jewel of this build.

• Start / Stop / Restart service
• Enable / Disable autostart
• Live process status with actual running parameters
• Listening IP:port display
• Full serial port and Modbus configuration

→ See luci-app-mbusd repository

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Building

Prerequisites (Ubuntu/Debian)

sudo apt install build-essential clang flex bison g++ gawk gcc-multilib \
  gettext git libncurses-dev libssl-dev python3-distutils rsync unzip zlib1g-dev

Setup

git clone https://github.com/openwrt/openwrt.git
cd openwrt
./scripts/feeds update -a
./scripts/feeds install -a

Apply customizations

tar xzf napic-openwrt-YYYYMMDD-HHMM-v1.0.tar.gz -C /path/to/openwrt/

Build U-Boot

make package/boot/uboot-rockchip/compile VARIANT=napic-rk3308 -j$(nproc)

Build image

make -j$(nproc)

Output: bin/targets/rockchip/armv8/openwrt-rockchip-armv8-napilab_napic-ext4-sysupgrade.img.gz

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Flashing

gunzip openwrt-rockchip-armv8-napilab_napic-ext4-sysupgrade.img.gz
dd if=openwrt-rockchip-armv8-napilab_napic-ext4-sysupgrade.img of=/dev/sdX bs=4M status=progress

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Default access

Parameter	Value
IP	DHCP (stable MAC ensures consistent lease)
Web UI	http://<IP>/ → LuCI
SSH	root@<IP>
Console	ttyS0, 1500000 baud

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Zigbee2MQTT

This build supports running Zigbee2MQTT on OpenWrt. Since OpenWrt uses musl libc, the standard Node.js binaries won't work — a special musl/aarch64 build is required.

A pre-built archive is available in Releases:

zigbee2mqtt-2.9.1-openwrt-aarch64-musl.tar.gz

Quick start

# Install Node.js (musl/arm64)
wget https://unofficial-builds.nodejs.org/download/release/v22.22.0/node-v22.22.0-linux-arm64-musl.tar.gz
mkdir -p /opt/node
tar xzf node-v22.22.0-linux-arm64-musl.tar.gz -C /opt/node --strip-components=1
 
# Install Zigbee2MQTT
mkdir /opt/zigbee2mqtt
tar xzf zigbee2mqtt-2.9.1-openwrt-aarch64-musl.tar.gz -C /opt/zigbee2mqtt/
 
# Install runtime dependency
apk add libstdcpp6
 
# Run
export PATH=/opt/node/bin:$PATH
cd /opt/zigbee2mqtt && npm start

Web UI available at http://<IP>:8080/

Requires 512 MB RAM and ~500 MB free disk space. Mosquitto is already pre-installed in this build.

Changelog

v1.0.2

• Zigbee2MQTT 2.9.1 pre-built archive for musl/aarch64 available in Releases
• Automatic root partition and filesystem resize on first boot (scripts 70/80-rootpt-resize, double reboot)
• Disk management: parted, fdisk, cfdisk, losetup, resize2fs
• 1-Wire / DS18B20: owfs, owserver, owfs-client — 1-Wire device support via OWFS
• I2C: i2c-tools, libi2c — I2C bus diagnostics and device access
• GPIO: gpiod-tools, libgpiod — GPIO control via libgpiod
• Collectd: collectd + modules mqtt, exec, network, rrdtool, modbus — metrics collection and export
• C++ runtime: libstdcpp — required for native Node.js modules (Zigbee2MQTT)
• Utilities: tree, fuse-utils

v1.0.1

• Automatic root partition resize on first boot (double reboot)
• Added packages: parted, fdisk, cfdisk, resize2fs, losetup

v1.0.0

• Initial release
• Custom U-Boot, DTS, uci-defaults
• mbusd + luci-app-mbusd
• Stable MAC from OTP

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License

GPL-2.0 (following OpenWrt)