NanoPi NEO4

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1 Introduction

Overview

Front

Back

• The NanoPi NEO4 is a RK3399 SoC based ARM board. Its PCB size is only 60 x 45 mm and has rich hardware resources. These features make it a good platform for rapid product prototyping and various applications.
• NanoPi NEO4 has 1GB RAM, an onboard 2.4G wireless module, and rich hardware resources, such as USB3.0, USB2.0, PCIe, GbE, HDMI, MIPI-CSI, eMMC socket, SPI, GPIO, I2C, PWM, RTC, UART, etc.
• NanoPi NEO4 can be booted from either a TF card or an external eMMC module.
• The NanoPi NEO4 supports Ubuntu Desktop 18.04(64-bit), Lubuntu 16.04(32-bit), Ubuntu Core 18.04(64-bit) and Lubuntu Desktop with GPU and VPU acceleration. With these rich resources and powerful performance it can be widely used in applications of machine learning, AI, deep learning, robots, industrial control, industrial cameras, advertisement machines, game machines, blockchain and etc.

2 Hardware Spec

• SoC: Rockchip RK3399
  • CPU: big.LITTLE，Dual-Core Cortex-A72(up to 2.0GHz) + Quad-Core Cortex-A53(up to 1.5GHz)
  • GPU: Mali-T864 GPU，supports OpenGL ES1.1/2.0/3.0/3.1, OpenVG1.1, OpenCL, DX11, and AFBC
  • VPU: 4K VP9 and 4K 10bits H265/H264 60fps decoding, Dual VOP, etc
• PMU: RK808-D PMIC, cooperated with independent DC/DC, enabling DVFS, solfware power-down, RTC wake-up, system sleep mode
• RAM: 1GB DDR3-1866
• Flash: no Onboard eMMC, but has a eMMC socket
• Ethernet: Native Gigabit Ethernet
• Wi-Fi/BT: 802.11 b/g/n, Bluetooth 4.0 combo module
• Video Input: one 4-Lane MIPI-CSI, up to 13MP
• Video output: HDMI: HDMI 2.0a, supports 4K@60Hz，HDCP 1.4/2.2
• Audio Out: HDMI
• USB 3.0: 1x USB 3.0 Host Type-A
• USB 2.0: 2x USB 2.0 Host, one is Type-A, the other is 2.54mm header
• USB Type-C: Supports USB2.0 OTG and Power input
• microSD Slot x 1
• GPIO1, 40Pin GPIO:
  • 2 X 3V I2C, 1x 3V UART/SPI, 1 x SPDIF_TX, up to 8 x 3V GPIOs
  • PCIe x2
  • PWM x1, PowerKey
• GPIO2：
  • 1 x 1.8V 8ch-I2S
• GPIO3：
  • debug uart, 3V level, 1500000bps
  • USB 2.0 x1
• LED: 1 x power LED and 1 x GPIO Controled LED
• RTC Battery: 2 Pin 2.54mm pitch through-hole pads
• Power supply: 5V/3A
• PCB: 8 Layer, 60 mm x 45 mm
• Ambient Operating Temperature: -20℃ to 70℃

3 Diagram, Layout and Dimension

3.1 Layout

NanoPi NEO4 Layout

• GPIO1，40-Pin Spec

Pin#	Assignment	Pin#	Assignment
1	VCC3V3_SYS	2	VDD_5V
3	I2C2_SDA(3V)	4	VDD_5V
5	I2C2_SCL(3V)	6	GND
7	GPIO1_A0(3V)	8	GPIO4_C1/I2C3_SCL(3V)
9	GND	10	GPIO4_C0/I2C3_SDA(3V)
11	GPIO1_A1(3V)	12	GPIO1_C2(3V)
13	GPIO1_A3(3V)	14	GND
15	GPIO1_A4(3V)	16	GPIO1_C6(3V)
17	VCC3V3_SYS	18	GPIO1_C7(3V)
19	SPI1_TXD/UARNEO4_TX(3V)	20	GND
21	SPI1_RXD/UARNEO4_RX(3V)	22	GPIO1_D0(3V)
23	SPI1_CLK(3V)	24	SPI1_CSn0(3V)
25	GND	26	GPIO4_C5/SPDIF_TX(3V)
27	PCIE_REF_CLKP	28	GPIO4_C6/PWM1(3V)
29	PCIE_REF_CLKN	30	PWR_KEY
31	GND	32	GND
33	PCIE_TX0P	34	PCIE_TX1P
35	PCIE_TX0N	36	PCIE_TX1N
37	PCIE_RX0_P	38	PCIE_RX1_P
39	PCIE_RX0_N	40	PCIE_RX1_N

• GPIO2，8-Pin I2S Spec

I2S signals is 1.8V level

Pin#	Assignment	Pin#	Assignment
1	GND	2	I2S0_SDI0
3	VCC5V0_SYS	4	I2S0_SDI1SDO3
5	I2S0_LRCK_RX	6	I2S0_SDI2SDO2
7	I2S0_SCLK	8	I2S0_SDI3SDO1

• GPIO3，8-Pin UART/USB Spec

debug uart is 3V level, 1500000bps

Pin#	Assignment	Description	Pin#	Assignment	Description
1	UART2DBG_RX	debug uart intput	2	VCC5V0_SYS	5V power output
3	UART2DBG_TX	debug uart output	4	HOST1_DM	USB 2.0 data -
5	VCC5V0_SYS	5V power output	6	HOST1_DP	USB 2.0 data +
7	GND	0V	8	GND	0V

• MIPI-CSI Interface Pin Spec

0.5mm FPC Connector

Pin#	MIPI-CSI1	Description
1	VCC5V0_SYS	5V Power ouput
2	VCC5V0_SYS	5V Power ouput
3	GND	Return current path
4	VCC_CSI_AF2.8V	2.8V Power for VCM
5	VCC_CSI_1.2V	1.2V Power for image sensor core circuit
6	VCC1V8_CAM	1.8V power for I/O circuit
7	VCC_CSI_2.8V	2.8V power for image sensor analog circuit
8	VCC_CSI_1.0V	1.0V Power for image sensor core circuit
9	I2C1_SCL	1.8V I2C clock signal
10	I2C1_SDA	1.8V I2C data signal
11	MIPI_CSI0_RST	reset camera module
12	MIPI_CSI0_PWN	Power down camera module
13	GND	Return current path
14	GPIO2_B3_CIF_CLKOUTA	MCLK to camera module
15	GND	Return current path
16	MIPI_RX0_D3P	MIPI CSI positive differential data line transceiver output
17	MIPI_RX0_D3N	MIPI CSI negative differential data line transceiver output
18	GND	Return current path
19	MIPI_RX0_D2P	MIPI CSI positive differential data line transceiver output
20	MIPI_RX0_D2N	MIPI CSI negative differential data line transceiver output
21	GND	Return current path
22	MIPI_RX0_D1P	MIPI CSI positive differential data line transceiver output
23	MIPI_RX0_D1N	MIPI CSI negative differential data line transceiver output
24	GND	Return current path
25	MIPI_RX0_CLKP	MIPI CSI positive differential clock line transceiver output
26	MIPI_RX0_CLKN	MIPI CSI negative differential clock line transceiver output
27	GND	Return current path
28	MIPI_RX0_D0P	MIPI CSI positive differential data line transceiver output
29	MIPI_RX0_D0N	MIPI CSI negative differential data line transceiver output
30	GND	Return current path

• eMMC Socket Pin Spec

Pin#	Assignment	Pin#	Assignment
1	EMMC_D0	2	EMMC_D1
3	EMMC_D2	4	EMMC_D3
5	EMMC_D4	6	EMMC_D5
7	EMMC_D6	8	EMMC_D7
9	EMMC_STRB	10	GND
11	EMMC_CMD	12	EMMC_CLKO
13	N/C	14	GND
15	N/C	16	VCC1V8_S3
17	eMMC_RST	18	VCC3V3_S3
19	GND	20	GND

• USB Port

USB Type-A has 2A overcurrent protection.

• RTC

RTC backup current is 27uA.

Notes

1. Power Input : 5V/3A, via USB Type-C or Pin2&Pin4 of the 40-pin GPIO1 header
2. For more details refer to the Schematic: NanoPi-NEO4-1808-Schematic.pdf

3.2 Board Dimension

For more details refer to the CAD document: NanoPi-NEO4-1808-Drawing(dxf).zip

4 Get Started

4.1 Essentials You Need

Before starting to use your NanoPi-NEO4 get the following items ready

• NanoPi-NEO4
• Type-C cable
• TF Card: Class 10 or Above, minimum 8GB SDHC
• USB to serial adapter(optinal, for debugging or access from PC host)
• 5V/3A Power adapter
• HDMI monitor or LCD
• USB keyboard, mouse and possible a USB hub(or a TTL to serial board)
• A host computer running Ubuntu 18.04 64-bit system

4.2 Boot from SD Card

Get the following files from here download link:

• Get an 8G SDHC card and backup its data if necessary.
  

Image Files
rk3399-sd-debian-bullseye-core-4.19-arm64-YYYYMMDD.img.gz	Debian 11(Bullseye) Core, No desktop environment, command line only, Kernel version 4.19.y
rk3399-sd-debian-buster-desktop-arm64-YYYYMMDD.img.gz	Debian 10(buster) Desktop, Uses LXDE as default desktop, Supports hardware acceleration, Kernel version 4.19.y
rk3399-sd-buildroot-linux-4.19-arm64-YYYYMMDD.img.zip	Buildroot image file with Qt5-wayland (base on Rockchip Linux SDK)
rk3399-sd-friendlydesktop-bionic-4.4-arm64-YYYYMMDD.img.zip	FriendlyDesktop image file with X Window (base on Ubuntu 18.04 64bit)
rk3399-sd-friendlycore-bionic-4.4-arm64-YYYYMMDD.img.gz	FriendlyCore with Qt 5.10.0 (base on Ubuntu core 18.04) image file, kernel 4.4
rk3399-sd-friendlycore-focal-4.19-arm64-YYYYMMDD.img.gz	FriendlyCore with Qt 5.10.0 (base on Ubuntu core 20.04) image file, kernel 4.19
rk3399-sd-friendlycore-lite-focal-5.15-arm64-YYYYMMDD.img.gz	Lite version, No pre-installed Qt, Base on Ubuntu core 20.04, kernel 5.15
rk3399-sd-lubuntu-desktop-xenial-4.4-armhf-YYYYMMDD.img.zip	Lubuntu Desktop image file with X Window
rk3399-sd-android10-YYYYMMDD.img.gz	Android 10
rk3399-sd-friendlywrt-YYYYMMDD.img.zip	FriendlyWrt image file, based on OpenWrt 21.02, kernel version 5.15.y
rk3399-sd-friendlywrt-21.02-docker-YYYYMMDD.img.gz	FriendlyWrt image file，based on OpenWrt 21.02, Pre-installed Docker，kernel version 5.15.y
rk3399-sd-friendlywrt-22.03-YYYYMMDD.img.gz	FriendlyWrt image file，based on OpenWrt 22.03，kernel version 5.15.y
rk3399-sd-friendlywrt-22.03-docker-YYYYMMDD.img.gz	FriendlyWrt image file，based on OpenWrt 22.03, Pre-installed Docker，kernel version 5.15.y
rk3399-sd-friendlywrt-kernel4-YYYYMMDD.img.zip	FriendlyWrt image file, based on OpenWrt 21.02, kernel version 4.19.y
Flash Utility:
win32diskimager.rar	Windows utility. Under Linux users can use "dd"

• Extract these files. Insert an SD card(at least 8G) into a Windows PC and run the win32diskimager utility as administrator. On the utility's main window select your SD card's drive, the wanted image file and click on "write" to start flashing the SD card.
• Insert this card into your board's boot slot and power on, If the PWR LED is on and LED1 is blinking this indicates your board has successfully booted.
• The Android system does not support starting from the SD card. If you need to run the Android system, please buy the eMMC module, and then burn the Android system to the eMMC to run, referring to the following section.

5 Access hardware

5.1 Access Serial Interface

For now only UART4 is available for users:

Serial Interface	Serial Device
UART0	Used by Bluetooth
UART1	Used by Gbps Ethernet
UART2	Used by Serial Debug Port
UART3	Used by Gbps Ethernet
UART4	Available, device name is /dev/ttyS4 (note: this is only applicable for ROM released after 20180618)

6 Work with FriendlyDesktop

Arduino

Firefox

Scratch

FriendlyDesktop is a light-weighted Ubuntu desktop system. It is based on LXDE and has the following features:
    Latest Version － Based on Ubuntu 18.04 64
    Various Development Utilities － It is compatible with FriendlyCore and has integrated an optimized Qt5.10, QtCreator and Arduino IDE.
    Light-weighted － it consumes relatively less CPU resources than a common desktop system. When a system's RAM is sufficient it can achieve much better performance.
    Less Power Consumption － it consumes relatively less power or resources than a common desktop system to achieve the same performance.
    Compact and Neat － its desktop is based on GTK+ 2 and it supports multiple languages.
    Easy to Use － its GUI looks similar to MS Windows'.
    Customizable － Users can customize LXDE's GUI.
    Compatible － it is compatible with freedesktop.org.
FriendlyELEC has optimized support for Mali GPU and VPU in FriendlyDesktop for RK3399 and integrated drivers for X.org. FriendlyDesktop supports Hardware Cursor, OpenGL graphic acceleration, 4K video playing with hardware decoding.

6.1 Account & Password

Regular Account:

   User Name: pi
   Password: pi

Root:

   User Name: root
   Password: fa

6.2 WiFi Connection

Click on the icon on the top right in the FriendlyDesktop's main window, select your wanted WiFi hotspot and proceed with prompts

6.3 HDMI/DP LCD Resolution

Open the system's menu and go to Perferences -> Monitor Settings to customize your settings.
Recommended resolution: 1920x1080@60Hz

6.4 Adjust HDMI overscan

Open the command line terminal and enter the command to operate, Note:
1) You need to login to the desktop;
2) If you are using ssh terminal, please use the same username as the desktop login. The default is pi. You cannot use the root user. you also need to assign the DISPLAY variable:

export DISPLAY=:0.0

6.4.1 Query which resolutions the display supports

xrandr -q

6.4.2 Set resolution

For example set to 1920X1080@60Hz:

xrandr --output HDMI-1 --mode 1920x1080 --refresh 60

6.4.3 Adjust the HDMI overscan

For example, the transformation scaling horizontal coordinates by 0.8, vertical coordinates by 1.04 and moving the screen by 35 pixels right and 19 pixels down:

xrandr --output HDMI-1 --transform 0.80,0,-35,0,1.04,-19,0,0,1

6.4.4 Automatic adjustment at boot

Edit ~/.config/autostart/lxrandr-autostart.desktop，Write the full xrandr command to the key at the beginning of "Exec= as shown below：

[Desktop Entry]
Type=Application
Name=LXRandR autostart
Comment=Start xrandr with settings done in LXRandR
Exec=sh -c 'xrandr --output HDMI-1 --mode 1920x1080 --refresh 50 --transform 1.04,0,-35,0,1.05,-30,0,0,1'
OnlyShowIn=LXDE

6.5 eDP LCD Display Rotation

If you want to rotate an eDP LCD's display you can do it by commanding "xrotate.sh" to rotate its display to 90/180/270 degrees. You can rotate display clockwise by 90 degrees by running the following command as root. This command calls lightdm to make your change effective immediately:

sudo xrotate.sh -m CW -r

For more details about its options you can run "xrotate -h".
Note: this command doesn't support HDMI display's rotation. If you want to rorate an HDMI's display you need to refer to X11's tech documents and make changes in "/etc/X11/xorg.conf".

Note: when you play a video with hardware decoding your player's display window doesn't rotate with your LCD's display

6.6 Test OpenGL ES

You can test it by clicking on the Terminator icon to start a commandline utility in the System Tools and run the following commands:

taskset -c 4-5 glmark2-es2

6.7 4K Video Playing

6.7.1 Play with Qt Player with Hardware Decoding

FriendlyDesktop has integrated a Qt5-VideoPlayer utility. This utility has support for Rockchip's gstreamer plug-in and supports 4K video playing with hardware decoding. You can start it by following the steps below: On FriendlyDesktop's main window open "Sound & Video" and click on "Qt5-VideoPlayer".

On the player's main window click on the bottom left's "Open" button to load a video file and double-click on its name on the file list to start video playing. Here is how it looks like. You can set the display window to full screen and adjust the volume:

Qt5-VideoPlayer source code: https://github.com/friendlyarm/rk-player-qt

6.7.2 Play with Linux Command

You can play it by running the following command in a commandline utility:

gst-player.sh

By default its voice will be output to audio jack. You can locate this script by commanding "which gst-player.sh". You can customize its behavior by making changes in this script.

6.8 Work with USB Camera

Insert the USB camera (such as Logitech C270/C920) into the development board. Double click the "USB Camera" icon on desktop will pop up the luvcview gui (need to use the 2019/05/11+ version firmware).
the luvcview tool is an open source software that you can compile yourself:

git clone https://github.com/ksv1986/luvcview
cd luvcview
make

View the usage of luvcview:

./luvcview -h

Parameter Description:

luvcview version 0.2.1
Usage: uvcview [-h -d -g -f -s -i -c -o -C -S -L -l -r]
-h print this message
-d /dev/videoX use videoX device
-g use read method for grab instead mmap
-w disable SDL hardware accel.
-f video format default jpg others options are yuv jpg
-i fps use specified frame interval
-s widthxheight use specified input size
-c enable raw frame capturing for the first frame
-C enable raw frame stream capturing from the start
-S enable raw stream capturing from the start
-o avifile create avifile, default video.avi
-L query valid video formats
-l query valid controls and settings
-r read and set control settings from luvcview.cfg

To preview USB camera (640x360@30fps), you can use the following command:

./luvcview -d /dev/video8 -i 30 -s 640x360

As you can see from the output of luvcview, hardware acceleration has been turned on:

pi@NanoPC-T4:/etc/xrdp$ luvcview -d /dev/video8 -i 30 -s 640x360
luvcview version 0.2.1
 interval: 30 fps
Hardware acceleration available
video /dev/video8

6.9 File Transfer with Bluetooth

Click on the "Preferences" in the main window's menu to start Bluetooth Manager and click on "Search" to search surrounding Bluetooth devices. Click on your wanted device, pair the device with your board and you will be able to do file transfer, here is how it looks like:

6.10 Install OpenCV

OpenCV has been pre-installed in FriendlyCore/FriendlyDesktop (Version after 201905) and does not require manual installation.
Please refre this link: https://github.com/friendlyarm/install-opencv-on-friendlycore/blob/rk3399/README.md

6.11 Develop Qt Applications

FriendlyDesktop has a Qt 5.10.0 which supports RK3399's OpenGL ES and Gstreamer 1.0 hardware acceleration and a QtCreator IDE which is ready and can be used to compile and run applications. Here is how it looks like:

When running the Qt app, you need to specify the platform parameter to xcb as follows:

./HelloQt --platform xcb

6.12 WiringPi and Python Wrapper

• WiringPi for RK3399
• WiringPi-Python for RK3399

6.13 Switch audio default output device

6.13.1 View the current default output device

On the terminal of the non-root user, enter the following command:

pactl info -vvv

The information displayed contains the following, indicating that the current audio output is directed to the headset:

Default Sink: alsa_output.platform-rt5651-sound.stereo-fallback

The information displayed contains the following, indicating that the current audio output is to HDMI:

Default Sink: alsa_output.platform-hdmi-sound.stereo-fallback

6.13.2 Set headphone jack as the default output device

On the terminal of the non-root user, enter the following command:

pactl set-default-sink  alsa_output.platform-rt5651-sound.stereo-fallback

Set default volume to 20%:

pactl -- set-sink-volume alsa_output.platform-rt5651-sound.stereo-fallback 20%

6.13.3 Set hdmi as the default output device

On the terminal of the non-root user, enter the following command:

pactl set-default-sink  alsa_output.platform-hdmi-sound.stereo-fallback

6.13.4 View settings have taken effect

cat /var/lib/pulse/*-default-sink

6.13.5 Temporary switching during playback

This method is only valid for the current playback process:
Open the menu "Sound & Video" -> "PulseAudio Volume Control", click the "Built-in Audio Stereo" button on the interface to switch between different output devices, such as switching between HDMI and headphone jack.

6.14 Play RTSP video stream (or IP Camera)

Open a command line terminal and enter the following command:

gst-launch-1.0 rtspsrc location="rtsp://admin:12345@192.168.1.120:554/live/main" ! rtph264depay ! decodebin ! rkximagesink

Change the address after rtsp:// to the real address.

6.15 Chromium web browser

Chromium web browser has enabled hardware acceleration by default, supports WebGL, and can view hardware acceleration details by entering the URL chrome://gpu, as shown below:

6.16 Screen saver and auto sleep related settings

The screen saver configuration file is /etc/xdg/autostart/xset_command.desktop. The default factory settings are that the screen saver and DPMS are both closed. You can change the configuration by modifying this file.

6.17 Install Scratch

enter the following command:

sudo apt-get install scratch:arm64

6.18 Install Arduino IDE

enter the following command:

sudo apt-get install arduino:arm64

6.19 Start the program automatically at startup

Put the desktop file in the ~/.config/autostart/ directory, for example：

cp /usr/share/applications/org.qt-project.qtcreator.desktop ~/.config/autostart/

6.20 Login to the desktop as the root user

Edit the /root/.profile file：

sudo vim /root/.profile

Replace with the following:

if [ -n "$BASH_VERSION" ]; then
    if [ -f "$HOME/.bashrc" ]; then
	. "$HOME/.bashrc"
    fi
fi
if [ -d "$HOME/bin" ] ; then
    PATH="$HOME/bin:$PATH"
fi

Run the following command to modify the lightdm configuration file and change the automatically logged-in user name to root:

sudo sed -i 's/autologin-user=pi/autologin-user=root/g' /usr/share/lightdm/lightdm.conf.d/20-defaultsession.conf

Run the reboot command to restart:

sudo reboot

If you want to log in, the desktop icons and configuration are the same as the pi user, you can copy the relevant directory from the /home/pi directory:

sudo rm -rf /root/Desktop /root/Pictures /root/.config
sudo cp -af /home/pi/Desktop /home/pi/Pictures /home/pi/.config /root/
sudo chown root:root /root/Desktop /root/Pictures /root/.config

7 Work with FriendlyCore

7.1 Introduction

FriendlyCore is a Ubuntu core based OS which doesn't have X Desktop. Its current version is 18.04

FriendlyCore targets enterprise users and is customized for industrial applications. FriendlyCore and Ubuntu base target different users. FriendlyCore has both a commandline utility and a two GUI utilities:
1）Qt 5.10.0 cuustomized for ROCKCHIP3399. It supports GPU and VPU acceleration and has modules like: QtQuick/QtWebEngine/QtMultimedia/WebGL and three display plug-ins:KMS, EGLFS and XCB;
2) Xorg system. It can run X11 applications and supports hardware acceleration;

FriendlyCore for RK3399 has the following features:

• supports FriendlyElec's 7"LCD with capacitive touch - HD702. If a board is connected to both an LCD and an HDMI monitor the LCD and the HDMI monitor can be set to display either differently or the same;
• supports Gstreamer 1.0 multi-media framework;
• supports hard encoding video playing with either commandline utility or Qt player;
• supports Qt5 WebGL;
• supports Qt5 VNC and runs a Qt application as a VNC Server allowing remote control;
• supports bluetooth. It has preinstalled bluez packages;

7.2 System Login

• If your board is connected to an HDMI monitor you need to use a USB mouse and keyboard.
• If you want to do kernel development you need to use a serial communication board, ie a PSU-ONECOM board, which will

You can use a USB to Serial on NanoPi-NEO4：

• FriendlyCore User Accounts:

Non-root User:

   User Name: pi
   Password: pi

Root:

   User Name: root
   Password: fa

The system is automatically logged in as "pi". You can do "sudo npi-config" to disable auto login.

• Update packages

$ sudo apt-get update

7.3 Configure System with npi-config

The npi-config is a commandline utility which can be used to initialize system configurations such as user password, system language, time zone, Hostname, SSH switch , Auto login and etc. Type the following command to run this utility.

$ sudo npi-config

Here is how npi-config's GUI looks like:

7.4 Develop Qt Application

The Qt 5.10.0 FriendlyELEC ported for RK3399 supports the following plug-ins:KMS, EGLFS and XCB. All these three plug-ins support OpenGL ES and GPU hardware acceleration but in different ways:

• KMS - it calls Linux kernel's DRM interface to display
  
• EGLFS - it calls OpenGL ES interface to display
  
• XCB - it runs on X11 server and is integrated in X11 windows system
  

Three plug-ins support different Qt features and here is a table:

Plug-in	OpenGL ES	QtWebEngine	QtMultimedia	Video Playing with Hardware Decoding	Different Display
KMS	Yes	No	Yes	No	Yes
EGLFS	Yes	No	Yes	No	No
XCB	Yes	Yes	Yes	Yes	Yes

We recommend to use KMS or XCB.

FriendlyCore has four scripts for setting Qt environmental variables for users and here is a table:

Script	Comment
/usr/bin/setqt5env-kms	set kms' environmental variables
/usr/bin/setqt5env-eglfs	set eglfs' environmental variables
/usr/bin/setqt5env-xcb	set xcb's environmental variables
/usr/bin/setqt5env-nogui	set environmental variables for a system without a Qt GUI

For instance, if you want to use KMS to display you can run the following commands:

. setqt5env-kms
./apps

(Note:there is a space between '.' and 's')

7.4.1 Setup Qt Development Envronment

FriendlyELEC developed two methods for RK3399 to cross-compile a Qt program:

• 1:Use Docker. For more details you can refer to github :http://github.com/friendlyarm/friendlyelec-ubuntu18-docker
• 2:Setup a local cross-compiler. You need to run a Ubuntu 18.04 64-bit OS and you can refer to :How to Build and Install Qt Application for FriendlyELEC Boards/zh

7.4.2 Qt Demo

FriendlyCore has several Qt demo programs:

• Qt QML: CinematicExperience

CinematicExperience is a utility for selecting a video file and it is developed with Qt QML.
This demo uses Qt QML's various features and runs very smoothly on RK3399. This performance is achieved by hardware and software optimization.
You can start it in a commandline utility by running the following commands:

cd /opt/Qt5_CinematicExperience
./run.sh

Here is what it looks like:

• QQt WebEngine: web browser

Qt WebEngine uses Chromium and supports HTML5.
You can start it by running the following commands:

cd /opt/qt5-brower
./run.sh

Here is what it looks like:

Note:Qt WebEngine depends on the Xcb plug-in.

• Qt Different Display

This demo shows that when a board is connected to an HDMI monitor and an eDP LCD these two devices display differently. You can start it by running the following commands:

cd /opt/qt5-multi-screen-demo
./run.sh

Here is what it looks like:

• Qt Multimedia: qt5-player with hard decoding

The qt5-player works with Rockchip's gstreamer plug-in and supports 4K video playing. Since Rockchip's plug-in only supports output images to an X11 window the qt5-player needs to use XCB for display.
You can start the demo by running the following commands:

cd /opt/qt5-player
./run.sh

Here is what it looks like. You can set it to display in full-screen and adjust the voice's volume:

• Qt WebGL demo: nmapper

Qt WebGL allows you to remotely access a Qt program running on your board.
Before you run the demo you need to connect your board to the internet and run the following commands:

cd /opt/qt5-nmapper
./run-with-webgl.sh

You can open a browser on another device, type the IP address of your board on the browser's address bar, enter and you will be able to see a Qt GUI. Here is what it looks like:

• Qt VNC demo: Smart home applicance GUI

Qt VNC allows you to run a program as a VNC Server on your board and you can access the program from a VNC client on another device. This program can be developed with either QtWidgets or QML.
You can start it by running the following commands:

cd /opt/qt5-smarthome
./run-with-vnc.sh

Start a VNC viewer on a smart phone or mobile device and type your board's IP address and port number 5900. For instance if your board's IP address is 192.168.1.100 you can type "192.168.1.100:5900", enter and you will see the following GUI:

7.4.3 Play with Dual Cameras under Qt

This sample shows how to connect dual cameras to the board and play with them. Before run the sample make sure you connect dual cameras and an LCD to your board. In general popular UVC cameras should work however we suggest users use the following modules which we have tested:

Index	Model
1	Logitech C270
2	Logitech C270i
3	Logitech C922 Pro

Run the following commands:

cd /opt/dual-camera
./run.sh

Here is what you expect to observe:

7.5 Setup Program to AutoRun

You can setup a program to autorun on system boot with npi-config:

sudo npi-config

Go to Boot Options -> Autologin -> Qt/Embedded, select Enable and reboot.

7.6 Extend TF Card's Section

When FriendlyCore is loaded the TF card's section will be automatically extended.You can check the section's size by running the following command:

$ df -h

7.7 Transfer files using Bluetooth

Take the example of transferring files to the mobile phone. First, set your mobile phone Bluetooth to detectable status, then execute the following command to start Bluetooth search.：

hcitool scan

Search results look like：

Scanning ...
    2C:8A:72:1D:46:02   HTC6525LVW

This means that a mobile phone named HTC6525LVW is searched. We write down the MAC address in front of the phone name, and then use the sdptool command to view the Bluetooth service supported by the phone：

sdptool browser 2C:8A:72:1D:46:02

Note: Please replace the MAC address in the above command with the actual Bluetooth MAC address of the mobile phone.
This command will detail the protocols supported by Bluetooth for mobile phones. What we need to care about is a file transfer service called OBEX Object Push. Take the HTC6525LVW mobile phone as an example. The results are as follows：

Service Name: OBEX Object Push
Service RecHandle: 0x1000b
Service Class ID List:
  "OBEX Object Push" (0x1105)
Protocol Descriptor List:
  "L2CAP" (0x0100)
  "RFCOMM" (0x0003)
    Channel: 12
  "OBEX" (0x0008)
Profile Descriptor List:
  "OBEX Object Push" (0x1105)
    Version: 0x0100

As can be seen from the above information, the channel used by the OBEX Object Push service of this mobile phone is 12, we need to pass it to the obexftp command, and finally the command to initiate the file transfer request is as follows：

obexftp --nopath --noconn --uuid none --bluetooth -b 2C:8A:72:1D:46:02 -B 12 -put example.jpg

Note: Please replace the MAC address, channel and file name in the above command with the actual one.

After executing the above commands, please pay attention to the screen of the mobile phone. The mobile phone will pop up a prompt for pairing and receiving files. After confirming, the file transfer will start.

Bluetooth FAQ：
1) Bluetooth device not found on the development board, try to open Bluetooth with the following command：

rfkill unblock 0

2) Prompt can not find the relevant command, you can try to install related software with the following command：

apt-get install bluetooth bluez obexftp openobex-apps python-gobject ussp-push

7.8 WiFi

For either an SD WiFi or a USB WiFi you can connect it to your board in the same way. The APXX series WiFi chips are SD WiFi chips. By default FriendlyElec's system supports most popular USB WiFi modules. Here is a list of the USB WiFi modules we tested:

Index	Model
1	RTL8188CUS/8188EU 802.11n WLAN Adapter
2	RT2070 Wireless Adapter
3	RT2870/RT3070 Wireless Adapter
4	RTL8192CU Wireless Adapter
5	mi WiFi mt7601
6	5G USB WiFi RTL8821CU
7	5G USB WiFi RTL8812AU

You can use the NetworkManager utility to manage network. You can run "nmcli" in the commandline utility to start it. Here are the commands to start a WiFi connection:

• Change to root

$ su root

• Check device list

$ nmcli dev

Note: if the status of a device is "unmanaged" it means that device cannot be accessed by NetworkManager. To make it accessed you need to clear the settings under "/etc/network/interfaces" and reboot your system.

• Start WiFi

$ nmcli r wifi on

• Scan Surrounding WiFi Sources

$ nmcli dev wifi

• Connect to a WiFi Source

$ nmcli dev wifi connect "SSID" password "PASSWORD" ifname wlan0

The "SSID" and "PASSWORD" need to be replaced with your actual SSID and password.If you have multiple WiFi devices you need to specify the one you want to connect to a WiFi source with iface
If a connection succeeds it will be automatically setup on next system reboot.

For more details about NetworkManager refer to this link: Use NetworkManager to configure network settings

If your USB WiFi module doesn't work most likely your system doesn't have its driver. For a Debian system you can get a driver from Debian-WiFi and install it on your system. For a Ubuntu system you can install a driver by running the following commands:

$ apt-get install linux-firmware

In general all WiFi drivers are located at the "/lib/firmware" directory.

7.9 Ethernet Connection

If a board is connected to a network via Ethernet before it is powered on it will automatically obtain an IP with DHCP activated after it is powered up. If you want to set up a static IP refer to: Use NetworkManager to configure network settings。

7.10 WiringPi and Python Wrapper

• WiringPi for RK3399
• WiringPi-Python for RK3399

7.11 Custom welcome message

The welcome message is printed from the script in this directory：

/etc/update-motd.d/

For example, to change the FriendlyELEC LOGO, you can change the file /etc/update-motd.d/10-header. For example, to change the LOGO to HELLO, you can change the following line：

TERM=linux toilet -f standard -F metal $BOARD_VENDOR

To:

TERM=linux toilet -f standard -F metal HELLO

7.12 Modify timezone

For exampe, change to Shanghai timezone:

sudo rm /etc/localtime
sudo ln -ls /usr/share/zoneinfo/Asia/Shanghai /etc/localtime

7.13 Select the system default audio device

You can set the system default audio device by following the steps below.
Use the following command to view all the sound card devices in the system (Note: different development boards will have different results):

pi@NanoPi:~$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: realtekrt5651co [realtek,rt5651-codec], device 0: ff880000.i2s-rt5651-aif1 rt5651-aif1-0 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: rockchiphdmi [rockchip,hdmi], device 0: ff8a0000.i2s-i2s-hifi i2s-hifi-0 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: ROCKCHIPSPDIF [ROCKCHIP,SPDIF], device 0: ff870000.spdif-dit-hifi dit-hifi-0 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0

As you can see, the following sound card devices are available on the hardware:

Sound card device	Sound card number	Description
realtekrt5651co	0	Realtek sound card's default output interface (through 3.5mm jack interface)
rockchiphdmi	1	HDMI
ROCKCHIPSPDIF	2	SPDIF (Note: temporarily unavailable, because the hardware is not exported)...

To configure the audio output to the 3.5mm jack, modify the configuration file /etc/asound.conf and modify it to the following:

defaults.pcm.card 0
defaults.pcm.device 0

To configure to output audio to HDMI, change the defaults.pcm.card above to 1.
Note that some boards do not have a Realtek sound card (no 3.5mm jack interface), so the card number of the HDMI device will be 0, so the configuration should be based on the result of the aplay -l command.

7.14 Run the X11 application

FriendlyCore system built-in lightweight Xorg，although there is no window manager, you can still run a single X-Windows application，For example, the program to run is ~/YourX11App，use the following command：

. /usr/bin/setqt5env-xcb
startx ~/YourX11App -geometry 1280x800

Note that there is a space between "." and /usr/bin/setqt5env-xcb. In addition, the resolution after -geometry should be changed to the actual resolution of your screen.

7.15 Mpv hardware decoding video player

FriendlyCore comes pre-installed with the ffmpeg-based command line video player mpv, which also includes libmpv.
The mpv player supports Rockchip MPP video decoder, so it supports 4K hardware decoding. There are many parameters of mpv. In order to simplify the use, we provide a script start-mpv. After simplification, there is only one parameter: video file name, as follows:

start-mpv /home/pi/demo.mp4

It should be noted that the pi user needs to log in during playback, because there are no mpv related settings in other users' directories. Of course, you can copy one from the pi user directory. The mpv settings file is stored in the following path：

/home/pi/.config/mpv/mpv.conf

The contents of the mpv.conf file are as follows：

vo=gpu
gpu-context=drm
hwdec=rkmpp
demuxer-max-bytes=41943040
demuxer-max-back-bytes=41943040
drm-osd-plane-id=1
drm-video-plane-id=0
audio-device=alsa/default:CARD=rockchiphdmi

These will be passed as parameters to mpv. When the value of hwdec is rkmpp, it means using hardware decoding, audio-device is used to specify the audio output device, and the default output is to HDMI. You can use the following command to query which audio devices are in the system：

mpv --audio-device=help

Another important parameter is drm-osd-size. When playing video in full screen, drm-osd-size is specified as the resolution of the screen. This parameter is automatically obtained by start-mpv and passed to mpv, start-mpv script will do one more important thing. It needs to ensure that the libmali library in the system uses the correct version, because mpv renders the image through gbm, so libmali.so needs to use this version: libmali-midgard-t86x -r14p0-gbm.so, which means that this version of mpv can only be used under FriendlyCore, can not be used under X11 Desktop.
Mpv official use guide：https://github.com/mpv-player/mpv/wiki

8 Features applicable to FriendlyDesktop and FriendlyCore

8.1 Using Camera on Linux (MIPI Camera OV13850 & OV4689, and webcam logitect C920)

Hardware Setting: The Camera module can be connected to a MIPI port:

FriendlyELEC provides some scripts use to test a camera's functions. You can run it in a commandline to test picture taking and video recording.
You may try update this script to the lastest version by using the following commands:

cd /tmp/
git clone https://github.com/friendlyarm/gst-camera-sh.git
sudo cp gst-camera-sh/*.sh /usr/bin/

There are three scripts:
gst-camera.sh: preview, photo and video of a single camera
dual-camera.sh: preview two cameras
stop-gst-camera.sh: stop preview

8.1.1 Options in "gst-camera.sh"

Options	Comment
--index or -i	Camera's index, it can be either 0 or 1. When two cameras are connected to a board you need to specify 1 to access the second camera.
--action or -a	Specify an action, it can be "preview" to preview, "photo" to take a picture or "video" to record video
--output or -o	Specify an output file to save a picture when taking a picture or video file when recording video
--verbose or -v	If it is specified as "yes" it will output the complete command when "gst-launch-1.0" is called
-x	Using the rkximagesink plugin, the preview image will be output to the X11 window for the FriendlyDesktop and Lubuntu systems
-g	Using the glimagesink plugin, the preview image will be output to the X11 window for the FriendlyDesktop and Lubuntu systems
-k	Using the kmssink plugin, the preview image will be output directly to the screen for the FriendlyCore system

The script gst-camera.sh will automatically recognize OV13850, OV4689 and C920 camera, and then pass the appropriate parameters to gst-launch-1.0.

8.1.2 Usage of gst-camera.sh

• Preview

gst-camera.sh --action preview

• Picture Taking

You can run the following command to take a picture and save it as a "1.jpg" file,

gst-camera.sh -a photo -o 1.jpg

• Preview and Record

You can run the following command to record video and save your video to a "1.ts" file. Hardware encoding is activated when it is recording video.

gst-camera.sh --action video -output 1.ts

• Show Complete Command

If you add the "--verbose yes" option it will show a complete gsteamer command.

gst-camera.sh --action video --output 1.ts --verbose yes

Here is the complete gsteamer command you will see:

gst-launch-1.0 rkisp num-buffers=512 device=/dev/video0 io-mode=1 ! \
    video/x-raw,format=NV12,width=1280,height=720,framerate=30/1 ! \
        mpph264enc ! queue ! h264parse ! mpegtsmux ! \
        filesink location=/tmp/camera-record.ts

• Preview dual camera

Connect two mipi cameras, or one mipi camera and one usb camera (tested only: Logitech C920 pro), call the following command：

dual-camera.sh

Note: It is recommended to test this on FriendlyDesktop.

8.1.3 gst-launch-1.0 parameter description

Preview camera on FriendlyDesktop：

gst-launch-1.0 rkisp device=/dev/video1 io-mode=4 ! video/x-raw,format=NV12,width=1280,height=720,framerate=30/1 ! rkximagesink

Important parameters

parameter	description
device	preview device(selfpath): /dev/video1 and /dev/video5, picture device(mainpath): /dev/video0 and /dev/video4, webcam device: /dev/video8
io-mode	1: memory map, 4:dmabuf
rkximagesink/glimagesink/kmssink	rkximagesink for FriendlyDesktop, kmssink for FriendlyCore, glimagesink for webcam on FriendlyDesktop

8.1.4 Access the camera in OpenCV

MIPI camera：

cv.VideoCapture('rkisp device=/dev/video1 io-mode=4 ! video/x-raw,format=NV12,width=640,height=480,framerate=30/1 ! videoconvert ! appsink', cv.CAP_GSTREAMER)

USB camera：

cv.VideoCapture('rkisp device=/dev/video8 io-mode=4 ! videoconvert ! video/x-raw,format=NV12,width=640,height=480,framerate=30/1 ! videoconvert ! appsink', cv.CAP_GSTREAMER)

Please refer to the sample code here for details：https://github.com/friendlyarm/install-opencv-on-friendlycore/tree/rk3399/examples

8.1.5 Camera application tutorial: Push video stream

Please refre this guide: How to setup RTMP server on NanoPC-T4

8.1.6 Reference resource

http://blog.iotwrt.com/media/2017/10/01/camera/ http://www.360doc.com/content/16/1019/17/496343_599664458.shtml

8.2 How to install and use docker

8.2.1 How to Install Docker

Run the following commands：

wget https://download.docker.com/linux/ubuntu/dists/bionic/pool/stable/arm64/containerd.io_1.2.6-3_arm64.deb
wget https://download.docker.com/linux/ubuntu/dists/bionic/pool/stable/arm64/docker-ce-cli_19.03.2~3-0~ubuntu-bionic_arm64.deb
wget https://download.docker.com/linux/ubuntu/dists/bionic/pool/stable/arm64/docker-ce_19.03.2~3-0~ubuntu-bionic_arm64.deb
sudo dpkg -i containerd.io_1.2.6-3_arm64.deb
sudo dpkg -i docker-ce-cli_19.03.2~3-0~ubuntu-bionic_arm64.deb
sudo dpkg -i docker-ce_19.03.2~3-0~ubuntu-bionic_arm64.deb

8.2.2 Test Docker installation

Test that your installation works by running the simple docker image:

git clone https://github.com/friendlyarm/debian-jessie-arm-docker
cd debian-jessie-arm-docker
./rebuild-image.sh
./run.sh

8.3 Using ffmpeg (video hardware decoding)

Both FriendlyCore and FriendlyDesktop systems are built-in ffmpeg, with bin file, static libraries, and header files, all stored in the /usr/ffmpeg-rkmp directory.
ffmpeg supports the RockChip MPP video decoder, for details, please refer to: https://trac.ffmpeg.org/wiki/HWAccelIntro

Test the decoding performance of 4K video:

/usr/ffmpeg-rkmp/bin/ffmpeg -benchmark -loglevel 48 -vcodec h264_rkmpp -i 4K-Chimei-inn-60mbps.mp4 -map 0:v:0 -f null -

The results are shown below:

To play the video, you can use the ffmpeg-based player mpv. The 4K video used for the above test can be found in the test-video directory of the network disk. The network address is http://dl.friendlyelec.com/nanopct4.

9 Work with Lubuntu

See here: Lubuntu desktop 16.04 for RK3399

10 Work with Android 8.1

FriendlyElec provides a full Android8.1 BSP for NanoPi-NEO4. The source code is hosted at gitlab.com and is open source. The BSP supports GPU and VPU hardware acceleration.

10.1 Connect MIPI Camera to NanoPi-NEO4

FriendlyElec developed a MIPI camera CAM1320 for board and it works under Android. You can use this camera to take pictures and record video. The operation is straightforward. You just need to connect the camera at your board's MIPI interface, boot your board to Android and start Android's camera app.
The board has one MIPI interfaces：
MIPI-CSI1 <--> Android rear camera

How to connect：

10.2 Use dual MIPI camera preview and video

Download the sample source code below from github and compile and run it：

git clone https://github.com/friendlyarm/Dual-Camera.git -b working-branch

After the application is installed, you need to Set Android permissions to make the demo run normally. The method is enter system ui: Settings -> Apps & notifications -> Dual Camera -> Permissions, Select the following permissions：

Camera
Microphone
Storage

The gui looks like this：

Click the "CAPTURE VIDEO" button on the gui to record the video (two cameras at the same time), and the video file will be saved to the following location.：/storage/emulated/0/Download/dualcamera_h264.mp4. Known issue：
Recorded video file will play faster than normal, may need to adjust some parameters of mediacodec.

10.3 Change system language

The default system language of Android system is English. For example, if we want to set it to Chinese, the steps are as follows: 1) Go to Android settings：Settings -> System -> Languages & Input -> Languages;
2）Click "Add a language", Select "简体中文", and then select "中国";
3) At this time, there will be two languages, Chinese and English. Drag the Chinese item to the top of the list. Note that if you are using a mouse, drag it by placing the mouse pointer on the right side of the list item. On the icon and then press the middle mouse button to drag;

10.4 Android8.1 hardware access

You can use the FriendlyThings SDK to access and control hardware resources on the motherboard in the Android App, such as Uart, SPI, I2C, GPIO and other interfaces. For details, please refer to the following two documents.：

• Android: FriendlyThings for Rockchip
• Android: FriendlyThings APIs

10.5 Android Neural Networks SDK Sample

Android8.1 BSP comes pre-installed with Rockchip's Android NN SDK for Android 8.1, supporting GPU acceleration.。
Sample program for Android NN pre-installed in the Android8 firmware we provide：TfLiteCameraDemo，This is a MobileNet classifier demo using Rockchip AndroidNN GPU acceleration，The camera module is required to be connected to the motherboard during operation. The USB camera and CSI camera are supported，The sample program is launched by clicking the "TfLiteCameraDemo" icon on the home page. The running effect is as follows：


For a detailed description of the Android NN SDK, you can refer to this document：[RK3399_Android8.1_AndroidNN_SDK_V1.0_20180605发布说明.pdf]
TfLiteCameraDemo sample source code download link：[TfLiteCameraDemo source code]

10.6 Using the adb

1. The first time you start the system, if you need to change the system files, you need to turn off security verification (note: apk installation does not need to be closed), and restart after turning off security verification

adb root
adb disable-verity
adb reboot

2. After restarting, get root and remount /system to enable write permissions

adb root
adb remount

3. Upload a file

adb push example.txt /system/

10.7 HDMI resolution and overscan setting

If an HDMI display device is connected, go to Android Settings -> Display -> Advanced -> HDMI & Rotation to set it up.

HDMI Resolution	The default is Auto, you can manually set the display resolution, up to 4K resolution
Screen Zoom	click the four arrow buttons in the middle to adjust the zoom
Display Rotation	for horizontal and vertical screen switching

10.8 Screen rotation

go to Android Settings -> Display -> Advanced -> HDMI & Rotation to set it up.

Use the following command in shell to test screen rotation (Settings not saved)：

wm rotation 90

10.9 Hide Navigation bar

Enter Settings -> Accessibility, Turn on immersive mode, and then open an Android application, For example: Lightning, it will be in full screen mode.

10.10 Switch audio output channel

You can configure the audio output to the HDMI or headphone jack, Setting interface entry method: Android Settings -> Accessibility -> Force audio output. If the Force audio output menu item is gray, that is, it is in an unselectable state, the hardware you are using will automatically detect the headphone plug-in status and automatically switch the audio channel without setting.

10.11 Adjust the volume of the recording

1) First use the amix command to adjust the volume of the recording through the serial port or the adb shell with root privileges, for example:

Amix "IN2 Boost"
Amix "ADC Capture Volume"

The above command is used to view the current settings.
2) After debugging, modify the value of the corresponding configuration item in the rt5651_main_mic_capture_controls array in the hardware/rockchip/audio/tinyalsa_hal/codec_config/rt5651_config.h file, compile the Android source code and test it.

10.12 Custom logo and boot animation

10.12.1 On/Off

Change:
BOOT_SHUTDOWN_ANIMATION_RINGING := false
to:
BOOT_SHUTDOWN_ANIMATION_RINGING := true
in device/rockchip/common/BoardConfig.mk file.

10.12.2 Boot animation

Create or replace the following files in the Android source code directory：
kernel/logo.bmp
kernel/logo_kernel.bmp
device/rockchip/common/bootshutdown/bootanimation.zip

10.12.3 Shutdown animation

Create or replace the following files in the Android source code directory：
device/rockchip/common/bootshutdown/shutdownanimation.zip

10.12.4 How to make animation

Please refre to：http://blog.sina.com.cn/s/blog_4960586c0100vu5v.html

10.13 Remove Google Framework

If you don't need to use the google service, you can delete the Google framework to save system resources by deleting the following directory in the Android source code and recompiling Android:
vendor/google

10.14 Work with USB Camera to Take Pictures and Record Video

FriendlyELEC's Android system supports picture taking and video recording with a USB camera, Android's camera app has these functions. When you use the app to take pictures or record video you need to be aware of the following two things:
1) Make sure your camera's resolution works. We suggest you try a camera with a lower CIF resolution first. If it works you may switch to a camera with a higher resolution:
;
2）A USB camera cannot work simultaneously with a MIPI camera. Plug and play is not supporter for camera modules. After you connect a camera to a board you need to reboot your board to enable the camera.

Here are the camera modules we tested: Logitech C270 and LogitechC922 PRO
In our test the resolution was 1080P when we used a Logitech C922 PRO to take pictures or record video.

10.15 Using 4G Module EC20 on Android

10.15.1 Hardware Setup

Connect an EC20 module to a USB to miniPCIe board and connect the board to an ARM board's USB Host. Here is a hardware setup:

Power on the board and you will be able to surf the internet with the 4G module like using an Android phone.

10.15.2 Activate EC20's GPS Functions

By default GPS functions are disabled in Android. If GPS functions are enabled in Android but no GPS module is detected Android will continuously output log messages. After an EC20 module is connected you can enable GPS functions.
To enable the GPS functions open the "vendor/quectel/ec20/BoardConfigPartial.mk" file and change the following line:

BOARD_HAS_GPS := false

to

BOARD_HAS_GPS := true

and recompile Android。

11 Work with Android7.1

See here: Android7

11.1 Build Openwrt/Friendlywrt

11.1.1 Download Code

Two versions are available, please choose as required:

11.1.1.1 FriendlyWrt 21.02

mkdir friendlywrt21-rk3399
cd friendlywrt21-rk3399
git clone https://github.com/friendlyarm/repo --depth 1 tools
tools/repo init -u https://github.com/friendlyarm/friendlywrt_manifests -b master-v21.02 \
        -m rk3399.xml --repo-url=https://github.com/friendlyarm/repo  --no-clone-bundle
tools/repo sync -c  --no-clone-bundle

11.1.1.2 FriendlyWrt 23.05

mkdir friendlywrt23-rk3399
cd friendlywrt23-rk3399
git clone https://github.com/friendlyarm/repo --depth 1 tools
tools/repo init -u https://github.com/friendlyarm/friendlywrt_manifests -b master-v23.05 \
        -m rk3399.xml --repo-url=https://github.com/friendlyarm/repo  --no-clone-bundle
tools/repo sync -c  --no-clone-bundle

11.1.2 First compilation step

./build.sh rk3399.mk  # or rk3399-docker.mk

All the components (including u-boot, kernel, and friendlywrt) are compiled and the sd card image will be generated, then execute the following command to generate the image file for installing the system into the emmc:

./build.sh emmc-img

After making changes to the project, the sd card image needs to be repackaged by running the following command:

./build.sh sd-img

11.1.3 Secondary compilation steps

cd friendlywrt
make menuconfig
rm -rf ./tmp
make -j${nproc}
cd ../
./build.sh sd-img
./build.sh emmc-img

11.1.4 Build u-boot only

./build.sh uboot

11.1.5 Build kernel only

./build.sh kernel

11.1.6 Build friendlywrt only

./build.sh friendlywrt

Or go to the friendlywrt directory and follow the standard openwrt commands. If you get an error with the above command, try using the following command to compile in a single thread:

cd friendlywrt
make -j1 V=s

11.2 Build Buildroot

please refer to: Buildroot

11.3 Build Other Linux

11.3.1 Kernel and u-boot versions

Operating System	Kernel Version	U-boot version	Cross-compiler	Partition type	Packaging Tool	Kernel branch	Kernel configuration	U-boot branch	U-boot configuration
lubuntu	linux v4.4.y	u-boot v2014.10	6.4-aarch64	MBR	sd-fuse	nanopi4-linux-v4.4.y	nanopi4_linux_defconfig	nanopi4-v2014.10_oreo	rk3399_defconfig
friendlycore-arm64
friendlydesktop-arm64
eflasher
buildroot	linux v4.19.y	u-boot v2017.09	11.3-aarch64	GPT	sd-fuse	nanopi4-v4.19.y	nanopi4_linux_defconfig	nanopi4-v2017.09	nanopi4_defconfig
ubuntu-focal-desktop-arm64
debian-bullseye-desktop-arm64
debian-bullseye-minimal-arm64
friendlycore-focal-arm64
debian-bookworm-core-arm64
ubuntu-noble-core-arm64
openmediavault-arm64	linux v6.1.y	u-boot v2017.09	11.3-aarch64	GPT	sd-fuse	nanopi-r2-v6.1.y	nanopi4_linux_defconfig
friendlywrt21				GPT			nanopi4_linux_defconfig +friendlywrt.config
friendlywrt21-docker
friendlywrt23
friendlywrt23-docker

• Kernel git repo：https://github.com/friendlyarm/kernel-rockchip
• U-boot git repo：https://github.com/friendlyarm/uboot-rockchip
• The cross-compile toolchain is located in the path: /opt/FriendlyARM/toolchain/
• The SD-Fuse is a helper script to make bootable SD card image.
• Click on MBR and GPT in the table to view the partition layout (configuration file) for each system.

11.3.2 Build kernel linux-v4.4.y

This section applies to the following operating systems:

lubuntu

eflasher

friendlydesktop-arm64

friendlycore-arm64

Clone the repository to your local drive then build:

git clone https://github.com/friendlyarm/kernel-rockchip --single-branch --depth 1 -b nanopi4-linux-v4.4.y kernel-rockchip
cd kernel-rockchip
export PATH=/opt/FriendlyARM/toolchain/6.4-aarch64/bin/:$PATH
touch .scmversion
# Load configuration
make ARCH=arm64 CROSS_COMPILE=aarch64-linux- nanopi4_linux_defconfig
# Optionally, if you want to change the default kernel config
# make ARCH=arm64 CROSS_COMPILE=aarch64-linux- menuconfig  
# Start building kernel
make ARCH=arm64 CROSS_COMPILE=aarch64-linux- nanopi4-images -j$(nproc)
# Start building kernel modules
mkdir -p out-modules
make ARCH=arm64 CROSS_COMPILE=aarch64-linux- INSTALL_MOD_PATH="$PWD/out-modules" modules -j$(nproc)
make ARCH=arm64 CROSS_COMPILE=aarch64-linux- INSTALL_MOD_PATH="$PWD/out-modules" modules_install
KERNEL_VER=$(make CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 kernelrelease)
rm -rf $PWD/out-modules/lib/modules/${KERNEL_VER}/kernel/drivers/gpu/arm/mali400/
[ ! -f "$PWD/out-modules/lib/modules/${KERNEL_VER}/modules.dep" ] && depmod -b $PWD/out-modules -E Module.symvers -F System.map -w ${KERNEL_VER}
(cd $PWD/out-modules && find . -name \*.ko | xargs aarch64-linux-strip --strip-unneeded)

After the compilation, the following files will be generated:

kernel.img

resource.img

The kernel modules are located in the out-modules directory

Run your build:
Please refre to #Running the build

11.3.3 Build u-boot v2014.10

This section applies to the following operating systems:

lubuntu

eflasher

friendlydesktop-arm64

friendlycore-arm64

Clone the repository to your local drive then build:

git clone https://github.com/friendlyarm/uboot-rockchip --single-branch --depth 1 -b nanopi4-v2014.10_oreo
cd uboot-rockchip
export PATH=/opt/FriendlyARM/toolchain/6.4-aarch64/bin/:$PATH
make CROSS_COMPILE=aarch64-linux- rk3399_defconfig
make CROSS_COMPILE=aarch64-linux-

After the compilation, the following files will be generated:

uboot.img

trust.img

rk3399_loader_v1.22.119.bin (aka MiniLoaderAll.bin)

Installing the u-boot:
Please refre to #Running the build

11.3.4 Build kernel linux-v4.19.y

This section applies to the following operating systems:

ubuntu-focal-desktop-arm64

debian-bullseye-desktop-arm64

debian-bullseye-minimal-arm64

friendlycore-focal-arm64

ubuntu-noble-core-arm64

debian-bookworm-core-arm64

buildroot

Clone the repository to your local drive then build:

git clone https://github.com/friendlyarm/kernel-rockchip --single-branch --depth 1 -b nanopi4-v4.19.y kernel-rockchip
cd kernel-rockchip
export PATH=/opt/FriendlyARM/toolchain/11.3-aarch64/bin/:$PATH
touch .scmversion
# Configuring the Kernel
# Load default configuration
make ARCH=arm64 CROSS_COMPILE=aarch64-linux- nanopi4_linux_defconfig
# Optionally, load configuration for FriendlyWrt
# make ARCH=arm64 CROSS_COMPILE=aarch64-linux- nanopi4_linux_defconfig friendlywrt.config
# Optionally, if you want to change the default kernel config
# make ARCH=arm64 CROSS_COMPILE=aarch64-linux- menuconfig
# Start building kernel
make ARCH=arm64 CROSS_COMPILE=aarch64-linux- nanopi4-images -j$(nproc)
# Start building kernel modules
mkdir -p out-modules
make ARCH=arm64 CROSS_COMPILE=aarch64-linux- INSTALL_MOD_PATH="$PWD/out-modules" modules -j$(nproc)
make ARCH=arm64 CROSS_COMPILE=aarch64-linux- INSTALL_MOD_PATH="$PWD/out-modules" modules_install
KERNEL_VER=$(make CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 kernelrelease)
rm -rf $PWD/out-modules/lib/modules/${KERNEL_VER}/kernel/drivers/gpu/arm/mali400/
[ ! -f "$PWD/out-modules/lib/modules/${KERNEL_VER}/modules.dep" ] && depmod -b $PWD/out-modules -E Module.symvers -F System.map -w ${KERNEL_VER}
(cd $PWD/out-modules && find . -name \*.ko | xargs aarch64-linux-strip --strip-unneeded)

After the compilation, the following files will be generated:

kernel.img

resource.img

The kernel modules are located in the out-modules directory

Run your build:
Please refre to #Running the build

11.3.5 Build kernel linux-v6.1.y

This section applies to the following operating systems:

friendlywrt21

friendlywrt21-docker

friendlywrt23

friendlywrt23-docker

openmediavault-arm64

Clone the repository to your local drive then build:

git clone https://github.com/friendlyarm/kernel-rockchip --single-branch --depth 1 -b nanopi-r2-v6.1.y kernel-rockchip
cd kernel-rockchip
export PATH=/opt/FriendlyARM/toolchain/11.3-aarch64/bin/:$PATH
touch .scmversion
# Configuring the Kernel
# Load default configuration
make CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 nanopi4_linux_defconfig
# Optionally, load configuration for FriendlyWrt
# make CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 nanopi4_linux_defconfig friendlywrt.config
# Optionally, if you want to change the default kernel config
# make CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 menuconfig
# Start building kernel
make CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 -j$(nproc)
# Start building kernel modules
mkdir -p out-modules && rm -rf out-modules/*
make CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 INSTALL_MOD_PATH="$PWD/out-modules" modules -j$(nproc)
make CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 INSTALL_MOD_PATH="$PWD/out-modules" modules_install
KERNEL_VER=$(make CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 kernelrelease)
[ ! -f "$PWD/out-modules/lib/modules/${KERNEL_VER}/modules.dep" ] && depmod -b $PWD/out-modules -E Module.symvers -F System.map -w ${KERNEL_VER}
(cd $PWD/out-modules && find . -name \*.ko | xargs aarch64-linux-strip --strip-unneeded)

Pack the kernel.img and resource.img:

wget https://raw.githubusercontent.com/friendlyarm/sd-fuse_rk3399/kernel-6.1.y/tools/mkkrnlimg && chmod 755 mkkrnlimg
wget https://raw.githubusercontent.com/friendlyarm/sd-fuse_rk3399/kernel-6.1.y/tools/resource_tool && chmod 755 resource_tool
wget https://raw.githubusercontent.com/friendlyarm/sd-fuse_rk3399/kernel-6.1.y/prebuilt/boot/logo.bmp
wget https://raw.githubusercontent.com/friendlyarm/sd-fuse_rk3399/kernel-6.1.y/prebuilt/boot/logo_kernel.bmp
./mkkrnlimg arch/arm64/boot/Image kernel.img
mkdir kernel-dtbs
cp -f arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dtb kernel-dtbs/rk3399-nanopi4-rev09.dtb
cp -f arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dtb kernel-dtbs/rk3399-nanopi4-rev0a.dtb
cp -f arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4se.dtb kernel-dtbs/rk3399-nanopi4-rev0b.dtb
cp -f arch/arm64/boot/dts/rockchip/rk3399-nanopc-t4.dtb kernel-dtbs/rk3399-nanopi4-rev00.dtb
./resource_tool --dtbname kernel-dtbs/*.dtb logo.bmp logo_kernel.bmp

After the compilation, the following files will be generated:

kernel.img

resource.img

The kernel modules are located in the out-modules directory

Run your build:
Please refre to #Running the build

11.3.6 Build u-boot v2017.09

This section applies to the following operating systems:

ubuntu-focal-desktop-arm64

debian-bullseye-desktop-arm64

debian-bullseye-minimal-arm64

friendlycore-focal-arm64

ubuntu-noble-core-arm64

debian-bookworm-core-arm64

buildroot

Clone the repository to your local drive then build:

git clone https://github.com/friendlyarm/rkbin --single-branch --depth 1 -b friendlyelec
git clone https://github.com/friendlyarm/uboot-rockchip --single-branch --depth 1 -b nanopi4-v2017.09
export PATH=/opt/FriendlyARM/toolchain/11.3-aarch64/bin/:$PATH
cd uboot-rockchip/
./make.sh nanopi4

After the compilation, the following files will be generated:

uboot.img

trust.img

rk3399_loader_v1.24.126.bin (aka MiniLoaderAll.bin)

Run your build:
Please refre to #Running the build

11.3.7 Running the build

11.3.7.1 Install to target board

11.3.7.1.1 MBR partition

This section applies to the following operating systems:

lubuntu

eflasher

friendlydesktop-arm64

friendlycore-arm64

The MBR partitioning is only used by the Linux v4.4 kernel. You can check the partition layout by clicking on this link: partmap. To write an image file, you can use the dd command. For example, in the parameter.template file, "0x00014000@0x00014000(kernel)" specifies that the kernel partition starts at 0x00014000, which is equivalent to 81920 in decimal. Therefore, the dd command should be as follows:

dd if=kernel.img of=/dev/mmcblk0 seek=81920

11.3.7.1.2 GPT partition

This section applies to the following operating systems:

ubuntu-focal-desktop-arm64	debian-bookworm-core-arm64	debian-bullseye-desktop-arm64	debian-bullseye-minimal-arm64
friendlycore-focal-arm64	ubuntu-noble-core-arm64	friendlywrt21-kernel4	buildroot
friendlywrt21	friendlywrt21-docker	friendlywrt23	friendlywrt23-docker

The OS uses GPT partitions by default which is using the Linux v4.19 and Linux v5.15 kernel, you can use the dd command, but be careful to choose the right output device:

• The SD/TF Card device node: /dev/mmcblk0
  
• The eMMC device node: /dev/mmcblk2
  

The following is an example of how to update the kernel to eMMC:
Use the 'parted' command to view the partition layout:

parted /dev/mmcblk2 print

Sample outputs:

Model: MMC BJTD4R (sd/mmc)
Disk /dev/mmcblk2: 31.3GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
 
Number  Start   End     Size    File system  Name      Flags
 1      8389kB  12.6MB  4194kB               uboot
 2      12.6MB  16.8MB  4194kB               trust
 3      16.8MB  21.0MB  4194kB               misc
 4      21.0MB  25.2MB  4194kB               dtbo
 5      25.2MB  41.9MB  16.8MB               resource
 6      41.9MB  83.9MB  41.9MB               kernel
 7      83.9MB  134MB   50.3MB               boot
 8      134MB   2500MB  2366MB  ext4         rootfs
 9      2500MB  31.3GB  28.8GB  ext4         userdata

as shown above, the resource partition is located at 5 and the kernel partition is located at 6. Use the dd command to write the resource.img and kernel.img files to these partitions, the commands are as follows:

dd if=resource.img of=/dev/mmcblk2p5 bs=1M
dd if=kernel.img of=/dev/mmcblk2p6 bs=1M

If you want to update u-boot:

dd if=uboot.img of=/dev/mmcblk2p1 bs=1M

To update new driver modules, copy the newly compiled driver modules to the appropriate directory under /lib/modules.

11.3.7.2 Packaging and creating an SD image

To create a new OS image file, you need to use the "sd-fuse" packaging tool.

"sd-fuse" is a collection of scripts that can be used to create bootable SD card images for FriendlyElec boards. Its main features include:

• Creation of root filesystem images from a directory
  
• Building of bootable SD card images
  
• Simple compilation of kernel, U-Boot, and third-party drivers
  

Please click on the following link to find out more:

Kernel version	Packaging Tool
linux v4.4.y	sd-fuse
linux v4.19.y	sd-fuse_rk3399/kernel-4.19
linux v6.1.y	sd-fuse_rk3399/kernel-6.1.y

11.3.7.3 USB flashing

Note: kernel v4.4.y is not supported

11.3.7.3.1 Linux

Reboot the board and enter loader mode with the following command:

sudo reboot loader

To flash U-Boot and kernel using the "upgrade_tool_v2.17_for_linux" tool, please use the following command:

sudo upgrade_tool di -k kernel.img
sudo upgrade_tool di -re resource.img
sudo upgrade_tool di -u uboot.img
sudo upgrade_tool RD

Note: "upgrade_tool" is a command-line tool provided by Rockchip for Linux operating systems (Linux_Upgrade_Tool).

11.4 Build the code using scripts

11.4.1 Download scripts and image files

git clone https://github.com/friendlyarm/sd-fuse_rk3399.git -b kernel-4.19
cd sd-fuse_rk3399
wget http://112.124.9.243/dvdfiles/RK3399/images-for-eflasher/friendlycore-focal-arm64-images.tgz
tar xvzf friendlycore-focal-arm64-images.tgz

11.4.2 Compile the kernel

Download the kernel source code and compile it. the relevant image files in the friendlycore-focal-arm64 directory will be automatically updated, including the kernel modules in the file system:

git clone https://github.com/friendlyarm/kernel-rockchip --depth 1 -b nanopi4-v4.19.y kernel-rk3399
KERNEL_SRC=$PWD/kernel-rk3399 ./build-kernel.sh friendlycore-focal-arm64

11.4.3 Compile the kernel headers

git clone https://github.com/friendlyarm/kernel-rockchip --depth 1 -b nanopi4-v4.19.y kernel-rk3399
MK_HEADERS_DEB=1 BUILD_THIRD_PARTY_DRIVER=0 KERNEL_SRC=$PWD/kernel-rk3399 ./build-kernel.sh friendlycore-focal-arm64

11.4.4 Compile the uboot

Download the uboot source code and compile it. the relevant image files in the friendlycore-focal-arm64 directory will be automatically updated:

git clone https://github.com/friendlyarm/uboot-rockchip --depth 1 -b nanopi4-v2017.09
UBOOT_SRC=$PWD/uboot-rockchip ./build-uboot.sh friendlycore-focal-arm64

11.4.5 Generate new image

Repackage the image file in the friendlycore-focal-arm64 directory into sd card image:

./mk-sd-image.sh friendlycore-focal-arm64

After the command is completed, the image is in the out directory, you can use the dd command to make the SD boot card, for example:

dd if=out/rk3399-sd-friendlycore-focal-4.19-arm64-YYYYMMDD.img of=/dev/sdX bs=1M

11.5 Building AOSP from source

11.5.1 Hardware and Software Requirements

• Your computer should have at least 16GB of RAM and 300GB of disk space. We recommend using a machine with 32GB of RAM and a large-capacity, high-speed SSD, and we do not recommend using virtual machines.
• If you encounter compilation errors, they may be caused by problems with the compilation environment. We recommend using the following Docker container for compilation: docker-cross-compiler-novnc.

11.5.2 Compile Android10

11.5.2.1 Download Android10 Source Code

There are two ways to download the source code:

• repo archive file on netdisk

Netdisk URL: Click here
File location on netdisk："07_Source codes/rk3399-android-10.git-YYYYMMDD.tar.xz" (YYYYMMDD means the date of packaging)
After extracting the repo package from the network disk, you need to execute the sync.sh script, which will pull the latest code from gitlab:

tar xf "/path/to/netdisk/07_Source codes/rk3399-android-10.git-YYYYMMDD.tar.xz"
cd rk3399-android-10
./sync.sh

• git clone from gitlab

NanoPi-NEO4 source code is maintained in gitlab, You can download it by running the following command:

git clone --recursive https://gitlab.com/friendlyelec/rk3399-android-10.git -b main

Note: If the following error "error: unknown option `recurse-submodules'" appears, please upgrade git to v2.0.0 or above.

11.5.2.2 Generate Image File

You can compile an Android source code and generate an image file (non-root user is recommended):

cd rk3399-android-10
./build-nanopc-t4.sh -F -M

If you need to include google apps, you need to set an environment variable and then compile, as shown below:

cd rk3399-android-10
export INSTALL_GAPPS_FOR_TESTING=yes
./build-nanopc-t4.sh -F -M

11.5.2.3 Make OTA Packages

If you need the support of A/B (Seamless) System Updates, you need to do the following:
a) Build your own update server for http download of update files;
b) Customize the Updater application, the code is located in packages/apps/Updater, let it connect and download file from your server;
c) Use the quick compilation script parameter -O or --ota to compile OTA Packages, as shown below:

cd rk3399-android-10
./build-nanopc-t4.sh -F -O -M

After the compilation is successfully completed, the OTA update related packages are located in the directory: rockdev/otapackage/ ，Please do not delete this directory.
After you have made some changes, compiling again with the parameter -O will generate ota-update-XXXXXXXX.zip, which is an incremental update package.
OTA Packages decides whether to generate incremental update package according to BUILD_NUMBER, for details, please refer to build-nanopc-t4.sh.
To disable the A/B feature, you can refer to the following to modify device/rockchip/rk3399/nanopc-t4/BoardConfig.mk, and then recompile uboot and android:

BOARD_USES_AB_IMAGE := false

11.5.2.4 Update System with New Image

After compilation is done a new image file will be generated in the "rockdev/Image-nanopc_t4/" directory under Android 10's source code directory. You can follow the steps below to update the OS in NanoPi-NEO4:
1) Insert an SD card which is processed with EFlasher to an SD card reader and insert this reader to a PC running Ubuntu. The SD card's partitions will be automatically mounted;
2) Copy all the files under the "rockdev/Image-nanopc_t4/" directory to the SD card's android10 directory in the "FRIENDLYARM" partition;
3) Insert this SD card to NanoPi-NEO4 and reflash Android
When flashing Android 10, EFlasher requires v1.3 or above. When flashing with Type-C, please use the tool AndroidTool v2.71 or Linux_Upgrade_Tool v1.49 provided by Rockchip.

11.5.3 Compile Android8.1

11.5.3.1 Download Android8.1 Source Code

There are two ways to download the source code:

• repo archive file on netdisk

Netdisk URL: Click here
File location on netdisk：sources/rk3399-android-8.1.git-YYYYMMDD.tgz (YYYYMMDD means the date of packaging)
After extracting the repo package from the network disk, you need to execute the sync.sh script, which will pull the latest code from gitlab:

tar xvzf /path/to/netdisk/sources/rk3399-android-8.1.git-YYYYMMDD.tgz
cd rk3399-android-8.1
./sync.sh

• git clone from gitlab

NanoPi-NEO4 source code is maintained in gitlab, You can download it by running the following command:

git clone https://gitlab.com/friendlyelec/rk3399-android-8.1 --depth 1 -b master

11.5.3.2 Generate Image File

You can compile an Android source code and generate an image file:

cd rk3399-android-8.1
./build-nanopc-t4.sh -F -M

11.5.3.3 Update System with New Image

After compilation is done a new image file will be generated in the "rockdev/Image-nanopc_t4/" directory under Android 8.1's source code directory. You can follow the steps below to update the OS in NanoPi-NEO4:
1) Insert an SD card which is processed with EFlasher to an SD card reader and insert this reader to a PC running Ubuntu. The SD card's partitions will be automatically mounted;
2) Copy all the files under the "rockdev/Image-nanopc_t4/" directory to the SD card's android8 directory in the "FRIENDLYARM" partition;
3) Insert this SD card to NanoPi-NEO4 and reflash Android
Here is an alternative guide to update OS: sd-fuse_rk3399

11.5.4 Compile Android7

11.5.4.1 Download Android7 Source Code

There are two ways to download the source code:

• repo archive file on netdisk

Netdisk URL: Click here
File location on netdisk：sources/rk3399-android-7.git-YYYYMMDD.tgz (YYYYMMDD means the date of packaging)
After extracting the repo package from the network disk, you need to execute the sync.sh script, which will pull the latest code from gitlab:

tar xvzf /path/to/netdisk/sources/rk3399-android-7.git-YYYYMMDD.tgz
cd rk3399-nougat
./sync.sh

• git clone from gitlab

NanoPi-NEO4 source code is maintained in gitlab, You can download it by running the following command:

git clone https://gitlab.com/friendlyelec/rk3399-nougat --depth 1 -b nanopc-t4-nougat

11.5.4.2 Generate Image File

You can compile an Android7 source code and generate an image file:

cd rk3399-nougat
./build-nanopc-t4.sh -F -M

11.5.4.3 Update System with New Image

After compilation is done a new image file will be generated in the "rockdev/Image-nanopc_t4/" directory under Android7's source code directory. You can follow the steps below to update the OS in NanoPi-NEO4:
1) Insert an SD card which is processed with EFlasher to an SD card reader and insert this reader to a PC running Ubuntu. The SD card's partitions will be automatically mounted;
2) Copy all the files under the "rockdev/Image-nanopc_t4/" directory to the SD card's android8 directory in the "FRIENDLYARM" partition;
3) Insert this SD card to NanoPi-NEO4 and reflash Android
Here is an alternative guide to update OS: sd-fuse_rk3399

12 The usage of eMMC module

12.1 Flash Image to eMMC

12.1.1 Download Image and Utilities

Visit download link to download image files and utilities.

Android OS
rk3399-eflasher-android10-YYYYMMDD.img.zip	Android10 image file
rk3399-eflasher-android8-YYYYMMDD.img.zip	Android8.1 image file
rk3399-eflasher-android7-YYYYMMDD.img.zip	Android7.1.2 image file
Linux OS
rk3399-eflasher-debian-bullseye-core-4.19-arm64-YYYYMMDD.img.gz	Debian 11(Bullseye) Core No desktop environment, command line only Kernel version 4.19.y
rk3399-eflasher-debian-buster-desktop-arm64-YYYYMMDD.img.gz	Debian 10(buster) Desktop, Uses LXDE as default desktop, Supports hardware acceleration, Kernel version 4.19.y
rk3399-eflasher-buildroot-4.19-arm64-YYYYMMDD.img.gz	Buildroot image file with Qt5-wayland (base on Rockchip Linux SDK)
rk3399-eflasher-friendlydesktop-bionic-4.4-arm64-YYYYMMDD.img.zip	64-bit FriendlyDesktop image file based on Ubuntu desktop 18.04 64bit
rk3399-eflasher-friendlycore-focal-4.19-arm64-YYYYMMDD.img.gz	64-bit FriendlyCore image file(Qt 5.10.0) based on Ubuntu core 20.04 64bit
rk3399-eflasher-friendlycore-bionic-4.4-arm64-YYYYMMDD.img.gz	64-bit FriendlyCore image file(Qt 5.10.0) based on Ubuntu core 18.04 64bit
rk3399-eflasher-lubuntu-desktop-xenial-4.4-armhf-YYYYMMDD.img.zip	Lubuntu Desktop(with Qt 5.10.0)
Linux Lite OS
rk3399-eflasher-friendlycore-lite-focal-5.10-arm64-20211029.img.zip	64-bit FriendlyCore Lite image file based on Ubuntu core 20.04 64bit, kernel version 5.15.y
rk3399-eflasher-friendlycore-lite-focal-4.19-arm64-20211029.img.zip	64-bit FriendlyCore Lite image file based on Ubuntu core 20.04 64bit, kernel version 4.19.y
FriendlyWrt
rk3399-eflasher-friendlywrt-21.02-YYYYMMDD.img.gz	FriendlyWrt image file, based on OpenWrt 21.02, kernel version 5.15.y
rk3399-eflasher-friendlywrt-21.02-docker-YYYYMMDD.img.gz	FriendlyWrt image file，based on OpenWrt 21.02, Pre-installed Docker，kernel version 5.15.y
rk3399-eflasher-friendlywrt-22.03-YYYYMMDD.img.gz	FriendlyWrt image file，based on OpenWrt 22.03，kernel version 5.15.y
rk3399-eflasher-friendlywrt-22.03-docker-YYYYMMDD.img.gz	FriendlyWrt image file，based on OpenWrt 22.03, Pre-installed Docker，kernel version 5.15.y
rk3399-eflasher-friendlywrt-kernel4-YYYYMMDD.img.zip	FriendlyWrt image file, based on OpenWrt 21.02, kernel version 4.19.y
Flash Utility:
win32diskimager.rar	Windows utility. Under Linux users can use "dd"

12.1.2 Flash Image to eMMC with eflasher and SD card

• Get an 8G SDHC card and backup its data if necessary;
• Download and extract the rk3399-eflasher-OSNAME-YYYYMMDD.img.zip and win32diskimager;
• Run the win32diskimager utility under Windows as administrator. On the utility's main window select your SD card's drive, the wanted image file EFlasher and click on "write" to start flashing the SD card. Under Linux run "dd" to flash the rk3399-eflasher-OSNAME-YYYYMMDD.img file to your SD card;
• Take out the SD and insert it to NanoPi-NEO4's microSD card slot;
• Power on NanoPi-NEO4 and it will be booted from your SD card and the EFlasher utility will be automatically launched. You can work with the EFlasher in multiple ways:

1: Connect an HDMI monitor and a USB mouse to your board and work with EFlasher's GUI;
2: Connect your board to a LAN, login onto the board with SSH and type "eflasher" in a commandline utility and proceed with prompts;(Note: when you login with SSH the username is root and the password is fa. Your board's IP address can be found by checking the router's system)
3: Login onto your board via a serial terminal and type "eflasher" to proceed;
4: Connect a lcd2usb to NanoPi-NEO4, press the K1 button on the LCD2USB board to select your wanted OS and press the K2 button to confirm. The installation process will be shown on lcd2usb;

• After installation is done turn off the board and take out the SD card from NanoPi-NEO4, power on the board and it will be booted from eMMC;

13 Using On-Board Hardware Resources

13.1 Access Serial Interface

For now only UART4 is available for users:

Serial Interface	Serial Device
UART0	Used by Bluetooth
UART1	Used by Gbps Ethernet
UART2	Used by Serial Debug Port
UART3	Used by Gbps Ethernet
UART4	Available, device name is /dev/ttyS4 (note: this is only applicable for ROM released after 20180618)

14 Source code repositories

NanoPi-NEO4's source code repositories
Android 8.1 Uboot	https://gitlab.com/friendlyelec/rk3399-android-8.1/tree/master/u-boot
Android 8.1 Linux-4.4.y Kernel	https://gitlab.com/friendlyelec/rk3399-android-8.1/tree/master/kernel
Android 8.1 BSP	https://gitlab.com/friendlyelec/rk3399-android-8.1 netdisk location: sources/rk3399-android-8.1.git-YYYYMMDD.tgz
Android 7.1.2 Uboot	https://gitlab.com/friendlyelec/rk3399-nougat/tree/nanopc-t4-nougat/u-boot
Android 7.1.2 Linux-4.4.y Kernel	https://gitlab.com/friendlyelec/rk3399-nougat/tree/nanopc-t4-nougat/kernel
Android 7.1.2 BSP	https://gitlab.com/friendlyelec/rk3399-nougat netdisk location: sources/rk3399-android-7.git-YYYYMMDD.tgz
FriendlyCore/FriendlyDesktop/Lubuntu Uboot	https://gitlab.com/friendlyelec/rk3399-android-8.1/tree/master/u-boot
FriendlyCore/FriendlyDesktop/Lubuntu Linux-4.4.y Kernel	https://github.com/friendlyarm/kernel-rockchip

15 Link to Rockchip Resources

• RK3399 datasheet V1.6
• RK3399TRM V1.4

16 Schematic, PCB CAD File

• Schematic: NanoPi-NEO4-1808-Schematic.pdf
• CAD document: NanoPi-NEO4-1808-Drawing(dxf).zip

17 Update Log

17.1 2024-04-21

17.1.1 OpenMediaVault

• Update to 7.0.5-1
• Update to Debian12

17.2 2024-03-15

17.2.1 Ubuntu focal desktop

• Fix the bluetooth issue

17.3 2024-01-31

17.3.1 Debian/Ubuntu/FriendlyCore/Buildroot

• Add adb support

17.4 2023-12-01

17.4.1 FriendlyWrt

• Update to kernel 6.1.63
• Update to openwrt-23.05.2

17.5 2023-10-31

17.5.1 Add a new system

• Add NAS system OpenMediaVault, base on Debian 11 with kernel 6.1

17.5.2 Debian Core/FriendlyCore-Lite-Core

• Update to kernel 6.1

17.5.3 FriendlyWrt

• Update to kernel 6.1
• Update to openwrt-23.05

17.6 2023-07-01

17.6.1 Debian11

• Update to the latest Rockchip sdk version, improve xserver and video playback performance
• Fix some known issues

17.7 2023-05-26

17.7.1 FriendlyWrt

• Updated v22.03 to openwrt-22.03.5
• Updated v21.02 to openwrt-21.02.7

17.8 2023-05-21

17.8.1 Debian11:

• Update to Rockchip sdk version linux-5.10-gen-rkr4
• Switch desktop to LXDE

17.9 2023-04-26

17.9.1 FriendlyWrt：

• Upgrade v22.03 to openwrt-22.03.4
• Upgrade v21.02 to openwrt-21.02.6

17.10 2023-02-10

17.10.1 Added Debian11

There are three versions:

• Debian11 Core: Command-line only
• Debian11 Minimal: With Xfce desktop, lite version
• Debian11 Desktop: With Xfce desktop, full version

17.11 2023-01-09

17.11.1 FriendlyCore：

• optimized the systemd service

17.12 2022-12-04

17.12.1 FriendlyWrt：

• Fix the issue that the storage space cannot be expanded
• Improve stability of the eMMC Tools

17.13 2022-09-06

17.13.1 FriendlyWrt：

• Improved eMMC read performance of NanoPi-R4SE
• Added Fullcone NAT support
• upgrade to 22.03.0
• Fix NanoPC-T4 eMMC stability issue

17.14 2022-08-19

17.14.1 Lubuntu/Android8/FriendlyDesktop：

• Add support for 7" screen HD703E
• Fixed FriendlyDesktop not booting from eMMC

17.14.2 Buildroot：

• Fix the issue of Som-RK3399 not loading WiFi module automatically

17.15 2022-08-03

17.15.1 FriendlyWrt：

• Upgrade FriendlyWrt to the latest version 22.03-rc6
• Fixed the problem that the R4S/R4SE may not recognize the pcie device (lan port) after a soft reboot (small probability)
• Fixed the issue where the R4SE status led did not reflect the burn progress when burning the system to eMMC
• Firewall settings adjustment: single-port devices (e.g. NanoPi-T4/NanoPi-M4) are set to allow WAN inbound traffic by default for easy web configuration, while multi-port devices are still denied WAN inbound traffic by default
• Updated FriendlyWrt firmware with 4.19 kernel to match FriendlyWrt 21.02 docker with 5.15 kernel

17.16 2022-07-27

17.16.1 FriendlyWrt:

• Beta version 22.03-rc3 is available, you can choose according to your package requirements, stable version 21.02.3 is recommended.
• Both docker and non-docker versions are available, all features are the same except for docker.
• Improved compatibility issues with third-party packages
• Added support for "Soft Factory Reset" function
• Added web-based tool eMMC-Tools, support install FriendlyElec and some third party firmware to eMMC, besides raw-image also support rockchip package format firmware
• Other details: default timezone setting to Shanghai, new NAS category menu, remove lcd2usb, improve security settings, tune sysctl parameters, fix docker firewall settings, etc.
• Add support for new hardware model: NanoPi-R4SE

17.17 2022-07-04

17.17.1 Debian 10(buster) Desktop (New)

• Uses LXDE as default desktop
• Pre-installed mpv, smplayer and chromium brower
• Supports hardware acceleration

17.18 2021-12-02

• Fixed the issue that some sd cards would cause the reboot command and watchdog not work (updated uboot v2017.09)

17.19 2021-10-29

17.19.1 FriendlyWrt：

• FriendlyWrt has been updated to the official stable version 21.02.1, features are basically the same as 19.07.5, support docker, usb wifi, etc.

17.19.2 Friendlycore-Focal

• Updated rockchip's video encoding/decoding (mpp) support
• Updated camera support, integrated rkisp_3A_server, after running it camera preview can use v4l2src directly, usage examples are as follows:

     rkisp_3A_server --mmedia /dev/media0 &
     gst-launch-1.0 v4l2src device=/dev/video1 io-mode=4 ! \
       video/x-raw,format=NV12,width=1280,height=720,framerate=30/1 ! queue ! kmssink

• Fix the issue that gst-camera.sh previews HDMI IN with errors

17.20 2021-08-31

17.20.1 FriendlyWrt：

• Upgraded kernel to 5.10.60
• Add a high-speed 5G USB WiFi support, the network card model is Comfast CF-WU782AC V2, the chip model is MediaTek MT7662
• Improved USB WiFi compatibility
• Improved PWM fan support, fan controlled by kernel drive, temperature control support（Please search for "PWM fans" on the R4S WiKi page for details)
• Improved stability on first boot (previous version, bpfilter error occurred in some cases on first boot)

17.21 2021-03-11

17.21.1 FriendlyWrt：

• Update FriendlyWrt's kernel to 5.10

17.22 2020-12-24

17.22.1 FriendlyWrt:

• FriendlyWrt has been updated to the official stable version 19.07.5

17.23 2020-12-17

17.23.1 FriendlyWrt:

1) FriendlyWrt provides two versions, using 4.19 kernel and 5.4 kernel, 5.4 is for R4S, other models please use 4.19 version
2) Improve the compatibility of the software package

17.23.2 FriendlyCore/FriendlyDesktop:

Update wiringPi to support more pins

17.24 2020-10-27

• Add new OS: FriendlyCore 20.04：

1) Linux kernel version: 4.19.111
2) Base on Ubuntu 20.04, keep the original features of FriendlyCore such as Qt5, OpenCV, WiringPi, etc. ffmpeg/mpv is not currently supported
3) U-Boot version: 2017.09
4) Integrate Rockchip's latest GPU, video codec, and Camera support

17.25 2020-09-27

17.25.1 Android 10:

• Add Supported for A/B (Seamless) System Update

17.26 2020-09-16

• Android 10：

1) Update SDK to Rockchip android-10.0-mid-rkr9
2) HDMI enable more resolution options
3) Fix the problem of no display on DisplayPort
4) Update the Bluetooth firmware to fix the issue that the NanoPi M4B cannot enable Bluetooth
5) Fix the logo display issue

• FriendlyCore/FriendlyDesktop：

1) Update the Bluetooth firmware and fix the issue that the Bluetooth firmware was not successfully loaded
2) Update bcmdhd driver to 1.579.77.41.22
3) Fixed the issue that the permissions of the /tmp/ directory were modified to read-only

17.27 2020-08-17

1) Optimized the steps and stability of installing the system through typc-c. AndroidTool and configuration files are preset for each system's compressed package, and there is no need to manually load files (Note: When changing the OS type in EMMC, you still need to wipe In addition to Flash, then burn the new OS);
2) Fixed the issue that the FriendlyWrt serial port could not be logged in;

17.28 2020-07-10

• Android 10：

1) Enable HDMI IN audio input and headphone port audio output by default for SOM-RK3399
2) Added support for 2 USB cameras to work together, Camera application can switch the front/rear camera preview
3) Pre-installed browser Chrome and input method Gboard

17.29 2020-06-23

• Add new OS: Android 10, the main features are as follows:

1) base on android-10.0-mid-rkr8：
- AOSP: android-10.0.0_r32
- Linux version 4.19.111
- U-Boot 2017.09
2) Support MIPI-CSI camera and USB camera
3) Support HDMI IN video input
4) Built-in Google Play
5) Built-in Lightning Browser
6) Enabled dynamic partitions
7) Built-in FriendlyThings demo
8) Built-in Quectel EC20 driver
9) Support RC-100 infrared remote control
10) Provides Settings to automatically hide navigation bars
11) Update tools:AndroidTool_Release_v2.71.zip,Linux_Upgrade_Tool_v1.49.zip

• Android8：

Provides Settings to automatically hide navigation bars

17.30 2020-03-24

1) Update Android8.1_SDK to Rockchip official version v8.32_20200218
2) Upgrade OpenCV to 4.2
3) Upgrade OpenWrt to 19.07.1
4) DDR loader updated to 1.24, support multiple frequency set points
5) Improved camera driver stability
6) Optimization of kernel stability

17.31 2019-12-27

• FriendlyCore/FriendlyDesktop：

1) Pre-installed wiringPi for python3, non-root users can access hardware resources such as gpio
2) Fixed virtual env permissions for pi user
3) Fixed /tmp directory permissions
4) Updated kernel configuration, improved docker compatibility

• FriendlyWrt：

Upgrade to OpenWrt r19-snapshot 64bit, support Docker CE

• eflasher：

1) Supports flashing only some files, such as updating only the kernel and uboot in emmc
2) Added gui option to disable overlay filesystem
3) Add command line parameters to achieve one-click installation without interaction
4) Fix the issue that the same mac address will appear on different devices after backup and restore image
5) UI interface can now be configured with title, hide interface menus and buttons

17.32 2019-09-26

• FriendlyCore/FriendlyDesktop：

Fix Qt5 demo touch screen related issue

17.33 2019-09-03

• Android 8.1：

1) Upgrade Android8.1_SDK to Rockchip v8.20_20190801 (Kernel: 4.4.167)
2) Increase the recording volume by 15dB
3) Fixed an issue where some HDMI display scales were not displayed correctly
4) USB Host: Enable DWC3's AutoRetry feature to improve the stability of some USB3.0 industrial cameras

• FriendlyCore/FriendlyDesktop：

1) Merge the official kernel update and upgrade the kernel to 4.4.179
2) USB Host: Enable DWC3's AutoRetry feature to improve the stability of some USB3.0 industrial cameras
3) Fixed HDMI IN issue

• Buildroot：

1) Upgrade Buildroot's version to Rockchip_v2.2.0_20190628
2) Merge the official kernel update and upgrade the kernel to 4.4.179
3) Fix bluetooth issue

17.34 2019-07-18

• FriendlyCore/FriendlyDesktop/Lubuntu：

1) Modify SDIO's maximum frequency to 150M to improve Wi-Fi performance
2) Fixed some unrecognized problems with NVMe M.2 SSDs, improving compatibility

• Android 8

1) Modify SDIO's maximum frequency to 150M to improve Wi-Fi performance
2) Bluetooth BLE enabled

17.35 2019-06-25

Linux(Ubuntu 16.04/18.04) uses OverlayFS to enhance filesystem stability.

17.36 2019-05-23

• Ubuntu 18.04(FriendlyCore, FriendlyDesktop)：

1) Fix the Pulseaudio issue
2) Fix the Bluetooth issue

17.37 2019-05-11

• Android 8.1:

1) Added support for PWM fan, support fan speed control
2) Add SSD support (Note: SSD partition needs to be ext4 format)

• FriendlyCore, FriendlyDesktop:

1) Kernel version updated to v4.4.167
2) the isp driver of the camera is upgraded from cif_isp10 to rk_isp1, supporting dual mipi cameras to work at the same time
3) OpenCV is upgraded to the latest version 4.1, supporting dual mipi camera and USB camera (logitech C920)
4) 4G network support is added to the Linux system (module: Quectel EC20)
5) Add Aanopc-t4 PWM fan support

• EFlasher system:

1) Reduced file system size
2) The network configuration is changed from DHCP to static IP address (192.168.1.231)

17.38 2019-03-08

• Add Buildroot project：

Add Buildroot Linux system, based on Rockchip original RK3399 Linux SDK, project open source, please refer to the details：Buildroot

• Android 8.1 update is as follows:

1) Optimized LCD and HDMI screen rotation settings, support for command line operations (command: wm rotation 90)
2) Fix the problem that the microphone cannot sound after forcing the audio output to the headphones

• FriendlyCore, FriendlyDesktop, Lubuntu is updated as follows:

1) Kernel version updated to v4.4.154
2) Docker support
3) Kernel configuration items are optimized to enable more features and device drivers
4) Fixed an issue where USB WiFi could not be used
5) Fix the stability problem of ISP camera

17.39 2018-12-19

• Android 8.1 update is as follows:

1) Update the AOSP source version to Android8.1-SDK v5.00-20181109
2) Add HDMI resolution and HDMI overscan setting UI
3) Add audio output settings, you can set the default output to headphones or HDMI
4) Add OV13850 and wide dynamic OV4689 camera support

• FriendlyCore is updated as follows:

1) Added OV13850 and wide dynamic OV4689 camera support
2) Added ffmpeg support, provides static libraries and header files, supports 4K hardware decoding (does not support hardware encoding)
3) Added mpv player, supports 4K hardware decoding

• FriendlyDesktop is updated as follows:

1) Added OV13850 and wide dynamic OV4689 camera support
2) Add Chrome-browser browser, support web page 1080P hardware decoding, support WebGL
3) Added ffmpeg support, provides static libraries and header files, supports 4K hardware decoding (does not support hardware encoding)
4) Fix the volume adjustment Issue
5) Set the audio output channel to HDMI by default (can be modified by /etc/pulse/default.pa)
6) Optimize the local player, associated with the mp4 file
7) Automatically enable swap partitioning for NEO4
8) Fix the issue of hostapd related issues
9) Adjust DPMS settings, turn off automatic sleep by default

• Lubuntu updated as follows:

1) Added OV13850 and wide dynamic OV4689 camera support
2) Add Chrome-browser browser, support web page 1080P hardware decoding, support WebGL
3) Set the audio output channel to HDMI by default (can be modified by /etc/asound.conf)
4) Optimize the local hard disk player, associated with the local mp4 file, double-click the local video to start the local hard disk player playback (only mp4 files are supported)
5) Fixed some issues regarding the package error reported in the previous version
6) Adjust DPMS settings, turn off automatic sleep by default

17.40 2018-11-12

• Android 8.1 update is as follows:

1) Add support for USB-C display
2) Add support for 4G network, the model number of the support module is: Quectel EC20
3) Add Android hardware access library FriendlyThing for programming various hardware resources under Android, such as Uart, SPI, I2C, GPIO, etc.
4) Optimize kernel configuration to improve PCIe performance, and connect NVME SSD will have a large performance improvement
5) Integrate the Google Play app store
6) Improve the underlying support of the camera so that it can automatically adapt to vertical screen (HD702E) and landscape (HDMI)
7) Fix the problem that the partition table is abnormal when Android8 is connected to NVME SSD and Android8 cannot be started.

• Android 7.1 update is as follows:

1) Add support for 4G network, the model number of the support module is: Quectel EC20
2) Add Android hardware access library FriendlyThing for programming various hardware resources under Android, such as Uart, SPI, I2C, GPIO, etc.
3) Optimize kernel configuration to improve PCIe performance, and connect NVME SSD will have a large performance improvement
4) Improve the underlying support of the camera so that it can automatically adapt to vertical screen (HD702E) and landscape (HDMI)
5) Fix the problem that the partition table is abnormal when Android8 is connected to NVME SSD and Android8 cannot be started.

• FriendlyCore and FriendlyDesktop are updated as follows:

1) Added support for OV13850 camera, provides gsteamer plugin to support ISP
2) Add WiringPi support for C language programming to access hardware resources such as GPIO
3) Added WiringPi-Python support for Python programming access to hardware resources such as GPIO
4) Optimize kernel configuration to improve PCIe performance, and connect NVME SSD will have a large performance improvement

17.41 2018-09-21

• Added support for an eDP screen
• Linux has enabled PCI-E to Sata function (AHCI SATA support)
• SquashFS under Linux enables LZO/XZ/ZSTD compression support

17.42 2018-09-05

• Add new OS: Android 8.1, the main features are as follows:

1) Support 2 CAM1320 (OV13850) at the same time, you can choose to switch between before and after camera use
2) Support USB camera (1 way, can not be used simultaneously with CAM1320)
3) Support AndroidNN GPU acceleration solution, which provides general acceleration support for AI related applications developed with AndroidNN API
4) Integrate the Tensorflow Lite item identification demo provided by Rockchip: TfLiteCameraDemo (connect CAM1320 or USB camera before starting)
5) Integrated Lightning is the default browser application (Note: Android official does not provide Browser application by default)
6) Support RC-100 infrared remote control, support pull-down notification bar, screen capture
7) Support Android full disk encryption function, system partition has Verity enabled, when using adb, adb root; adb disable-verity command disable Verity
8) Support MTP function, after connecting Type-C, you can enter Settings -> Connected devices -> USB to select the corresponding function
9) Upgrade the kernel version to 4.4.126
10) Update the AOSP source to the version android-8.1.0_r41 and update the August security patch

• FriendlyCore adds Qt dual camera sample program: the example is located in /opt/dual-camera directory, run by run.sh (two USB cameras must be connected before starting, it is recommended to use Logitech C270 or Logitech C922 camera)
  
• FriendlyDesktop defaults to HDMI resolution of 1080P