Firefly version

View the firmware version  In the Settings  Settings-->About
tablet-->Firefly version  for example:  ROC-RK3399-PC+
HDMI+DP(Android)
rk3399_roc_pc_plus/industry-71/V1.2.2008101849/98c828d3a1d2

Open developer options

Settings-->About tablet-->Build number

Click Build number at least 7 times

Use of ADB

Connect the device

USB way

The host connects to the device via USB. For details on how to
connect, please refer to the

WiKi Tutorial

 of the device.

USB Type A interface  Enable USB connection  Android7.1
Settings-->USB-->Connect to PC  Android10/Android11
Settings-->Connected devices-->Connect to PC

USB Type C interface (enabled by default)

Network way

The host connects to the device through the network (the host and the
device are in the same LAN)

Open network ADB

View the IP address of the device  Settings-->About
tablet-->Status->IP address

Connect to device via IP address  adb connect device_ip_address

Common commands

Query device  adb devices

Stop adb server  adb kill-server

Install the app  adb install path_to_apk

Copy files to device  adb push local remote

Copy files from device  adb pull remote local

Issue shell commands  adb [-d |-e | -s serial_number] shell
shell_command

Log

Last Log

In the "/sys/fs/pstore" directory of the device:

console-ramoops-0: last_log The kernel log started last time, but only
the logs with higher priority than the default log level are saved

pmsg-ramoops-0: Last user space log, android log

Log is automatically saved

Way one (<font color=#FF0000>recommended use</font>)

Open "Developer Options"

Enable automatic log saving  Android7.1  Settings-->Developer
options-->Android bug collector  Android10/Android11/Android12
Settings-->System-->Developer options-->Android LogSave

reboot device

There are log related files in the /data/logs directory of the device
(**Android 10 and above: **/data/vendor/logs)  android: system logcat
kernel: kernel kmsg

Way two

Open "Developer Options"

Enable Enable logging to save  Settings-->Developer options-->Enable
logging to save

reboot device

There are log related files in the /data/media/0/.LOGSAVE directory of
the device  xxxx_kmsg.log: kernel kmsg  xxxx_logcat.log: system logcat

NOTE:

 Only supports Android 7.1

Way three

Open "Developer Options"

Enable Android bug collector  Settings-->Developer options-->Android
bug collector

reboot device

There are log related files in the /data/media/0/rk_logs directory of
the device  COPY-COMPLETEB means log has been copied  anr means ANR
file  bugreport.log means the bugreport file  logs means logcat, kmsg
after each boot  pstore means last_log  tombstones means tombstones
file

NOTE:

 Only supports Android 7.1

Android system signature file

Cloud storage

Android7.1 and above  Download here

Android5.1  Download here

Timer switch

The device must have an RTC chip  RK808  HYM8563

Equipment is always powered

You can directly use cat and echo to operate the interface under
"/sys/class/rtc/rtc0".

Set boot time

For example, set it to boot after 120 seconds

   # Turn on regularly after 120 seconds 
   echo +120 >  /sys/class/rtc/rtc0/wakealarm
   # View boot time 
   cat /sys/class/rtc/rtc0/wakealarm
   # Shut down 
   reboot -p

Use of NPU

Turn on the touch effect

Open "Developer Options"

Enable Show taps  Android7.1<br> Settings-->Developer options-->Show
taps  Android10/Android11/Android<br> Settings-->System-->Developer
options-->Show taps

Enable Pointer location  Android7.1<br> Settings-->Developer
options-->Pointer location  Android10/Android11/Android12<br>
Settings-->System-->Developer options-->Pointer location

Rockchip Encoder/Decoder

MediaCodec

Android's

MediaCodec

 calls the Rockchip Encoder/Decoder by default.  If you need native
api, you can use MPP.

MPP

Media Process Platform (MPP) provided by Rockchip is a general media
processing software platform for Rockchip chip series. For
applications the MPP platform shields the complex lower-level
processing related to chips. Its purpose is to shield the differences
between different chips and provide a unified media process interface
(MPI) to users.

Documents: SDK/RKDocs/common/MPP/

Source Code: https://github.com/rockchip-linux/mpp