1. Buildroot manual

1.1. Desktop application

The officially released Buildroot firmware supports the Wayland desktop environment and some Qt applications by default, as shown below:

1.1.1. multivideoplayer

The multivideoplayer is used to test the device’s multi-channel video playback ability, display ability and hardware decoding ability.

1.1.2. qfm

The qfm is a file browser.

1.1.3. qplayer

The qplayer is a multi-function player, it can play videos, audios and display pictures.

1.1.4. qcamera

The qcamera is a camera application, can take photos and record videos.

Launch the qcamera when device is connected to a camera, qcamera will automatically display the camera pictures. And the buttons on the right side are:

• Image Mode: Now is image mode, click to change to the video record mode.

• Capture: capture image，it will change to Record button when in video record mode.

• Exit: close the application.

1.1.5. qsetting

The qsetting is a system setting tool, you can config WiFi connection, bluetooth connection and perform factory reset, firmware update in it.

1.2. User and password

• User: root

• Password: firefly

1.3. Ethernet configuration

Buildroot’s network configuration needs to use the /etc/network/interfaces configuration file. After the configuration is complete, run /etc/init.d/S40network restart to restart the network. Manual debugging can directly use ifdown -a and ifup -a to restart the network.

1.3.1. Common configuration

Configuration file example: The following configuration file sets the eth0 network card to a dynamic IP address and eth1 to a static IP address

Note: The file format of /etc/network/interfaces is strict. If you encounter Error: either "local" is duplicate, or "/24" is a garbage., it is very likely that there is one more space in the configuration file.

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp

auto eth1
iface eth1 inet static
address 168.168.110.137
netmask 255.255.0.0
broadcast 168.168.1.255
gateway 168.168.0.1

(1) inet static: Define a static IP address. The supported options are:

address address
        Address (dotted quad/netmask) required

netmask mask
        Netmask (dotted quad or number of bits) deprecated

broadcast broadcast_address
        Broadcast address (dotted quad, + or -) deprecated. Default value: "+"

metric metric
        Routing metric for default gateway (integer)

gateway address
        Default gateway (dotted quad)

pointopoint address
        Address of other end point (dotted quad). Note the spelling of "point-to".

hwaddress address
        Link local address or "random".

mtu size
        MTU size

scope Address validity scope. Possible values: global, link, host

(2) inet dhcp: Obtain an IP address through the DHCP protocol. The supported options are:

hostname hostname
        Hostname to be requested (pump, dhcpcd, udhcpc)

metric metric
        Metric for added routes (dhclient)

leasehours leasehours
        Preferred lease time in hours (pump)

leasetime leasetime
        Preferred lease time in seconds (dhcpcd)

vendor vendor
        Vendor class identifier (dhcpcd)

client client
        Client identifier (dhcpcd)

hwaddress address
        Hardware address.

(3) inet manual: No IP address is defined for the interface. Typically used by an interface that is a member of a bridge or aggregation, an interface that needs to operate in promiscuous mode (for example, port mirroring or network TAP), or an interface that has a VLAN device configured on it. This is one way to keep the interface without an IP address. The supported options are:

hwaddress address
        Link local address or "random".

mtu size
        MTU size

1.3.2. advanced settings

/etc/network/interfaces supports setting to run Linux command line commands when the network card is shut down/started. Since /etc/network/interfaces supports relatively limited functionality, this can be very helpful when configuring network configurations such as static routes, default routes, etc.

Supported optional options are: pre-up, up, post-up, pre-down, down, post-down, after these options, add the command line.

pre-up    : Action before network card is up
up        : Action when network card is up
post-up	  : Action after network card is up
pre-down  : Action before network card is down
down      : Action when network card is down
post-down : Action after network card is down

Configuration example: configure a static route for the eth1 network card

auto eth1
iface eth1 inet static
address 192.168.3.1
netmask 255.255.255.0
broadcast 192.168.3.255
post-up ip route add 192.168.4.0/24 via 192.168.3.2 dev $IFACE

Configuration example: create a bridge, bind eth0 and eth1 to the bridge, and use it as a LAN port

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet manual
pre-up ifconfig $IFACE up
post-down ifconfig $IFACE down

auto eth1
iface eth1 inet manual
pre-up ifconfig $IFACE up
post-down ifconfig $IFACE down

auto br0
iface br0 inet static
address 192.168.2.1
netmask 255.255.255.0
broadcast 192.168.2.255
pre-up brctl addbr $IFACE
pre-up brctl addif $IFACE eth0
pre-up brctl addif $IFACE eth1
bridge_ports eth0 eth1
post-down brctl delif $IFACE eth0
post-down brctl delif $IFACE eth1
post-down ifconfig $IFACE down
post-down brctl delbr $IFACE

1.4. WiFi connection

1.4.1. Modify the configuration file

1.4.1.1. Method 1

Configuration via the qsetting QT application.

1.4.1.2. Method 2

Modify the following files:

vi /data/cfg/wpa_supplicant.conf
ctrl_interface=/var/run/wpa_supplicant
ap_scan=1

Add the following configuration items

network={
ssid="WiFi-AP" // WiFi name
psk="12345678" // WiFi password
key_mgmt=WPA-PSK // encryption method
# key_mgmt=NONE // no encryption
}

Start the wpa_supplicant process

wpa_supplicant -B -i wlan0 -c /data/cfg/wpa_supplicant.conf

1.4.2. Temporary modification method

Modify the following files:

vi /data/cfg/wpa_supplicant.conf
ctrl_interface=/var/run/wpa_supplicant
ap_scan=1

Start the wpa_supplicant process:

wpa_supplicant -B -i wlan0 -c /data/cfg/wpa_supplicant.conf

1.4.2.1. Configure WiFi via wpa_cli

Common commands:

wpa_cli -i wlan0 scan // Search for nearby wifi networks
wpa_cli -i wlan0 scan_result // print search wifi network
wpa_cli -i wlan0 add_network // add a network connection

If the encryption method to connect is [WPA-PSK-CCMP+TKIP][WPA2-PSK-CCMP+TKIP][ESS] (wpa encryption), the wifi name is name, and the wifi password is: psk. The operation is as follows:

wpa_cli -i wlan0 set_network 0 ssid '"name"'
wpa_cli -i wlan0 set_network 0 psk '"psk"'
wpa_cli -i wlan0 set_network 0 key_mgmt WPA-PSK
wpa_cli -i wlan0 enable_network 0 //Enable WiFi

If the connection encryption method is [WEP][ESS] (wep encryption), the wifi name is name, and the wifi password is psk. The operation is as follows:

wpa_cli -i wlan0 set_network 0 ssid '"name"'
wpa_cli -i wlan0 set_network 0 key_mgmt NONE
wpa_cli -i wlan0 set_network 0 wep_key0 '"psk"'
wpa_cli -i wlan0 enable_network 0

If the connection encryption method is [ESS] (no encryption), the wifi name is name. The operation is as follows:

wpa_cli -i wlan0 set_network 0 ssid '"name"'
wpa_cli -i wlan0 set_network 0 key_mgmt NONE
wpa_cli -i wlan0 enable_network 0

Enable to save WIFI connection information

wpa_cli -i wlan0 set update_config 1

Save WIFI connection information

wpa_cli -i wlan0 save_config

connect an existing connection

wpa_cli -i wlan0 list_network // List all saved connections
wpa_cli -i wlan0 select_network 0 // connect to the first saved connection
wpa_cli -i wlan0 enable_network 0 // enable the first saved connection

Turn off WiFi

ifconfig wlan0 down

1.5. Audio/Video playback

# Play wav
aplay test.wav
gstwavplay.sh test.wav

# Play mp3
mp3play.sh test.mp3
gstmp3play.sh test.mp3

# Play mp4
gstmp4play.sh test.mp4
gstvideoplay.sh test.mp4

1.6. SSH

The officially released SDK has ssh enabled by default, the user is “root”, and the password is “firefly”. If you do not need to modify the user login password, you can skip this chapter.

1.6.1. Modification method

• Enable SSH related options

  • openssh

  BR2_PACKAGE_OPENSSH=y
  

  • Configure the login account root and password

  BR2_TARGET_ENABLE_ROOT_LOGIN=y
  BR2_TARGET_GENERIC_ROOT_PASSWD="firefly"
  

• Modify configuration files

  • Modify the /etc/ssh/sshd_config file in the board

  PermitRootLogin yes
  

1.7. External storage device

Buildroot supports automatic mounting of external storage devices:

• U disk mount path: /udisk

• TF card mounting path: /sdcard

1.8. Factory Reset

**Note: This factory setting means returning to the original state of the device after the last firmware upgrade. **

1.8.1. method 1

Configure through the qsetting QT application and click the “Factory Reset” function option to operate.

1.8.2. Method 2

via the update command

update
# or
update factory / update reset

1.9. Firmware local upgrade

Buildroot supports upgrading firmware from external storage devices. The following is the upgrade process description.For how to compile the Buildroot firmware, please refer to the Compile Buildroot firmware page of the corresponding board wiki.

1.9.1. Make upgrade firmware

Follow the normal firmware compilation process to make the firmware for upgrade.

To upgrade firmware, it is not necessary to upgrade all partitions. You can modify the package-file file, comment out the partitions that do not need to be upgraded, or change to RESERVED, which can reduce the size of the upgraded firmware.

For example, modify the file tools/linux/Linux_Pack_Firmware/rockdev/rk356x-package-file, change the relative path of rootfs to RESERVED, so that the root filesystem will not be packaged, that is, the root filesystem partition will not be upgraded.

（1）modify the file tools/linux/Linux_Pack_Firmware/rockdev/package-file.

For example, change the relative path of rootfs to RESERVED, so that the root filesystem will not be packaged, that is, the root filesystem partition will not be upgraded.

# name          relative path
#
#hwdef          hwdef
package-file    package-file
bootloader      image/miniloaderall.bin
parameter       image/parameter.txt
trust           image/trust.img
uboot           image/uboot.img
misc            image/misc.img
boot            image/boot.img
recovery        image/recovery.img
rootfs          RESERVED
oem             image/oem.img
userdata:grow   image/userdata.img
backup          RESERVED

（2）compile

./build.sh updateimg

Copy the prepared upgrade firmware to the U disk, TF card, or the /userdata/ directory of the device, and rename it to update.img.

Note: If the upgrade firmware is placed in the /userdata/ directory of the device, do not package userdata.img, and change image/userdata.img to RESERVED.

1.9.2. Upgrade

1.9.2.1. method 1

Configuration via the qsetting QT application. Click the “Update” function option to operate.

1.9.2.2. Method 2

via the update command.

# U disk
update ota /udisk/update.img
# TF card
update ota /sdcard/update.img
# /userdata/
update ota /userdata/update.img

Wait for the upgrade to complete. After the upgrade is successful, the device will reboot into the system.

1.10. Weston

We can customize the display by configuring Weston, some of the settings are explained below.

1.10.1. Status Bar

Weston supports setting the background color and position of the status bar in the shell section of the weston.ini configuration file, as well as setting quick launch programs in the launcher section, such as:

# /etc/xdg/weston/weston.ini

[shell]
# The color format is ARGB8888
panel-color=0xff002244
# top|bottom|left|right|none
panel-position=bottom

[launcher]
icon=/usr/share/weston/terminal.png
path=/usr/bin/weston-terminal

[launcher]
# Icon path
icon=/usr/share/weston/icon_flower.png
# Quick start command
path=/usr/bin/qsetting

1.10.2. Background

Weston supports setting background patterns and colors in the shell section of the weston.ini configuration file, such as:

# /etc/xdg/weston/weston.ini

[shell]
# Background pattern (wallpaper) absolute path
background-image=/usr/share/weston/background.png
# scale|scale-crop|tile
background-type=scale
# The color format is ARGB8888, which will take effect when the background pattern is not set
background-color=0xff002244

1.10.3. Standby and lock screen

Weston’s timeout standby time can be configured in the startup parameters or in the core section of weston.ini, such as:

# /etc/init.d/S50launcher
     start)
         ...
         # 0 is to prohibit standby, the unit is second
         weston --tty=2 -B=drm-backend.so --idle-time=0&

or:

# /etc/xdg/weston/weston.ini

[core]
# Set to enter the standby state after 5 seconds of inactivity
idle-time=5

1.10.4. Display color format

The current default display format of Weston in Buildroot SDK is ARGB8888. For some low-performance platforms, it can be configured as RGB565 in the core section of weston.ini, such as:

# /etc/xdg/weston/weston.ini

[core]
# xrgb8888|rgb565|xrgb2101010
gbm-format=rgb565

You can also configure the display format of each screen separately in the output section of weston.ini, such as:

# /etc/xdg/weston/weston.ini

[output]
# The name of output can be viewed /sys/class/drm/card0-name
name=LVDS-1
# xrgb8888|rgb565|xrgb2101010
gbm-format=rgb565

1.10.5. Screen orientation

Weston’s screen display direction can be configured in the output section of weston.ini, such as:

# /etc/xdg/weston/weston.ini

[output]
name=LVDS-1
# normal|90|180|270|flipped|flipped-90|flipped-180|flipped-270
transform=180

If you need to dynamically configure the screen orientation, you can use a dynamic configuration file, such as:

echo "output:all:rotate90"> /tmp/.weston_drm.conf # All screens are rotated 90 degrees
echo "output:eDP-1:rotate180"> /tmp/.weston_drm.conf # eDP-1 rotate 180 degrees

1.10.6. Resolution and scaling

The screen resolution and scaling of Weston can be configured in the output section of weston.ini, such as:

# /etc/xdg/weston/weston.ini

[output]
name=HDMI-A-1
# Need to be an effective resolution supported by the screen
mode=1920x1080
# Must be an integer multiple
scale=2

If you need to dynamically configure resolution and scaling, you can use dynamic configuration files, such as:

echo "output:HDMI-A-1:mode=800x600"> /tmp/.weston_drm.conf # Modify the resolution of HDMI-A-1 to 800x600

You need to rely on RGA acceleration when scaling in this way.

1.10.7. Freeze screen

When Weston was started, there was a black screen for a short period switching between the boot logo and the UI display. If you need to prevent a black screen, you can temporarily freeze the Weston screen content through the following dynamic configuration file methods:

# /etc/init.d/S50launcher
     start)
         ...
         export WESTON_FREEZE_DISPLAY=/tmp/.weston_freeze # Set the path of the special configuration file
         touch /tmp/.weston_freeze # Freeze display
         weston --tty=2 -B=drm-backend.so --idle-time=0&
         ...
         sleep 1 && rm /tmp/.weston_freeze& # Thaw in 1 second

1.10.8. Multi-screen

The Weston of the Buildroot SDK supports functions such as multi-screen same-different display and hot-plugging. The distinction between different display screens is based on the drm name (obtained via /sys/class/drm/card0-name), and the relevant configuration is set through environment variables, such as:

# /etc/init.d/S50launcher

    start)
        ...
        export WESTON_DRM_PRIMARY=HDMI-A-1 # Specify the main display as HDMI-A-1
        export WESTON_DRM_MIRROR=1 # Use mirror mode (multiple screens at the same display), if you don’t set this environment variable, it will be a different display
        export WESTON_DRM_KEEP_RATIO=1 # The zoom maintains the aspect ratio in the mirror mode. If this variable is not set, the full screen is forced
        export WESTON_DRM_PREFER_EXTERNAL=1 # The built-in display is automatically turned off when the external display is connected
        export WESTON_DRM_PREFER_EXTERNAL_DUAL=1 # When the external display is connected, the first external display is the main display by default
        weston --tty=2 -B=drm-backend.so --idle-time=0&

When zooming the display content in the mirror mode, you need to rely on RGA acceleration.

At the same time, it is also supported to individually disable specific screens in the output section of weston.ini:

# /etc/xdg/weston/weston.ini

[output]
name=LVDS-1
mode=off
# off|current|preferred|<WIDTHxHEIGHT@RATE>

1.10.9. Input device related

Weston service requires at least one input device by default. If there is no input device, special settings in the core section of weston.ini are required:

# /etc/xdg/weston/weston.ini

[core]
require-input=false