bananapi-zero-ubuntu-base-minimal

BananaPi M2 Zero - Ubuntu Xenial Base Minimal Image (Experimental) - U-Boot 2017.09 / Kernel 4.19.y (mainline - stable)

• Introduction
• Kernel History
• Bluetooth
• Working with Cameras
• Releases

The Image comes with the minimum packages but you can install a full Desktop on top of this, see how at the end.

Introduction

This is a WiP, a bare minimum firmware image (CLI - command line interface) with basic configurations. Kernel used is Mainline kernel 4.17.y / 4.18.y / 4.20.y / 5.3.y / 5.6.y / 5.7.y / 5.11.y with some patches applied.
The idea behind this firmware is to have a very basic sd card image and add packages to your need.
Kernel 5.7.10 / 5.11.10 has support for OV5640.

Kernel history

• v1 is Kernel 4.15.y

• v2 is Kernel 4.17.y

  For convenience, an 8GB SD CARD Image is at https://mega.nz/#!obIAVQiA!G0CCABkLunCcG8hEqMf7NfjTBK1jgMytt2f0VdtOl08

  Use 7zip to unzip it and flash it with etcher or win32imagewriter (Win32DiskImager)

• v2 stable kernel 4.17.12 update

    sudo dpkg -i linux-image-4.17.12-m2z_1.0-5.deb

and then:

    sync && sudo shutdown -h now

power cicle the board

• v3 stable kernel 4.18.4 upgrade

    sudo dpkg -i linux-image-4.18.4-m2z_1.0-7.deb

and then:

    sync && sudo shutdown -h now

power cicle the board

• v4 stable kernel 4.18.8 upgrade

Before upgrade, get rid of old kernel image not in use and check available space in /boot

    df -lh
    Filesystem      Size  Used Avail Use% Mounted on
    /dev/mmcblk0p2   15G  631M   13G   5% /
    devtmpfs        183M     0  183M   0% /dev
    tmpfs           248M     0  248M   0% /dev/shm
    tmpfs           248M   11M  237M   5% /run
    tmpfs           5.0M     0  5.0M   0% /run/lock
    tmpfs           248M     0  248M   0% /sys/fs/cgroup
    /dev/mmcblk0p1   93M   64M   23M  74% /boot

Make sure you have enough free space left, if not, issue in shell:

    sudo dpkg -l | grep linux-image
    ii  linux-image-4.17.12-m2z           1.0-5                                      armhf        Linux kernel 4.17.12-m2z
    ii  linux-image-4.17.8-m2z            1.0-1                                      armhf        Linux kernel 4.17.8-m2z
    ii  linux-image-4.17.9-m2z            1.0-2                                      armhf        Linux kernel 4.17.9-m2z
    ii  linux-image-4.18.6-m2z-otg-gadget 1.0-11                                     armhf        Linux kernel 4.18.6-m2z-otg-gadget

and check the current kernel you are running:

    uname -r 
    4.18.6-m2z-otg-gadget

so it is safe to get rid of unused kernel and free some space for the new one you want to install:

    sudo dpkg -r linux-image-4.17.12-m2z
    (Reading database ... 35990 files and directories currently installed.)
    Removing linux-image-4.17.12-m2z (1.0-5) ...

and now install the latest kernel:

    sudo dpkg -i linux-image-4.18.8-m2z-otg-gadget_1.0-12.deb
    Selecting previously unselected package linux-image-4.18.8-m2z-otg-gadget.
    (Reading database ... 33740 files and directories currently installed.)
    Preparing to unpack linux-image-4.18.8-m2z-otg-gadget_1.0-12.deb ...
    INFO: Updating Kernel 4.18.6-m2z-otg-gadget to 4.18.8-m2z-otg-gadget
    INFO: Updating...
    Unpacking linux-image-4.18.8-m2z-otg-gadget (1.0-12) ...
    Setting up linux-image-4.18.8-m2z-otg-gadget (1.0-12) ...
    OK: Kernel upgrade success! Please reboot with: sync && sudo reboot

and then:

    sync && sudo reboot 

or better

    sync && sudo shutdown -h now

power cicle the board and check kernel version again:

    uname -r 
    4.18.8-m2z-otg-gadget

• v5 mailine kernel 4.19.0 upgrade

    sudo dpkg -i linux-image-4.19.0-m2z-otg-gadget_1.0-13.deb
    sync && sudo reboot 

• v6 mailine kernel 4.19.1 (stable) upgrade

    sudo dpkg -i linux-image-4.19.1-m2z-otg-gadget_1.0-14.deb
    sync && sudo reboot 

• v7 mailine kernel 4.20.0-rc2 (mainline) upgrade

    sudo dpkg -i linux-image-4.20.0-rc2-m2z-otg-gadget_1.0-15.deb
    sync && sudo reboot 

rebuild bpi-m2z_boot.scr with:

    edit bpi-m2-zero_boot.cmd and change:
    setenv extra "no_console_suspend consoleblank=0 drm_leak_fbdev_smem=1"
    setenv bootargs "console=ttyS0,115200 earlyprintk rootfstype=ext4 root=/dev/mmcblk0p2 rw rootwait fsck.repair=${fsck.repair} panic=10 ${extra}"
    bootz ${kernel_addr} ${ramdisk_addr}:${ramdisk_size} ${dtb_addr}

rebuild with:

    sudo mkimage -C none -A arm -T script -d bpi-m2-zero_boot.cmd bpi-m2-zero_boot.scr

• v8 mailine kernel 4.20.0-rc3 (mainline) upgrade

    sudo dpkg -i linux-image-4.20.0-rc3-m2z-otg-gadget_1.0-16.deb
    sync && sudo reboot 

• v9 mailine kernel 4.19.5 (stable) upgrade

    sudo dpkg -i linux-image-4.19.5-m2z-otg-gadget_1.0-19.deb
    sync && sudo reboot 

• v10 mailine kernel 4.19.6 (stable) upgrade

deb file in Release v10, grab the file with:

    wget https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/download/v10/linux-image-4.19.6-m2z-otg-gadget_1.0-20.deb
    sudo dpkg -i linux-image-4.19.6-m2z-otg-gadget_1.0-20.deb
    sync && sudo reboot 

• v11 mailine kernel 4.19.12 (stable) upgrade

deb file in Release v11, grab the file with:

    wget https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/download/v11/linux-image-4.19.12-m2z-otg-gadget_1.0-21.deb
    sudo dpkg -i linux-image-4.19.12-m2z-otg-gadget_1.0-21.deb
    sync && sudo reboot 

• v12 mailine kernel 4.20.0 (experimental) upgrade

deb file in Release v12, grab the file with:

    wget https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/download/v12/linux-image-4.20.0-m2z-otg-gadget_1.0-22.deb
    sudo dpkg -i linux-image-4.20.0-m2z-otg-gadget_1.0-22.deb
    sync && sudo reboot 

• v13 mailine kernel 4.20.17-m2z (experimental) upgrade

        https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v13

Mainline stable Kernel 4.20.17 (Kodi)

This kernel is provided as a POC where you can build Kodi

Attention

The mali blobs used for the mali GBM are not compatible with the mali FBDEV
You are required to update the mali with the wayland mali to be able to use GBM

Mainline stable kernel 4.20.17 ready to build Kodi:

• Cedrus (VPU)
• Mali (GBM)
• hdmi-sound
• wifi + eth
• tools to test cedrus and gbm (pre-built)

To test mali GBM you can run kmscube
To test cedrus you can run v4l2-request-test

VPU test

Testing cedrus on mainline is quite simple, run the tests below:

cd v4l2-request-test
sudo ./v4l2-request-test -l -f 25 -P ed-mpeg2

or

sudo ./v4l2-request-test -l -f 25 -P caminandes-h265

Mali GBM test

To test mali GBM you need to setup the mali blobs provided by https://github.com/bootlin/mali-blobs

sudo ./kmscube

When you run the kmscube you will see a cube spinning

• Tools:

  https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v14

hdmi-sound

To be able to acess and output sound to HDMI you need to update the file /etc/asound.conf

pcm.!default {
    type plug
    slave {
    pcm "hw:1,0"
    }
}
ctl.!default {
   type hw
   card 1
} 

Reboot and test the HDMI sound:

sudo aplay /usr/share/sounds/alsa/Front_Left.wav

Check for the codecs:

cat /proc/asound/cards

 0 [Codec          ]: H3_Audio_Codec - H3 Audio Codec
              H3 Audio Codec
 1 [allwinnerhdmi  ]: allwinner_hdmi - allwinner,hdmi
              allwinner,hdmi

• v37 mailine kernel 5.7.6 (experimental) Ubuntu 19.10 EOAN

  • Add support for Camera.

  • CPU Temp throtling at 80C

Instructions:
https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v3.7

• v35 mailine kernel 5.6.13-server (experimental) Ubuntu 19.10 EOAN

Server edition with no HW acceleration ideal for embedded systems where you can build your server applications, kernels or install a small Desktop like LXDE.

Small footprint.

Fix: CPU Temp, DVFS, BT

• Instructions:

https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v3.6

• v34 mailine kernel 5.6.5-server (experimental) Ubuntu 19.10 EOAN

This is the ideal server like kernel where you can build your applications, kernels or install a small Desktop.
There is no HW accelerations but it is with a small footprint.

• Instructions:

https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v3.5

• v33 mailine kernel 5.6.5-r1 (experimental) Ubuntu 19.10 EOAN with GBM

This is kernel 5.6.5 with mali GBM instead of panfrost

https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v3.3

How to install the new kernel on EOAN only:

• download the deb file linux-image-5.6.5-r1_1.0-42.deb
• run in shell: sudo dpkg -i linux-image-5.6.5-r1_1.0-42.deb

you get similar output:

ubuntu@bpi-m2z:~$ sudo dpkg -i linux-image-5.6.5-r1_1.0-42.deb 
Selecting previously unselected package linux-image-5.6.5-r1.
(Reading database ... 56892 files and directories currently installed.)
Preparing to unpack linux-image-5.6.5-r1_1.0-42.deb ...
INFO: Updating Kernel 5.6.3 to 5.6.5-r1
INFO: Updating...
Unpacking linux-image-5.6.5-r1 (1.0-42) ...
Setting up linux-image-5.6.5-r1 (1.0-42) ...
OK: Kernel upgrade success! Please reboot with: sync && sudo reboot
ubuntu@bpi-m2z:~$ sync
ubuntu@bpi-m2z:~$ sudo reboot
Connection to 192.168.254.16 closed by remote host.
Connection to 192.168.254.16 closed.
alex@svn:/arm/ubuntu/friendlywrt-rk3328$ ssh ubuntu@192.168.254.16
ubuntu@192.168.254.16's password: 
Welcome to Ubuntu 19.10 (GNU/Linux 5.6.5-r1 armv7l)
 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage
Last login: Mon Apr 20 23:04:40 2020 from 192.168.254.253
ubuntu@bpi-m2z:~$ 

Checking for the Bluetooth:

ubuntu@bpi-m2z:~$ hciconfig
hci0:    Type: Primary  Bus: UART
    BD Address: CC:B8:A8:A9:E5:67  ACL MTU: 1021:8  SCO MTU: 64:1
    UP RUNNING PSCAN 
    RX bytes:2184 acl:0 sco:0 events:214 errors:0
    TX bytes:36815 acl:0 sco:0 commands:215 errors:0
ubuntu@bpi-m2z:~$ 

• v32 mailine kernel 5.6.0-rc5 (experimental) Ubuntu 19.10 EOAN

https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v3.2

Testing HDMI sound output:

• add user to audio group (no need for sudo while playing sound)

  sudo usermod -a -G audio ubuntu

• play some sounds

aplay -D pulse /usr/share/sounds/alsa/Front_Right.wav (sound output via pulse)
aplay -D sysdefault:CARD=1 /usr/share/sounds/alsa/Front_Right.wav (HDMI sound output)
aplay -D sysdefault:CARD=0 /usr/share/sounds/alsa/Front_Right.wav (sound output to analog)

• v31 mailine kernel 5.6.0-rc4 (experimental) Ubuntu 19.10 EOAN

https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v3.1

• Lima support (for testing)

• v30 mailine kernel 5.6.0-rc3 (experimental) Ubuntu 19.10 EOAN

• Lima support (testing)

Kernel Image: https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v3.0

• v29 mailine kernel 5.3.18 (experimental) Ubuntu 19.10 EOAN

Kernel Image: https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v2.9

• v25 mailine kernel 5.3.7 fbdev (experimental) Ubuntu 19.10 EOAN

Os Image: https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v2.5

Mainline stable kernel 5.3.7 with:

• Small footprint (hmm, ok, not so small, lots of packages installed)
• HDMI
• sound-hdmi
• Bluetooth (to be tested)
• cedrus
• Wifi
• Ethernet 100 MBits
• mali fbdev

• v24 mailine kernel 5.3.5 (experimental) Ubuntu 19.10 EOAN

OS Image: https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v2.4

Mainline stable kernel 5.3.5 with:

• Small footprint
• HDMI
• sound-hdmi
• Bluetooth (to be tested)
• cedrus
• Wifi
• Ethernet 100 MBits

• v21 mailine kernel 5.3.4 (experimental) upgrade

deb package: https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v2.3

Mainline stable kernel 5.3.4 with:

• HDMI
• sound-hdmi
• Bluetooth (issue with sound)

• cedrus

• v20 mailine kernel 5.3.1 (experimental) upgrade and fix

deb package: https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v2.2

Mainline stable kernel 5.3.1 with:

• HDMI (fix)
• sound-hdmi
• Bluetooth (fix)
• cedrus

Attention

If you aleady upgraded to the buggy kernel 5.3.1 you need to downgrade or create a clean installation.

• v19 mailine kernel 5.3.1 (experimental) upgrade

deb package: https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v2.1

• v18 mailine kernel 5.3.0-rc7 (experimental) upgrade

  deb package:

  https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v1.8

Mainline Kernel 5.3.0-rc7

This is mainline Kernel 5.3.0-rc7.

Bootlo: https://gist.github.com/avafinger/9f6bee00e17b1f1d5d120e8b048eb40f
Install the new Kernel (tested): https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v1.8

Install instructions:

sudo dpkg -i linux-image-5.3.0-rc7_1.0-27.deb 

What’s new with this Image v18 (mainline experimental)

• 5.3.0-rc7 (minor update)
• mali gbm (GPU)
• cedrus (VPU hw decoding)
• Wifi + eth
• hdmi-sound
• DVFS
• thermal throttling
• Device Tree Overlays support

Mainline Kernel 5.3.0-rc6

This is mainline Kernel 5.3.0-rc6.

v17 mailine kernel 5.3.0-rc6 (experimental) upgrade

deb package (BROKEN - DON’T USE):

Install the new Kernel: https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v1.7

What’s new with this Image v17 (mainline experimental)

• 5.3.0-rc6 ()
• mali gbm (GPU)
• cedrus (VPU hw decoding)
• Wifi + eth
• hdmi-sound
• DVFS
• thermal throttling
• Device Tree Overlays support

• v16 mailine kernel 5.3.0-rc3 (experimental) upgrade

  deb package:

  https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v1.7

Mainline Kernel 5.3.0-rc3 (Kodi)

This is mainline Kernel 5.3.0-rc3 ready to build and run Kodi.

Bootlog: https://gist.github.com/avafinger/5a172aaac7a97d6ee186498cd74896cf

Install the new Kernel: https://github.com/avafinger/bananapi-zero-ubuntu-base-minimal/releases/tag/v16

What’s new with this Image v16 (mainline experimental)

• 5.3.0-rc3 (for building Kodi)
• mali gbm (GPU)
• cedrus (VPU hw decoding)
• Wifi + eth
• hdmi-sound
• DVFS
• thermal throttling

What’s new with this Image v14 (mainline experimental)

• 4.20.17 (for building Kodi)
• mali gbm (GPU)
• cedrus (VPU hw decoding)
• Wifi + eth
• hdmi-sound

What’s new with this Image v13 (mainline experimental)

• 4.20.17-m2z (minimum kernel)

What’s new with this Image v12 (mainline experimental)

• 4.20.0 (for testing)
• mali (experimental)

What’s new with this Image v11 (LTS experimental)

• 4.19.12 (for testing)
• mali (experimental)

What’s new with this Image v10 (LTS experimental)

• 4.19.6 (for testing)
• mali (experimental)

What’s new with this Image v9 (LTS experimental)

• mali fix (mali is back and working!)

What’s new with this Image v8 (experimental)

Image upgraded to Kernel 4.20-rc3

• operating-points-v2 (120 Mhz ~ 1008 MHz) - with sane CPU Temp. ( ~ 55.0 C )
• attempt to make mali work
• Bluetooth (working) - See Instructions on Bluetooth below

What’s new with this Image v7 (experimental)

Image upgraded to Kernel 4.20-rc2

• operating-points-v2 (240 Mhz ~ 1008 MHz) - testing only
• attempt to make mali work
• Bluetooth (need to load hci_uart module and install Bluez tools)

What’s new with this Image v6 (experimental)

Image upgraded to Kernel 4.19.1

• operating-points-v2 (480 Mhz ~ 1008 MHz)
• mali removed

What’s new with this Image v5 (experimental)

Image upgraded to Kernel 4.19.0

* operating-points-v2 working as it should (next series will be 4.19.y)
* new devfreq temp
* cma memory-reservation for mali (need a revision)

Issue:

* mali does not work, freezes kernel completely (don't use it)

What’s new with this Image v4

Image updated to Kernel 4.18.8 and has the following working:

* operating-points-v2 working as it should (next series will be 4.19.y)
* attempt to get bt working

Configuring ZRAM for the memory hungry stuffs

    sudo apt-get install zram-config
    sync && sudo reboot

On next reboot you will see if ZRAM is active:

    ubuntu@bpi-m2z:~$ ls /dev/zr*
    /dev/zram0  /dev/zram1  /dev/zram2  /dev/zram3

What’s new with this Image v3

Image updated to Kernel 4.18.4 and has the following working:

* framebuffer with 1920x1080
* mali (3D GPU) - fbdev only (Thanks to Maxime Ripard from bootlin)
* eth0 up
* wlan0 up
* i2c enabled ( /dev/i2c-0 and /dev/i2c-1 )
* spi enabled ( /dev/spidev0.0 )
* bare minimum image. (**30 Mbytes of RAM used**)
* new rootfs from scratch
* ssh enabled
* new operating-points-v2 instead of old one (experimental)

What’s new with this Image v2

Image updated to Kernel 4.17.17 and has the following working:

* framebuffer with 1920x1080
* mali (3D GPU) - fbdev only (Thanks to Maxime Ripard from bootlin)
* eth0 up
* wlan0 up
* i2c enabled ( /dev/i2c-0 and /dev/i2c-1 )
* spi enabled ( /dev/spidev0.0 )
* bare minimum image. (**30 Mbytes of RAM used**)
* new rootfs from scratch
* ssh enabled
* ZRAM / TUN modules enabled (but not configured)

Known issues:

* Hit ENTER twice to see the login prompt if you get a blank screen
* Boot with your monitor/display turned ON before you power the board
* HDMI driver is under development, Jernej (the dev. person behind the driver)
  has given some tips to fix this issue.
* Debian Bug report logs - #892229
  wireless-regdb: Missing support for kernel direct loading
  This seems to affect ubuntu 16.04 and 18.04.

To do before first boot:

• edit /etc/network/interfaces and add your SSID and password in order to use connect to your Wifi

Generate wpa-psk for Wifi AP, you can use wpa_passphrase from your linux box

Generate like so:

wpa_passphrase SSID 01234567890

where SSID is your Wifi SSID and 01234567890 your password

Edit and change accordingly:

iface wlan0 inet dhcp
wpa-ssid SSID
#psk="1234567890"
wpa-psk 93c8ff514dc02ae4944f89424d7b0d94f42ab3245cc413755ab655b8e344a2d9
dns-nameservers 8.8.8.8 8.8.4.4
wireless-power off

To do after first boot (Advanced users):

* build regulatory.db to your country for the wifi to get full power
* re-build wireless-regdb

Tips

• Board runs at ~60ºC when idle with HDMI, ~40ºC without HDMI enabled (without heatsink)

• issue in shell on first login: sudo apt-get update && sudo apt-get upgrade

  It is always a good idea to issue a: sudo shutdown -h now (and wait for the Red led Heartbeat to stop and only then unplug power)

• If you have trouble with Wifi, i suggest read Debian Bug report logs - #892229

  Regulatory.db needs to be generated somehow, until wireless-regdb is updated or rebuild it yourself.

Basic instructions to flash firmware to SD CARD

• You need a linux box
• You need a good SD CARD reader/writer (External SD CARD Reader are known to not be reliable)
  Read some heated up discussion on Armbian’s forum about how to write to SD CARD

• Get a trusted brand for the SD CARD

• insert your SD CARD into SDHC reader/writer:

  check which device is your SD CARD, type in shell:

    dmesg | tail

An output of USB SDHC reader/writer card

    [47484.133274]  sdc: sdc1 sdc2
    [47488.681276] EXT4-fs (sdc1): mounted filesystem with ordered data mode. Opts: (null)
    [47488.955328] EXT4-fs (sdc2): mounted filesystem without journal. Opts: (null)

An output of internal SDHC reader/writer card

    [ 2024.720656] mmc0: new SDHC card at address 59b4
    [ 2024.759743] mmcblk0: mmc0:59b4 SDU1  7.52 GiB 
    [ 2024.759889]  mmcblk0: p1 p2
    [ 2025.140282] EXT4-fs (mmcblk0p1): mounted filesystem with ordered data mode
    [ 2025.222858] EXT4-fs (mmcblk0p2): mounted filesystem without journal

Your device will be in the form of: /dev/sdX where X is your sd card letter (b,c,d…) or /dev/mmcblkY where Y is your device number (0,1,2…)

• format the sd card:

  in the example above, our sd card device is sdc (could be sdb)

    sudo ./format_sd_mainline.sh /dev/sdc

  or /dev/mmcblk0 if you have SDHC reader on your laptop for example

    sudo ./format_sd_mainline.sh /dev/mmcblk0

Image v2 (Kernel 4.17.4)

• flash Image to sd card (ssh enabled):

    cat rootfs_kernel_4.17.y.tar.gz.* > rootfs_kernel_4.17.y.tar.gz
    sudo ./flash_sdcard_m2z_v2.sh /dev/sdc

Image v1 (Kernel 4.15.y)

• flash Image to sd card:

    sudo ./flash_sdcard_m2z.sh /dev/sdc

• flash Image with ssh enabled to sd card:

    sudo ./flash_sdcard_m2z_ssh.sh

• Booting first time

Before you boot, configure your wifi

Connecting to AP via Wifi

Wifi use wpa_supplicant to connect to AP.
Before you boot the Image, please edit /etc/network/interfaces

iface wlan0 inet dhcp
wpa-ssid SSID <== change this
#psk="1234567890"
wpa-psk 93c8ff514dc02ae4944f89424d7b0d94f42ab3245cc413755ab655b8e344a2d9 <== change this
dns-nameservers 8.8.8.8 8.8.4.4
wireless-power off

• Login first time

You can login with

user: ubuntu

pasw: ubuntu

via serial debug or use ssh to connect remotely from your computer.

Conecting via ssh or putty:
ssh ubuntu@IP where IP is the IP assigned to the board.

First thing you should do on the first login (for v1 only)

• fix mv segment fault

  sudo apt-get install —reinstall coreutils

• fix missing service

  sudo apt-get install —reinstall systemd

• disable power management

  sudo iwconfig wlan0 power off

or in /etc/network/interfaces add this entry:

allow-hotplug wlan0
  iface wlan0 inet dhcp
  wpa-ssid your_ssid
  #psk="12345678901234567890"
  wpa-psk ababaf514dc02ae4944f89424d7b0d94f42ab3245cc413755ab655b8e344a2d9
  dns-nameservers 8.8.8.8 8.8.4.4
  wireless-power off <==== add this

reboot now:

sudo reboot

Mali benchmark

You can benchmark mali for fbdev, type in shell:

cd /home/ubuntu/mali/mali-fbdev/build/src
sudo ./glmark2-es2-fbdev

You can add FRONTBUFFER_LOCKING=1 to prevent tearing before running benchmark:

export FRONTBUFFER_LOCKING=1

[]

[]

[]

Installing a Full Desktop environment

After you setup a connection to internet, you can install a Desktop environment

sudo apt-get update
sudo apt-get dist-upgrade
sync
sudo apt-get install lxde

Wait until it finished and issue:

sync
sudo shutdown -h now (wait for the heartbeat to stop and cut power)

Reboot and you have LXDE Desktop

Bluetooth

The latest Kernel 4.20.0-rc3 upgrade has Bluetooth working.
To be able to use bluetooth follow this instructions (it should be automated via systemd service but for the sake of
documentation we do it manually) :

• Install packages

    sudo apt-get install rfkill bluez bluetooth-touch

• Load hci_uart kernel module

Edit the file /etc/modules and add bluetooth & hci_uart & rfcomm:

    # /etc/modules: kernel modules to load at boot time.
    #
    # This file contains the names of kernel modules that should be loaded
    # at boot time, one per line. Lines beginning with "#" are ignored.
    #xradio_wlan
    g_serial
    #xradio_wlan
    brcmfmac
    bluetooth
    hci_uart
    rfcomm

• Boot with the new /etc/modules

• in shell type:

    sudo su (to become root)
    brcm_patchram_plus -d --patchram /lib/firmware/ap6212/bcm43438a1.hcd --enable_hci --bd_addr 11:22:33:44:55:66 --no2bytes --tosleep 5000 /dev/ttyS1

wait untill it finish with “Done setting line discpline” (CTRL+C to end) and then:

    hciattach /dev/ttyS1 any

We should have now our Bluetooth ready, you can check:

    hcitool devi
    Devices:
        hci0    11:22:33:44:55:66

Bluetooth - How to pair a Bluetooth Phone with command line

We are going to test our bluetooth setup conecting our board to a Phone (pair with a Phone).
In a Desktop environment we have Blueman which would do it automagically but installing it would require a lot of packages
and our goal here is to have the minimum installed otherwise you go with a complete Desktop.

For this, it is necessary to install pulseaudio or you will not be able to connect to a phone.
(i think for keyboard or mouse is ok without pulse).

In order to have pulseaudio working we need to install ALSA and make it work.

    sudo apt-get install alsa-utils alsamixer libasound2 alsa-base

Edit (or create) a file /etc/asound.conf with the content:

    pcm.!default {
        type hw
        card 0
        device 0
    }
    ctl.!default {
        type hw
        card 0
    }

sync && reboot.

Check device:

    aplay -l
    **** List of PLAYBACK Hardware Devices ****
    card 0: Codec [H3 Audio Codec], device 0: CDC PCM Codec-0 []
      Subdevices: 1/1
      Subdevice #0: subdevice #0

We can check if ALSA is working, type in shell:

    alsamixer
    and un-mute and turn up the Line up and everything

and review:

    sudo amixer
    Simple mixer control 'Line In',0
      Capabilities: pvolume pvolume-joined pswitch cswitch
      Playback channels: Front Left - Front Right
      Capture channels: Front Left - Front Right
      Limits: Playback 0 - 7
      Front Left: Playback 5 [71%] [3.00dB] [off] Capture [off]
      Front Right: Playback 5 [71%] [3.00dB] [off] Capture [off]
    Simple mixer control 'Line Out',0
      Capabilities: pvolume pvolume-joined pswitch
      Playback channels: Front Left - Front Right
      Limits: Playback 0 - 31
      Mono:
      Front Left: Playback 25 [81%] [-9.00dB] [on]
      Front Right: Playback 25 [81%] [-9.00dB] [on]
    Simple mixer control 'Line Out Source',0
      Capabilities: penum
      Items: 'Stereo' 'Mono Differential'
      Item0: 'Stereo'
      Item1: 'Stereo'
    Simple mixer control 'Mic1',0
      Capabilities: pvolume pvolume-joined pswitch cswitch
      Playback channels: Front Left - Front Right
      Capture channels: Front Left - Front Right
      Limits: Playback 0 - 7
      Front Left: Playback 3 [43%] [0.00dB] [off] Capture [off]
      Front Right: Playback 3 [43%] [0.00dB] [off] Capture [off]
    Simple mixer control 'Mic1 Boost',0
      Capabilities: volume volume-joined
      Playback channels: Mono
      Capture channels: Mono
      Limits: 0 - 7
      Mono: 4 [57%] [33.00dB]
    Simple mixer control 'Mic2',0
      Capabilities: pvolume pvolume-joined pswitch cswitch
      Playback channels: Front Left - Front Right
      Capture channels: Front Left - Front Right
      Limits: Playback 0 - 7
      Front Left: Playback 3 [43%] [0.00dB] [off] Capture [off]
      Front Right: Playback 3 [43%] [0.00dB] [off] Capture [off]
    Simple mixer control 'Mic2 Boost',0
      Capabilities: volume volume-joined
      Playback channels: Mono
      Capture channels: Mono
      Limits: 0 - 7
      Mono: 4 [57%] [33.00dB]
    Simple mixer control 'Mixer',0
      Capabilities: cswitch
      Capture channels: Front Left - Front Right
      Front Left: Capture [off]
      Front Right: Capture [off]
    Simple mixer control 'Mixer Reversed',0
      Capabilities: cswitch
      Capture channels: Front Left - Front Right
      Front Left: Capture [off]
      Front Right: Capture [off]
    Simple mixer control 'ADC Gain',0
      Capabilities: cvolume cvolume-joined
      Capture channels: Mono
      Limits: Capture 0 - 7
      Mono: Capture 3 [43%] [0.00dB]
    Simple mixer control 'DAC',0
      Capabilities: pvolume pvolume-joined pswitch
      Playback channels: Front Left - Front Right
      Limits: Playback 0 - 63
      Mono:
      Front Left: Playback 45 [71%] [-20.88dB] [on]
      Front Right: Playback 45 [71%] [-20.88dB] [on]
    Simple mixer control 'DAC Reversed',0
      Capabilities: pswitch
      Playback channels: Front Left - Front Right
      Mono:
      Front Left: Playback [off]
      Front Right: Playback [off]

Testing ALSA:

    aplay /usr/share/sounds/alsa/Front_Center.wav             
    Playing WAVE '/usr/share/sounds/alsa/Front_Center.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Mono

Now install pulse:

    sudo apt-get install pulseaudio pulseaudio-module-bluetooth

sync && reboot.

Now check if pulse is running:

    ps -e|grep pulse
    1187 ?        00:00:00 pulseaudio

If everything is OK (if not, you should go back and figure out what went wrong) we can now pair with a phone using bluetooth.
Type in shell (if you have not done this yet):

    sudo su (become root)
    brcm_patchram_plus -d --patchram /lib/firmware/ap6212/bcm43438a1.hcd --enable_hci --bd_addr 11:22:33:44:55:66 --no2bytes --tosleep 5000 /dev/ttyS1
    Done setting line discpline (^C)
    hciattach /dev/ttyS1 any
    hciconfig list
    hci0:    Type: BR/EDR  Bus: UART
        BD Address: 11:22:33:44:55:66  ACL MTU: 1021:8  SCO MTU: 64:1
        UP RUNNING 
        RX bytes:1214 acl:0 sco:0 events:42 errors:0
        TX bytes:756 acl:0 sco:0 commands:42 errors:0
    hciconfig -a
    hci0:    Type: BR/EDR  Bus: UART
        BD Address: 11:22:33:44:55:66  ACL MTU: 1021:8  SCO MTU: 64:1
        UP RUNNING 
        RX bytes:934 acl:0 sco:0 events:39 errors:0
        TX bytes:744 acl:0 sco:0 commands:39 errors:0
        Features: 0xbf 0xfe 0xcf 0xfe 0xdb 0xff 0x7b 0x87
        Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3 
        Link policy: RSWITCH SNIFF 
        Link mode: SLAVE ACCEPT 
        Name: 'bpi-m2z'
        Class: 0x000000
        Service Classes: Unspecified
        Device Class: Miscellaneous, 
        HCI Version: 4.0 (0x6)  Revision: 0x6a
        LMP Version: 4.0 (0x6)  Subversion: 0x2209
        Manufacturer: Broadcom Corporation (15)

We are ready to pair. Type in shell (with your phone with bluetooth on):

    bluetoothctl -a
    [NEW] Controller 22:22:33:44:55:66 bpi-m2z [default]
    Agent registered
    [bluetooth]# devices
    [bluetooth]# list
    Controller 22:22:33:44:55:66 bpi-m2z [default]
    [bluetooth]# power on
    Changing power on succeeded
    [bluetooth]# agent on
    Agent is already registered
    [bluetooth]# default-agent
    Default agent request successful
    [bluetooth]# scan on
    Discovery started
    [CHG] Controller 22:22:33:44:55:66 Discovering: yes
    [NEW] Device 00:17:CA:F7:38:18 Haier HW-W910
    [bluetooth]# pair 00:17:CA:F7:38:18
    Attempting to pair with 00:17:CA:F7:38:18
    [CHG] Device 00:17:CA:F7:38:18 Connected: yes
    Request confirmation
    [agent] Confirm passkey 736813 (yes/no): yes
    [CHG] Device 00:17:CA:F7:38:18 Modalias: usb:v000Ap0000d0000
    [CHG] Device 00:17:CA:F7:38:18 UUIDs: 00001105-0000-1000-8000-00805f9b34fb
    [CHG] Device 00:17:CA:F7:38:18 UUIDs: 0000110a-0000-1000-8000-00805f9b34fb
    [CHG] Device 00:17:CA:F7:38:18 UUIDs: 0000110c-0000-1000-8000-00805f9b34fb
    [CHG] Device 00:17:CA:F7:38:18 UUIDs: 00001112-0000-1000-8000-00805f9b34fb
    [CHG] Device 00:17:CA:F7:38:18 UUIDs: 00001116-0000-1000-8000-00805f9b34fb
    [CHG] Device 00:17:CA:F7:38:18 UUIDs: 0000111f-0000-1000-8000-00805f9b34fb
    [CHG] Device 00:17:CA:F7:38:18 UUIDs: 0000112f-0000-1000-8000-00805f9b34fb
    [CHG] Device 00:17:CA:F7:38:18 UUIDs: 00001132-0000-1000-8000-00805f9b34fb
    [CHG] Device 00:17:CA:F7:38:18 UUIDs: 00001200-0000-1000-8000-00805f9b34fb
    [CHG] Device 00:17:CA:F7:38:18 UUIDs: 00001800-0000-1000-8000-00805f9b34fb
    [CHG] Device 00:17:CA:F7:38:18 UUIDs: 00001801-0000-1000-8000-00805f9b34fb
    [CHG] Device 00:17:CA:F7:38:18 Paired: yes
    Pairing successful
    [CHG] Device 00:17:CA:F7:38:18 Connected: no
    [bluetooth]# devices
    Device 00:17:CA:F7:38:18 Haier HW-W910
    [bluetooth]# list
    Controller 22:22:33:44:55:66 bpi-m2z [default]
    [bluetooth]# info 00:17:CA:F7:38:18
    Device 00:17:CA:F7:38:18
        Name: Haier HW-W910
        Alias: Haier HW-W910
        Class: 0x5a020c
        Icon: phone
        Paired: yes
        Trusted: no
        Blocked: no
        Connected: no
        LegacyPairing: no
        UUID: OBEX Object Push          (00001105-0000-1000-8000-00805f9b34fb)
        UUID: Audio Source              (0000110a-0000-1000-8000-00805f9b34fb)
        UUID: A/V Remote Control Target (0000110c-0000-1000-8000-00805f9b34fb)
        UUID: Headset AG                (00001112-0000-1000-8000-00805f9b34fb)
        UUID: NAP                       (00001116-0000-1000-8000-00805f9b34fb)
        UUID: Handsfree Audio Gateway   (0000111f-0000-1000-8000-00805f9b34fb)
        UUID: Phonebook Access Server   (0000112f-0000-1000-8000-00805f9b34fb)
        UUID: Message Access Server     (00001132-0000-1000-8000-00805f9b34fb)
        UUID: PnP Information           (00001200-0000-1000-8000-00805f9b34fb)
        UUID: Generic Access Profile    (00001800-0000-1000-8000-00805f9b34fb)
        UUID: Generic Attribute Profile (00001801-0000-1000-8000-00805f9b34fb)
        Modalias: usb:v000Ap0000d0000
        RSSI: -42
    [bluetooth]# list-attributes 00:17:CA:F7:38:18
    [bluetooth]# connect 00:17:CA:F7:38:18
    Attempting to connect to 00:17:CA:F7:38:18
    [CHG] Device 00:17:CA:F7:38:18 Connected: yes
    Connection successful
    [Haier HW-W910]# list-attributes 00:17:CA:F7:38:18
    [Haier HW-W910]# disconnect 00:17:CA:F7:38:18
    Attempting to disconnect from 00:17:CA:F7:38:18
    Successful disconnected
    [CHG] Device 00:17:CA:F7:38:18 Connected: no
    [bluetooth]# list-attributes 00:17:CA:F7:38:18
    [bluetooth]# info 00:17:CA:F7:38:18
    Device 00:17:CA:F7:38:18
        Name: Haier HW-W910
        Alias: Haier HW-W910
        Class: 0x5a020c
        Icon: phone
        Paired: yes
        Trusted: no
        Blocked: no
        Connected: no
        LegacyPairing: no
        UUID: OBEX Object Push          (00001105-0000-1000-8000-00805f9b34fb)
        UUID: Audio Source              (0000110a-0000-1000-8000-00805f9b34fb)
        UUID: A/V Remote Control Target (0000110c-0000-1000-8000-00805f9b34fb)
        UUID: Headset AG                (00001112-0000-1000-8000-00805f9b34fb)
        UUID: NAP                       (00001116-0000-1000-8000-00805f9b34fb)
        UUID: Handsfree Audio Gateway   (0000111f-0000-1000-8000-00805f9b34fb)
        UUID: Phonebook Access Server   (0000112f-0000-1000-8000-00805f9b34fb)
        UUID: Message Access Server     (00001132-0000-1000-8000-00805f9b34fb)
        UUID: PnP Information           (00001200-0000-1000-8000-00805f9b34fb)
        UUID: Generic Access Profile    (00001800-0000-1000-8000-00805f9b34fb)
        UUID: Generic Attribute Profile (00001801-0000-1000-8000-00805f9b34fb)
        Modalias: usb:v000Ap0000d0000
        RSSI: -42
    [bluetooth]# connect 00:17:CA:F7:38:18
    Attempting to connect to 00:17:CA:F7:38:18
    [CHG] Device 00:17:CA:F7:38:18 Connected: yes
    Connection successful
    [Haier HW-W910]# trust 00:17:CA:F7:38:18
    [CHG] Device 00:17:CA:F7:38:18 Trusted: yes
    Changing 00:17:CA:F7:38:18 trust succeeded
    [Haier HW-W910]# info 00:17:CA:F7:38:18
    Device 00:17:CA:F7:38:18
        Name: Haier HW-W910
        Alias: Haier HW-W910
        Class: 0x5a020c
        Icon: phone
        Paired: yes
        Trusted: yes
        Blocked: no
        Connected: yes
        LegacyPairing: no
        UUID: OBEX Object Push          (00001105-0000-1000-8000-00805f9b34fb)
        UUID: Audio Source              (0000110a-0000-1000-8000-00805f9b34fb)
        UUID: A/V Remote Control Target (0000110c-0000-1000-8000-00805f9b34fb)
        UUID: Headset AG                (00001112-0000-1000-8000-00805f9b34fb)
        UUID: NAP                       (00001116-0000-1000-8000-00805f9b34fb)
        UUID: Handsfree Audio Gateway   (0000111f-0000-1000-8000-00805f9b34fb)
        UUID: Phonebook Access Server   (0000112f-0000-1000-8000-00805f9b34fb)
        UUID: Message Access Server     (00001132-0000-1000-8000-00805f9b34fb)
        UUID: PnP Information           (00001200-0000-1000-8000-00805f9b34fb)
        UUID: Generic Access Profile    (00001800-0000-1000-8000-00805f9b34fb)
        UUID: Generic Attribute Profile (00001801-0000-1000-8000-00805f9b34fb)
        Modalias: usb:v000Ap0000d0000
        RSSI: -42
    [Haier HW-W910]# list-attributes 00:17:CA:F7:38:18
    [Haier HW-W910]# untrust 00:17:CA:F7:38:18
    [CHG] Device 00:17:CA:F7:38:18 Trusted: no
    Changing 00:17:CA:F7:38:18 untrust succeeded
    [Haier HW-W910]# disconnect 00:17:CA:F7:38:18
    Attempting to disconnect from 00:17:CA:F7:38:18
    Successful disconnected
    [CHG] Device 00:17:CA:F7:38:18 Connected: no
    [bluetooth]# remove 00:17:CA:F7:38:18
    [DEL] Device 00:17:CA:F7:38:18 Haier HW-W910
    Device has been removed
    [bluetooth]# list
    Controller 22:22:33:44:55:66 bpi-m2z [default]
    [NEW] Device 00:17:CA:F7:38:18 Haier HW-W910
    [bluetooth]# scan off
    [CHG] Device 00:17:CA:F7:38:18 RSSI is nil
    Discovery stopped
    [CHG] Controller 22:22:33:44:55:66 Discovering: no
    [bluetooth]# 
    [bluetooth]# quit
    Agent unregistered
    [DEL] Controller 22:22:33:44:55:66 bpi-m2z [default]

And finally you can check the Services of your Bluetooth Phone:

    dptool browse 00:17:CA:F7:38:18|grep "Service Name"
    Service Name: Generic Access Profile
    Service Name: Generic Attribute Profile
    Service Name: Audio Source
    Service Name: AVRCP TG
    Service Name: Voice Gateway
    Service Name: OBEX Object Push
    Service Name: Voice Gateway
    Service Name: OBEX Phonebook Access Server
    Service Name: Network service
    Service Name: SMS/MMS Message Access
    Service Name: Email Message Access

Bluetooth

Enbale Bluetooth on next boot (permanently)

To enable Bluetooth (BT) for every new boot, edit /etc/rc.local and add the command:

    #!/bin/sh -e
    #
    # rc.local
    #
    # This script is executed at the end of each multiuser runlevel.
    # Make sure that the script will "exit 0" on success or any other
    # value on error.
    #
    # In order to enable or disable this script just change the execution
    # bits.
    #
    # By default this script does nothing.
    # ------------------------
    # ------ enable BT -------
    # ------------------------
    # borrowed from madscientist42
    # Compute a BD_ADDR.  We're going to use pieces of the device serial number for the LAP part.
    SERIAL=`cat /proc/device-tree/serial-number | cut -c9-`
    B1=`echo $SERIAL | cut -c3-4`
    B2=`echo $SERIAL | cut -c5-6`
    B3=`echo $SERIAL | cut -c7-8`
    BDADDR=`printf b8:27:eb:%02x:%02x:%02x $((0x$B1 ^ 0xaa)) $((0x$B2 ^ 0xaa)) $((0x$B3 ^ 0xaa))`
    brcm_patchram_plus -d --patchram /lib/firmware/ap6212/bcm43438a1.hcd --enable_hci --bd_addr $BDADDR --no2bytes --tosleep 5000 /dev/ttyS1  > /tmp/bt.log 2>&1 &
    # -- BT end --------------
    exit 0
    #!/bin/bash

Make sure /etc/rc.local has run permissions:

    sudo chmod +x /etc/rc.local

Build your own Kernel

Here are the instructions for building your own kernel on board.

• Install tools

  sudo apt-get install git bison flex bc device-tree-compiler

• Get a Kernel with support for this board, for example mainline kernel 5.2.0 or your own

• Get the patch or patch set and apply to your kernel if your kernel is not complete
• Get mali support from Bootlin
• Watch linux-sunxi for the latest changes and fixes

Create directory:

mkdir -p linux
cd linux
export KVD=$PWD

Grab your kernel (here we get linus torvalds kernel 5.2 as an example):
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/refs/tags

wget https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/snapshot/linux-5.2.tar.gz
tar -xvpzf linux-5.2.tar.gz
cd linux-5.2

Build:

make sunxi_defconfig
#make  menuconfig (if you want to add or change kernel modules)
make  oldconfig
make INSTALL_MOD_PATH=output zImage 
make INSTALL_MOD_PATH=output dtbs
make INSTALL_MOD_PATH=output modules
make INSTALL_MOD_PATH=output modules_install
export KV=$(strings ./arch/arm/boot/Image |grep "Linux version"|awk '{print $3}')
make INSTALL_HDR_PATH=output/usr/src/linux-headers-${KV} headers_install

Install:

sudo cp -vfr ./output/* /
sync
sudo cp -fv ./arch/arm/boot/zImage /boot/zImage_${KV}
sync
sudo cp -fv ./arch/arm/boot/dts/sun8i-h2-plus-bananapi-m2-zero.dtb /boot/bpi-m2-zero.dtb_${KV}
sync

Make it current kernel

cd /boot
sudo ln -sf zImage_${KV} zImage
sudo ln -sf bpi-m2-zero.dtb_${KV} bpi-m2-zero.dtb
cd ${KVD}
sync

Reboot

sudo reboot

You can add or change kernel modules at any time and modify your dts to get the hw peripherals to work properly.
From now on you are at your own.

Working with Cameras

There is support for camera in mainline kernel. You can use a USB camera or the OV5640 camera (DVP).
In general, USB camera are slower than the DVP camera, you can stream video at 20 FPS with DVP camera and 10 FPS for the USB camera.
The quality of the image is highly dependent on the lens used. Using a sensor without AF is recommended if you use mainline kernel.

• USB camera
• OV5640 DVP camera

USB Camera

Once you attach the USB camera you will see the device node representing the camera, that is:

ubuntu@bpi-m2z:~$ ll /dev/video*
crw-rw---- 1 root video 81, 0 Apr 11  2019 /dev/video0
crw-rw---- 1 root video 81, 1 Apr 11  2019 /dev/video1
crw-rw---- 1 root video 81, 3 Nov  8 13:29 /dev/video2
crw-rw---- 1 root video 81, 4 Nov  8 13:29 /dev/video3

and media information in:

ubuntu@bpi-m2z:~$ ll /dev/media*
crw-rw-rw- 1 root video 243, 0 Apr 11  2019 /dev/media0
crw-rw-rw- 1 root video 243, 1 Apr 11  2019 /dev/media1
crw-rw-rw- 1 root video 243, 2 Nov  8 13:29 /dev/media2

To find about the topology of the camera you would do:

ubuntu@bpi-m2z:~$ media-ctl --device /dev/media2 --print-topology
Media controller API version 5.7.10
Media device information
------------------------
driver          uvcvideo
model           USB 2.0 Camera: HD 720P Webcam
serial          
bus info        usb-1c1a000.usb-1.2
hw revision     0x0
driver version  5.7.10
Device topology
- entity 1: USB 2.0 Camera: HD 720P Webcam (1 pad, 1 link)
        type Node subtype V4L flags 1
        device node name /dev/video2
    pad0: Sink
        <- "Extension 4":1 [ENABLED,IMMUTABLE]
- entity 4: USB 2.0 Camera: HD 720P Webcam (0 pad, 0 link)
        type Node subtype V4L flags 0
        device node name /dev/video3
- entity 8: Extension 4 (2 pads, 2 links)
        type V4L2 subdev subtype Unknown flags 0
    pad0: Sink
        <- "Processing 3":1 [ENABLED,IMMUTABLE]
    pad1: Source
        -> "USB 2.0 Camera: HD 720P Webcam":0 [ENABLED,IMMUTABLE]
- entity 11: Processing 3 (2 pads, 2 links)
         type V4L2 subdev subtype Unknown flags 0
    pad0: Sink
        <- "Camera 1":0 [ENABLED,IMMUTABLE]
    pad1: Source
        -> "Extension 4":0 [ENABLED,IMMUTABLE]
- entity 14: Camera 1 (1 pad, 1 link)
         type V4L2 subdev subtype Unknown flags 0
    pad0: Source
        -> "Processing 3":0 [ENABLED,IMMUTABLE]