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Videostrong KII Pro (videostrong-kii-pro)

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Videostrong KII Pro
Videostrong KII Pro
Videostrong KII Pro
Manufacturer Videostrong
Name KII Pro
Codename videostrong-kii-pro
Released 2016
Hardware
Chipset Amlogic S905
CPU 2.0 GHz Quad core
GPU Mali 450
Storage 16 GB eMMC
Memory 2 GB
Architecture aarch64
Software
Original software Android
Original version 5.1.1 (+ preinstalled KII Pro software and a different launcher)
FOSS bootloader yes
postmarketOS
Category testing
Pre-built images no
Mainline yes
postmarketOS kernel 6.2.9
Features
Flashing
Broken
Internal storage
No data
SD card
No data
Multimedia
3D Acceleration
Works
Built-in DVB
Broken
Audio
Works
IR RX
Works
Connectivity
WiFi
Works
Bluetooth
Works
Ethernet
Works
Miscellaneous
FDE
No data
USB-A
Works
HDMI/DP
Works
U-Boot
Primary Bootloader
Works
Secondary Bootloader
Works
Mainline
Partial
Internal Storage
No data
SD card
Works
USB Host
No data
Display
Works
Keyboard
Broken

The KII Pro is a set-top box made by Videostrong, using an Amlogic S905 SoC, and running a custom (proprietary) fork of AOSP. It also comes with DVB inputs and an infrared TV remote.

Beaware of different versions

There were different versions of this TV box, all made by the same manufacturer.

Videostrong just happens to (re)sell some of their products under the Mecool brand, with different hardware.

The 2 known versions of the KII Pro are the "original" KII Pro (the version this port is made for), which uses the Amlogic S905 SoC, and the newer Mecool KII Pro, which uses the Amlogic S905D SoC instead. They both look the same except the newer one most likely has a Mecool logo on the front, and the Mecool KII Pro seems to use Android 7.1.1 instead of Android 5.1.1. If you own the Mecool KII Pro then this port won't work there without some changes. It may work by using the right DTB file though but that's untested since F doesn't own a Mecool KII Pro.

How to enter flash mode

You need a USB Type-A to USB Type-A cable.

  • Unplug everything from your set-top box
  • Plug your USB cable to the USB port at the top left (other USB ports won't work)
     this one
_______ \/ ____________
        __   __     || \
       |__| |__|    ||  \
   __  |__| |__|    ||   \
__________________________\
  • Press and hold the reset button
 _||_||____________
|                  |
| O              O |
|   ------------   |
|   ------------. < here
|   ------------   |
|   ------------   |
| O              O |
|__________________|
  • While holding the reset button, plug the USB cable to your computer
  • After 5 seconds or so, release the reset button
  • Run lsusb, you should see something like this:
$ lsusb
[...]
Bus 003 Device 004: ID 1b8e:c003 Amlogic, Inc. 
[...]

But that's not really needed unless you bricked your set-top box (which is very unlikely as postmarketOS doesn't touch the internal eMMC yet, unless, of course, you wiped the eMMC from postmarketOS). You'd also need a computer running Microsoft Windows with the Amlogic USB Burner or Amlogic Update if you wish to use GNU+Linux. Both software are proprietary.

Note If the eMMC and SD card are not bootable, the set-top box will likely boot into the flash mode. Again, untested.

How to enter recovery mode

Also not needed. Press the reset button once while booting. You'll be booted to an Android recovery, where it may be possible to flash postmarketOS, but this is untested.

Installation

Only installing to an SD card works currently.

Use pmbootstrap to build your own image, like so:

$ pmbootstrap init
installing to an SD card. change 'mmcblkX' with the path of your SD card. 
THIS WILL ERASE ALL DATA IN YOUR SD CARD
$ pmbootstrap install --sdcard=/dev/mmcblkX

What you need to do, basically is:

  1. Select the correct release channel (this device is currently only supported by edge)
  2. Select the right manufacturer (videostrong)
  3. Select the right device codename (kii-pro)
  4. Choose if you want nonfree firmware or not (required for working Wi-Fi and bluetooth)
  5. Answer all the other questions as you wish

Then:

  1. Put the SD card you installed postmarketOS on in the SD card slot
  2. The steps below need to be done only once (unless you format the internal eMMC)
    1. Unplug the power supply
    2. Press and hold the reset button below your TV box
    3. While holding the reset button, plug in your power supply back
    4. Keep holding the reset button until your screen gets a signal

A mainline U-Boot should load, and postmarketOS should boot up.

What works

See the device status at the top (mobile) or at the right (desktop).

Click to enlarge
Click to enlarge

UART

UART works, but is disabled by default when booting postmarketOS. You can enable UART in postmarketOS by editing the extlinux/extlinux.conf file located in the boot partition.

Find this line:

  append console=null PMOS_NO_OUTPUT_REDIRECT

And change it to:

  append console=ttyAML0,115200 PMOS_NO_OUTPUT_REDIRECT

Then connect RX, TX, and Ground to your USB-to-TTL, according to the pinout shown. DO NOT CONNECT THE 3V3 PAD

Afterwards, you can now run:

# microcom -s 115200 /dev/ttyUSB0 # replace /dev/ttyUSB0 with the path of your USB-to-TTL device


LEDs

The 2 LEDs the device has are functionnal.

Use /sys/class/leds/red:status to control the LEDs, like this for example:

# echo 1 > /sys/class/leds/red:status/brightness # red: on, blue: off
# echo 0 > /sys/class/leds/red:status/brightness # red: off, blue: on

DVB hardware

See Videostrong KII Pro (videostrong-kii-pro)/DVB.

IR Receiver

Works! No setup is needed apart from using an interface that's optimized for remote controls.

Wi-Fi and Ethernet

Wi-Fi works, but requires a nonfree firmware. It also doesn't seem to work properly sometimes. This issue also happens on the Xiaomi POCO F1 (xiaomi-beryllium). Doesn't happen on LibreELEC, which doesn't use NetworkManager, so it may be a problem with NetworkManager after all.

The TV box has an 8P8C port used for connecting to the internet (so-called 'Ethernet port') which works fine on postmarketOS as long as you boot it using a mainline U-Boot chainloaded from the vendor U-Boot. This weird quirk has to do with the device tree.

Bluetooth

Bluetooth works, but requires nonfree firmware. It also requires a DTS patch which has been sent upstream.

FOSS bootloader

The KII Pro uses U-Boot as its primary bootloader. U-Boot v2020.07 (with some minor modifications) works on the TV box. Newer versions also work, although HDMI output (until postmarketOS boots) and ethernet are broken.

Audio

Works. Needs a DTS kernel patch, which has been sent upstream. There are no ALSA UCM configs, so you may need to tinker around a little bit with alsamixer for HDMI audio to work, which is fairly straightforward. And when you're done, you can save your configuration with this command:

# alsactl store
TODO TODO: ALSA UCM

Hardware acceleration

Seems to work! Weston and Plasma, as well as Plasma Bigscreen run fine on the device and the postmarketOS demos work fine too. Video encoding/decoding doesn't work however.

X11

Works fine. A custom configuration file is needed else it crashes (included).

HDMI-CEC

Sort of works. The TV detects a CEC device, but you cannot use the TV's remote to control the set-top box (at least, on Plasma Bigscreen). Seems like libcec does detect which button in the remote is pressed.

UIs

Most UIs are expected to work, although you may want to use one suited for televisions (such as Plasma Bigscreen).

(This list isn't in any particular order)

Name Display server Notes
Phosh Wayland Works.
KDE Plasma Desktop Wayland Works. A little unstable.
KDE Plasma Mobile Wayland Doesn't work. After the lockscreen it's completly unusable.
KDE Plasma Bigscreen Wayland Works.
Weston Wayland Works. The cursor disappears sometimes when using an XWayland app. A little unstable (less than Plasma Desktop)
LXQt X11 Works.
Kodi on framebuffer - Works.
GNOME and GNOME Classic Wayland Works. A little laggy.
SXMO X11 Works.
SXMO Wayland Works.
MATE X11 Works.
XFCE4 X11 Works.

Disassembly guide

TODO TODO: Good disassembly guide.
  • Flip your set-top box and unscrew the following screws:
         | | | |
       __| |_| |_______________________________
      |                                        |
      |   ( )                           ( )    |
      |                                        |
      |                                        |
      |                                        |
      |                                        |
      |                                        |
      |                                        |
      |                                        |
 this >   (o)                        o  ( )    |
      |                             /\         |
      |_________________________ and this  ____|
  • Unscrew the nut in the DVB-S2 port
  • Pry the top casing

Pictures

Boot process (very simplified)

(Useful for porting other OSes to it)

                    if emmc   +------+
                  +---------->| emmc |---------------+
                  |           +------+               |
 +---------+      | else if sd card   +---------+    |
 | bootrom |------+------------------>| sd card |    |
 +---------+      |                   +---------+    |
                  +-----[...]                        | 
                                                     |
        +------------------[...]---------------------+
        |      
        |                                          +---------+     +-------------------+     +-----------------+
        v                                    +---->| sd card |---->| 's905_autoscript' |---->| v2020.07 u-boot |
 +---------------+  if sd and multiboot mode |     +---------+     +-------------------+     +-----------------+
 | vendor u-boot |---------------------------+                                                        |
 +---------------+              else if emmc |     +------+     +-----------------------------+       v 
                                             +---->| emmc |---->| vendor's android 5.1.1 fork |   +----------+
                                                   +------+     +-----------------------------+   | extlinux |
                                                                                                  +----------+
                                                                                                       |
                                                                                                       v
                                                                                                +--------------+
                                                                                                | postmarketOS |
                                                                                                +--------------+

Replace the vendor U-Boot

See Running mainline U-Boot as the primary bootloader

Community info

Maintainers

  • F (f_ on OFTC and Libera, @notrealvitali64:matrix.org on Matrix (NOT USED. PLEASE USE IRC))

Contributors

  • exkc ( @root:exkc.moe/@exxxxkc:yatrix.org/@exxxxkc:matrix.org/@af2e02839bcfb0aae789a9ea66f63afff6bc14a5c1685be36c6db57fcf2cdc6f78176afe0ffab58e82d82df2457744c693593ebc9ac063e65a1e6260503ef373:the-apothecary.club/@exxxxkc:cuteworld.space on Matrix)

Users owning this device

  • FerassElHafidi (Notes: Wiped eMMC. Amlogic secureboot not enabled. Now only boots Amlogic firmware from an SD card. pmOS installed on SD.)


See also