Running Xorg on Raspberry Pi through Docker

**escalade** · May 1, 2016 at 1:41 PM

Thanks to Irusak's awesome Docker addon we are now closer to running web browsers and other X11 apps on the Raspberry Pi. However, I'm having problems getting Xorg to work inside a container. Specifically, there is no output. I can launch Xorg just fine and it correctly chooses the framebuffer driver.

Here's how I start my container:

Code

# docker run -it --privileged --name ubuntu -v /var/media:
/media -v /var/run/dbus:/run/dbus armhf/ubuntu

Here's the relevant Xorg log:

Code

(II) Loading sub module "fbdevhw"
(II) LoadModule: "fbdevhw"
(II) Loading /usr/lib/xorg/modules/libfbdevhw.so
(II) Module fbdevhw: vendor="X.Org Foundation"
    compiled for 1.18.3, module version = 0.0.2
    ABI class: X.Org Video Driver, version 20.0
(II) FBDEV(0): using default device
(WW) VGA arbiter: cannot open kernel arbiter, no multi-card support
(II) FBDEV(0): Creating default Display subsection in Screen section
    "Default Screen Section" for depth/fbbpp 24/32
(==) FBDEV(0): Depth 24, (==) framebuffer bpp 32
(==) FBDEV(0): RGB weight 888
(==) FBDEV(0): Default visual is TrueColor
(==) FBDEV(0): Using gamma correction (1.0, 1.0, 1.0)
(II) FBDEV(0): hardware: BCM2708 FB (video memory: 0kB)
(II) FBDEV(0): checking modes against framebuffer device...
(II) FBDEV(0): checking modes against monitor...
(--) FBDEV(0): Virtual size is 1x1 (pitch 1)
(**) FBDEV(0):  Built-in mode "current"
(==) FBDEV(0): DPI set to (96, 96)
(II) Loading sub module "fb"
(II) LoadModule: "fb"
(II) Loading /usr/lib/xorg/modules/libfb.so
(II) Module fb: vendor="X.Org Foundation"
    compiled for 1.18.3, module version = 1.0.0
    ABI class: X.Org ANSI C Emulation, version 0.4
(**) FBDEV(0): using shadow framebuffer
(II) Loading sub module "shadow"
(II) LoadModule: "shadow"
(II) Loading /usr/lib/xorg/modules/libshadow.so
(II) Module shadow: vendor="X.Org Foundation"
    compiled for 1.18.3, module version = 1.1.0
    ABI class: X.Org ANSI C Emulation, version 0.4
(II) UnloadModule: "modesetting"
(II) Unloading modesetting
(==) Depth 24 pixmap format is 32 bpp
(==) FBDEV(0): Backing store enabled
(==) FBDEV(0): DPMS enabled
(==) RandR enabled
(II) SELinux: Disabled on system
(II) AIGLX: Screen 0 is not DRI2 capable
(EE) AIGLX: reverting to software rendering
(II) AIGLX: enabled GLX_MESA_copy_sub_buffer
(II) AIGLX: Loaded and initialized swrast
(II) GLX: Initialized DRISWRAST GL provider for screen 0

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It runs fine and I can launch Xorg apps, but the screen remains blank. This leads me to believe it's related to the fact that the Raspberry Pi does not have any virtual terminals enabled under LibreELEC/OpenELEC. In fact, if you boot with "tty" on the kernel command line, you can see debug-shell spawning a shell, but there is nothing displayed on the screen when doing "chvt 3".

I've tried the same on Generic, and it works great. I can spawn X11 apps and have them display on the local X server, or run an X server in the container.

Any ideas?

**lrusak** · May 1, 2016 at 6:25 PM Official Post

I don't believe it is possible because there is no xorg running that x11 can forward to.

See, Running GUI apps with Docker – Fábio Rehm

**escalade** · May 1, 2016 at 6:46 PM

Yes it's possible, I can run Xorg server fine in a container on Generic. With Docker you can do anything that you can do in other distributions as long as your kernel supports it. The problem is with the RPi, Xorg is not displaying anything on the framebuffer. Some piece of the puzzle is missing, either a kernel option or perhaps in the device tree overlay.

I'm unable to get a regular TTY displaying on the framebuffer as well under LibreELEC/OpenELEC. This is something that should definitely be possible.

Looks like the kernel is bound to the dummy console:

Code

OpenELEC:~ # cat /sys/class/vtconsole/vtcon0/name 
(S) dummy device
OpenELEC:~ # cat /sys/class/vtconsole/vtcon1/name 
(M) frame buffer device
OpenELEC:~ # cat /sys/class/vtconsole/vtcon0/bind 
1

Trying to bind the console to the framebuffer like this:

Code

OpenELEC:~ # echo 1 > /sys/class/vtconsole/vtcon1/bind

Results in a kernel crash:

Code

[  439.904849] Unable to handle kernel paging request at virtual address b138b000
[  439.904854] pgd = 9f8a4000
[  439.904864] [b138b000] *pgd=2d210811, *pte=00000000, *ppte=00000000
[  439.904872] Internal error: Oops: 807 [#1] SMP ARM
[  439.904932] Modules linked in: hci_uart btbcm bluetooth ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 xt_addrtype iptable_filter ip_tables xt_conntrack x_tables nf_nat nf_conntrack br_netfilter bridge stp llc 8021q brcmfmac brcmutil cfg80211 snd_bcm2835 snd_pcm bcm2835_gpiomem bcm2835_wdt snd_timer snd overlay
[  439.904942] CPU: 0 PID: 707 Comm: sh Not tainted 4.6.0-rc5 #1
[  439.904944] Hardware name: BCM2709
[  439.904949] task: abe5c280 ti: 9f892000 task.ti: 9f892000
[  439.904962] PC is at bitfill_aligned+0x94/0x148
[  439.904967] LR is at bitfill_aligned+0x84/0x148
[  439.904975] pc : [<8044fc34>]    lr : [<8044fc24>]    psr: 200d0013
[  439.904975] sp : 9f893c58  ip : 9f893c80  fp : 9f893c7c
[  439.904979] r10: 00000000  r9 : 00000000  r8 : ffffb020
[  439.904983] r7 : ffffb020  r6 : 00000000  r5 : b138aa00  r4 : 00000000
[  439.904988] r3 : b138affc  r2 : b138b000  r1 : 07fffc01  r0 : 07fffd81
[  439.904994] Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[  439.904999] Control: 10c5383d  Table: 1f8a406a  DAC: 00000055
[  439.905004] Process sh (pid: 707, stack limit = 0x9f892210)
[  439.905008] Stack: (0x9f893c58 to 0x9f894000)

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What I don't get is that during boot the Raspberry Pi framebuffer seems to work fine, as the boot logo is showing. During an update text is displayed on the console as well. If I boot with "debugging break=mount_storage" I get a debugging shell displayed on the framebuffer, and when I run fbset there it says the mode is "1824x984-0", but after a regular boot to Kodi and stopping Kodi, it says 1x1.

It seems like when the Kodi target is reached, the console framebuffer is disabled somehow, and I believe this to be the reason. Hoping that someone has some insight on this.
[hr]

EDIT:

I'm happy to report success, the problem was because of the fbset.service:

Code

[Unit]
Description=Framebuffer setup
After=multi-user.target


[Service]
Type=oneshot
ExecStart=/sbin/fbset -g 1 1 1 1 32


[Install]
WantedBy=graphical.target

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Which reduces the size to 1x1 pixels. After a "fbset -g 1920 1080 1920 1080 32" I can start an X server and start Chromium. There is one remaining issue, I can't seem to use mouse/keyboard inside X. Will investigate further

**escalade** · May 1, 2016 at 9:26 PM

More success! Xorg doesn't detect input devices because udev isn't working inside Docker. Solved by adding manual configuration in /etc/X11/xorg.conf.d/10-inputs.conf:

Code

Section "ServerFlags"
    Option "AutoAddDevices" "false"
EndSection


Section "InputDevice"
    Identifier "Keyboard0"
    Option "CoreKeyboard"
    Option "Device" "/dev/input/event0"
    Driver "evdev"
EndSection


Section "InputDevice"
    Identifier "Mouse0"
    Option "CorePointer"
    Driver "evdev"
    Option "Device" "/dev/input/event1"
EndSection

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Chromium segfaults for me both in Debian and in Arch, not sure what's up with that, but I got Firefox up and running so I'm happy

**lrusak** · May 1, 2016 at 10:32 PM Official Post

Quote from escalade
More success! Xorg doesn't detect input devices because udev isn't working inside Docker. Solved by adding manual configuration in /etc/X11/xorg.conf.d/10-inputs.conf:
Code
Section "ServerFlags"
    Option "AutoAddDevices" "false"
EndSection


Section "InputDevice"
    Identifier "Keyboard0"
    Option "CoreKeyboard"
    Option "Device" "/dev/input/event0"
    Driver "evdev"
EndSection


Section "InputDevice"
    Identifier "Mouse0"
    Option "CorePointer"
    Driver "evdev"
    Option "Device" "/dev/input/event1"
EndSection
Display More
Chromium segfaults for me both in Debian and in Arch, not sure what's up with that, but I got Firefox up and running so I'm happy

pretty cool. I'll setup a repo soon for dockerfiles related to LibreELEC. Then we can create one specifically for chromium or firefox.

hollol · August 10, 2016 at 7:58 AM

Hello escalade, I am very interested in your Firefox-Docker approach. Could you please share your Dockerfile?

Best, Lars

**escalade** · August 10, 2016 at 9:32 AM

As you can see above, no Dockerfile was used. I simply pulled the armhf/ubuntu image and launched Firefox on that.

**awiouy** · September 11, 2016 at 11:54 PM Official Post

Hey escalade!

I am trying to run Firefox on my Pi with the information you provide.
I am however new to Docker, and I have a hard time filling the gaps, eg:
- the ubuntu/armhf image does not ship xorg and firefox, you have to install them
- how should xorg and firefox be started
- fbset.service is absent from LibreELEC and Ubuntu
- etc

Thank you in advance for any help

**escalade** · September 12, 2016 at 11:06 AM

Yes, you need to install them. Start them as you would any binary, keep in mind that X applications need the DISPLAY variable set. The call to fbset was moved into a Kodi patch.

**awiouy** · September 13, 2016 at 1:27 AM Official Post

Hello escalade,

I progressed a little:
- in LE:
- fbset -g 1920 1080 1920 1080 32 (to enable the frame buffer device)
- systemctl stop kodi (to stop Kodi)
- in the Docker container
- apt install firefox xorg -y (to install Firefox and X.org)
- startx -- :0 & (to start X.org)
- DISPLAY=:0 firefox (to start Firefox)

Firefox displays on the screen.
I however had stop stop Kodi to display Firefox on the screen.
I had copied the /etc/X11/xorg.conf.d/10-inputs.conf you provide, but the keyboard remained unresponsive.

Had you managed to display Firefox on top of Kodi? Do you remember how?
As for the keyboard, I have a feeling that a link is missing between LE and the container. What do you think.

Thank you for any help further.

**escalade** · September 13, 2016 at 1:38 PM

I stopped Kodi as well I think. Why would you want to run both? It's not like the Pi is powerful enough to play a video and browse at the same time. You'd need to release the audio device in any case, then Kodi is useless. Unless perhaps you installed Pulse, but again CPU power comes into play.

As for the keyboard, I can't recall doing anything special to get it working. It definitely worked though. Are you sure that your 10-inputs.conf was read? I believe I used Arch, check that the path is the same for Ubuntu.

sukanime · September 24, 2016 at 3:40 PM

i'am sory, i'am newbie to LibreELEC and Docker.
i just want to run Firefox in LibreELEC, then Google it, then i go to this thread.

i have LibreELEC 7.0.2.007 running, the i go to add on , browse Kodi Addons, but i cannot find Docker add on in there....
so how to install the add on?

is there how to for newbie like me?

Thanks...

**dead** · October 1, 2016 at 5:05 AM

Hey guys... I think I was able to run the official chromium browser from raapbian in dockers.
I'm not really sure if it's decoding the video via hardware or not. But I think it is possible.

I intend to write an addon to this but I'must kinda busy right now.

**dead** · October 5, 2016 at 6:53 PM

Uploading a new version of the "chromium-elec". Pretty sure now it is working.
It even has an cec input, but it is slow.

Build the Dockerfile in the docker folder using:

Code

docker build -t chrome .

Config.txt

Code

dtparam=audio=on
disable_overscan=1

Then just execute the run.sh

It is using the mmal to accelerate the h264 decoding but unfortunately it doesn't work really well. (tested in a raspberry pi 2).

**awiouy** · October 8, 2016 at 1:04 PM Official Post

Quote from dead
Uploading a new version of the "chromium-elec". Pretty sure now it is working.
It even has an cec input, but it is slow.

Build the Dockerfile in the docker folder using:
Code
docker build -t chrome .
Config.txt
Code
dtparam=audio=on
disable_overscan=1
Then just execute the run.sh

It is using the mmal to accelerate the h264 decoding but unfortunately it doesn't work really well. (tested in a raspberry pi 2).

Hello dead!

First, thank you for your efforts, they look promising.

Then, I tried to follow your instructions, but run.sh fails with
/bin/sh: 1: /tmp/run.sh: Permission denied
I am running LE 7.90.006 for RPi2 on a RPi3.

Finally, if I can make it work, I would like to wrap it in a addon.
Do you intend to host the image on Docker Hub?

Thank you for your help

**dead** · October 8, 2016 at 2:47 PM

Quote from awiouy

Hello dead!

First, thank you for your efforts, they look promising.

Then, I tried to follow your instructions, but run.sh fails with
/bin/sh: 1: /tmp/run.sh: Permission denied
I am running LE 7.90.006 for RPi2 on a RPi3.

Finally, if I can make it work, I would like to wrap it in a addon.
Do you intend to host the image on Docker Hub?

Thank you for your help

Thanks!
Feel free to write the addon, and yes, I intend to host the image on Docker Hub.
I'm trying to improve the cec input right now.

**awiouy** · October 8, 2016 at 2:50 PM Official Post

Quote from dead

Thanks!
Feel free to write the addon, and yes, I intend to host the image on Docker Hub.
I'm trying to improve the cec input right now.

What about run.sh failing?

**dead** · October 8, 2016 at 2:57 PM

Quote from awiouy

What about run.sh failing?

Missing chmod in Dockerfile.
Try running "chmod +x input.sh run.sh" before building the docker image.