RealVNC / x11vnc / TigerVNC — impossible to screen-mirror on uConsole CM5 (Debian Trixie, Panfrost) — “Cannot currently show the desktop”

uConsole
1

Hi everyone,

I’m running a fresh install of Debian Trixie ARM64 for uConsole CM5 (the build from Rex, with the Control Centre).
I’m trying to enable VNC screen mirroring of the actual display (:0) — not a virtual desktop.

However, after extensive testing, it seems that no VNC server is able to mirror the physical screen on this setup.
Here are the details.

What I tried

1. x11vnc

Installed and launched with:

x11vnc -display :0 -rfbauth ~/.vnc/passwd -forever -shared

Result:

X Error: BadMatch (X_GetImage)

= x11vnc cannot capture the framebuffer at all.

This is consistent on Mali/Panfrost with DRM/KMS.

2. TigerVNC

The Debian ARM64 packages do not include x0vncserver, so screen mirroring is impossible.
Only virtual desktops are supported:

  • Xtigervnc

  • tigervncserver
    No x0vncserver.

So TigerVNC works only for virtual sessions, not the real display.

3. RealVNC Server (official ARM64 build)

I installed RealVNC from the Raspberry Pi repository (v7.13.1).
Authentication works perfectly, but screen capture fails.

The RealVNC client connects but shows this error:

"Cannot currently show the desktop"

In the server logs:

Connections: disconnected ([ConnFailed] No configured security type is supported...)
Connections: disconnected ([AuthFailure] ...)
Cannot currently show the desktop

I tested:

  • Service Mode (vncserver-x11-serviced)

  • User Mode (vncserver-x11 -newinstance)

  • Forcing DISPLAY=:0

  • SystemAuth and VncAuth

  • PAM changes

  • LXQt / Openbox

Always ends with the same result: RealVNC cannot capture the screen.

My conclusion so far

On uConsole CM5 + Debian Trixie + Panfrost, there is currently:

  • No working screen mirroring solution (x11vnc fails, RealVNC fails, TigerVNC lacks x0vncserver).

  • Only virtual VNC desktops appear to work reliably.

My questions

  1. Is screen mirroring expected to work on uConsole CM5 with Panfrost?
    If yes, which display stack is required?

  2. Is there any known workaround to allow framebuffer capture (X11 or DRM) on this device?

  3. Would switching to GNOME (Wayland + gnome-remote-desktop) help?
    Has anyone tested this on the CM5?

  4. Is there a recommended distribution or configuration where RealVNC or x11vnc does work with the CM5 GPU drivers?

I’m happy to test patches, alternate Xorg configs, or different window managers if needed.

Thanks for any guidance — I know this is a complex configuration, and any insight from the community would be extremely helpful.

— Pierre

1 Like
2

Try this

Terminal-

sudo raspi-config

6 Advanced Options

A7 Wayland

w2 Labwc window manager with wayland

Make sure the wayland option is active.

reboot and give it a go.

1 Like
3

thanks, it worked with wayvnc!

1 Like
4

Where did you download Rex’s Trixie from do you have the link?

5
6

Thanks Rex im downloading it now…hopefully will work. Do I need to edit the config.txt for trying it in the uconsole?

7

Nope, only if you have a DevTerm