Display the HDMI and LCD output simultaneously

We want to display the HDMI and LCD output simultaneously with different monitors. we have done with the following commands at runtime in U Boot console and Bootloader Env variables in uEnv.txt

setenv vidargs video=mxcfb1:video=dev=hdmi,800x480M@60,if=RGB24 video=mxcfb0:dev=lcd,800x480@60,if=RGB666 fbmem=32M

vidargs'mxc_hdmi.only_cea=1 video=mxcfb1:dev=hdmi,800x480M@60,if=RGB24 video=mxcfb0:dev=lcd,800x480@60,if=RGB666 fbmem=32M'

After Executing the above commands we are able to get only one display at a time for another one only signal.

Note:only mxcfb0(framebuffer) output will display either HDMI or LCD

We also tried updating kernel using overlay modules “colibri-imx6_lcd-lt161010_overlay.dtbo” and "colibri-imx6_hdmi_overlay.dtbo " in /boot but here also we can select one at a time.

Kindly correct me if i have misconfigured above data.

Is there a way to display HDMI and LCD outputs simultaneously ?

Image : Colibri-iMX6_Reference-Minimal-Image-Tezi_5.4.0
Linux Kernel : 5.4.91-5.2.0-devel+git.c59b3c2da1e9

Hi @Gowthami ,

Can you please share your overlay.txt content and output of ls /sys/class/drm command.
Also please use Reference multimedia image for testing. You may need to modify weston to enable second display as per resolution and type of display.

Best Regards
Ritesh Kumar

Hello @ritesh.tx ,

1.We can use Reference multimedia image but the image is too heavy and it has lot of QT stuffs which we are not using.

2.Output of ls /sys/class/drm card0 renderD128 version

3.Yes we have modified the /etc/xdg/weston /vi weston.ini to enable the second display as mentioned below.



  1. Overlays.txt content fdt_overlays=colibri-imx6_lcd-vga_overlay.dtbo colibri-imx6_hdmi_overlay.dtbo
    overlays.txt (78 Bytes)

Note:We’re moving on to the carrier board development phase and a quick support will be highly appreciated.

Hi @Gowthami,
Quickly checking, I can see multiple framebuffer

root@colibri-imx6:~# cat /etc/issue
TDX Wayland with XWayland 5.3.0+build.10 (dunfell) \n \l
root@colibri-imx6:~# fw_printenv vidargs
vidargs=video=mxcfb1:video=dev=hdmi,1024x600@60,if=RGB24 video=mxcfb0:dev=lcd,800x480@60,if=RGB666 fbmem=32M
root@colibri-imx6:~# ls /dev/fb*
/dev/fb  /dev/fb0  /dev/fb1  /dev/fb2

iMX6 do not support such configuration. Perhaps you can try from application itself, don’t know what performance to expect. One way is to use gstreamer pipeline e.g

gst-launch-1.0 -v multifilesrc location=/dev/fb0 ! videoparse format=29 width=800 height=480 framerate=30/1 ! decodebin ! videoscale ! video/x-raw,width=1024,height=600 !  videoconvert ! fbdevsink device=/dev/fb2 sync=false

Another method would be to start two application using individual framebuffer.

Best Regards
Ritesh Kumar

Hello @ritesh.tx

Requirement is to enable the different peripherals (LCD and HDMI) simultaneously through SOM itself.

Enabling from Application is not recommended.

Thank you for concluding the issue quickly.