Force HDMI OUTPUT

  • Hi People,

    OS: Libreelec 18.9 (9.2.6)

    Hardware: Old Laptop AMD -E-450 with Radeon HD Graphics

    how to force boot from hdmi ?

    NOTE:

    If it turns on with the TV turned off, it stops recognizing the HDMI. Need a new BOOT with the TV on. Tried to reconnect the HDMI cable more than once. He doesn't recognize it.

    config.txt does not exist

    Some solutions for raspberry pi did not work on laptop

  • A few observations:

    - VERY old laptop, AMD E450

    - Booting with HDMI, not from HDMI

    - Every laptop has a key combination to enable an external monitor. Is that getting in the way?

    - If the TV is off, there can obviously be no HDMI-handshake (deciding on with resolution and framerate for example)

    - If a config.txt file does not exist, then simply create one using the "nano" editor.

  • 1) You have to use Cusom EDID.

    2) You may have to disable the display and to force HDMI output via kernel parameters. Use

    Code
    head /sys/class/drm/*/status

    to identify the device names.

    Then add a configuration like video=HDMI-A-1:D video=LVDS-1:d to the APPEND line of /flash/syslinux.cfg

    Note 1) I recommend to use the run feature of the installation stick for testing. This allow changing of syslinux.cfg on a different machine.

    Note 2) If there are issues with the AMD driver of the old LE 9.2.6 kernel try LE 9.97.1



  • Thanks for your idea, I'll test it and post the result here. At first I'm turning on the TV first, then turning on the notebook. sorry for the delay in replying.desculpe a demora para responder.

  • hello guys, problem solved using this post.

    Protocol Zero
    January 31, 2019 at 10:02 PM