Turning on the computer, monitor, keyboard/mouse in any order

Mood-Indigo · 2025-01-22 15:14:54

I have 2 computers sharing a monitor and keyboard/mouse via a KVM switch. Many times I turn on or reboot one computer (A) while the KVM is connecting the monitor to the other computer (B) where I am doing some work. When I switch to computer A after a minute or so, I get a blank screen instead of the login screen. Computer A is up & running since I can ssh into A from B, but I cannot use the desktop on A, until I reboot it with the KVM pointing to it.

This scenario also happens with my LibreELEC box connected to my TV. Again quite often, I turn on the Kodi box before turning on the TV and get a blank screen. However, LibreELEC provides a script (see https://wiki.libreelec.tv/configuration/edid) that fixes this issue. After running the script, I can now turn on the devices (TV, sound, Kodi) in any order.

Is there something similar on Arch? I would like my Arch system to boot up without the monitor and keyboard/mouse and still function normally when the monitor and keyboard/mouse are attached.

twelveeighty · 2025-01-22 18:49:32

I think you have two options: 1) find a way to re-trigger the device detection on switching the KVM, or probably a much better option, force the Xorg/libinput settings through configuration and don't rely on auto-detection at all.

seth · 2025-01-22 22:02:55

The devices are probably detected but assuming this is X11 the new output will not necessarily be automatically activated => https://aur.archlinux.org/packages/x-on-resize
We'll however need to know more about the concerned environment, some GUI stuff might flat out crash if there's no monitor…

Mood-Indigo · 2025-01-23 04:19:57

twelveeighty wrote:

I think you have two options: 1) find a way to re-trigger the device detection on switching the KVM, or probably a much better option, force the Xorg/libinput settings through configuration and don't rely on auto-detection at all.

I believe the shell script that I ran on my LibreELEC box configured the kernel boot sequence. The script reads the EDID off the TV, saves the EDID data insides an initrd file, and modifies the boot flags to load that ram disk. In other words, I think the script hardcoded that particular TV into the boot sequence. If I were to change my TV or even re-plug the HDMI cable into the second HDMI socket of the LE box, I would need to re-run the script.

I cannot use the script on Arch because the boot files on Arch and LibreELEC are different. And I don't know how to modify the script for Arch since I have no clue on how to configure the kernel boot sequence. I was hoping someone better can create a similar package for Arch

seth · 2025-01-23 08:58:10

That approach won't be much different on arch, https://wiki.archlinux.org/title/Kernel … s_and_EDID

I have no clue on how to configure the kernel boot sequence

If you're actually running arch and not some derivate you'll know what bootloader you use and that's where you alter the commandline, check the sublinks of the previous one.

Arch Linux

#1 2025-01-22 15:14:54

Turning on the computer, monitor, keyboard/mouse in any order

#2 2025-01-22 18:49:32

Re: Turning on the computer, monitor, keyboard/mouse in any order

#3 2025-01-22 22:02:55

Re: Turning on the computer, monitor, keyboard/mouse in any order

#4 2025-01-23 04:19:57

Re: Turning on the computer, monitor, keyboard/mouse in any order

#5 2025-01-23 08:58:10

Re: Turning on the computer, monitor, keyboard/mouse in any order

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