Change resolution in HDMI monitor rpi3b+ aarch64

#1

I have installed the arm64 (aarch64) image on a raspberrypi 3b+. My problem is that I cannot change the screen resolution to something sensible. My monitor is an HP LA2405wg and I am attaching it through HDMI. By default the resolution is 656x416. There are no other options available in the Display > Monitor Preferences menu. I have tried changing some options in the config.txt file but I couldn't make it work. I am trying to find the correct options through the tvservice command as mentioned in this article. I see from this forum post that another user was able to use tvservice command. However I am getting:

$ tvservice -s
tvservice: command not found

Why would this be happening?

P.S. I tried to fix the problem by enabling some config.txt options such as hdmi_force_hotplug=1 but I couldn't make it work.

#2

sudo find / -name tvservice

that should give you the full path where this app is, then use the full path to execute it.
You may find it in /opt/vc/bin/

#3

I have already tried that (and tried again after your post), nothing was found. In /opt there is only a folder named pigpio.

#4

from this link https://www.raspberrypi.org/forums/viewtopic.php?t=113602

cd /tmp
git clone http://github.com/raspberrypi/userland
cd userland
./buildme

That will put tvservice in /opt/vc/bin you may want to create a link from there to /usr/bin/tvservice
sudo ln -s /opt/vc/bin/tvservice /usr/bin/tvservice

#5

I tried that. Needed to install some packages first

sudo apt install git cmake make build-essential

before I could start building. However the build failed with an error at ~11%. Don't have the skills to debug it I 'm afraid.

However by looking at the project's readme it said that arm64 is not supported yet. So I decided to try the armhf image - which is the recommended one anyway. Luckily that image included tvservice and I was able to set up a custom resolution through the raspi-config advanced settings.

#6

There's a lot to be said for reading the release notes carefully before doing the download. They gave me the reasons for using the armhf package, as I wanted to be able to use raspi-config and tvservice.
Derek

#7

raspi-config works on both armhf and arm64. tvservice working only on armhf was not mentioned anywhere on the ubuntu mate page as far as I could tell. That said there were a lot of other features that were armhf only and arm64 was clearly marked as experimental. I used it because I wanted to try it. I actually downlowaded both images knowing I would likely go to the more stable image.

#8

The ONLY way to change screen resolution on the Pi is at boot time.
It CANNOT be changed on a running system, because it is determined by the Video Core.

Regardless of which tool you use the change needs to be in config.txt (or the command line).