How set custom screen resolution?

giaur500 · Published in 2015-10-29 07:14:52

How can I change screen resolution to, for example 1680x1050 or 1280x1024. Can I change resolution on running Debian system?

bronco · Published in 2015-11-18 22:14:52

Edited by bronco at 2015-11-18 22:16

Changing resolution on a SBC is totally unrelated to the distro you're running but part of the hardware initialisation:

http://linux-sunxi.org/Display#Changing_resolution

Do you use H3 or A20? In case of the former would be interesting whether the a10disp tool works or not ("3.4.43 or later" and H3 will stay on 3.4.39 for the next months or even forever). In case a10disp isn't working you've to hardcode the resolution in the fex file. Also outlined in the link above: http://linux-sunxi.org/Display#script.bin.2Ffex_file

tmclane · Published in 2015-11-18 23:58:48

How do you hardcode a resolution that isn't listed in the driver itself?
Is that possible?

Can you provide a working example?

bronco · Published in 2015-11-19 00:29:22

tmclane replied at 2015-11-18 23:58
How do you hardcode a resolution that isn't listed in the driver itself?
Is that possible?

Regarding LVDS or HDMI? The former is stuff for script.bin and regarding the latter: as far as I know you're somewhat lost regarding early boot stages (both u-boot -- where situation differs between mainline u-boot and the outdated sunxi-u-boot -- and early boot in Linux). Later it should work identical to A10/A20: By using fbset and tweaking settings until they fit: I made the mistake to try to access a 7" display with 1024x600 pixels through HDMI in the past: http://forum.lemaker.org/thread-15430-1-1.html (can't remember exactly how I got the exact values. I just thought: post them somewhere so others might find them and do not have to waste hours again)

tmclane · Published in 2015-11-19 03:57:03

Edited by tmclane at 2015-11-19 04:30

I was hoping to get one of these working:

http://www.ebay.com/itm/12176709 ... =STRK%3AMEBIDX%3AIT

It also runs using 1024x600 over HDMI.
The fbset command on the forum you linked to doesn't cause any GUI to appear for me. Does that mean it is not quite correct?
Do you leave the script.bin alone (which is set to 720p by default) when this command is run?

tmclane · Published in 2015-11-19 07:02:18

It works fine with a Raspberry Pi B with the following settings:

hdmi_group=2
hdmi_mode=1
hdmi_mode=87
hdmi_cvt=1024 600 60 3 0 0 0

I can't figure out how to map the hdmi_cvt to the proper settings.  I have attempted various settings in the /etc/fb.modes file but none have provided me with more than a black screen.  Do I need to also do xorg.conf configuration for X to come up?  I don't care if the console doesn't work.

I came across the following post which leads me to think I may be on the right track:

http://forum.lemaker.org/thread-14087-1-1.html

bronco · Published in 2015-11-19 20:37:06

tmclane replied at 2015-11-19 07:02
It works fine with a Raspberry Pi B with the following settings:

hdmi_group=2

Raspberry Pi is totally different. There you initialize the VideoCore GPU prior to the ARM cores. On my system the fbset approach worked (all forum posts you mention are from me).

But I don't remember whether I did something special regarding xorg.conf -- tried to have a look since I visited the customer right now. But all xorg.conf related stuff has gone since the system runs headless now (apt-get autoremove --purge) and due to a backup retention time of 90 days there's nothing either.

tmclane · Published in 2015-11-22 01:45:57

I understand the raspberry is different.
When the fbset command is run and works does the terminal show up immediately?

Or do I have to start X11 and then the video turns on?
In other words what effect should a working fbset command have on the system?
I couldn't tell if I had gotten it right.

tmclane · Published in 2015-11-22 01:55:14

I found that the panel came with a working bananapi image for 1024x600 resolution but using the relevant portion of the fex file didn't seem to work on my orange pi plus. I understand it is also an H3 board.

bronco · Published in 2015-11-22 02:24:07

tmclane replied at 2015-11-22 01:45
I understand the raspberry is different.
When the fbset command is run and works does the terminal ...

On the Lamobo-R1 where I did that it works as follows: I defined 720p in boot.cmd (comparable to uEnv.txt) therefore the system comes up with 1280x720 pixels and when rc.local will be executed switches to 1024x600 pixel instead when the fbset has been called. No X11 started, plain console (but IIRC after startx the settings were stuck)
On that board I use Armbian with one of the latest community kernels (3.4.108 or above). Maybe that makes the difference.