is virtual display possible with fbturbo

[František Horínek]

Hi,

 

I am having problem with overscan on orangepipc on my car display.

 

https://goo.gl/photos/19v3Ji2cAUMsLwoV6

 

Left border is cropped by 32 pixels and bottom is cropped by 52px. Resolution is 800x480 configured with h3disp -m 31.

I am outputing video using HDMI-to-VGA reduction and then I transform VGA signal to RGBS using two XOR gates (so the car display understand the signal). 

Running self-build Armbian with ubuntu xenail on legacy kernel (3.4.113-sun8i).

 

I want to crop or scale my desktop so it will fit the screen.

 

I tried so far

• xrandr --transform (it seems that it is not supported)
• set env in uboot to enable overscan_x and y (works only in uboot, xserver does not start)
• adding .conf to xorg.conf.d:

Section "Screen"
  Identifier "MyScreen"
  Device "Allwinner A10/A13 FBDEV"
  Monitor "Monitor0"
  DefaultDepth 24


  SubSection "Display"
    Depth 24
    Virtual 768 524
    ViewPort 32 56
    Modes "800x480"
  EndSubSection
EndSection

But it seems that xserver is ignoring the subsection. Maybe fbturbo is unable to use virtual displays?

 

 

Is there any way how to rescale the desktop to fit the screen?

 

Thank you

 

Fero

 

 

 

[František Horínek]

little update I mange to squeeze screen to 768x424 using modeline, the real output is still 800x480 configured with h3disp -m 31. 

root@orangepipc:~# cat /etc/X11/xorg.conf.d/*
Section "Monitor"
	Identifier		"Monitor0"
	Option			"DPMS" "false"
	Option			"PreferredMode" "800x480"
	Modeline "800x480" 24.16 800 808 888 976 480 481 484 495 -HSync +Vsync
	Modeline "768x424" 24.92 768 816 888 944 424 425 428 440 -HSync +Vsync
EndSection

Section "Screen"
	Identifier "MyScreen"
	Device	"Allwinner A10/A13 FBDEV"
	Monitor	"Monitor0"
	DefaultDepth 24

	SubSection "Display"
		Depth	24
		Virtual 768 424
		ViewPort 32 0
		Modes "768x424" "800x480" 
	EndSubSection

Now I only need to move it to the right by 32px