Change Accelerated Framebuffer Device

Technical Support
, ,
1

Hi,
I want to change the default Accelerated Framebuffer Device from fb0 to fb1.
I edited the /etc/X11/xorg.conf to:

Section "Device"
    Identifier  "i.MX Accelerated Framebuffer Device"
    Driver      "vivante"
    Option      "fbdev"     "/dev/fb1"
    Option      "vivante_fbdev" "/dev/fb1"
    Option      "HWcursor"  "false"
EndSection

Section "ServerFlags"
    Option "BlankTime"  "0"
    Option "StandbyTime"  "0"
    Option "SuspendTime"  "0"
    Option "OffTime"  "0"
EndSection

but after reboot I had something like this on my LCD (the LCD resolution is 800*600)
alt text
root@apalis-imx6:~# fbset -fb /dev/fb1

mode "240x320-60"
    # D: 38.251 MHz, H: 37.355 kHz, V: 59.863 Hz
    geometry 240 320 240 320 32
    timings 26143 672 32 17 283 80 4
    rgba 8/16,8/8,8/0,8/24
endmode

I manualy change the fbset:

root@apalis-imx6:~# fbset -fb /dev/fb1 -g 800 600 800 600 32
root@apalis-imx6:~# fbset -fb /dev/fb1

mode "800x600-60"
    # D: 38.251 MHz, H: 37.355 kHz, V: 59.863 Hz
    geometry 800 600 800 600 32
    timings 26143 112 32 17 3 80 4
    rgba 8/16,8/8,8/0,8/24
endmode

after that I had this:
alt text
my current vidargs is"

video=mxcfb2:dev=hdmi,800x600M@60,if=RGB24 video=mxcfb0:dev=ldb,bpp=32,800x600M@60,if=RGB666 ldb=sin0 fbmem=32M,24M

The current dmesg was attached here.

Thanks.

2

Greetings @prog!

Our display documentation states that the Vivante can only make use of the first framebuffer (/dev/fb0).

However, section 10.2.2 of the i.MX Graphics User Guide does mention something about rendering the desktop as an overlay configuring through fbset and xrandr so you can try that to tweak your resolution.