Questions/possible bugs about JDK 1.8.0 + OpenJFK on the PI 2

David Hill David.Hill at
Thu Mar 26 18:59:04 UTC 2015

On 3/26/15, 2:40 PM, Fabrizio Giudici wrote:
> On Wed, 25 Mar 2015 21:04:28 +0100, David Hill <David.Hill at> wrote:
>> On 3/25/15, 3:28 PM, Fabrizio Giudici wrote:
>> Two possibilities -
>> Did you up the allocated vram ? (I think this might not be a factor on newer Raspbians, they were going to a dynamic split).
>> Does X11 fill the full screen when it runs  ?
>> It would be interesting to know what FX thinks the screen is sized at, -Dprism.verbose=true
> Ok, I think I got it. Looking at /boot/config.txt I saw:
    good to hear you are further along.

If I recall the code initialization correctly, there is not any options for us to do much when opening the framebuffer channel. It is my belief that all of that is done in the kernel, which is why tinkering with that conf file makes things work.

> # NOOBS Auto-generated Settings:
> hdmi_force_hotplug=1
> config_hdmi_boost=4
> overscan_left=24
> overscan_right=24
> overscan_top=16
> overscan_bottom=16
> disable_overscan=1
> gpu_mem=256
> I commented out all the overscan_* and set disable_overscan=0. Launching startx, I see that the graphics covers the full screen (some pixels are clipped out, so X11 would really require some overscan, even though a smaller amount). But now JavaFX covers the full screen. Also for JavaFX there are some pixels clipped out. This is not a problem for me: I think that it's up to the JavaFX application to correct for overscan, by simply putting some space around the true contents.
> So, the thing now is fine for me. But I think that there is a real bug: JavaFX is not correctly computing the screen area when there's that overscan settings. It's probably a low priority one - maybe it would just make sense to warn people about it.
> The mouse is ok, it was probably a connection fault. The keyboard navigation of buttons is still not working - still investigating.

David Hill<David.Hill at>
Java Embedded Development

"A man's feet should be planted in his country, but his eyes should survey the world."
-- George Santayana (1863 - 1952)

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