Multiple frambuffer/display support

[Amit]

Hi,

I was looking into multiple frambuffer options of pandroid kernel. Can
anybody tell me how it works?

Is it possible to configure kernel for 2 frame buffers and assign 1 FB
to HDMI and other to say DVI/LCD and get output on 2 devices?

I am booting 2 OSes parallely on Panda board and interested in taking
output from both OSes on different devices.


Thanks

[Giovanni]

How can you boot 2 OSes in parallel on panda board?

Which OSes?

Best regards,
giovanni

[Dechesne, Nicolas]

On Mon, Mar 28, 2011 at 2:03 PM, Amit <amitma...@gmail.com> wrote:

I was looking into multiple frambuffer options of pandroid kernel. Can
anybody tell me how it works?

you need to make sure your kernel is compiled with 2 FB (at least). The display subsystem on OMAP4 has at max 4 input pipes (at DSS). If you have N FBs (/dev/fbX), then there will be 4-N V4l2 pipes  (/dev/videoX). The split between FB and v4l2 pipes is not dynamic and needs to be done at compile time in the kernel.

Is it possible to configure kernel for 2 frame buffers and assign 1 FB
to HDMI and other to say DVI/LCD and get output on 2 devices?

once you have 2 FBs (/dev/fb0, /dev/fb1) you can configure each FB on a different display. If you have DVI and HDMI enabled then you can display 2 different content.

I am booting 2 OSes parallely on Panda board and interested in taking
output from both OSes on different devices.

we've done this on TI Blaze platform where Android is started in FB0, then we start X (ubuntu) on /dev/fb1. i guess you are doing something similar, e.g. 2 user space (or 2 instances of X) running on the *same* kernel.

[Amit]

On Mar 28, 10:49 pm, Giovanni <pino.o...@gmail.com> wrote:
> How can you boot 2 OSes in parallel on panda board?
>
> Which OSes?

We have virtualized android and linux solutions available for panda
board. So, booting multiple linux/android in parallel is already done.

I am just interested in having output of 2 androids or linuxs on 2
displays.

> Best regards,
> giovanni

[Mayuresh Janorkar]

Adding some more info to Nicolas's reply:

On Tue, Mar 29, 2011 at 2:57 AM, Dechesne, Nicolas <n-dec...@ti.com> wrote:
>
>
> On Mon, Mar 28, 2011 at 2:03 PM, Amit <amitma...@gmail.com> wrote:
>>
>> I was looking into multiple frambuffer options of pandroid kernel. Can
>> anybody tell me how it works?
>
> you need to make sure your kernel is compiled with 2 FB (at least). The
> display subsystem on OMAP4 has at max 4 input pipes (at DSS). If you have N
> FBs (/dev/fbX), then there will be 4-N V4l2 pipes  (/dev/videoX). The split
> between FB and v4l2 pipes is not dynamic and needs to be done at compile
> time in the kernel.
>>
>> Is it possible to configure kernel for 2 frame buffers and assign 1 FB
>> to HDMI and other to say DVI/LCD and get output on 2 devices?
>
> once you have 2 FBs (/dev/fb0, /dev/fb1) you can configure each FB on a
> different display. If you have DVI and HDMI enabled then you can display 2
> different content.

/dev/fb0 would be connected to overlay0 and /dev/fb1 would be
connected to overlay1.
You can change manager field of these overlays and get the required effect.

echo "0" > /sys/devices/platform/omapdss/overlay0/enabled
echo "lcd" > /sys/devices/platform/omapdss/overlay0/manager
echo "1" > /sys/devices/platform/omapdss/overlay0/enabled

For more info on sysfs entries for display please refer:
http://www.omappedia.org/wiki/Bootargs_for_enabling_display

-Thanks,
Mayuresh

[Giovanni]

On Mon, Mar 28, 2011 at 11:03 PM, Amit <amitma...@gmail.com> wrote:

On Mar 28, 10:49 pm, Giovanni <pino.o...@gmail.com> wrote:
> How can you boot 2 OSes in parallel on panda board?
>
> Which OSes?

We have virtualized android and linux solutions available for panda
board. So, booting multiple linux/android in parallel is already done.

Can you explain how you virtualized android and linux on the pandaboard?

 

[Amit]

On Mar 29, 11:48 am, Giovanni <pino.o...@gmail.com> wrote:

> On Mon, Mar 28, 2011 at 11:03 PM, Amit <amitmahaja...@gmail.com> wrote:
> > On Mar 28, 10:49 pm, Giovanni <pino.o...@gmail.com> wrote:
> > > How can you boot 2 OSes in parallel on panda board?
>
> > > Which OSes?
>
> > We have virtualized android and linux solutions available for panda
> > board. So, booting multiple linux/android in parallel is already done.
>
> Can you explain how you virtualized android and linux on the pandaboard?
>
>

For details check out our website at www.b-labs.com

[Amit Mahajan]

Very nice. Thanks for your expert comments. I will try your suggestions in a sometime and come back with more questions :).

FYI, when I say "I am running 2 OSes in parallel" i actually mean that I have 2 Operating systems running parallely on each core of omap4 :). Right now I am running android and linux in parallel and want to give one Display device to linux and one to android.

[Gregoire Gentil]

Here is a better approach of "virtualization" with an example on the
Beagleboard. The advantage is that it's fully native, you have no
performance loss:
http://www.alwaysinnovating.com/beagleboard/
http://www.youtube.com/watch?v=yseT4USH8SY (at 2:20)

Grégoire gentil
Founder Always Innovating
Follow us on twitter: http://twitter.com/#!/ai_info

On Mar 28, 11:02 pm, Amit Mahajan <amitmahaja...@gmail.com> wrote:
> On Tue, Mar 29, 2011 at 12:27 AM, Dechesne, Nicolas <n-deche...@ti.com>wrote:

[Dechesne, Nicolas]

On Tue, Mar 29, 2011 at 6:19 PM, Gregoire Gentil <greg...@gentil.com> wrote:

Here is a better approach of "virtualization" with an example on the
Beagleboard. The advantage is that it's fully native, you have no
performance loss:
http://www.alwaysinnovating.com/beagleboard/
http://www.youtube.com/watch?v=yseT4USH8SY (at 2:20)

are you 'just' starting multiple instances of X + Android user space, and switching between them (chvt?) or are you doing something different?

nicolas

[Gregoire Gentil]

We are running on the same kernel indeed. But then we have pushed the
concept a little bit further. Come and see us at ELC in San Francisco
on April 13th to get the internals!

http://events.linuxfoundation.org/events/embedded-linux-conference/gentil

Grégoire gentil
Founder Always Innovating
Follow us on twitter: http://twitter.com/#!/ai_info

On Mar 29, 10:04 am, "Dechesne, Nicolas" <n-deche...@ti.com> wrote:

> On Tue, Mar 29, 2011 at 6:19 PM, Gregoire Gentil <grego...@gentil.com>wrote:
>
> > Here is a better approach of "virtualization" with an example on the
> > Beagleboard. The advantage is that it's fully native, you have no
> > performance loss:
> >http://www.alwaysinnovating.com/beagleboard/

> >http://www.youtube.com/watch?v=yseT4USH8SY(at 2:20)

[Vladimir Pantelic]

Gregoire Gentil wrote:
> We are running on the same kernel indeed. But then we have pushed the
> concept a little bit further. Come and see us at ELC in San Francisco
> on April 13th to get the internals!
>
> http://events.linuxfoundation.org/events/embedded-linux-conference/gentil

I hope it will not be under NDA ;)

>
> Gr�goire gentil

[Amit]

On Mar 29, 8:04 pm, "Dechesne, Nicolas" <n-deche...@ti.com> wrote:

> On Tue, Mar 29, 2011 at 6:19 PM, Gregoire Gentil <grego...@gentil.com>wrote:
>
> > Here is a better approach of "virtualization" with an example on the
> > Beagleboard. The advantage is that it's fully native, you have no
> > performance loss:
> >http://www.alwaysinnovating.com/beagleboard/
> >http://www.youtube.com/watch?v=yseT4USH8SY(at 2:20)

FYI, By virtualization I meant running multiple kernels in parallel
not just parallel userspaces.

[Amit]

On Mar 29, 7:11 am, Mayuresh Janorkar <mayureshjanor...@gmail.com>
wrote:

> Adding some more info to Nicolas's reply:
>
>
>

> On Tue, Mar 29, 2011 at 2:57 AM, Dechesne, Nicolas <n-deche...@ti.com> wrote:

>
> > On Mon, Mar 28, 2011 at 2:03 PM, Amit <amitmahaja...@gmail.com> wrote:
>
> >> I was looking into multiple frambuffer options of pandroid kernel. Can
> >> anybody tell me how it works?
>
> > you need to make sure your kernel is compiled with 2 FB (at least). The
> > display subsystem on OMAP4 has at max 4 input pipes (at DSS). If you have N
> > FBs (/dev/fbX), then there will be 4-N V4l2 pipes  (/dev/videoX). The split
> > between FB and v4l2 pipes is not dynamic and needs to be done at compile
> > time in the kernel.
>
> >> Is it possible to configure kernel for 2 frame buffers and assign 1 FB
> >> to HDMI and other to say DVI/LCD and get output on 2 devices?
>
> > once you have 2 FBs (/dev/fb0, /dev/fb1) you can configure each FB on a
> > different display. If you have DVI and HDMI enabled then you can display 2
> > different content.
>
> /dev/fb0 would be connected to overlay0 and /dev/fb1 would be
> connected to overlay1.
> You can change manager field of these overlays and get the required effect.
>
> echo "0" > /sys/devices/platform/omapdss/overlay0/enabled
> echo "lcd" > /sys/devices/platform/omapdss/overlay0/manager
> echo "1" > /sys/devices/platform/omapdss/overlay0/enabled
>
> For more info on sysfs entries for display please refer:http://www.omappedia.org/wiki/Bootargs_for_enabling_display
>

I am compiling pandroid with 2 frambuffers by selecting
CONFIG_VIRTUAL_DISPLAY_SUPPORT
Number of FB =2

The pvr/sgx driver even doesnot compile with these options. I am using
L_27.8.2 pandroid. Are there any points for dual frame buffer setup?

[Amit]

>
> > Adding some more info to Nicolas's reply:
>
> > On Tue, Mar 29, 2011 at 2:57 AM, Dechesne, Nicolas <n-deche...@ti.com> wrote:
>
> > > On Mon, Mar 28, 2011 at 2:03 PM, Amit <amitmahaja...@gmail.com> wrote:
>

> > >> I was looking intomultipleframbuffer options of pandroid kernel. Can

> > >> anybody tell me how it works?
>
> > > you need to make sure your kernel is compiled with 2 FB (at least). The
> > > display subsystem on OMAP4 has at max 4 input pipes (at DSS). If you have N
> > > FBs (/dev/fbX), then there will be 4-N V4l2 pipes  (/dev/videoX). The split
> > > between FB and v4l2 pipes is not dynamic and needs to be done at compile
> > > time in the kernel.
>
> > >> Is it possible to configure kernel for 2 frame buffers and assign 1 FB
> > >> to HDMI and other to say DVI/LCD and get output on 2 devices?
>
> > > once you have 2 FBs (/dev/fb0, /dev/fb1) you can configure each FB on a
> > > different display. If you have DVI and HDMI enabled then you can display 2
> > > different content.
>
> > /dev/fb0 would be connected to overlay0 and /dev/fb1 would be
> > connected to overlay1.
> > You can change manager field of these overlays and get the required effect.
>
> > echo "0" > /sys/devices/platform/omapdss/overlay0/enabled
> > echo "lcd" > /sys/devices/platform/omapdss/overlay0/manager
> > echo "1" > /sys/devices/platform/omapdss/overlay0/enabled
>
> > For more info on sysfs entries for display please refer:http://www.omappedia.org/wiki/Bootargs_for_enabling_display
>
> I am compiling pandroid with 2 frambuffers by selecting
> CONFIG_VIRTUAL_DISPLAY_SUPPORT
> Number of FB =2
>
> The pvr/sgx driver even doesnot compile with these options. I am using
> L_27.8.2 pandroid. Are there any points for dual frame buffer setup?

Hi Nicolas/Mayur

Can you point me on some configuration file or symbols that needs to
be set for making dual framebuffer work properly.

Thanks

[karthi]

Giovanni <pino.otto@...> writes:

Hi,

May i know how you booted 2 OS's parallely on pandaboard. Kindly let me know the
steps involved in it?

Regards,
karthi