Unable to read the Pandaboard framebuffer content using mmap()

[Martin Siegumfeldt]

Hi,

I am trying to read the framebuffer of the Pandaboard using ICS 4.0.3,
however so far without success. It turns out that the screencap
application (https://github.com/android/platform_frameworks_base/blob/
master/cmds/screencap/screencap.cpp) is also not able to read it (when
forced to use mmap() rather than the "ScreenshotClient"). The IOCTL
call return valid dimenional information and mmap() seemingly returns
a valid pointer, however the generated png file is simply generated
transparent? I was considering whether at all it is possible to read
the framebuffer of the OMAPDSS driver - it is after all not a
traditional framebuffer driver? However the hardware composer module
(part of https://dl.google.com/dl/android/aosp/imgtec-panda-iml74k-cfb7bdad.tgz)
uses mmap() in the device_open() hence I assume it is possible?

Any ideas of how to fix this is highly appreciated.

Thanks,
Martin

[Jayabharath Goluguri]

Related issue is discussed here http://e2e.ti.com/support/omap/f/849/t/163304.aspx

--Jay

On Feb 20, 8:29 am, Martin Siegumfeldt <martin.siegumfe...@ixonos.com>
wrote:

> Hi,
>
> I am trying to read the framebuffer of the Pandaboard using ICS 4.0.3,
> however so far without success. It turns out that the screencap
> application (https://github.com/android/platform_frameworks_base/blob/
> master/cmds/screencap/screencap.cpp) is also not able to read it (when
> forced to use mmap() rather than the "ScreenshotClient"). The IOCTL
> call return valid dimenional information and mmap() seemingly returns
> a valid pointer, however the generated png file is simply generated
> transparent? I was considering whether at all it is possible to read
> the framebuffer of the OMAPDSS driver - it is after all not a
> traditional framebuffer driver? However the hardware composer module

> (part ofhttps://dl.google.com/dl/android/aosp/imgtec-panda-iml74k-cfb7bdad.tgz)