L4Android/L4Linux Beagleboard framebuffer and driver

Giorgio Wicklein giowckln at googlemail.com
Fri Oct 7 13:36:47 CEST 2011


On Tue, Oct 04, 2011 at 11:12:39PM +0200, Adam Lackorzynski wrote:
> Hi,
> 
> On Tue Oct 04, 2011 at 14:16:10 +0200, Giorgio Wicklein wrote:
> > Maybe a newer version of U-Boot solves this?
> 
> Hmm, if it's already doing some graphics, I do not see what a different
> u-boot would be doing different. But maybe it's worth a try.
> 
> Adam

Hi,

now the framebuffer gets correctly configured and initialized by u-boot.
The spectrum example and L4Android can use the fb.
Seems good so far.

I wrote a small guide on what I did, in case someone encounter the same issue.
(See attachment)
-------------- next part --------------
L4 Framebuffer fix for BeagleBoard
==================================

    LCD should "just work" on BeagleBoard,
    since the L4 framebuffer driver just
    hooks the initial dss configuration,
    done by U-Boot [1].

    But on some boards it doesn't.


Notice
======
    The following steps have been tested only
    on revision C4 beagle boards, but should
    be valid for other revisions too.


Symptoms
========
    1. When the board is powered on,
    an gradient-like splash screen,
    with colors from orange to yellow,
    is displayed on your LCD display.

    2. The framebuffer doesn't work
    on L4Linux/L4Android or on the L4 spectrum
    example.

    3. From the l4 boot log, everything seems
    fine, and fb-drv shows some nice messages.


U-Boot
=======
    Guys from the beagle board google code page [2],
    built a modified version of U-Boot, which includes
    a boot logo and some extra dss initialisations.

    Please download it [3].
    The u-boot-f_revc_v3.bin file [4] is known to work on
    a bb rev. C4.

    Once downloaded, replace the current u-boot in use,
    with the new one. Please see the beagle board page on
    elinux.org [5] for instructions.
    Those are reported in the next section.


NAND flashing U-Boot
====================
    In order to replace the u-boot binary on your
    NAND flash, follow these steps:

    OMAP3 beagleboard.org # mmc init (or mmcinit)
    OMAP3 beagleboard.org # fatload mmc 0:1 80000000 u-boot.bin
    OMAP3 beagleboard.org # nand unlock
        (Note - if you are using a more recent version of U-Boot,
        nand unlock is missing simply skip this step.  i.e. U-boot
        2009.08)
    OMAP3 beagleboard.org # nandecc sw
    OMAP3 beagleboard.org # nand erase 80000 160000
    OMAP3 beagleboard.org # nand write 80000000 80000 160000


Conclusion
==========
    Reboot. Now the framebuffer will be correctly configured by U-Boot.


[1] l4/pkg/drivers/lcd/src/lcd-omap3.c @ line 335
[2] http://code.google.com/p/beagleboard/
[3] http://code.google.com/p/beagleboard/downloads/list
[4] http://beagleboard.googlecode.com/files/u-boot-f_revc_v3.bin
[5] http://elinux.org/BeagleBoardNAND#U-Boot


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