L4Android/L4Linux Beagleboard framebuffer and driver
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:
> 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.
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.
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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 .
But on some boards it doesn't.
The following steps have been tested only
on revision C4 beagle boards, but should
be valid for other revisions too.
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
3. From the l4 boot log, everything seems
fine, and fb-drv shows some nice messages.
Guys from the beagle board google code page ,
built a modified version of U-Boot, which includes
a boot logo and some extra dss initialisations.
Please download it .
The u-boot-f_revc_v3.bin file  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  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
OMAP3 beagleboard.org # nandecc sw
OMAP3 beagleboard.org # nand erase 80000 160000
OMAP3 beagleboard.org # nand write 80000000 80000 160000
Reboot. Now the framebuffer will be correctly configured by U-Boot.
 l4/pkg/drivers/lcd/src/lcd-omap3.c @ line 335
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