proper omapfb settings for pico projector and angstrom?

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1

what are the proper kernel command line video settings for a pico
projector and the latest binary build of angstrom? i thought it would
be something straightforward, then i found this page of beagleboard
IRC logs:

  http://www.beagleboard.org/irclogs/index.php?date=2009-02-02

where koen claims that this is what he uses:

console=ttyS2,115200n8 root=/dev/mmcblk0p2 rw rootfstype=ext3 rootwait
  video=omapfb:vram:2M,vram:4M,mode:640x480@60
  omapfb.video_mode=640x480MR-16@60 omapfb.vram=4M,4M,4M

does that look about right? can it be simplified just a bit? i'm
guessing i better read up on DSS2.

rday

2

Hi Robert,

This really depends on the kernel version, and 2.6.29 just went into
2009/stable...

2.6.28 : omap-dss.def_disp=lcd omapfb.video_mode=640x480MR-16@60

2.6.29 : omapfb.mode=dvi:640x480MR-16@60

Regards,

3

to start out simple, i'm using the most recent pre-built uImage
here:

    http://www.angstrom-distribution.org/demo/beagleboard/

and since that's based on 2.6.28, i guess i'll go with the first
option.

rday

p.s. i actually googled madly for about half an hour looking for the
answer to that, and i couldn't find it. it seemed like such a simple
question, but googling on various combinations of beagleboard,
angstrom, pico, omapfb and others never showed me *that*.

4

just to clarify, *before* 2.6.28 was what i see referred to as
"DSS1"? then, if you start reading here:

http://elinux.org/BeagleBoardFAQ#Pico_Video_Projector_Kit_.28PVPK.29

it appears that 2.6.28 represents where DSS2 kicks in, right? and
that applies to the currently available 2.6.28-r17 binary angstrom
image.

once we get to 2.6.29, though, things change yet *again*? is that
still what one would call DSS2?

rday

5

Yeah, the omapfb settings aren't really documented anywhere except in
the source. But considering it's changed syntax in every kernel
version since 2.6.26 i don't think anyone wants to put those settings
'in stone' anywhere.

I do have the syntax shown here:
http://elinux.org/BeagleBoardUbuntu#Beagleboard:_Setup_U-boot_for_boot
http://elinux.org/BeagleBoardDebian#Install_complete

Regards,

6

Yes 2.6.28 introduced the initial DSS2 changes (aka rewrite of DSS),
however they were extended even more for 2.6.29. (and probably more
for 2.6.30) Before they get mainlined...

Regards,

7

It changed syntax a bit more often, but I try to group such changes with kernel releases, so that in a single kernel version you get the same interface. For 2.6.29 I cheated a bit, since the sysfs interface received some additions (e.g. overlay transparency, vrfb, etc).
It also helps a lot to talk to Tomi and Hardik every now and then to check about pending changes :slight_smile:

regards,

Koen