How to change display mode

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1

Hello,

I have a BeagleBoard-xM Rev A.

I installed Angström following the guide at
http://elinux.org/BeagleBoardBeginners#Writing_the_.C3.85ngstr.C3.B6m_image_into_the_SDcard_and_finally_booting_GNU.2FLinux

I get a message on the LCD "Frequency out of range: 47 kHz / 60 Hz.
Please change the display mode to 1280 x 1024 with 60Hz"

How can I change the display mode permanently?

NAND seems to be 0 Mib? Is it OK?

thanks...

2

Mustafa Aldemir wrote:

NAND seems to be 0 Mib? Is it OK?

the XM has no NAND

3

2011/9/23 Vladimir Pantelic <vladoman@gmail.com>

the XM has no NAND

thanks for your answer.

Do you know how to change the display mode?

4

2011/9/23 Mustafa Aldemir <mustafa@aldemir.net>

2011/9/23 Vladimir Pantelic <vladoman@gmail.com>

the XM has no NAND

thanks for your answer.

Do you know how to change the display mode?

Doesn’t anybody know how to change the display mode?

5

You can change the bootargs in u-boot.

Stop the boot process using a serial console and printenv the environment. You need to look for omapfb.mode and omapdss.def_disp in the bootargs (mmcargs). I think that currently the only supported display modes are dvi and tv out. By default, I think that omapfb.mode=dvi:640x480MR-16@60 and omapdss.def_disp=dvi. I haven’t tried it, but you can probably change the resolution and frame rate of the DVI using these bootargs. E.g. try setting omapfb.mode=dvi:1024x768R-16@60 and see what you get. It might work if these are parsed out.

Expect an lcd mode to be added soon to support the Beagleboard Toys 7” LCD panel.

John

6

You can make it permanent by writing your changed parameters to
uEnv.txt on the boot partition.

Cheers,
Akhil

7

Hello,

uEnv.txt doesn’t exist on my card. Should I write only “omapfb.mode=dvi:1024x768R-16@60” in it? Or, is there a special syntax for it?

best regards,

2011/9/27 Akhil <akhil.piplani@gmail.com>

8

you can add it in boot.cmd in bootargs section also, and after that you must convert it to boot.scr by mkimage…

2011/9/27 Mustafa Aldemir <mustafa@aldemir.net>

9

I'm not sure if that's necessary.
From his output I can see:
           " ** Unable to read "uEnv.txt" from mmc 0:1 ** "
So its a newer version looking for uEnv.txt instead of boot.scr.

Yes you can create that file yourself. Please also check which display
modes are actually available for your setup.

I suggest doing this step-by-step.

1. Stop the boot process during the countdown.
2. use printenv to see your current parameter values.
3. Use setenv <param-name> <param-value>. Notice the lack of "=".
4. Type boot to boot and test if it works.

Once you get it to work:
Add a line to uEnv.txt (create if necessary) with <param-name> <param-

. Still no "=".

Cheers,
Akhil

10

In uEnv.txt I think thay you can use an "=". So you can copy the
output of the default printenv (default Uboot environment) into
uEnv.txt, put that into the 'boot' partition of the microSD card, and
you get a set of environment vars that you can configure by modifying
the text file.

11

I stand corrected.

12

for people having the same problem in future:

setenv dvimode 1280x1024MR-24@60
saveenv
boot

solved my problem.

2011/9/27 Akhil <akhil.piplani@gmail.com>

13

Does it persist after you reboot?

14

after powering it up again this morning, I saw it didn’t persist :((

I created uEnv.txt on the boot partition and wrote:

dvimode=1280x1024MR-24@60
uenvcmd=run loaduimage; run mmcboot

now it seems to be OK after rebooting.

2011/10/10 Akhil <akhil.piplani@gmail.com>