BBxM Ubuntu 14.4 HDMI problem

Hi,

I’m new to this world and to this forum so I don’t know is it the right place for the question.
I’ve been trying to install ubuntu on my beagleboard xM for a few days now and still no success. First I tried to install it using windows 7 following this tutorial:
http://www.elinux.org/Beagleboard:BeagleBoard-xM
and I’ve managed to successfully install demo OS that is shipping with the Beagleboard xM, but when I tried to do the same with Ubuntu 14.4 I ran into a problem. Installation on the SD card went without a glitch but when I tried to boot it from BB xM all I got was a brief orange screen and than nothing, TV was signaling “No signal” but in a very uncommon fashion (like he is getting something but can’t interpret it). Next interesting thing was that my keyboard worked, when I pressed CTR+ALT+DEL it restarted. I looked all over the internet but couldn’t find a solution.

Ubuntu .img I got from here: https://rcn-ee.net/deb/microsd/trusty/

Can someone help me with that? And can someone point me to some older Ubuntu .img files (not .tar)?

Thanks

Sounds like edid detection of your monitor failed. Do you have a
serial connection avaiable to debug?

In /boot/uEnv.txt you can force a resolution via:

cmdline=video=DVI-D-1-1:1024x768@60e

Regards,

Opps, extra "-1" in there:

cmdline=video=DVI-D-1:1024x768@60e

Regards,

Thanks! That worked like a charm

this seems like a bug to me. it would make sense to have a sensible VESA fallback when the EDID cannot be grokked.

/iaw

Sure, you got a patch for that?

Regards,

maybe eventually.

it’s not so easy to help. this is only a hobby for me, when I have time.

I installed ub 14.04 and wanted to give others some added/better hints on elinux on

http://elinux.org/Beagleboard:Updating_The_Software

but this seems to be locked down. if wikipedia is open enough to allow logged-in individuals to make updates, maybe this one should too?!

eventually, I may want to figure out how would handle simple patches.

regards,

/iaw

http://elinux.org/Beagleboard:<xyz> are locked due to issues in the past.

If it's something specific to "ubuntu" for "beagle products" look at:

http://elinux.org/BeagleBoardUbuntu

Which covers all beagle products, other then section 4 which is
automaticly edited every month via a release script.

Regards,

​thanks, robert. if there was trouble before, then it makes sense that open editing was closed down. who does one send suggestions (experiences) to? are they even wanted? the good news is that everything posted here also goes into the google store when people are searching.

I know for sure now that my Samsung Syncmaster 213T from 2005 is a big part of the problem. it comes up black at boot, and does not get any better later. I tried replacing the default “quiet” in uEnv.txt with “verbose” and eventually with nothing. I also tried it with various video= command switches. I tried everything from 800x600@60e to 1600x1200@60e, but the samsung and bbb just don’t seem to get along.

I then tried a newer low-end DELL monitor (same cable). the hdmi also comes up black at boot. I am guessing that, because the bbb hdmi port is not dedicated, it first needs to be switched on somewhere during the boot process. fortunately, the DELL monitor eventually does come up visibly for the login prompt.

I am logged into the bbb via usb-ssh right now. grepping for hdmi​(or edid) ​
tells me about pinmux mode and davinci sound, but nothing​ interesting about where the hdmi went wrong.

  • is there a command line utility over ssh to experiment instantaneously with setting different video modes on the hdmi port?
    fbset -xres … -yres … makes no difference on the physical display, although “fbset -s” tells me that it thinks it executed…

  • or a way to get more debugging information about hdmi, possibly into dmesg? even learning whether the bbb thinks that a connection over hdmi has been established would be useful. (together, these two would make it easy for a user to script a fallback.) /proc/fb only contains “0”.

​/iaw