Video-detection: wrong resolution on boot from dvd

**badger99** · 03-05-2011, 11:40 AM

New to knoppix, I am runing 6.4.4 from a dvd. On boot from the CD, knopix gets the monitor resolution wrong (although it does detect both my monitors) but the screens are covered in garbage.

How can I resolve/work around this?

**Forester** · 03-06-2011, 10:45 AM

Hi and welcome to the forums badger99.

Thanks for telling us which version of Knoppix you are using. You would be surprised how many people don't. I use the DVD myself.

You say you are new to Knoppix so I guess this isn't something that used to work with some older version of Knoppix. Have you any previous experience of Linux ?

Can you tell me if you are using a laptop with an external monitor or this a desktop PC ? If you use just one screen is it still covered with garbage ? A laptop will have some function key that cycles through internal / external / both screens. Try each and reboot each time to see if that makes a difference.

You say the resolution is wrong. Is it lower than you expected or higher than you expected ?

In what way does the screen appear to be covered with garbage ? I know it sounds a silly question but are lots of different ways the screen could appear as garbage.

When does the screen become garbage ? When you boot the first screen shows the Knoppix logo and has a boot: prompt at the bottom. This is OK ? After a second or two the screen clears and then you start to get text message showing the progress of the boot, including a wide green bar. Is this OK ? Part way through, the text appears to get smaller. Is it still OK ? Then you get the Knoppix logo again and a woman's voice (if your audio is turned up), then finally you get the desktop without needing to log in. Is it just this last that is garbage ?

If you press ctrl-alt-F1 (all three keys at the same time) you should get back to the console showing the text that you could see during boot. If that is OK, please type in the following:

Code:

 lspci

look at the output for any lines that say something like VGA compatible controller. Could you notes these lines down and write them up in your next post. At the beginning of the each line is a 'number'. For me it is 00:02.0. Can you type in:

Code:

 lspci -v -s <number>

Can you note down the last line output and put that in your next post too. For me that is:

Code:

 Kernel driver in use: i915

If you know enough Linux to know what syslog is, try ctrl-alt-F12 to get the tty console with syslog output and see if anything there looks suspicious. For me it is almost all Network Manager stuff that is irrelevant.

Back to ctrl-atl-F1, could you type in:

Code:

 fgrep '(EE)' /var/log/Xorg.0.log

This shows you any errors the Xserver has encountered and they may be significant. The Xserver is the software that drives your screens. I get some error messages about the Synpatics TouchPad that are not important. Please copy down any others and include them in your post (at least the first and last two or three if there are lots). If you type in:

Code:

less /var/log/Xorg.0.log

you can page through the log. It's long and won't make a lot of sense. Part way down you will come across something like:

Code:

EDID (in hex):
  serveral lines with lots of hex numbers
EDID vendor "CMO", prod id 5522

Should you find this in there twice since you have two screens. Note down the last line each time. This tell us what your monitors are. Following this is a load of stuff about modelines. This is the Xserver trying to make up screen resolutions that your graphics chip and your monitor both support. Lines that start "Not using default mode" are bad for some reason, while lines that start with Modeline are good. Are the screen resolutions you expected good ?

A little below that there are several lines that all start with Output. I have:

Code:

 Output LVDS1 using initial mode 1366x768

which tells me I'm using the laptop's internal screen (only) at resolution 1366x768. Could you also copy down these lines and include them in your reply.

If the garbage is so bad you can't even see the text on the console I've been taking about, do not despair. Your PC / Laptop document will tell us something about the graphics chip. If it a reasonably new machine, the keywords to look out for at Nvidia and ATI Radeon.

Lastly, do you know what a 'cheatcode' is ? You can use these at the initial boot: prompt, If you type in:

Code:

less /mnt-system/KNOPPIX/knoppix-cheatcode.txt

you can page through the cheatcodes. There is a bunch under ### Graphics ### that allow most people to workaround screen problems. The questions I've asked may help decide which, if any, you might use but you could also might try a 'trial and error' approach.

**badger99** · 03-06-2011, 08:10 PM

Forester,

Thanks for your reply.

First, let me backup and say why I wanted to use Knoppix. I am installing ubuntu 10.04.2 64 bit on a new pc. The first install went OK, but I'd picked the wrong keyboard layout, did not know how to change it, and decided to re-install and get it right.

Unfortunately the second install did not complete. Ubiquity, the package containing the ub installer wizard stopped the process during partitioning, saying 'No root filesystem is defined'. At that point, the first install would not boot anymore, and the installer would not run.

Reasoning that I may have trashed the new HD formatting (I may have powered down during an install attempt), I figured I'd try to use knoppix to see what condition the HD is in. I dont know how it was formatted and partitioned when I got it from the folks that assembled the PC.

Now to answer your questions about knoppix, because I really want to be able to use it as a sysadmin and repair tool from now on, and have been putting off this learning for too many years.

==================================

1. I have some experience with linux sys-admin, I've been using redhat and now ubuntu for about 3 years, but I am really a java/osgi developer and data modeler by trade.

2. The new pc is a desktop, built around a Gigabyte GA-890XA-UD3 motherboard.

3. The resolution looks wrong, in that the screens show lines of pixels that do not line up. The problem only shows up when knoppix enters runlevel 5. Level 4 is legible (small letters) and usable. Both screens show the same stuff on level 4 (a shell) and 5 (garbage). Initially the garbage is static, then after a while it becomes dynamic, which I take to be the output of a screensaver.

4. Command lspci -v -s 01:00.0 shows the kernel in use to be nouveau.

5. Command fgrep '(EE)' /var/log/Xorg.0.log yields three lines:

(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
[ 214.008] (EE) NOUVEAU(0): Error creating GPU channel: -19
[ 214.008] (EE) NOUVEAU(0): Error initialising acceleraion. Falling back to NoAccel

6. command fgrep 'EDID' /vat/log/Xorg.0.log yields:

[ 213.3521] (II) NOUVEAU(0): EDID for output DVI-I-1
[ 213.3521] (II) NOUVEAU(0): EDID Version: 1.3
[ 213.3521] (II) NOUVEAU(0): EDID (in hex):
[ 213.3521] (II) NOUVEAU(0): EDID vendor "GSM", prod id 20105
[ 213.3521] (II) NOUVEAU(0): Using EDID range info for horizontal sync
[ 213.3521] (II) NOUVEAU(0): Using EDID range info for vertical refresh
[ 213.3521] (II) NOUVEAU(0): EDID for output DVI-I-2
[ 213.3521] (II) NOUVEAU(0): EDID Version: 1.3
[ 213.3521] (II) NOUVEAU(0): EDID (in hex):
[ 213.3521] (II) NOUVEAU(0): EDID vendor "GSM", prod id 20105
[ 213.3521] (II) NOUVEAU(0): EDID vendor "GSM", prod id 20105

7. I have read the stuff on cheatcodes, but have not tried to use them yet.

===================================

After answering the above questions, I tried the boot command

knoppix screen=1680x1050, but still got garbage in level 5.

Hope the above helps you help me.

**utu** · 03-07-2011, 02:20 AM

@badger99

Welcome to the forum, badger99.
You are in good hands with Professor Forester.

One additional thing you might want to try is to see if the lxrandr
program built-in to Knoppix 6.4 offers any help in your situation.

This program is accessible via the command line as simply lxrandr,
or via the LXDE main menu at Preferences/Monitor settings.
Mine gives me five settings, but it was ok on install, so I didn't need it.

I'm wondering if it'll be confused with TWO monitors.

Lots of luck, and let us know how it's going.

**badger99** · 03-07-2011, 04:21 AM

Utu, thanks for your note.

Tried lxrandr, but got the message 'Gtk-WARNING **: cannot open display:

**Forester** · 03-07-2011, 03:35 PM

Thank you for the information badger99. I think two of us have a serious timezone mismatch. utu is too kind. I've never had a messed screen under Knoppix so this is new ground for me too.

The information you've provided tells me you've a modern machine with two DVI outputs for video and two 'wide-screen' monitors of the same make and model. Not quite what I'd imagined from your first post but then you did not say very much.

I think you should be able to fix this with cheat codes. Knoppix is famous for its hardware recognition. IMHO, if your hardware is too new for Knoppix to recognise then mainline Linux distributions have no chance.

The X org video driver (not Linux kernel) you've got loaded the nouveau driver. I believe this is a new, open source, alternative to the proprietary nvidia driver. I suspect nouveau is 'still in development' as they say. It looks like it has problems initialising the graphics acceleration on your graphics card. The garbage you describe sounds like a vertical or horizontal refresh issue.

I'll take your word for it that you've a graphics card in there and a fall back graphics chip on your mother board. To switch between the two I'd guess you'd need to change a BIOS setting but that should not be necessary.

The first thing to try is the proprietary nvidia driver. Try the bootline:

Code:

knoppix xmodule=nv

If that looks good, check the X server log for errors (EE) and warnings (WW) and if it all looks ok then I guess you're home in one.

If that is not satisfactory, try

Code:

knoppix xmodule=vesa

That should work with any card but the resolution will be restricted and the advanced features of your graphics card/chip may not be available (like the acceleration). If this does not work at all, I'll have to scratch my head a bit.

If vesa works and the other two drivers don't, try the cheatcodes no3d, noddc and norandr separately and in combination before reporting back.

Since you have the DVD, you could try desktop=kde just to see if that makes a difference.

It may be we have to try specify the horizontal and vertical refresh rates but that's for next time.

If your priority is rescue, then

Code:

knoppix 2

will boot you to the text console (I think Knoppix uses run levels 2 and 5, not 4 and 5) and you can probably cope from there. I start with:

Code:

cat /proc/partitions

which will gives a summary of disks and partitions. You get a lot more information with:

Code:

fdisk -l

including what 'type' the partition is.

**badger99** · 03-09-2011, 08:43 AM

Thanks for your reply Forester.

My graphics hardware consists of Graphics Card: eVGA GEforce GTS 450 1 Gb GDDR5
and dual LG W2052TQ Monitors, 20", resolution 1680x1050.

My posts are being delayed by moderators, apparently because I'm new on the forum, so that is hampering the conversation somewhat. As a result, I've had time to explore my original issue (failed install of ubuntu), and have found that the new HD of my new pc has failed. I'm now waiting for it to be replaced, so my original need for knoppix is somewhat dimished.

However, as soon as the box comes back to me I'll try the things you suggest and will post the results.

Your point about mainstream distributions being able to recognize my graphics hardware is significant and, I will probably have to do extraordinary things to get the graphics hardware configured under ubuntu. Hopefully, getting it going on knoppix may help somewhat.

**Forester** · 03-09-2011, 09:13 AM

Ah, the moderators, of course. Bless them.

GEForce is graphics card/chip. Nvidia is company so we're on the right track,

Bad disk eh ? You can still use Knoppix unless they've taken the whole computer away leaving you with just a pair of monitors. Matched monitor should be OK. Myself, I had trouble trying to use a mismatched pair in cinerama mode but I guess I deserved that.

While you're waiting, if you still have Internet access, you should go onto the 'untu wiki and forums (they are vast) and see if you can find out which driver (the free nouveau or the proprietary driver) 'untu installs.

Use the Ubuntu package site to find out which version of the driver Ubuntu Manky Manatee (Lame Lama, Kackling Kookaburra, whatever) comes with and then the Nvidia site itself to find out if your card/chip needs a newer driver.

If it does, you might try a distribution named aptosid instead.