Saturday, 21 July 2012

Debian Wheezy corrupted graphics

Debian Wheezy Fresh install black/corrupted X and Terminal screens

I've been trying to install Debian wheezy to a E525 Thinkpad Edge. This has an AMD chipset and a Radeon graphics card onboard. Install (from Net image) using amd64 works just fine but on first boot, the X windows is garbled/corrupts/speckled and unusable after the first reboot.

The problem is that the graphics card (Radeon HD6500D) needs the firmware-linux-nonfree package, but how to drop to a terminal to install it.

The easiest way to do it is to stop the kernel from attempting to modeset (this happens before X-windows starts). The usual way to see when this happens is when the boot messages change from a bigger font to a smaller font. We want to stop this from happening.

When the laptop boots, stop it at the grub prompt, and press e to edit the boot parameters

Then add the option radeon.modeset=0 at the end of the linux stanza:

Press F10 to boot. Cntrl-Alt-F2 should bring up a terminal. Login as a user and su to root.

# cp /etc/apt/sources.list /etc/apt/sources.list.stock.yyyymmdd

Edit /etc/apt/sources.list and add non-free to the end of the line starting deb and ending "wheezy main". You do not need to add non-free to the lines.

My /etc/apt/sources.list line now looks like this:

deb wheezy main non-free

# apt-get update
# apt-get install firmware-linux-nonfree

Reboot and enjoy. You should not need to edit the grub parameters again. Note that the E525 also needs the firmware-realtek adding to it to get the wireless to work.


John Smith said...


This was the most concise and newbie-friendly explanation on how to fix the fresh wheezy install on my ATI-GPU sporting laptop.

J. Oren Tysor said...

+1 to John Smith. I'm curious, how did you go about finding this out?

tng said...

I'm a tinkerer and have to play with modeset more than I should have to.

I knew the instructions out there weren't great and thought I could write some more concise ones.

Glad to be of help

gour said...

Thank you very much for you post!!!

After deciding to finally leave ArchLinux I did try for a short time to use Free(PC)BSD, but soon decided to go back to Linux...tried Linux Mint & LMDE, but did some more research and gave up idea to use (X)Ubuntu and decided Debian would be my next distro.

Stable is a bit too old for me, I want stability and less adin/tweaking than with Arch (& Gentoo), so 'testing' seemed as perfect match. :-)

However, tried with beta3 wheezy installer and always got corrupted display. :-(

I did install 3 times - 1st time normal, then next time disabled 'laptop tools' and 3rd time 'desktop environment'.

After last fail, I did some Google which led me to your post and saved my life as well as brought new user to Debian. ;)


MattD said...

Thank you very much. I have been messing with this laptop for at least 5 hours over the last few days trying to figure this out.

I tried nomodeset to no avail, I didn't know about radeon.nomodeset option.

Thanks again!