Fixing Green Artifacts
From Knowledge76
Overview
For some newer System76 computers using Ubuntu 10.04 LTS, users may notice problems with Ubuntu's new Boot Screen program called Plymouth. While the correct resolution can be achieved using the tutorial "Fixing Bad Plymouth Resolution", some systems may now experience Green Artifacts around the Ubuntu Logo. To remove these, follow the steps below.
Warning!
Note that these instructions are to be used at your own risk. This Tutorial is for advanced users only!
Process
uvesafb required v86d package to be installed. Hwinfo package is required for the next step as well.
sudo apt-get install v86d hwinfo
Find out the supported resolution by using hwinfo.
sudo hwinfo --framebuffer
Sample output :
02: None 00.0: 11001 VESA Framebuffer [Created at bios.464] ... Hardware Class: framebuffer Model: "(C) 1988-2005, ATI Technologies Inc. M92" Vendor: "(C) 1988-2005, ATI Technologies Inc. " Device: "M92" SubVendor: "ATI ATOMBIOS" ... Mode 0x0321: 640x480 (+2560), 24 bits Mode 0x0322: 800x600 (+3200), 24 bits Mode 0x0323: 1024x768 (+4096), 24 bits Mode 0x03ee: 1366x768 (+1408), 8 bits Mode 0x03ef: 1366x768 (+2752), 16 bits Mode 0x03f0: 1366x768 (+5504), 24 bits Config Status: cfg=new, avail=yes, need=no, active=unknown
Edit /etc/default/grub to make sure we boot with uvesafb framebuffer. For the mode_option parameter change to your native screen resolution you see from running the above comment (if not just set to 1024×768-24 which is safest. Oh, Netbook user – please exercise some common-sense here) Non relevant lines are omitted for clarity.
... GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nomodeset video=uvesafb:mode_option=1366x768-24,mtrr=3,scroll=ywrap" ... GRUB_GFXMODE=1366x768
Edit /etc/initramfs-tools/modules to include uvesafb by adding the following line.
uvesafb mode_option=1366x768-24 mtrr=3 scroll=ywrap
Force the use of framebuffer:
echo FRAMEBUFFER=y | sudo tee /etc/initramfs-tools/conf.d/splash
Update and you should be fixed up.
sudo update-grub2 sudo update-initramfs -u
