Red Hat Bugzilla – Bug 24346
GUI install display offset
Last modified: 2007-04-18 12:30:47 EDT
I did a gui install. The video is a RIVA TNT2 with a Dell flat panel
(FP1700). The display was offset about 0.3 inches to the right which made
it difficult to see/use the scroll bar on the right side.
Video setup worked OK with both the video card and the display being
recognized correctly and selecting 1280x1024 resolution properly positioned
on the panel.
If you try passing it the proper framebuffer vga=nnn value on the boot
commandline for the installer, does it come up ok?
These values are in the Documentation/ directory of the kernel source, in a file
about the framebuffer. I would try the value for the 1280x1024 mode that works.
Huh?? Framebuffer settings??
I am talking about the anaconda gui install (VGA?) screen which is offset. I
just booted the install disk (like any other user) and it came up offset to the
After installation, the screen came up fine with the selected 1280x1024.
You can boot the installer with a vga=xxx command line to tell the kernel
framebuffer what resolution to use. The installer will use this mode.
If you specify this it might run the installer at 1280x1024 and work around
the image shift problem.
I tried "nofb" -- no different.
I also tried "lowres" -- this went to text mode.
I have no idea what to specify for "vga=xxx"
Try passing vga=793 at the boot prompt. That will put the kernel in 1280x1024
resolution and 16 bit color.
From the /usr/src/linux/Documentation/fb/vesafb.txt file, here are the valid
framebuffer modes for the kernel:
| 640x480 800x600 1024x768 1280x1024
256 | 0x301 0x303 0x305 0x307
32k | 0x310 0x313 0x316 0x319
64k | 0x311 0x314 0x317 0x31A
16M | 0x312 0x315 0x318 0x31B
These numbers are in hexadecimal, so if you convert 319 (Hex) to decimal, you'll
get 793. I use the Scientific Calculator in KDE to do the conversions easily.
See if that doesn't make the installer line up correctly. You should see the
installer appear in a 800x600 window in the middle of the screen.
*** Bug 25158 has been marked as a duplicate of this bug. ***
Sorry but specifying vga=793 at the INSTALLER boot prompt had exactly zero
I also tried nofb vga=793 and while I got no framebuffer stuff during kernel
bootup, XFree still used the frame buffer driver and had the right shift offset.
BTW, while 25158 MAY be a dup of this bug, I could get around the LEFT shight by
Ok, one last try. Try passing vga=794 at the boot prompt. If this doesn't
work, I'm out of ideas.
I don't think this is anything we can do in software to fix this.