Arch Linux

voodoo.child

Member

Registered: 2007-11-01

Posts: 30

nonstandard fb resolution

how can i set framebuffer to a nonstandard resolution (1280x800) that my inspiron can display?

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Alexandru

fwojciec

Member

Registered: 2007-05-20

Posts: 1,411

Re: nonstandard fb resolution

I use "vga=864" parameter in the kernel command line.

AndyRTR

Developer

From: Magdeburg/Germany

Registered: 2005-10-07

Posts: 1,641

Re: nonstandard fb resolution

what framebuffer do you want to use? vesa? afaik vesa doesn't support uncommon resolutions.

voodoo.child

Member

Registered: 2007-11-01

Posts: 30

Re: nonstandard fb resolution

I use "vga=864" parameter in the kernel command line.

nope, it doesn't work. it's not recognized by kernel.

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Alexandru

voodoo.child

Member

Registered: 2007-11-01

Posts: 30

Re: nonstandard fb resolution

what framebuffer do you want to use? vesa? afaik vesa doesn't support uncommon resolutions.

i think i'm using vesafb that comes with kernel 2.6.23-ARCH (default arch kernel).

my card is (if anybody needs this information):
01:00.0 VGA compatible controller: ATI Technologies Inc M52 [Mobility Radeon X1300]

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Alexandru

fwojciec

Member

Registered: 2007-05-20

Posts: 1,411

Re: nonstandard fb resolution

I use "vga=864" parameter in the kernel command line.

nope, it doesn't work. it's not recognized by kernel.

Strange, it works perfectly for me (I just rechecked with the standard Arch kernel).

Edit: I'm using a nvidia card though, maybe that makes a difference.

Last edited by fwojciec (2007-11-04 18:56:43)

fwojciec

Member

Registered: 2007-05-20

Posts: 1,411

Re: nonstandard fb resolution

I'm trying to retrace my steps now with how I came up with this vga parameter...  If you install "lrmi" package you will be able to run a command "vbetest" (as root) to see what the available framebuffer modes for your system are.  On my laptop I get something like this:

[352] 1280x800 (256 color palette)

You need to add 512 to the number in the square brackets to get the number for the vga= parameter (in my case 352+512=864).

If that doesn't work then you'll probably need to patch the kernel with uvesafb (http://dev.gentoo.org/~spock/projects/uvesafb/) since vesa-tng patch is no longer maintained and, if I remember correctly, doesn't apply cleanly to the 2.6.23 kernel.

voodoo.child

Member

Registered: 2007-11-01

Posts: 30

Re: nonstandard fb resolution

I'm trying to retrace my steps now with how I came up with this vga parameter...  If you install "lrmi" package you will be able to run a command "vbetest" (as root) to see what the available framebuffer modes for your system are.  On my laptop I get something like this:

[352] 1280x800 (256 color palette)

You need to add 512 to the number in the square brackets to get the number for the vga= parameter (in my case 352+512=864).

If that doesn't work then you'll probably need to patch the kernel with uvesafb (http://dev.gentoo.org/~spock/projects/uvesafb/) since vesa-tng patch is no longer maintained and, if I remember correctly, doesn't apply cleanly to the 2.6.23 kernel.

vbetest reported some resolutions, none of them is 1280x800. I tried other bigger resolutions, but none of them worked either. the thing with applying patches to kernel is that i have to repatch/recompile the kernel every time it's updated which i don't like.

since I don't need 1280x800 at boot time, can I set the resolution using a command? if not what's the point of having fb modules (like radeonfb)?

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Alexandru

fwojciec

Member

Registered: 2007-05-20

Posts: 1,411

Re: nonstandard fb resolution

Sorry, I don't know enough about framebuffer or ATI cards to answer your specific questions but I understand your reluctance to recompile the kernel whenever a new version comes out.  Maybe this will be helpful: I have found another kernel command line parameter on the web somewhere, something like "video=radeon:1280x800-24" - I guess it won't hurt to try and experiment with something along these lines...