Login window resolution

[Chris G]

On Sun, Mar 22, 2009 at 11:57:45AM -0700, Ray Parrish wrote:
> Mahadi Hasan wrote:
> > My login window resolution is bigger than that of my desktop. My 
> > desktop's resolution is 1024*768. How do I bring the login window 
> > resolution to 1024*768?
> >
> > Regards,
> > Mahadi
> Hello,
> 
> There are a couple of ways that you can try, have a look at the 
> following which contains a few ways of doing what you want. I originally 
> posted it in another group, in an attempt to help a Windows user get 
> Ubuntu installed on his machine, which kept coming up in too high of a 
> resolution to be able to read the screen at boot up time.
> 
> Since I was writing to a green Windows user in that post, I included  
> lot of instructions on the use of sude, etc which you might already know 
> how to do, so skim over those parts if you already know them, and read 
> the parts about changing the boot up resolution which you are interested in.
> 
> For this firsat method, go to System, Administration, Start Up Manager 
> on the Ubuntu menu, and then to the
>  > Boot Options tab of the resulting dialog. This tab allows me to choose
>  > from resolutions anywhere from 600 x 480 to 1600 x 1200 and also
>  > selections of 8 bit to 24 bit for color depth for the login screen.
>  >
>  > Be prepared for a long wait while this program goes through it's
>  > pre-configuration tasks, and post-configuration tasks when you start it
>  > and exit it. I changed one option [resolution from 640x480 to 800x600]
>  > and it kept running it's little progress bar animation back and forth
>  > for the past ten minutes, so I got bored and closed it from the title
>  > bar button.
>  >
>  > OK, it took me a bit of spelunking to discover this, but grub [the boot
>  > up manager] has an optional, not always there, configuration file at
>  > /etc/default/grub which can specify the vga mode for the boot up screen
>  > among other things. This can be set by the use of Start Up Manager, or
>  > alternatively created with a text editor. I had to examine the grub
>  > scripts to find this out. By examining the
>  > /usr/share/pyshare/bootconfig/grub.py script file which determines the
>  > resolution on start up I found the following information.
>  >
>  > """Return the Grub vga code used, as an integer.
>  >
>  > If no code is specified in the config, 769 is returned. [which is 640 
> x 480, 8 bits color]
>  > Grub vga codes:
>  >
>  > Colors 640x400 640x480 800x600 1024x768 1152x864 1280x1024 1600x1200
>  > --------+----------------------------------------------------------
>  > 4 bits |  ?             ?             770          ?               
> ?               ?                 ?
>  > 8 bits | 768         769         771          773           
> 353           775            796
>  > 15 bits | ?           784         787          790           
> 354           793             797
>  > 16 bits | ?           758         788          791           
> 355           794             798
>  > 24 bits | ?           786         789          792           
> ?               795             799
>  > 32 bits | ?           ?              ?              ?              
> 356            ?                 ?
>  >
>  > There is a setting in the /boot/grub/menu.lst file which specifies this
>  > value, and evidently the previously mentioned /etc/default/grub is not
>  > used, as I thought, even 'though the grub.py script looks for that
>  > configuration file. So, according to menu.lst the following applies. -
>  >
>  > ## lines between the AUTOMAGIC KERNELS LIST markers will be modified
>  > ## by the debian update-grub script except for the default options below
>  >
>  > ## DO NOT UNCOMMENT THEM, Just edit them to your needs
>  >
>  > ## ## Start Default Options ##
>  >
>  > And a ways further down from that is this section. Here you can set 
> the video resolution for the default kernel to be booted.
> 
> [Note that for 1024 x 768, 24 bits color mode, you should use vga=792 on 
> the defoptions line below.]
>  >
>  > ## additional options to use with the default boot option, but not 
> with the
>  > ## alternatives
>  > ## e.g. defoptions=vga=791 resume=/dev/hda5
>  > # defoptions=quiet splash vga=792
>  >
>  > Here we see the vga mode being set for the default boot option, and one
>  > # sign marks it as being in use, instead of being a comment like the
>  > lines with two ##'s in the AUTOMAGIC section of the menu.lst file.
>  >
>  > So... to change the default resolution used on your system during start
>  > up,change the vga=nnn to the number representing the resolution you 
> want in
>  > boot/grub/menu.lst, from the table previously pasted in above, and also
>  > make sure that no /etc/default/grub file exists that could modify the
>  > value to one you do not want.
>  >
>  > I also note that it states in the grub.py file that if no code is
>  > specified in the config it will default to the value vga=769 which
>  > corresponds to 640x480, 8 bit colors. Further, to apply that 
> resolution to
>  > all kernels installed and specified in the menu.lst file, instead of
>  > just the default kernel, you would need to change the following section
>  > of the AUTOMAGIC section to include the vga=792 setting as shown below,
>  > and you would leave out the change to the defoptions section above,
>  > which only applies to the default kernel in use.
>  >
>  > ## default kernel options for automagic boot options
>  > ## If you want special options for specific kernels use kopt_x_y_z
>  > ## where x.y.z is kernel version. Minor versions can be omitted.
>  > ## e.g. kopt=root=/dev/hda1 ro
>  > ## kopt_2_6_8=root=/dev/hdc1 ro
>  > ## kopt_2_6_8_2_686=root=/dev/hdc2 ro
>  > # kopt=root=UUID=d87df8a8-9b0a-46c9-82ef-7c5503f46c62 ro vga=792
> 
> [once again, for a resolution at boot up of 1024 x 768 in 24 bit color 
> mode, use vga=792 on the configuration line above.]
> 
> There you go, three ways to set the resolution of your start up screen. 8-)
> 
.... but isn't that "start up screen" as opposed to the gdm login screen?

-- 
Chris Green