Re: [gentoo-user] about the vga clause on kernel line of grub.conf

[Paul Hartman <paul.hartman+gentoo@gmail.com>]

On Tue, Mar 2, 2010 at 4:55 PM, Harry Putnam <reader@newsguy.com> wrote:
> For quite a long time I've been using things like:
>  vga=0x31A
>
> On the kernel line in grub.conf
>
> Its a hexidecimal system drawn info in this (partial) chart I found
> somewhere in the kernel documentation long ago.
>
>   ##      640x480 800x600 1024x768 1280x1024
>   ##   256 0x301   0x303   0x305    0x307
>   ##   32k 0x310   0x313   0x316    0x319
>   ##   64k 0x311   0x314   0x317    0x31A
>   ##   16M 0x312   0x315   0x318    0x31B
>
> I've used kernel lines like below in grub.conf:
>                                  (asterisks added)
>  kernel /vmlinuz  root=/dev/hda5  ** vga=0x31b **  video=vesfb:mtrr:3,ywrap
>
> For a very long time. (On occasion I've needed a smaller resolution
> and used 0x317)
>
> But on two recent installs of gentoo as vmware guests, that kind of
> entry isn't doing any good and I'm still being prompted to make a
> choice.
>
> When I hit <enter> as directed a largish chart of what look to be
> octal based settings, flashes by and only the last portion of it
> remains visible.
>
> It has choices like 340, 341 and many other three digit offerings from
> a large chart that shows the resolutions you get with the 3 digit
> choices.
>
> I was unable to find this chart by grepping in the kerne//Documentation
> directory.
>
> Where does the boot process access that chart?
>
> And why is it that the hex system is ignored and this other system
> offered at boot?
>
> I'm successfully using the hex system on my main gentoo machine... but on
> the two recently installed gentoo vmware guests it doesn't work.
>
> It may be relevant that these installs are console only... no X.

From linux/Documentation/svga.txt:

   **  Short intro for the impatient: Just use vga=ask for the first time,
   **  enter `scan' on the video mode prompt, pick the mode you want to use,
   **  remember its mode ID (the four-digit hexadecimal number) and then
   **  set the vga parameter to this number (converted to decimal first).

HTH :)