Re: [gentoo-user] Re: about boot with framebuffer

[Mark Knecht]

On Mon, Jul 4, 2011 at 1:57 PM, Alan McKinnon <alan.mckinnon@×××××.com> wrote:
> On Monday 04 July 2011 13:47:28 Mark Knecht did opine thusly:
>> On Mon, Jul 4, 2011 at 1:40 PM, Alan McKinnon
> <alan.mckinnon@×××××.com> wrote:
>> > On Monday 04 July 2011 11:20:43 Mark Knecht did opine thusly:
>> >> > The way I've been doing this only required `vesa' or
>> >> > `uvesa' and some special kernel line stuff.  None of the
>> >> > X related stuff is necessary.
>> >> >
>> >> > From covici's post... I think I may need to say uvesa
>> >> > where I've been saying vesa.
>> >> >
>> >> > I'm going to try that some time today.  Its already
>> >> > enabled in
>> >> > my kernel
>> >>
>> >> I'm a little confused by his post also, but I've never run a
>> >> machine without Xorg so maybe it's a technical point. With a
>> >> framebuffer I believe you can get a boot screen like the
>> >> Install CD - a bunch of little Tux's across the top - so
>> >> you're doing graphics at that point but you're not running X?
>> >>
>> >> I was curious about this topic awhile back wondering if you
>> >> could run a Gentoo VM with only a framebuffer and get any
>> >> graphics at all, or is it just that the framebuffer is used
>> >> to give you more control over the console font/height/width
>> >> selection.
>> >>
>> >> (I've never run a framebuffer, if that's not obvious!)
>> >
>> > bootsplash does not run under X (well, on redhat it used to, but
>> > you really don't want to go there) - this should be obvious as
>> > you don't see the X start-up sequence happening at early boot
>> > time.
>> >
>> > There are many things boot splash could use for displaying
>> > images
>> > (fbcon etc etc) or even something of it's own invention. I'm not
>> > familiar enough with it to say how it really does it.
>> >
>> >
>> > --
>> > alan dot mckinnon at gmail dot com
>>
>> so does bootsplash run using framebuffer or is it completely
>> different?
>
> I have no idea actually. I could say it must run in a framebuffer-like
> abstraction but that is obvious and doesn't tell you anything you
> don't already know.
>
> Spock is the dev that knows most about these things, a good first
> research point would be to search his name and find related docs.
>
> Sorry I can't be more help - I have the concepts in my head but not
> the facts
>

I appreciate the info. No worries about that.

I think the other point I'm missing here is whether KMS is actually
implementing anything graphical, like a framebuffer, or whether it's
just moving _choices_ about graphics into the kernel and out of X?

I have an Intel i5-661/Intel MB based machine which is the only one I
use KMS for at this time. On that machine I was instructed to use KMS
by the Intel-Gfx devs to get their driver working at all. A nice side
benefit was that it resulted in better text in the console during
boot. However I don't see anything 'graphics like' on that box just
using KMS so I suspect that while I've enabled technology that allows
the kernel to manage graphics that I haven't told the kernel to
actually do so. I don't know though.

All of my other machines are NVidia based and use the closed source
driver so my understanding on those is that KMS doesn't apply.

I'm curious, however, about my Gentoo VMs. Can KMS run on a VM's
kernel and do anything useful there? This is more for learning and not
about any practical need at this time.

Cheers,
Mark