[coreboot] VGA and Graphics

Zoran Stojsavljevic zoran.stojsavljevic at gmail.com
Mon Apr 3 09:24:41 CEST 2017


> *VBT is not code, it's a table* -- that's what the T is -- and you can
create it any way you want.

Not going to say more, anyway. Just to point to the standard:
https://en.wikipedia.org/wiki/VESA_BIOS_Extensions

To clever enough! ;-)

Zoran

On Mon, Apr 3, 2017 at 2:38 AM, ron minnich <rminnich at gmail.com> wrote:

> As for graphics startup, here's what I learned when I was doing this in
> 2012/2013: the kernel could start sandy and ivy with no vbios needed.
> However, I have been told that the veil of secrecy has started to draw a
> bit closer in subsequent chipsets, and that something like a VGA BIOS/GOP
> has to run or graphics will not work. I really don't know, I have not
> looked at this in over 3 years.
>
> Todd, just to make sure we're on the same page, VBT is not code, it's a
> table -- that's what the T is -- and you can create it any way you want.
>
> Also, as for numbers: the fastest graphics startup, by far, was when we
> had coreboot- based startup with configuration specialized to the chromeos
> laptop. How fast? At one point we had a pixel booting to chromeos prompt in
> 2.7 seconds, reduced from 7.7 seconds when linux did the graphics init.
> We've seen that the linux graphics init is highly concurrent and
> generalized, and that tends to mean slow. Of course this was all far faster
> than the 8086-mode vga BIOS supplied by "the vendor". But we were a bit
> surprised to see how much faster coreboot was than the linux kernel.
>
> I doubt this speed difference matters any more, since boot time only needs
> to be "fast enough" nowadays and 10 seconds seems to do it for most people
> -- plus, any 5-second advantage in boot time vanishes as soon as you go to
> your first web page.
>
> ron
>
>
>
> On Sun, Apr 2, 2017 at 5:31 PM ron minnich <rminnich at gmail.com> wrote:
>
>> So, I'll mention go userland one last time, for a simple reason: I have
>> it on good authority that at some places, saying you have a go userland
>> instead of a c userland checks a check box on a security checklist. I think
>> that's a sensible decision, having watched all the awful ways that C
>> programs tend to go wrong :-)
>>
>> ron
>>
>
> --
> coreboot mailing list: coreboot at coreboot.org
> https://www.coreboot.org/mailman/listinfo/coreboot
>
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