Subject: Re: wsdisplay on vesafb is slow
To: Aaron J. Grier <agrier@poofygoof.com>
From: Michael Lorenz <macallan@netbsd.org>
List: current-users
Date: 12/28/2006 03:29:44
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Hello,

On Dec 28, 2006, at 00:35, Aaron J. Grier wrote:

> On Wed, Dec 27, 2006 at 04:46:51AM +0300, Valeriy E. Ushakov wrote:
>>> What exactly is the excuse why vesafb must (according to you, and
>>> evidently Michael too) not work that way?  The fact that it can't is
>>> responsible for a major longstanding security hole in the i386 port.
>>
>> I agree with Thor here.  I have little clue about vga text mode, but
>> wscons distinguishes (WSDISPLAYIO_SMODE) between mapped and emulated
>> (i.e. text console) modes.  Just treat vga text mode as a peculiar
>> "acceleration" for the emulated mode and switch to the framebuffer for
>> the mapped mode.
>
> can multiple drivers be attached to the same wsdisplay device, with
> wscons handling the passoff between them?  IE let vga handle textmode,
> then replace it with vesafb when the appropriate ioctl is done on
> wsdisplay?

Not really.
I think what uwe meant is to use text mode when in terminal emulation 
mode and graphics otherwise.

>> It makes life easier for the driver author to always run in the same
>> framebuffer mode, so that switching to the wscons mapped mode in the
>> driver is basically a no-op, but that's a weak excuse :)
>
> sounds like the goal is to have a single VESA driver which can flip
> between text and graphics modes within a single driver.  I'll poke at
> it, but really my goal is faster graphics access, which will let me
> jettison full-blown X in favor of the much more svelte nano-X.

And then there are situations where we can't really use VGA text mode ( 
like on many OpenFirmware machines ) but that's not vesafb's scope ;)

have fun
Michael
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