Re: patch: fast console output ioctl(PIO_DISPLAY)

Martin Mares (mj@albireo.ucw.cz)
Fri, 17 Jul 1998 21:38:54 +0200


Hello,

> Another solution: to map VGA display memory in user space. KDMAPDISP
> looked promising, but it wasn't implemented. Another problem would
> be that this would be hardware-dependant way.

Mapping of video memory is not as simple as it looks as you need to handle
console switches.

> I made a new console ioctl() call named PIO_DISPLAY. The user
> programs prepares a image buffer and the ioctl call then simply
> copies it directly to screen. It's still very unoptimized (I'm
> planning to write x86 assembly for it) but it easily redraws the
> screen 300 times per second. The benefits are that it is hardware
> independent and binary clean (you can output _any_ character).
[...]
> Is there some existing way to speed up console output, what I missed
> (something that would make my patch useless)?

Just write to /dev/vcsa instead.

Have a nice fortnight

-- 
Martin `MJ' Mares   <mj@ucw.cz>   http://atrey.karlin.mff.cuni.cz/~mj/
Faculty of Math and Physics, Charles University, Prague, Czech Rep., Earth
"Press any key to quit or any other key to continue"

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