Date: Thu, 28 Dec 1995 15:11:03 +1030 (CST) From: Michael Smith <msmith@atrad.adelaide.edu.au> To: jkh@time.cdrom.com (Jordan K. Hubbard) Cc: msmith@atrad.adelaide.edu.au, jdli@linux.csie.nctu.edu.tw, freebsd-hackers@freebsd.org Subject: Re: syscons driver Message-ID: <199512280441.PAA01069@genesis.atrad.adelaide.edu.au> In-Reply-To: <277.820123198@time.cdrom.com> from "Jordan K. Hubbard" at Dec 27, 95 07:59:58 pm
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Jordan K. Hubbard stands accused of saying:
> From the achievement standpoint, it's not been that bad. The major
> criticism of it seems rather to be that it's insufficiently general -
> you need a low level shim written for each type of gfx card chipset.
Agreed, although I suspect that you can tell it to assume a 'generic'
VGA interface.
> Given the speed at which new video cards are appearing on the market,
> I can easily see serious disadvanges to this and would much prefer an
> API that let me talk to *any* "Generic VGA" card at 640x480
> resolution. I'm not sure if that's possible with syscons, but it'd
> certainly be the goal to shoot for. Anything else is just signing
> up for a long-term pain in the butt.
You certainly can kick syscons into any of the majorish video modes :
(from <machine/console.h>)
#define M_VGA11 26 /* vga 640x480 2 colors */
#define M_BG640x480 26
#define M_VGA12 27 /* vga 640x480 16 colors */
#define M_CG640x480 27
#define M_VGA13 28 /* vga 640x200 256 colors */
#define M_VGA_CG320 28
...
#define SW_VGA11 _IO('S', M_VGA11)
#define SW_BG640x480 _IO('S', M_VGA11)
#define SW_VGA12 _IO('S', M_VGA12)
I would presume that there's some way of mapping the console video memory
into the process's address space, or alternatively it would be neccessary
to implement an ioctl to copy regions back and forth (yucky).
> Jordan
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