Subject: struct videomode
To:, Michael Lorenz <>
From: Garrett D'Amore <>
List: tech-kern
Date: 03/03/2006 13:59:33
In order to implement a framebuffer driver for Radeon boards, I need a
reasonable database of video timings.  (Yes, I know I could use EDID and
DDC, but I'm not that far yet.  And not all monitors support these.  And
some folks might want to use a resolution other than what the monitor

Anyway, in dev/ic/ there is videomode.h, which has the structure I need
to use.

There are two questions here.  First, anyone object to me moving this to
dev/ic/videomode/ and placing a .c file here with a reasonable database
(an array of struct  videomode)?  (Actually, the .c will be generated by
an awk script, from a file containing a bunch of XFree86 Modeline
definitions -- such as
xsrc/xc/programs/Xserver/hw/xfree86/etc/vesamodes.)  Both the source
file(s) and the awk script will also be in that new directory.

Second, struct videomode has a void* member called misc_data.  I want to
replace this with a const char *, which will be a "name" for the mode in
the form "XxYxR" where X = x resolution, Y = y resolution, and R =
vertical refresh rate.  So you get a string like "800x600x60" or

This would allow device drivers to locate potential video modes by
scanning for them in the list by name.  The name would presumably come
from some other configuration mechanism, such as device properties, etc.

Right now the only place struct videomode is used is in vga_raster.c and
machfb.c.  Neither of them initialize or use the opaque misc_data member.


Garrett D'Amore, Principal Software Engineer
Tadpole Computer / Computing Technologies Division,
General Dynamics C4 Systems
Phone: 951 325-2134  Fax: 951 325-2191