[rescue] 1920x1080 @ 60 Hz on a Creator 3D under NetBSD (Was: FB resolution in PROM)

Romain Dolbeau romain at dolbeau.org
Sun Nov 15 09:11:32 CST 2015

2015-11-04 15:31 GMT+01:00 Romain Dolbeau <romain at dolbeau.org>:

> I've even installed NetBSD 7 on a spare disk, but unfortunately the driver
> won't take an arbitrary resolution, only PROM or EDID - and it seems my
> adapter is one of those scr*w*ng EDID :-(

Well, the FFB hardware does support 1920x1080 at 60 :-)

Since none of my cables seemed to let the EDID through, I dumped it on a
Linux box and baked the EDID block directly into the NetBSD kernel. Ugly
but it works. At this point, the NetBSD FFB driver would change the
resolution and the screen would lose sync, claiming "no signal". After many
trials at various resolutions, it turns out that I need to hardwire
EDID_VIDEO_INPUT_COMPOSITE_SYNC to set, otherwise nothing gets displayed.
But with this additional hack, I can get both VESA 1920x1080 (148.5 MHz)
but also the monitor EDID value, which is the same resolution but at 173
MHz of pixel clock.

Now, back to the PROM :-)


Romain Dolbeau

More information about the rescue mailing list