I created a package , for what I believe is a usable driver for the Chrontel CH7317 , SDVO to VGA converter.
The vBIOS appears to work. Windows finds it ok and seems all is well.
When I install the driver , the screen will go black on next reboot (Reminds me of an issue with a Montevina Design). I am sure the system is booted . Is it possible the driver is comming up "pointing?" at the wrong port somehow (LVDS only mode) ?
I am sure this is easy, I am missing an option under a table somewhere.
My guess is that you left the LVDS in your port list and have it as the first port. The driver has to assume that an LVDS is attached and will make it the primary video.
A couple of things could help here-
1. change the port order to have the SDVO first. Also you could consider using "display detect" so the driver will look on the SDVO port for a valif display attached. This is best and least problematic solution.
2. Set CLONE mode as default startup mode and that way BOTH the LVDS and SDVO will be primary and you will get video on the VGA. The downside to this is that you will potentially limit your display modes.
If the above does not change anything then it may also be that the driver is NOT seeing a valid configuration (installation falied to update the registry due to a build issue or ???) and is loading but going into its default mode. It could also be that your VGA display says it handles 640 x 480 mode or 800 x 600 but does not (Windows sometimes starts up VGA displays in the lowest resolution possible- some displays do not handle the modes they "say" they do through their EDID). You could see by attaching an LVDS and a DIFFERENT VGA display to see what might be going on.
Well, it appears that the issue is resolved in the IEMGD_1_5_2_GOLD_1816 .
Also, just for completeness, in this version of the CPU you can not run this board in clone mode due to lost code for some work arounds.
So the new driver in this package fixes my problem... the VBIOS itself wasn't the fix.