----- Original Message ---- From: Timothy Miller <[EMAIL PROTECTED]> To: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> Cc: Daniel Rozsnyó <[EMAIL PROTECTED]>; Patrick McNamara <[EMAIL PROTECTED]>; [email protected] Sent: Friday, July 28, 2006 9:44:12 AM Subject: Re: [Open-graphics] pci id and openhardware development
On 7/27/06, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: > Be careful about painting yourself into a corner. OGD1 logic testing can > begin with a limited set of VGA modes, but the final OGA1 design in > TRV10/OGC1 will need to come to grips with providing a capability to power-up > running any arbitrary video mode -- because some monitors won't work any > other way. And remember, part of the TRV10 application space is embedded > systems. Cthulhu only knows what display systems it might have to drive. > Don't assume VESA mode compatibility. > Excellent point. So not only do we need a compact piece of C code to generate video programs, but we need to make sure that that and the hardware are general enough to handle just about any practical mode. One function should take a complete set of timing numbers and generate a program; another function can be written to infer blanking time from resolution using a VESA algorithm. This should all be small enough to go into a BIOS PROM. ------------------------ This is the function definition for the progressive scan video modes: int progressive(unsigned int *buffer, unsigned int fb_width, unsigned int fb_height, unsigned int vp_widt h, unsigned int vp_height, unsigned int hfp, unsigned int hsync, unsigned int hbp, unsigned int vfp, unsi gned int vsync, unsigned int vbp, unsigned int viewport); Calling that with the appropriate timing parameters will generate a video controller program to implement that video mode. As a note, I need to add an argument for sync polarity since this needs to be confurable on the fly. I'm not worried about getting the video controller to run at a given mode at boot time. My concern is how to figure out what that mode should be. How do I figure out what mode my old 20" Sun fixed frequency, sync on green, montor connected via a hd15->13W3 converter should run at boot time. Monitors that support DDC aren't a big problem, but ones that don't are very hard. Perhaps in the end, a user configurable default video mode should be available in situations where the card simply cannot tell what to do. --Patrick M _______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
