need to contain the code needed to load the driver to start up the graphics card. Such systems probably wouldn't even have a VGA/VESA Video BIOS.
Early on I was asked what my specific concerns were... I've been a bit busy this week and lost track of this thread but.... As a LinuxBIOS developer and embedded system firmware developer my main concerns are ones of software complexity. Equipment with complex setup requirements are fine from userspace but really suck at the BIOS level. Especially if you are trying to use them with no RAM available. Although from the looks of the rest of the thread it appear too bad. A small ROM table is easily loaded. Currently in LinuxBIOS the 2nd hardest thing to do is enable Video. The 1st is get RAM up and going. But most people who try to use Linuxbios never see the RAM part as its already working and they don't have to touch it. Very few of us have the right docs and are qualified to mess with that code when it breaks. The video however is a major stumbling block. I see it over and over on the LinuxBIOS list. Video is so hard in linuxBIOS because we live in protected mode and pretty much all video bios is in 16-bit mode. So we have to emulate it and they do all sorts of crazy things. And there are many video cards/chipsets to deal with. _Some_ of those crazy things may also have to be done by OG* to be able to have a card that acts like what a user expects from a video card. All this is just the "way it is" in video land right now.. What us LinuxBIOS people would LOVE to see however is a card that you could enable with just a few simple PCI commands to and perhaps loading in a table of values. One troubleing issue for LinuxBIOS is that many new motherboards now do not have serial ports on them they just have USB. To date the serial port has been the workhorse of our debugging methods. To talk to an OHCI or EHCI bridge requires RAM and isn't an option when you are working on the RAM controller. Some boards still have JTAG ports on them but many are removed for the production versions and getting the JTAG info on how to talk to the chips is also hard. The ideal video card for LinuxBIOS work would be one that you could assign an IO address to and then feed it ASCII to have characters show up on the screen black and white in a simple font. Nothing fancy. Now I'm NOT suggesting that any of the current design needs changing or even that anyone needs to think about this ability right now. There is _plenty_ of stuff to accomplish before this matters. I'm just following up on my specific concerns which is that we end up with a card that while flexable is PITA to setup. I think after reading the rest of this thread that most of my concerns are unfounded. -- Richard A. Smith _______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
