On Thu, 2006-05-04 at 16:40 -0400, Jon Smirl wrote: > On 5/4/06, Matthew Garrett <[email protected]> wrote: > > Bjorn Helgaas <[email protected]> wrote: > > > > > There's already a "rom" file in sysfs. Could vbetool and friends > > > use that? > > > > Not if you have multiple graphics cards. > > Not true, the rom attribute maps the ROM into PCI space where ever the > kernel tells it to and reads it from there. It is the PCI VGA > emulation feature that forces the ROM to appear at C000:0. You can > have the ROM mapped and VGA emulation turned off. It doesn't matter -- you can accomplish the same thing with e.g. libx86emu and simply mapping the option rom to 0xc0000. But you want to do that in userland, not in the kernel. > This brings up another major point. X changes the PCI VGA emulation > routing from user space, another thing that it should not be doing. I > have posted patches before providing a sysfs VGA attribute on class > VGA devices. By setting the attribute to 1 you can control the active > VGA emulation device. > > This is yet another way that user space can mess up the kernel. If VGA > routing is changes under fbdev (my attribute notifies fbdev, the fbdev > code for processing the notification did get checked in) then the > console will screw up. And this change allows userland to avoid doing that. > The usual screw up is that the console goes > blank because hardware fonts are not setup correctly on the new > console. And that's completely unrelated to this problem. -- Peter - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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