CFT: Graphics support for /boot/loader
rink at FreeBSD.org
Wed Feb 11 05:28:35 PST 2009
On Wed, Feb 11, 2009 at 01:00:58PM +0100, Oliver Fromme wrote:
> It probably makes sense to let the boot loader set up
> graphics mode (including VESA support), so it is already
> active when the kernel comes up. Then the kernel will
> only have to deal with the frame buffer, not with the BIOS.
> That will work on both i386 and amd64 platforms. The only
> drawback is that the mode cannot be changed by the kernel
> once it is running, i.e. you have to stay in that mode
> till reboot.
FWIW, this is exactly what FreeBSD/xbox does; the boot loader is
responsible for setting up the video mode, and all it does is remap the
framebuffer to a more sensible location (the way to do this is just
writing to a register which is the same for any Xbox, and most
bootloaders set the framebuffer to 4MB, which is a bit much for
640x480x16M especially if your machine only has 64MB of memory :-)
> That solution requires support by the loader and by
> syscons. It is my plan to look into that, as soon as the
> basic graphics support in the loader is finished.
I think that is a good approach. Go for it!
Rink P.W. Springer - http://rink.nu
"Chance favours the prepared mind"
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