Re: VESA FBconsole driver?

Kendall Bennett
2003-03-13T23:30:45Z

Petr Vandrovec <vandrove@vc.cvut.cz> wrote:

> It was some guy from Finland and I'm under impression that this
> project is dead, because BIOSes were proven to be completely
> unstable in Linux environment.

We have been using the VESA BIOS successfully in user land under Linux
for a long time now, and I would say that the BIOS'es are just as stable
under Linux as under any other platform (you just need to know how to
code around all the screwed up versions out there ;-).

> Try searching linux-fbdev-devel@lists.sourceforge.net archives,
> maybe you'll find something.

Ok, I will look. I tried searching the kernel lists but did not get
anywhere. Don't suppose you recall the name of this project?

> Maybe FreeBSD is too ia32 centric?

Perhaps, but vm86() but it's nature is ia32 specific anyway ;-)

> > Is there any reason why the vm86() services in the Linux kernel cannot be
> > used by other kernel code? Has anyone made an attempt to update the
> > vm86() services to support this?
>
> Why you need it? To run some parts of VGA BIOS? Why you cannot run
> them from userspace task? I think that it is much easier,
> especially now when initramfs is here.

The reason why it would nice is so that the VESA FBconsole driver (and in
fact all the FBconsole drivers that use the real mode BIOS to set an
initial display mode) can restore that mode correctly when an application
exists and restores the console. Right now it is up to the application
program to restore the console, as the kernel has absolutely no way to do
it. If that program has not way to restore it (old SVGALib code for
instance) or the application crashes, you are stuck with a black screen
if you are using a framebuffer console. If the kernel knew how to call
the BIOS to restore the mode, this problem could be completely eliminated
and services could be provided to properly restore the system state when
console graphics programs crash (or the X server for that matter if it
crashes and does not properly clean up).

Regards,

---
Kendall Bennett
Chief Executive Officer
SciTech Software, Inc.
Phone: (530) 894 8400
http://www.scitechsoft.com

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