epia m vga + memcpy failed
Ronald G. Minnich
rminnich at lanl.gov
Tue Sep 7 22:11:01 CEST 2004
On Wed, 8 Sep 2004, Peter Stuge wrote:
> On Tue, Sep 07, 2004 at 08:15:47PM -0400, Trellix78 at aol.com wrote:
> > That message is from the original freebios. I was thinking that
> > shadowing is not corretly set up and that maybe the
> > segment is write-protected. After setting up shadowing,
> > the chipset my turn on write protection by default, anyway. I
> > don't know how to turn write protection off specifically for the
> > C00000 segment. So far, the only reference that I can find about
> > write protection is in the Pentium developer's manual. It says to
> > have bit 16 of CR0 be zero to turn off write protection.
> That's controlled by the descriptor table flags for the particular
> descriptor in use. (cs/ds/es)
There are north bridge issues. There are lots of ways in the x86
architecture for writes to fail ...
> Trying to write to protected memory would cause a page fault that
> LB probably doesn't recover from. (Are PF:s handled at all?)
no, that's not necessarily the case ...
More information about the coreboot