[coreboot] I've turned on paging as a test

David Woodhouse dwmw2 at infradead.org
Wed Mar 12 18:12:02 CET 2014


On Mon, 2014-03-10 at 16:41 -0500, Jonathan A. Kollasch wrote:
> On Mon, Mar 10, 2014 at 02:33:41PM -0700, ron minnich wrote:
> > And locked out page zero. And we trap.
> > 
> > So, first question, can we move X86_BDA_BASE to somewhere other than 0x400?
> > Anyone know?
> 
> The BIOS Data Area is not movable.

The *physical* address of the BDA is not movable.

However there are no constraints on what its *virtual* address should
be, while you're running in your own code with paging turned on.

Even if you generally have a 1:1 mapping of virt->phys addresses, you
could still set up a mapping for the zero page at a different virtual
address.

-- 
dwmw2

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