Re: l4ka Digest, Vol 30, Issue 12

[Carl van Schaik]
> We have a completely modified VM implementation to Pistachio which
> makes larger than 4GB physical mappings trivial to implement. It has
> been added since there was no reason not to support it.

You wouldn't mind sharing some insight on this, would you?

> Sure, Pistachio sigma0 can map pages it can't access, it just means
> that you complicate the issue of setting up and managing page
> attributes (uncached, write-through etc) since sigma0 can't modify
> the attributes of those pages.

I wouldn't say that it complicates the issue more than it already is.
Mind you, MemoryControl() is really badly defined right now.  The way
you describe things with page attributes assumes one particular
definition of how these things are supposed to work.  If you remember
the proposed MapControl() syscall (internal mail, not on l4ka@ mailing
list), you might also remember a lengthy mail where I among other
things described how managing page attributes from sigma0 is a
terribly, terribly bad idea.

	eSk