Messages in this thread | | | Date | Thu, 24 Jan 2008 15:08:28 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH] x86: Construct 32 bit boot time page tables in native format. |
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Jeremy Fitzhardinge wrote: > H. Peter Anvin wrote: >> Yeah, and it's ugly for the kernel proper, so that bit is a >> no-brainer. It's just a matter of hammering out the details. >> >> It doesn't sound from the above that you have any opinion either way >> about reusing the initial page tables or creating a new set, as long >> as they're in the same format. > > Right. > > Xen provides a initial set of pagetables in the appropriate format, so > what head.S generates is moot. For simplicity I graft the Xen-provided > pagetables into swapper_pg_dir in xen_start_kernel, so it is the > functional equivalent to the head.S pagetable construction. > > We also don't (yet) support PSE, so that's a non-issue for us too. >
While we're mucking around in this area, there is another thing which we should eventually get around to fixing:
we need a set of page tables with an identity mapping as well as the kernel mapping, for trampolining (during startup, but also during things like ACPI suspend/resume.) Right now, we let those be the swapper page tables, but that's probably not really a good idea, since it can hide bugs.
-hpa
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